The adsorption of hydrogen cyanide by impregnated activated carbon cloth. Part I: Studies on cobalt and nickel acetates as impregnants for hydrogen cyanide removal

✍ Scribed by J.F. Alder; P.R. Fielden; S.J. Smith

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 906 KB
• Volume: 26
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(88)90074-7

✦ Synopsis

Activated carbon cloth is impregnated by dipping in solutions of cobalt acetate or nickel acetate to give a range of loadings. Prepared cloths were used to form filter beds, 20 layers thick, which were exposed to hydrogen cyanide (HCN)-laden air. Challenge concentration was 2 mg L-' HCN in air at 80% relative humidity, at ambient temperatures of 20 to 25°C. Breakthrough times were measured by gas chromatography and were dependent upon impregnant loading of the charcoal, with a typical value of 25 min at 16% (w/w) anhydrous metal acetate loading. At this loading, a typical capacity figure is 90 mg HCN g-' (charcoal + impregnant) before breakthrough with a CN-Co or CN-Ni molar ratio between 3 and 4. Breakthrough time performance was maintained for at least one year, on storage under ambient conditions. The mechanism of reaction is believed to be dissolution of HCN into a saturated solution of metal acetate on the carbon surface, with subsequent formation of metal-cyanide complexes and insoluble precipitates. Key WordsCarbon cloth, adsorption, hydrogen cyanide, cobalt acetate. nickel acetate.