Low temperature H2S removal with 3-D structural mesoporous molecular sieves supported ZnO from gas stream

• Published in: Journal of hazardous materials 2016-07, Vol.311, p.142-150
• Main Authors: Li, L., Sun, T.H., Shu, C.H., Zhang, H.B.
• Format: Article
• Language: English
• Subjects: 3-D mesoporous molecular sieves; Adsorption; Agglomeration; H2S; KIT-6; Molecular sieves; Porosity; Surface chemistry; Three dimensional; Wetness; Zinc oxide; ZnO
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2016.01.033

•Different structural 3-dimentional mesoporous silica materials was synthesized and supported ZnO for H2S removal at low temperature.•KIT-6 supported different ZnO loadings shows high breakthrough sulfur capacity with high structural stability.•Pore volume and pore size are more important to impact the adsorption capacity compared to surface area.•The microporosity induced by connection of cavities and complementary pores influences the mass transfer after ZnO loading. A series of 3-dimensional (3-D) structural mesoporous silica materials, SBA-16, MCM-48 and KIT-6, was synthesized and supported with different ZnO loadings (10, 20, 30, and 40wt%) by the incipient wetness method to evaluate the performances on H2S removal at room temperature. These materials were characterized by N2 adsorption, XRD, and TEM to investigate their textural properties. All the ZnO-loaded adsorbents exhibited the H2S removal capacity of bellow 0.1 ppmv. With the best ZnO loading percentage of 30wt% on MCM-48 and KIT-6, 20wt% on SBA-16 according to the results of breakthrough test, further increasing ZnO loading caused the decrease of the adsorption capacity due to the agglomeration of ZnO. Besides, the H2S adsorption capacities of the supports materials varied in the order of KIT-6>MCM-48>SBA-16, which was influenced primarily by their pore volume and pore size. With the largest pores in these 3-D arrangement materials, KIT-6 showed the best performance of supported material for ZnO, due to its retained superior physical properties as well as large pore diameter to allow faster gas-solid interaction and huge pore volume to disperse ZnO on the surface of it.