A process for obtaining energy values contained in a sulphur-containing carbonaceous fuel, the process comprising (a) treating a feed carbonaceous fuel having a first bound-sulphur content with an effective amount of an oxygen and SO.sub.2-containing gas in a reactor at an effective temperature to (i) provide elemental sulphur from the SO.sub.2, (ii) release exothermic heat, and (iii) produce a hot effluent gaseous steam containing the elemental sulphur and treated fuel having a second bound-sulphur content, (b) separating the elemental sulphur from the treated fuel; (c) collecting the elemental sulphur; (d) collecting the treated fuel; and (e) collecting the exothermic heat.