固体酸催化合成C_(4～6)混合二元酸二甲酯

Catalytic synthesis of C_(4-6) mixed dimethyl esters with composite solid acid catalyst

以C_(4～6)混合二元酸、甲醇为原料,固体酸为催化剂,合成C_(4～6)混合二元酸二甲酯。进行了不同种类催化剂筛选、反应工艺条件优化及催化剂寿命的实验研究,确定了适宜的酯化反应条件:以干氢树脂酸为催化剂,反应时间4.5h、酸醇物质的量比1:5、催化剂加入量10%、反应温度74～82℃。在此条件下,混合二元酸转化率达87.8%。干氢树脂酸催化剂连续使用4次时,混合二元酸转化率仍达80%以上。

C4 -6 mixed dimethyl esters （DME） are prepared using C4-6 mixed dibasic acids （DBA） and methanol as raw materials and composite solid acid as catalyst. The effects are tested in different reaction condition of catalyst, reaction time, mole ratio of methanol to DBA, catalyst amount and catalyst recycled times. The optimum conditions are as follows：reaction temper- ature 74-82 ℃, mole ratio of methanol to DBA 5/1, dosage of composite solid acid mass ratio to DBA 10 % and reaction time 4.5 h. Under these conditions, the yield of DME is 87.8 %. When composite solid acid is recycled for 4 times, the yield of DME is still above 80%, which shows good stability and reusability of composite solid acid.