Kinetics of H2S removal using alkaline residue as in-bed sorbent in fluidized bed gasification of biomass and wastes

The use of alkaline residue from the acetylene industry (carbide slag, CS) as in-bed sorbent to remove H2S syngas biomass/waste fluidized bed (FB) gasification was investigated. Measurements were conducted in a laboratory FB applying differential conversion technique, tracking reaction using both gas measurements and solid analysis. Apparent kinetics obtained, without external mass transfer limitations, for different mixtures containing CO2, H2O, CO, H2 CH4, having relatively low concentration (500–1000 ppm). addition CO2 H2O an N2-H2-H2S mixture showed that rate reduced presence these species. Varying between 7 14% simple (N2-H2-H2S) reactive did not affect results, while CO potentially affected if also present gas. Other operating parameters, such particle size, sulfidation- calcination temperature CaO sulfidation rate, which increased with 800 900 °C enhanced by higher temperature. Specific surface area pore size distribution calcined CS measured before after reaction, showing maintained large fraction its original volume even most had been converted into CaS. limestone comparison slightly lower, but similar limestone, is promising alternative conventional calcium-based sorbents high removal, contributing promote circular economy, avoiding current stacking at production sites.