Catalytic Synthesis of Tri-n-butyl Citrate and Acetyl Tri-n-butyl Citrate
|Keywords||Plasticizer Tributyl citrate Acetyl tributyl citrate Macroporous strong acid cation exchange resin Catalytic Tubular fixed bed reactor|
This paper reports the citric acid, n-butanol as raw materials in the presence of a catalyst synthesis of tributyl citrate (TBC), and to synthesize the TBC, acetic anhydride, in the presence of a catalyst synthesis of acetyl tributyl citrate (ATBC) study results. Catalytic Synthesis on ATBC tried tube fixed bed reactor for synthesis operation, and achieved satisfactory results. In the literature, based on the first use of sodium hydrogen sulfate as catalyst TBC, the reaction material ratio, reaction time and the amount of catalyst and other process conditions were investigated to optimize the process conditions, TBC yield reached 97.6 %, higher than the literature value of 95.0%; while also using macroporous strong acid cation exchange resin, 4A zeolite as a catalyst to the reaction system was studied, and achieved good experimental results, the two catalysts in the optimization process conditions TBC, yields were 83.0% and 76.5%. Using the above synthesized TBC, the catalyst sodium bisulfate, macroporous strong acid cation exchange resin, under the effect of using acetic anhydride as acetylating agent for the synthesis of ATBC study material and the reaction ratio, reaction temperature, time and the amount of catalyst used and other process conditions were optimized, the optimal process conditions, the two catalyst ATBC 99.5% yield and 99.8%, higher than the literature values. And raw materials citrate close to 100% conversion rate, to avoid separation of the TBC and ATBC difficult issues, post-treatment process is simple. 4A also tried two kinds of HZSM-5 zeolite and the reaction system was studied, the results show that they are not suitable for this system. Tubular fixed bed reactor using synthetic ATBC, the macroporous strong acid cation exchange resin as a catalyst and a fixed bed of filler material, was found after wetting the catalyst, the catalytic activity was improved in the low temperature can be to achieve a higher yield. Preliminary investigation of the molar ratio of the reactants, the temperature of the water heating cycle, feed rate, catalyst loading height on yield of ATBC. In the right conditions, TBC conversion rate close to 100%, and almost no other byproducts. In this purification process proposed TBC and the product obtained by the gas chromatography analysis of the ATBC content of more than 99%, in line Morflex Co. Standards.