Mechanisms and applications of gas-driven mineral weathering: Implications for the geologic carbon cycle and engineered carbon storage

气体驱动矿物风化的机制和应用：对地质碳循环和工程碳储存的影响

• 批准号: RGPIN-2019-05324
• 负责人: Harrison, Anna
• 金额: $ 2.55万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715463
• 关键词: Mechanisms; applications; gas; driven; mineral

The CO2-driven weathering of silicate minerals removes CO2 from the atmosphere as well as releasing nutrients essential for plant and microbial growth, whereas O2-driven sulphide weathering can release CO2. These gas-driven mineral weathering processes, followed by the precipitation of carbonate minerals in the oceans, regulate atmospheric CO2 concentrations and global climate over geologic time. Moreover, the engineering of these natural processes to accelerate CO2 storage is a promising strategy to help mitigate greenhouse gas-fuelled climate change. Although the global-scale implications of gas-driven mineral weathering reactions have been recognized, the mechanisms that control their reaction in water-unsaturated Earth materials remains poorly understood. The proposed research aims to elucidate the physical and chemical controls on gas-driven mineral weathering, and will comprise three main themes: 1) the impact of CO2 concentration on mineral weathering, 2) the role of water in mineral weathering reactions, and 3) designing engineered CO2 storage strategies. An experimental approach will be taken to determine mechanisms of gas-driven mineral weathering reactions, and reactive transport and geochemical modelling will be used to extrapolate experimental results to larger spatial and temporal scales. Fundamental mechanisms of gas-driven mineral weathering reactions revealed through Themes 1 and 2 will inform the design of engineered CO2 storage strategies that exploit natural weathering processes to capture and store anthropogenic CO2. Experiments will test strategies to optimize CO2 storage during accelerated weathering of natural rock as well as waste products from the mining industry. Fine grained waste products, known as tailings, from certain mine sites have a significant but untapped potential to capture and store atmospheric CO2. Reactive transport modelling will be used to tailor CO2 sequestration strategies to particular sites based on characteristics such as climate and chemical properties of the tailings or rock. Together, these studies will provide insight into the mechanisms that have helped moderate Earth's climate through geologic time, permit better assessment of the response of mineral weathering reactions to changes in water availability due to climate change, and contribute to the design of climate change mitigation strategies. Tangible benefits will be achieved through the production of reactive transport models that can be used by academic and industrial users to simulate the consequence of environmental change on weathering reactions, and design CO2 storage strategies. Such CO2 storage strategies will help Canada to meet ambitious greenhouse gas reduction targets. During this research, highly qualified personnel will be trained in analytical, experimental, and modelling techniques, and gain transferable skills. This skill set can be applied to environmental policy, environmental consulting, or continued academic research.

硅酸盐矿物的CO2驱动的风化作用从大气中去除CO2，并释放植物和微生物生长所必需的营养物质，而O2驱动的硫化物风化作用可以释放CO2。这些气体驱动的矿物风化过程，随后是海洋中碳酸盐矿物的沉淀，在地质时期调节大气中的CO2浓度和全球气候。此外，工程这些自然过程，以加速二氧化碳的储存是一个有前途的战略，以帮助减轻温室气体燃料的气候变化。虽然气体驱动的矿物风化反应的全球范围内的影响已被认识到，控制其在水不饱和地球材料的反应的机制仍然知之甚少。拟议的研究旨在阐明气体驱动矿物风化的物理和化学控制，将包括三个主题：1）CO2浓度对矿物风化的影响，2）水在矿物风化反应中的作用，以及3）设计工程CO2储存策略。将采取实验方法来确定气体驱动的矿物风化反应的机制，并将使用反应性迁移和地球化学建模来将实验结果外推到更大的空间和时间尺度。通过主题1和2揭示的气体驱动的矿物风化反应的基本机制将为利用自然风化过程捕获和储存人为CO2的工程CO2储存策略的设计提供信息。实验将测试在天然岩石加速风化过程中优化二氧化碳储存的策略，以及采矿业的废物。来自某些矿场的细粒废物产品（称为尾矿）具有捕获和储存大气CO2的巨大但尚未开发的潜力。将使用反应性迁移模型，根据气候和尾矿或岩石的化学性质等特点，针对具体地点制定二氧化碳固存战略。这些研究将共同深入了解在地质时期帮助调节地球气候的机制，更好地评估矿物风化反应对气候变化引起的水资源可用性变化的反应，并有助于设计气候变化缓解策略。气候变化的好处将通过生产反应性运输模型来实现，这些模型可供学术和工业用户用于模拟环境变化对风化反应的影响，并设计CO2储存策略。这种二氧化碳储存战略将有助于加拿大实现雄心勃勃的温室气体减排目标。在这项研究中，高素质的人员将接受分析，实验和建模技术的培训，并获得可转移的技能。该技能可应用于环境政策，环境咨询或继续学术研究。