硫化氢催化氧化技术的研究进展

Research progress of catalytic oxidation technologies of hydrogen sulfide

随着经济的发展以及人们对环保的重视,国家层面对硫化氢(H2S)的排放进行了严格的规定。因此,对H2S的去除材料成为研发重点。催化氧化技术是去除H2S的主要方法,目前研究较为深入的催化剂有炭基催化剂(包括无负载活性炭)、金属负载活性炭和金属氧化物催化剂(包括金属氧化物负载催化剂、金属氧化物催化剂和阴离子黏土负载催化剂)。详细介绍了2种催化剂的催化氧化原理、制备方法、去除效果和应用前景:炭材料由于其巨大的比表面积、高孔隙率和可以改性的表面活性位是催化剂或载体的热门选择,而炭基催化剂具有相对较低的操作温度和良好的稳定性,不需要遵循严格的O2和H2S化学计量比,但只能处理低浓度H2S,且要求在较低的空速下进行,催化剂必须定期进行再生;金属氧化物催化剂可以处理高浓度H2S,且在较高的温度(200~300℃)下有良好的催化性能,但由于其操作过程需要遵循严格的O2和H2S化学计量比和较高的温度,且再生性能差,因此成本较高;富氮多孔炭和负载碱金属的碱性毫米级中孔炭球(MCS)表现出优异的催化性能。在此基础上,对H2S催化氧化技术的发展方向进行了展望。

With the development of the economy and increasingly regard on environment protection,a series of measures were formulated and strict regulations on hydrogen sulfide(H2S)emission were established by the state.The removal of H2S has been the focus of material research and development,and catalytic oxidation is considered as a main method for H2S removal.Two kinds of catalysts including carbon-based catalysts(unsupported activated carbon,metal-supported activated carbon)and metal oxide-based catalysts(oxide-supported catalyst,metal oxide catalyst,anionic clay-supported catalyst)have been widely studied.The catalytic oxidation mechanism of H2S,preparation method for these two catalysts and H2S removal efficiency as well as the potential applications of these catalysts were discussed in detail.Carbon materials had become a popular choice as catalyst or support due to their large specific surface area,high porosity and modifiable active sites.Meanwhile,they were usually operated at relatively low temperatures and showed a good stability,and no strict stoichiometric ratios of O2/H2S was needed during H2S treatment process.However,such catalysts could only treat low concentrations of H2S and operated at lower hourly space velocity.In addition,the catalysts should be regenerated periodically after a period of use.As for metal oxide catalyst,they could treat high concentrations of H2S and showed a good catalytic performance even at higher temperatures(200-300℃),but the cost of the catalysts was high due to the strict O2/H2S stoichiometric ratio,high temperature and poor regenerability.Nitrogen-rich porous carbon and alkali metal-loaded alkaline millimeter mesoporous carbon spheres(MCS)exhibited excellent catalytic performance.On this basis,the future development direction of H2S catalytic oxidation was addressed.