NOVELTY - Converting biomass to methane and light hydrocarbons with low levels of depositable tars, comprises: (a) a fast pyrolysis (2) of lignocellulosic biomass (1) using a hydrogen containing sweep gas (4) to produce a hot pyrolysis gas mixture and a by-product containing char (5) and ash; (b) passing the gas mixture through a first section of a catalytic reactor to form a methane, steam and light hydrocarbon enriched gas stream; (c) providing an extended gas residence time within a second section of the catalytic reactor; and (d) cooling and separating the gas stream.    USE - The method is useful for converting biomass to methane and light hydrocarbons with low levels of depositable tars. The method is useful for hydro-gasification of biomass feed stocks, such as lignocellulosic materials, including forestry residues or lignocellulosic waste materials, to generate higher value hydrocarbon fuels, preferably methane and aromatic and/or phenolic compounds with low levels of depositable tars.    ADVANTAGE - The method: converts biomass into a useful fuel which avoids the formation of deposits downstream of thermochemical reactors; and reduces depositable tars without the addition of oxidative gases or superheated steam.    DETAILED DESCRIPTION - Converting biomass to methane and light hydrocarbons with low levels of depositable tars, comprises: (a) a fast pyrolysis (2) of lignocellulosic biomass (2) using a hydrogen containing sweep gas (4) at a temperature of 400-600 degrees C and at an elevated pressure of 3-50 atmosphere (atm) to produce a hot pyrolysis gas mixture and a by-product containing char (5) and ash; (b) passing the hot pyrolysis gas mixture containing hydrogen through a first section of a catalytic reactor to form a methane, steam and light hydrocarbon enriched gas stream at a temperature above in step (a) and less than 650 degrees C without the addition of air or oxygen to induce the temperature rise; (c) providing an extended gas residence time within a second section of the catalytic reactor and at a temperature above in step (a) and below 650 degrees C; and (d) cooling and separating the gas stream to output a useful methane-rich fuel gas and by-product condensed light hydrocarbons and light oxygenates.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic flow chart for converting biomass to methane and light hydrocarbons.    Biomass (1)    Pyrolysis (2)    Hydropyrolysis reactor (3)    Sweep gas (4)    Char. (5)