甲醇制烯烃催化剂SAPO-34分子筛的制备和喷雾成型

摘要

SAPO-34分子筛用于催化甲醇转化制烯烃，乙烯和丙烯选择性高，是很好的甲醇制烯烃催化剂。由于SAPO-34分子筛失活速率快，甲醇制烯烃反应器通常是连续循环再生的流化床反应器，SAPO-34分子筛必须喷雾成型并达到一定抗磨强度后才能使用。在50 L反应釜合成了SAPO-34分子筛，并在中试喷雾装置上，以SAPO-34为活性组分喷雾成型甲醇制烯烃催化剂。结果表明，喷雾成型甲醇制烯烃催化剂的抗磨损指数为1.58%·h-1，抗磨性能达到工业应用要求，与两种工业甲醇制烯烃催化剂对比，喷雾成型甲醇制烯烃催化剂寿命最长，达260 min，乙烯、丙烯选择性以及乙烯+丙烯总选择性在对应的各个反应时间点均最高，260 min分别达到49.09%、35.05%和84.98%。%SAPO-34 molecular sieve is the good catalyst for methanol to olefins( MTO)process with high selectivity to ethylene and propylene. Because of the high deactivation rate of SAPO-34 caused by coke deposition on the catalyst,the MTO process usually adopts a continuous recycling fluidized bed to make continuous regeneration of the catalysts. Therefore,SAPO-34 molecular sieve catalysts should be formed by spray drying process to reach high attrition resistance. SAPO-34 molecular sieve was synthesized in a 50 L reactor. Using SAPO-34 molecular sieve as the active component,the attrition-resistant MTO catalyst was prepared by the spray drying process in a pilot scale unit. The results indicated that the as-propared MTO catalyst with the attrition index of 1. 58%·h-1 met the requirement for the catalyst attrition-resistance of commercial application. Compared with two commercial MTO catalysts,the self-made MTO catalyst possessed the longest service life which reached 260 min,and its selectivity to ethylene,propylene and ethylene+propylene was the highest at each time point,which were 49. 09%,35. 05% and 84. 98%, respectively,after reaction for 260 min.