Electrochemical compressor for carbon dioxide.

Carbon dioxide is a natural refrigerant with ultra-low global warming potential. It can replace hydrofluorocarbon working fluids which will be globally phased down by 80% by 2050. Moreover, the mechanical compressor in the refrigeration system has a low isentropic efficiency of 65% so there is much room for efficiency improvement. Whereas, the electrochemical compression can approach isothermal compression by novel compressor design with microchannel heat exchangers embedded so that its Nernst compressor efficiency can be greater than 90%ideally. Our recent works demonstrated that natural refrigerants such as carbon dioxide can be electrochemically compressed without using any moving parts and lubrication oil. Electrochemical compression of carbon dioxide with oxygen as a carrier gas can reach a compression ratio of 6.12. The electrochemical compressor can be the key technology to reduce greenhouse gas emissions by using carbon dioxide as working fluid in vapor compression refrigeration systems.