air conditioner, code tester, solid-state, cyclic, coefficient of degradation
The fundamental mechanisms behind electrochemical compression have long been understood. However, only now is the electrochemical compressor coming to fruition. The electrochemical compressor offers several key advantages over the traditional mechanical compressor. Its lack of moving parts eliminates energy losses due to friction and reduces noise. Electrochemical compression of hydrogen has already been realized at scale, but its usefulness is generally limited to fuel cell applications. Additionally, electrochemical compression has been performed with ammonia, but its toxicity limits its practicality. A carbon dioxide (CO2) compressor, however, would have potential applications in refrigeration systems that utilize CO2 as an environmentally-friendly refrigerant as well as in carbon capture. A major obstacle in electrochemical CO2 compression lies in the design of the gas distribution and collection channels, which supply to and collect gases from anion exchange membrane surface. The unique design challenge of the gas channel design in the electrochemical compressor is because the mass transfer of CO2 occurs throughout the membrane area, rather than at one specific point. At the same time, the membrane requires mechanical support so that is does not rupture under the pressure developed in the compression cell. Therefore, the gas supply and collection plates are designed with built-in flow channels. Here, we present a method for improving the gas channels using computational fluid dynamics to analyze the distribution of gas for different channel geometries. Several potential designs, including traditional fuel cell configurations as well as nature inspired geometries, were evaluated to determine which design is most effective for the CO2 compressor application. We conducted these analyses assuming baseline performance data determined empirically from previous CO2 compression experiments and the known material properties of the anion exchange membrane. The electrochemical CO2 compressor’s significant advantages show great promise for applications in the HVACR industry if these challenges are addressed.