Oxidation of hydrogen sulfide over microporous carbons

✍ Scribed by O.C. Cariaso; P.L. Walker Jr.

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 749 KB
• Volume: 13
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(75)90237-7

✦ Synopsis

Microporous carbon of high purity was produced by the carbonization of Saran at 900" followed by activation in either CO2 at 900", Oz at 300", or air at 425". The activated carbons were characterized using N2 adsorption at -195", COZ adsorption at 25", and mercury and helium displacements. Hydrogen sulfide oxidation (at H,S pressures between 04-3.8 Torr) by 0, (in excess of stoichiometric amount) was studied between 10&160" using a microbalance, that is by weighing the build-up of sulfur on the carbon. The predominant reaction. HLS + f 0,-i SZ+H20 was first order in H,S concentration and independent of O2 concentration. The rate was only slightly reduced by sulfur build-up to at least 36%, by weight, on the carbon. The oxidation rate was significantly higher over the O,-activated carbon than over the C02-activated carbon. Throughout the studies, oxidation rates could be correlated with area active to O2 chemisorption. It is concluded that HZS oxidation proceeds via rapid dissociative chemisorption of oxygen on carbon sites followed by reaction with HIS. Rates of H2S oxidation were also studies over commercial, granular activated carbons of significant ash contents.