The Contrast Research with Two Kinds of Catalysts for Catalytic Synthesis of Mixed Dimethyl Esters

With by-product of mixed dibasic acid( DBA) and methanol as raw materials,using composite solid acid and PW12/ Si O2 as catalyst for the synthesis of mixed dimethyl esters( DBE) respectively,it was found that two kinds of catalyst under the conditions had the similar synthesis conditions. The optimum conditions were as follows: the both mole ratio of methanol and acid( DBA) was 3. 5,the dosage of the catalyst were mixed dibasic acid( DBA) quality 2%,reaction time was 4 h,water carrying agent amount was 50 m L /100 g DBA. Under the above conditions,the yield of DBE two catalysts were close to 85%,the total mass fraction product ester were all above 98. 6%,and the two kinds of catalyst used repeatedly for 5 times,the yield of DBE was greater than 70%. Considering the advantages and disadvantages,under the same experimental conditions and the yield of DBE and similar conditions,the use of solid acid catalyst heating catalytic esterification of mixed dimethyl esters had higher economic benefits and environmental benefits and better application prospect.