Application and Market of Dimethyl Carbonate in Pesticides
In the field of pesticides, dimethyl carbonate is mainly used to produce methyl isocyanate, which in turn produces carbamate pesticides. The main pesticides are carbaryl, propoxur, carbofuran, and methomyl. The global market consumption of dimethyl carbonate in pesticides is about 10,000 t/a. With the continuous introduction of new pesticide varieties, some products will replace the application of carbamate insecticides in agricultural production to some extent. Therefore, in the next few years, the production and market consumption of carbamate pesticides There will be basically a small increase. At present, the market consumption of dimethyl carbonate in China's pesticide industry is still relatively small, about 5,000t/a. With the pace of adjustment of the structure of pesticide industry, five kinds of highly toxic organophosphorus pesticides such as methamidophos in 20071 From January 1st, it is completely banned from circulation in China. The market share of alternative pesticides such as carbofuran and indoxacarb will be further expanded. Some major pesticide producers in China have already had considerable expansion plans. Therefore, the market demand for dimethyl carbonate in these pesticide varieties has considerable potential to be tapped.
Industrial production methods of dimethyl carbonate mainly include phosgene method, transesterification method and methanol oxidative carbonyl method. Due to the toxic nature of phosgene, the phosgene method has been phased out. The transesterification process has been very mature after years of industrial operation. Methanol oxidative carbonylation has no side reactions, and it is a key process route developed by countries all over the world. The product development of dimethyl carbonate in China began in the early 1980s. The early production methods were all phosgenation methods, and the production scale of the devices was generally 300~500t/a. After the 1990s, a large number of development studies were carried out on the production process of non-phosgene dimethyl carbonate. Through nearly 30 years of research and development, China's dimethyl carbonate production process has been greatly improved. At present, the phosgene production equipment has been discontinued, and the liquid phase oxidative carbonyl process has been initially applied. It has formed an industrial production unit of 4000t/a (Hubei Xingfa Group Co., Ltd.); the urea process technology has also passed the national appraisal; The transesterification process has been developed on a large scale, and the sum of production capacity accounts for more than 90% of the total capacity. It has become the mainstream process for the production of dimethyl carbonate in China.