Lammers Laura N, Duan Yanghua, Anaya Luis, Koishi Ayumi, Lopez Romario, Delima Roxanna, Jassby David, Sedlak David L
Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720, United States.
Travertine Technologies, Inc., Boulder, Colorado 80301, United States.
ACS Sustain Chem Eng. 2023 Mar 13;11(12):4800-4812. doi: 10.1021/acssuschemeng.2c07441. eCollection 2023 Mar 27.
Several billion metric tons per year of durable carbon dioxide removal (CDR) will be needed by mid-century to prevent catastrophic climate warming, and many new approaches must be rapidly scaled to ensure this target is met. Geologically permanent sequestration of carbon dioxide (CO) in carbonate minerals-carbon mineralization-requires two moles of alkalinity and one mole of a CO-reactive metal such as calcium or magnesium per mole of CO captured. Chemical weathering of geological materials can supply both ingredients, but weathering reactions must be accelerated to achieve targets for durable CDR. Here, a scalable CDR and mineralization process is reported in which water electrolysis is used to produce sulfuric acid for accelerated weathering, while a base is used to permanently sequester CO from air into carbonate minerals. The process can be integrated into existing extractive processes by reacting produced sulfuric acid with critical element feedstocks that neutralize acidity (e.g., rock phosphorus or ultramafic rock mine tailings), with calcium- and magnesium-bearing sulfate wastes electrolytically upcycled. The highest reported efficiency of electrolytic sulfuric acid production is achieved by maintaining catholyte feed conditions that minimize Faradaic losses by hydroxide permeation of the membrane-separated electrochemical cell. The industrial implementation of this process provides a pathway to gigaton-scale CO removal and sequestration during the production of critical elements needed for decarbonizing global energy infrastructure and feeding the world.
到本世纪中叶，每年将需要数十亿公吨的持久性二氧化碳去除（CDR）以防止灾难性的气候变暖，并且必须迅速扩大许多新方法的规模以确保实现这一目标。将二氧化碳（CO）地质永久性封存于碳酸盐矿物中——碳矿化——每捕获一摩尔CO需要两摩尔碱度和一摩尔诸如钙或镁的CO反应性金属。地质材料的化学风化可以提供这两种成分，但必须加速风化反应以实现持久性CDR的目标。在此，报道了一种可扩展的CDR和矿化过程，其中利用水电解生产硫酸以加速风化，同时使用碱将空气中的CO永久性封存到碳酸盐矿物中。该过程可以通过使产生的硫酸与中和酸度的关键元素原料（例如磷矿石或超镁铁岩矿山尾矿）反应而整合到现有的提取过程中，含钙和镁的硫酸废物通过电解实现升级回收。通过维持阴极电解液进料条件，使膜分离电化学电池中氢氧化物渗透导致的法拉第损失最小化，实现了报道的最高电解硫酸生产效率。该过程的工业实施为在全球能源基础设施脱碳和养活世界所需的关键元素生产过程中实现千兆吨规模的CO去除和封存提供了一条途径。
