丙酮液相氨肟化连续流反应

Continuous Flow Process for Ammoximation of Acetone in Liquid Phase

摘要:

在液相条件下，以丙酮、氨水和双氧水为原料，钛硅分子筛（TS-1）为催化剂，叔丁醇为溶剂，在具有特殊微结构的连续流微通道反应器中一步氧化合成丙酮肟。实验考察了双氧水浓度、氨水用量、双氧水用量、溶剂用量、助催化剂用量以及温度对氨肟化的影响，结果表明：AFR微通道反应器中，反应器出口压力5 bar，温度100 ℃，催化剂浓度8 g/mol（mol为丙酮的单位），氨水/双氧水/叔丁醇/丙酮摩尔比=3:1.1:6:1，双氧水浓度70 wt.%，氨水浓度25 wt.%，助催化剂浓度3 mg/mol（mol为丙酮的单位），停留时间72 s，获得丙酮转化率为80%，丙酮肟选择性为97%，丙酮肟的收率为77%。AFR微通道反应系统持液量小、停留时间短、强传质传热等特点，强化了反应物料和催化体系之间的协同效应，提高了氨肟化反应速率，解决了双氧水分解带来的氨肟化反应本质安全问题，实现了丙酮氨肟化的绿色安全高效合成。

Abstract:

Acetoxime was synthesized by one-step oxidation in a continuous flow micro-channel reactor with special micro-structure, using acetone, ammonia and hydrogen peroxide as raw materials, titanium silicalite（TS-1） over catalyst and tertbutanol as solvent. The effects of concentration of hydrogen peroxide, ammonia, hydrogen peroxide, solvent, co-catalyst and temperature on ammoximation were investigated. The results showed that under conditions of outlet pressure of AFR micro-channel reactor system was 5 bar, temperature at 100 ℃, and catalyst concentration was 8 g/mol(acetone unit), molar ratio of ammonia/H2O2/tertbutanol/ acetone=3:1.1:6:1, concentration of H2O2 and ammonia were 70 and 25 wt% respectively, concentration of co-catalyst was 3 mg/mol(acetone unit), residence time was 72 s, conversion of acetone reached 80%, selectivity of acetoxime reached 97%, and yield of acetoxime reached 77%. AFR micro-channel reaction system had significant advantages, including small liquid holding capacity, short residence time, strong mass transfer and heat transfer, which strengthened coordination effect between reaction material and catalytic system, reaction rate of ammoximation was also increased considerably, essence safety of acetone ammoximation caused by decomposition of hydrogen peroxide was solved effectively, and green, safe and efficient of acetone ammoximation was realized.