A method for generating energy and/or fuel from the halogenation of a carbon-containing material and/or a sulfur-containing chemical comprises supplying the carbon-containing material (e.g., coal, lignite, biomass, cellulose, milorganite, methane, sewage, animal manure, municipal solid waste, pulp, paper products, food waste) and/or the sulfur-containing chemical (e.g., H.sub.2S, SO.sub.2, SO.sub.3, elemental sulfur) and a first halogen-containing chemical to a reactor. The carbon-containing material and/or the sulfur-containing chemical and the halogen-containing chemical are reacted in the reactor to form a second halogen-containing chemical and carbon dioxide, sulfur and/or sulfuric acid. The second halogen-containing chemical is dissociated (e.g., electrolyzed) to form the first halogen-containing chemical and hydrogen gas (H.sub.2). The first halogen-containing chemical can be Br.sub.2 and the second halogen-containing chemical can be HBr. Any carbon dioxide formed during reaction can be directed to a prime mover (e.g., turbine) to generate electricity. Any ash and/or sulfur formed can be removed. In some cases a sulfur-containing chemical can be supplied to the reactor with the carbon-containing material.