Optimization Of Synthetic Process Of Tri-n-butyl Citrate And Acetyl Tri-n-butyl Citrate

Acetyl Tri-n-Butyl Citrate?ATBC?is one kind of outward appearance colorless transparent liquid.In opposite to the traditional phthalic acid ester plasticizer for it is be internationally recognized as an non-toxic plasticizer at present,its green environmental protection merit in professions and so on be widely applied in food packing,medicine health,having the broad prospects for development.Take the citric acid as raw material.The general synthetic method of ATBC is through the esterification and the acylation responded from citrie acid.The key lies in selecting the appropriate catalyst to guarantee the product's purity and luster,and cut down the production cost as far as possible.This article studies'innovation lies in taking the NaHSO₄/4A molecular sieve as the catalysts of esterification reaction and acylation reaction.The final product is not only with high productivity and purity,moreover solved the formerly question that decolorized difficulty.The catalysts easy to get and separate,stability is well,and the redundant use is simple.Having determined the catalysts of each step response,studies and optimizes the synthesis craft route of ATBC were carried out.And the pilot process parameters were determined through the verification experiment.Finally obtained the optimum esterification conditions as follows:molar ration of citric acid to butyl alcohol is 1:4.5,the mass of catalyst is 2.5%?based on NaHSO₄,NaHSO₄:4A molecular sieve=1:2?,the reaction time is 150 min,the reaction temperature is 145?C.The optimum acylation conditions as follows:The feeding ration?TBC and acid anhydride mole of ratio?1:1.3,the catalyst amount used 1.5%?based on NaHSO₄,NaHSO₄:4A molecular sieve=1:2?,the reaction time is 50 min,the reaction temperature is 50?C.Recycling acid anhydride through reduced pressure distillation,again menses and soda lye wash,the final product was obtained after two reduced pressure distillation,Based on the technological conditions through the above experiment,we made up a pilot design,the yearly produced 15 tons ATBC experimental lines'design was carried on.The main parameters were calculated for each production section and the preliminary design of the main equipments.This experimental line production method is the intermittent operation,with lower construction cost,the simplify operation,and hopefully to realize the industrialization.