A significant challenge in managing air quality in closed environments such as naval submarines is mitigating carbon dioxide concentration, which can accumulate to levels toxic to humans through normal respiration if not actively removed. The Navy currently uses liquid and solid amine based chemistries to capture CO2 from cabin air, which require high maintenance and routine regeneration. These systems also are energy intensive and typically can only remove CO2 to a threshold value which is below the toxicity limit but still higher than desired. Proton OnSite proposes an electrochemical method of separating CO2 from cabin air based on ion exchange membranes. The proposed solution would improve energy consumption, reduce operating complexity and footprint, and provide full CO2 removal capacity, with simplified designs that eliminate mechanical and electrical failure mechanisms. Protons capabilities in electrode fabrication, membrane-based electrochemical cells and stacks, electrochemical pumping, and gas-liquid balance of plant design will enable these advancements and lead to a commercially viable product for the Navy and other applications.
Benefit: Capture of very low levels of carbon dioxide from the air is a key challenge in reduction of global CO2 levels. While many research groups are working on conversion of CO2 to useful chemicals, the problem of concentrating the CO2 from less than 0.1% levels in the air in order to effectively feed a chemical reactor has not been adequately addressed. At the same time, there is a need for CO2 removal or capture from higher concentration mixtures, such as flue gas, soured natural gas, purification of hydrogen from natural gas reforming, and biogas. The proposed technology is the only known solution that can capture carbon dioxide from a wide range of gas mixtures, from less than 0.1% CO2 to greater than 50% CO2.
Keywords: ion exchange membrane, ion exchange membrane, carbon capture, carbon dioxide, Air Purification, electrochemical separation
