C_(4)烯烃转化制丙烯工艺及催化剂研究

Research on the process of C_(4)olefins to propylene and catalysts

目的开发C_(4)烯烃催化裂解制丙烯工艺和催化剂制备工艺技术,完成小试和工业侧线试验。方法采用固定床评价装置考查了催化剂配方、改性及工业条件对催化剂活性、选择性、稳定性能的影响。结果以ZSM-5分子筛为活性组分的催化剂在C_(4)烯烃转化制丙烯反应中具有较好的活性、选择性、稳定性和再生性,磷的引入未改变催化剂的晶型结构,但降低了催化剂酸性位点数量,并调节了催化剂的n(B酸)/n(L酸),随着磷负载量增加到5%(w),分子筛中磷与铝的相互作用逐渐增强,磷可以和骨架铝和非骨架铝相互作用。结论C_(4)烯烃的转化率达到80%以上,丙烯的选择性达到35%~45%,催化剂的单程寿命达到一个月以上,且经再生后,再生恢复率达95%。

Objective To develop the process of catalytic cracking of C_(4)olefins to propylene and the catalyst preparation technology,the pilot test and industrial side line test are completed.Methods The fixed-bed evaluation apparatus was used to investigate the impact of catalyst formulation,modification,and industrial conditions on catalyst activity,selectivity,and stability.Results The catalyst with ZSM-5 zeolite as the active component had good activity,selectivity,stability and regeneration performance in the conversion of C_(4)olefins to propylene.The introduction of phosphorus did not change the crystal structure of the catalyst,but it reduced the number of acidic sites on the catalyst,and adjusted the molar ratio of B acid and L acid of ZSM-5 zeolite.With the increase of phosphorus loading to 5 wt%,the interaction between phosphorus and aluminum in molecular sieves was gradually strengthened,and phosphorus could interact with framework aluminum and non-framework aluminum.Conclusions The conversion rate of C_(4)olefins is more than 80%,the selectivity of propylene is 35%-45%,the once-through life of catalyst is more than one month,and the regeneration recovery rate is 95%.