Nitric acid regeneration fuel cell systems

摘要

Methods and systems for regenerating a fuel cell are disclosed, comprising sparging a catholyte liquid with a gaseous oxygen-containing flow stream. In addition, the gaseous byproducts in the catholyte can be collected and then converted to liquid forms for easy disposal. In some embodiments, the regeneration process comprises intermittently regenerating an oxidant flow stream, for example, based on detected conditions. In some embodiments, the regeneration process comprises switching between different modes of oxidant regeneration, for example, based on detected conditions.

主权项

1. A method for regenerating a fuel cell, the method comprising
flowing an anolyte flow stream to an anode,
wherein the anolyte flow stream comprises a fuel for reacting at the anode; flowing a catholyte flow stream to a cathode,
wherein the catholyte flow stream comprises nitric acid for reacting at the cathode to yield gaseous nitrogen oxide in a catholyte effluent flow stream; flowing an oxygen-containing flow stream to the catholyte effluent flow stream,
wherein the oxygen-containing flow stream bubbles through the catholyte effluent flow stream to react with the gaseous nitrogen oxide of the catholyte effluent flow stream; collecting a portion of the gaseous nitrogen oxide in the catholyte effluent flow stream; delivering the portion of the gaseous nitrogen oxide to a liquid oxidant reservoir,
wherein the liquid oxidant reservoir is configured to react with the portion of the gaseous nitrogen oxide.