NOVELTY - A method (M1) of gasification of carbonaceous materials in a gasifier to produce a product gas comprising carbon monoxide, hydrogen, and tar; involves adding at least one carbonaceous material (150); adding a molecular oxygen-containing gas (220), adding a methane-containing gas and optionally adding water or steam into the gasifier. The amount of total oxygen added to the gasifier in pounds per pound of total carbon added to the gasifier is greater than about 0.75.    USE - For gasification of carbonaceous materials to produce a product gas comprising carbon monoxide, hydrogen, and tar and bioconversion of syngas to produce an alcohol product mixture. The carbonaceous materials is selected from carbonaceous material, carbonaceous liquid product, industrial carbonaceous liquid recycle, carbonaceous municipal solid waste (MSW), carbonaceous urban waste, carbonaceous agricultural material, carbonaceous forestry material, carbonaceous wood waste, carbonaceous construction material, carbonaceous vegetative material, carbonaceous petrochemical coproducts, carbonaceous coal, plastic, waste plastic, coke oven tar, fibersoft, tires, lignin, black liquor, polymers, waste polymers, polyethylene terephthalate (PETA), polystyrene (PS), sewage sludge, animal waste, crop residues, energy crops, forest processing residues, wood processing residues, livestock waste, poultry waste, food processing residues, fermentative process wastes, carbonaceous industrial waste, alcohol production wastes, ethanol coproducts, spent grains and/or spent microorganisms (all claimed). The syngas produced is used in production of power or chemicals. The alcohol includes methanol, ethanol, propanol or butanol.    ADVANTAGE - The method of operation of gasifier maximizes production of power or chemicals from the syngas produced from gasifier while keeping amount of un-reacted or unconverted carbon particles or soot in the raw syngas and amount of un-reacted carbon in ash under desirable low values especially when a methane-containing gas is co-gasified with carbonaceous material feed.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method (M2) of gasification of carbonaceous materials (150) in a gasifier using partial oxidation to produce syngas in a gasifier, where the gasifier comprises two reaction zones involving adding the carbonaceous materials into first reaction zone (200) of gasifier; and adding molecular oxygen containing gas (220), a methane-containing gas and optionally water or steam into one or both of the first reaction zone and second reaction zone (400). The amount of total oxygen added to the gasifier in pounds per pound of total carbon added to the gasifier is greater than about 1.25.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of a two-stage gasifier using partial oxidation.    Carbonaceous material (150)    First reaction zone (200)    Molecular oxygen containing gas (220)    Stream of ash (250)    Second reaction zone (400)