Long-term stability test of Mo/HZSM-5-N catalysts(HZSM-5-N stands for nano-sized HZSM-5) in methane dehydroaromatization(MDA)reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 100...Long-term stability test of Mo/HZSM-5-N catalysts(HZSM-5-N stands for nano-sized HZSM-5) in methane dehydroaromatization(MDA)reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 1000 h.During this test,methane conversion ranges from 13% to 16%,and mean yield to aromatics(i.e.benzene and naphthalene) exceeds 10%.N2-physisorption,XRD,NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition,and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke,thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition.The effect of zeolite particle size on the catalytic activity was also explored,and the results showed that the nano-sized zeolite with low diffusion resistance performed better.It is recognized that the size effect was enhanced by reaction time,and it became more remarkable in a long-term MDA reaction even at a low space velocity.展开更多
为提升瓦斯抽采利用率、促进煤矿安全生产,采用介质阻挡放电(DBD)试验系统对CH4-O2-N2-H2O反应体系进行低温等离子体转化研究,分析水蒸气与CH4物质的量比、O2/N2物质的量比、放电电压、放电频率,以及气体总流量对CH4转化率及主要产物产...为提升瓦斯抽采利用率、促进煤矿安全生产,采用介质阻挡放电(DBD)试验系统对CH4-O2-N2-H2O反应体系进行低温等离子体转化研究,分析水蒸气与CH4物质的量比、O2/N2物质的量比、放电电压、放电频率,以及气体总流量对CH4转化率及主要产物产率的影响。结果表明:CH4-O2-N2-H2O反应体系DBD的主要产物为H2、CO、CO2、C2H2、C2H4、C2H6和CH3OH;反应参数对CH4转化率和H2、CO、CO2、C2H6、CH3OH产率影响较为显著,而对C2H2、C2H4产率影响不显著;CH4转化率及主要产物产率均在放电频率为9.8 k Hz时取得最大值。展开更多
基金financially supported by the"Strategic Priority Research Program"of Chinese Academy of Sciences(No.XDA09030101)the National Natural Science Foundation of China(No.21103181 and 21473185)+1 种基金DICP Fundamental Research Program for Clean Energy(DICP M201301)Shaanxi Yanchang Petroleum Group Co.Ltd
文摘Long-term stability test of Mo/HZSM-5-N catalysts(HZSM-5-N stands for nano-sized HZSM-5) in methane dehydroaromatization(MDA)reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 1000 h.During this test,methane conversion ranges from 13% to 16%,and mean yield to aromatics(i.e.benzene and naphthalene) exceeds 10%.N2-physisorption,XRD,NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition,and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke,thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition.The effect of zeolite particle size on the catalytic activity was also explored,and the results showed that the nano-sized zeolite with low diffusion resistance performed better.It is recognized that the size effect was enhanced by reaction time,and it became more remarkable in a long-term MDA reaction even at a low space velocity.
文摘为提升瓦斯抽采利用率、促进煤矿安全生产,采用介质阻挡放电(DBD)试验系统对CH4-O2-N2-H2O反应体系进行低温等离子体转化研究,分析水蒸气与CH4物质的量比、O2/N2物质的量比、放电电压、放电频率,以及气体总流量对CH4转化率及主要产物产率的影响。结果表明:CH4-O2-N2-H2O反应体系DBD的主要产物为H2、CO、CO2、C2H2、C2H4、C2H6和CH3OH;反应参数对CH4转化率和H2、CO、CO2、C2H6、CH3OH产率影响较为显著,而对C2H2、C2H4产率影响不显著;CH4转化率及主要产物产率均在放电频率为9.8 k Hz时取得最大值。