分子氧催化氧化环己酮反应精馏合成ε-己内酯OA

Powdered Ce-Sn catalyst was shaped into structured packing via extrusion molding.The catalyst was characterized by XRD,XRF,N2 adsorption-desorption,SEM,and other techniques.The as-prepared catalyst was used as packing,and its activity in the catalytic oxidation of cyclohexanone to ε-caprolactone with molecular oxygen was evaluated in a fixed-bed reactor and a catalytic reactive distillation unit separately.The experimental results show that the packed Ce-Sn shaped catalyst prepared under the conditions of 25%(w)pseudo-boehmite and 3%(w)activated carbon exhibits high mechanical strength,excellent pore structure,and good catalytic activity.Under the optimal conditions of reaction temperature of 65℃,gas flow rate of 55 L/h,aldehyde/ketone molar ratio of 2,solvent mass ratio of 10∶1,and reflux ratio of 1∶3 in the catalytic reactive distillation process,the cyclohexanone conversion reaches 40.8%,the single-pass yield of ε-caprolactone is 35%,and the selectivity to ε-caprolactone is 85.5%.These values are all higher than those of the fixed-bed catalytic process,and the amount of 1,2-dichloroethane is reduced by 15%(w),which leads to a 48.2%decrease in cost.