采用气相转移法(Q)、原位合成法(Y)和涂覆法(z),制备出了3个系列的不同SAPO-34含量的SAPO-34/堇青石整体式催化剂。采用XRD和N2-吸脱附等分析测试技术表征了催化剂的结构,在固定床反应器上评价了整体式催化剂的甲醇制烯烃反应性能。结果表明:3个系列的SAPO.34/堇青石整体式催化剂堇青石表面SAPO-34分子筛的基本骨架没有发生大的改变,气相转移法制备的催化剂具有相对较大的比表面积,原位合成法制备的催化剂具有相对稍大的孔径。在催化剂的SAPO-34含量相近的情况下,气相转移法制备的催化剂具有最好的催化性能;以(Q)19.7%SAPO-34/堇青石整体式催化剂为例,在反应温度380~420℃、空速520—810mL/(g·h)的条件下有利于低碳烯烃的生成。在400℃和670mL/(g·h)的反应条件下,低碳烯烃的选择性最高,乙烯和丙烯的选择性分别可达到40.91%和32.80%,乙烯和丙烯的总选择性能达到73.71%。
Three series of silicon aluminium phosphate SAPO-34/cordierite monolithic catalysts have been prepared on a pretreated cordierite support by vapor transfer, in situ synthesis and direct coating methods. The samples were characterized by XRD and N2adsorption-desorption measurements. The catalytic performance of the SAPO-34/cor- dierite monolithic catalysts for methanol to olefin conversion was evaluated in a fixed-bed micro-reactor. The results showed that the structure of the SAPO-34 molecular sieve was retained in all of the SAPO-34/cordierite monolithic catalysts. The BET surface area of the SAPO-34/cordierite monolithic catalysts prepared by the vapor transfer meth- od were higher than those of materials prepared by the other methods. The pore diameter of the SAPO-34/cordierite monolithic catalysts prepared by the situ synthesis method were larger than those of the other materials. For catalysts with similar SAPO-34 contents, the catalytic activities of SAPO-34/cordierite monolithic catalysts prepared by the vapor transfer method were the best. The optimum conditions for production of olefins involved temperatures in the range 380-420 ℃ and feed space velocities in the range 520 -810 mL/(g·h). A 19.7% SAPO-34/cordierite monolithic catalyst prepared by the vapor transfer method had the best catalytic activity for methanol to olefin con- version. The seleetivities to ethene and propylene of this catalyst were 40.9% and 32.8% , respectively, and the total selectivity of the olefins reached 73.7% at a temperature of 400 ℃ and space feed velocity of 670 mL/(g·h).