Joule
ArticleA comparative energy and costs assessment and optimization for direct air capture technologies
Context & scale
Artificial removal of CO2 from the atmosphere will be pivotal for the realization of CO2-net-zero plans and policies. Among the few available solutions, the direct extraction from air—or direct air capture (DAC)—features the highest removal potential. Although energy and economic expenditure are high, DAC is still in its infancy, and a large potential exists for its optimization. To scale up the production, the different processes should be consistently evaluated, their design and operation optimized, and the needs for further development identified. Surprisingly, this is missing in the literature. In this study, we discuss the optimal process design and performance for the main DAC technologies, starting from publicly available unit designs and data and by using advanced simulation tools. Moreover, we identify the open challenges that need addressing and compute the CO2 capture cost as a function of energy and equipment costs, showing the combinations that would allow for cheaper DAC units.