摘要
考察了晶化时间、模板剂用量、投料硅铝比、水硅比等条件对纳米Beta沸石的影响。结果表明:采用四乙基溴化铵(TEA)为模板剂,在晶化温度160℃,晶化时间45 h,TEA与SiO2物质的量之比0.25,SiO2与Al2O3物质的量之比25,水硅物质的量之比16的条件下,合成的Beta沸石的晶粒尺寸为20 nm左右,且具有较大的比表面积。放大合成的Beta沸石也具有纳米粒子特征,引入絮凝剂可以提高纳米沸石的回收率。采用纳米Beta沸石合成的BTA-02催化剂对二异丙苯烷基转移反应具有良好的催化性能,在苯和二异丙苯质量比1.5,二异丙苯的质量空速1.6 h-1,反应温度160℃,反应压力为1.0～1.3 MPa的条件下,二异丙苯转化率为50%～60%,产品中正丙苯(NPB)与异丙苯(IPB)的质量比为5×10-4～6×10-4。
The effects of crystallization time, template dosage, molar ratio of SiO2 to A1203 and molar ratio of H20 to Si on the synthesis of nano-Beta zeolite were investigated. The results showed that, the nano-Beta zeolite had large specific surface area and its crystal size was 20 nm, which was synthesized with tetraethylammonium bromide （TEA） as template under the conditions of crystallization temperature 160 ℃, crystallization time 45 h, molar ratio of TEA to SiO2 0.25, molar ratio of SiO2 to A1203 25, molar ratio of H20 to Si 16. The Beta zeolite synthesized in large-scale also had nano-particle characteristics, and the introduction of the flocculant could achieve a high nano-zeolite yield. BTA-02 catalyst prepared from nano-Beta zeolite exhibited good catalytic performance for diisopropylbenzene （DIPB） transalkylation. The conversion of DIPB reached 50%-60% and mass ratio of n-propane to iso-propane was 5x10^-4 -6x10^-4 under the reaction conditions of mass ratio of benzene to DIPB 1.5, weight hourly space velocity of DIPB 1.6 h^-1, reaction temperature 160℃ and reaction pressure 1.0-1.3 MPa. The high activity of nano-Beta zeolite catalyst was attributed to its small crystal size.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2012年第4期312-318,共7页
Chemical Reaction Engineering and Technology
