活性炭深度脱除硫化氢的研究进展

Research progress of hydrogen sulfide deep removal by activated carbon

活性炭深度脱除硫化氢气体是一项重要的环保技术,广泛应用于环保、化工、电子、能源、医药等各种工业过程中,也是活性炭的主要应用领域之一。系统阐述了活性炭、催化剂和吸附条件等对硫化氢吸附的影响规律,以及活性炭吸附脱除硫化氢的主要机制与关键步骤,全面总结了活性炭的生产方法、孔隙结构和表面化学性质对硫化氢吸附和催化转化的影响规律;比较分析了碱金属化合物、碱土金属化合物、重金属化合物等三类催化剂对活性炭吸附脱除硫化氢的促进作用机理,总结了气流的湿度、吸附温度、氨气、氧气及氧气含量、接触时间等吸附条件的影响;较为详细地阐述了吸附-溶解-氧化转化的活性炭吸附脱除硫化氢机制以及发生的相关反应,提出了活性炭深度吸附脱除硫化氢的前提与关键步骤,明确了活性炭、催化剂、吸附条件等影响活性炭深度脱除H 2 S的本质原因。最后,根据活性炭深度脱除硫化氢研究进展,并结合自身的科研实践,提出了今后深度脱除硫化氢用活性炭的主要发展方向及需要解决的问题。

Hydrogen sulfide(H_(2)S)is one of the major sulfur-containing pollutants because of its poison to catalysts and human health,unpleasant odor,and high corrosion to most equipment.Therefore,hydrogen sulfide removal in a stream is a vital desulfurization technology for gas purification and chemical conversion.Activated carbons have been widely used for removing hydrogen sulfide in a stream in the fields of environmental protection,chemical engineering,electrics,pharmacy and energy because of the advantages such as developed porosity,excellent physicochemical stability and availability.Here,the past ten-year advances of hydrogen sulfide deep removal technology by activated carbons from various aspects including activated carbon,catalysts,the chemical composition of a gas stream containing hydrogen sulfide,and adsorption parameters were comprehensively reviewed.In the aspect of activated carbon,this paper summarized the effect of the pore structure and physicochemical properties of activated carbons on hydrogen sulfide removal efficiency,with emphasis on the effect of surface chemistry of activated carbons on catalytic conversion of hydrogen sulfide in the adsorption process.Based on this information,the effect of the preparation methods of activated carbons on the removal performance was presented.In the aspect of catalysts,it was focused on three species of commonly loaded catalysts on activated carbons,including alkaline metal compounds,alkaline-earth metal compounds and heavy metal compounds,and conducted a comparative analysis about the promotion mechanism of deeply removing H_(2)S.In the aspect of adsorption parameters,the effect of adsorption temperature and contact time was involved.As to the chemical composition of the stream,the importance of the relative humidity and the oxygen and ammonia contents in the gas stream were highlighted.Then,this paper further reviewed the mechanism of hydrogen sulfide deep removal by activated carbons.An adsorption-dissolution-oxygen model was employed to explain the fact that activated carbons,catalysts and adsorption conditions significantly influence the H_(2)S deep removal.It was suggested the precondition and key steps for deeply removing hydrogen sulfide in a gas stream by activated carbons.Finally,the direction and major challenges for developing hydrogen sulfide deep removal technology by activated carbon in the future were proposed.