Patent ID: 8450015

Claim:
A fuel cell bioreactor for producing electrical power, comprising; a) a vessel containing metal ion-oxidizing microorganisms and a catholyte, the catholyte containing a redox couple with a first member of the redox couple in a higher oxidation state than a second member of the redox couple; b) a cathode electrode immersed in the catholyte in the vessel; c) an anode electrode assembly immersed in the catholyte in the vessel, the anode assembly including a membrane anode assembly which includes a proton conducting membrane attached to an anode electrode, the anode electrode assembly including a current collector physically contacting the anode electrode, the current collector and the anode electrode being configured to form an anode compartment therebetween, the anode electrode assembly including an insulating housing into which the current collector and the anode electrode are inserted to seal the anode electrode and the current collector from the catholyte such that the anode electrode assembly is configured so that the anode compartment is separated from said catholyte by the proton conducting membrane; d) a first fluid feed mechanism for feeding a fluid containing oxygen (O 2 ) and carbon dioxide into the catholyte; e) a second fluid feed mechanism for feeding a fuel containing a hydrogen constituent into said anode compartment, wherein a reaction at the cathode electrode is reduction of the first member of the redox couple in a higher oxidation state to the second member of the redox couple in a lower oxidation state, and wherein a reaction at the anode electrode is electrochemical oxidation of the fuel to produce electrons (e − ) and protons (H + ), wherein protons (H + ) cross the proton conducting membrane from the anode compartment into the catholyte, and wherein the second member of the redox couple in the lower oxidation state is oxidized back to the first member of the redox couple in the higher oxidation state by metal ion-oxidizing microorganisms in an aerobic oxidation reaction in the presence of oxygen, wherein electrical power is obtained by making electrical connection between a load and the anode and cathode electrodes; and f) liquid circulation mechanism configured to circulate the catholyte such that the second member of the redox couple in the lower oxidation state produced at the cathode and protons (H + ) are transported away from the cathode electrode.