Method for producing 1,2-dichloroethane
(57) Abstract:Usage: raw material of large monomer is vinyl chloride, 1-2-dichloroethane is a solvent with a wide range of properties and raw material for production of other chlorinated solvents (trichloroethylene, perchloroethylene and other ). The inventive process is conducted by the chlorination of ethylene with chlorine in the liquid 1,2-dichloroethane at a temperature of 20 deg. C to the boiling temperature of the reaction mass (84 deg C and above) in the presence of a complex catalyst in an amount of 0.1-2.0 wt.%. As catalysts for use ternary catalyst system comprising complexes of halides of metals such FeCl2, FeCl3, SnCl4, SbCl5with nitrogen donors such as hexamethylphosphorotriamide, pyridine and inhibitors of radical reactions of 2,6-di-tert-butyl-4 methyl phenol, n-NITROPHENOL, 2,2-di(n oksifenil)propane. table 2. The invention relates to a method for producing 1,2-dichloroethane (EDC), used as raw material for one of the most important large-capacity monomer is vinyl chloride, used for the production of polymers and copolymers, EDC is also a solvent with a wide range of properties and raw material for production of other chlorinated m ethylene in the environment EDC at temperatures 20 64oC in the presence of ferric chloride as a catalyst (patent Germany N 2540291, publ. 1977; N 31448450, publ. 1983; U.S. patent N 4072728, publ. 1978).The selectivity for EDC in these conditions is 98 to 99% of the Main disadvantages of these methods are:
the need for cleaning EDC raw from the catalyst and related wastewater;
significant loss of ethylene from the exhaust gases, since the process is conducted at a ratio of chlorine:1 ethylene:1,1 1,2.Known methods for producing EDC chlorination of ethylene with chlorine in the environment of boiling EDC in the presence of 0.06 to 0.60% anhydrous ferric chloride (U.S. patent N 2929852, publ. 1960, N 4172099, publ. 1979; application Germany N 3137513, publ. 1975). The selectivity for EDC in these methods, chlorination is 97%
The main disadvantages of these methods of obtaining the EDC are:
rapid accumulation of high compounds and oligomers (Asmolov) in the reaction mass, which causes deactivation of the catalyst and the waste of raw materials;
the need for private update of the reaction mass in the reactor chlorination due to the accumulation in it of the catalyst, Asmolov and high products.Known methods closest to the proposed us ablatherm pressure or under a pressure of 1.3 - 1.5 ATA in the presence of a catalyst anhydrous tetrachloroferrate alkaline or alkaline-earth metal, or ammonium, or a mixture of iron chloride (III) and salts of alkaline or alkaline-earth metal, or ammonium, and the inhibitor - oxygen (patent USSR N 1277887).The present invention aims to increase the duration of operation of catalytic systems with a high selectivity of the process of chlorination of ethylene to 1,2-dichloroethane.As a catalyst propose to use an integrated system that includes halides of metals FeCl2, FeCl3, SnCl4, SbCl5and nitrogen-containing electron-donating compounds: hexamethylphosphorotriamide (GMPP), pyridine (PY), as well as compounds that inhibit radical reactions: 2,2-di-(n oksifenil)-propane (Suite); 2,6-ditretbutyl-4-methyl-phenol (BHT), n-NITROPHENOL.About the effectiveness of the used complex catalytic systems when receiving EDC chlorination of ethylene judged on the following parameters:
content (wt.) the target product and the products of the side chlorination in coming out of the reactor EDC raw without pre-treatment;
validity of the catalyst;
the flow of catalyst to edit the system drying chlorine, supplied from a cylinder, the chlorination reactor and system for capturing gases.To prevent possible accumulation and the catalytic effect of ferric chloride, is easily generated in the presence of chlorine steel reactor experiments were used reactors chlorination of lead and glass.Chlorination of ethylene was carried out at the boiling point of EDC (84,5oC) and temperatures of 20, 45oC an EDC. For chlorination of ethylene at the boiling temperature of EDC was used bubbling reactor type, made of lead (N=800 mm, d=70 mm), equipped with a condenser and a jacket for heating. The reactor was loaded fresh EDC containing not less than 99.9% and a complex catalytic system of 0.1 to 2.0 wt. Then EDC was heated to 60oC and submitted chlorine 12,0 l/h and ethylene 12.5 l/h due to the heat of the reaction temperature in the reactor rises to the boiling point of EDC. Pair EDC from the reactor is cooled and condensed in the condenser, from which part of the EDC is returned to the reactor, and a portion is withdrawn continuously at this rate, to ensure a constant level of the liquid phase in the reactor. The content of EDC and impurities in selected product and the reaction mass was determined by GC-analysis of the TB reactor through the bubblers were filed ethylene and chlorine, with a cost of 7.5 and 7.0 l/h, respectively. Received EDC raw continuously withdrawn in the receiver. After the EDC distillation bottoms distillation residue containing the catalytic system is returned to the synthesis reactor EDC to maintain the initial concentration of the catalyst. As a result of experiments revealed that the catalytic system is stable and does not lose activity upon recycling (more than 10 times).Further examples of chlorination of ethylene in the presence of the proposed catalytic systems.Example 1. Chlorination of ethylene in the presence of catalytic systems (iron dichloride, gmpt, Suite 2 Mac. at a temperature of 84oC.Charged to the reactor 1000 g EDC (99,9%), 4.5 g of iron dichloride, 5,85 g gmpt and 10.0 g Suite. Chlorine and ethylene are served with a cost of 12.0 and 12.5 l/h, respectively. The duration of the opt 450 hours During this time received 23770 g of the product with the content of EDC 99,9% (trichloroethane 0,10%). At the end of the experiment the content of EDC in selected product made of 99.85 wt. (trichloroethane - 0,15%).Similarly conduct the process of chlorination of ethylene in the examples 2 to 23. Conditions and results of experiments are shown in table. 1.Example 24. In a glass reactor (V=1000 ml) equipped with a stirrer, bubblers chlorine and ethylene, load 800 g of EDC (99,9%) and 3.8 g whom is responsible. The temperature in the reactor support 45oC. EDC Formed through the side outlet in the reactor is poured into the receiver. Received the product in a quantity of 500 ml is subjected to rectification, with the cube of the evaporating device containing the catalyst returned to the chlorination reactor. During the experience (400 hours) accumulated 12370 g of the product with the content of EDC at 99.95% (trichloroethane 0,05%).Similarly, lead the process of chlorination of ethylene in examples 25 to 35. Conditions and results of experiments are shown in table. 2. Method for producing 1,2-dichloroethane by chlorination of ethylene with chlorine in the liquid 1,2-dichloroethane at a temperature of 20oC to the boiling temperature of the reaction mass in the presence of a metal complex catalyst in an amount of 0.1 to 2.0 wt. and inhibitor of radical reactions, characterized in that the catalyst used complex halide of a metal selected from the group FeCl2, FeCl3, SnCl4, SbCl5with the nitrogen-containing compound selected from the group hexamethylphosphorotriamide, pyridine, and as an inhibitor of radical reactions using 2,2-di-(n oksifenil)-propane, 2,6-di-tertbutyl-4-METHYLPHENOL, n-NITROPHENOL.
FIELD: industrial organic synthesis.
SUBSTANCE: invention is dealing with production of chlorohydrocarbons exhibiting plasticizing properties in polymer compositions in production of synthetic building materials, varnishes and paints, artificial films and leathers, in rubber industry, and as fire-retardant additives in polymers. Process comprises chlorination of waste obtained in production of C14-C32 fraction by ethylene-α-olefin oligomerization. Chlorination is accomplished in two steps: addition chlorination at 35-55°C followed by substitution chlorination at 40-105°C. Chlorohydrocarbons thus obtained can, in particular, be used as secondary plasticizer in polyvinylchloride compositions.
EFFECT: reduced expenses due to using production waste.
4 tbl, 30 ex
FIELD: petrochemical and industrial organic synthesis.
SUBSTANCE: process comprises separating gaseous pyrolysis products to recover ethylene-containing fraction with 54-65% ethylene content and C3-C5-hydrocarbon fraction. Ethylene-containing fraction is subjected to liquid-phase catalytic chlorination. Gas phase of chlorination product is purified via adsorption and fed into furnace as fuel. C3-C5-Hydrocarbon fraction is subjected to exhaustive hydrogenation, hydrogenation product is combined with fresh raw material at weight ratio (0.05ч1):1 and sent to pyrolysis plant.
EFFECT: achieved integration of process, increased reliability thereof, and reduced expenses.
1 dwg, 1 tbl, 15 ex
FIELD: organic chemistry.
SUBSTANCE: 1,2-dichloroethane is obtained by liquid phase ethylene chlorination with discharging of reaction heat due to operation medium boiling. In claimed process nitrogen is added to chlorine and ethylene reagents. Ratio of chlorine volume consumption to nitrogen volume consumption is maintained as 1:1. Reaction is carried out at temperature lower than 1,2-dichloroethane boiling point, and discharging of reaction heat is carried out by evaporative cooling of operation medium in nitrogen.
EFFECT: process of increased selectivity; decreased yield of by-products.
1 tbl, 5 dwg
FIELD: chemical industry; designs of the bubble-type reactors for production of 1.2-dichloroethane.
SUBSTANCE: the invention is pertaining to the design of the bubble-type reactors for production of 1.2-dichloroethane by the method of the liquid-phase chlorination of ethylene with the reaction heat removal at boiling of the working medium. As the contact device the reactor uses two layers of the metallic nozzle. The liquid 1.2-dichloroethane is fed from above to the nozzle, into the space between the layers of the nozzle feed the gaseous chlorine with nitrogen, and under the lower layer of the nozzle feed the gaseous ethylene with nitrogen, that allows to reduce the diameter of the reactor in 1.5-2 times due to the increased effectiveness of stirring and formation of the developed contact surface of the phases. At that the heat of the reaction is removed by evaporation of 1.2-dichloroethane in nitrogen. At that the temperature of the liquid is maintained below the boiling temperature. The technical result of the invention is the increased selectivity of the process, reduction of the outlet of the by-products (the highest ethane chlorides) and the decreased overall dimensions of the reactor.
EFFECT: the invention ensures the increased selectivity of the process, reduction of the outlet of the by-products (the highest ethane chlorides) and the decreased overall dimensions of the reactor.
1 ex, 4 dwg
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for synthesis of 1,2-dichloroethane by method of liquid-phase chlorination of ethylene. The process is carried out by direct feeding gaseous reagents chlorine and ethylene in liquid reaction medium of reactor. Before feeding into reactor chlorine and ethylene are heated preliminary in heat-exchangers to temperature equal to that of liquid in reactor. Method provides enhancing selectivity of process and reducing formation of by-side substances representing higher chlorine-derivatives of ethane.
EFFECT: improved method of synthesis.
4 dwg, 1 ex
FIELD: chemical technology.
SUBSTANCE: invention relates to a method for synthesis of 1,2-dichloroethane by method of liquid-phase chlorination of ethylene. Method involves maintaining the optimal ratio of heat eliminated based on evaporation and heat eliminated based on cooling a liquid medium in a heat exchanger in the process. One-sixth part of heat formed in reactor is eliminated based on evaporation of synthesized compound in boiling and 5/6 part of formed heat is eliminated based on circulation of liquid working medium in external heat exchanger. The temperature gradient in the reaction zone is maintained equal 52°C. Invention provides enhancing selectivity of process and reducing amount of by-side products of reaction (higher chlorine-derivate of ethane).
EFFECT: improved method of synthesis.
3 dwg, 1 ex