甲烷氧化偶联Na_2WO_4-Mn/SiO_2催化剂用于乙烷脱氢

研究了高效甲烷氧化偶联制乙烯Na2WO4-Mn/SiO2催化剂对C2H6热裂解脱氢及C2H6与CO2、O2氧化脱氢反应的催化性能。实验结果表明,Na2WO4-Mn/SiO2催化剂在800℃以上可有效促进C2H6的高温热裂解脱氢反应,同时在CO2存在时C2H6与CO2发生明显的氧化脱氢反应;O2存在时,C2H6与O2发生氧化脱氢反应,在660℃时,C2H6转化率可达63.3%,乙烯选择性可达68.2%。考察了反应条件对C2H6与O2氧化脱氢反应的影响,实验结果表明,C2H6与O2的体积比大时,可有效提高目的产物乙烯的选择性,提高空速可抑制CO2的生成,稀释气(水蒸气)的引入仅能部分抑制CO2的生成,对CO选择性和C2H6转化率的影响不大。

Catalytic Performance of Na2WO4-Mn/SiO2 Catalyst in Ethane Dehydrogenation

Na_2WO_4-Mn/SiO_2 is known as an excellent catalyst for oxidative coupling of methane.Its catalytic performance in thermal cracking dehydrogenation and oxidative dehydrogenation of ethane were investigated.The catalyst can accelerate thermal cracking dehydrogenation of ethane when temperature is higher than 800 ℃,and ethane can be oxidized simultaneously into ethylene in presence of CO_2.In existence of oxygen at 660 ℃,ethane conversion and ethylene selectivity can reach 63.3% and 68.2%, respectively.High volume ratio of ethane to oxygen is strongly favorable to ethylene selectivity.Increase of gas hourly space velocity can inhibit generation of CO_2.Introducing of diluent(steam)can partially inhibit generation of CO_2,and its effect on selectivity of CO and conversion of ethane are unobvious.