NOVELTY - Process for reforming hydrocarbon feedstock to produce methane comprises: (a) mixing supercritical water (SCW) and hydrocarbon feedstock to form liquid reactant mixture; (b) contacting liquid reactant mixture with catalyst; (c) maintaining mixture formed in step (a) in supercritical state in heated reactor; and (d) recovering methane produced in step (b), where catalyst (I) is a ruthenium-based catalyst in a reduced form or in an oxide form, nickel-based catalyst in reduced form, or combined ruthenium-based and nickel based catalyst and feedstock is methanol, ethanol, butanol and/or acetane.    USE - The process is useful for: reforming a hydrocarbon feedstock comprising methanol, ethanol, butanol and/or acetane to produce methane; converting an organic feedstock to methane; fueling a motorized vehicle having an ethanol-fueled internal combustion engine; conversion of ethanol to methane (all claimed), where the methane is useful as a raw material in power plants as a combustible fuel, in combustion engine for vehicle and in power generation as well as in gas turbines.    ADVANTAGE - The process provides methane which has a much higher energy density than hydrogen.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) system for reforming a feedstock into methane comprising: (a1) a water feed and the feedstock feed; (b1) a SCW reactor in fluid communication with the water feed and the feedstock feed, where the SCW reactor contains the catalyst (I); and (c1) a methane capturing device;    (2) process for converting an organic feedstock to methane, comprising: reforming the organic feedstock using SCW in the presence of the catalyst (I) at 350-600 degrees C for selected reaction time so that the ethanol and the SCW react to produce a gas mixture comprising at least 34% methane; and capturing the gas mixture;    (3) process of fueling a motorized vehicle having an ethanol-fueled internal combustion engine, comprising: reforming ethanol using SCW in the presence of the catalyst (I) at 350-600 degrees C for selected reaction time so that the ethanol and the SCW react to produce a gas mixture including at least 40% methane; and capturing the methane produced in the reactor and feeding the methane to the internal combustion engine;    (4) process for conversion of ethanol to methane, comprising either: reforming ethanol by contacting the ethanol with SCW in the presence of the catalyst (I) at 400-600 degrees C for a selected reaction time so that the ethanol and the SCW react to produce methane gas, carbon dioxide gas and water vapor as given in the reaction (CH3CH2OH + 3H2O to give 1.5 CH4 + 0.5 CO2 + 3H2O); or reforming ethanol by contacting the ethanol with SCW in the presence of a catalyst (II) comprising iron, cobalt, nickel, ruthenium, rhodium, palladium and/or platinum, at 350-600 degrees C for selected reaction time so that the ethanol and the SWC react to produce a gas mixture including at least 40% methane;    (5) a bi-metallic catalyst comprising 5-25% nickel and 1-5% ruthenium supported on alumina, including gamma -alumina; and    (6) method for producing the bi-metallic nickel-ruthenium catalyst comprising either: (a2) adding a solid support to an aqueous solution of a water soluble salt of nickel and an aqueous solution of a water soluble salt of ruthenium, where the solid support is thermally/chemically stable in SWC, (b2) mixing the suspension resulting from step (a2), (c2) heating the mixed suspension from step (b) under reduced pressure to remove the water, (d2) drying the product of in an oven, and (e2) calcining the solid product of step (d2); or steps (a2)-(c2) as above per se; (d3) adding the solid support impregnated with nickel or ruthenium to an aqueous solution of the other of the water soluble salt of nickel or the a water soluble salt of ruthenium that was not already mixed with the solid support; (e3) mixing the suspension resulting from step (d3); (f3) heating the mixed suspension from step (f3) under reduced pressure to remove the water; (g3) drying the product of step (f3) in an oven; and (h3) calcining the solid product of step (g3).