Textural and hydrogen sulphide adsorption behaviour of double metal-silca modified with potassium permanganate

• Published in: Journal of porous materials Vol. 20; no. 3; p. 447
• Main Authors: Twumasi Afriyie, Ebenezer, Norberg, Peter, Sjöström, Christer, Forslund, Mikael
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: H2S adsorption; Hydrogen sulphide; KMnO4 impreganation; Pore size; Textural properties
• ISSN: 1573-4854; 1380-2224
• DOI: 10.1007/s10934-012-9614-x

A new MgCa–silica material with bimodal pore size is impregnated with KMnO 4  for dynamic adsorption of H 2 S. The MgCa–silica was synthesized using sodium silicate and calcium and magnesium salts as precipitating agents. The KMnO 4  impregnation onto MgCa–silica was obtained through either direct addition into MgCa–silica wet coagulum or doping of dried MgCa–silica pellets into KMnO 4  solution. These chemisorbents were characterized by nitrogen physisorption, spectrophotometer, microscopy and dynamic H 2 S adsorption test setup similar to ASHRAE standard I45.I. The results show that impregnation route and KMnO 4  wt% cause a reduction of surface area and total pore volume. The decrease in pore volume was slightly more in chemisorbents obtained via post doping compared to direct impregnation. Regardless of pore volume reduction the pore size range, 1–32 nm, was as in the parent MgCa–silica with micro and meso-pore diameter centered at 1.4 and 5.4 nm respectively. Thus obtained chemisorbents have their pore entrances neither blocked nor shifted. The MgCa–silica/KMnO 4  chemisorbents exhibits good H 2 S uptake performance. The chemisorbent with 11.4 wt% KMnO 4  and obtained via direct impregnation possesses the highest uptake capacity. The lowest capacity was observed for chemisorbent with 8 wt% KMnO 4  and made by direct impregnation. The variations in uptake capacity are likely due to impregnation route, the KMnO 4  content and its location in the pore system. The results suggest that the MgCa–silica/KMnO 4 chemisorbents can remove H 2 S from indoor air at room temperature.