Clean Production Technology Of Dipheny Carbonate

T his paper studies the clean production technology of diphenyl carbonate, which is synthesized by phosgene and phenol in the presence of S type composite catalyzer. Phosgene production and instant use technology, catalyst recycling technology, phenolic water recycling and disposal technology, byproduct hydrochloric acid absorption technology, energy comprehensive utilization technique are included in this clean production technology. Finally, by using basic chemical unit operation technology, like reduced pressure distillation, the purity of biphenyl carbonate products is above 99.8%.The cores of clean production are “energy conservation, consumption reduction, decreasing pollution and increasing efficiency”. Chongqing Changfeng Chemical Industry Co.Ltd. is a chemical enterprise which uses gas as raw materials. The production process of arylamine uses “hydrogen”, and the production process of hosgene derivatives consumes “carbon”. Therefore, the gas can be made full use of.Phosgene production and instant use technology reduces the amount of toxic phosgene from more than 20 tons to about two or three hundred kilograms, which embodies the requirements of decreasing toxicant in clean production and controls the level of harm from the source when accidents happen. Phosgene catalytic synthesis technology of diphenyl carbonate is developed by traditional sodium phenolate synthesis methods. Catalytic synthesis technology and catalyst recycling technology improve the percent conversion and reaction selectivity of phenol and the amount of phenol wastewater reduces by more than 99%. By-product hydrochloric acid absorption techniques changes the waste HCL into byproducts. These processes reduce pollution, turning “waste” into wealth and maximize outputs.The technology of integrating energy includes using chemical reaction heat and cascade usage of energy. On the one hand, it reduces separation of by-product phenol and diphenyl carbonate in the production of makrolon, making byproducts affect directly on raw materials to synthesize diphenyl carbonate. On the other hand, it lowers energy consumption greatly and achieve the goal of energy saving.Combined use of basic unit technologies mentioned above employ these simple unit technologies to the utmost. Thus, it has lower energy consumption and little wastes in the production process, and the consumption of raw materials is close to the theoretical value. Finally, the unity of economic, social and environmental benefits is realized.