摘要
考察了丙烯在 ZSM-5和 ZSM-5型镓硅分子筛(记为 Ga-ZSM-5)上的反应。温度较低时两者均使丙烯发生齐聚-裂解反应,自175℃起均开始产生芳烃,且芳烃产率均随温度升高而增加。反应结果表明,ZSM-5使丙烯齐聚物通过与小分子烯烃的氢转移反应生成芳烃,而在 Ga-ZSM-5上则主要是丙烯齐聚物直接脱氢环化实现芳构化。在 Ga-ZSM-5上芳烃产率比在 ZSM-5上高得多,对于 Ga-ZSM-5,Ga 含量增加,芳构化能力增强。
Aromatization of propylene,at room temperatures to 550℃,on ZSM-5 and ZSM-5
type gallosilicates(Ga-ZSM-5)has been investigated.Propylene oligomerization,
t(?)gether with cracking of the oligomers,is the main reaction on both catalysts below 300℃,thus forming a variety of olifines.At elevated temperatures,however,
aromatization becomes important.A rule is set up to calculate the fraction of aro-
matics formed through oligomer dehydrocyclization or through H-transfer reac-
tion.The results show that aromatization is realized predominantly through de-
hydrocyclization on Ga-ZSM-5 but mainly through H-transfer between C_(6+)~= and
C_2~=—C_5~= on ZSM-5.However,the fraction through dehydrocyclization on ZSM-5
increases with increasing reaction temperature.The selectivity and yield of aro-
matics are much higher on Ga-ZSM-5 than on ZSM-5,showing that Ga-ZSM-5
possesses excellent aromatization capabilities.
出处
《石油化工》
CAS
CSCD
北大核心
1990年第9期587-592,共6页
Petrochemical Technology
