Toward economical application of carbon capture and utilization technology with near-zero carbon emission.

Carbon capture and utilization technology has been studied for its practical ability to reduce CO emissions and enable economical chemical production. The main challenge of this technology is that a large amount of thermal energy must be provided to supply high-purity CO and purify the product. Herein, we propose a new concept called reaction swing absorption, which produces synthesis gas (syngas) with net-zero CO emission through direct electrochemical CO reduction in a newly proposed amine solution, triethylamine. Experimental investigations show high CO absorption rates (>84%) of triethylamine from low CO concentrated flue gas. In addition, the CO Faradaic efficiency in a triethylamine supplied membrane electrode assembly electrolyzer is approximately 30% (@-200 mA cm), twice higher than those in conventional alkanolamine solvents. Based on the experimental results and rigorous process modeling, we reveal that reaction swing absorption produces high pressure syngas at a reasonable cost with negligible CO emissions. This system provides a fundamental solution for the CO crossover and low system stability of electrochemical CO reduction.