改性TS-1催化固定床丙烯环氧化反应

 采用四丙基氢氧化铵（TPAOH）稀溶液对TS-1进行改性，考察了不同改性条件对成型后催化剂在丙烯环氧化反应中的催化性能的影响，同时考察了反应条件即反应温度、丙烯空速、双氧水浓度、氨水浓度，以及催化剂床层长/径比、催化剂粒度等对改性TS-1催化丙烯环氧化反应H2O2转化率和环氧丙烷选择性的影响。结果表明，经TPAOH改性的TS-1催化剂在在丙烯环氧化反应中的催化性能优异，在反应温度45℃、反应压力3.0 MPa、丙烯空速0.6 h-1、总空速3.5 h-1的条件下，采用摩尔比 为3的丙酮和甲醇为溶剂、H2O2浓度1.1 mol/L、氨水浓度0.4 mmol/L、催化剂颗粒度1 mm × 1 mm和床层长/径比为11，丙烯环氧化反应的H2O2转化率和环氧丙烷选择性均可以达到且稳定在95%以上。1500h运转结果表明，催化剂具有高的催化活性、环氧丙烷选择性和稳定性。

PROPYLENE EPOXIDATION OVER MODIFIED TS-1 CATALYSTS IN FIXED-BED REACTOR

TS-1 samples were modified with dilute tetrapropyl ammonium hydroxide (TPAOH) aqueous solution. The effects of modification conditions on the catalytic properties of extruded TS-1 samples in propylene epoxidation were investigated. The reaction conditions, such as reaction temperature, space velocity of propylene, concentration of H2O2, concentration of ammonia, length/diameter radio (L/D) of the catalyst bed, particle size of the extruded catalyst, were optimized. The results showed that the suitable reaction conditions were as follows: reaction temperature of 45℃, reaction pressure of 3.0 MPa, total space velocity of 3.5 h-1, propylene space velocity of 0.6 h-1, by using the mixture of acetone and methanol with a mole ratio of 3 as solvent, H2O2 concentration of 1.1 mol/L, ammonia concentration of 0.4 mmol/L, , particle size of the catalyst 1 mm×1 mm and L/D of the catalyst bed of 11, under which the conversion of H2O2 and the selectivity of propylene oxide reached above 95% and kept stable. A long tern of 1500 h reaction showed that the extruded TS-1 catalyst modified with TPAOH exhibited high activity, selectivity of propylene oxide and stability in epoxidation of propylene.