Economic and energetic analysis of capturing CO2 from ambient air
Economic and energetic analysis of capturing CO2 from ambient air
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DOI：
10.1073/pnas.1012253108
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发表时间：
2011-12-20
影响因子：
11.1
通讯作者：
Herzog, Howard J.
中科院分区：
文献类型：
--
作者：
House, Kurt Zenz;Baclig, Antonio C.;Herzog, Howard J.
在工业过程中从大气中捕获二氧化碳（“空气捕获”）已被提议作为稳定全球CO2浓度的一个备选方案。已发布的分析表明，这些空气捕获系统每吨二氧化碳的成本可能为数百美元，使其与可再生能源、核电以及大型二氧化碳排放点源的二氧化碳捕获和储存等主流二氧化碳减排方案相比具有成本竞争力。我们调查了商业分离系统以及痕量气体去除系统的热力学效率，以更好地理解和约束这些空气捕获系统的能量需求和成本。我们对商业过程的经验分析表明，从空气中捕获CO2的能量和财务成本可能被低估了。具体而言，我们对现有气体分离系统的分析表明，除非空气捕获显著优于这些系统，否则每摩尔CO2可能需要超过400 kJ的功，需要由CO2中性电源供电，以便为CO2负。根据已建成的大型痕量气体去除系统的经验，我们估计空气捕获系统的总系统成本将在每吨CO2 1,000美元左右。
Capturing carbon dioxide from the atmosphere ("air capture") in an industrial process has been proposed as an option for stabilizing global CO2 concentrations. Published analyses suggest these air capture systems may cost a few hundred dollars per tonne of CO2, making it cost competitive with mainstream CO2 mitigation options like renewable energy, nuclear power, and carbon dioxide capture and storage from large CO2 emitting point sources. We investigate the thermodynamic efficiencies of commercial separation systems as well as trace gas removal systems to better understand and constrain the energy requirements and costs of these air capture systems. Our empirical analyses of operating commercial processes suggest that the energetic and financial costs of capturing CO2 from the air are likely to have been underestimated. Specifically, our analysis of existing gas separation systems suggests that, unless air capture significantly outperforms these systems, it is likely to require more than 400 kJ of work per mole of CO2, requiring it to be powered by CO2-neutral power sources in order to be CO2 negative. We estimate that total system costs of an air capture system will be on the order of $1,000 per tonne of CO2, based on experience with as-built large-scale trace gas removal systems.