Hydrogen sulfide removal from biogas by bio-based iron sponge

The iron sponge process, a technology used for removing hydrogen sulphide (H2S) from biogas, can potentially use various biodegradable wastes as the supporting material for the H2S adsorption media, providing improved flexibility and cost-effectiveness. In this study, ground garden waste, digested garden waste, and spent tobacco were evaluated as supporting materials of the H2S adsorption media. It was found that both particle size and moisture content had significant effects on H2S removal performance when ground garden waste was used. The optimum moisture content of the ground garden waste system was determined to be 15%. The optimum moisture content for the digested garden waste system was found to be 25%. Iron sponge with either ground garden waste or digested garden waste at their optimum conditions had an H2S removal performance comparable to a commercial product (SulfaMaster™). Iron sponge using spent tobacco, however, was found to be only about 20% as efficient as SulfaMaster™. Ground or digested garden waste could be an alternative supporting material for the iron sponge system.