Process Technologies Availability and SelectionCriteria This chapter discusses the available technologies for VCM process and the selected technology of Technik co. based on some criteria. To produce VCM, several technologies were developed around the world. Each technology differs from others by type of feed stocks, numbers of units, and the reactors type. For instance, some technologies use air as a feed to the oxy-chlorination reactor rather than pure oxygen which Technik uses. Therefore, some technologies have been eliminated like Ethyl integrated, PPG, B.F Goodrich, Phone-Poulenc, and Monsanto technology. Technik co. passed through other available technologies (MTC, Toyo Soda, Vinnolit, and Stauffer) to select the best one based on some criteria such as efficiency and economics. 1. Stauff er Technology 2. MTC technology 3. Toyo Soda Technology 4. Vinnolit Technology Technik co. selected hybrid between both Toyo and Vinnolit technologies, since there are many similarities between them. See More B. and Monsanto technology. washed and distilled to remove water. PPG.F Goodrich.Objective This chapter discusses the available technologies for VCM process and the selected technology of Technik co. Stauff er Technology: In the direct chlorination process for Stauffer. Vinnolit. Introduction: To produce VCM. based on some criteria. the reactor product is combined with the crude oxy EDC. Then. passed through other available technologies (MTC. Each technology differs from others by type of feed stocks. Stauffer also offers an oxygen-based oxy process in which the main reactor off-gas. ethylene and chlorine are reacted in the liquid phase to produce a crude product which contains 99. some technologies have been eliminated like Ethyl integrated. Technik co. following condensation of EDC. For instance. light ends and heavy ends. several technologies were developed around the world. Phone-Poulenc. Therefore. numbers of units. and Stauffer) to select the best one based on some criteria such as efficiency and economics. is . some technologies use air as a feed to the oxy-chlorination reactor rather than pure oxygen which Technik uses. Toyo Soda.7% EDC. and the reactors type. In 1987 the name of company changed to Tosoh Corporation.000 people. In the oxy-chlorination section. MTC technology: For the direct chlorination reaction. A small slipstream from the ethylene-rich recycle is purged to an ethylene recovery unit for control of inerts. The heat of the reaction is dissipated with the gaseous EDC exit stream which is condensed externally and sent to purification. The neutralized gas is cooled to condense EDC and water.compressed and recycled to the first oxy reactor. and pure EDC which is cracked to yield VCM. they use oxygen as a fed in the fluidized bed reactor. MTC technology utilizes a boiling liquid process. The VCM purification is similar to the Stauffer technology. The reactor effluent gases quench cooled with circulating EDC followed by caustic neutralization." The parent company was established in 1935 and it's named Toyo Soda. One of the company products is Vinyl Chloride Monomer (VCM) which developed by the oxy-chlorination process. . heavy ends. they split crude EDC into light ends. An excess of ethylene is used to maximize HCl conversion and minimize byproducts. Toyo Soda Technology: About Toyo Soda: "Toyo Corporation is the parent company of a Japanese chemical and specialty products and materials group that comprises 132 companies worldwide and a multiethnic workforce of more than 11. For the EDC purification. The boiling solvent is the product itself. For safety .2 atm and preheated to 160 C." Toyo Soda Process: In the direct chlorination section. The EDC vapor (and by-products) is condensed completely and the liquid stream containing some gases is sent to a knock out drum where all gases disengage and are removed from the top before being sent to gas treatment and disposal.25% v/v) containing by volume 2% O2. The bottom product of knock out drum is almost EDC with some by-products is mixed with crude EDC produced from oxy-chlorination section."This process allowed Tosoh to maintain the largest production capacity of VCM in Japan.1% H2 are reacted in the "boiling liquid" reactor in the presence of FeCl3 catalyst. All feed streams are at 2. The conversion of Cl 2 is 100%. pure ethylene (same source as for direct chlorination). 0. One the Toyo technology advantages is the better quality of EDC produced and economy of energy since the heat of reaction is used to boil-off EDC (at 1 atm and 85 C) and small amounts of byproducts. before being sent to storage in large tanks. there is EDC and catalyst in the reactor vessel).5% N2. at 1 atm. pure oxygen (from a neighboring air plant). In the oxy-chlorination section. 0. EDC (at start-up.15% CO2 and 0. and the recycled HCl (coming from VCM purification section) are fed to the fluidized bed reactor with CuCl2 catalyst supported on Alumina. 100% pure ethylene and brine electrolysis cell chlorine (97. [16] The EDC purification section consists of two distillation columns: a "light ends" column to remove low boiling impurities and a "heavy ends" column to remove higher boiling impurities. The conversion of HCl is 100%. The vapor product is quenched to 35 C and the liquid is sent to a 3 phase separator phase separator where 95% v/v of water initially present and all gases are removed (aqueous stream and gas stream of the 3-phase separator) and sent to waste treatment. These impurities take place as by-products in the 3 reaction sections.reason. by-products and some water is sent to a dehydrator column (azeotropic distillation) to remove water from the organic phase. ethylene and oxygen are not mixed outside the reactor. stored crude EDC is then pumped to the EDC purification section to obtain pure EDC suitable for cracking. all low boiling components are removed as top product at 20 C and sent to waste treatment (these are chlorinated products and can be burnt to produce HCl which can be used to produce low grade hydrochloric acid to adjust pH in water treatment . The bottom stream containing crude EDC is mixed with EDC from the direct chlorination section and recycled EDC from the VCM purification section before being pumped to storage tanks at 35 C. The reaction takes place in the vapor phase at 250 C and 2 atm. Water is removed from the top of the column (because of the azeotrope) and EDC with by-products from the bottom. In the light ends column. The organic stream containing EDC. In the VCM purification section.sections). Pure EDC is pumped to 10 atm and preheated to 220 C before it enters the cracking tubes maintained at 500 C. HCl recycled to the oxy-chlorination reactor after preheated to 160 C and 2. and also to some by-products. The EDC cracking section is made up of a tubular reactor. pure EDC is obtained as top product at 70 C and the bottom product (at 120 C) is a mixture of high boiling chlorinated components which can be mixed with the low boiling by-products to produce hydrochloric acid. and is quenched to 100 C. to undergo decomposition into VCM and HCl. the cooled cracking product stream is fed to a distillation column "HCl column" to recover 100% of HCl at the top of the column at 5 atm and -30 C. It is assumed both columns are 100% efficient.2 atm. The . The cracking reactor effluent emerges at 500 C and 9 atm. Pure EDC is then pumped to the EDC cracking reactor (furnace heated with natural gas fuel). The bottom product is pumped to the heavy ends column at 115 C. In the heavy ends column. The pressure after the direct contact heat exchanger is still 9 atm in order to keep the phase in a liquid state. Pressure in the EDC purification train is maintained at 1 atm throughout. The EDC conversion is limited to 55% to avoid coking of the tubes. arranged in serpentine vertically. VCM is sent to storage (spherical tank). This stream is throttled down to 1 atm and cooled in a heat exchanger to 35 C before being recycled and mixed with EDC from the direct chlorination and oxy-chlorination reactors." Vinnolit Process: The modern Vinnolit process for the production of VCM has many distinctive features. One of these distinctive features is high operational reliability (reliable reaction control…). Vinnolit Technology: About Vinnolit: Vinnolit is one of the most common chemical companies in Europe and worldwide producing EDC. Also.bottom product of HCl column is pumped to the VCM column to recover pure VCM from the top of the column at 10 C and 2 atm. and PVC. it's specialize by high economic efficiency (High yield.25% v/v) containing by . It is a technical leader in specialty PVC. These are recovered at 120 C and 6 atm. "Vinnolit was founded in 1993 as a joint venture of the PVC divisions of Hoechst AG and Wacker Chemie GmbH. in the direct chlorination section pure ethylene and brine electrolysis cell chlorine (97. Columns in the VCM purification train are assumed to be 100% efficient. extremely low pollution levels (low VCM emissions…). For Vinnolit process. VCM. The VCM column bottom product consists of EDC and by-products. low maintenance cost…). Moreover. The catalyst used in boiling reactor is an organic compound to suppress the formation of byproducts and ensure higher selectivity to EDC.15% CO2 and 0. "Thus the Vinnolit direct chlorination process combines the energy efficiency of high temperature chlorination (HTC) with the EDC purity of low temperature chlorination (LTC). hydrogen chloride. The top product (water with small quantities of chlorinated hydrocarbons . The crud EDC sent to the purification and then to the cracking.1% H2 are reacted in a conventional or in a boiling reactor at a temperature between 80120 C and pressure between 1-2. the EDC produced in a fluidized bed reactor by highly exothermic reaction at temperature >200 C between ethylene.5 bars. 0. For the EDC purification section." Produced gases stream quenched and the EDC is condensed with the aid of chilled water in a multi-stage condensation unit."[10] The EDC produced by direct chlorination is directly fed to the thermal cracking without any farther purification. oxygen and complicated inorganic catalyst. In the oxy-chlorination section. all EDC produced from oxychlorination and the recycled EDC from cracking enter the heads column in order to remove the water and lo-boiling ends. 0. "The excellent distribution in the fluidized-bed makes it possible to maintain a constant temperature to ensure low by-product formation and to achieve optimum process control.5% N2.volume 2% O2. The EDC cracking takes place in a cracking furnace heated by fuel. Vinnolit and Toyo have many similarities in energy requirement. environmental impact. and MTC technologies based on some important criteria. the hydrogen chloride is recovered and recycled to the oxy-chlorination section. Any HCl traces removed from VCM in the HCl stripper. economics. "By incorporating a newly developed external EDC pre-evaporation facility. The bottom product of the vacuum column sent to the incineration unit. In the HCl column. HCl and by-products are produced at a temperature >480 C. Stauffer. VCM. The bottom product pumped to the next distillation column "high-boil column" to remove high-boil components and then to the vacuum column to remove more high-boil ends. and HCl stripper. VCM column." The VCM purification section consists of three columns HCl column. Toyo. and environmental impact.and sodium chloride) sent to the waste water treatment. Both of them have low energy consumption due to the utilization of reaction and waste gas heat. safety and . safety. Technologies Comparison: The table below shows the comparison between Vinnolit. which are energy requirement. number of columns affect energy requirement and economics. The top product of the VCM column is pure VCM (HCl content <1 ppm). In fact. the formation of coke in the cracking furnace is considerably reduced. Moreover. safety and environmental. safety. Also. Stauffer and MTC have number of columns more than others.8) Conclusion: . selected hybrid between both Toyo and Vinnolit technologies.5 1. economics cost and safety. therefore the required energy. Table.5 6 Based on these criteria.2. O 2 content < 1%. 2.1: Technologies comparison. where the waste water quantities with EDC/VCM content < 1 ppm.5 2 2 1.5 4. The difference between them was in the economics.5 Requirement Economics Safety Environmental 2 2 2 1. Toyo and Vinnolit consider high safety standard. since there are many similarities between them.5 1 1 1.5 1.environment impact are very important criteria in the technology selection. In other hand. Criteria Toyo Technologies Vinnolit Stauffer MTC Soda /2 /2 /2 Energy /2 2 2 1 1.5 Impact Total /8 8 7. environmental impact will increase. the pollution level is extremely low. since Vinnolit has more columns than Toyo. Technik co. based on many criteria a hybrid between Toyo and Vinnolit technologies selected to be use in Technik co. Some of these technologies are very common like Vinnolit and Toyo. several technologies for VCM process verify around the world.In conclusion. studied all available technologies and eliminated some of them. which didn't match with Technik feed stocks. Finally. . Technik co.