Methanol, hydrochlorination

LiquidPha.se. The methyl chloride process with the widest use in the United States is the Hquid-phase methanol hydrochlorination process. SHicone producers use methyl chloride in its manufacture and produce an aqueous hydrochloric acid stream as a by-product. This by-product HCl is converted back to methyl chloride by hydrochlorination. In fact, it is possible to produce methyl chloride directiy from the chioromethylsilane hydrolysis step in the siHcone process (18,19) (see Silicon compounds, silicones). 

Gas Phase. The gas-phase methanol hydrochlorination process is used more in Europe and Japan than in the United States, though there is a considerable body of Hterature available. The process is typicaHy carried out as foHows vaporized methanol and hydrogen chloride, mixed in equimolar proportions, are preheated to 180—200°C. Reaction occurs on passage through a converter packed with 1.68—2.38 mm (8—12 mesh) alumina gel at ca 350°C. The product gas is cooled, water-scmbbed, and Hquefied. Conversions of over 95% of the methanol are commonly obtained. Garnma-alurnina has been used as a catalyst at 295—340°C to obtain 97.8% yields of methyl chloride (25). Other catalysts may be used, eg, cuprous or zinc chloride on active alumina, carbon, sHica, or pumice (26—30) sHica—aluminas (31,32) zeoHtes (33) attapulgus clay (34) or carbon (35,36). Space velocities of up to 300 h , with volumes of gas at STP per hour per volume catalyst space, are employed. 

Production and sales data for methyl chloride, as reported by the U.S. International Trade Commission for the years 1945 to 1989, are given in Table 3. Production grew tremendously in the 1960s and again in the late 1980s. Methanol hydrochlorination was used to produce about 64% of the methyl chloride in 1969 and about 98% by 1974. The principal U.S. producers and their capacities are shown in Table 4 (54). These capacities do not include the 100 + million kg per year used by The Dow Chemical Company, Occidental, and Vulcan to captively produce other chloromethanes. 

Gas-phase methanol hydrochlorination process, 16 322-323 Gas-phase mirage-effect spectroscopy,... 

Methyl chloride currently is produced by two methods by the reaction of hydrogen chloride and methanol and by the chlorination of methane. Methanol hydrochlorination has become increasingly important, whereas methane chlorination has declined as the route to produce only methyl chloride. The hydrochlorination process has the advantage that it utilizes, instead of generating, hydrogen chloride, a product whose disposal has become increasingly difficult. The reaction of methanol with excess hydrogen chloride is carried out in the gas phase at temperatures... 

Hydrochlorination of Alkynes When Thomas and coworkers treated different alkynes in aqueous methanol with HAuC14 and observed the corresponding ketones as major products (Equation 8.28), with less than 5% of methyl vinyl ethers and vinyl chlorides, they were unaware of the fascinating treasure that was in front of them. Some of the most important types of products for gold catalysis were reported in the aforementioned study, but unfortunately at that time this process was believed to be a gold(III) oxidation process, despite the fact that the reaction achieved almost six turnovers. 

Dichloromethane was first prepared by Regnault in 1840 by the chlorination of methyl chloride in sunlight. It became an industrial chemical of importance during the Second World War. Two commercial processes are currently used for the production of dichloromethane—hydrochlorination of methanol and direct chlorination of methane (Rossberg etal., 1986 Holbrook, 1993). 

Methyl chloride (< 50ppm water, only impurity) 6000 longtons Hydrochlorination of methanol. 

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. 

Terpenic-type intermediates of use in formation of the side-chain in tocopherols have been derived from myrcene (ref. 118). Thus, a mixture of E- and Z-isomers from its hydrochlorination which resulted in a dichloroderivative containing primary and tertiary halide groups was reacted with trimethylhydroquinone in dioxane/dichloromethane containing zinc chloride, zinc and hydrogen chloride to afford an 89% yield of a chloro intermediate. Dehydrochlorination in methanol with sodium hydroxide afforded a mixture of pentenyl compounds which was isomerised with toluenesulphonic acid in refluxing benzene to 6-hydroxy-2,5,7,8-tetramethyl-2-(4-methyl-3-pentenyl)chroman. The elaboration of the side-chain to produce the tocopherol structure was not described and the synthesis is not stereospecific... 

MAJOR USES Chloroalkylating agent in the preparation of anionic exchange resins lachrimatory agent intermediate for chloromethylated compound used in the process of hydrochlorination of methanol and formaldehyde used in the production of chloromethylated compounds. 

Via methyl chloride chlorination. Methyl chloride is made by hydrochlorination of methanol or direct chlorination of methane... 

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. 

Methyl chloride chlorination, hydrochlorination methane, methanol chloromethanes, chloroethanes, chloroethylenes... 

The following discussion examines the role of the two materials under consideration. Section 2 reviews fundamental issues connected with the role of fluorinated chromia as an active catalyst for a variety of reactions Section 3 considers physicochemical attributes of the acid site distribution associated with rj-alumina catalysts as applied to a single reaction, namely the synthesis of methyl chloride via the hydrochlorination of methanol. 

An alternative feedstock of growing significance is methanol, which may be transported much more easily than methane. In this case, the first stage is hydrochlorination which yields methyl chloride, which is then further chlorinated. 

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