Abstract: An apparatus and method are disclosed for the recovery of sensible heat from a hot tar-free gas produced in a coal gasification process and in combined-cycle power generation. The recovered heat is utilized to generate a flow of superheated steam which may be used in the gasification plant. The apparatus includes a first boiler and a superheater fabricated from materials susceptible to damage from thermal shock when a flow of the tar-free gas having a temperature in excess of a predetermined safety temperature is introduced to the superheater when it is dry. The first boiler, filled with a flow of saturated water, initially receives the flow of gas. Within the first boiler, the gas indirectly heats the water converting it to a flow of saturated steam and reducing the gas temperature below the safety temperature. The reduced temperature gas is passed to the superheater and the saturated steam is passed to the superheater.

Abstract: A method is disclosed for initiating operation of a coal gasification plant which includes a gasification reactor and gas cleansing apparatus fabricated in part from materials susceptible to chloride induced stress corrosion cracking the presence of oxygen. The reactor is preheated by combusting a stoichiometric mixture of air and fuel to produce an exhaust gas which is then diluted with steam to produce product gas which contains essentially no free oxygen. The product gas heats the reactor to a temperature profile necessary to maintain autothermic operation of the gasification process while maintaining air oxygen-free environment within the plant apparatus while chlorine is liberated from coal being gasified.