Adsorption of H2S on residual biomass gasification char

Char is the solid by-product of biomass gasification. Plant owners usually dispose of it at a cost, but its high carbon content and surface area could make it suitable for further applications. In this work, we studied its potential to adsorb hydrogen sulphide (H2S), a common pollutant, e.g. present in the producer gas of gasification, as well as in biogas from anaerobic digestion. We tested different samples of char collected from commercial gasification plants in South Tyrol (Italy). The adsorption was reproduced in a lab-scale fixed bed reactor. The results highlights that all samples could capture hydrogen sulphide, showing different adsorption performance. The surface area of the char and the ash amount seem to affect the removal capacity, although other properties of the materials are probably important. The inlet concentration of hydrogen sulphide does not influence the adsorption capacity significantly.