NOVELTY - Generating ethanol from biomass (2) comprises: gasifying biomass to generate syngas mixture (6) comprising carbon monoxide, carbon dioxide and hydrogen; fermenting at least majority of syngas mixture to produce ethanol via a fermentation process driven by a population of microorganisms, where carbon dioxide is produced as a by-product of fermentation; and directing at least majority portion of carbon dioxide produced during fermenting step into gasifying step, so as to (a) contribute as a component of motive and reactive gas in fluidized bed gasifier (3) and (b) enhance gasifying step.    USE - The method is useful for generating ethanol from biomass including wood, Sorghum, rice straw, switchgrass, Jatropha, algae, corn and/or sugarcane (claimed).    ADVANTAGE - In the method, the carbon dioxide produced during the fermentation of syngas is directed into the gasifier, where it enhances carbon monoxide production and mitigates char production, which in turn increases ethanol production with high level of flexibility, adaptability and self-sufficiency.    DETAILED DESCRIPTION - Generating ethanol from biomass (2) comprises: gasifying biomass to generate a syngas mixture (6) comprising carbon monoxide, carbon dioxide and hydrogen, where the gasifying is carried out in a fluidized bed gasifier using a motive and reactive gas stream comprising a mixture of gases; fermenting at least majority of the syngas mixture to produce ethanol via a fermentation process driven by population of microorganisms, where carbon dioxide is produced as a by-product of the fermentation; and directing at least majority portion of the carbon dioxide produced during the fermenting step into the gasifying step, so as to contribute as a component of the motive and reactive gas in the fluidized bed gasifier (3) and (b) enhance the gasifying step, via an equilibrium shift, to increase the production of carbon monoxide and decrease the production of char. An INDEPENDENT CLAIM is also included for a system to generate ethanol from biomass comprising: a source of biomass amenable to gasification; a fluidized bed gasifier in processable communication with the source of biomass and operable for gasifying the biomass, and comprising an integral heating means; a motive and reactive gas mixture supply and stream in processable communication with the fluidized bed gasifier, where the motive and reactive gas is operable for reacting with the biomass in the gasifier to yield a syngas mixture; a fermenting chamber (9) comprising a population of microorganisms suitable for effecting the fermentative transformation of syngas to a fermentation product comprising ethanol and carbon dioxide, where the fermenting chamber is in processable communication with the gasifier, so that fermenting chamber can receive the syngas produced from gasifier; and a separator (15) in processable communication with the fermenting chamber, where the separator is operable for separating carbon dioxide from a residual fermentation product balance, and the separator is in processable communication with the motive and reactive gas mixture supply and stream, so that at least majority of the carbon dioxide produced in the fermenting chamber is incorporated as a component of the motive and reactive gas mixture supply and stream.    DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of a system that integrates a biomass gasifier with a syngas fermentation chamber, and optionally a photosynthetic biomass growth chamber.    Biomass (2)    Fluidized bed gasifier (3)    Syngas mixture (6)    Fermenting chamber (9)    Separator (15)