化学液相沉积法改性ZSM-5沸石上的甲苯择形歧化反应:Ⅱ水蒸气处理与反应条件的影响  

Shape selective disproportionation of toluene over HZSM-5 zeolite modified by chemical liquid deposition:Ⅱ Effect of hydrothermal treatment and reaction conditions

作　　者：何云鹏[1] 任晓乾[1] 梁金花[1] 王军[1] 李凯[1] 

机构地区：[1]南京工业大学化学化工学院,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2006年第6期15-18,共4页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省高校自然科学基金(04KJ13530044)

摘　　要：采用水蒸气对化学液相沉积硅改性HZSM 5催化剂进行了处理,考察了250~500℃时水热处理温度对催化剂在甲苯择形歧化反应中的催化活性和对二甲苯选择性的影响。实验结果表明,300~350℃时的水热处理效果较好,甲苯转化率和对二甲苯选择性分别达到23.5%和96.5%。在高对位选择性的催化剂上,详细考察了反应温度、反应压力、氢气与甲苯进料比和甲苯进料速率对甲苯转化率、对二甲苯选择性和收率的影响。实验结果表明,高压、较低温度、低液相空速有利于提高对二甲苯的收率,在反应温度420℃、压力2.5 MPa、甲苯的质量空速为1.5 h-1、氢烃摩尔比为2~3的条件下,甲苯转化率为25.8%,选择性为94.1%,对二甲苯收率为10.5%。Hydrothermal treatment on the conversion of toluene and selectivity of p-xylene(PX) in toluene disproportionation over the HZSM-5 catalyst modified with silica by chemical liquid deposition were investigated.The catalyst was treated with steam at the temperature of 250～500 ℃ under atmospheric pressure.After the steam treatment at 300～350 ℃ for 2 hours,the conversion of toluene and selectivity of PX reached 23.5% and 96.5%,respectively.Reaction conditions,such as reaction temperature,pressure,WHSV and H_2/toluene(molar ratio),were investigated in toluene disproportionation.The results indicated that high pressure,relatively low reaction temperature and low WHSV increased the yield of PX.The activity,selectivity and yield of PX reached 25.8%,94.1% and 10.5%,respectively,under the reaction conditions of 420 ℃,2.5 MPa,(1.5h^(-1)),2～3 of molar ratio of H_2/toluene.

关 键 词：HZSM5 水热处理 甲苯歧化 择形催化 

分 类 号：TQ460.32[化学工程—制药化工]