混合碳4裂解制乙烯和丙烯的研究

催化裂化过程中生产的混合碳4（简称为C4）中含有50％左右的丁烯，是很好的制乙烯和丙烯，尤其是丙烯的原料。在固定床反应装置上对C4裂解制乙烯和丙烯过程中LXH—Ⅰ型催化剂的性能进行了评价。结果表明，该催化剂具有较高的乙烯、丙烯选择性，反应中还可生成一部分含5个碳原子以上的烃。丁烯的转化率、乙烯和丙烯的收率在反应初期有所下降，随后分别稳定在58％，13％和40％左右。实验还表明，丁烯是先二聚然后裂解生成乙烯和丙烯的。

Cracking of mixed C4 hydrocarbons to ethylene and propylene

Approximately 50% of mixed C_4 hydrocarbons produced during FCC process is butene,which is a good feedstock to produce ethylene and propylene,especially propylene.The performances of LXH-I catalyst were investigated in a fixed-bed apparatus during the cracking reaction of the mixed C_4 to ethylene and propylene.The results show that butene can be converted to ethylene and propylene with high selectivity.Simultaneously,a certain amount of C~+_5 is also formed.The conversion of butane,and the yields of ethylene and propylene drop with time during the early stage of reaction,then maintain constant basically.The stable conversion of butene,and the yields of ethylene and propylene are around 58%,13% and 40% respectively.It is also shown that the cracking reactions of butene to ethylene and propylene may proceed via the mechanism of first dimerization then cracking.