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API® TECHNICAL DATA BOOK7th Edition CHAPTER 3 PETROLEUM FRACTION DISTILLATION INTERCONVERSIONS Revised Chapter 3 to the Fifth Edition (1992) and Seventh Edition (2005) © 2005, The American Petroleum Institute and EPCON International - All Rights Reserved API TECHNICAL DATA BOOK Index Chapter 3 – Petroleum Fraction Distillation Interconversions Preface ........................................................................................................................................................................ iii Introduction .................................................................................................................................................................1 Figure 3-0.1 – Typical ASTM D86 and Simulated Distillation Curves for a Petroleum Fraction.......................................... 1 Figure 3-0.2 – ASTM, True Boiling Point, and Equilibrium Flash Vaporization Distillation Curves for a Naphtha-Kerosine Blend ...................................................................................................................................................................................... 2 Figure 3-0.3 – Distillation Conversion Routes ....................................................................................................................... 3 Table 3-0.4 – Summary of Correlations for Converting Distillation Data.............................................................................. 4 Computer Methods......................................................................................................................................................5 ASTM, True Boiling Point and Simulated Distillation Relationships.....................................................................6 Procedure 3A1.1 – Interconversion of ASTM D86-TBP Distillations at Atmospheric Pressure............................................ 6 Figure 3A2.1 – Subatmospheric ASTM Distillation and True Boiling Point Distillation Relationship ................................. 9 Procedure 3A3.1 – Conversion of Standard (ASTM D2887) to True Boiling Point Distillation at Atmospheric Pressure.. 11 Procedure 3A3.2 – Conversion of Simulated (ASTM D2887) to ASTM D86 Distillation at Atmospheric Pressure........... 14 Procedure 3A4.1 – Interconversion of Distillation Data for Petroleum Fractions at Subatmospheric Pressures.................. 17 Bibliography...............................................................................................................................................................19 3 - ii © 2005, The American Petroleum Institute and EPCON International - All Rights Reserved 7-2005 Ravicz of Chevron Research and Technology Company. 7-2005 © 2005. continued interest has led to the development of new analytical correlations for conversion of various distillation data. Chair.. Kramer of Amoco Oil Company. and Peter Nick of Unocal. The chapter coordinating committee for the Technical Data Committee was Arthur E. Daubert assisted by Nancy Crane DAubert. Ann Arbor. Dale Embry of Phillips Petroleum Company. Inc.iii . Sheldon J. The majority of work on this chapter was carried out by Thomas E. During the past two years.All Rights Reserved 3 . together with the rationale for inclusion of the procedures in this chapter are available in Documentation Report No.API TECHNICAL DATA BOOK Preface Chapter 3 – Petroleum Fraction Distillation Interconversions (1994) The subject of distillation has been of continuing concern in the design and operation of petroleum refineries and related industries. 3-93 available from University Microfilms. The American Petroleum Institute and EPCON International . Michigan. Detailed results of the methods tested and developed in the course of this work. Most of the procedures for inter-conversion of various distillation data in the previous editions had been developed in the 1940s and 1950s. iv © 2005. The American Petroleum Institute and EPCON International .All Rights Reserved 7-2005 .API TECHNICAL DATA BOOK 3 . gas oils. Temperatures are measured with a thermocouple. The American Petroleum Institute and EPCON International . This method is applicable to all petroleum fractions with a final boiling point of 1000 F or less at atmospheric pressure. absolute. D 1160. ASTM D1160 distillations are plotted in volume percent. ASTM distillations are more widely used than TBP distillations because the former are simpler. Figure 3-0. An exposed thermometer is used. It is a gas chromatographic method otherwise similar to D2887. Both are batch distillations. aviation gasoline’s. Although a function of chemical composition. and consistent method to describe the boiling range of a hydrocarbon fraction unambiguously. the amount and severity of thermal cracking increase with increasing boiling point. reproducible. ASTM D86 distillations are plotted in volume percent. which do not exceed an atmospheric pressure final boiling point of 500 F.1 shows a typical relation between ASTM D86 and ASTM D2887 distillations for a petroleum fraction. ASTM distillations are standardized. The 7-2005 method is a form of true boiling point distillation for any petroleum mixture boiling above light naphtha’s and mixtures with final boiling points below 750 F. contact time. naphtha’s. pressure and temperature. which differ mainly in the degree of fractionation obtained during the distillation. ASTM Method D2892: This method is used for distillation of stabilized crude petroleum defined as having a Reid vapor pressure less than 12 psi. and similar petroleum products.All Rights Reserved 3-1 . It is carried out at pressures between 1 mm Hg and 50 mm Hg. This difference is usually termed "loss" and is generally thought of as volatile components of the charge. ASTM Method D2887: Simulated distillation (SD) by gas chromatography appears to be the most simple.1 – Typical ASTM D86 and Simulated Distillation Curves for a Petroleum Fraction © 2005. and require only approximately one-tenth as much time. which have not been recondensed. It is carried out at atmospheric pressure. Simulated distillations are plotted in weight percent. require less sample. The method is also limited to samples having an initial boiling point of at least 100 F. For preparation of an ASTM distillation for conversion to a TBP distillation. No correction for cracking is now recommended. ASTM D86 and D1160 distillations are run in an Engler flask. Early editions of this chapter included a correction for cracking for observed ASTM D86 temperatures above 475 F. aviation turbine fuels. kerosene’s. No packing is employed. When heated. Results are reported in volume percent. and reflux results only from heat losses through the neck of the flask. Figure 3-0. less expensive. and temperatures are reported without stem corrections. TBP distillations vary appreciably in procedure and apparatus. It employs a fractionating column of 14-18 theoretical stages operated at a reflux ratio of 5. ASTM distillation methods in use today are: ASTM Method D86: This method is used for the distillation of motor gasoline’s. ASTM Method D1160: This method is used for heavy petroleum products. petroleum fractions undergo thermal cracking. and D2892 distillations there may be a residue left in the distillation equipment as well as a difference between the volume of the original charge and the sum of the distillate and residue. ASTM Method D3710: This method is used to determine the boiling range distribution of gasolines. In ASTM D86. the percent distilled at the reported temperature is the sum of the distillate collected and the loss. distillate fuel oils. which can be vaporized partially or completely at a maximum liquid temperature of 750 F at absolute pressures down to 1 mm Hg and condensed at the pressures of the test.API TECHNICAL DATA BOOK Introduction Chapter 3 – Petroleum Fraction Distillation Interconversions (1994) ASTM and true boiling point (TBP) analytical distillations are used to define the volatility characteristics of petroleum fractions and other complex mixtures. In addition. and SD relations.2 also shows the EFV curves of a naphtha-kerosene blend at atmospheric and several super atmospheric pressures compared to ASTM D86 and TBP distillations. The lack of use of a standardized apparatus and operational procedure is a disadvantage. at a constant pressure. Normally. 5 to 1 or greater).. Each point on the EFV curve represents a separate equilibrium experiment. The number of equilibrium experiments needed to define all portions of the EFV curve varies with the shape of the curve. A TBP curve is also shown in Figure 3-0. A schematic diagram of the interconversion procedures is shown in Figure 3-0.All Rights Reserved 7-2005 . Thus. which included many components and exhibited smooth distillation curves. Careful study of Figure 3-0. Correlations in this chapter are empirical in nature and are arranged according to the various pairs between ASTM.3 and Table 3-0. Consult the Comments on each Procedure for the accuracy of each method before use. The EFV curve is a plot of temperature against percent by volume of liquid distilled. all predicted distillation curves are of the correct shape. The tedious procedures necessary to obtain experimental EFV data have made this type experiment quite rare at this time. but the variations between various laboratories are small because a close approach to perfect separation by boiling point is usually achieved.2 for comparison with an ASTM D86 distillation. Expected average errors are given in the Comment. Correlations are summarized in Table 3-0. and SD data on the same fractions are not sufficiently precise or consistent to develop accurate correlations. the existing ASTM. TBP. correlations involving.1 (Step 1) allows interconversion between ASTM D86 and TBP distillations. The high degree of fractionation in these distillations gives accurate component distributions for mixtures. The narrative below describes the procedures to be used in each case. The American Petroleum Institute and EPCON International . Because of a lack of standardization and other inherent inadequacies in the methods.API TECHNICAL DATA BOOK Introduction Chapter 3 – Petroleum Fraction Distillation Interconversions (1994) TBP distillations are performed in columns with 15 to 100 theoretical plates at relatively high reflux ratios (i.4.2 – ASTM. Users are emphatically cautioned against relying heavily on results obtained from these correlations.3. Section 3A1 Section 3A2 Section 3A3 Section 3A4 Figure 3-0. and Equilibrium Flash Vaporization Distillation Curves for a Naphtha-Kerosine Blend An equilibrium flash vaporization is an experiment carried out at constant pressure to determine the temperature-volume percent distilled relation. Figure 3-0. True Boiling Point.4 gives the method(s) to be used for each conversion. 3-2 ASTM-TBP (Atmospheric) ASTM-TBP (Subatmospheric) SD-TBP-ASTM (Atmospheric) Interconversions at Subatmospheric Pressures Use of Procedures Procedures in this chapter are interconnected and are in most respects consistent. It should be noted that in some cases alternative paths are possible. at least five such experiments are required. TBP. © 2005.e. EFV have been eliminated from this chapter. The correlations of this chapter were developed using data for hydrocarbon stocks and fractions. Procedure 3A1. The correlations do not apply to mixtures of few compounds with widely different boiling points. 1 3A3.1 3A3. The American Petroleum Institute and EPCON International .API TECHNICAL DATA BOOK Figure 3-0.2 3A4.All Rights Reserved 3-3 .) P R I M A R Y 4 ASTM D86 3 R O U T E 760 mm 1 TBP 760 mm 5 5 TBP TBP 5 Subatmospheric 10 mm 2 ASTM D1160 ASTM D1160 5 Subatmospheric 10 mm 5 ASTM D1160 Reported at 760 mm Step 1 2 3 4 5 7-2005 Procedure 3A1.1 3A2.1 © 2005.3 – Distillation Conversion Routes (1994) ASTM D2887/D3710 SIMULATED DISTILLATION (GAS CHROM. This method is only recommended for development of a TBP distillation curve if neither an ASTM D86 or simulated distillation are available as the curve. They were developed from kerosene. 3-0. 5.1 (Step 2) allows conversion of ASTM D1160 to TBP distillations at 10 mm mercury total pressure after which Procedure 3A4. Note: A report which documents the basis upon which the material in all editions of this chapter was selected has been published by the American Petroleum Institute as Documentation Reports No. 2.1. The American Petroleum Institute and EPCON International . Procedure 3A3. 5 5. 3-86. 3-93. All data used for development of prediction methods are referenced in these reports. No.4 – Summary of Correlations for Converting Distillation Data Data Available Data Desired Pressure mm Hg Type ASTM D2887 (SD) ASTM D86 ASTM D1160 ASTM D1160 ASTM D1160 TBP ASTM D2887 (SD) ASTM D1160 ASTM D1160 ASTM D1160 ASTM D1160 760 760 10 10 10 10 760 1 1 100 100 Type ASTM D86 TBP TBP TBP ASTM D86 TBP TBP TBP ASTM D86 TBP ASTM D86 Pressure mmHg Conversion Method Steps in Fig. 3-4 © 2005. Many in the industry use D2887 directly as a TBP input for calculations and simulations. 2. and diesel data. 1 5. 1 5 3 5. D2887 was developed to be equivalent to a TBP distillation. was not able to be verified since insufficient experimental data were available. Table 3-0. and No. 1 Note: All ASTM D86 temperatures at 760 mm Hg are observed values.2 (Step 4) relates ASTM D2887 (Simulated) and ASTM D86 distillations with accuracy as given in the Comments. This conversion route should not be used for fractions with D86 distillation temperatures above 600 F.All Rights Reserved 7-2005 . jet fuel. 5. 2. 5 5. A computer method for flash calculations and estimation of equilibrium K-Values for petroleum fractions using a modified Soave-Redlich-Kwong (6) equation of state is included in Chapter 8. while probably more reproducible than ASTM and TBP data. ASTM has developed two procedures for conversion of D2887 data to D86 distillations. 5. These are documented in D2887-04a. Figure 3A2. 2. Equilibrium flash data.1 (Step 5) can be used to convert the TBP to (1994) atmospheric pressure. 2. 3-66. The conversion of Simulated to TBP distillations can also be carried out in two steps (4 and 1) with little degradation of the prediction.3 760 760 10 760 760 760 760 760 760 760 760 4 1 2 2. 5 2. See discussion in Procedure 3A3. are obtained using different types of apparatus and many variations in procedure.1 (Step 3) allows direct interconversion of ASTM D2887 (Simulated) and TBP distillations with excellent accuracy as shown in the Comments. though reasonably shaped.API TECHNICAL DATA BOOK Introduction Chapter 3 – Petroleum Fraction Distillation Interconversions Procedure 3A3. 2 3A3.All Rights Reserved 3-5 .1 Distillation Interconversions Distillation Interconversions 3A3.1 Description Interconversion of ASTM D86-TBP Distillations at Atmospheric Pressure Conversion of Standard (ASTM D2887) to True Boiling Point Distillation at Atmospheric Pressure Conversion of Simulated (ASTM D2887) to ASTM D86 Distillation at Atmospheric Pressure Interconversion of Distillation Data for Petroleum Fractions at Subatmospheric Pressures © 2005.1 3A4. The American Petroleum Institute and EPCON International .API TECHNICAL DATA BOOK Computer Methods Chapter 3 – Petroleum Fraction Distillation Interconversions (2005) Program 7-2005 Procedure Distillation Interconversions Distillation Interconversions 3A1. degrees Fahrenheit.82002 0. TBP (50) = 0.1-4) Similarly. TBP (0) = TBP (50) -Y4 -Y5 -Y6 TBP (10) = TBP (50) -Y4 -Y5 TBP (30) = TBP (50) -Y4 TBP (70) = TBP (50) + Y3 TBP (90) = TBP (50) + Y3 + Y2 TBP(100) = TBP (50) + Y3 + Y2 + Y1 (3A1.71644 0.1-1) to calculate the TBP distillation temperature at 50% distilled. and all equations (3A1. add or subtract the proper difference (s) from the predicted 50% true boiling point temperature.75497 0.1-1) Where: TBP (50) = true boiling point distillation temperature at 50 volume percent distilled. reverse the procedure.30% 30% . To determine the ASTM D86 distillation temperatures from the TBP distillation temperatures.0% A 0. To determine the difference between adjacent cut points. equation (3A1. Step 3: Use equation(s) (3A1.10% 10% . described as follows.90% 90% .1-3) Procedure Step 1: Use equation (3A1.API TECHNICAL DATA BOOK ASTM.4012 B 1. i 1 2 3 4 5 6 Cut Point Range 100% .0419 2. use the following equation: Yi = AX iB (3A1. degrees F A.1 – Interconversion of ASTM D86-TBP Distillations at Atmospheric Pressure (1994) Discussion The following equation is used to convert an ASTM D86 distillation 50% point temperature to a true boiling point distillation 50% point temperature.0258 (3A1.All Rights Reserved 7-2005 . True Boiling Point and Simulated Distillation Relationships Procedure 3A1.80076 0. degrees F Xi = observed difference in ASTM D86 distillation temperature between two cut points.1-2) to calculate necessary TBP differences.50% 50% .1-2) Where: Yi = difference in true boiling point distillation temperature between two cut points. Step 2: Use equation (3A1.0305 4.1-2) can be reversed.87180 (ASTM D86 (50)) 1. (F) 100 150 250 250 100 To determine the true boiling point temperature at any percent distilled. ASTM D86 (50) = observed ASTM D86 distillation temperature at 50 volume percent distilled.1-3) can be modified by changing TBP to ASTM 3-6 © 2005.60244 Maximum Allowable Xi. The American Petroleum Institute and EPCON International . degrees Fahrenheit.5282 3.1-1) becomes ( ASTM D86 (50) ) = exp ⎡ ln (TBP (50) / 0. B = constants varying for cut point ranges.6606 0. all equations (3A1.9004 7.1-3) to calculate desired TBP distillation temperatures.87180) ⎤ ⎢⎣ ⎥⎦ 1.70% 70% .0258 (3A1.11798 3. Thus. the correlation extrapolates well to fractions with ASTM 50% point temperatures up to 600 F. although fewer points were available at the 0 and 100% points. . .80076 7-2005 © 2005. F .1 70 5. . . . 10 ASTM D86 temperature. . In addition. values for these points should be taken as rough approximations. . . . while bias error sums the actual values of the differences. .8 30 5.1-1 and 3A1. .6 1. .8 F 10 9. . . Special Comment This method was derived from all data available to the project and was judged to be the most appropriate form for interconversion among the various types of distillations. F . initial and final boiling point data are scarce and inaccurate.9 F -7. users may wish to check the correlation with their proprietary data before using it.2F Using equation (3A1. . .1 (1994) Purpose The purpose of this procedure is to predict a TBP distillation at atmospheric pressure from an ASTM D86 distillation or the reverse by hand or by computer. 321 30 380 371 50 404 409 70 433 447 90 469 491 Using equation (3A1. As additional data become available. . . Reliability Differences between the estimated and experimental TBP values at various volume % distilled points are given below. Care should be taken in extrapolating above this point.0 Seventy-one sets of data were used in development.API TECHNICAL DATA BOOK Comments on Procedure 3A1.7 -0.7 -0. all derivations were carried out on fractions having an ASTM 50% point temperature of 480 F and below.1 2. . .1-2) at the 30% point Y4 = 3. 350 TBP temperature. Volume percent distilled .2 4. .4 50 4. .1-2) can easily be improved. . . TBP (predicted) – TBP (experimental) Volume % Distilled Average Bias 0 21.All Rights Reserved 3-7 . The American Petroleum Institute and EPCON International .0 -1. the constants in equations (3A1.3 100 4. . . The experimental TBP temperatures are given for comparison with the predicted temperatures. .1 90 7.0305 [X4]0. . Limitations Because experimental data on higher boiling fractions are quite scattered. . . . .0258 = 411.87180 (404)1. . However. Example Estimate the atmospheric TBP distillation temperatures for a petroleum fraction having the experimental ASTM D86 distillation temperatures given in the following table. . Literature Source This method was developed by the API TECH DATA BOOK Project at The Pennsylvania State University. . In addition. Average error is defined as the sum of the absolute values of the differences between predicted and experimental temperatures divided by the number of data points.1-1) TBP (50) = 0. Thus. 6 F TBP(70) = 411.7 F The reverse conversion from experimental TBP temperatures to ASTM D86 temperatures is illustrated only for the 50% and 30% points.6 F Similarly.9° F 1.5 = 496.380 = 24 F therefore.0305) ⎤ X 4 = exp ⎢ ⎥ = 23. ⎡ ln(Y4 / 3.1 (Continued) (1994) Where: X4 = 404 .6 = 372.6 – 56.9 – 23.80076 ⎦ Where: Y4 = 409 – 371 = 38 F (3) ASTM D86(30) = ASTM D86(50)-X4 = 401.1-2) and (3A1.0258 ⎣ ⎦ (2) Use equation (3A1. ⎡ ln(409 / 0. Y2 = 45. Y4= 38.2 – 38.0 = 451.1-3) at the 30% point TBP(30) = TBP(50) – Y4 = 411.0 = 316.4 F 3-8 © 2005.1-3) at the other cut points.1-2) to determine the 50 to 30% ASTM increment.2 + 40.2 F TBP(90) = 451.0 Y5 = 56.87180) ⎤ ASTM − D86(50) = exp ⎢ ⎥ = 401. using equation (3A1. The American Petroleum Institute and EPCON International .6 F Using equation (3A1.5 Y3 = 40. (1) Use equation (3A1.API TECHNICAL DATA BOOK Comments on Procedure 3A1.0 TBP(10) = 372.1-4) to convert the experimental TBP 50% point temperature.5° F ⎣ 0.All Rights Reserved 7-2005 .5 = 378.2 + 45. 1 – Subatmospheric ASTM Distillation and True Boiling Point Distillation Relationship (1994) 7-2005 © 2005. The American Petroleum Institute and EPCON International .All Rights Reserved 3-9 .API TECHNICAL DATA BOOK Figure 3A2. .1. Example Estimate the TBP curve at 10 mm Hg for a petroleum fraction having the following ASTM D 1160 distillation temperatures at 10 mm Hg: Distillation. 10 Temperature. 300 30 400 50 475 70 550 90 650 First. Literature Source Adapted from Edmister and Okamoto. copyrighted in 1959 by Gulf Publishing Company. . deg F . Houston.1) (Degrees Fahrenheit) 106 82 75 100 The TBP temperatures are then calculated. . 3A2. . find the temperature differences for each segment of the TBP curve at 10 mm Hg: Segment of Curve (Percent by volume) 10 mm Hg ASTM D 1160 Temperature Difference (Degrees Fahrenheit) 10 to 30 30 to 50 50 to 70 70 to 90 100 75 75 100 10 mm Hg TBP Temperature Difference from (Fig 3A2. . Reliability No quantitative evaluation of the correlation could be made because of lack of data.10 70-percent temperature = 475 + 75 = 550 F 90-percent temperature = 550 + 100 = 650 F © 2005. the 50-percent temperature is 475 F: 30-percent temperature = 475 – 82 = 393 F 10-percent temperature = 393 –106 = 287 F 3 . . The ASTM D 1160 and TBP distillation 50-percent temperatures are assumed to be equal at 10 mm Hg absolute pressure.API TECHNICAL DATA BOOK Comments on Figure 3A2. The American Petroleum Institute and EPCON International . from Fig. The original reference indicates that temperatures from this method will be within 25 F of the actual values. Special Comment The ASTM D 1160 and TBP 50-percent points at 10 mm Hg are assumed to be equal. Refiner 38 [9] 271(1959). percent by volume . .All Rights Reserved 7-2005 . . Here. . . . . Texas. Petrol. .1 (1994) Purpose This figure relates ASTM D 1160 and TBP distillation data at 10 mm Hg absolute pressure. D = constants varying for cut point ranges. described as follows.1 – Conversion of Standard (ASTM D2887) to True Boiling Point Distillation at Atmospheric Pressure (1994) Discussion The true boiling point temperature at 50 volume percent distilled is taken to be equal to the simulated distillation temperature at 50 weight percent distilled.All Rights Reserved 3 .W6 -W7 TBP (10) = TBP (50) . To determine the difference between adjacent cut points.90% 3 90% .1-2) to calculate necessary TBP differences. use the following equation. The American Petroleum Institute and EPCON International . Step 3: Use equations(s) (3A3.1-1) to calculate the TBP at the 50% distilled point. Wi = CVi D (3A3.1-1) Where: TBP (50) = true boiling point temperature at 50 volume percent distilled. 7-2005 © 2005.011903 0. Step 2: Use equation (3A3.1-3) to calculate desired TBP temperatures.95%* 2 95% . degrees Fahrenheit.1-3) Procedure Step 1: Use equation (3A3.05342 0.0253 1.8723 1.1-2) Where: Wi = true boiling point temperature difference between two cut points.W6 TBP (30) = TBP (50) .30% 6 30% -10% 7 10% .31531 0. TBP (5) = TBP (50) .W5 .3975 1.50% 5 50% . C. SD (50) = simulated distillation temperature at 50 weight percent distilled.11 .9733 0.5% *approximate-use with care C 0. TBP (50) = SD (50) (3A3. (F) 30 40 75 75 75 75 40 To determine the true boiling point temperature at any percent distilled.W5 . degrees Fahrenheit.2938 1.97476 0.W5 TBP (70) = TBP (50) + W4 TBP (90) = TBP (50) + W4 + W3 TBP (95) = TBP (50) + W4 + W3 + W2 TBP (100) = TBP (50) + W4 + W3 + W2 + W1 (3A3. degrees Fahrenheit. Vi = simulated distillation temperature difference between two cut points. Cut Point i Range 1 100% .19861 0.15779 D 1.API TECHNICAL DATA BOOK Procedure 3A3.02172 0.4296 Approximate Maximum Vi. add or subtract the proper difference(s) from the predicted 50% true boiling point temperature. degrees Fahrenheit.6988 2.70% 4 70% . 1 -2. Conversion of Simulated to TBP Distillation Comparison of Two-Step Procedure with OneStep Procedure-Error Analysis Conversion of SD to ASTM D86 by step 4 followed by Conversion of Calculated ASTM D86 to TBP by step 1 Conversion of SD to TBP by step 3 Errors.4 -8.3 1. Also. values for these points should only be taken as rough approximations. Although the correlation extrapolates well.4 9.3 12. use of the resulting temperature-% distilled data outside the limits is not encouraged.0 12.3.0 -9.6 8. carried out on 19 sets of data for which ASTM D86.0 Twenty-one data sets were used in development of this procedure. This method should be limited to fractions boiling below 600 F.7 0.0 11.5 19.0 4.0 50 9. users may wish to check the correlation with their proprietary data before using it.3 5. The table below shows an error analysis. TBP. The American Petroleum Institute and EPCON International .7 12.2 30 12.1-2) can easily be improved.TBP (experimental) % Distilled Average Bias 5 21.1 0. as the data scatter is so great that the correlation is meaningless.12 _ Data points Ave Bias Ave Bias 18 19 19 19 19 19 8 32.6 l00 8.1 F 10 19. The initial boiling point is not included. Reliability Differences between the predicted and experimental TBP temperatures at various %-distilled points are given below.6 11.1 (1994) Purpose The purpose of this procedure is to predict a TBP distillation at atmospheric pressure from a simulated distillation by hand or by computer.1 -8. A two-step procedure giving essentially equivalent results for materials with TBP temperatures below 600 F consists of step 4 followed by step 1 of Figure 3-0.6 0. Special Comment This method was derived from all data available to the project and was judged to be the most appropriate form for interconversion among various types of distillations.3 3.6 -1. and SD were available.4 90 12.API TECHNICAL DATA BOOK Comments on Procedure 3A3.6 70 11.2 8.All Rights Reserved 7-2005 . F % Distilled 0 10 30 50 70 90 100 3 . as final boiling point data are not generally accurate. which confirms this conclusion.3 2.0 -1.7 F 2.4 7. In addition.0 © 2005.7 0. TBP (predicted) .2 1. except at the 100% point where only 8 sets were available.0 0.2 -2.6 -1.4 95 12. Limitations Data sets with TBP 50% points between 250 and 700 F were used in deriving this correlation. the constants in equations (3A3.4 -1. As additional data become available.3 9.6 -29. F Errors. . . . .6 = 332. . using equations (3A3.1 F = 336.W5 = 336 .1-3) at the 30% point TBP (30) = TBP . . .1-2) and (3A3. .6 F = 332.All Rights Reserved 3 . 293 TBP temperature. 5 SD temperature. . .3 F © 2005. % distilled .4 F = 339.1 (Continued) (1994) Literature Source This method was developed by the API Technical Data Book Project at The Pennsylvania State University. . . .5 F W4 = 3. .5 F 7-2005 TBP (95) TBP (90) TBP (70) TBP (10) TBP (5) = 350.6 F W7 = 5. . .5 = 350. 321 10 305 322 30 324 326 50 336 332 70 344 337 90 359 345 95 369 348 Using equation (3A3.4.1-3) at other cut points W2 = 7.8 F = 327.05342[V5]1. . . . .5 = 322. F . .3 = 357. F . Experimental TBP temperatures are given for comparison with the calculated temperatures.5.API TECHNICAL DATA BOOK Comments on Procedure 3A3.3 F W3 = 10. .6988 where V5 = 336 – 324 =12 therefore W5 = 3.6 F W6 = 4.6 F Using equation (3A3.6 = 339. . . The American Petroleum Institute and EPCON International .1 + 7.6 = 327. .4 F Similarly. . .6 + 10. . + 3. Example Estimate the atmospheric TBP distillation temperatures for a petroleum fraction having an experimental simulated distillation as given in the following table.1-2) at the 30% point W5= 0. .1-1) TBP (50) = SD (50) = 336 F Using equation (3A3. . .8 .4 .13 . .3. 2341 100 3 70% .70% 0.65962 100 2 90% .30785 1.2-1) Where: ASTM (50) = ASTM D86 temperature at 50 volume percent distilled. ASTM (50) = 0.07978 1. SD (50) = simulated distillation temperature at 50 weight percent distilled. 3 .5386 100 5 30% . degrees Fahrenheit.10% 0. degrees Fahrenheit.4287 100 4 50% .F = constants varying for cut point ranges.77601 (SD (50))1.0395 (3A3.U6 ASTM (50) .U5 ASTM (50) .90% 2.06069 1. (F) 1 100% .2 – Conversion of Simulated (ASTM D2887) to ASTM D86 Distillation at Atmospheric Pressure (1994) Discussion The ASTM D86 temperature at the 50 volume percent-distilled point may be calculated from the simulated distillation temperature at the 50 weight percent distilled point.2-3) Procedure Step 1: Use equation (3A3. The American Petroleum Institute and EPCON International .5176 150 6 10% .50% 0. degrees Fahrenheit. Approximate Maximum Cut Point Allowable i Range E F Ti.API TECHNICAL DATA BOOK Procedure 3A3.U5 .U4 . E. described as follows.2-3) to calculate desired ASTM D86 temperatures.U4 .All Rights Reserved 7-2005 . ASTM (0) = ASTM (10) = ASTM (30) = ASTM (70) = ASTM (90) = ASTM (100) = ASTM (50) .U4 ASTM (50) + U3 ASTM (50) + U3 + U2 ASTM (50) + U3 + U2 + U1 (3A3.14 © 2005.14862 1. To determine the difference between adjacent cut points. degrees Fahrenheit. Step 3: Use equation(s) (3A3.1259 150 To determine the ASTM D86 temperature at any percent distilled.6029 0.0% 0.2-2) Where: Ui = ASTM D86 distillation temperature difference between two cut points.30% 0. use the following equation. Ti = SD temperature difference between two cut points. U i = ETi F (3A3. Step 2: Use equation (3A3.30470 1.2-2) to calculate necessary ASTM D86 differences.2-1) to calculate the ASTM D86 at the 50% distilled point. add or subtract the proper difference(s) from the predicted 50% ASTM D86 temperature. 3 . .148 = 67.2 (1994) Purpose The purpose of this procedure is to predict ASTM D86 distillation temperature from simulated distillation data by hand or by computer. As additional data become available.1 90 9. Experimental ASTM D86 temperatures are given for comparison with the calculated temperatures. .2-1 and 3A3.2-1) ASTM (50) = 0.8 100 19. As initial and final boiling point data are inaccurate. . .9 50 7.5 -9. . Reliability Differences between the predicted and experimental ASTM D86 temperatures at various %-distilled points are given below. D86 (predicted) – D86 (experimental) % Distilled Average Bias 0 21.2-2) at the 30% point U4 = 0. . . therefore U4 = 51.0 F 10 8.2-3) at the 30% point ASTM (30) = 206. . This procedure can be used for D3710 to D86 conversions. . F . Limitations Data sets with ASTM D86 50% points between 150 and 600 F were used in deriving this correlation.3 F Using equation (3A3.All Rights Reserved 3 .5386 where T4 = 215 . Literature Source This method was developed by the API Technical Data Book Project at The Pennsylvania State University. . . In addition.6 Approximately 125 data sets were used in development.07978 T41 .15 . % distilled . Special Comment This method was derived from all data available to the project and was proven to be the most accurate form for interconversion among all types of distillations. . .1 70 4.51.5 -0. The American Petroleum Institute and EPCON International . 0 SD temperature. but the reliability is not known.5 F 8. F . . . . Some evidence shows errors to be significantly higher above a 600 F boiling point.2 30 5. .5 =154. values for these points are only rough approximations and should not be used for design. .77601(215) 1. . .0395 = 206. 104 10 93 134 30 148 163 50 215 208 70 285 269 90 360 335 100 408 390 Using equation (3A3. . Although the correlation extrapolates well.API TECHNICAL DATA BOOK Comments on Procedure 3A3.5 F Using equation (3A3. . the constants in equations (3A3.3 0. 77 ASTM D86 temperature. .2-2) can easily be improved.6 3.8 F. . . use of the resulting temperature-% distilled data outside the limits is not recommended. . users may wish to check the correlation with their proprietary data before using it.6 -1. Example Estimate the atmospheric ASTM D86 distillation temperature of a petroleum fraction having an experimental simulated distillation as given in the following table.8 < 0. 7-2005 © 2005. 3 + 64.2-3) at other cut points U1 U2 U3 U5 U6 3 .5 F 63. Continued (1994) Similarly.5 F 6.3 F 121.5 ASTM (0) = 128.4 F 64.0 + 33.8 – 26.API TECHNICAL DATA BOOK Comments on Procedure 3A3.4 ASTM (70) = 206.9 = = = = = 367.9 F ASTM (100) = 334.5 ASTM (90) = 270.16 = = = = = 33.4 F © 2005.5 F 334.6 F 128.6 + 63. The American Petroleum Institute and EPCON International .0 F 270.3 – 6.3 ASTM (10) = 154.3 F 26.All Rights Reserved 7-2005 .2-2) and (3A3. using equation (3A3.2. 19.8).17 .1 – Interconversion of Distillation Data for Petroleum Fractions at Subatmospheric Pressures (1994) Discussion The following procedure is recommended to convert ASTM or TBP distillation data between subatmospheric pressures (usually 1. Data at Subatmospheric Pressure Step 1: Assume the Watson K of the petroleum fraction is 12. no Watson K correction is necessary. 7-2005 Data at Atmospheric Pressure Step 1: If the specific gravity and mean average boiling point are known or can be calculated. Otherwise assume K =12. Step 2: Follow Procedure 5A1.API TECHNICAL DATA BOOK Procedure 3A4. Procedure A. The American Petroleum Institute and EPCON International . Step 2: Since the Watson K is set at 12. determine the Watson K from the defining equation (2-0.19.All Rights Reserved 3 . © 2005. 100 mm Hg) and between subatmospheric pressures and atmospheric pressure (760 mm Hg). 10. B. and convert the data using Procedure 5A1. 8 and could be used as an estimate for all fractions distilled at subatmospheric pressure. If the Watson K is taken to be 12.7 Interconvert these data to distillation temperatures at each of 1. In this case. Four experimental TBP distillation data points are: Measured TBP Temperature. This procedure is intended for both desk and computer use.API TECHNICAL DATA BOOK Comments on Procedure 3A4.4° API Saudi Arabian crude for which extensive TBP data are available.20b. assume K = 12 and read results directly from Figure 5A1.18 © 2005. Reliability Reliability is the same as given for Procedure 5A1. mm Hg 760 10 1 TBP Temperature. Limitations Limitations are the same as given for Procedure 5A1. The American Petroleum Institute and EPCON International . Each tabulation slows good consistency. 3 .All Rights Reserved 7-2005 .19. F 450* 218 144 492 252* 175 742 782 463* 498 370 403* _________________ *Experimental values.19. The measured temperature at one pressure can be converted to each of the other two pressures.06 The Watson K for the entire crude. Although it is not necessary in this case.5 40. for the first point: K = (450 + 460) 1/3/ [141. is 11.19. F 450 252 463 403 Pressure.1 (1994) Purpose The purpose of this procedure is to convert petroleum fraction ASTM or TBP distillations from one pressure to another up to atmospheric pressure. note that the actual Watson K is calculable for the first point and could be used with the full Procedure 5A1.5)] = 12.5 + 44.8 26. assuming a MeABP of 617 F. and 760 mm Hg pressure. Example Consider 31. For example. mm Hg 760 10 10 1 Volume % Distilled 30 34 58 62 API Gravity 44.3 24.5/ (131. especially for highly aromatic fractions. larger errors will result. The results are given below: Volume % Distilled 30 34 58 62 Pressure. 10. Houston. “Documentation of the Basis for Selection of the Contents of Chapters 2 and 3 including Portions of Chapters 3. Danner.P.E.C. K. “Applied Hydrocarbon Thermodynamics-Part 13: Equilibrium Flash Vaporization Correlations 7-2005 4.E.. T. W. D. Ann Arbor.. Michigan. Soave. © 2005. The American Petroleum Institute and EPCON International .. Eng.C. T. 4.19 .API TECHNICAL DATA BOOK Bibliography Chapter 3 – Petroleum Fraction Distillation Interconversions (1994) 1. Pollock. Eng. Riazi. 27 1197 (1972).. Documentation Report No. Daubert.. M. 6. Okamoto. for Heavy Oils Under Sub-atmospheric Pressures. University Microfilms. University Microfilms. 2. and 8” in Technical Data Book-Petroleum Refining. G.C... (1961).. Edmister. Gulf Publishing Company. Chem. M. R. “Phase Relations for Petroleum Fractions. 3.. Daubert. Refiner 38 [9] 271 (1959). 133. Edmister. Ann Arbor.K.. Daubert. 2-81. Documentation Report No. Danner. 3-93. Daubert. “Documentation of the Basis for Selection of the Contents of Chapters 2 and 3” in Technical Data Book-Petroleum Refining. Sci.E.R.All Rights Reserved 3 .E. W. 2.” Petrol..K. N.. R. Documentation Report No. Applied Hydrocarbon Thermodynamics. Michigan. University Microfilms. Progr 44 905 (1948).H.” Chem. Michigan. 5. Maslanik. Ann Arbor.3-86. “Documentation of the Basis for Selection of the Contents of Chapter 3” in Technical Data Book-Petroleum Refining. T.