Coke evolution on a Y-zeolite based catalyst and its influence on the active site and catalytic activity during catalytic pyrolysis of polyethylene for fuel oil were investigated. Results show that the coke evolution includes both quantity accumulation and structural condensation. The coke amounts increase from 0.8% at TOS = 1 h to 2.4% and 6.3% at TOS = 2 h and 4 h respectively, and the external coke deposits faster than the internal coke. Structural condensation is evidenced by DTG, H/C, ¹³C NMR, FTIR and UV-Vis results. The average coke model changes from a tricyclic aromatic to a hexacyclic alkyl aromatic as TOS increases from 1 h to 4 h. Coke evolution causes catalyst deactivation, resulting in the decrease of oil yields but increase of wax yields and heavy oil concentration. The strong acid sites and micropores favor the coke deposition, and fast external deposition leads to slow decrease of acidities with coke yields.

研究了Y沸石基催化剂上焦炭的生成及其对聚乙烯催化裂解制燃料油过程中活性位和催化活性的影响。结果表明，焦炭的演化既包括量的积累，又包括结构的凝结。焦炭量从TOS = 1 h时的0.8％分别增加到TOS = 2 h和4 h时的2.4％和6.3％，外部焦炭的沉积速度快于内部焦炭。DTG，H / C，¹³表明存在结构性凝结C NMR，FTIR和UV-Vis结果。随着TOS从1小时增加到4小时，平均焦炭模型从三环芳烃变为六环烷基芳烃。焦炭的释放导致催化剂失活，导致油收率降低，但蜡收率和重油浓度增加。强酸位和微孔有利于焦炭沉积，快速的外部沉积导致酸度随焦炭收率的下降缓慢。