Cornell university plant scientists have invented a new method that uses manure and other farm byproducts to remove hydrogen sulfide from the biogas produced by anaerobic digesters.

Most methods for hydrogen sulfide removal require expensive industrial scrubbers that are not feasible for on-farm use. However, this process uses manure as a major component of a special medium that is placed in barrels. The gas is then piped into the bottom of the barrel, and as it passes through the medium, the hydrogen sulfide is removed. The resulting clean methane (plus carbon dioxide) can be used for energy. On-farm tests have been promising.