Electrochemical Utilization of CO2 From Coal Power Plants

The conversion of CO2 to value-added products is an attractive approach for reducing the cost of CO2 capture. The successful development of a commercially viable process to convert post-combustion CO2 into formic acid will have a multitude of benefits to the CO2 capture community by partially offsetting the cost of carbon capture from the utility and industrial sectors. The deployment of CO2 utilization technologies will result in two major benefits: 1) reducing the cost of CO2 capture from coal-fired utility units; and 2) production of a valuable product, formic acid, at a lower cost than is currently available. Formic acid is a multipurpose industrial chemical feedstock for formic acid fuel cells, additives in the textile and agricultural sectors, cleaning products, and corrosion inhibitors. The state-of-the-art Kemira process for industrial formic acid production is energy-intensive and requires additional separation and purification steps to produce purified formic acid. Conversely, an electrochemical approach reduces the chemical input for formic acid production, and can be produced directly with electricity supplied via renewable/intermittent power sources. However, conventional electrochemical processes for CO2 reduction to formic acid exhibit selectivity issues where the electro-catalyst typically produces unwanted by-products like hydrogen, carbon monoxide, methanol, and methane that reduces the faradaic efficiency of the CO2 conversion process by up to 50%. To overcome current efficiency difficulties, a process has been developed featuring a catalyst with high selectivity for formic acid production (+90% conversion efficiency). The CAER-Andora process combines an electrochemical cell that features graphite electrodes and an electrochemically facile charge mediator, combined with an immobilized proprietary catalyst. These processes work together to 1) reduce faradaic inefficiencies by producing only formic acid, 2) protect the valuable catalyst from deactivation by overpotentials.