Driver Justin G, Bernard Ellina, Patrizio Piera, Fennell Paul S, Scrivener Karen, Myers Rupert J
Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
Proc Natl Acad Sci U S A. 2024 Jul 16;121(29):e2313475121. doi: 10.1073/pnas.2313475121. Epub 2024 Jul 8.
CO mineralization products are often heralded as having outstanding potentials to reduce CO-eq. emissions. However, these claims are generally undermined by incomplete consideration of the life cycle climate change impacts, material properties, supply and demand constraints, and economic viability of CO mineralization products. We investigate these factors in detail for ten concrete-related CO mineralization products to quantify their individual and global CO-eq. emissions reduction potentials. Our results show that in 2020, 3.9 Gt of carbonatable solid materials were generated globally, with the dominant material being end-of-life cement paste in concrete and mortar (1.4 Gt y). All ten of the CO mineralization technologies investigated here reduce life cycle CO-eq. emissions when used to substitute comparable conventional products. In 2020, the global CO-eq. emissions reduction potential of economically competitive CO mineralization technologies was 0.39 Gt CO-eq., i.e., 15% of that from cement production. This level of CO-eq. emissions reduction is limited by the supply of end-of-life cement paste. The results also show that it is 2 to 5 times cheaper to reduce CO-eq. emissions by producing cement from carbonated end-of-life cement paste than carbon capture and storage (CCS), demonstrating its superior decarbonization potential. On the other hand, it is currently much more expensive to reduce CO-eq. emissions using some CO mineralization technologies, like carbonated normal weight aggregate production, than CCS. Technologies and policies that increase recovery of end-of-life cement paste from aged infrastructure are key to unlocking the potential of CO mineralization in reducing the CO-eq. footprint of concrete materials.
二氧化碳矿化产品常常被誉为具有降低二氧化碳当量排放的巨大潜力。然而，这些说法通常因对生命周期气候变化影响、材料特性、供需限制以及二氧化碳矿化产品的经济可行性考虑不全面而受到削弱。我们详细研究了十种与混凝土相关的二氧化碳矿化产品的这些因素，以量化它们各自以及全球的二氧化碳当量减排潜力。我们的结果表明，2020年全球产生了39亿吨可碳酸化固体材料，其中主要材料是混凝土和砂浆中的废弃水泥浆（14亿吨/年）。这里研究的所有十种二氧化碳矿化技术在用于替代可比的传统产品时，都会降低生命周期的二氧化碳当量排放。2020年，经济上具有竞争力的二氧化碳矿化技术的全球二氧化碳当量减排潜力为0.39亿吨二氧化碳当量，即占水泥生产减排量的15%。这种程度的二氧化碳当量减排受到废弃水泥浆供应的限制。结果还表明，用碳酸化的废弃水泥浆生产水泥来降低二氧化碳当量排放比碳捕获与封存（CCS）便宜2至5倍，这表明其具有卓越的脱碳潜力。另一方面，目前使用一些二氧化碳矿化技术（如碳酸化普通重量骨料生产）来降低二氧化碳当量排放比CCS要昂贵得多。提高从老化基础设施中回收废弃水泥浆的技术和政策是释放二氧化碳矿化在减少混凝土材料二氧化碳当量足迹方面潜力的关键。
