Patent ID: 7687161

Claim:
A method for concurrent production of electrical power and biomass, and consumption of carbon dioxide (CO 2 ), comprising; a) pumping a fluid containing oxygen and carbon dioxide into a bioreactor containing chemolithotrophic microorganisms and dissolved nutrients to facilitate growth of the chemolithotrophic microorganisms, said bioreactor being in flow communication with a cathode compartment, the cathode compartment including a cathode electrode and a redox couple Fe 2+ /Fe 3+ with a reaction at the cathode electrode being reduction of a first member Fe 3+ of the redox couple to a second member Fe 2+ of the redox couple in a lower oxidation state with a chemical reaction being 4Fe 3+ +4e − ═4Fe 2+ ; b) pumping fuel into an anode compartment containing an anode electrode with the fuel having a hydrogen constituent, said anode compartment being separated from said cathode compartment by a proton exchange membrane, a reaction at the anode electrode being electrochemical oxidation of at least the hydrogen constituent of the fuel to produce electrons (e − ) and protons (H + ), wherein protons (H + ) formed by the oxidation of the fuel cross the proton exchange membrane into the cathode compartment; c) pumping an aqueous solution containing ferrous ions (Fe 2+ ) and protons (H + ) from the cathode compartment to the bioreactor where the ferrous ions (Fe 2+ ) are oxidized by the chemolithotrophic microorganisms to ferric ions (Fe 3+ ) in an aerobic oxidation reaction given by 4Fe 2+ +4H + O 2 ═4Fe 3+ +2H 2 O, wherein biomass production and carbon dioxide consumption responsively occurs due to fixation of the carbon dioxide (CO 2 ) by the chemolithotrophic microorganisms in the presence of the dissolved nutrient salts and the Fe 2+ ; and d) pumping the aqueous solution containing the Fe 3+ oxidized by the chemolithotrophic microorganisms in said bioreactor into said cathode compartment; wherein electrical power in an electrical load is obtained by making electrical connection between the electrical load and the anode and cathode electrodes.