NOVELTY - Producing at least one hydrocarbon product, comprises: (a) providing a substrate comprising carbon monoxide to a bioreactor (2) containing a culture of at least one microorganism; and (b) fermenting the culture in the bioreactor to produce the hydrocarbon product, where the substrate of step (a) is derived from an industrial process comprising steam reforming processes, refinery processes, steam cracking processes or reverse water gas shift processes.    USE - The method is useful for producing hydrocarbon product, where the hydrocarbon is ethanol, 2,3-butanediol, acetate, ethanol, propanol, butanol, butyrate, propionate, caproate, propylene, butadiene, isobutylene or ethylene (claimed).    ADVANTAGE - The method: can be easily performed; is robust to the substrates utilized with impurities and differing gas concentrations; reduces the concentration of carbon monoxide in the substrate and concentrates hydrogen, thus enabling improved hydrogen recovery; and provides the hydrocarbon product which can be easily transported and delivered in a usable form to industrial, commercial, residential and transportation end users resulting in increased energy efficiency and convenience.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a system for the production of the hydrocarbon product, comprising: (i) a bioreactor containing a culture of at least one microorganism adapted to produce the hydrocarbon product by fermentation of a carbon monoxide and/or hydrogen containing substrate, where the bioreactor is adapted to receive the carbon monoxide and/or hydrogen containing substrate from an industrial process; (ii) a substrate production stage adapted to provide a substrate comprising carbon monoxide and/or hydrogen to the bioreactor, where the substrate production stage including an industrial process is a steam reforming module (4), refinery process module, steam cracking module or reverse water gas shift module (6); and (iii) a means for supplying a substrate comprising carbon monoxide and/or hydrogen from an industrial process of (ii) to the bioreactor of (i).    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the system and method of producing the hydrocarbon product.    Bioreactor (2)    Steam reforming module (4)    Water gas shift module (6)    Pressure swing adsorption module (8)    Digestion module (10)