NOVELTY - Continuous process for anaerobic bioconversion of a gas substrate comprising carbon monoxide, hydrogen and carbon dioxide in an aqueous menstruum containing microorganisms suitable for converting the substrate to alcohol, comprises: continuously contacting the substrate with the aqueous menstruum to bioconvert gas substrate to alcohol and providing an alcohol-containing menstruum and a depleted gas phase; continuously withdrawing the depleted gas phase from the aqueous menstruum; and continuously or intermittently withdrawing a portion of the menstruum for recovery of the alcohol.    USE - The processes are useful for continuous anaerobic bioconversion of gas substrate to alcohol, preferably ethanol (all claimed).    ADVANTAGE - The processes: provide higher alcohols with renewable carbon component, by maintaining the combination of high conversion and specific ratio of electron to carbon atoms; achieve high conversion efficiencies of hydrogen and carbon monoxide to alcohol; and are economical.    DETAILED DESCRIPTION - Continuous process for anaerobic bioconversion of a gas substrate comprising carbon monoxide, hydrogen and carbon dioxide in an aqueous menstruum containing microorganisms suitable for converting the substrate to alcohol, comprises: continuously contacting the substrate with the aqueous menstruum to bioconvert gas substrate to alcohol and providing an alcohol-containing menstruum and a depleted gas phase; continuously withdrawing the depleted gas phase from the aqueous menstruum; and continuously or intermittently withdrawing a portion of the menstruum for recovery of the alcohol, where the withdrawal is sufficient to maintain the alcohol in the menstruum below a concentration that unduly adversely affects the microorganisms, and at least two gases having different compositions are used as the gas substrate to provide an overall gas substrate having a ratio of electrons to carbon atoms of 5.2:1-6.8:1. INDEPENDENT CLAIMS are also included for:    (1) an alcohol derived from the anaerobic bioconversion of the gas substrate in which 20-70% of the carbon is from renewable carbon, the balance of the gas stream is made from non-renewable carbon, and the electrons to carbon atoms ratio is 5.8:1-6.4:1.14;    (2) a continuous process for the anaerobic bioconversion of the gas substrate in aqueous menstruum to alcohol, comprising (a) steam reforming hydrocarbonaceous feedstock to provide a syngas having an electron to carbon ratio greater than 7:1, where the steam reforming is performed in a steam reformer having at least one gas reforming section and at least one hotbox section, (b) continuously introducing the syngas and biogas into a bioreactor assembly, where the biogas comprises at least 20 or 25 mol.% carbon dioxide and at least 40 mol.% methane, and has an electron to carbon ratio not greater than 0.1:1 to provide an overall gas substrate having an electron to carbon ratio of 5.2:1-6.8:1, (c) continuously contacting the syngas and the biogas with the aqueous menstruum to bioconvert substrate gas to alcohol and providing the alcohol-containing menstruum and substrate depleted gas phase, where the contacting is in a bioreactor assembly containing the menstruum, (d) continuously withdrawing substrate depleted gas phase from the aqueous menstruum, where the depleted gas phase has a lower mole ratio of carbon dioxide to methane than that of the overall gas substrate, (e) passing at least a portion of the depleted gas phase to the steam reformer of step (a), and (f) continuously or intermittently withdrawing a portion of the menstruum for recovery of the alcohol;    (3) a continuous process for anaerobic bioconversion of the gas substrate in the aqueous menstruum to alcohol, comprising continuously introducing the gas substrate into the bioreactor assembly and providing the alcohol-containing menstruum and depleted gas phase, continuously withdrawing depleted gas phase from the aqueous menstruum, and continuously or intermittently withdrawing a portion of the menstruum for recovery of the alcohol, where the gas substrate as introduced into the bioreactor assembly has a ratio of electrons to carbon atoms of 5.2:1-6.8:1, the bioreactor assembly comprises at least two bioreactor stages in gas flow sequence in which at least the last bioreactor stage in gas flow sequence has a substantially uniform aqueous menstruum and a substantially non-uniform composition of the gas bubbles between the inlet portion and the outlet portion, and a carbon monoxide-containing gas having a ratio of electrons to carbon atoms less than 6.5:1 is introduced into the last bioreactor stage in an amount sufficient to provide a ratio of electrons to carbon atoms in the mixed gases of 5.2:1-7.5:1;    (4) an integrated process (I) for making alcohol from a combined gas substrate of carbon dioxide rich gas form an anaerobic fermentation of carbohydrates and a syngas gas substrate comprising carbon monoxide, hydrogen and carbon dioxide;    (5) a continuous, integrated process (II) for the anaerobic bioconversion of the gas substrate in the aqueous menstruum to alcohol;    (6) a continuous process for the production of alcohol from a combination of renewable and non-renewable gas streams, comprising combining a non-renewable gas with a renewable gas to produce a combined substrate comprising hydrogen, carbon monoxide and carbon dioxide in which 20-70% of the carbon is from renewable carbon, the balance of the gas stream is made from non-renewable carbon, and the electron to carbon atoms ratio is 5.5:1-6.4:1, contacting the substrate with a menstruum containing a biocatalyst in the form of microorganisms in an anaerobic fermentation zone and obtaining at least 85 mol.% conversion of the hydrogen, carbon monoxide and carbon dioxide of the substrate, continuously withdrawing a depleted gas phase from the aqueous menstruum, continuously or intermittently withdrawing a portion of the menstruum from the fermentation zone and recovering an alcohol product from the fermentation zone; and    (7) a continuous process for the anaerobic bioconversion of the gas substrate in the aqueous menstruum to an alcohol, comprising continuously passing the substrate and the menstruum through at least membrane module arranged within at least one bioreactor of a bioreactor assembly, maintaining a desired electron to carbon atoms ratio in each of the modules and, if necessary to maintain the desired electron to carbon atoms ratio in a module, adding at least one of carbon monoxide, carbon dioxide or hydrogen to the substrate gas inflow of that module, maintaining a desired alcohol concentration in each of the modules and withdrawing menstruum from at least one module and/or adding menstruum to at least one module, continuously withdrawing a substrate depleted gas phase from at least one of the modules, continuously or intermittently collecting a portion of the menstruum from the module for recovery of alcohol from it, and recovering alcohol from the collected menstruum.