Peter H Benson, William S Wickersham: Solid fuel and process for combustion of the solid fuel. Speckman Pauley & Fejer, July 4, 1995: US05429645 (40 worldwide citation)

A solid fuel containing a recycled residue from anaerobic fermentation or anaerobic digestion of an organic material. The solid fuel can also contain a volatile solid fossil fuel. The residue is preferably derived from an anaerobic digestion process of municipal solid waste, raw sewage sludge, bioma ...