Experiment InstructionsCE 600 Continuous Rectification 10/2009 All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 CE 600 CONTINUOUS RECTIFICATION Experiment Instructions Dipl.-Ing. (FH) Klaus Schröder Please read and follow the safety advices before the first installation! Version 2.2 Subject to technical alternations i 10/2009 CE 600 ii CONTINUOUS RECTIFICATION . . . . . . 18 2. . 3 All rights reserved. . . . . . . . . . . . .1 Proper use . . . . . . . . . . . . . . . 1 1. . . 18 3 Safety . . . . . . . . . . . . . . . .4. . . . 29 iii . . . . .2 Operating the program . . . . . . . . . .2 Teaching instructions. . . . . . . . . . . . . . . . . . . .1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Hazards to the unit and its function . . . . . . . . . . . . . . . . . . . . . . . . . . . G. 8 2.2 Control cabinet . . . . . . . . . 21 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. 10 2. . . .4 Data acquisition program. . . . . 8 2. . .N. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. . . . . . . . . . .10/2009 CE 600 CONTINUOUS RECTIFICATION Table of Contents 1 Introduction . Barsbüttel. . . . . . . . . 12 2. . . . . . . . . . . . . . . . .1. . . . . . . . . . . . . . .T. . . . . . . . . . . . .U. . . 20 4 Theory .1 Components for the thermal process . . . . . . . . . . . . . . . . . . . . .2 Rectification . . . . . . . . . . . .5 Commissioning . . . . . . . . . 19 3. . . . . . . . . . . . . . . . . . . . . . . . . 22 4. . . . . . . . . . . . .1 Health hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.3 Equipment Functions and Components . . . . . . . . . . . . . . . .4. . . . . . . . . . . . . . . . . Germany 10/2009 2 Unit Description . . . . . . . . . . . . . . . . Gerätebau. . .3. . . . . . . . . . . . . . . . . . . . .3 Azeotropic mixtures . . . . . . . . .1 Distillation . . . . . . . . . . . . . . 5 2. . . . . .1 Basic principles . . . . . . . . . . . . . . . .6 Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. . . . . . . . . .2 Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Process diagram . . . . . . . . . . . . . . . . . . . . . . .1 Installing the program . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. . . . . . . . . 24 4. . . . . . 3 1. . . . . .1. . . . . . 13 2. . . . . . . . 1 Preparing the unit . . . . . . . . . . . . . . . . . . . . . . .2. . . . . . . . . . . . .2 Refitting the columns . . . . . . . . . . . . . . . . .1 Notes on performing experiments . . . . . . . . . . . . . . . . . . . 68 . . . . . .1 Tanks. . . . . . . . . 60 6. . . . . . . . . . . . . . .1 Recommended ethanol/water mixture. . . . . . .3 Mixing behaviour. . 53 6. .4. . . 65 6. . .2. .3 Experiment variants. .4 Experiments . .1.2 Pumping from the feed tanks into the evaporator . . . . . . . .2 Comparative experiments. . . . . . . . . . . . . 47 6 5. . . instructions for performing . . . . . .2 Accessories for performing experiments . . . . . . . . . .5 Experiments . . . . . . . . 64 6. . . . . . 39 5. . . . . . . . . . . . . . . . . . . . . . . . . 37 5. . . . . . . . . . . . . .2. . . . . . . . . . . . . . . . . .2 Measuring instruments . . . . . . . . . . . . . . . . . measuring cups. . . . . . . . . . . . . . . . . . . variants.1 Material values . . 39 5. . . . . .1. . . . . . . 58 6. . . 47 5. . . . . . .2 Determining concentration by density and temperature . . . . . . . . 47 5. . . . . . . .6.1 Tank volumes . . . . . . . . . . . . .2. . . . . . . . . . . .1. . .1 Notes on performing experiments. . . . 31 5. . . . . . . . . . . . . experiment series . . . . 31 5. .2. . . .6. . . . . . 38 5. . . . . . .operation with vacuum . . . . . . . . . .2 Notes on performing experiments .10/2009 CE 600 5 CONTINUOUS RECTIFICATION Experiments . .continuous mode . . . .1. .2 Definition of background conditions. . 31 5. . . . . .5. . . .batch mode. . . . . . 53 6. . . . . .1 Requirements for the water / water hardness. . . . . . . . . . . . . . . . .operation at ambient pressure . . . . . . . . . . . . . 57 6. . . . . .2. . . . 59 iv 6. . . . . . . . . . . . . . . . . . . . . . . . . .6. . . . . . . . . . 50 5. . . . . . .6 Practical tips . . . . .1. . . . . . . . . . . .6. . . 48 5. . 44 5. . . . . . . . . . . . 44 5. . .4. . . . . . . . . .with ethanol/water mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6. . . . . . . . . . . 37 5. . . . . . . . . . . . . . . . . . . . . . . . . . .4 Reuse of input substances . . . . . . . . . . . . . . experiment series . . . . . . . 51 Experiments . . . . . .5 Hose lengths .Preparations. . . . . .1 Method of operation of the unit . . . . . . . .3 Example of a batch experiment series . . . . . . . . . . . .6.3 Bottom product cooling at the end of an experiment . . . . . . . . 41 5. . .4 Example of a continuous experiment series . . 37 5. . . .6 Comments. 111 Appendix . . . . . . . . . . . . . . . . . . . . . .3. . V3. . . .3 Abbreviations and symbols . . . . . .2 Experimental setup . . . . . . . . .3 Performing the experiment . . .5 Evaluation . . . . . . . .3. . . . . . 119 8 7. . . . . . . . . . . . . . . . . . . . . . Germany 10/2009 6.3. . . . . . . V7 . . . . .3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6. . . . . . . . . . . . . . . . . . . . .10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved. . . . . . . . . 70 6. . . . . . . . . . . . . . . . . . . . .1 Abbreviations used . . . . . . 78 6. . . . . . . . . . . . . . . . .4 Measured values . . . . . . . . . . . . . . .3 Example of a batch experiment. . . . . 115 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 7. . . . . . . . . .4. . . . . . . . . . . . . . . . . 115 7. . 93 6. . . . . . .1 Technical data . . . . . . . 116 7. . . . . . . . . . . . . . .T. . . . . . . . . . . . . . . . . . . . .6 Comments. . 119 Index . . . . . . . . . . 97 6. . . . . . 93 7 6. . Barsbüttel. . . . . . . . . 93 6. . . .4 Example of a continuous experiment. . . . Gerätebau. . . . . . . . . . . . . . . . . . . . assessment . . . . . . . . . . . . . . . . .4. . . . .2 Worksheets . . . . . . . . . assessment . . . .1 Experiment aims . . . . . . . . . . .4. . . . . . . . . . . . . . . . . .3.2 Symbols used . . . . . . .4. . . . . . . . . . . . . . . . . 70 6. . . .N. . . . .3. . . . . . . . . . . . 121 v . . . . . . . . . . .3. . . . . . . . . . . . . . . .4. . . . . . . . . . . . . . . . . . .3 Performing the experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 6. . . . . . . . 102 6. . . . . . . . . . . . . . . . . . . . . . . . .2 Experimental setup . . . 73 6. . . . . . . . . . . . . . 71 6. .1 Experiment aims . . . . .4. . . . . . . . . . . .4 Measured values . . . . . . . . . . . . . . .3. . 93 6. . . . . . . G. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Evaluation . . . . . . . . . . .U. . . . . . . . . . . . . . . . . . 10/2009 CE 600 vi CONTINUOUS RECTIFICATION . All rights reserved. The packed column features a port half way up.U. Gerätebau.T. Either a sieve plate column or a packed column can be used for the experiments. The unit consists of an electrically heated bottom in which the initial liquid mixture is heated and evaporated. A heat exchanger enables the pumped-in liquids to be pre-heated. liquid mixtures that consist of mutually soluble fluids are often separated by thermal processes.N. The steam rises through a column and is subsequently condensed in a water-cooled condenser.10/2009 CE 600 1 CONTINUOUS RECTIFICATION Introduction In physical-chemical engineering. the sieve plate column features three ports at different heights. G. The separation behaviour varies depending on which port is chosen. Germany 10/2009 The Continuous Rectification CE 600 experimentation unit enables liquid mixtures to be thermally separated by means of rectification in the experiment. all of the condensate can be drained off as the top product. For that purpose. 1 Introduction 1 . A glass filter pump can be used to generate a vacuum in the entire tube system for vacuum rectification. permitting continuous running of experiments. From here. A pump can be used to pump mixture into the column. Barsbüttel. or all or part of it can be returned to the column. The main processes are distillation and rectification. The column head incorporates a port for the return flow of distillate. This enables the available measurements to be automatically recorded and documented. Potential series of experiments for the recommended ethanol/water material mix are demonstrated. 2 1 Introduction . The method of operation is described in order to illustrate the possibilities and limits of the unit. to control the unit from a self-supplied PC using software supplied with the unit. Two experiments from the series are demonstrated. evaluated and commented upon in detail by way of example. It is a good idea.10/2009 CE 600 CONTINUOUS RECTIFICATION The unit can be operated locally from the control cabinet. 3 different infeed heads selectable • Reduction in the number of plates in the sieve plate column • Operation at ambient pressure or under vacuum • Operation with or without feed preheating The instruction manual provides detailed instructions on performing the experiment. The range of experiments covers the following variants: • Discontinuous (batch) or continuous • Sieve plate column or packed column • Sieve plate column. however. Gerätebau. page 115). 1 Introduction 3 . G.U. page 47. The main effects can be demonstrated in one hour’s operation. Germany 10/2009 1. Control of the unit requires sound experience in the performance of experiments.N.T.10/2009 CE 600 1. The estimated time required to perform an experiment is between four and five hours (from charging the unit and putting it into operation.6. Areas of application of the unit are: • Demonstration experiments The tutor operates the prepared system while a small group of five to eight students observes. A suitable laboratory facility is required to operate the unit (for water quality see chapter 5.2 The unit is designed so that all operations are mostly visible and can be observed. determining the masses and concentrations through to draining the unit at the end). Teaching instructions All rights reserved.1 CONTINUOUS RECTIFICATION Proper use The Continuous Rectification experimentation unit CE 600 is intended solely for educational purposes and not for industrial production. The reaction of the unit to changing conditions is demonstrated.1. recording data. The unit is for educational use in the field of thermal process engineering and apparatus construction. Barsbüttel. for required cooling water flow see chapter 7.1. • Practical experiments Small groups of two to three students can also perform experiments independently. a single. the experiments should be performed by two students. detailed training by a specialist GUNT engineer may be necessary and useful. The influence of changing conditions on the measurement results can be determined by way of experiment series. Because of the complexity of the experimentation unit and the demanding subject. In continuous mode. For batch experiments. experienced student may also operate the unit.10/2009 CE 600 CONTINUOUS RECTIFICATION • Project work The unit is especially well suited to carrying out project work. 4 1 Introduction . 1. Information on the unit circuitry and instructions for performing the experiment in its different variants are provided in chapter 5. Barsbüttel.10/2009 CE 600 CONTINUOUS RECTIFICATION 2 Unit Description 2. All rights reserved. page 6 shows the process diagram for the rectification unit CE 600. Germany 10/2009 This chapter sets out more information on the design of the unit and its components.U. 2 Unit Description 5 .N. Gerätebau.T.1 Process diagram Fig. 2. G. 1 6 Process diagram of rectification unit CE 600 2 Unit Description .10/2009 CONTINUOUS RECTIFICATION I T1 T1 CE 600 Fig. 2. Overview 2 Unit Description 7 . Germany 10/2009 11 10 9 8 7 6 12 5 13 4 Item Name 3 14 2 15 1 16 Fig. G.N. Barsbüttel. Continuous Rectification.10/2009 CE 600 2. Gerätebau.2 17 1 Feed pump 2 Feed tank 3 Control cabinet 4 Top product tank 5 Glass filter pump 6 Pressure gauge 7 Switching valve 8 Phase separation tank 9 Product condenser 10 Switching valve 11 Differential pressure sensor 12 Solvent tank 13 Column 14 Flowmeter for cooling water 15 Evaporator 16 Bottom heat exchanger 17 Bottom product tank CE 600. 2.T.U.2 CONTINUOUS RECTIFICATION Layout All rights reserved. 10). The reflux returns to the unit by way of the column head.3 and Fig. 2.3 Equipment Functions and Components 2. The liquid mixture is pumped into the column from one of the two independent feed tanks (2). The distillate occurring at this point flows into a phase separation tank (8).1 Components for the thermal process Feed connections The Continuous Rectification CE 600 experimentation unit is used to separate homogeneous liquid mixtures by means of rectification on an experimental scale. Fig.10/2009 CE 600 CONTINUOUS RECTIFICATION 2. The tank has level indicator tube on its front.4). Using two electric switching valves (7. The steam passes along a metal tube at the top of the column into the water-cooled product condenser (9). The pressure loss above the column is recorded by a differential pressure sensor (11). Either a packed column or a sieve plate column with eight plates can be used (see Fig. From there. Fig. The evaporator is charged by means of the feed pump (1). A steel tank with a built-in electric heater acts as an evaporator (15) for the liquid mixture. 2.3.3 Sieve plate column One of the columns (13) in which the separation takes place is mounted on top of the evaporator. 2.4 8 Packed column 2 Unit Description . the distillate downstream of the phase separation tank can also be split into reflux and top product with a defined reflux ratio. a tap enables it to be discharged directly into a top product tank (4). 2. 2 Unit Description 9 . The pump is also operated with water from the laboratory supply.5) is used to regulate the flow of water through the pump. 2. Germany 10/2009 18 19 Water connection Fig. Gerätebau.5 Cooling water connection The residue which is enriched in the evaporator during the experiments is called the bottom product. 2.T.N. In doing so. The bottom product can be drained directly into a suitable vessel by way of a tap on the front of the evaporator. 2.10/2009 CE 600 CONTINUOUS RECTIFICATION The cooling water for the product condenser must be supplied from an external source via a laboratory connection (for position of connection see Fig. it passes through the bottom heat exchanger (16). G.5). it can be discharged into one of the bottom product tanks (17). The pump reduces the pressure throughout the system. the bottom heat exchanger can be operated with cooling water from the laboratory connection to cool the bottom product. This can be used to preheat the feed (mixture infeed) with the waste heat of the draining bottom product when the unit is operating in continuous mode. If this feed preheating is not required. The hand valve (item 19 in Fig. The level of vacuum can be read from the pressure gauge (6). All rights reserved. Barsbüttel. A glass filter pump (5) is used to perform experiments with vacuum. Alternatively. 2.U.5). This volumetric flow is regulated by way of the hand valve (18) above the flowmeter (see Fig. The cooling water volumetric flow can be read from the flowmeter (14). All available data can be measured and recorded.10/2009 CE 600 2. page 13). 2. and all control functions can be implemented. by means of the separate program on PC.4.2 CONTINUOUS RECTIFICATION Control cabinet Some switching and monitoring functions can be provided by the electrical control cabinet (3). front view 2 Unit Description . (see chapter 2.6 10 27 Control cabinet. Item Name 20 21 30 22 20 Temperature display T1-T12 with measuring point selector switch 21 Temperature display T13-T16 with measuring point selector switch 22 Controls for the reflux ratio 23 Display for the differential pressure of the column 24 “Low Level” warning lamp (lack of liquid in the evaporator) 25 “Watchdog” warning lamp 26 USB port 27 Master switch 28 Emergency Stop button 29 Controls for the feed pump 30 Controls for the heater 23 29 24 25 26 28 Fig.2.3. 2. Additional control cabinet functions: • “Watchdog” warning lamp (25).N. with: Local: Settings made on control cabinet Auto: Control from PC Digital displays are installed for these unit components and for the differential pressure and the temperatures.10/2009 CE 600 CONTINUOUS RECTIFICATION The following unit components can be operated from the control cabinet: • Heater (30) • Feed pump (29) • Reflux ratio (22) All rights reserved. rear panel 2 Unit Description 11 . Gerätebau. signals failure of the external controller (PC) • “Low Level” warning lamp (24) The evaporator is fitted with a level switch. G. Fig. if the level falls below the minimum (~3L).T.U. Germany 10/2009 The controls listed below are provided for the purpose: • I/O switch • Adjusting knob • Local/Auto selector switch.7 Control cabinet. • On the rear of the control cabinet there are sockets to connect the temperature sensors T4-T11 of the column (see Fig. To prevent overheating. The warning lamp is also activated. Barsbüttel.7). the heater is automatically deactivated. 2. 12 2 Unit Description . • Boot the PC • Load the G. Only after the software has been installed can the USB hardware be connected. laptop or notebook with USB port (see Appendix for minimum requirements).U. No further aids are necessary! After starting.N. along with the CE 600.N. delivered by G.4 Data acquisition program 2.exe” in the folder “Installer”.U.runtime program for PC data acquisition • Driver routines for the “LabJack®” USB converter Installation procedure Note! Connect nothing to the USB port during the installation of the program.1 Installing the program The following is needed for the installation: • An fully operational PC. .N. the installation runs automatically.U. • G.4.T.T. During the course of the installation.10/2009 CE 600 CONTINUOUS RECTIFICATION 2.CE 600 CD-ROM • Start the installation program “Setup.T. . various program components are loaded onto the PC • LabVIEW®.CD-ROM Note! All components necessary to install and run the program are contained on the CD-ROM. The Continuous Rectification CE 600 system diagram then appears on-screen (see Fig.. Germany 10/2009 The program for the CE 600 is selected and started by choosing: Start / All Programs / G. • Reboot the PC after the installation is finished. G..100%) • Feed pump (0.U.4.2 Operating the program All rights reserved.T.100%) 2 Unit Description 13 . Note! The language selected can subsequently be changed at any time on the “Language” menu.N. 2. the language to be used for the program is requested (once only). / CE600 When the software is run for the first time after installation.9). The following elements can also be controlled from the PC: • Heater (T3) • Reflux ratio (0.. 2. Fig..10/2009 CE 600 CONTINUOUS RECTIFICATION • Follow the installation procedure on the screen.8 Language selection It shows the available system data along with the associated measuring point positions. Barsbüttel.U. Gerätebau.N. 2.T. . System diagram One of two modes can be selected: • Manual: The desired (0. If required.10/2009 CE 600 CONTINUOUS RECTIFICATION Fig. 2. It features only the Manual mode. 14 2 Unit Description .. Setpoint values and control parameters are entered on the PC.9 Process diagram. the default set of control parameters can be activated again (therefor click „File“ and „load default values“). The feed pump cannot be controlled automatically.100%) value is directly entered • Auto: The PC functions as a controller. Note regarding Auto mode: The actual set of control parameters will be stored. 2 Unit Description 15 .N. Germany 10/2009 1 Fig. use the "Start/Charts" pulldown menu.T. Click the mouse or press “Enter” to confirm.U.10 “Charts/Time progression” dialog box The axes of the curve view can be scaled. In this dialog box the measured signals are displayed as curves. Measured value files can also be defined and recorded in this dialog box. G. 2. Gerätebau. Additional functions: 5: Enter the time span for the graph. To do this. 2 3 4 5 6 All rights reserved. 6: Start/stop the chronological advance of the curve.10/2009 CE 600 CONTINUOUS RECTIFICATION To access a display of the progression of the signals over time. click on the start or end value and type in the new value using the numeric keypad. Barsbüttel. 2. The measured data field contains a chronological sequence of measured data records. 1: Write the current measured data record to the measured value file once (“single shot”). 3: The green field briefly lights up to indicate each time that measured data records are written to the file. Each series is divided into a header and the measured data field.11 16 “Settings“ dialog box 2 Unit Description . according to the setting in the dialog box detailed below (see Fig. 2: Click this button to start automatic recording. 2. 4: Click the "Settings" button to open another dialog box: 10 11 9 8 12 7 Fig. A measured data record contains the current measured value for each individual measuring point.10/2009 CE 600 CONTINUOUS RECTIFICATION A measured value file can consist of more than one series of measurements.11). 12: This box can be used to enter any comments. either by turning the pointer or by typing the figure in the white field. G.T. The comments are displayed in the measurement series header. 10: A name and a storage location for the measured value file to be created must be entered. Gerätebau. Germany 10/2009 9: The interval for automatic recording of measured data records is defined here (time between recording of two measured data records).U. If the box is ticked. 11: This box may be ticked or unticked. 2 Unit Description 17 . Barsbüttel. a new series of measurements is created in the existing measured value file. the new measured data records are attached to the previous ones in the same measured data field. details of background conditions and so on.N. All rights reserved. 8: The duration of continuous measurement is defined here. If it is unticked. such as the experiment number.10/2009 CE 600 CONTINUOUS RECTIFICATION 7: The number of measured data records to be stored is entered here. 1.6 Shutdown • Shut down the PC • Switch off the unit at the master switch • Shut off the water supply and isolate the unit from the water main • Leave unit to cool • Check the positions of the hand valves. 2.4. reflux unpressurized • Connect the unit to the mains electricity supply • Install the data acquisition and control program on the PC (see chapter 2.10/2009 CE 600 2. page 12) • Plug the unit into the PC For more information and detailed instructions for performing the experiment refer to chapter 5 and chapter 6. 2. page 9). drain all tanks completely 18 2 Unit Description . prevent unintentional leakage of liquids • If the unit is being shut down for a lengthy period of time.5 CONTINUOUS RECTIFICATION Commissioning • Ensure that all hose connections are secure and free from leaks • Connect the cooling water supply and reflux lines (see Fig.5. in particular the safety instructions. G. Select chemicals such that ignition temperatures cannot be reached during operation. WARNING There is a risk of explosion if the wrong chemicals are selected. Germany 10/2009 The experiment instructions.N. 3 Safety 19 .U. Gerätebau. unplug the mains power plug. must be read thoroughly prior to starting up the unit.1 Health hazards WARNING Risk of electric shock when working on the control cabinet Have work on the control cabinet carried out only by a qualified electrician.T. Before commencing an experiment. all participants must have been instructed in the safety aspects and proper handling of the unit. This applies to the single input materials and to mixtures of them. Barsbüttel.10/2009 CE 600 3 CONTINUOUS RECTIFICATION Safety All rights reserved. WARNING Risk of electric shock due to wetness and moisture on the control cabinet Do not allow the control cabinet to get wet. Prior to opening the control cabinet. 3. Drain the heated bottom product only into a heatproof container. WARNING Risk of burns by touching the apparatus. in particular the evaporator. Use only chemicals which do not attack VITON. and wear heat-resistant gloves while doing so.2 Hazards to the unit and its function NOTICE The choice of chemicals for rectification is limited by the resistance of the materials used in the construction of the equipment. Do not touch hot surfaces. 3.10/2009 CE 600 CONTINUOUS RECTIFICATION WARNING Potential health hazard when handling chemicals. PVDF. WARNING Risk of scalding when removing the heated bottom product. Follow the relevant health and safety instructions. particularly with regard to charging and draining the unit. PTFE and stainless steel! 20 3 Safety . the column and the pipes. 2 0. 4.8 0. The proportion of high-boiling constituents in the residual mixture is correspondingly higher. The collected condensate is therefore richer in low-boiling constituents compared with the initial mixture.U. the vapour phase has a different mixture ratio than the liquid phase. Germany 10/2009 Distillation and rectification are thermal processes used to separate or purify liquid mixtures whose constituents are wholly miscible with one another. In distillation/rectification therefore. This curve indicates the mixture ratio of the steam given off by the boiling liquid. wherein the substance A has the molar fraction x1. But substance A now has a different molar fraction y1 in the steam than it does in the liquid mixture AB. 1 0. Gerätebau.4 0.6 0. The more the curve arcs away from the diagonal of the diagram. 4 Theory 21 . we obtain the curve of equilibrium (see Fig. Curves of equilibrium are different for different substance mixtures.6 0.2 0 0 0.T.3 0. vapour arises from it.10/2009 CE 600 CONTINUOUS RECTIFICATION 4 Theory 4.8 Molar fraction x1 of substance A in liquid mixture AB Fig.1 Basic principles Both processes work by the basic operations of evaporating a liquid and then condensing the resulting vapours. When a liquid mixture AB is brought to the boil.4 0. 4.N. Barsbüttel. This fact is the basis of both processes.1). Molar fraction y1 of substance A in vapour AB All rights reserved. G. the greater is the increase in concentration of substance A from liquid to vapour.52 0.1 Example of a curve of equilibrium 1 If we enter the corresponding values for the vapour for all possible mixture ratios of AB in a diagram. Fig. There is also the process in which the condensate is collected in different vessels. schematic In simple distillation. • a condenser to condense the low-boiling component (distillate). Residue • one or more tanks to collect the distillate.1. page 21).10/2009 CE 600 4. all of the distillate is collected. as distillation time passes. Distillation apparatus consists of: Evaporator Condenser • an evaporator to heat the initial mixture and collect the high-boiling component (residue).1. Distillation. a liquid mixture is brought to the boil and the resulting vapour is drawn off and condensed. This condensed liquid is known as the distillate.1 CONTINUOUS RECTIFICATION Distillation In distillation. The remaining mixture is the residue.2 Distillate Distillation does not produce a complete separation of the initial mixture. A vacuum pump downstream of the condenser maintains a vacuum throughout the system. 4. To protect temperature-sensitive substances during distillation. This is known as fractional distillation. This method is known as vacuum distillation. This process is essentially just the same as conventional distillation. It just divides the initial mixture into two mixtures with different concentrations (see chapter 4. 22 4 Theory . their mixtures are distilled in a vacuum where boiling points are lower. known as fractions. All rights reserved.N. Barsbüttel.T. G. 4 Theory 23 .10/2009 CE 600 CONTINUOUS RECTIFICATION There are two basic types of distillation: • Batch distillation (discontinuous. To compensate for the discharge.U. batch-bybatch): The evaporator is charged and the distillation is continued until no more distillate occurs for example. Germany 10/2009 • Continuous distillation: Distillate and residue are continuously discharged. Gerätebau. a corresponding amount of additional initial mixture (feed) is pumped into the evaporator. 10/2009 CE 600 4. This process should be repeated until the required material is satisfactorily enriched.1. 4.5). is forced into contact with the rising vapours on suitable internals for the purposes of material exchange. Instead of all of the distillate collected in the condenser being drawn off straight away. the released vapour is first passed through a vertical tube called the column before it reaches the condenser. x1 Fig. 4. The difference between rectification and distillation is that the rising vapour mixture and returning condensate flow counter to one another. part of it is returned to the column as the so-called reflux. 4.2 CONTINUOUS RECTIFICATION Rectification The result of the separation obtained by distillation is not sufficient in all cases. the collected distillate should be distilled again. The returned condensate now runs down the column and. The high-boiling component condenses first from the rising vapours. The result is an exchange of material and heat between the rising vapours and the falling liquid. at the next level down. Multiple-stage distillation of this type is expensive and energy-intensive. rectification is applied (for a schematic view see Fig. y4 y3 To improve separation. 24 4 Theory . y2 y1 Consequently.3 x2 x3 Equilibrium diagram for multi-stage distillation x4 x5 In rectification.4 and Fig. The process is therefore also known as reverse flow distillation. 2.T. schematic If the column is a sieve plate column (for illustration see Fig. This intensifies the material exchange in the column. 4.4 Rectification. The result is that the liquid flowing back to the bottom of the column is enriched with high-boiling components. page 35). Bottom Bottom product Fig. There is a wide variety of different packing blocks to suit different separation applications. The number of sieve plates in the column is the plate count.8. G.3. The vapours at the top of the column are correspondingly richer in low-boiling components. A common alternative to the sieve plate column is the packed column. ceramics or metal. The purpose of the large number of packing blocks is to provide the material mixture with a large surface area. 4 Theory 25 . Gerätebau. Thus the number of stages in rectification is comparable to the number of series-connected distillation stages. 5. Packing blocks are small. Germany 10/2009 Top Column The resulting condensation heat causes more low-boiling component to evaporate in turn.N. because at the transition from one stage to the next the vapour does not have to be first condensed and then reheated and evaporated.10/2009 CE 600 CONTINUOUS RECTIFICATION Top product Reflux All rights reserved. The contact between the liquid and gaseous phases occurs throughout the packed bed. Barsbüttel. This improves efficiency. page 8 and Fig. Rectification can be understood as being multistage distillation. It is filled with packing. but with just one evaporator and one condenser.U. regularly shaped pieces of plastic. each sieve plate represents one separation stage. 26 4 Theory . The ratio of reflux to top product is called the reflux ratio. At the top of the column. As already described in chapter 2. To be able to characterise and design packed columns despite this. the concept of theoretical transfer units has been devised. In this process. The value range for R is 0 to 100%. page 8.10/2009 CE 600 CONTINUOUS RECTIFICATION The packed column. NTU (Number of Transfer Units) represents a theoretical number of transfer units and HTU (Height of Transfer Unit) is the height of the packed bed of such a unit. Here R is the ratio of the opening time of switching valve 10 to the sum total of the opening times of switching valves 7 and 10. Differing from the usual definition. the switching valves 7 and 10 are alternately opened and closed. the CE 600 unit separates distillate into reflux and top product by cycling two electric switching valves. an adjusted definition is used as the reflux ratio R for this unit.1.3. In this. The reflux ratio v may assume values from zero to infinity. with its homogeneous packed bed. the distillate is divided into one part reflux and one part top product. has no direct plate count. It is an important characteristic value for operation of the unit. G. The entire condensate flows into the top product tank.10/2009 CE 600 CONTINUOUS RECTIFICATION The following examples illustrate this reflux ratio R: • R=100%: Switching valve 10 is permanently open. The condensate flow is divided. schematic representation 27 . Barsbüttel.N. and for the same amount of time. Condenser Column head Reflux Reflux divider Aftercooler Column with internals Evaporator Initial mixture Top product (low-boiling) Column bottom Aftercooler Fig. The entire condensate flows back into the column.U. Germany 10/2009 • R=0%: Switching valve 10 is permanently closed.5 4 Theory Bottom product (high-boiling) Rectification unit. switching valve 7 permanently closed.T. the other is routed to the top product tank. One portion flows back into the column. Gerätebau. switching valve 7 permanently open. • R=50%: Switching valves 10 and 7 are alternately opened and closed. All rights reserved. 4. batch-bybatch): The evaporator is charged and the rectification is continued until no more top product occurs for example. Even mixtures with curves of equilibrium close to the diagram diagonal are separated much more effectively than in single-stage distillation.10/2009 CE 600 CONTINUOUS RECTIFICATION Rectification can also be carried out in two different ways: • Batch rectification (discontinuous. • Continuous rectification: The top and bottom products are continuously discharged. Liquid mixtures can be separated virtually completely by rectification. To compensate for the discharge. a corresponding amount of additional initial mixture (feed) is pumped through the column. 28 4 Theory . G.6 Azeotropic mixture. Barsbüttel. 4 Theory 29 . ethanol/water 60 di ag on al 40 ia gr am 20 D Low-boiling mass fraction in the vapour 80 20 40 60 Low-boiling mass fraction in the liquid Fig. Germany 10/2009 This means that the curve of equilibrium intersects the diagram diagonal.6 Curve of equilibrium of an azeotropic mixture Normal rectification can only separate such mixtures down to their azeotropic point. Azeotropic point 100 95.N. The vapour arising from the mixture has the same composition as the liquid phase. All rights reserved.6 80 100 95.g. Gerätebau.3 CONTINUOUS RECTIFICATION Azeotropic mixtures A special case occurs with regard to many liquid mixtures when they reach a certain concentration.U. e.T. 4. Such mixtures are called azeotropic.10/2009 CE 600 4.1. This substance forms a low-boiling or high-boiling mixture together with one of the components. This means the ancillary cyclohexane circulates around the system. no further enrichment of the lower-boiling component in the condensate is possible. Owing to their different densities. Water and cyclohexane are not miscible. It is intermingled with the product containing approximately 95%m ethanol. and the now lower-boiling water/cyclohexane mixture. Consequently.10/2009 CE 600 CONTINUOUS RECTIFICATION The closer the separation gets to that point. 30 4 Theory . which is enriched in the bottom of the column. the more similar the compositions of the liquid and vapour become. For an ethanol/water mixture for example. Two methods can be applied to obtain a pure component: • Altering the working pressure in the column by vacuum or high-pressure distillation. This likewise enables the azeotropic point to be shifted. The product is separated into the now higher-boiling ethanol.6%m (mass fraction). cyclohexane is a suitable ancillary substance. • Addition of an ancillary substance to the mixture. This process is termed azeotropic rectification. For an ethanol/water mixture for example. they are separated in the phase separation tank. This enables the azeotropic point to be shifted or eliminated in many cases. The lighter cyclohexane floats to the top and is fed back into the column. this concentration is 95. 1 Preparing the unit First run through the commissioning procedure as detailed in chapter 2. page 32): • feed tank • evaporator • top product tank • bottom product tank 5 Experiments .4.1 to Fig. 5. page 18.1. G. Gerätebau. page 6.5. it is useful to be able to obtain a quick estimate of the levels in the various tanks.Preparations. 5. This is why the following tanks have level markers (Fig. instructions for performing 31 . 5. variants.U. Germany 10/2009 The following provides instructions for carrying out rectification with the CE 600 unit. variants.10/2009 CE 600 5 CONTINUOUS RECTIFICATION Experiments . Barsbüttel. This section occasionally refers to CE 600 components without showing the process diagram adjacent to the text.Preparations.T. For clarification. instructions for performing All rights reserved.1 Tank volumes When performing the experiments. 2. 5.1.N. please refer to the process diagram in Fig. 5.2 Top product tank (V) volume Fig.1 Feed tank (VI) volume Fig. 5. 5. instructions for performing .Preparations.4 Evaporator (II) volume 5 Experiments . 5.10/2009 CE 600 32 CONTINUOUS RECTIFICATION Fig.3 Bottom product tank (VIII) volume Fig. variants. • Clean the two flange seals (see Fig. 5.N.5 Column photos 5 Experiments . • Fit the screws. • With the aid of a second person. Barsbüttel. 5.T.6) and coat them on both sides with water (for explanatory notes see below). Fig.1. All rights reserved. variants. carefully fit the replacement column with the flange seals. run through the following steps (see adjacent photos in Fig.1 Replacing the columns To convert between a sieve plate and packed column.1. Store the column carefully. • Reel up and tie the cables in pairs.Preparations. detach and unplug the connectors of the measuring cables for temperature sensors T4 to T11. G.5).U. • Detach the hoses from the column hose couplings. Gerätebau. Germany 10/2009 • Make sure sufficiently. the unit has cooled down • On the rear panel of the control cabinet. 5.10/2009 CE 600 CONTINUOUS RECTIFICATION 5. retaining rings and nuts on the top and bottom column flanges and tighten them evenly. using a cable tie for example. • Unscrew and remove the screws on the top and bottom column flanges.2. push the column head up slightly and remove the column.2 Refitting the columns 5. • With the aid of a second person. instructions for performing 33 . so that the temperature sensors are not bent. • Release the clamp around the column head. This makes removing them more difficult. The following steps must be run through to remove a sieve plate: • Clamp the sieve plate column to the bench • Slacken and remove the flange screws at the desired separation point Fig. Keep to the assignments labelled on the connectors and on the rear panel socket. it is useful to investigate the influence of the number of plates. The adhesion can be reduced by coating the flange seals with water prior to fitting.2. 5. variants. • Unreel the tied-up measuring cables.10/2009 CE 600 CONTINUOUS RECTIFICATION • Clamp around column head.2 Sieve plate column. instructions for performing . Fig.8 and Fig. For the sieve plate column. The following photos in Fig.7 34 Sieve plate column mounting 5 Experiments . Fig. • Connect the hoses to the column by their couplings.Preparations. 5.1. 5. • On the rear panel of the control cabinet.7 shows how the disassembled sieve plate column can be clamped to a bench. The following section explains how individual plates can be removed from the column and reinserted into it. insert and secure the connectors of the measuring cables for temperature sensors T4 to T11. plate removal The flange seals tend to adhere more strongly to the flanges as the service life advances.9 the actions required.6 Flange seal 5. 5. 5. 5.9. Gerätebau.10/2009 CE 600 CONTINUOUS RECTIFICATION • Detach the upper section of the column • Release the temperature sensor mount (1) • Pull back the temperature sensor (2) • Remove the sieve plate (3) • Assemble the distance washer (see Fig.Preparations. item 4). 5.9. Barsbüttel.N. G. retaining rings and nuts. Purpose of the distance washer: Five distance washers are part of the accessories. and tighten the union nut 1 2 • Moisten the O-ring (see Fig.U. Fig.T.8 Photos: Disassembling a sieve plate column 5 Experiments . • Fit the screws. and to avoid damages of the temperature sensor (without distance washer. item 5) and ensure it is firmly seated • Carefully slot the upper section of the column at the correct angle (not twisted) into the bottom section (without tilting it). Germany 10/2009 • Return the temperature sensor (2) to its original position. instructions for performing 35 . replacing the removed sieve plate (3) All rights reserved. follow the above procedure in reverse. 5. The assembled distance washer replaces the removed sieve plate. there is a risk that the temperature sensor between the upper and lower sections of the column may be crashed). variants. in order to get the identical overall height of the column. 2 3 To add a single sieve plate. Tighten the nuts carefully and evenly. a packed column is supplied with insulation. so as to reduce heat loss. 36 5 Experiments .9 Photos: Assembling a sieve plate column The photos illustrate that the space between the flanges is required for removal and fitting of the sieve plates. Consequently. By contrast. 5. variants.Preparations. there is no room for insulation on a sieve plate column.10/2009 CE 600 CONTINUOUS RECTIFICATION 3 4 5 5 5 5 Fig. instructions for performing . 25L capacity. density spindle/areometer.U. for interim storage of the substances and mixing • A shallow cup. measuring cups • Three measuring cups. for removing bottom product from the bottom product tanks. measuring range up to at least 2. Germany 10/2009 5.2.g. All rights reserved. 500ml.5kg • A concentration meter for the material mixture (e. G. Gerätebau.N.2.2 CONTINUOUS RECTIFICATION Accessories for performing experiments To perform the experiments. e. instructions for performing 37 . 2000ml capacity • Two lockable canisters. Barsbüttel.Preparations. e. 5. with upright cylinder) • A thermometer to measure the sample temperature 5 Experiments .1 Tanks. e. variants.g.2 Measuring instruments • A weighing scale. a number of accessories are required in addition to the actual unit and the material mixture under investigation (accessories not included in the scope of delivery).T.g.10/2009 CE 600 5.g. 38 5 Experiments .10/2009 CE 600 5. instructions for performing . This differentiation also determines the basic method of performing the experiment.3 CONTINUOUS RECTIFICATION Experiment variants The unit offers a wide range of options for carrying out experiments under widely varying conditions. or regulated The key difference in terms of operating mode is between discontinuous (batch) and continuous. variants.Preparations. The possible modes include: • Discontinuous (batch) or continuous • Sieve plate column or packed column • Sieve plate column. three different infeed heads selectable • Reduction in the number of plates in the sieve plate column • Operation at ambient pressure or under vacuum • Operation with or without feed preheating • Operation of heater and reflux ratio via fixed values. Gerätebau. page 40 is a variant of the actual process diagram in Fig. Germany 10/2009 5. pipe lines and hoses are colour-coded.Preparations.4 CONTINUOUS RECTIFICATION Experiments .10/2009 CE 600 5. Before performing an experiment. variants.T. The unit components.N.1.operation at ambient pressure Fig. Barsbüttel. 5 Experiments . instructions for performing 39 . 2. All rights reserved.10. page 6. The differences with regard to performing experiments are set out in the following subsections.4.U. the manual stop valves must be set to produce the flow shown during subsequent operation.1 Notes on performing experiments . G.batch mode The batch experiments differ primarily in that the unit is operated at ambient pressure or under vacuum. The meanings of the various colours are indicated by the key. 5. and the flow through the unit for batch experiments at ambient pressure in colour-coded form. variants.Preparations. 5.10 40 Process diagram for a batch experiment at ambient pressure 5 Experiments .10/2009 CE 600 CONTINUOUS RECTIFICATION Closed I Open Closed T1 T1 = Product (two-substance mixture) = Cooling water Fig. instructions for performing . 5. the manual stop valves must be set to produce the flow shown during subsequent operation. Before performing an experiment.10 also specifies the positions of the two small stop valves close to the pressure gauge.12 at the feed connection of the column should be closed so as to avoid unnecessary thermal loading on the hose. 1 Fig.1.U.2 Notes on performing experiments . instructions for performing 41 . 5.11 Ambient pressure circuit 3 If the unit was operated with the stop valve (1) closed. meaning that the temperature level throughout the system would also rise. Such an increased temperature level may result in the destruction of unit components. 5. and represents the flow through the unit for batch experiments under vacuum in colour-coded form.T. 5.10/2009 CE 600 CONTINUOUS RECTIFICATION 2 The process diagram Fig. This equalises the pressure relative to the atmosphere. page 42 is also a variant of the actual process diagram in Fig. They are shown in the adjacent photo Fig. For the same reason. 5 Experiments .11 (items 1 and 2). G. page 6. Fig. feed connection 5.Preparations. All rights reserved. 5. The consequence of the higher pressure would then be a higher boiling point. variants. 2.operation with vacuum Fig. 5.12 Column.N. The stop valve (3) shown in Fig. Gerätebau.4. it is advisable to open the stop valve in order to vent the top product tank (V). Barsbüttel. Germany 10/2009 For operation at ambient pressure it is important to open the manual stop valve (1) underneath the pressure gauge.13. the entire system may be pressurised because of the rising steam pressure. 13 42 Process diagram for a batch experiment under vacuum 5 Experiments . variants. 5.Preparations. instructions for performing .10/2009 CE 600 CONTINUOUS RECTIFICATION Open I Closed Closed T1 T1 = Product (two-substance mixture) = Cooling water = Vacuum lines Fig. When the water valve is opened the flow passes through the glass filter pump from bottom to top.13 specifies the positions of the two small stop valves close to the pressure gauge. Germany 10/2009 The vacuum pump (IX) is executed as a glass filter pump . page 39. G. pressure in the reflux line could result in insufficient vacuum). For the same reason. variants. producing a vacuum.Preparations.14 Glass filter pump 2 When the vacuum pump (IX) is in operation. Fig. the stop valve must be closed for venting of the top product tank (V).1. A higher vacuum is produced by increasing the water flow.15 For operation under vacuum it is important to close the manual stop valve (1) underneath the pressure gauge. 5.N.10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved. Gerätebau.4. 5. 1 Fig.see Fig. 5. 5. 5 Experiments . They are shown in the adjacent photo Fig. 5.15 between the pressure gauge and vacuum pump is opened so that air can be extracted from the system. This prevents the pressure being equalised with the atmospheric pressure. instructions for performing 43 . The vacuum can be influenced by altering the water flow.15 (items 1 and 2).U. the stop valve (2) shown in Fig.14 .T. The process diagram Fig. The water jet effect causes air to be drawn in at the left side pump connection. Stop valves on the pressure gauge As already explained in chapter 5. Take care to have reflux water flow by gravity (connection unpressurized. Barsbüttel. the stop valve at the feed connection of the column should be closed so as to avoid unnecessary thermal loading on the hose. 5. 5. 44 5 Experiments .continuous mode 5.see Fig. page 45. instructions for performing . variants. a variant of the actual process diagram is used to illustrate the flow through the unit . Before performing an experiment.1 Notes on performing experiments Here.5 Experiments .Preparations. the manual stop valves must be set to produce the flow shown during subsequent operation.10/2009 CE 600 CONTINUOUS RECTIFICATION 5.16. too. 5. 16 Process diagram for continuous experiments at ambient pressure. variants. G. example with feed preheating 5 Experiments .10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved.Preparations.U.N.T. Barsbüttel. Germany 10/2009 Closed I Open Open T1 T1 Closed Closed = Product (two-substance mixture) = Cooling water Fig. 5. instructions for performing 45 . Gerätebau. Vent plug Fig. 5.17 For the feed and bottom product tanks it is necessary to unscrew the filler neck drain plugs. To protect the pump. 5. It is not opened until immediately before the feed pump is switched on.18 46 Venting the bottom product tanks (VIII) It must also be ensured that the feed route from the tank into the column is open (see Fig. Attention must also be paid to the following details: 1. These two valves must be closed.1) and (XIV. Vent plug Fig. To enable unhindered charging and draining of those tanks.16).Preparations.17. pumping against closed valves should be avoided. 5.) Bottom heat exchanger circuit: The process diagramFig. page 39. The stop valve at the column feed connection already mentioned initially remains closed. 5.16 also specifies the positions of the two stop valves (XIV. they must be vented. water will flow uncontrolled into the feed tank and the column. the levels in the top product. 5.) Tank breathing: In continuous mode. For the top product tank (V) this is done by opening the top stop valve. instructions for performing . Venting the feed tanks (VI) 2.2).1. The drain plugs next to the filler necks are shown in the photos in Fig. variants. 5 Experiments . If one of the valves is opened during operation.10/2009 CE 600 CONTINUOUS RECTIFICATION The positions of the stop valves close to the pressure gauge apply here as set out in chapter 5. feed and bottom product tanks change.4. variants. Germany 10/2009 To flush through the unit and for test purposes.10/2009 CE 600 CONTINUOUS RECTIFICATION 5. G.T. Where a sieve plate column is installed. This will impair the reproducibility of experiments. water is generally used. The reason is that then.19 To charge the evaporator. Consequently. 5. Water is also a component of the recommended ethanol/water substance mixture. the column may be flooded. The behaviour of the unit will change even before the narrowest cross-section is blocked. 5. it is advisable to connect the hose (1) to the bottom infeed connection of the column (see Fig. the use of water with a hardness < 5°dH is recommended for the cooling and motive water. The quality of the water used is one of the key factors determining the durability of the unit.Preparations. Barsbüttel.2 Pumping from the feed tanks into the evaporator 1 Fig.1 Requirements for the water / water hardness All rights reserved. Charging with sieve plate column 5 Experiments .6. 5. with the larger number of plates.6. the displaced air from below impedes the feed from above. Gerätebau. If it is connected to one of the higher fittings.6 Practical tips 5. the initial mixture is fed into the feed tanks. instructions for performing 47 .19).N. the more deposits and scaling will form in the apparatus and the pipework. The harder the water. For the separation mixture we recommend using distilled water.U. page 60). The bottom heat exchanger (VII) could. if configured so that cooling water flows inside the jacket.Preparations. be used for cooling. there is a risk of scalding. in principle. 48 5 Experiments .3 CONTINUOUS RECTIFICATION Bottom product cooling at the end of an experiment At the end of an experiment there is bottom product at boiling temperature in the evaporator (II). temperature). Use the facility to cool the bottom product (see below). So what is needed is a method of cooling the entire evaporator content. instructions for performing .2. The next day the bottom product is then drained off so as to perform the outstanding measurements (mass. also to save time and enable a second experiment to be conducted on the same day. however. If the bottom product is drained off immediately. variants.6. If there is enough time.10/2009 CE 600 5. density. However. WARNING Risk of scalding when removing the heated bottom product. the unit can be allowed to cool overnight with the bottom product in it.1. the siphon in the evaporator prevents the remaining approximately 6l of bottom product from flowing through (see also chapter 6. Barsbüttel. When the stop valves are switched as shown in Fig.20.T. 5.21.10/2009 CE 600 CONTINUOUS RECTIFICATION Evaporator An elegant solution to the problem is to “shortcircuit” the siphon by a hose. Fig. Hose Fig.U. The hose connects the central outlet of the evaporator with the line from the evaporator to the bottom heat exchanger. 5. Germany 10/2009 The evaporator without hose is shown in Fig.20 Evaporator without hose Fig. All rights reserved. for bottom product cooling at end of experiment 5 Experiments . Gerätebau. G.N. 5. variants. the bottom product bypasses the siphon and flows to the bottom heat exchanger.Preparations. instructions for performing 49 .21 Evaporator with hose. 5.21 shows the evaporator with hose. 5. So the concentration should be checked every time prior to use. It is likely that the concentration of the mixture will change in the course of the experiments.4 CONTINUOUS RECTIFICATION Reuse of input substances It is possible to discard the top and bottom products after each experiment and apply a new mixture of input substances for each new experiment. each new mixture should be composed of a larger initial mix quantity. so as to ensure there is adequate volume for each new experiment. large quantities of input material can be saved by remixing product after performing an experiment.Preparations. The mixture must be reset to the desired concentration as necessary. However. sampling. instructions for performing . variants. spillage when pouring.10/2009 CE 600 5. and so on). This mixture can be reused as the initial mixture for the subsequent experiment. 50 5 Experiments . evaporation. Consequently. The reason is that the more volatile substance evaporates and is lost to a greater extent.6. A certain loss of liquid while the experiment is being performed is inevitable (due to transfers. Here liquid deposits may impair the flow of the top product completely (see also chapter 6. Gerätebau. Here liquid deposits may cause incorrect measurements. It is advisable to detach the hoses in question and drain them before starting a new experiment.N.6. • Hoses between the column and the differential pressure sensor (items 2 and 3 in Fig. though.T. variants.U.2. during cooling after the unit has been in use. page 60. necessary to use hoses with couplings at some points. This may happen at the following points: • Reflux hose (item 1 in Fig. This relates primarily to moving parts (such as the column head) or parts which can be removed and replaced (such as the column). however.5 CONTINUOUS RECTIFICATION Hose lengths 1 Fig. Often.22 2 Reflux hose (red) Most of the lines interconnecting components of the CE 600 unit are pipes. Reflux).10/2009 CE 600 All rights reserved.1. 5. This does not usually entail any negative consequences.Preparations. 5. 5. It also relates to the alternative circuits (three infeeds into the sieve plate column).22). measurement (black) 5 Experiments . arise if liquid collects in the “sack” and affects the process. Barsbüttel. 3 Fig. is not always avoidable. Sagging of hoses. such as flooding of the column. however. If problems persist. G. Germany 10/2009 5. creating a sack effect. it condenses from the system. It is. Problems do. 5. instructions for performing 51 .23 The liquid may occur due to process events.23). the hoses in question should be Hoses for differential pressure shortened to a minimum length. instructions for performing .10/2009 CE 600 52 CONTINUOUS RECTIFICATION 5 Experiments . variants.Preparations. Barsbüttel. because the ratio between the concentration and the density of an ethanol/water mixture is not linear.T. please refer to the process diagram in Fig. Knowledge of the densities of the input substances alone is not sufficient however. For clarification.0kg/L).U. An areometer (measuring range 0.1.1. the sample volume has been specified and the number of possible samples limited. Gerätebau. G.10/2009 CE 600 6 CONTINUOUS RECTIFICATION Experiments .1 Recommended ethanol/water mixture An ethanol/water mixture is recommended for operation of the unit.N. page 6.with ethanol/water mixture 53 . The reason is that the ethanol and water molecules in the mixture influence each other and create additional binding forces (hydrogen bonding).8 to 1. The density was measured in order to determine the concentration. 2. together with an upright cylinder (capacity 500ml) was used to measure the density. 6. 6.1 Material values The concentration of a material mixture can be determined from the mixture’s density. 6 Experiments .with ethanol/water mixture All rights reserved. As a result. for safety reasons. Germany 10/2009 All the experiments on which this section is based were conducted using an ethanol/water mixture. This section occasionally refers to CE 600 components without showing the process diagram adjacent to the text. 10/2009 CE 600 CONTINUOUS RECTIFICATION Consequently, the molecules may take up a smaller overall space, so the volume of the mixture is less than the sum of the individual input substance volumes (volume contraction). In view of that, table values have to be applied across the entire concentration range. The concentration of an ethanol/water mixture is not only dependent on the mixture density, but also the mixture temperature. Tables are frequently to be found which set out the density and concentration for a fixed reference temperature. The reference temperature quoted is often 20°C, sometimes 15°C. Tables for reference temperatures above 20°C are difficult to find. However, extensive material values are provided by the Organisation Internationale de Métrologie Légale (OIML) in the form of “International Alcoholometric Tables” (link: www.oiml.org). They set out the correlations between density and concentration for the reference temperatures -20 to +40°C, for both volumetric and mass fractions. Extracted from those extensive material data listings, the following tables set out the densities, dependent on the ethanol mass fraction, for the temperatures +20 to +30°C. 54 6 Experiments - with ethanol/water mixture 10/2009 CONTINUOUS RECTIFICATION All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 CE 600 Tab. 6.1 For the ethanol/water mixture: Density ρ in kg/m³ as a function of the ethanol mass fraction p and temperature t , 0 ≤ p ≤ 50% , 20 ≤ t ≤ 30°C 6 Experiments - with ethanol/water mixture 55 10/2009 CE 600 CONTINUOUS RECTIFICATION Tab. 6.2 56 For the ethanol/water mixture: Density ρ in kg/m³ as a function of the ethanol mass fraction p and temperature t , 50 ≤ p ≤ 100% , 20 ≤ t ≤ 30°C 6 Experiments - with ethanol/water mixture U..10/2009 CE 600 6. Common concentrations quoted for the ethanol/ water mixture are the ethanol volumetric fraction and mass fraction.2. If possible. the samples should be appropriately temperature-controlled prior to measuring the density.1. Consequently. 6 Experiments . To determine this mass fraction.6.1.2 CONTINUOUS RECTIFICATION Determining concentration by density and temperature The object of density measurement is to determine the concentration of the mixture. under item 5.5. based on a concrete example. All rights reserved. So a more suitable quantity for comparison and balancing purposes is the ethanol mass fraction in the mixture. page 87 ff. the density and temperature of the sample were measured for each concentration calculation.1 can be used.N.3. A comparison of the densities at different temperatures shows that the concentration is substantially dependent on the sample temperature as well as the density.3. No such temperature control was available for the experiments on which this chapter is based. The major influence of small changes in density on the ethanol mass fraction is illustrated in chapter 6. Gerätebau. the tables from chapter 6. Allowance is made for the influence of the temperature by means of linear interpolation (see Evaluation.with ethanol/water mixture 57 . Then the concentration can be read directly from the table with the measured density at the relevant temperature. Germany 10/2009 Any indication of the volumetric fraction is only unambiguously specific in conjunction with the associated reference temperature.T. page 80 ff). G. chapter 6. such as to the reference temperature 20°C. Barsbüttel. temperature 90°C. Result the next morning: The stratification in the insulated evaporator is retained.1. This mixture remains in the evaporator overnight. 2L. 90%m ethanol. the entire evaporator content must be drained off and mixed. Solubility exists across the complete concentration range. When the experiment is complete the top products are collected and fed by way of a feed tank into the evaporator. 58 6 Experiments . with 20%m ethanol. 25°C.with ethanol/water mixture . Nevertheless. There are still major differences in temperature. density and concentration between the mixture at the top and bottom of the evaporator! Result: To determine the density and temperature of the mixture.3 CONTINUOUS RECTIFICATION Mixing behaviour Ethanol and water are mutually soluble. mixing problems are to be expected! Example: At the end of the experiment approximately 8L of mixture remain in the CE 600 evaporator.10/2009 CE 600 6. the reaction of the unit is observed (change in temperatures. 6 Experiments .with ethanol/water mixture 59 . An estimation can be quickly obtained as to whether stable operation is to be expected under specific conditions. a distinction can be made between three different categories of usage: 1. there is a wide variety of experiment variants. using the various control loops 3. Comparative experiments. Spontaneous experiments. This also applies to the ethanol/water mixture. boiling behaviour.). with different background conditions.N. immediately after altering a condition. Germany 10/2009 Depending on the object of the experiment. . The behaviour of the various control loops can be observed.10/2009 CE 600 6. All rights reserved.2 CONTINUOUS RECTIFICATION Definition of background conditions. The limits of the unit are plotted. Automatic mode: Operating the unit in automatic mode is useful when the object of the experiment is to prepare for practical production operations. Gerätebau. with frequently changing conditions 2. recording the influence of a change Re 1.3. While the unit is running. page 38.. G.U. Barsbüttel. The reaction to changes in control parameters can be investigated. differential pressure.. Two different temperature control systems are also possible here. And the associated measured values can be recorded. Spontaneous experiments: Spontaneous experiments rapidly convey a feel for the unit and for the material mixture. experiment series As already described in chapter 5. Re 2. Automatic mode.T. Comparative experiments: The object of comparative experiments is to determine the influence of one change on the measurement results. Another factor is the interaction of thermal and hydraulic influences throughout the system.2. there are advantages in avoiding automatic mode when performing comparative experiments. including in terms of the control engineering. Reproducibility is improved when disturbances to the experiment are minimised.10/2009 CE 600 CONTINUOUS RECTIFICATION Either the temperature T3 in the evaporator or the temperature T12 in the column head can be controlled. attention was paid to covering a large number of different experiment variants at reasonable expense. 6. Instead fixed values should be used for the heater and for the reflux ratio. Consequently. The restricted height means that some infeed heads and supply pressures are limited. 60 6 Experiments . the individual experiments must be reproducible. the CE 600 is not optimised for a specific application. To do this.1 Method of operation of the unit In contrast to large-scale production units. Rather. These instructions primarily relate to comparative experiments.with ethanol/water mixture . Re 3. N. Barsbüttel. Germany 10/2009 • Column differential pressure: The differential pressure is a measure of the boiling intensity and separation efficiency in the column. So at this point the method of operation of the unit for an ethanol/water mixture is depicted: All rights reserved. If the siphon was not installed. changes sometimes do not lead to the intended result. This results in the practical maximum of around 10L. Gerätebau. G. the heater is switched off if the level falls below the minimum. • Liquid level in evaporator (II) in batch experiments: The minimum is given by the switching point of the level switch (at just over 3L). 6 Experiments .10/2009 CE 600 CONTINUOUS RECTIFICATION In spontaneous experiments. • Liquid level in evaporator in continuous experiments: A siphon is installed in the evaporator upstream of the outlet. the evaporator would quickly be completely drained as the flow passes from the evaporator to the bottom product tank (VIII). The maximum is based on preventing flooding of the evaporator. We recommend setting the heater to produce a differential pressure of around 10 to 20mbar. If the pressure exceeds 20mbar the boiling intensity is high.with ethanol/water mixture 61 . the boiling intensity is low and the experiment takes an unnecessarily long time. The interface between the liquid and the steam/air should always remain visible in the level indicator tube.T. If the pressure falls below 10mbar. The volume of steam in the column is then sometimes so great that the downward flow of condensate is too severely impaired.U. For safety reasons. The result is then unstable operation. This difference in height must overcome the pressure difference built up between the column head and the phase separation tank during operation (ambient pressure). the flow from the phase separation tank to the top product tank (V) is not impeded when the valve (XIII) is open (both tanks are at ambient pressure). the siphon restricts the flow from the evaporator to the bottom product tank at ambient pressure.10/2009 CE 600 CONTINUOUS RECTIFICATION The driving force in this is not only the liquid head at the outlet. If the pressure difference is too large the reflux will be impaired. the range for the usable volume is extended during operation in accordance with the prevailing operating pressure. • Reflux: The reflux flows when the valve (XII) is open owing to the difference in height between the phase separation tank (IV) and the column head. In the case of high reflux ratios it is even possible that top product may back-up in the phase separation tank. Conversely.with ethanol/water mixture . In such cases this pressure difference should be reduced. but also the higher operating pressure in the evaporator. 62 6 Experiments . If the level falls below about 6L. such as by reducing the heat output. referred to the ambient pressure in the bottom product tank. or even prevented altogether. This requires careful observation of the evaporator level during operation and regular adjustment by adjusting the position of the stop valve at the evaporator outlet. This means the range for the usable volume at ambient pressure is limited to 6 to 10L. However. 10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved. So CE 600 enables relatively stable operation in vacuum mode during batch experiments.T. fluctuations in ambient conditions and changes during operation of the unit may cause the unit properties to change and so shift the optimum parameter over time. vacuum mode in continuous experiments cannot run permanently stable because the overall system responds too sensitively to fluctuations.U.N. This in turn influences the pressure in the system. minor changes in pressure have a significant influence on the boiling temperature. Regulating the pressure by altering the water flow into the vacuum pump (IX) requires some practice. Gerätebau. However.with ethanol/water mixture 63 . • Production factors. the boiling intensity in the column can be greatly increased. 6 Experiments . Germany 10/2009 • Vacuum mode: During operation. • Infeed heads of the sieve plate column: The choice of infeed to the sieve plate column influences the stability and reproducibility of the experiment. Barsbüttel. Top infeed can result in inadequate stability and uniformity. or may virtually disappear entirely. By changing the pressure a few hundredths of a bar. G. Without practical testing. 64 6 Experiments . there is a severe risk that any unsuitable choice of conditions will only be identified during the actual running of the experiments.with ethanol/water mixture . worksheets. page 50). It is possible to discard the top and bottom products after each experiment and apply a new mixture of input substances for each new experiment. the difficulty is in safeguarding continuous. stable and reproducible operation for all the planned experiments. experiment series When defining the conditions for comparative experiments and experiment series.2. However. In the following chapters two experiment series are presented in which the conditions of the individual experiments are coordinated. for the experiments on which this chapter is based the products were remixed after each experiment (see also chapter 5.2 CONTINUOUS RECTIFICATION Comparative experiments. The experiment reports.6. It is conceivable that a large number of different experiment series could be developed over time.10/2009 CE 600 6. That is why it is advisable to check a planned new series of experiments in advance by means of spontaneous experiments and correct them as necessary. analyses and suchlike detailed in the following relate to this method.4. 6. Gerätebau. . series comprises All rights reserved. The heating power is indicated as a percentage of the maximum 4.3 lists the common conditions applicable to all experiments V1 to V5.3 CONTINUOUS RECTIFICATION Example of a batch experiment series The batch experiment experiments V1 to V5.U. 6.3 . 100 0 Common conditions for batch experiment series 6 Experiments . Condition type Name Symbol/unit Value Volume V in L 10 Ethanol mass fraction 25 Volumetric flow wE in %m · V in L/h 150 Reflux ratio R in % 100 Heating power Pel in % 100 Reflux ratio R in % 100 Heating power Pel in % 20 At Tx = constant.with ethanol/water mixture 65 .T.10/2009 CE 600 6. G. Germany 10/2009 Tab. Reflux ratio R in % sampling Heating power Pel in % Initial mixture Cooling water quantity Start with At T3 ≥ TWarm Continue with Tab.2. in line with the input prompt on the PC.0kW. Reflux ratio R in % 50 operation with Heating power Pel in % 30 At T3 ≥ TEnd Cancel with Reflux ratio R in % 50 Heating power Pel in % 0 After t = 5 min.N. Barsbüttel. 50 and 100% Experiment V3 is described in detail and evaluated by way of example for this experiment series in chapter 6. 6.4 Variable conditions for batch experiment series After performing these five experiments. at end of operation Key: p = atm or p in bar abs. the following comparisons are possible: • Sieve plate column / Packed column • Sieve plate column.with ethanol/water mixture .4. 6.5 atm atm atm R in % 0 0 50 50 50 TWarm in °C 70 50 70 70 70 TEnd in °C 92 75 92 92 92 Column type: Pd. 8 plates / Sieve plate column. Experiment Unit V1 V4 V5 SP-8 SP-8 SP-8 Pd SP-4 atm 0. SP-4 Operation at ambient pressure or vacuum Reflux ratio. Condition type Symbol. V2 V3 Pd: Packed column SP-8: Sieve plate column with 8 plates SP-4: Sieve plate column with 4 plates atm: Atmospheric pressure / Ambient pressure Tab. 4 plates • Vacuum mode / Operation at ambient pressure • Reflux ratios 0. in operation Evaporator temperature. 66 6 Experiments . SP-8.3. after warm-up Evaporator temperature. page 70.10/2009 CE 600 CONTINUOUS RECTIFICATION The “variable” conditions by which experiments V1 to V5 differ are set out in Tab. 5 bar abs.U. an unchanged abort temperature of 92°C would make no sense for the experiment V2 described.5 bar abs. Barsbüttel. after warmup”. In fact. too. at end of operation.T. As the absolute pressure falls the boiling points drop. are selected so that the experiments are roughly comparable for vacuum mode and operation at ambient pressure (temperature gap between reduced heating power after warm-up and attainment of boiling temperature). That is why the numeric values for the abort temperature TEnd are defined here as the mean value of the initial mixture boiling temperature and the boiling temperature of pure water. Then the abort temperature would be greater than the boiling temperature of the highboiling water component (around 81°C at 0. 6 Experiments . Germany 10/2009 It is necessary to adjust the abort condition because the boiling points of the input substances and mixtures are pressure-dependent. referred to the respective pressure.).with ethanol/water mixture 67 . All rights reserved.10/2009 CE 600 CONTINUOUS RECTIFICATION The abort condition with “TEnd = Evaporator temperature. designated in the table as T3 ≥ TEnd requires some explanation.N. G. designated in the tables as TWarm. An identical abort temperature for experiments in vacuum mode and at ambient pressure would make it difficult to compare the experiments. Similarly with regard to the feed-forward condition “Evaporator temperature. That means 92°C in the evaporator cannot be reached at 0. Gerätebau. These temperatures. in B.pr.tank After t = 5 min.tank After feed volume 5L. operation with Start B.2.pr. Continue with 5 min after first reflux.: Bottom product B.pr. in B.4 CONTINUOUS RECTIFICATION Example of a continuous experiment series The continuous experiment series comprises experiments V6 to V8. abort with ------- ---- Reflux ratio R in % 25 Heating power Pel in % 0 Stop feed pump f in % 0 Stop B. sampling Key: Reflux ratio ------- ---- R in % 100 B.pr.10/2009 CE 600 6.tank: Bottom product tank T3: Evaporator temperature Tab.5 68 Common conditions for continuous experiment series 6 Experiments .5 lists the common conditions applicable to all experiments V6 to V8.pr. 6. 6.with ethanol/water mixture . Tab. Condition type Name Symbol/unit Value Initial mixture in the evaporator Volume V in L Ethanol mass fraction wE in %m 25 Initial mixture Volume V in L 10 in the feed tanks Ethanol mass fraction 25 Cooling water quantity Volumetric flow wE in %m · V in L/h 300 Reflux ratio R in % 100 Heating power Pel in % 100 Reflux ratio R in % 100 Heating power Pel in % 25 Reflux ratio R in % 25 Heating power Pel in % 25 Start feed pump f in % 20 9 Start with At T3 ≥ 80°C .pr. All rights reserved. 6. the experiment can of course be prolonged by likewise pumping the remaining 5L feed into the column. For the feed pump. Germany 10/2009 Experiments V6 to V8 are intended for operation at ambient pressure. 6.0kW.U.N.6 Experiment V6 V7 V8 No Yes Yes Bottom Bottom Centre Variable conditions for continuous experiment series Experiment V7 is described in detail and evaluated by way of example for this experiment series in chapter 6.with ethanol/water mixture 69 . 6 Experiments .6. The sieve plate column is used in each. Barsbüttel. Condition type Feed preheating Yes/No Infeed to sieve plate column Centre/Bottom Tab. page 93 ff.T. in line with the input prompt on the PC. the frequency of the applied current is indicated as a percentage of the maximum frequency.4. If required. to enable comparisons with the batch experiments V1 to V3. Gerätebau. G. The abort condition “After feed volume 5L” is a compromise between the time and measurement commitment and the additional expected results.10/2009 CE 600 CONTINUOUS RECTIFICATION The heating power is indicated as a percentage of the maximum 4. The “variable” conditions by which experiments V6 to V8 differ are set out in Tab. with accessories as set out in chapter 5. V3 Experiment V3 originates from the batch experiment series (see also chapter 6. To depict the change over time of the ethanol concentration in the top product 5.3. page 65). 70 6 Experiments . To concentrate the ethanol 2.with ethanol/water mixture . ethanol fraction 25%m • Sieve plate column • Operation at ambient pressure • Cooling water flow 150L/h • Operation at heating power 30%. To check the concentrations by means of mass balances 6.2.3 CONTINUOUS RECTIFICATION Example of a batch experiment. To determine the ethanol concentration in the initial mixture.1 Experiment aims Experiment aims are: 1. page 37. top product and bottom product 4. Conditions for this experiment are: • Initial mixture 10L.3.2 Experimental setup Connected CE 600 unit.10/2009 CE 600 6. Reflux ratio 50% • Rectification aborted (heater off) on reaching evaporator temperature T3 = 92°C 6.3.2. To record the measured value using the data acquisition program (temperature and pressure profiles) 3. e. Initial fixed value 100% 6 Experiments . • Press Reset on the differential pressure display (item 23 in Fig. G. water: 75%m (new addition. • Unit operation by PC. Use measuring cups for this.g. • Set the reflux ratio to 100% initially • Open the condenser water supply and adjust it to about 150L/h • Switch on the heater. Make the settings for data acquisition. page 10 ). page 13).3. ethanol: 25%m. for 12L.6. Check the concentration.6. Germany 10/2009 • The requirement is a canister containing more than 10L of initial mixture.T.U.2. • Transfer the initial mixture from the feed tanks through the column into the evaporator (see chapter 5.1.with ethanol/water mixture 71 . • Transfer the initial mixture from the canister into the two feed tanks (VI). page 39.3 CONTINUOUS RECTIFICATION Performing the experiment • Observe the safety instructions (see chapter 3. • Mix the initial mixture in the canister. • Identify the density and temperature of the initial mixture. with 2885g ethanol and 8655g water). All rights reserved.2. To do so. open the stop valve on the column during pumping. and weigh the content of each cup (net weight of each). page 47). open the measured value file (see chapter 2. Open the manual stop valve underneath the pressure gauge. 2.N. Barsbüttel. page 19) • Prepare the unit as set out in chapter 5. Also weigh the residue in the measuring cup.10/2009 CE 600 6.4. Gerätebau. Fill the feed tanks up to their 5litre marks.4. 72 6 Experiments .6. Determine the mass. • Measure the remaining top product (residue from top product tank together with residue from phase separation tank). Keep the sample (for a later mixed sample). • Cool the bottom product from the evaporator (see also chapter 5. Perform a new measurement as soon as the minimum sample volume has been reached again.Heater from 20 to 30% . reflux begins and the system reaches a state of equilibrium (temperatures constant about 20minutes after first appearance of distillate). density and temperature. • Pour together and intermingle the previous top product samples and measure the total mass. Then changes to operating conditions: .Reflux ratio from 100 to 50% • When the minimum sample volume is reached. page 48). • Abort on reaching T3 = 92°C • 5 minutes after aborting. determine density and temperature. Drain off the cooled bottom product.10/2009 CE 600 CONTINUOUS RECTIFICATION • When evaporator temperature T3 = 70°C is reached. change reflux ratio to 100%. weigh it and mix it in the second canister.3. withdraw the top product from the top product tank (V). Take a sample of the bottom product mixture. Shut off the water supply.with ethanol/water mixture . density and temperature. determine the mass. reduce the heater to the fixed value 20% • Wait for distillate to appear at the phase separation tank (IV). density and temperature. 10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved. Germany 10/2009 • Fill canister with unused initial mixture and with top and bottom product. Based on a minimum recording period of 100 minutes.with ethanol/water mixture 73 . Mix well. the measured values were saved in “. 6 Experiments . would be too extensive to set out at this point. with all measured data records. The measured values for the selected time bands are imported into MS-Excel (see measured value tables Tab. 6. Barsbüttel. G.dat” file format.4 Measured values 6.4.T.N. each with 21 measured values). The MS-Excel Import function is used to import the measured values.2. A measured data record is a snapshot of all the measured values at the given point in time (see also chapter 2. This measured value file contains a chronological sequence of measured data records. this produces more than 4200 measured values (two measured data records per minute.U. page 13).1 Measurement data from the data acquisition program (experiment aim 2) Using the data acquisition program.4. 6.3.7 to Tab.3. This provides a new initial mixture for the next experiment. 6. Consequently. For this experiment an interval of 30 seconds was selected (representing the time between recording of two measured data records). A tabular representation of the complete measured value file.9). Gerätebau. a selection was made to depict the most informative time bands. this enables the start and end of the actual experiment (here 14:30 and 15:06 hours) to be determined from the measured value tables. fixed values were programmed on PC rather than using the software controllers. In the experiment described here.10/2009 CE 600 CONTINUOUS RECTIFICATION The selected time bands are: • Column start-up until production of the first distillate • Start of rectification under operating conditions • End of rectification under operating conditions Alongside the differential pressure P1 and the temperatures T1 to T16.5.with ethanol/water mixture . Using the defined operating conditions (heater Y1=25% and reflux ratio Y2=50%).1. page 78.3. these measured value tables also contain the three control variables Y1 to Y3. 74 6 Experiments . The differential pressure and selected temperatures are presented graphically in chapter 6. 7 80.0 25.8 22.9 86. measured values at column start-up 75 .4 15.T.0 25.5 79.0 25.1 1.9 14.9 22.0 25.2 87.5 23.9 22.6 24.2 15.0 24.9 14.8 80.3 79.0 25.0 25.5 23.5 76.7 24.0 25.3 25.0 82.5 6.9 22.8 78.7 80.3 22.0 25.9 75.8 22.8 14.4 24.4 84.0 0.2 24.1 80.7 78.2 25.9 26.2 79.0 0.4 23.5 22.9 22.1 25.8 24.1 81.0 24.1 0.0 24.3 80.9 14.8 22.0 25.3 24.6 22.7 59.0 23.6 22.4 23.6 22.9 26.9 22.4 82.6 78.9 14.9 24.0 24.6 22.2 15.4 79.2 15.0 10.2 87.1 25.9 23.8 79.9 14.3 87.0 25.1 25.7 24.7 25.with ethanol/water mixture 82.9 79.8 79.0 24.0 24.3 25.1 60.5 78.0 25.9 23.0 25.6 14.2 25.8 34.0 24.2 83.2 79.5 31.6 24.6 80.0 24.5 23.4 23.8 14.4 78.1 7.0 75.4 23.9 81.3 82.5 23.4 26.5 23.5 87.9 24.9 14.8 4.3 79.7 28.0 24.0 25.0 25.9 14.0 -0.4 t hh:mm:ss All rights reserved.9 9.5 23.3 57.9 25.0 0.6 22.5 79.5 81.7 78.1 24.0 0.9 22.0 0.5 23.7 25.2 15.4 79.9 14.2 25.9 25.0 80.9 25.1 78.6 22.4 23.0 24.4 80.0 25.0 79.0 25.2 15.6 23.6 79.3 24.5 78.0 24.2 78.2 25.9 86.1 76.0 25.8 14.9 14.6 22.4 24.3 83.0 25.4 79.2 82.0 79.7 14.3 15.9 23.2 25.0 24.0 15.4 24.9 23.5 79.0 24.2 32.0 24.3 79.U.2 25.6 22.6 22.1 T1 °C 13:31:17 23.2 25.0 52.0 24.0 23.4 15.0 24.0 25.0 31.4 79.0 66.7 33.2 34.3 70.1 8.2 25.1 25.4 23.5 23.2 25.3 77.9 24.0 24.6 22. 6.7 24.1 24.1 0.0 23.4 33.0 25.2 72.5 77.3 85.4 62.4 24.0 24. Y3: Controller Outputs for heater.0 83.8 74.2 25.6 87.1 24.9 80.9 22.6 24.5 24.6 80.4 79.2 80.5 24.8 14.6 22.4 23.5 24.5 24.4 23.4 85.2 79.2 80.3 15.0 25.4 87.0 25.2 -0.3 78.0 25.0 24.6 22.2 79.7 14.2 25.4 23.0 25.4 23.8 87.9 85.2 15.7 22.4 80. Germany 10/2009 10/2009 CONTINUOUS RECTIFICATION V3.0 24.1 -0.6 22.9 85.3 16.5 87.0 25.9 22.2 15.3 24.5 24.3 1.1 25.2 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CE 600 22.2 25.5 23.5 79.7 78.8 25.2 87.7 24.1 17.3 77.9 78.0 25.0 25.9 22.0 24.9 23.1 79.2 15.8 8.2 25.0 22.8 79.1 82.0 25. Gerätebau.2 80.3 62.0 79.4 77.6 22.6 56.4 80.2 15.4 78.2 56.3 15.4 26.2 81.6 22.5 22.0 1.0 25.4 24.8 22.0 25.3 82.9 78.4 80.9 22.8 14.3 24.5 81.8 14.3 80.7 78.4 23.1 0.9 14.0 25.9 14.0 25.4 23.4 87.0 25.0 25.4 15.6 22.0 24.0 25.9 25.6 22.9 24.5 79.0 25.9 23.5 23.0 23.0 82.4 71.3 77.4 23.5 79.5 23.0 33.2 25.1 -0.2 25.8 83.4 23.6 25.3 79.1 22.5 15.0 24.5 23.1 25.8 22.9 80.8 22.5 22.9 22.2 15.2 79.1 25.3 17.0 25.T4 °C T5 °C T6 °C T7 °C T8 °C T9 °C T10 °C T11 °C T12 °C T13 °C T14 °C T15 °C T16 °C Tab.7 14.0 25.3 10.9 14.1 25.2 0.1 25.8 61.0 24.7 14.6 79.6 22.1 25.0 25.1 64.3 15.5 75.9 15.2 78.1 63.2 15.9 14.6 26.4 8.4 23.5 23.3 79.9 25.6 43.9 82.1 25.6 23.0 24.4 79.0 23.6 79.7 72.6 22.7 14.4 23.5 22.4 24.7 17.2 76.3 80.7 22.9 25.5 87.4 78.5 23.8 14.0 79.2 86. 23.5 67. Barsbüttel.2 79.5 82.0 23.2 5.8 22.3 15.8 22.6 83.4 79.7 14.6 9.6 10.0 81. Y2.9 22.2 87.6 30.6 78.9 22.0 9.9 78.1 59.3 15.1 16.9 22.1 25.5 32.2 15.9 14.2 87.4 34.6 35.6 22.2 81.9 22.2 0.6 22.6 77.5 81.6 22.8 22.0 24.8 22. Reflux ratio.6 87. frequency of pump drive.3 80.1 25.8 22.2 22.9 22.7 78.1 78.7 14.4 79. R Y3.6 14.7 79.9 23.N.8 61.0 25.8 86.5 87.0 25.9 14.1 80.8 87.8 25.7 79.7 78.7 14.5 79.8 22.5 25.8 24.5 25.9 22.1 79.8 72.4 33.0 68.2 87.2 24.1 15. Y1.1 25.0 24.7 14.5 23.7 58.8 83.4 23.6 22.9 74.0 78.3 80.4 24.9 22.4 81.6 22.5 22.7 81.8 14.3 79.0 25.4 78.7 81.9 3.4 23.9 23.2 79.8 80.2 25. Pel Y2.9 25.3 25.6 22. f mbar % % % -0.0 24.7 84.2 15.8 24.9 81.9 25.9 79.2 25.4 23.0 78.3 65.9 24.6 77.3 79.7 78.9 69.3 15.2 79.7 37.4 5.9 74.4 81.4 33.2 15.7 82.6 22.6 24.0 24.0 25.4 15.0 80.4 23.5 23.6 22.6 80.0 24.2 25.1 7.2 71.4 87.7 14.5 77.3 82.1 62.3 87.0 25.1 15.2 15.1 26.9 24.9 14.9 79. G.8 14.9 86.9 9.9 25.1 79.6 86.6 22.7 0 P1 Y1.6 83.0 24.8 23.9 22.6 22.5 79.6 2.6 77.1 25.2 70.1 -0.7 78.7 23.8 14.1 80.2 25.6 77.2 25.0 Temperatures and differential pressure according to flow diagramm / system diagram.0 73.9 T3 °C 13:55:47 13:56:17 13:56:47 13:57:17 13:57:47 13:58:17 13:58:47 13:59:17 13:59:47 14:00:17 14:00:47 14:01:17 14:01:47 14:02:17 14:02:47 14:03:17 14:03:47 14:04:17 14:04:47 14:05:17 14:05:47 14:06:17 14:06:47 14:07:17 14:07:47 14:08:17 14:08:47 14:09:17 14:09:47 14:10:17 14:10:47 14:11:17 14:11:47 14:12:17 14:12:47 14:13:17 14:13:47 14:14:17 14:14:47 T2 °C -0.2 73.1 87.2 15.6 22.9 25.4 24.0 25.0 25.8 82.7 2.5 79.1 0.3 81.7 6 Experiments .9 24.8 84.8 25.6 22.0 25.1 25.0 25.9 22.6 22.3 15.1 79.7 14.0 84.4 15.2 65.8 25.5 79.9 24.9 36.4 81.9 22.0 25.5 22.4 23.9 24. 6 80.3 25.6 14.7 14.3 13.7 14:28:47 14:29:17 14:29:47 14:30:17 14:30:47 14:31:17 14:31:47 14:32:17 14:32:47 14:33:17 14:33:47 14:34:17 14:34:47 14:35:17 14:35:47 14:36:17 14:36:47 14:37:17 14:37:47 14:38:17 14:38:47 14:39:17 14:39:47 14:40:17 14:40:47 14:41:17 14:41:47 14:42:17 14:42:47 14:43:17 14:43:47 14:44:17 14:44:47 14:45:17 14:45:47 14:46:17 14:46:47 14:47:17 76 23.8 80.0 23.5 88.2 87. T1 °C t hh:mm:ss 10/2009 CONTINUOUS RECTIFICATION V3.0 23.6 14.5 80.8 83.7 23.7 22.6 22.9 84.8 86.1 23.1 89.1 28.3 80.7 83.9 84.4 83.1 23.2 23.7 14.5 81.7 14.1 23.1 89.4 80.8 80.3 81.3 14.0 80.0 88.6 83.3 82.9 88.9 88.5 87.5 88.7 23.0 87.4 89.3 80.5 27.6 22.7 23.1 23.0 81.0 23.8 81.8 14.7 22.4 85.0 T3 °C 86.8 82.6 19.2 27.5 81.0 80.6 23.0 89.6 22.9 14.1 80.3 20.6 23.7 14.1 86.9 86.9 14.7 23.4 20.2 20.7 14.9 14.5 88.8 14.22.9 26.7 80.8 88.4 84.0 20.3 88.3 88.8 81.4 14.6 22.6 86.3 80.4 86.9 89.3 80.6 22.6 83.5 85.3 81.1 89.0 80. measured values at start of rectification 6 Experiments .5 14.5 87.4 T10 °C 79.8 22.7 14.3 83.6 22.7 T15 °C 17.8 87.6 23.3 81.8 83.2 86.7 14.7 14.8 86.1 88.9 80.6 87.6 22.0 88.0 87.8 14.9 80.2 14.7 79.8 23.5 80.0 25.7 23.4 80.9 80.0 89.2 85.7 14.8 22.8 80.2 80.8 79.6 87.6 80.with ethanol/water mixture .9 80.1 23.5 87.6 87.9 87.3 25.6 84.7 23.6 22.7 22.1 85.2 81.7 23.1 23.1 23.9 80.7 14.8 89.3 83.9 89.6 22.1 25.7 23.6 25.4 14.0 85.3 81.3 80.3 80.6 22.9 87.4 80.9 81.4 26.0 T9 °C 79.1 23.4 86.1 23.4 20.9 87.4 80.6 22.9 83.4 88.2 80.8 13.1 23.6 83.7 89.9 28.0 89.6 22.2 80.0 13.8 23.6 14.1 80.3 89.0 23.3 88.7 23.8 14.0 23.5 81.7 80.5 22.4 89.8 85.8 27.7 23.6 89.9 83.0 82.2 20.8 89. R Y3.7 27.7 83.5 81.7 14.2 81. 6.0 80.7 14.5 17.9 80.6 80.4 80.2 20.7 23.1 81.4 79.3 80.6 25. Y3: Controller Outputs for heater.7 81.0 14.1 81.2 80.6 22.6 86.4 20.6 80.7 19.7 14.2 85.5 80.4 20.4 87.2 20.6 86.6 23.4 20.9 89.5 13.6 80.0 81.8 80.0 88.7 85.3 25.2 81.7 14.1 23.8 88.8 88.5 88.2 81.3 80.9 81.3 88.5 81.8 14.0 25.3 20.5 83.7 81.0 80.0 88.1 20.8 79.6 81.6 25.7 79.1 80.5 87.5 14.5 89.6 80.3 14.3 88.5 88.4 81.3 80.1 85.2 T8 °C 80.0 80.7 88.8 80.5 85.6 T7 °C 80.0 83.5 87.8 14. Reflux ratio.9 89.0 80.6 80.3 80.7 27.0 20 20 20 20 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 100 100 100 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 T16 P1 Y1.7 23.7 82.0 88.1 23.0 79.1 88.1 23.6 22.5 17.7 23.2 81.4 86.7 14.6 80.1 23.8 85.4 81.0 14.6 22.3 T6 °C 80.2 84.2 81.6 22.5 86.1 T11 °C T13 °C 25.2 83.5 87.5 86.6 22.6 80.2 25.0 83.6 22.8 87.9 88.5 79.0 81.9 89.5 26.7 23. Y1.1 85.6 83.2 80.2 20.1 88.6 80.4 80.0 82.4 81.9 80.7 87.5 88.6 80.5 79.6 80.7 23.5 82.6 25.3 88.6 22.6 80.2 84.1 23.0 81.3 89.7 80.2 81.7 22.6 23.2 28.2 81.8 23.6 23.9 88.0 81.2 20.6 16.2 20.1 20.1 23.4 88.4 88.5 89.8 88.1 23.3 85.5 14.9 83.2 28.6 14.5 88.6 23. Pel Y2.3 82.5 88.7 23.8 87.1 25.3 88.1 23.0 85.1 85.0 88.5 85.0 27.2 80.3 26.8 14.1 80.6 89.9 81.4 87.3 80.8 88.1 T14 °C 14.7 23.8 27.6 83.9 80.1 28.6 22.7 79.9 87.2 80.7 14.0 88.2 23.7 87.6 83.8 88.7 23. f °C mbar % % % CE 600 Tab.3 T12 °C 79.4 14.5 80.9 86.1 87.7 14.7 22.8 87.9 81.1 88.7 80.5 88.0 14.2 14.4 80.6 22.7 22.1 23.5 83.2 20.3 20.3 80.6 86.0 28.6 84.6 22.6 88.8 86.5 13.9 14.1 23.5 88.1 84.0 14.5 88.1 23.7 80.6 88.1 89.5 87.3 84.7 23.7 14.9 T5 °C 82. Y2.2 80.2 81.6 85.2 16.2 80.8 80.7 88.2 14.2 82.0 23.8 23.2 15.7 14.1 80.3 28.3 88.6 23.1 80.1 23.9 90.5 88.7 14.3 89.4 81.1 88.0 23.9 86.0 14.5 27.4 87.1 23.6 22.1 23.7 22.6 22.1 28.4 14.7 81.8 85.0 87.9 86.2 20.9 88.7 23.0 23.3 80.8 79.5 88.7 87.0 81.7 23.2 87.1 86.5 80.1 23.2 81.5 80.8 79.2 87.8 88.1 T4 °C 85.4 19.7 79.7 23.6 14.1 84.9 83.2 89.7 14.8 85.4 87.5 88.0 13.6 80.0 86.7 80.3 80.4 84.6 80.9 87.5 88.6 22.6 14.7 82.8 86.2 80.6 17.4 20.5 20.4 80.2 14.0 88.2 20.1 23.2 80.0 28.1 88.6 80.1 85.5 25.2 13.6 14.9 81.1 23.4 79.7 23.5 15.8 Temperatures and differential pressure according to flow diagramm / system diagram.7 89. frequency of pump drive.0 27.8 88.1 80.6 80.5 85.0 20.1 88.0 81.3 80.8 81.7 T2 °C 88.6 80.5 87.9 81.2 87.2 20.2 28.3 86.5 80.7 79.7 85.5 88.0 88.2 84.4 88.8 23.2 20.4 14.6 14.6 14.1 20.3 85.2 20.5 80.2 20.8 14.8 20.8 14.6 14.3 19.3 25.7 23.5 15.9 80.6 22.5 81.7 22.7 81.7 80.1 80.5 89.7 23. 90,8 90,9 90,9 89,3 83,3 82,5 82,2 81,8 81,5 81,5 81,2 80,8 79,6 79,0 78,1 77,1 76,5 75,7 75,0 74,4 73,7 73,2 72,7 71,8 71,2 70,8 70,5 70,1 69,6 68,8 68,7 68,3 67,5 67,2 66,4 66,3 65,6 65,6 90,5 90,4 90,4 84,3 82,3 82,0 81,7 81,4 81,2 81,2 80,8 80,1 79,2 78,4 77,4 76,8 76,0 75,0 74,5 73,7 73,2 72,3 71,6 70,9 70,2 69,6 69,0 68,2 67,4 67,0 66,4 65,7 65,3 64,6 64,0 63,4 62,9 62,3 T6 °C 88,9 88,8 88,8 82,8 81,7 81,3 81,1 80,9 80,8 80,6 80,2 79,0 78,1 77,2 76,5 75,7 75,1 74,2 73,4 72,5 72,0 71,1 70,6 69,9 69,4 68,6 68,0 67,4 66,9 66,1 65,6 64,8 64,2 63,7 63,1 62,5 61,9 61,3 T7 °C 86,5 86,6 86,6 82,6 81,8 81,6 81,2 81,4 81,1 80,6 80,3 78,9 77,9 77,0 76,2 75,5 74,8 74,0 72,8 72,3 71,6 71,0 70,2 69,7 69,1 68,5 67,8 67,2 66,5 65,9 65,4 64,7 64,2 63,6 63,1 62,4 61,9 61,3 T8 °C 83,4 83,5 84,0 82,1 81,7 81,5 81,4 80,9 80,6 80,0 79,5 78,2 77,1 76,3 75,5 74,9 74,4 73,7 71,9 71,9 71,4 70,7 70,2 69,3 68,8 67,9 67,3 66,7 66,1 65,5 64,9 64,3 63,5 63,1 62,5 61,9 61,5 60,8 T9 °C 82,1 82,0 82,0 81,7 81,4 81,2 80,4 80,2 79,9 79,2 78,4 77,9 76,5 75,4 74,9 74,2 73,5 72,7 70,0 70,6 70,1 69,4 68,8 68,3 67,6 66,9 66,2 65,6 65,0 64,5 63,9 63,3 62,7 62,2 61,7 61,1 60,6 60,1 T10 °C 81,7 81,9 81,7 81,4 81,1 80,5 80,3 79,8 79,5 78,4 77,9 76,8 75,6 74,8 74,2 73,4 72,7 71,8 66,3 69,5 69,3 68,8 68,1 67,5 66,9 66,4 65,8 65,3 64,7 64,2 63,7 63,1 62,7 62,2 61,6 61,2 60,6 60,1 T11 °C 81,6 81,6 81,4 81,2 80,8 80,2 80,0 79,5 78,6 77,9 77,1 76,2 75,3 74,5 73,8 72,9 72,1 71,4 70,5 69,9 69,1 68,6 67,7 67,2 66,4 65,8 65,3 64,6 64,1 63,4 63,0 62,3 62,0 61,3 60,9 60,4 60,0 59,4 T12 °C 28,0 28,1 28,1 28,1 27,9 27,7 27,8 27,8 27,6 27,6 27,6 27,5 27,2 27,2 27,2 27,2 27,2 27,2 27,4 27,2 27,2 27,2 27,1 27,1 27,0 27,0 27,0 27,0 27,0 26,9 26,9 26,9 26,9 26,8 26,9 26,9 26,7 26,8 T13 °C 23,2 23,1 23,2 23,2 23,1 23,2 23,1 23,2 23,2 23,2 23,3 23,2 23,2 23,2 23,2 23,3 23,2 23,2 23,3 23,2 23,1 23,2 23,3 23,2 23,2 23,2 23,2 23,3 23,2 23,3 23,2 23,2 23,2 23,3 23,2 23,2 23,2 23,2 T14 °C 14,9 14,7 14,9 14,9 14,8 14,9 14,8 14,8 14,6 14,8 14,8 14,6 14,5 14,6 14,5 14,6 14,6 14,6 14,7 14,6 14,8 14,7 14,9 14,8 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 14,9 15,1 T15 °C T16 °C Tab. 6.9 6 Experiments - with ethanol/water mixture 100 30 30 30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 100 50 50 50 50 50 50 50 50 50 50 50 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P1 Y1, Pel Y2, R Y3, f mbar % % % CE 600 Temperatures and differential pressure according to flow diagramm / system diagram. Y1, Y2, Y3: Controller Outputs for heater, Reflux ratio, frequency of pump drive. 91,0 91,3 91,2 90,2 83,4 82,7 82,3 82,0 81,7 81,3 81,3 81,0 80,3 80,1 79,8 79,3 79,3 79,3 79,2 78,8 78,5 78,5 78,2 78,3 78,1 77,7 77,6 76,6 77,3 77,1 76,4 77,0 76,8 76,8 76,5 76,1 76,4 75,2 T5 °C 0,0 92,0 92,0 92,2 92,1 92,1 92,1 92,1 92,1 92,2 92,1 92,1 92,0 92,0 91,9 91,9 91,8 91,9 91,8 91,8 91,8 91,8 91,7 91,7 91,7 91,6 91,5 91,6 91,4 91,4 91,4 91,3 91,3 91,2 91,1 91,0 91,1 91,0 91,0 T4 °C 16:30:47 23,3 23,9 58,5 29,2 24,8 26,7 29,4 30,4 30,8 30,9 31,0 30,8 24,5 22,2 22,0 20,5 23,8 23,8 23,9 23,9 23,8 23,7 23,9 23,8 23,8 23,8 23,8 23,7 23,9 24,0 23,9 23,9 24,0 24,0 23,9 23,8 24,0 23,7 24,0 23,8 24,0 24,0 24,0 23,8 23,9 23,9 23,9 23,9 23,9 23,9 23,9 23,9 23,8 24,0 T3 °C 13,8 13,4 13,1 10,1 9,2 6,8 4,9 3,8 2,7 1,8 0,1 -0,1 -0,1 -0,1 0,1 -0,1 0,0 0,0 0,0 0,1 0,0 -0,1 -0,1 -0,1 0,0 0,0 -0,1 -0,1 0,0 0,1 -0,1 -0,2 0,1 0,0 -0,1 -0,1 0,0 0,0 22,6 22,7 22,6 22,6 22,6 22,6 22,8 22,7 22,8 22,6 22,6 22,6 22,7 22,9 22,6 22,6 22,6 22,6 22,6 22,6 22,6 22,6 22,6 22,6 22,7 22,6 22,6 22,7 22,7 22,7 22,6 22,7 22,8 22,7 22,6 22,6 22,6 22,7 15:05:47 15:06:17 15:06:47 15:07:17 15:07:47 15:08:17 15:08:47 15:09:17 15:09:47 15:10:17 15:10:47 15:11:17 15:11:47 15:12:17 15:12:47 15:13:17 15:13:47 15:14:17 15:14:47 15:15:17 15:15:47 15:16:17 15:16:47 15:17:17 15:17:47 15:18:17 15:18:47 15:19:17 15:19:47 15:20:17 15:20:47 15:21:17 15:21:47 15:22:17 15:22:47 15:23:17 15:23:47 15:24:17 T2 °C 20,3 20,3 20,2 17,4 16,4 16,0 15,6 15,5 15,4 15,3 15,3 15,2 15,3 15,2 15,2 15,2 15,2 15,2 15,3 15,2 15,3 15,3 15,5 15,2 15,5 15,5 15,5 15,5 15,5 15,5 15,5 15,5 15,5 15,5 15,5 15,2 15,5 15,6 T1 °C t hh:mm:ss All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 10/2009 CONTINUOUS RECTIFICATION V3, measured values at end of rectification 77 10/2009 CE 600 6.3.4.2 CONTINUOUS RECTIFICATION Self-recorded measured values (without PC assistance) The self-recorded measured values are primarily the masses, densities and temperatures of the various mixtures/products. In the course of the experiment they were entered by hand on the “Batch worksheet” (see Tab. 7.1, page 117). These measured values are presented, together with the evaluation, in chapter 6.3.5.2, Tab. 6.10, page 81. 6.3.5 Evaluation 6.3.5.1 Presentation of automatically recorded measurement data (experiment aim 2) 90 15 80 13 70 11 60 9 50 7 40 5 30 3 20 1 10 13:55 13:57 13:59 14:01 14:03 14:05 14:07 14:09 14:11 14:13 Time T3, Evaporator temperature T6, Plate 3 temperature T10, Plate 7 temperature P1, Column pressure loss Fig. 6.1 78 -1 14:15 Differential pressure in mbar Temperature in °C The bases of the following diagrams are the measured value tables Tab. 6.7, page 75 to Tab. 6.9 . Please note that the diagrams have differing temperature and pressure ranges. T4, Plate 1 temperature T8, Plate 5 temperature T12, Top temperature V3, Temperature and pressure profile at column start-up 6 Experiments - with ethanol/water mixture 10/2009 Temperature in °C Differential pressure in mbar CONTINUOUS RECTIFICATION Time T3, Evaporator temperature T6, Plate 3 temperature T10, Plate 7 temperature P1, Column pressure loss V3, Temperature and pressure profile at start of rectification Differential pressure in mbar Fig. 6.2 T4, Plate 1 temperature T8, Plate 5 temperature T12, Top temperature Temperature in °C All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 CE 600 Time T3, Evaporator temperature T6, Plate 3 temperature T10, Plate 7 temperature P1, Column pressure loss Fig. 6.3 T4, Plate 1 temperature T8, Plate 5 temperature T12, Top temperature V3, Temperature and pressure profile at end of rectification 6 Experiments - with ethanol/water mixture 79 The “residue” is thus the mass of the mixture remaining in the measuring cup.2 CONTINUOUS RECTIFICATION Evaluation of self-recorded measured values The following Tab.To determine the ethanol concentrations: For all the samples. The procedure is explained here in respect of the first sample (mixture at start of experiment) by way of example: The measured values of the first top product sample are: Total density ρM = 962 kg/m³ at mixture temperature TM = 22. In determining the total mixture mass at the start of the experiment.10/2009 CE 600 6.must be taken into account.5.here 8. the total volume of 10. the ethanol mass fraction E wE was determined from the density and temperature by means of linear interpolation.with ethanol/water mixture . the “residue” .0L is reached before the measuring cup is completely empty.10. This “residue” results from the fact that when transferring from the last measuring cup into the feed tank. Re experiment aim 3 . 80 6 Experiments .8°C (index M for measured value). 6. page 81 presents the measured masses.0g . densities and temperatures. The individual mixture masses at the start and end of the experiment have been added together. together with the total masses and concentrations calculated from them.3. Evap Measurement Start. Evap ----- 22.836 9. Germany 10/2009 Clock Mass Density net Temperature g °C Level Comments Mass Mass fraction in Evap net Ethanol. 2. Fill feed tank.0 ----- 82.: Top product..832 ----- ----- 83.pr.3 ----- End.6 15:06 T.5 1942.pr. Barsbüttel.pr.0 2046.pr.5 Key: T.: Bottom product.0 22.0 15. Evap: Evaporator Tab. mixture.0 23. 429.0 1392.962 10.0 ----- 83.pr.0 0. from Evap. Self-recorded measured values. G.5 24.7 0. T.5 1930.T.N. Gerätebau. Individual masses in g 2022.pr.6 ----- 22.0 1904.825 9.9 14:52 T. 1. 6.0g residue. 430.8 0.832 9..5 22.1 0..pr.. with evaluation CONTINUOUS RECTIFICATION Product/measurement no.8 0. B.0 1953. B.. B.0 1788..0 1932.8 0. Individual masses in g 1945.0 9695. 3. when 10L reached) End.5 458.10 V3.with ethanol/water mixture Measurement 81 .5 22. Evaluation 10/2009 CE 600 6 Experiments . mixture ----- End.U. wE kg/L L g %m 13:15 Start.3 ----- 85.974 ----- 8219.0 (-8. 370.8 14:41 T.All rights reserved.pr. ρ23 = ρ(23%m.51 – 963.8°C) the value 961. The value wE being sought is obtained by linear interpolation with the aid of ρ23 and ρ24 as per: ρ 23 – ρ M w E = 23 + ----------------------.11 – 961. 22. 82 6 Experiments .51 kg/m³ ρB = ρ(23%m. for ρ24 = ρ(24%m.75 %m 963.8%m.01 + --------------------------------------. 22°C) = 963.8°C) is produced by linear interpolation as: 23°C – T 23°C – 22°C M . wE cannot be read directly from Tab. 8°C 23°C – 22°C ρ 23 = 963. The four ρ values for measured value 962kg/m³ belonging to the next highest and next lowest integer values wE and T can be read however: ρA = ρ(23%m.63 kg/m³ is obtained.⋅ ( 24 – 23 ) ρ 23 – ρ 24 963. page 55 because there ρ is listed only for integer wE and integer T. this produces the desired ethanol mass fraction of wE = 23. 22.05 kg/m³ ρD = ρ(24%m. 22°C) = 962. 23°C) = 963.⋅ ( 963.11 – 962 w E = 23 + ----------------------------------------.10/2009 CE 600 CONTINUOUS RECTIFICATION Consequently.⋅ ( ρA – ρB ) ρ 23 = ρ B + --------------------------------- 23°C – 22.63 After rounding.01 kg/m³ ρC = ρ(24%m.⋅ ( 24 – 23 ) = 23 .with ethanol/water mixture . 6.01 ) = 963.1. 23°C) = 961.53 kg/m³ As a result. 11 kg ⁄ m 3 Correspondingly. G.0 V3.10/2009 CE 600 CONTINUOUS RECTIFICATION Re experiment aim 4.6 15:06 82.T. Gerätebau.N. Progression over time of the ethanol concentration in the top product 6 Experiments . 6.U.4 shows the progression over time of the ethanol concentration in the top product: Time Fig. Barsbüttel. To present the change over time in the ethanol concentration in the top product wE in %m All rights reserved.4 Clock Ethanol mass fraction wE in %m 14:41 85.9 14:52 83. Germany 10/2009 Fig.with ethanol/water mixture 83 . 6. at start of experiment mE(End): Ethanol mass.with ethanol/water mixture . At this point the mixture and ethanol masses at the start and end of the experiment are compared: The following examples illustrate the graphical symbols used below: m: Mixture mass.2): 84 6 Experiments .Evap ) (6.): Ethanol mass fraction in top product m(T. Any conflicts arising from the mass balances indicate errors in evaluation or inaccurate measurement data.2) The following table consolidates the values from Tab.pr. ) + m ( B.pr. general wE : Ethanol mass fraction. general m(Start): Mixture mass. 6.. To check the concentrations by means of mass balances It is useful to check the measured values with the aid of mass balances.10.pr. page 81 and adds them together according to the formula (6.1) where · m ( End ) = m ( T . top product Mixtures mass balance: To be checked: m ( Start ) = m ( End ) (6.pr. general m E: Ethanol mass.10/2009 CE 600 CONTINUOUS RECTIFICATION Re experiment aim 5. at end of experiment wE(T.): Mixture mass. ) = m ( T. in g m(Start) m(Start) 9695..N. G.4) and (6. 6.4) The ethanol mass fractionwE is defined as the ratio of the ethanol mass mE to the mixture mass m.0 9611.pr.10.pr.11. net. This enables the individual ethanol masses to be expressed as the product of the mixture mass and the mass fraction.10/2009 CE 600 CONTINUOUS RECTIFICATION Mass. page 85 are evaluated using the equations (6. Gerätebau.g. the resultant ethanol mass balances are: To be checked: m E ( Start ) = m E ( End ) (6.3) where m E ( End ) = m E ( T. page 81 and Tab.pr.pr. (6.Evap) ------ 8219.U.T.5) The following table summarises how the values from Tab.Evap ) (6.with ethanol/water mixture 85 .1) and(6. Barsbüttel. Germany 10/2009 m(End) V3. for: · m E ( T .pr. 6. e. Ethanol mass balance: In line with the mass balances for the mixtures..2). ) (6.1% of the original mixture mass present. ) + m E ( B. 6.0 ------ m(T.0 9695.5 m(B. ) × w E ( T.5 Total Tab.) ------ 1392.pr.pr.5): 6 Experiments . Mixture balancing The comparison of the two values shows that at the end of the experiment there is still 99.11 All rights reserved. Start End m(.5 9611.5 ------ ------ ------ T.3...12 V3.) g %m g g %m g Start 9695.pr.0 ------ 2307.9% of the original ethanol mass present.5 83.6 under item 5..Evap ------ ------ ------ 8219... 6.0 23.) mE(..10/2009 CE 600 CONTINUOUS RECTIFICATION Designation . Ethanol balancing The comparison of the two values shows that at the end of the experiment there is still 104.8 2307.0 15..with ethanol/water mixture .6 1164..pr... 86 6 Experiments ..) mE(.0 B..) wE(.. This surprising result is commented upon in chapter 6.) m(.) wE(.3 1257..5 ------ 2421.5 9695.. ------ ------ ------ 1392.5 Total Tab. 10/2009 CE 600 6. While the equilibriums are being created.1.U.51. Gerätebau. top product and bottom product The initial mixture was separated into the top product.with ethanol/water mixture 87 . page 78 shows the profiles at column start-up. The time between reaching the boiling temperature in the column head and the initial distillate in the phase separation tank (IV) is about 5minutes under the selected conditions. Some of the temperature curves have a kink in them during heat-up. 6 Experiments . Re 2. 6. and the bottom product. Germany 10/2009 Re 1.N. A kink of this kind can be interpreted as forming the equilibrium between vapour and liquid. the equilibriums have formed and the differential pressure in the column increases much less markedly. To determine the ethanol concentration in the initial mixture. The ethanol mass fraction in the top product is greater than in the initial mixture by a factor of 3. Barsbüttel. on occurrence of the first condensate.T. assessment The comments and assessment are based on the pre-defined experiment aims: All rights reserved. When the first distillate occurs. To record the measured value using the data acquisition program (temperature and pressure profiles) Fig. To concentrate the ethanol and Re 3. with increased ethanol content. with reduced ethanol content. the pressure loss in the column increases steadily.3. G. The temperature rise in the individual plates from bottom to top is clearly traceable.6 CONTINUOUS RECTIFICATION Comments. The cause of this is the halving of the much cooler reflux flow into the column head (reflux temperature T13 at 14:30 around 25°C).3. so the column loses condensate. The reaction of the temperatures in the column and column head is rapid. in particular. page 79 shows the differential pressure and temperatures at the start of rectification.10/2009 CE 600 CONTINUOUS RECTIFICATION Fig. heater from 20 to 30%). New equilibriums are formed. Operations are aborted by switching off the heater (0%) at around 15:06 hours. The purpose of this delay 5 minutes after the actual abort is to obtain as much top product as possible under conditions similar to those during operation. the mixture of cooler reflux and newly formed condensate on the plates becomes warmer. page 79 shows the profiles at the end of rectification. The reflux ratio R was changed from 50 to 100% at 15:11 hours. As a reaction to the larger flow of cooler reflux (at 15:11 hours around 27°C) into the column head. The effect of the increase in heating power is felt only slowly. 6. however. 6. 88 6 Experiments .with ethanol/water mixture . an accelerated fall in the temperatures in the upper area of the column is detected. identifiable by the flat rate of rise of the curve for the evaporator temperature T3. The fastest reaction is on the column head and the upper plates. At the same time the steam pressure falls. The temperatures on the upper plates 5 and 7. That is to say.2. Then the last top product sample is taken. Fig. At 14:30 hours the operating conditions are adjusted (reflux ratio R from 100 to 50%. because of the reduced reflux. rise rapidly. An initial rapid drop in temperatures by 4 to 8°C is detected. A rapid reaction does occur. page 83 shows the decrease in the ethanol mass fraction wE in the top product. 6. G. All rights reserved.9 percentage points in the course of the experiment.U.4. To present the change over time in the ethanol concentration in the top product Fig. The decreasing concentration in the evaporator then results in a reduced concentration in the top product. Germany 10/2009 At first glance that appears a substantial decrease. Barsbüttel. Gerätebau.N.T. 6 Experiments . As a result. It is seen that wE decreases by 3. the bottom product in the evaporator loses ethanol in the course of the experiment.with ethanol/water mixture 89 . The reason for this decrease is that there is a greater proportion of ethanol in the newly created top product than in the bottom product in the evaporator.10/2009 CE 600 CONTINUOUS RECTIFICATION Re 4. 10/2009 CE 600 CONTINUOUS RECTIFICATION Re 5. Fig.9% of the original ethanol mass present.1% of the original mixture mass present. A similar loss as in the case of the mixture masses would be expected. The measurement error for this areometer is composed of the actual instrument error 6 Experiments . There cannot be an actual increase in ethanol mass. Of importance to the balancing operation are masses and mass fractions. the areometer shown adjacent was used. an investigation is conducted as to whether a realistic value is produced when measurement inaccuracies are taken into account. Of these two measured values. because both the temperature and the density are incorporated into the calculation of mass fractions. 6. and due to evaporation. To check the concentrations by means of mass balances Evaluation of the experiment shows that at the end of the experiment there is still 99. Taking into account the losses during sampling and transfer.5 90 Areometer used To measure the density. these values are of a realistic magnitude. By contrast. because no chemical conversion takes place in the rectification unit. the density has the greater influence. it is surprising that at the end of the experiment there is still 104. Consequently. The influence of the mass fractions on the balancing result is much more marked.with ethanol/water mixture . The accuracy in determining masses is extremely high. .001kg/L affects the ethanol mass fraction wE (corrected values are shown here in blue). Designation . The measurement error for the areometer used is unfortunately not specified.6 Tab.974 15. The following Tab. 0. Values Corrected values ρ(.pr..T...13 shows how the variation in density by 0.975 14. Gerätebau.pr.10/2009 CE 600 CONTINUOUS RECTIFICATION All rights reserved...) wE(..with ethanol/water mixture 91 .800 to 1. 6.832 83.Evap 0.U.962 23. 6.002kg/L. Germany 10/2009 (Scale does not precisely match the actual penetration depth) and the read error (meniscus formation on the scale.000kg/L. only the effect of the read error is investigated here: The measuring range of the areometer is 0. Consequently.N. Barsbüttel. The difference in density between two graduations on the scale is 0.6 0.K(.13 V3. Influence of density measurement error on ethanol mass fraction 6 Experiments .4 T. G..8 0..3 0.) wE.2 B.) kg/L %m kg/L %m Start 0. Consequently.001kg/L.833 83. the read error is estimated as ± 0. parallax).961 24.) ρK(... Ethanol balancing.4 2366.0 9611..14): Designation .) wE. 6...K(.0 24.5 Total Tab.5 83. Start End m(.) m(.) mE.K(.. with influence of density measurement error The comparison of the two values shows that at the end of the experiment there is now still 99.Evap ------ ------ ------ 8219.5 B.2 1158..pr.0 ------ 2366.14 V3..pr.7% of the original ethanol mass present.K(...with ethanol/water mixture . 92 6 Experiments .10/2009 CE 600 CONTINUOUS RECTIFICATION These corrected values result in the following balance (see Tab.0 14.001kg/L alters the balance by more than 5 percentage points.5 ------ 2358....) wE.) mE..6 1200..) g %m g g %m g Start 9695. 6.K(. ------ ------ ------ 1392.. The apparent contradiction can thus be explained solely by the areometer read error.0 ------ ------ ------ T.0 9695. The influence of the densities here is so great that a change in density of 0.. 10/2009 CE 600 CONTINUOUS RECTIFICATION 6.4 Example of a continuous experiment, V7 6.4.1 Experiment aims Experiment aims are: All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 1. To concentrate the ethanol 2. To record the measured value using the data acquisition program (temperature and pressure profiles) 3. To determine the ethanol concentration in the initial mixture, top product and bottom product 4. To present the change over time in the ethanol concentration in the top and bottom products 5. To check the concentrations by means of mass balances 6.4.2 Experimental setup Connected CE 600 unit, with accessories as set out in chapter 5.2, page 37. 6.4.3 Performing the experiment • Observe the safety instructions (see chapter 3, page 19) • Prepare the unit as set out in chapter 5.5.1, page 44. Open the manual stop valve underneath the pressure gauge. • The requirement is a canister containing more than 19L of initial mixture, ethanol: 25%m, water: 75%m (new addition, e.g. for 20L, with 4808g ethanol and 14425g water). • Mix the initial mixture in the canister. 6 Experiments - with ethanol/water mixture 93 10/2009 CE 600 CONTINUOUS RECTIFICATION • Identify the density and temperature of the initial mixture. Check the concentration. • Transfer the initial mixture from the canister into the two feed tanks (VI). Use measuring cups for this, and weigh the content of each cup (net weight of each). Fill the feed tanks up to their 5litre marks. Also weigh the residue in the measuring cup (after pumping out, pour into feed tank). • Transfer 9 of the 10L of initial mixture from the feed tanks through the column into the evaporator (see chapter 5.6.2, page 47). While transferring, open the stop valve on the column. Switch the pump off when the 9L level is reached according to the markings on the feed tanks. • Transfer additional initial mixture from the canister into the two feed tanks. Use measuring cups for this, and weigh the content of each cup (net weight of each). Fill the feed tanks up to their 5L marks. Also weigh the residue in the measuring cup. • Check whether the heat exchanger (VII) is switched for feed heating. • Press Reset on the differential pressure display (item 23 in Fig. 2.6, page 10 ). • Unit operation by PC. Make the settings for data acquisition, open the measured value file (see chapter 2.4.2, page 13). • Set the reflux ratio to 100% initially • Open the condenser water supply and adjust it to about 300L/h. • Switch on the heater. Initial fixed value 100%. 94 6 Experiments - with ethanol/water mixture 10/2009 CE 600 CONTINUOUS RECTIFICATION • When evaporator temperature T3 = 80°C is reached, reduce the heater to the fixed value 25%. • Wait until distillate appears at the top tube of the phase separation tank (IV) and reflux begins. After waiting 5minutes, change operating conditions: All rights reserved, G.U.N.T. Gerätebau, Barsbüttel, Germany 10/2009 – Start feed in column, pump (X) on at 20% – Reflux ratio from 100 to 25% – Open valve slightly from evaporator to front bottom product tank (see chapter 5.5.1, page 44). – Note down the volume in the evaporator – Keep the level in the evaporator as constant as possible, adjusting the valve setting as necessary. • When the minimum sample volume is reached, withdraw the top product from the top product tank (V). Determine the mass, density and temperature. Keep the sample (for a later mixed sample). Note down the volume in the evaporator. Perform a new measurement as soon as the minimum sample volume has been reached again. • When the minimum sample volume is reached, withdraw the bottom product from the bottom product tank (VIII). Determine the mass, density and temperature. Keep the sample (for a later mixed sample). Note down the volume in the evaporator. Perform a new measurement as soon as the minimum sample volume has been reached again. 6 Experiments - with ethanol/water mixture 95 density and temperature.6.with ethanol/water mixture . Shut off the water supply. • Measure the remaining bottom product (totally drain bottom product tank). • Measure the remaining top product (residue from top product tank together with residue from phase separation tank). weigh it and mix it in the second canister. • Pour together and intermingle the previous bottom product samples and measure the total mass. density and temperature. • Fill canister with unused initial mixture and with top product and the two bottom products. density and temperature. Mix well. page 48). after adding 5L feed: – Pump off – Heater off – Close valve from evaporator to bottom product tank • 5minutes after aborting. • Pout together and intermingle the previous top product samples and measure the total mass. This provides a new initial mixture for the next experiment. Drain off the cooled bottom product. 96 6 Experiments . change reflux ratio to 100%.10/2009 CE 600 CONTINUOUS RECTIFICATION • Abort e. • Cool the bottom product from the evaporator (see chapter 5. determine the mass. Take a sample of the bottom product mixture.g. determine density and temperature.3. density and temperature. determine mass. U.4. 6. with all measured data records. G. The selected time bands are identical to the batch experiment: • Column start-up until production of the first distillate • Start of rectification under operating conditions • End of rectification under operating conditions The measured values for the selected time bands are imported into MS-Excel (see measured value tables Tab.4.T.2.4 Measured values 6. Barsbüttel.4. A tabular representation of the complete measured value file. page 13).17). The MS-Excel Import function is used to import the measured values. 6.4.dat” file format.1 Measurement data from the data acquisition program (experiment aim 2) All rights reserved. this produces more than 5040 measured values (two measured data records per minute.10/2009 CE 600 CONTINUOUS RECTIFICATION 6. 6 Experiments .with ethanol/water mixture 97 . the measured values were saved in “. This measured value file contains a chronological sequence of measured data records.15 to Tab. a selection was made to depict the most informative time bands. would be too extensive to set out at this point. each with 21 measured values).N. Germany 10/2009 Using the data acquisition program. Gerätebau. Consequently. Based on a minimum recording period of 120 minutes. For this experiment an interval of 30 seconds was selected (representing the time between recording of two measured data records). A measured data record is a snapshot of all the measured values at the given point in time (see also chapter 2. 5. pump Y3=20%). these measured value tables also contain the three control variables Y1 to Y3.with ethanol/water mixture . The graphical view is presented in chapter 6.10/2009 CE 600 CONTINUOUS RECTIFICATION Alongside the differential pressure P1 and the temperatures T1 to T16.1. fixed values were programmed on PC rather than using the software controllers. 98 6 Experiments . this enables the start and end of the actual experiment (here 16:35 and 17:44 hours) to be determined from the measured value tables. reflux ratio Y2=25%. page 102. Using the defined operating conditions (heater Y1=25%.4. In the experiment described here. 0 23.9 87.2 24.6 22.3 14.2 24.3 79.1 24.8 16.1 24.8 23.9 22.8 83.2 24.9 23.8 13.1 61.1 80.8 23.8 82.6 79.0 23.0 87.8 22. measured values at column start-up 99 .3 80. Gerätebau.6 80.9 22.6 82.8 55.4 0.0 12.8 85.0 24.7 79.4 87.0 0.6 86. Germany 10/2009 10/2009 CONTINUOUS RECTIFICATION V7.0 24.6 82.2 86.8 24.7 52.8 79. Y3: Controller Outputs for heater.4 81.8 24.1 22.8 82.9 24.1 24.7 25.0 22.3 61.9 81.6 22.5 80.3 24.9 24.5 86.1 13.8 79.1 24.9 22.6 86.3 80.4 80.6 79.7 23.6 22.0 24.2 79.1 24.8 79.0 24.1 15.6 23.2 85.6 22.0 81.8 13.3 14.1 80.7 15.7 23.0 22.9 88.1 85.9 22.9 24.2 87.0 4.1 8.0 79.3 28.3 24.4 79.0 23.9 24. 6.0 23.0 24.0 73.3 15.1 24.1 23.0 24.0 70.1 22.15 6 Experiments .0 24.9 23.1 23.9 23.6 22.2 14.7 22.1 24.1 23.5 79.4 11.2 79.9 84.8 80.1 24.1 79.8 13.3 79.9 4.7 23.1 80.1 23.2 24.7 80.8 23.0 22.7 80.0 79.0 24.9 22.4 88.3 49.5 79.0 0.5 68.0 24.0 6.2 80.4 79.2 85.9 23.5 82.7 23.0 86.0 24.2 79.5 24.1 87.3 88.1 14.7 79.0 23.T1 °C T2 °C T3 °C T4 °C T5 °C T6 °C T7 °C T8 °C T9 °C T10 °C T11 °C T12 °C T13 °C T14 °C T15 °C T16 °C Tab.8 23.0 22.7 79.2 88.2 12.4 87.3 80.8 13.0 23.5 27.4 9.4 1.8 13.0 24. Barsbüttel.4 12.2 24.2 24.0 25.1 24.0 85.2 23.0 30.3 24.0 23.4 71.9 24.9 23.0 24.5 80.2 24.1 24.6 22.1 24.2 14.2 83.4 86.3 81.0 24.0 78.with ethanol/water mixture 24.7 38.7 23.0 24.3 80.2 78.0 24.7 13.5 87.8 72.8 12.0 24.1 24.4 22.6 22.2 81. 22.0 23.5 22.0 24.1 14.3 85.1 55.4 11.1 14.1 88.3 23.9 23.1 23.7 23. R Y3.4 73.8 13.7 23.8 13.5 52.8 13.7 23.8 79.8 13.0 24.1 28.5 22.9 23.3 88.9 80.9 23.0 24.7 23.8 22.3 14.8 13.3 36.1 24.9 14.6 11.0 24.7 23.1 80.1 24.1 83.2 79.0 63.1 23.6 67.6 24.9 23.8 68.8 13. Reflux ratio.6 80.1 24.7 24.4 83.0 11.8 24.2 35.6 87.0 0.0 24.8 22.2 63.6 85.2 24.5 79.9 23.5 22.0 87.0 23.0 24.1 24.1 14.1 14.5 79.1 65.6 80.5 79.6 22.5 14.8 28.7 23.0 24.5 83.0 0.0 24.9 22.6 22.6 22.8 27.0 22.7 87.8 13. G.8 88.0 23.1 80.8 13.8 13.8 23.1 14.7 69.9 81.3 85.8 23.8 13.1 78.5 27.0 79.7 78.0 24.9 23.8 14.3 81.9 79.7 78.6 22.5 1.2 80.0 24.0 24.8 23.1 14.6 86.9 53.9 22.2 14.1 14.2 14.8 23.2 23.0 81.1 14.0 24.0 24.4 86.3 81.0 24.8 23.4 86.2 15.9 23.1 0.7 23.4 80.5 81.1 22. Y2.0 84.0 79.0 85.6 23.9 24.0 24.0 23.1 24.0 11.2 80.0 24.5 14.1 24.2 82.1 23.9 23.0 24.1 80.3 33.6 22.0 24.7 54.8 84.0 16.6 24.8 83.0 24.8 13.7 23.6 83.2 24.7 23.0 24.6 80.9 80.6 86.0 24.1 14.6 79.8 13.1 24.2 23.3 82.0 24.0 16.0 72.0 24.8 23.4 74.6 22.6 22.9 86.0 23.4 0.8 23.6 22.7 23.8 2.7 13.3 79.9 13.8 23.9 22.8 13.0 23.3 80.8 13.1 24.8 24.0 24.1 80.8 23.0 88.6 24.0 24.8 13.2 85.7 23.2 78.0 0.3 88.0 23.4 80.2 87.8 79.1 81.3 88.0 24.2 79.9 24.0 23.9 22.7 79.3 87.1 12.9 24.0 85.9 24.0 24.9 22.6 87.5 22.1 24.9 23.6 22.0 82.9 23.9 23.0 80.4 79.1 24.8 13.0 24.8 82.5 24.1 24.6 14.7 23.9 22.7 23.0 82.8 82.5 79.1 14.6 80.5 86.0 86.0 24.8 23.0 79.8 13. Y1.7 87.1 80.1 14.2 82.4 14.7 79.8 80.1 24.7 22.2 79.9 24.6 7.7 15.6 22.1 0.8 79.2 78.1 16.9 23.0 23.9 80.1 0.0 24.U.2 81.6 22.0 0.9 30.7 23.9 23.9 53.0 24.4 84.7 23.9 Temperatures and differential pressure according to flow diagramm / system diagram.9 23.8 23.9 22.1 23.3 79.1 79.7 79.2 24.0 24.0 24.5 22.5 88.5 15.7 83.7 23.8 77.1 14.7 23.0 24.4 81.7 23.1 78.0 24.0 24.0 23.7 23.1 0.4 88.3 33.1 24.7 22.9 24.1 84.8 84.6 80.5 88.6 13.7 23.N.8 80.0 23.1 23.8 83.1 25.7 23.9 23.7 13.7 23.3 85.0 24.9 22.7 23.5 79.0 80.7 84.0 24.7 23.0 23.0 80.0 28.T.6 22.1 83.9 23.0 24.8 85.0 24.1 23. frequency of pump drive.2 23.8 31.6 83.5 79.1 0.4 79.8 23.9 23.3 82.9 80. Pel Y2.8 83.4 71. f mbar % % % CE 600 16:10:36 16:11:06 16:11:36 16:12:06 16:12:36 16:13:06 16:13:36 16:14:06 16:14:36 16:15:06 16:15:36 16:16:06 16:16:36 16:17:06 16:17:36 16:18:06 16:18:36 16:19:06 16:19:36 16:20:06 16:20:36 16:21:06 16:21:36 16:22:06 16:22:36 16:23:06 16:23:36 16:24:06 16:24:36 16:25:06 16:25:36 16:26:06 16:26:36 16:27:06 16:27:36 16:28:06 16:28:36 16:29:06 16:29:36 15:59:36 24.9 23.9 81.6 22.7 64.6 22.7 23.8 28.1 14.1 60.0 -0.0 0.9 23.3 12.3 80.2 88.7 24.4 80.6 26.0 24.7 15.8 13.8 81.6 58.5 79.2 14.4 79.8 13.3 56.1 79.4 79.7 24.7 80.0 24.0 11.1 22.1 14.9 23.6 11.6 22.8 13.8 80.0 24.9 24.8 16.1 0.3 30.7 23.8 51.7 82.7 23.9 24.0 24.7 22.8 t hh:mm:ss All rights reserved.0 87.0 23.8 13.2 24.5 87.7 23.8 24.6 32.9 23.9 10.4 81.0 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 0 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P1 Y1.7 23.8 13.7 23.5 86.9 23.0 23.2 88.2 81.2 79.5 84.8 23.0 22.9 6. 4 15.2 80.7 80.0 85.7 23.9 80.4 T16 °C 14.1 89.3 83.3 89.2 80.2 24.1 85.1 80.4 80.4 86.7 80.3 80.5 89.3 85. frequency of pump drive.0 T9 °C 80. 6.7 81.5 15.4 25.4 86.3 24.5 80.5 89.6 86.2 T5 °C 85.7 25.9 80.9 81.1 82.3 16.9 29.0 24.5 80.3 80.2 24.8 81.16 Temperatures and differential pressure according to flow diagramm / system diagram.0 14.2 25.8 85. f mbar % % % CE 600 Tab.9 80.7 23.4 80.5 15.4 86.4 13.4 47.4 15.9 81.5 87.4 80.1 25.9 82.2 25.8 24.9 82.7 15.6 80.5 83.3 25.6 80.5 80.4 80.2 24.3 80.5 89.1 48.6 17.3 86.9 86.5 27.7 89.4 15.2 89.5 15.6 82.0 24.6 86.3 24.6 27.5 87.1 26.9 14.1 80.5 85.6 23.5 85.3 81.1 86.7 81.0 25.0 25.3 15.5 80.5 85.4 24.7 85.4 80.8 85.0 13.2 24.4 24.7 86.6 80.0 13.7 89.2 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 100 100 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 0 0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 P1 Y1.6 80.6 26.3 25.8 T15 °C 16.6 25.5 15.1 86.7 13.5 15.4 27.5 24.0 80.5 15.3 13.0 81.0 14.7 13.5 80.2 24.0 24.1 80.9 14.5 24.7 15.6 18.3 18.2 80.1 80.9 81.4 80.3 80.3 80.0 81.1 80.5 80.5 80.9 81.8 13.3 24.7 80.9 23.6 89.0 16.4 14.7 80.1 80.0 80.6 87.6 17.3 24.3 86.5 24.8 89.5 80.5 15.7 83.8 80.5 80.2 80.2 87. R Y3.6 24.5 25.8 80.4 86.6 80.1 86.4 87.8 81.5 80.6 80.6 80.6 15.1 25.0 14.0 26.5 80.6 89.8 80.5 86.1 14.6 80.6 86.8 80.3 24.9 80.3 25.0 80.1 81.4 87.6 80.7 40.1 25.9 80.2 80.7 80.8 83.3 25.6 83.3 15.2 80.0 85.1 13.0 25.3 80.0 32.5 24.7 15.3 80.7 80.9 27.0 26.7 80.9 86.0 14.5 15.5 15.0 80.3 15. T1 °C t hh:mm:ss 10/2009 CONTINUOUS RECTIFICATION V7.4 24.9 80.1 81.9 80.0 27.3 80.9 25.6 85.6 80.6 80.7 25.1 14.8 25.4 25.3 25.8 80.2 25.4 89.5 89.5 80.4 24.0 81.0 25.8 80.2 T14 °C 14.5 86.2 80.6 86.0 85.4 80. Reflux ratio.2 24.9 34.5 15.9 81.8 24.6 13.8 13.0 49.4 80.9 13.5 15.8 13.6 80.2 87.6 80.8 T2 °C 89.2 86.3 80.2 24.9 14.6 80.9 23.7 85.8 86.9 81.4 25.8 80.4 24.5 24.9 24.4 80.8 13.7 79.5 25.4 89.7 80.7 25.1 86.2 81.4 89.0 83.1 80.7 81. Pel Y2.5 T7 °C 81.9 14.6 80.7 15.7 81.4 24.7 80.8 81.4 15.6 80.9 79.9 26.6 80.3 80.0 85.0 13.5 80.9 87.6 80.5 23.4 80.7 80.9 79.6 86.9 80.9 13.3 82.4 24.1 15.5 39.0 13.4 25.8 80.2 13.3 80.3 24.9 T4 °C 87.5 80.7 89.3 15.6 80.3 80.8 79.0 14.8 14.2 81.8 T3 °C 87. measured values at start of rectification 6 Experiments .3 80.2 80.3 80.8 89.3 24.5 83.1 85.8 13.4 38.4 81.6 80.5 80.9 89.8 13.4 15.5 15.7 23.3 25.1 28.8 25.4 24.1 89.5 24.9 43.3 80.1 80.5 24.1 80.0 14.6 81.1 80.0 80.4 89.3 80.3 82.5 80.5 37.1 25.8 85.0 86.4 24.7 86.8 85.9 80.3 28.0 81.2 22.8 14.6 80.7 80.3 T12 °C 25.6 17.6 80.7 81.4 31.9 80.with ethanol/water mixture .0 82. Y3: Controller Outputs for heater.6 85.9 80.8 80.0 80.8 79.3 25.6 80.6 81.5 89.1 25.3 24.9 15.1 16.0 14.9 13.4 81.5 15.7 81.6 80.6 85.6 80.4 24.1 80.3 89.6 15.0 25.3 12.7 80.5 15.4 80. Y2.8 80.0 25.5 15.1 23.6 15.7 45.8 82.6 36.3 25.7 18.0 14.4 89.3 80.1 16.5 15.5 81.0 80.8 85.4 86.5 14.3 T8 °C 80.1 80.3 25.9 46.2 24.8 84.0 25.6 80.8 13.3 80.7 86.1 89.5 80.1 17.5 89.0 86.9 80.7 80.5 15.3 25.3 80.4 24.9 26.3 25.8 86.1 81.1 80.4 89.5 80.6 80.3 80.7 86.7 89.4 89.4 16:34:36 16:35:06 16:35:36 16:36:06 16:36:36 16:37:06 16:37:36 16:38:06 16:38:36 16:39:06 16:39:36 16:40:06 16:40:36 16:41:06 16:41:36 16:42:06 16:42:36 16:43:06 16:43:36 16:44:06 16:44:36 16:45:06 16:45:36 16:46:06 16:46:36 16:47:06 16:47:36 16:48:06 16:48:36 16:49:06 16:49:36 16:50:06 16:50:36 16:51:06 16:51:36 16:52:06 16:52:36 16:53:06 16:53:36 100 23.6 80.6 22.7 80.0 15.3 80.4 24.0 85.9 14.3 80.4 89.3 80.0 25.9 81.9 23.8 80.2 25.6 81.0 80.7 81.9 86.3 80.5 89.6 25.7 86.6 80.6 80.3 25.7 81.2 25.8 80.5 82.3 80.3 80.9 80.0 14.7 87.5 41.1 80.1 86.6 26.2 81.2 81.3 80.5 80.9 13.3 80.5 80.4 86.3 80.8 79.0 88.6 80.1 81.1 80.1 24.8 T13 °C 23.7 80.6 86.2 25.6 89.4 80.3 80.22.6 14.0 85.4 16.5 25.6 80.5 15.6 80.6 30.9 81.5 80.9 83.8 23.1 25.5 42.7 80.1 82.6 80.2 80.8 23.7 80.5 80.2 87.1 25.8 81.2 50.1 80.1 80.2 86.0 22.6 80.5 28.0 85.3 15.6 83.4 86.0 14.1 86.7 16.0 13.8 80.5 15.4 89.9 25.8 79.2 14.8 25.8 14.3 80.4 80.1 87.5 80.3 85.0 13.1 15.1 45.7 81.6 89.0 13.3 83.3 80.2 89.8 13.8 79.3 25.4 80.1 14. Y1.5 24.4 15.1 13.4 80.3 80.1 23.7 79.4 80.5 T11 °C 79.9 80.7 86.2 42.7 T10 °C 80.8 13.5 15.5 24.2 82.4 81.8 85.7 44.0 25.4 80.5 89.0 85.1 85.5 24.8 14.6 86.6 80.6 25.3 89.7 89.5 15.6 80.8 T6 °C 83.1 79.2 80.4 15.9 13.3 80.9 25.3 80.8 86.0 14. 2 73.1 92.4 14.2 85.1 66.9 81.8 91.1 65.1 15.2 92.1 38.4 78.3 20.3 82.6 21.7 57.6 78.9 78.8 63.5 82.9 16.6 0.1 61.6 0.2 29.4 27.6 15.4 92.6 91.9 85.7 37.9 27.0 80.5 27.7 80.5 82. measured values at end of rectification 101 .2 75.7 14.3 82.0 85.7 26.2 17.2 63.5 61.9 T13 °C 32.7 69.0 39.2 24.7 78.4 16.5 45.1 65.8 82.7 40.7 75.1 92.1 14.8 T1 °C t hh:mm:ss All rights reserved.6 82.5 83.1 82.1 82.0 29.0 66.8 18.4 0.3 80.1 74.6 83.0 84.5 76.7 39.3 70.7 55.2 24.9 80.2 77.1 79.5 14.4 14.3 82.4 31.9 63.3 82.6 26.6 86.6 68.7 71.2 67.6 14.0 61. 88.4 92.4 32.5 69.6 74.2 0.2 86.6 76. Reflux ratio.2 24.4 69.8 82.1 76.0 80.2 79.9 69.1 78.5 14.3 22.3 73.7 75.6 72.4 92.2 52.4 60.6 T4 °C 18:33:36 25.1 92.7 10.4 79.8 14.2 15.7 40.6 68.3 76. Barsbüttel.0 22.6 10.2 0.0 31.2 66.4 33.3 24.7 25.9 66.9 15.4 24.9 15.9 27.2 80.3 70.1 14.2 32.0 27.6 62.2 80.8 26.1 38.4 10.4 14.6 82. Pel Y2. Y3: Controller Outputs for heater.2 49.8 77.2 76.0 72.1 85.3 24.3 24.4 71.9 68.5 15.2 27.6 63.7 68.5 76.3 84.2 24.4 0.9 T10 °C 82.4 3.2 63.2 88.8 78.0 81.17 6 Experiments .4 24.7 72.2 0.1 28.3 85.7 10.4 T12 °C 27.0 73.1 81.6 10.0 81.9 79.8 22.6 82.8 91.4 63.7 65.3 26.U. Y1.6 T6 °C 85.4 0.6 T5 °C 0.8 82.4 64.1 85.6 65.4 63.9 71.5 15.6 82.3 39.1 92.8 65.1 62.2 84.9 72.7 73.7 27.3 92.5 15.7 4.5 2.9 69.7 66.1 62.2 82.2 86.1 70.6 63.1 16.9 16.4 80.5 71.3 68.4 63.8 15.8 28.3 66. 6.2 24.5 66.7 57.1 85.2 16.5 80.8 13.6 86.1 29.9 26.0 21.2 88.2 24.with ethanol/water mixture 0 25 25 25 25 25 25 25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 100 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 0 20 20 20 20 20 20 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P1 Y1.6 68.0 82.6 91.1 54.2 68.6 76.7 14.8 68.0 76.8 68.0 73.5 82.3 23.4 15.9 13.4 63.2 78.4 92.1 78.9 79.9 13.3 92.8 79.0 67.2 0.8 14.1 24.9 65.5 77.5 72.9 38.3 60.9 57.6 17:40:36 17:41:06 17:41:36 17:42:06 17:42:36 17:43:06 17:43:36 17:44:06 17:44:36 17:45:06 17:45:36 17:46:06 17:46:36 17:47:06 17:47:36 17:48:06 17:48:36 17:49:06 17:49:36 17:50:06 17:50:36 17:51:06 17:51:36 17:52:06 17:52:36 17:53:06 17:53:36 17:54:06 17:54:36 17:55:06 17:55:36 17:56:06 17:56:36 17:57:06 17:57:36 17:58:06 17:58:36 17:59:06 17:59:36 T2 °C 16.6 82.3 63.4 22.5 92.1 62.4 27.9 77.6 86.3 84.9 79.4 92.4 92.6 75.1 77.1 27.3 0.9 79.2 24.6 71.2 77.2 0.0 27.6 64.1 71.1 62. Germany 10/2009 10/2009 CONTINUOUS RECTIFICATION V7.7 63.8 76.3 15.2 27.T.9 71.3 T3 °C 10.3 82.9 13. G.6 70.6 29.9 14.6 67.8 80.5 81.4 74.3 82.0 79.7 86.3 85.7 75.3 51.8 13.2 88.4 24.5 20.6 71.1 47.4 92.3 70.4 24.0 78.9 91.9 13.1 14.3 81.3 81.1 13.4 92.3 32.9 62.2 24.2 0.0 13.4 92.3 53.1 73.3 72.2 73.0 13.1 70.1 63.4 6.8 86.9 16.8 69.4 77.0 0.4 62.4 78.9 22.3 15.6 74.9 74.3 26. R Y3.7 74.8 91.4 82.1 71.7 71.9 14.0 70.9 21.8 64.2 84.2 24.0 14.2 0.8 77.3 38.4 24.9 74.7 86.2 26.8 77.0 76.7 50.9 67.1 86.5 75.6 T7 °C 85.6 0.2 84.3 T15 °C T16 °C Tab.7 63.6 16.9 14.5 24.0 66.2 15.2 86.6 20.2 0.2 34.6 84.1 23.2 26.0 91.6 69.0 85.2 88.3 24.3 82.8 91.3 82.2 26.4 92.3 92.8 78.3 79.0 85.9 14.4 0.4 26.8 14.6 14.3 35.1 82.1 24.1 16.5 27.2 24.5 14.3 24.0 65.7 29.5 24.2 67.0 32.3 66.0 16.6 72.6 67.0 74.9 68.2 81.7 64. frequency of pump drive.2 88.5 T8 °C 84.5 82.9 23.6 82.6 15.9 16.1 78.2 77.4 25.2 32.4 14.1 24.1 30.1 79.3 84.6 75.0 30.9 76.3 72.8 91.1 24.2 27.4 59.1 63.9 62.0 15.7 49.9 69.4 36.9 13.9 16.0 16.86.5 71.8 76.9 72.3 82.4 76.4 92.7 65.5 14.4 92.8 72.7 74.2 85.3 50.5 0.5 0.0 61.5 0.5 0.3 30.4 66.2 83.6 76.6 69.9 28. Y2.7 81.7 27.7 23.9 68.0 26.8 53.3 82.5 79.7 16.2 0.8 78.6 65.8 67.0 26.2 24.2 82.2 56.0 13.1 27.3 81.3 22.1 76.5 78.3 80.8 69.4 82.4 55.8 86.3 84.3 64.1 81.1 81.1 67.3 64.1 63.8 91.6 26.8 T9 °C 82.5 72.2 69.7 65.5 25.0 15.N.9 26.5 0.7 82.6 64.2 0.8 22.4 92.5 62.7 81.0 85.7 72.3 62.4 63.2 92.2 69.7 0.5 61.7 82.4 14.0 13.9 71.3 64.8 73.2 84.7 81.6 14.3 71.8 28.0 15.2 86.9 72.9 26.6 10.6 30.9 65.2 68.8 74.3 22.3 75.5 0.1 32.9 13.0 64.5 20.7 29.8 91.0 75.5 46.8 77.7 67.2 T14 °C 14.5 63.9 60.9 65.7 27.3 16.4 92.0 61.1 84.4 82. f mbar % % % CE 600 Temperatures and differential pressure according to flow diagramm / system diagram.4 24.0 27. Gerätebau.0 16.2 16.4 82.5 14.5 77.3 82.2 32.6 43.2 80.0 91.0 25.4 79.5 68.0 15.6 14.6 79.8 67.1 82.4 60.3 73.0 70.7 20.2 62.3 88.2 27.8 82.7 64.6 86.7 78.8 70.0 87.5 0.4 14.2 72.9 76.6 26.6 41.9 80.0 T11 °C 82.5 62.7 73.8 64.0 63.0 27.9 75.8 65.3 29.9 92.9 66.9 51.5 16.5 63.4 0.2 24.1 68.1 86.6 58.2 24.7 26.4 74.3 16.3 80.3 14.2 68.4 29.4 69.8 91.5 82.9 28.0 67.9 64.0 92. Temperature and pressure profile at column start-up 6 Experiments .4.4. in chapter 6.2 CONTINUOUS RECTIFICATION Self-recorded measured values (without PC assistance) The self-recorded measured values are primarily the masses. Column pressure loss Fig.15. Please note that the diagrams have differing temperature and pressure ranges. Evaporator temperature T6. densities and temperatures of the various mixtures/products. Plate 7 temperature P1. In the course of the experiment they were entered by hand on the “Continuous worksheet” (see Tab.5.4. 6.2. 6. page 118). 6. Time T3.with ethanol/water mixture . These measured values are presented. page 105.10/2009 CE 600 6.18. Plate 5 temperature T12. 6.17 . Plate 3 temperature T10. page 99 to Tab.5 Evaluation 6. Tab. 7. together with the evaluation. Plate 1 temperature T8.6 102 T4.1 Presentation of automatically recorded measurement data (experiment aim 2) 90 15 80 13 70 11 60 9 50 7 40 5 30 3 20 1 10 16:10 16:12 16:14 16:16 16:18 16:20 16:22 16:24 16:26 16:28 -1 16:30 Differential pressure in mbar Temperature in °C The bases of the following diagrams are the measured value tables Tab.2. 6. Top temperature V7.5.4.4. 8 T4. Top temperature V7.U. Plate 3 temperature T10. Temperature and pressure profile at end of rectification 6 Experiments . 6. Temperature and pressure profile at start of rectification 100 14 12 90 10 8 80 6 4 70 2 0 60 17:40 17:42 17:44 17:46 17:48 17:50 17:52 17:54 17:56 17:58 -2 18:00 Differential pressure in mbar Temperature in °C CONTINUOUS RECTIFICATION 78 16:34 Temperature in °C All rights reserved. Plate 3 temperature T10. Plate 7 temperature P1.7 Differential pressure in mbar 92 T4. Plate 5 temperature T12.N. G. Gerätebau. Barsbüttel. Evaporator temperature T6.with ethanol/water mixture 103 . Plate 1 temperature T8.10/2009 26 90 24 88 22 86 20 84 18 82 16 80 14 16:36 16:38 16:40 16:42 16:44 16:46 16:48 16:50 16:52 12 16:54 Time T3. Plate 5 temperature T12. Top temperature V7. 6.T. Evaporator temperature T6. Germany 10/2009 CE 600 Time T3. Plate 7 temperature P1. Column pressure loss Fig. Column pressure loss Fig. Plate 1 temperature T8. 10/2009 CE 600 6.5. The individual mixture masses at the start and end of the experiment have been added together (details follow in this chapter under item 5. 6. together with the total masses and concentrations calculated from them.2.4.18.2 CONTINUOUS RECTIFICATION Evaluation of self-recorded measured values The following Tab. page 80).1. densities and temperatures. 6. The material values originate from Tab. page 56. page 55 and Tab. the ethanol mass fraction E wE was determined from the density and temperature by means of linear interpolation (for description of procedure see chapter 6.To determine the ethanol concentrations: For all the samples.2.).5. page 105 presents the measured masses.3.with ethanol/water mixture . 104 6 Experiments . Re experiment aim 3 . 6. 5 1939. Self-recorded measured values.pr.5 0.0 0.5 1925..970 9.1 Measurement Start. 3. B.1 17:19 B.0 0.3 16:52 B. when 10L reached) 1268. mixture 3204.977 ----- 8580.0 Key: T.2 0.pr.18 V7.2 ----- 17. mixture 1620.pr. 10/2009 Clock Evaluation CE 600 6 Experiments .4 17:29 B.7 0.5 24.with ethanol/water mixture Measurement .5 Start.. mixture.3 0.5 23. 402.2 Total drainage ----- 13.1 ----- 17.9 0. 6.. 477.pr. B. G.. from Evap.0 1944.pr. 1.pr..835 ----- Total drainage ----- 82. T..6 0.975 9.1 ----- End.: Top product.970 9. (+7.pr.) 923.N. Fill feed tank.6 17:16 T. Gerätebau..pr. 2. 3.pr.5 23.1 ----- 86.0 13.0 23.830 9.7 17:10 B.5 (-24. 636.T. 455.All rights reserved.970 9. when 10L reached) 979. with evaluation 1945.1 17:02 B.2 ----- 13.7 17:44 B. B. Individual masses in g 1941.pr.5 CONTINUOUS RECTIFICATION Density net Temperature Product/measurement no. -7g residue 2. Barsbüttel.pr.9635 9.975 9. 1.825 9.3 0.1 ----- 84.1 ----- 17..5 1855.0 8744.: Bottom product.972 ----- ----- 16.5 0.0 1937. 430. 475.5g see above.1 ----- 18.5 26.833 ----- ----- 83.0 24.5 23.5 1935.5 23.0 16:58 T. wE g °C kg/L L g %m Start.. 448.pr.5 22. 424.pr.4 17:44 T.0 1660.1 0.0 1866.2 ----- End. 4.U..0 0.8 0.0 1929.5 25. B..5 23.2 ----- Mass Level Comments ----- End.5 (24.970 9.0 25...pr. Evap ----- 24. Evap: Evaporator 105 Tab.0 End. Individual masses in g 1939. Individual masses in g 1930. 2. 5.pr. from Evap ----- 21. 6. Fill feed tank.5g residue 1. Germany 10/2009 Mass Mass fraction in Evap net Ethanol. 4 17:29 ----- 13.9 106 Ethanol mass fraction Top product Bottom product wE in %m wE in %m 16:52 ----- 18.10/2009 CE 600 CONTINUOUS RECTIFICATION Re experiment aim 4.7 17:44 82.7 17:10 ----- 17.1 ----- 17:19 ----- 17.4 V7.with ethanol/water mixture .0 16.0 16:50 17:00 17:10 17:20 17:30 17:40 Time Clock Fig.1 ----- 17:02 ----- 17.0 10.0 Bottom product wE in %m 18.0 12.6 17:16 84. Progression over time on the ethanol concentration in the top and bottom products 6 Experiments .0 16:58 86. To present the change over time in the ethanol concentration in the top and bottom product Fig.0 14. 6.9 shows the progression over time of the ethanol concentration: wE in %m Top product Time 20.2 13. 6. pr. Barsbüttel.with ethanol/water mixture (6.6) where m ( Start ) = m ( Start.): Mixture mass. at end of experiment m(Evap): Mixture mass in evaporator mE(Feed): Ethanol mass in feed tanks wE(T. To check the concentrations by means of mass balances It is useful to check the measured values with the aid of mass balances. general m(Start): Mixture mass.N.pr.): Ethanol mass fraction in top product m(B. Germany 10/2009 At this point the mixture and ethanol masses at the start and end of the experiment are compared: The following examples illustrate the graphical symbols used below: m: Mixture mass. All rights reserved. G.U. general wE : Ethanol mass fraction. general m E: Ethanol mass.T. Feed ) 6 Experiments . at start of experiment mE(End): Ethanol mass.pr.Evap ) + m ( End. Evap ) + m ( Start.pr. ) + m ( B . Gerätebau.10/2009 CE 600 CONTINUOUS RECTIFICATION Re experiment aim 5. ) + m ( B .. Feed ) and · · · m ( End ) = m ( T .7) (6. bottom product Mixtures mass balance: To be checked: m ( Start ) = m ( End ) (6.8) 107 . Any conflicts arising from the mass balances indicate errors in evaluation or inaccurate measurement data.pr. 0L of the 10.Evap) are produced by adding together the individual mixture masses from Tab.0 5. After pumping the 9. 6. Measuring 1929.5 1937.pr.Evap) 1.. Measuring 1945. Addition of mixture masses The “residue 1”. The other 5..5 3. Measuring 1939.5 24.0 1930.0L is reached before the measuring cup is completely empty. the total volume of 10. 6.0L into the evaporator.5 ------ Residue 2 ------ -7.5 1855. 24.Feed) m(Start.0 ------ 9664. Consequently: m(End. net.Evap) and m(B.5 8744.0 1660.0 Total Tab.0 1866.5 1268.5 8580. 5. The residue is thus the mass of the mixture remaining in the measuring cup.0L remain in the second feed tank.Feed) / 2 = 9664.3 g 108 6 Experiments .0 4. In the course of the experiment. m(Start.0L feed is pumped into the column.Feed) = m(Start.5 Residue 1 -24.with ethanol/water mixture .5g.pr.0 1944.10/2009 CE 600 CONTINUOUS RECTIFICATION The following table illustrates how the values for m(Start.19 V7.0 2. in g m(Start.5 1941.5 979. This “residue 1” results from the fact that when transferring from the last measuring cup into the feed tank (VI).5 / 2 = 4832.5 1925. Measuring 1935.18. page 105: Mass. is included.Feed). Measuring 1939. this “residue 1” is transferred into the feed tanks.Evap) m(B. 7) and (6. Germany 10/2009 m(Start) m(End) m(Start. ) + m E ( B.6) to(6.5 18409.10) (6. Ethanol mass balance: In line with the mass balances for the mixtures.8).Feed) 9664.T..U.0 m(End. the resultant ethanol mass balances are: To be checked: m E ( Start ) = m E ( End ) (6.0 Total Tab.Feed) ------ 4832.pr.5 ------ m(Start.with ethanol/water mixture (6.pr. 6.) ------ 1620. Barsbüttel.10/2009 CE 600 CONTINUOUS RECTIFICATION The following table consolidates the mixture masses calculated above and adds them together according to the formulae (6. G.9) where m E ( Start ) = m E ( Start.0 18237.N.Evap) 8744. ) + m E ( B.pr.11) 109 . (6. Feed ) and · m E ( End ) = m E ( T ..pr. Feed ) 6 Experiments .5 m(B. net.Evap ) + m E ( End. Mixture balancing The comparison of the two values shows that at the end of the experiment there is still 99. Evap ) + m E ( Start.1% of the original mixture masses present.8): Mass.20 V7.Evap) ------ 8580.pr.) ------ 3204.5 ------ m(T.0 m(B. in g All rights reserved. Gerätebau.pr. e.Evap 8744.10/2009 CE 600 CONTINUOUS RECTIFICATION The ethanol mass fraction wE is defined as the ratio of the ethanol mass mE to the mixture mass m.Feed ------ ------ ------ 4832..1% of the original ethanol mass present.with ethanol/water mixture .12) The following table summarises how the values from Tab.. page 105 and Tab.3 2155. Ethanol balancing The comparison of the two values shows that at the end of the experiment there is still 99.1 1124.pr..5 22.0 B..5 16. ) × w E ( T.) wE(. page 109 are evaluated using the equations (6.pr. 110 6 Experiments . ------ ------ ------ 3204.5 Total Tab.5 18409..12): Designation … ..pr..0 ------ 4105..) m(.1 1346. ) = m ( T.0 ------ ------ ------ T.pr.0 18237.) g %m g g %m g Start...2 519. ------ ------ ------ 1620.0 83..3 1077.5 22.) mE(. Start End m(.pr.0 ------ ------ ------ Start..0 13. This enables the individual ethanol masses to be expressed as the product of the mixture mass and the mass fraction.3 1950. 6.21 V7.pr. 6.Evap ------ ------ ------ 8580. ) (6.) mE(.10) to (6.0 ------ 4066.0 B.5 22. for: m E ( T...) wE(.0 End. 6.18.Feed 9664.20.g. on occurrence of the first condensate.N. A kink of this kind can be interpreted as forming the equilibrium between vapour and liquid. Comparison with the factor 3.73. While the equilibriums are being created.6 CONTINUOUS RECTIFICATION Comments. The ethanol mass fraction in the top product is greater than in the initial mixture by a factor of 3.6. Gerätebau. page 102 shows the profiles at column start-up. To determine the ethanol concentration in the initial mixture. top product and bottom products The initial mixture was separated into the top product. The temperature rise in the individual plates from bottom to top is clearly traceable.with ethanol/water mixture 111 . The curves run similarly to those in batch experiment V3. Barsbüttel. the pressure loss in the column increases steadily. assessment The comments and assessment are based on the pre-defined experiment aims: All rights reserved.U. and the two bottom products. page 87) shows that in experiment V7 in continuous mode a better concentration was achieved. 6 Experiments .6.10/2009 CE 600 6.51 from the batch experiment V3 (see also chapter 6. To record the measured value using the data acquisition program (temperature and pressure profiles) Fig. with increased ethanol content. G. with reduced ethanol content.T. 6. Germany 10/2009 Re 1.4.3. Re 2. To concentrate the ethanol and Re 3. Some of the temperature curves have a kink in them during heat-up. with ethanol/water mixture . stop bottom product from evaporator to bottom product tank. Around 16:35 hours the operating conditions are adjusted (start pump at 20%. When the first distillate occurs.8.10/2009 CE 600 CONTINUOUS RECTIFICATION The time between reaching the boiling temperature in the column head and the initial distillate in the phase separation tank (IV) is about 5 minutes under the selected conditions. bottom feed. page 103 shows the profiles at the end of rectification. reflux ratio R from 100 to 25%). The many simultaneous changes take effect at different rates. page 103 shows the differential pressure and temperatures at the start of rectification. and influence each other. As a reaction.7.most rapidly in the upper section. feed heating. Fig. After about 10 minutes the complete system has adjusted to the new equilibriums. The rise is in line with the rising boiling point at reduced ethanol concentrations. switch off heater. Around 17:44 hours operations are aborted by: Stop pump. the equilibriums have formed and the differential pressure in the column now changes only to a minor extent. Fig. and the temperatures slowly rise. 6. start bottom product from evaporator to bottom product tank. 6. 112 6 Experiments . it is seen that the temperatures in the column initially fall . At the same time the differential pressure rises. At first glance that appears a substantial decrease.T. 6. The reason for this decrease is that there is a greater proportion of ethanol in the newly created top product than in the bottom product of the evaporator.9.9 percentage points in the course of the experiment. 6.6. However. The decreasing concentration in the evaporator then results in a reduced concentration in the top product. the bottom product in the evaporator loses ethanol in the course of the experiment. page 79). G. It is seen that wE decreases by 3. Gerätebau. At the same time the differential pressure falls.U. Re 4. An initial rapid drop in temperatures by 2 to 5°C is detected. All rights reserved. the cooling process is slower here. 6 Experiments . so the column loses condensate.10/2009 CE 600 CONTINUOUS RECTIFICATION The reaction of the temperatures in the column and column head is rapid. Barsbüttel. the differential pressure in the column is reduced roughly twice as fast. Germany 10/2009 Compared to the corresponding profile in the batch experiment (see Fig.3. page 106 shows the decrease in the ethanol mass fraction wE in the top product.N.3. As a result. This decrease corresponds to the result from batch experiment V3 (see chapter 6. To present the change over time in the ethanol concentration in the top and bottom product Fig. page 87).with ethanol/water mixture 113 . As expected. there is another reason for variations here: The measured bottom product flows permanently out of the evaporator. This particular curve trend should not be expected by way of reproducibility in any subsequent repetitions of the experiment. differently concentrated condensate from the column.9 also shows the decrease in the ethanol mass fraction wE in the bottom product. and due to evaporation. Alongside the known inaccuracies of the density measurement.1% of the original mass present (see above). 6. To check the concentrations by means of mass balances Both regard to the mixtures and to ethanol. The intermingling of the evaporator content with the condensate varies in intensity.10/2009 CE 600 CONTINUOUS RECTIFICATION Fig. In the second half of the experiment . 114 6 Experiments . wE steadily decreases in the course of the experiment.in the time band from 17:19 to 17:29 hours .with ethanol/water mixture . these values are of a realistic magnitude. comparison of the two values shows that at the end of the experiment there is still 99.a major decrease in wE is seen. Re 5. This confirms the measured values and the evaluation of the experiment. This discharging bottom product is always a mixture of existing evaporator content and newly arriving. In view of the losses during sampling and transfer. . T ≤ 25°C) Sieve plate column: Øxh Material: Number of plates: 50 x 765 mm Stainless steel 8 Packed column: Øxh Material Packing Material Øxh 50 x 765 mm Stainless steel Raschig rings Soda glass 4 x 4 mm Evaporator: Heating power Capacity Minimum fill Feed pump: 3 L Capacity approx.10/2009 CE 600 CONTINUOUS RECTIFICATION 7 Appendix 7. 0..0 kW max.N.. G.U.5 bar g.1 Technical data Overall unit: lxwxh: 1300 x 750 x 2300 mm Weight: approx.400 ml/min Internal electrical supply 24 VDC Temperature sensors T1 ... T16 : Pt100 Differential pressure sensor:piezoresistive Experiment mixture: ethanol/water 7 Appendix 4. see rating plate Cooling water flow: min. Germany 10/2009 Optional alternatives. 210 kg Electrical supply: 3 x 400V / 50 Hz All rights reserved..150 °C 0 ...25 bar ~ 25 : 75 %m 115 . 0. 10 L 0. Barsbüttel.T. 400 L/h In-house water supply (p ≥ 1. Gerätebau. The worksheets can be used to enter self-recorded measurements by hand during experiments.5 ~ 0.1 can be used for experiments from the “Batch” series. 256 MB RAM • Min. 116 7 Appendix .2 is intended for experiments in the “Continuous” series.10/2009 CE 600 7.2 CONTINUOUS RECTIFICATION Volumes: Feed tanks Bottom product tank Top product tank Phase separation tank Solvent tank ~5 ~5 ~ 1. 1 GHz • Min.5 ~ 0. 1024 x 768 pixels.9 L L L L L Data acquisition: USB communication Program environment: LAB-VIEW Runtime System requirements: • PC with Pentium IV processor. 250 MB available memory on hard disk • 1 x USB port • Graphics card resolution min. True Color • Windows 2000 / XP / Vista Worksheets The following pages set out a series of worksheets. The “Batch” worksheet in Tab. 7. The “Continuous” worksheet in Tab. 7. pr.All rights reserved. 1. B.pr. from Evap.T.pr. Evaluation 10/2009 Date: CE 600 7 Appendix Experiment no.pr. T. ----- T. B.. Fill feed tank..U. 7. Evap: Evaporator Tab.pr. Gerätebau. 2.. wE L g %m ----- T.pr.: Top product.pr. Barsbüttel. G. Individual masses in g Key: T. Germany 10/2009 Participants: Measurement Clock Start. mixture. mixture ----- End.. B.. ----- T. 3. Evap Mass Density net Temperature g °C kg/L Level Comments Mass Mass fraction in Evap net Ethanol.: 117 . Individual masses in g End. ----- ----- End. Evap --------- ----- Measurement Start.N.1 “Batch” worksheet for self-recorded measurements in the “Batch” experiment series ----- CONTINUOUS RECTIFICATION Product/measurement no.: Bottom product.pr.. B.: Top product. T. from Evap. B. mixture ----- ----- ----- End.: Bottom product. from Evap ----- ----Measurement Start.pr..2 “Continuous” worksheet for self-recorded measurements in the “Continuous” experiment series CONTINUOUS RECTIFICATION Start.pr.. wE L g %m ----------------------------------------- ----- End. Evap: Evaporator Tab. Density net Temperature g °C kg/L Level Comments Mass Mass fraction in Evap net Ethanol.pr.: .. mixture. Individual masses in g 7 Appendix End.pr. mixture ----- ----- ----- End.pr. 7.pr. B. Individual masses in g Key: T. Fill feed tank. Fill feed tank.. Evap Mass Evaluation 10/2009 Date: CE 600 118 Experiment no. B. Individual masses in g Start.Participants: Measurement Clock Product/measurement no. s T Temperature °C V · V Volume L Volumetric flow L/h w Mass fraction %m wE Ethanol mass fraction %m x1 Molar fraction in the liquid mixture % y1 Molar fraction in the steam % ρ Density kg/L.2 7 Appendix B. Gerätebau.10/2009 All rights reserved. Germany 10/2009 CE 600 CONTINUOUS RECTIFICATION 7. mbar Pel Electrical Power Output kW R Reflux ratio % t Time min.pr. kg mE Ethanol mass g.3.N.1 Abbreviations used 7.tank Bottom product tank Evap Evaporator HTU Height of Transfer Unit LSL Level Switch Low NTU Number of Transfer Units Pd Packed column SP Sieve plate column T.pr. kg p pressure bar.3 Abbreviations and symbols 7.T. mixture mass g. kg/m³ 119 .pr. G.tank: Top product tank Symbols used f Frequency Hz m Mass. Bottom product B.3. Barsbüttel. Top product T.U.pr. 10/2009 CE 600 120 CONTINUOUS RECTIFICATION 7 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39. . . . . . . . . . . . . . . . . . . . . 8. . . . . . . . . . . . 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Barsbüttel. . . . . . . 1 Distillation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .U. . . . . . . . . . . . . . . . . . . . . . . . 24 E Evaporator . . . . . . . . . . . . . . . 29 Azeotropic rectification . . . . . . . . . 49 Bottom product . . . . . . . . reverse flow . . . . . . . . . . . . . . . .10/2009 CE 600 8 CONTINUOUS RECTIFICATION Index A Areometer . . . . . . . . . . . . 115 Experiment series . . . . . . . . 68 Continuous worksheet . . . . . .T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Curve of equilibrium . . Germany 10/2009 B Batch experiment series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 8 Index 121 . . . . . . . . . 22 Continuous experiment series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. . . . . . . . . . . . . . . 90 Density of ethanol/water mixture . . . . . . . . . . . . . . . . . . . 9. . . . . . . . . . . 14. . 8. . . 25 Bottom heat exchanger . . . . . . . . . . . . 21 D Data acquisition . . . . . . . . . 44. . . . . . . . . . . . . . . . . . . . . . . . 90 Automatic mode . . . . . . . . . . . . . . . . . . . . . . 65 Batch worksheet . . . . . . . . . . . . . . . . . . . 53 Distillate . . . . . . . . . . . . . . . 8. . . . . . . . . . . . . . 27. . . . . . . . . 97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Azeotropic mixture . . . . . . . . . 48 C CE 600 process diagram . . . . . . . G. . . . . . . 61 Condenser . . . . . . 30 All rights reserved. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Continuous rectification . . . . . . . . . . . . 24 Column differential pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Distillation . 14 Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73. . . . . . 57. . . . . . . . . . . . . . 9. Gerätebau. . . . . 65 Batch rectification . . . . . . . . . . . . . . . 28. . . 119 Density measurement . . . . . . . . . 117 Bottom . . . . . . . . .N. . . . . . . . . . . . . . . . . . . . . . . . 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 N NTU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Feed tank . . . . . . . 97 Measurement series . . . . . . . . . . . . . . . . . . . . . . . . .10/2009 CE 600 CONTINUOUS RECTIFICATION F Feed . . . . . . 16. . . . . . . . . . . . . . 8. . . . . . . . . . . . . . . . . 116 122 8 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Packed column . . . . . . . . . . . . . . 57 Measured data field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Measured value file . . . . . . . . . . . . . . . . . . . . . 16 Measured data record . . . . . . . . . . 43 H HTU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 P Packed bed . . 11 M Mass balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Level switch . . . . . . 73. . . . . . . . 30. . . . . 26 I Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9. . . . . . . . . . . . . . . . . . . 73. . . . . . . . 22 G Glass filter pump . 25. . . . 61 Multi-stage distillation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Mass fraction . . . 9 Feed pump . . . . . . . . . . 16. . . . . . . . . . . . . . . . . . . 16 Method of operation of the unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24. . . . . . . . . . . . . . . 90. . . . 115 Phase separation tank . . . . . . . 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Fractional distillation . . . . . . . . . . . . . . . . 8. . . . . . . . . . . . . . . . . . . . . . . . 80 L Level . . . . . . . . . . . . . . . . . 26 V Vacuum distillation . . . . . . . . . Barsbüttel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . G. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 8 Index 123 . . . . .10/2009 CE 600 CONTINUOUS RECTIFICATION R Rectification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N. . . . . . . . . . . . . . . . Gerätebau. . . . . . . . . . . . . . Germany 10/2009 S Sieve plate . . . . . . . . . . . . . 35 Sieve plate column . . 22 Volume contraction . . . . . . . . 22 Reverse flow distillation . . . . . . . . . . . . 59 T Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Theoretical transfer units . . . . . . . . . . . . 25. . . . . . . 1. . . . . . . . . . . . . . . . . . . . . . . . 115 Spontaneous experiments . . . . . . . . . . . . . . . 24 Reflux ratio R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 All rights reserved. . . . . 24 Reflux . . . . .U. . 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 W Worksheets . . . . . . . . . . . . . . . . . . . . . . . 26 Residue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34. . . . . . . . . . . . . . . . . . 10/2009 CE 600 124 CONTINUOUS RECTIFICATION 8 Index .