Hydrochlorination of ethylene

Ethyl Chloride. Most ethyl chloride [75-00-3] is produced by the hydrochlorination of ethylene (qv) using anhydrous HCl. Historically, the primary use of ethyl chloride was for the manufacture of tetraethyllead (TEL), a primary component of antiknock mixes in gasolines. Use has declined as a... 

Three industrial processes have been used for the production of ethyl chloride hydrochlorination of ethylene, reaction of hydrochloric acid with ethanol, and chlorination of ethane. Hydrochlorination of ethylene is used to manufacture most of the ethyl chloride produced in the United States. Because of its prohibitive cost, the ethanol route to ethyl chloride has not been used commercially in the United States since about 1972. Thermal chlorination of ethane has the disadvantage of producing undesired by-products, and has not been used commercially since about 1975. 

Hydrochlorination of Ethylene. The exothermic vapor-phase reaction between ethylene [74-85-1] and hydrogen chloride [7647-01-0] can be carried out at 130—250°C under a variety of catalytic conditions. Yields are reported to be greater than 90% of theoretical (14). 

By-product HCl may be used for the hydrochlorination of ethylene to produce more ethyl chloride. Hydrochlorination of ethylene, however, is the main route for the production of ethyl chloride ... 

Chloroethane is produced by the hydrochlorination of ethylene. It is used in the manufacture of tetraethyllead, as an industrial ethylating agent, as a blowing agent in the production of polystyrene foam and as a local anaesthetic. Occupational exposure occurs during the production of tetraethyllead, and industrial emissions have led to detectable levels of chloroethane in ambient air (lARC, 1991). 

Ethyl Chloride. Hydrochlorination of ethylene with HC1 is carried out in either the vapor or the liquid phase, in the presence of a catalyst.182-184 Ethyl chloride or 1,2-dichloroethane containing less than 1% A1C13 is the reaction medium in the liquid-phase process operating under mild conditions (30-90°C, 3-5 atm). In new plants supported AlClj or ZnCl2 is used in the vapor phase. Equimolar amounts of the dry reagents are reacted in a fluidized- or fixed-bed reactor at elevated temperature and pressure (250-400°C, 5-15 atm). Both processes provide ethyl chloride with high (98-99%) selectivity. 

Ethylchloride. At present the main industrial technique to produce ethylchloride is the hydrochlorination of ethylene. 

Finally, ethylchloride can be obtained by a combined technique from a mixture of ethane and ethylene. The process is based on combined subsequent reactions of substitutuve chlorination of ethane and hydrochlorination of ethylene with hydrogen chloride obtained from the first reaction ... 

Ethyl Chloride. Most of the ethyl chloride is made by the exothermic hydrochlorination of ethylene, in either the liquid or the vapor phase Ain... 

Figure 2.35 Dependence of the cooling zone length and heat emission coefficient a on the hydrodynamic mode of the tubular device operation using water (O) (heat exchange) and ethyl chloride ( ) (heat exchange in the liquid-phase hydrochlorination of ethylene) at constant process output (10.3 m /h).

The mechanisms of fast processes, during polymer synthesis, are the same for all low molecular weight (MW) compounds, including the chlorination and hydrochlorination of ethylene, sulfuric acid alkylation of paraffins by olefins, neutralisation of acid and alkali media, and so on. Thus, the formation of different macroscopic types, during fast chemical reactions, is a common phenomenon which can be observed in almost all fast chemical processes, including the interaction of low MW compounds. 

Ethyl chloride is commercially produced by the liquid-phase hydrochlorination of ethylene in large-scale reactors (2 m ), in the presence of AICI3. Reactors are equipped with mechanical mixing devices and an external heat removal system the temperature in the mixing zone may locally increase up to 100 °C or more. 

There is no information on the specific reaction rate of the hydrochlorination of ethylene to chloroethane in the relevant literature or reference books. However, this reaction relates to rapid processes according to the technical rules, = 5 s at more than 93 mass% of the ethylene change ratio, which results in fe > 190 1/mohs (238°C). Therefore, turbulent reactors are the most appropriate devices for this... 

Significant quantities of ethyl chloride are also produced as a by-product of the catalytic hydrochlorination over a copper chloride catalyst, of ethylene and hydrogen chloride to produce 1,2-dichloroethane, which is used as feedstock in the manufacture of vinyl choride (see Vinyl polymers). This ethyl chloride can be recovered for sale or it can be concentrated and catalyticaHy cracked back to ethylene and hydrogen chloride (25). As the market for ethyl chloride declines, recovery as an intermediate by-product of vinyl chloride manufacture may become a predominant method of manufacture of ethyl chloride. 

Direct chlorination of vinyl chloride generates 1,1,2-tnchloroethane [79-00-5] from which vinylidene chloride required for vinylidene polymers is produced. Hydrochlorination of vinylidene chloride produces 1,1,1-trichloroethane [71-55-6], which is a commercially important solvent. Trichloroethylene and perchloroethylene are manufactured by chlorination, hydrochlorination, or oxychlorination reactions involving ethylene. Aromatic solvents or pesticides such as monochlorobenzene, dichlorobenzene, and hexachlorobenzene are produced by reaction of chlorine with benzene. Monochlorobenzene is an intermediate in the manufacture of phenol, insecticide DDT, aniline, and dyes (see Chlorocarbons a>td Chlorohydrocarbons.)... 

Vinyl chloride is produced in the following industrial reactions (1) the thermal cracking of 1,2-dichlor-oethane, which is produced by the chlorination and/ or oxychlorination of ethylene and (2) the hydrochlorination of acetylene. The vast majority of vinyl chloride is used for the production of polyvinyl chloride (PVC) and the manufacture of copolymers with monomers such as vinyl acetate or vinylidene chloride. A much smaller proportion of vinyl chloride is used in the production of chlorinated solvents - primarily trichloroethanes. 

Air oxidation of a variety of aliphatic and alkyl aromatic compounda air oxidation of p-nitrotoluene sulfuric acid substitution chlorination of a variety of organic compounds reaction between isobutylene and acetic acid oxidation of ethylene to acetaldehyde (Wacker processes) hydrochlorination of olehns absorption of phosphine in an aqueous soluhon of formaldehyde and hydrochloric acid acehc acid from the carbonylation of methanol oxidation of tri-alkyl phosphine dimerization of olefins. 

As in steam cracking, a large number of by-products is produced. Some of them result from the consecutive reactions of the chlorination of vinyl chloride and of its derivatives obtained by dehydrochlorination (tri-, tetra-, pentachloroethane, perchloro-ethane, di-, trichloroethylene. perchloroethyleneX and the others from the hydrochlorination of vinyl chloride il.l-dichloroethane), while others result from decomposition reactions (acetylene, cokei or conversion of impurities initially present (hydrocarbons such as ethylene, butadiene and benzene, chlorinated derivatives such as chloroprene, methyl and ethyl Chlorides, chloroform, carbon tetrachloride, eta, and hydrogen) ... 

Figure 9-3. Technological scheme of production of the vinyl chloride monomer (1) plasma-chemical pyrolysis (2) cleaning from higher unsaturated hydrocarbons (3) hydrochlorination of acetylene (4) chlorination of ethylene (5) thermal pyrolysis of dichloroethane.

Values of Lcooi (by the exan le of ethylene hydrochlorination) and R for various number of tubes providing at given productivity of shell-and-tube reactor the temperature about 273 K in reaction zone at two values of Tc (238K and 258K) are presented in Table 4.2. 

Monomer. VCM is produced industrially by two main reactions (1) hydrochlorination of acetylene and (2) thermal cracking of 1,2-dichloroethane produced by direct chlorination or oxychlorination of ethylene in the balanced process. Presently, more than 90% of the VCM prodnced is based on this route. 

At one time, hydrochlorination of acetylene was the major source of vinyl chloride. As the cost of production of acetylene increased, however, manufacturers of vinyl chloride sought other routes to this material. The starting material chosen was ethylene, which can be converted to vinyl chloride in two steps treating ethylene with chlorine gives 1,2-dichloroethane, which, when heated in the presence of charcoal or other catalyst, loses a molecule of HCl to form vinyl chloride. 

There are several commercial gas-solid catalysed reactions in which heat transfer plays a significant, if not dominant, role in limiting the reactor productivity, lowering the process selectivity and reducing the life of the catalyst. Among these include the oxidation of ethylene, benzene, C hydrocarbons and methanol, the ammoxidation of propylene, methanol synthesis (Lurgi), the hydrochlorination of methanol and steam reforming of natural gas and naphtha. 

Halogenation and dehalogenation are catalyzed by substances that exist in more than one valence state and are able to donate and accept halogens freely. Silver and copper hahdes are used for gas-phase reactions, and ferric chloride commonly for hquid phase. Hydrochlorination (the absoration of HCl) is promoted by BiCb or SbCl3 and hydrofluorination by sodium fluoride or chromia catalysts that form fluorides under reaction conditions. Mercuric chloride promotes addition of HCl to acetylene to make vinyl chloride. Oxychlori-nation in the Stauffer process for vinyl chloride from ethylene is catalyzed by CuCL with some KCl to retard its vaporization. 

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