丙烯齐聚过程中非齐聚物选择性的研究(下)

Study on Selectivity of Non - oligomers in Process for Propylene Oligomerization (Ⅱ)

丙烯齐聚过程中,烯烃异构化、烯烃加成和聚合物裂解三种反应并存,裂解生成的低碳烯烃再加成产生的非齐聚物是低价值副产物。影响非齐聚物选择性的主要因素是反应温度T和接触时间6(=S_v^(-1))。随着T的上升和9的延长,裂解倾向增加,轻非齐聚物选择性S_(C7+c8)和重非齐聚物选择性S_(C10+C11)及其总和S_(?)变大。固体磷酸催化剂(SPAC)的异构化作用使齐聚生成的端烯烃迅速转化为加成活性低的内烯烃,进一步加成的倾向减缓,从而使SPAC具有齐聚物选择性高的特点。

In propylene oligomerization, three reactions occur simultaneously: isomerization of olefins. olefin addition and cracking of polymer. Low carbon olefins procreated by cracking of polymer re - add to produce non -oligomers that are byproducts of low worth. Primary factors which influence selectivity of non-oligomer are reactive temperature T and contact time θ ( = Se-1 ). As ascending of temperature and prolong of the contact time, tendencies of polymer cracking increase, thereby the selectivity of non -oligomer get larger, include light non-oligomer S0.7-0.8. heavy non - oligomer S0.10+0.11 and their summation Snon- ,Solid phosphoric acid catalysts possess high activity of isomerization that rapidly translate terminal olefin into nonterminal olefin. Adding activity of nonterminal olefin is much lower than that of terminal olefin, accordingly the tendency of more addition of the oligomer be diminished. Depending on the high isomerization activity, SPAC have a characteristic of high nonene and dodecene selectivity