Direct atmospheric cryogenic carbon capture in cold climates

Abstract

Fossil fuel burning and land clearing have significantly increased atmospheric carbon dioxide (CO2) levels from a preindustrial concentration of about 280 ppm to over 420 ppm, leading to a rise in global temperatures and ocean acidity. Although there exist both natural ways to capture carbon, such as trees, oceans, and wetlands, and engineered approaches, such as capturing CO2 at the source of flue gas, even under extremely optimistic scenarios, additional methods to capture carbon directly from the atmosphere are needed. This account provides a critical examination of the concept, as well as a review of pioneering early-stage research pertaining to cryogenic CO2 capture plants designed for deployment in extremely cold environments, such as northern Canada, Siberia, or Antarctica. Based on theoretical analysis, such a plant could desublimate CO2 at an energy cost of around 30 GJ/tonne CO2, which is about an order of magnitude higher than chemical-based approaches. With further research and technological advancements, the cryogenic direct-air capture (DAC) of CO2 could potentially become economically feasible.