|
|Section2= |Section7= |Section8= }} Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene ("perc" or "PERC"), and many other names, is a chlorocarbon with the formula Cl2C=CCl2. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid." It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about one million metric tons in 1985.〔M. Rossberg et al. "Chlorinated Hydrocarbons" in ''Ullmann’s Encyclopedia of Industrial Chemistry'', 2006, Wiley-VCH, Weinheim. 〕 ==Production== Michael Faraday first synthesized tetrachloroethylene in 1821 by thermal decomposition of hexachloroethane. :C2Cl6 → C2Cl4 + Cl2 Most tetrachloroethylene is produced by high temperature chlorinolysis of light hydrocarbons. The method is related to Faraday's discovery since hexachloroethane is generated and thermally decomposes.〔 Side products include carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene. Several other methods have been developed. When 1,2-dichloroethane is heated to 400 °C with chlorine, tetrachloroethylene is produced by the chemical reaction: :ClCH2CH2Cl + 3 Cl2 → Cl2C=CCl2 + 4 HCl This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon. Trichloroethylene is a major byproduct, which is separated by distillation. According to an United States Environmental Protection Agency (EPA) report of 1976, the quantity of tetrachloroethylene produced in the United States in the 1973 totaled 320,000 metric tons (706 million lb).〔"Assessment of Hazardous Waste Practices: Organic Chemicals, Pesticides and Explosives Industries" prebpublication issue for EPA Libraries and Solid Waste Management Agencies under contract # 68-01-2919, USEPA 1976〕 By 1993, the volume produced in the United States had dropped to 123,000 metric tons (271 million lb).〔 citing C&EN, 1994, Facts and Figures for the Chemical Industry, ''Chemical and Engineering News'', July 4, 1994.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tetrachloroethylene」の詳細全文を読む スポンサード リンク
|