槽外式在线超声间接电合成苯甲醛/对甲基苯甲醛的工艺改进

Improvement of Process for Out-cell Indirect Electrosynthesis Benzaldehyde/p-Methylbenzaldehyde with Online Ultrasound

针对传统槽外式间接电合成方法反应体积过大、效率比较低的缺陷,实验采用在线超声非均相电解和高浓度氧化液逐滴加入法,对原有槽外式间接电合成苯甲醛类化合物的工艺进行了改进。改进后的工艺不仅使Mn(Ⅱ)的转化率达到96.73%,电流效率为85.01%,而且制得的较高浓度Mn(Ⅲ)氧化液无需稀释可直接使用,有效缩小了反应液的体积,比原有工艺至少降低了200%以上,且有机原料用量也减少了50%.这大大节省了反应所用的原料和设备空间,也在一定程度上提高了反应效率和产品收率,从而解决了由此引发的反应液体积过大所带来的反应效率低下的问题。本工艺制备苯甲醛和对甲基苯甲醛的收率分别为77.14%和92.52%.

In view of the excessive reaction volume and low current efficiency appearing in the conventional out-cell indirect electrosynthesis process,on line ultrasonic heterogeneous electrolysis and drop-by-drop addition of high-concentration oxidation solution were adopted to optimize the synthesis process for the production of benzaldehyde and its derivatives. The improved process was easy to operate,the conversion rate of Mn （Ⅱ） was over 96.73%,the current efficiency was 85.01%,the obtained high concentration Mn （Ⅲ） could be directly used without dilution,which effectively reduced volume of reaction solution at least 200% with respect to the traditional process and halved the amount of organic ingredients. The process greatly saved the amount of raw materials and equipment space, and solved the problems of low reaction efficiency caused by the excessive reaction solution volume, the yield of benzaldehyde and p-methyl benzaldehyde reached 77.14% and 92.52% respectively in the improved process.