反应精馏与吸附耦合合成醋酸甲酯新工艺

New process for methyl acetate based on reaction rectification and adsorption dehydration

以731阳离子交换树脂固体酸为催化剂、醋酸和甲醇为原料,采用反应精馏与分子筛吸附脱水耦合的方式合成醋酸甲酯。考察了原料配比、催化剂用量、回流比和反应时间等因素对酯化反应的影响。通过实验得到了最佳酯化反应工艺条件:731阳离子交换树脂质量分数4%,n(醋酸)∶n(甲醇)=3∶1,回流比R=0.8,反应时间t=7 h,在该条件下甲醇的转化率达到99.4%,精馏制得的醋酸甲酯质量分数能达到99.5%。催化剂重复使用6次后,甲醇的转化率仍可达到98.9%,得到的醋酸甲酯质量分数仍高于99%。色谱显示产物几乎没有副产物,反应选择性很高。

Methyl acetate is synthesized based on reaction rectification and adsorption dehydration using 731 dry hydrogen type of cation exchange resin as catalyst, the glacial acetic acid and methanol as raw materials. The effects of catalyst content, molar ratio of methanol to acetic acid, reflux ratio and reaction time are studied. The optimal operation parameters are shown as follows：4% of 731 dry hydrogen type of cation exchange resin, 3：1 of n（ acetic acid）： n（methanol） ,0. 8 of reflux ratio R and 7 hours of reaction time. Under this conditions the content of methyl acetate in products is 99.5% , and the conversion rate of the ester can reach 99.4%. After the catalyst have been reused 6 times, under the optimized reactions conditions,the content of methyl acetate in products can be more than 99% and the yield of the ester still can reach 98.32%.