What are the uses of methyl chloride?
Publication Time:
2022-11-08 11:26
Source:
Methyl chloride is mainly used in the production of methylchlorosilane, with 50% to 90% of the world's methyl chloride used in organosilicon production. It is also used in the production of methyl cellulose, tetramethyl lead, herbicides, butyl rubber, quaternary ammonium compounds, etc. It can also be used as a refrigerant, blowing agent, and solvent for rubber, resins, and organic compounds. In medicine, it is used as a local anesthetic. Examples of its applications are as follows:
1) Preparation of methane chlorides by thermal chlorination of methyl chloride. After the raw materials methyl chloride, diluent gas, and chlorine gas are mixed, they enter the reactor and react at a high temperature of around 380-440℃. The high-temperature gas produced is then rapidly cooled, condensed, and separated to separate hydrogen chloride and crude chlorinated liquid. The hydrogen chloride is recycled to produce methyl chloride, and the collected crude chlorinated liquid is sent to the distillation section for purification. After using this invention's preparation method, the process is greatly shortened compared to the traditional process, production capacity is increased, unit energy efficiency is high, and the utilization rate of raw material chlorine is increased, resulting in lower investment and consumption for the entire device. This process does not use the water and alkali washing of the traditional process, and no three wastes are produced.
2) Preparation of 2,3,3,3-tetrafluoropropene. Using difluoromonochloromethane (R22) and methyl chloride as raw materials, thermal cracking reaction is carried out in the presence of N2 gas at a high temperature of 600~1000℃ to obtain 2,3,3,3-tetrafluoropropene; wherein the volume ratio of difluoromonochloromethane to methyl chloride is 1~3∶1, and the reaction residence time is 0.01~0.2s. The reaction raw materials used in this invention are readily available, overcoming the shortcomings of high raw material costs in the existing technology and greatly reducing the production cost, and the process reaction process is simple. The obtained 2,3,3,3-tetrafluoropropene has the advantages of zero ODP and low GWP and can be used as a substitute for automotive air conditioning refrigerants.
3) Preparation of trimethylaluminum, including the following steps: Under inert gas protection, magnesium aluminum alloy powder and hydrocarbon solvent are added to the reactor, and stirring is started for 5-15 minutes; then, the inducer 1,2-diiodoethane is added to the stirred reactor; methyl chloride is gradually added under vigorous stirring, and the reaction temperature is controlled at 120-160℃ during the addition of methyl chloride; stirring is continued for 2-3 hours at a reaction temperature of 120-160℃; when the material temperature is controlled at 110-160℃, the trimethylaluminum receiving bottle is pre-cooled to -20℃, and trimethylaluminum is distilled under vacuum of -0.05Mpa—--0.095Mpa; the molar ratio of inducer, methyl chloride, and aluminum in magnesium aluminum alloy powder is 1-2:100:20-25; the weight ratio of methyl chloride to solvent is 1:1.5~2.5. This invention has low cost, high reaction efficiency, high safety, and is not easy to introduce impurities.