摘要
采用固定床模式,研究了钛硅分子筛催化环己酮制环己酮肟液相氨肟化反应.结果表明,该工艺模式具有可行性与普适性.优化的反应条件为:温度333K,体系氨浓度>2%,酮/H2O2摩尔比=5,H2O2空速0.083h-1.此时环己酮转化率、环己酮肟选择性、H2O2转化率及其有效利用率分别达18.7%,99.5%,94.7%和98.7%.进一步研究了H2O2在该过程中的反应行为,发现固定床工艺模式能有效提高H2O2的有效利用率,其主要原因是该模式有利于羟胺的生成及其进一步与酮反应生成肟.适当的空速与氨和酮的浓度是实现H2O2高效利用的关键因素.
Liquid-phase ammoximation of cyclohexanone to the corresponding oxime was conducted in a fixed-bed reactor over titanium silicalite(TS-1),which was proved to be a feasible and universal process.The primary rules of ammoximation were explored in the fixed-bed reactor system.The initial results indicated that the utilization of H 2 O 2 was enhanced obviously through this mode,which is attributed to successful hydroxylamine generation and smooth contact with ketones.Further investigations of H 2 O 2 reaction behavior showed that the proper weight hourly space velocity of H 2 O 2 and the concentrations of ammonia and ketone both play a key role in highly efficient utilization of H 2 O 2 .The cyclohexanone and H 2 O 2 conversion,cyclohexanone-oxime selectivity,and H 2 O 2 efficiency reached 18.7%,94.7%,99.5%,and 98.7%,respectively,under the optimum reaction conditions of temperature of 333 K,ammonia concentration higher than 2%,cyclohexanone/H 2 O 2 molar ratio of 5,and WHSV(H 2 O 2) of 0.083 h-1 with 85% t-BuOH as solvent.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2013年第3期604-611,共8页
基金
国家自然科学基金(20973064)
国家科技支撑计划(2012BAE05B02)
上海市科委基础研究重点项目(12JC14030600)
上海市重点学科建设项目基金(B409)~~
关键词
环己酮
肟化
钛硅分子筛
固定床
过氧化氢
cyclohexanone
ammoximation
titanium silicalite
fixed bed
hydrogen peroxide
