苯甲醛清洁生产工艺研究

采用硫酸锰与碳酸铵反应制得的碳酸锰为原料 ,在 3种温度条件下连续焙烧转化成Mn2 O3 ,将Mn2 O3 、硫酸和甲苯进行固、油、水非均相氧化反应 ,制备苯甲醛 .反应结束后 3相自然分层 ,油相经简单蒸馏分出苯甲醛产品 ,没反应的甲苯循环使用 ;水相中还原生成的硫酸锰 ,循环与碳酸铵反应 ,制备碳酸锰 ;固相剩余的Mn2 O3 用于循环氧化反应 .对整个工艺流程优化 ,5次循环后的苯甲醛转化率仍保持在 75 %左右

Green Technology Optimum for Benzaldehyde Production

The green chemical technology of benzaldehyde production was developed. Manganese sulfate reacted with ammonium carbonate to yield manganese carbonate and ammoniun sulfate. Manganese carbonate was baked under three different temperatures for changing to manganese sesquioxide, which could react with toluene in the terms of 7.0mol/L surphric acid in a three phase reactor to produce benzaldehyde. After reaction, the three phases(solid,oil,aqueous) were separated automatically. The benzaldehyde was separated from oil by distillation while unreacted toluene could be reused. The manganese sulfate in aqueous could react with ammonium carbonate to yield manganese carbonate again. The residual manganese sesquioxide recycle used. These recycle technolygys formed a closed recycle system, and the optimum operation conditions have been obtained. After five times recycle operation, the benzaldehyde exchanging rate also kept about 75%.