催化裂化过程中丙烯和丁烯选择性的影响因素

采用ACE评价装置详细研究了重油催化裂化过程中丙烯、丁烯选择性的影响因素。研究表明，随着反应温度的升高，丙烯、丁烯选择性存在极大值，且丁烯选择性的极值温度要低于丙烯；随反应剂油比的增大，丙烯、丁烯选择性均呈下降趋势，但丁烯选择性的下降幅度明显大于丙烯；随择形分子筛含量的增加，丙烯选择性有所提高，但丁烯选择性下降，择形分子筛的改性方式同样影响丙烯和丁烯选择性；随Y型分子筛晶胞常数增大，丙烯、丁烯选择性均下降，且丁烯选择性下降幅度大于丙烯

IMPACT FACTORS ON SELECTIVITIES OF PROPYLENE AND BUTENE IN FCC PROCESS

ACE (Advanced Catalyst Evaluation) was employed to investigate the factors impacting the selectivities of propylene and butene in the process of catalytic cracking of heavy oil. The results showed that with the increase of temperature, there were maximum values for the selectivities of propylene and butene. But the corresponding reaction temperature for maximum butene selectivity was lower than that of propylene; with the increase of cat-to-oil ratio, selectivities of both propylene and butene decreased. However, the selectivity for butene dropped more than that of propylene; the increase of ZSM-5 zeolite was in favor of propylene, while selectivity of butene decreased. Moreover, modification ways of ZSM-5 had an impact on the selectivities of the both light olefins; with the increase of the molecular sieve cell constant of Y zeolite, the selectivities of the two olefins were decreased and the selectivity of butene decreased more than that of propylene.