Cost Analysis of Direct Air Capture and Sequestration Coupled to Low-Carbon Thermal Energy in the United States

摘要

Negative emissions technologies will play an important role in preventing 2 °C warming by 2100. The next decade is critical for technological innovation and deployment to meet mid-century carbon removal goals of 10-20 GtCO_2/yr. Direct air capture (DAC) is positioned to play a critical role in carbon removal, yet remains under paced in deployment efforts, mainly because of high costs. This study outlines a roadmap for DAC cost reductions through the exploitation of low-temperature heat, recent U.S. policy drivers, and logical, regional end-use opportunities in the United States. Specifically, two scenarios are identified that allow for the production of compressed high-purity CO_2 for costs ≤$300/tCO_2, net delivered with an opportunity to scale to 19 MtCO_2/yr. These scenarios use thermal energy from geothermal and nuclear power plants to produce steam and transport the purified CO_2 via trucks to the nearest opportunity for direct use or subsurface permanent storage. Although some utilization pathways result in the re-emission of CO_2 and cannot be considered true carbon removal, they would provide economic incentive to deploying DAC plants at scale by mid-century. In addition, the federal tax credit 45Qwas applied for qualifying facilities (i.e., producing ≥100 ktCO_2/yr).