硅铝比对SAPO-34催化剂在甲醇制烯烃反应中催化性能的影响  

Performances of SAPO-34 Catalysts with Different Ratios of Si to Al in Methanol-to-Olefins

作　　者：唐君琴[1] 叶丽萍[1] 应卫勇[1] 房鼎业[1] 

机构地区：[1]华东理工大学大型工业反应器工程教育部工程研究中心化学工程联合国家重点实验室,上海200237

出　　处：《石油化工》2010年第1期22-27,共6页Petrochemical Technology

基　　金：国家科技支撑计划项目(2006BAE02B02)

摘　　要：以四乙基氢氧化铵-三乙胺为模板剂,采用水热法合成了SAPO-34催化剂;研究了不同硅铝比(n(SiO2)∶n(Al2O3))合成的催化剂催化甲醇制烯烃反应的性能;并用XRD,BET,SEM,NH3-TPD等手段对催化剂进行了表征。实验结果表明,当n(SiO2)∶n(Al2O3)=0.30时,SAPO-34的结晶度最大,比表面积为490m2/g,晶粒粒径最大(0.6～1.5μm);随n(SiO2)∶n(Al2O3)的增大,SAPO-34的结晶度减小,比表面积增大,晶粒粒径减小。在反应温度425℃、甲醇的WHSV=1h-1时,以甲醇为原料,对不同n(SiO2)∶n(Al2O3)合成的催化剂的催化性能进行评价结果显示,当n(SiO2)∶n(Al2O3)=0.30时,甲醇转化率达到100.0%,低碳烯烃(乙烯+丙烯)的总选择性最高(达到86.87%),催化活性时间最长(546min);随n(SiO2)∶n(Al2O3)的增大,催化剂对低碳烯烃(乙烯+丙烯)的总选择性降低,催化活性时间缩短。SAPO-34 catalysts, used in methanol to olefins （MTO）, with different n （SiO2） ： n（A12O3） （0. 15 -0.80 ） were prepared hydrothermally with tetraethyl ammonium hydroxide and triethylamine as templates. The SAPO-34 catalysts were characterized by means of XRD, SEM, BET and NH3-TPD. The results indicated that when n （ SiO2 ） ： n （ Al2O3 ） was 0.30, crystallinity of the prepared catalyst was maximal, and its specific surface area and crystallite size range were 490 m^2/g and 0.6 - 1.5 μm respectively. With increase of n （ SiO2 ） ： n （ Al2 O3 ）, crystallinity and crystallite size of the catalysts decreased, but its specific surface area increased. Under optimal MTO conditions： temperature 425 ℃, methanol WHSV 1 h^-1 and n（ SiO2 ） ： n（A12O3 ） of SAPO-34 catalyst, conversion of methanol, the total selectivity to ethylene and propylene, and lifetime of the catalyst could reached 100.0%, 86. 87% and 546 min, respectively. With increase of n （ SiO2 ） ： n （ Al2O3 ） , the total selectivity to ethylene and propylene and the lifetime of the catalysts all reduced.

关 键 词：SAPO-34催化剂 甲醇制烯烃 乙烯 丙烯 硅铝比 四乙基氢氧化铵 三乙胺 

分 类 号：TQ426.94[化学工程]