The global energy demand has continuously been growing over past several decades, expediting the consumption of natural resources. This has not only endangered the conventional fossil fuel based energy supply chain but also elevated emission of the green house gases, resulting in a severe risk of climate change and other related problems. In order to cope with these issues, adoption of renewable energy based technologies with zero/low emissions and mitigation of carbon dioxide (CO2) by carbon dioxide capture and utilization (CCU) strategy has actively been promoted.
Carbon dioxide can serve as a feedstock for producing useful organic and inorganic substances such as methanol, formic acid, carbonates and bicarbonates etc., through biological, thermal, chemical and electrochemical methods. CO2 can be converted into sodium carbonate and bicarbonate by an electrochemical method using abundantly available NaCl salt. This process involves electrolysis of aqueous solution of NaCl (brine) to produce alkali (NaOH), followed by its reaction with CO2 to generate sodium carbonate/bicarbonate. The production of NaOH from brine electrolysis is an energy driven process and requires a certain amount of input energy. While conversion of CO2 into useful products appears to be an exciting mitigation strategy, there are certain technical barriers that have to be overcome for making this process energy efficient.
This presentation will encompass our efforts for developing a compact continuous-flow electrochemical cell for brine electrolysis and sequestration of carbon dioxide. The effects of flow field designs, cell configurations, electrode structures and operating conditions on the cell performance and stability will be discussed. I will briefly present our activities for successfully achieving a 75% reduction of anode catalyst loadings through structural modifications, simplification of cell configuration as well as effects of brine concentration and thickness of ion-exchange membranes. A comparison of two different cell configurations on cell performance and stability will also be included.