Integrating climate and physical constraints into assessments of net capture from direct air capture facilities

Abstract

Limiting climate change to targets enshrined in the Paris Agreement will require both deep decarbonization of the energy system and the deployment of carbon dioxide removal at potentially large scale (gigatons of annual removal). Nations are pursuing direct air capture to compensate for inertia in the expansion of low-carbon energy systems, decarbonize hard-to-abate sectors, and address legacy emissions. Global assessments of this technology have failed to integrate factors that affect net capture and removal cost, including ambient conditions like temperature and humidity, as well as emission factors of electricity and natural gas systems. We present an integrated assessment of the global deployment potential of this technology. Employing a chemical process model, climate data, grid emission factors, and fugitive methane emission factors, we predict critical performance metrics, including carbon dioxide capture rates, and water-, energy-, and emissions-intensity of capture. Our results support investors and policy makers as they site facilities and develop credible policy instruments to support expansion.