The sulfur-transfer catalyst is widely used to remove the sulfur oxides (SOx ) from the flue gas in the fluid catalytic cracking (FCC) units. This paper reports the influence of the pore structure of the Ce/MgAl hydrotalcite-derived mixed oxides on its SO x pick-up capacity. The Ce/MgAl hydrotalcites precursors were synthesized by the separate nucleation and aging steps (SNAS), and then were calcined in air at 800℃ to prepare the Ce/MgAl mixed oxides. And in our preparations, the pore structures of the Ce/MgAl mixed oxides were controlled by modifying the aging time of the hydrotalcites precursors. It is found that with the aging time of 4 to 6 h produced the largest pore volume (the largest total pore volume and the least pore less than 10 nm) and resulted in the largest SOx pick-up capacity.
采用常规水热法合成SAPO-11和ZSM-22分子筛,制备分别含有分子筛的催化剂,借助XRD、SEM和NH3-TPD表征2种催化剂的结构和酸性,并以加氢预精制溶剂脱蜡油为原料,采用固定床反应器研究Pt/SAPO-11和Pt/ZSM-22催化剂的加氢异构反应性能.结果表明:催化剂的反应活性和选择性主要取决于催化剂的酸量和酸强度,相对而言,由于SAPO-11分子筛催化剂弱酸含量较高,具有更佳的异构化选择性.利用1 H NMR和13 C NMR核磁共振研究加氢异构反应前后基础油的化学结构变化,Pt/SAPO-11催化剂有较高的加氢异构选择性.
