NOVELTY - Method (M1) for increasing conversion of biomass-based lignocellulosic materials in a biotreatment process, comprises: (a) subjecting the lignocellulosic materials to a low-temperature, long-time pyrolysis to produce a pyroligneous acid, a pyrogas (containing methane, carbon monoxide, hydrogen and water), and pyrosolids including char, ash, and residual lignin-containing materials; (b) separating the pyroligneous acid, pyrogas and pyrosolids; and (c) subjecting the pyroligneous acid to an anaerobic biological treatment step to produce at least one of a methane-bearing biogas and ethanol.    USE - The method is useful for increasing the conversion of biomass-based lignocellulosic materials in a biotreatment process to produce at least one of a methanaceous fuel gas and ethanol (claimed).    ADVANTAGE - The method: utilizes waste and low grade materials such as sewage sludge, wood, cellulosic waste, municipal solid wastes, low grade coal, lignite and other biomaterials to convert them at high efficiency to fuel gases, ethanol and/or other energetic liquid fuels or commercial chemicals; reduces carbon dioxide emissions; recycles pyroligneous acid, thus enhancing the yield of fuels; reduces quantity of volatile materials; and reduces the raw material cost for ethanol fermentation and treatment costs of waste materials.    DETAILED DESCRIPTION - Method (M1) for increasing the conversion of biomass-based lignocellulosic materials in a biotreatment process, comprises: (a) subjecting the biomass-based lignocellulosic materials to a low-temperature, long-time pyrolysis to produce a pyroligneous acid (where a portion is comprised of wood alcohol and wood vinegar), a pyrogas (containing methane, carbon monoxide, hydrogen and water), and pyrosolids including char, ash, and residual lignin-containing materials; (b) separating the pyroligneous acid, pyrogas and pyrosolids; and (c) subjecting the pyroligneous acid to an anaerobic biological treatment step to produce at least one of a methane-bearing biogas and ethanol. An INDEPENDENT CLAIM is also included for a method (M2) for enhancing the anaerobic treatment of a first lignocellulose-containing material, comprising: introducing a first lignocellulose-containing material to an anaerobic biotreatment step, where methanogenic microorganisms produce a methane-containing biogas and an aqueous stream containing residual biosolids; separating the biogas from the aqueous stream containing biosolids; dewatering the residual biosolids; subjecting the residual biosolids materials to a low-temperature, long-time pyrolysis to produce a pyrolysis product; condensing the pyrolysis product to produce a liquid pyroligneous acid (where a portion is comprised of wood alcohol and wood vinegar), a pyrogas (containing methane, carbon monoxide, hydrogen and water), and pyrosolids including char and ash materials; the step (b) as above per se; introducing the pyroligneous acid to the biotreatment step; introducing at least a portion of the pyrogas to the biotreatment step, where the introduced pyrogas portion mixes with the biogas produced in the biotreatment step; and separating and removing the mixed pyrogas and biogas for use as a fuel gas.