NOVELTY - The process comprises supplying a first carbonaceous feedstock to a gasification reactor (21), partially combusting the first feedstock in the reactor in the presence of oxygen and under suitable temperature and pressure, generating steam using the heat energy from the combustion of the first feedstock, introducing a portion of the steam, the combustion gas stream, a second carbonaceous feedstock and a gasification catalyst to the reactor, reacting the second feedstock in the reactor in the presence of steam and the catalyst, and contacting the first gas stream with an aqueous medium.    USE - The process is useful for converting a carbonaceous feedstock into gaseous products contained in a gas stream, and for separating hydrogen and methane from other gaseous products in the gas stream (claimed), where the carbonaceous feedstock includes petroleum coke, liquid petroleum residue, asphaltene, biomass and/or coal to combustible gases such as methane.    ADVANTAGE - The process ensures inexpensive and efficient conversion of carbonaceous feedstock into gaseous products contained in a gas stream thus increasing the potential yield of hydrogen gas.    DETAILED DESCRIPTION - The process comprises supplying a first carbonaceous feedstock to a gasification reactor (21), partially combusting the first feedstock in the reactor in the presence of oxygen and under suitable temperature and pressure so as to generate heat energy and a combustion gas stream comprising hydrogen, carbon monoxide, and carbon dioxide, generating steam using the heat energy from the combustion of the first feedstock, introducing a portion of the steam, the combustion gas stream, a second carbonaceous feedstock and a gasification catalyst to a gasification reactor, reacting the second feedstock in the reactor in the presence of steam and the catalyst and under suitable temperature and pressure to form a first gas stream comprising methane, hydrogen, carbon monoxide, carbon dioxide and one or more additional gaseous byproducts, contacting the first gas stream with an aqueous medium to convert a portion of the carbon monoxide to carbon dioxide and to generate hydrogen for forming a carbon monoxide-depleted gas stream comprising methane, hydrogen, carbon dioxide and one or more additional gaseous by-products, removing a portion of the carbon dioxide and the additional gaseous by-products from the carbon monoxide-depleted gas stream to form a second gas stream comprising methane and hydrogen, and partially separating the hydrogen and methane in the second gas stream from each other to form a hydrogen-enriched gas stream and a first methane-enriched gas stream. The first methane-enriched gas stream comprises methane, optionally carbon monoxide, and up to about 4 mol.% of hydrogen and in which, if the heating value of the first methane-enriched gas stream is less than 950 British thermal unit/standard cubic feet (btu/scf) (dry basis), and if the first-methane-enriched gas stream comprises greater than or equal to 1000 ppm of carbon monoxide: partially separating carbon monoxide from the first methane-enriched gas stream to form a carbon-monoxide-enriched gas stream and a second methane-enriched gas stream having a heating value of 950 btu/scf (dry basis); or partially methanating the carbon monoxide in the first methane-enriched gas stream to form a second methane-enriched gas stream. The gasification catalyst is an alkali metal gasification catalyst and recycled from the catalyst recovery and recycle process. A char is formed in the reacting step, and the char is removed from the gasification reactor and sent to a catalyst recovery and recycle process. The first carbonaceous feedstock, the second carbonaceous feedstock, or both the first carbonaceous feedstock and the second carbonaceous feedstock are in a particulate form. The first carbonaceous feedstock is in the form of an aqueous slurry. The reactor is either a gasification reactor or an oxygen combustor. In the generating step: the steam is generated within the reactor; and the heat energy is transferred to a heat exchanger, which generates steam upon contact with water. The process comprises introducing a portion of the steam into a steam turbine to generate electricity. All of the steam generated in the generating step is introduced into the gasification reactor.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram that illustrates a continuous process for gasification of a carbonaceous feedstock.    Catalyst recovery unit (4)    Oxygen blown gasifier (7)    Gasification reactor (21)    Shift reactor (22)    Gas purification unit. (23)