Department of Chemical Engineering, Worcester Polytechnic Institute, Goddard Hall, 100 Institute Road, Worcester, Massachusetts 01609, United States.
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
Environ Sci Technol. 2020 Jun 16;54(12):7542-7551. doi: 10.1021/acs.est.0c00476. Epub 2020 Jun 2.
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/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 for costs ≤$300/tCO, net delivered with an opportunity to scale to 19 MtCO/yr. These scenarios use thermal energy from geothermal and nuclear power plants to produce steam and transport the purified CO via trucks to the nearest opportunity for direct use or subsurface permanent storage. Although some utilization pathways result in the re-emission of CO 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 45Q was applied for qualifying facilities (i.e., producing ≥100 ktCO/yr).
负排放技术将在防止 2100 年升温 2°C 方面发挥重要作用。未来十年对于技术创新和部署至关重要,以实现本世纪中叶每年去除 10-20 亿吨二氧化碳的目标。直接空气捕集(DAC)有望在碳去除方面发挥关键作用,但在部署方面仍进展缓慢,主要是因为成本高。本研究通过利用低温热能、美国最近的政策驱动因素以及美国境内合理的区域终端用途机会,为 DAC 成本降低制定了路线图。具体而言,确定了两种方案,可使压缩高纯 CO 的生产成本降至≤300 美元/吨二氧化碳,净交付,并有可能扩展到每年 1900 万吨二氧化碳。这些方案利用地热能和核能发电厂的热能产生蒸汽,并通过卡车将净化后的 CO 输送到最近的直接使用或地下永久储存机会。尽管一些利用途径会导致 CO 的重新排放,不能被视为真正的碳去除,但它们将为本世纪中叶大规模部署 DAC 工厂提供经济激励。此外,应用了联邦税收抵免 45Q 来为合格设施(即每年生产≥100 千吨二氧化碳)提供资格。