Fe_2O_3/HZSM-5催化转化乙醇制备低碳烯烃

采用浸渍法制备了Fe2O3/HZSM-5分子筛催化剂,并用于乙醇脱水与低聚制备丙烯为主的低碳烯烃反应体系.在400～500℃范围内考察了HZSM-5的硅/铝比、氧化铁负载量、反应温度、催化剂氢气还原预处理对产物中烯烃收率的影响.结果表明,HZSM-5硅/铝比为140时,丙烯、丁烯收率最高;氧化铁负载能有效提高烯烃收率,当负载量为2.9%时丙烯收率最高,接近25%;反应初期升高温度可促进丙烯生成,但催化剂寿命缩短;氢气还原预处理能进一步促进乙烯、丙烯生成.

Catalytic Conversion of Ethanol to Light Olefins over Fe_2O_3/HZSM-5 Catalyst

The catalytic conversion of ethanol to light olefins over Fe_2O_3/HZSM-5 catalyst prepared with impregnation method was investigated. The selectivity of olefins was tested against the ratio of silica to alumina and amount of iron oxide in catalyst, reaction temperature and pretreatment method for the catalyst in the temperature range of 400～500℃. It was demonstrated that propylene and butylenes were in good yield at the ratio of silica to alumina of 140, while iron impregnation onto HZSM-5 obviously increased the yields of these light olefms. The highest propylene yield of about 25% was realized when iron oxide loading was 2.9%. Elevating reaction temperature increased the selectivity to propylene at the initial reaction stage but shortened the activity lifetime of catalyst. Catalyst reduction in advance with HE further promoted the production of propylene and ethylene.