pH of activated carbon surface as an indication of its suitability for H2S removal from moist air streams

Samples of activated carbons of different origins were tested as removers of hydrogen sulfide at room temperature. The breakthrough capacity was evaluated using a lab designed test. The surface properties of the carbons were studied using Boehm titration, nitrogen sorption and thermal analysis. The results obtained indicate that the choice of unimpregnated carbon for hydrogen sulfide removal should be based on the parameters describing surface acidity such as pH, number of acidic groups, or weight loss during thermal treatment associated with the presence of acidic functional groups. There are certain threshold ranges of these quantities which, when exceeded, have a dramatic effect on the H2S breakthrough capacity. (C) 2001 Elsevier Science Ltd. All rights reserved.