Abstract: The present invention disclosed herein is directed to nitric acid regeneration fuel cell systems that comprise: an anode; a cathode confronting and spaced apart from the anode; an anolyte flowstream configured to flowingly contact the anode, wherein the anolyte flowstream includes a fuel, preferably methanol, for reacting at the anode; a catholyte flowstream configured to flowingly contact the cathode, wherein the catholyte flowstream includes nitric acid for reacting at the cathode to thereby yield cathode reaction products that include nitric oxide and water in a catholyte effluent flowstream; and a hydrogen peroxide flowstream configured to contact and react hydrogen peroxide with the nitric oxide of the catholyte effluent flowstream at a hydrogen peroxide oxidation zone to thereby yield a regenerated nitric acid flowstream. The regenerated nitric acid flowstream is preferably reused in the catholyte flowstream.

Abstract: The invention disclosed herein relates to fuel cell electrode pair assemblies, not having interposing proton exchange membranes, configured to receive and react with liquid anolyte and liquid catholyte microfluidic flowstreams. In one embodiment, the present invention is directed to a fuel cell electrode pair assembly, not having an interposing proton exchange membrane, configured to receive and react with a liquid microfluidic anolyte flowstream (e.g., laminarly flowing methanol solution) and a liquid microfluidic catholyte flowstream (e.g., laminarly flowing nitric acid solution), wherein the fuel cell electrode pair assembly comprises: a porous flow-through anode; a porous flow-by cathode confronting and spaced apart from the anode; and a central plenum interposed between and connected to the anode and the cathode.

Abstract: The invention disclosed herein relates to fuel cell electrode pair assemblies, not having interposing proton exchange membranes, configured to receive and react with liquid anolyte and liquid catholyte microfluidic flowstreams. In one embodiment, the present invention is directed to a fuel cell electrode pair assembly, not having an interposing proton exchange membrane, configured to receive and react with a liquid microfluidic anolyte flowstream (e.g., laminarly flowing methanol solution) and a liquid microfluidic catholyte flowstream (e.g., laminarly flowing nitric acid solution), wherein the fuel cell electrode pair assembly comprises: a porous flow-through anode; a porous flow-by cathode confronting and spaced apart from the anode; and a central plenum interposed between and connected to the anode and the cathode.

Abstract: The present invention disclosed herein is directed to nitric acid regeneration fuel cell systems that comprise: an anode; a cathode confronting and spaced apart from the anode; an anolyte flowstream configured to flowingly contact the anode, wherein the anolyte flowstream includes a fuel, preferably methanol, for reacting at the anode; a catholyte flowstream configured to flowingly contact the cathode, wherein the catholyte flowstream includes nitric acid for reacting at the cathode to thereby yield cathode reaction products that include nitric oxide and water in a catholyte effluent flowstream; and a hydrogen peroxide flowstream configured to contact and react hydrogen peroxide with the nitric oxide of the catholyte effluent flowstream at a hydrogen peroxide oxidation zone to thereby yield a regenerated nitric acid flowstream. The regenerated nitric acid flowstream is preferably reused in the catholyte flowstream.