Experimental Investigations of Peridotite-H2O-CO2 Interactions under Hydrothermal Conditions: A Study of Carbon Sequestration and Abiotic Synthesis of Organic Compounds

水热条件下橄榄岩-H2O-CO2相互作用的实验研究：碳封存和有机化合物非生物合成的研究

• 批准号: 1427274
• 负责人: Frieder Klein
• 金额: $ 29.97万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1427274&HistoricalAwards=false
• 关键词: Experimental; Investigations; Peridotite; H2O; CO2

The reaction of some rocks found on Earth's surface with carbon dioxide (CO2) dissolved in surface and subsurface waters can result in mineral reactions that remove CO2 from the fluid. This, in turn, removes CO2 from the atmosphere in a process called carbon sequestration. Under the right conditions, the same reactions can cause the formation of organic compounds in a process called abiotic synthesis which results in the formation of organic compounds from inorganic chemical species. If we better understand processes of carbon sequestration involving natural rock systems, we may be able to devise efficient and effective means for reducing atmospheric CO2 by locking atmospheric carbon up in minerals. A better understanding of how organic compounds form from inorganic materials and interactions with minerals will help us better understand how microbes that live deep in Earth's subsurface are able to survive and thrive in environments where they are isolated from conventional sources of the organic material. This research provides fundamental experimental data and thermodynamic parameters that improve our understanding of how rocks (i.e. peridotites) that are common on the seafloor and also that occur in some places on land react with CO2-charged aqueous fluids to precipitate the mineral serpentine (i.e. a process called serpentinization) and minerals containing carbon (i.e., carbonates). Experiments will also examine how the same reactions reduce carbon from CO2 to form hydrocarbons that can serve as food for microbes living deep inside the Earth in rocks and sediments. Broader impacts of the work include broadening participation of groups under-represented in the sciences by engaging Puerto Rican undergraduates in research and bringing them to the Woods Hole Oceanographic Institution as Woods Hole Summer Student Fellows. Students will remain in residence for 10 to 12 weeks and participate in the experimental work. The effort also includes close interaction between a faculty member at the University of Puerto Rico, Mayaguez and researchers at Woods Hole Oceanographic Institution in Massachusetts. Additional impacts include training of a female PhD student and interaction between the scientists and high school students at the Falmouth Academy near Woods Hole MA. The interaction with the Academy will include lectures and visits to the experimental lab at Woods Hole so students can see, first hand, what it is like to do science and what tools and approaches scientists use.To achieve research goals, laboratory experiments will be run in Dixon bombs at temperatures from 200 to 300 C, 35 MPa, and water-to-rock ratios found in natural seafloor hydrothermal systems. Each experiment will last for several months and involve the reaction of peridotite (lherzolite) and minerals (olivine) with CO2-charged fluids. Experiments have been designed to cause the formation and growth of serpentine and carbonate minerals from starting materials. Changes in fluid composition will be monitored over the duration of the experiments, as will the compositional changes in system solids. Special attention will be paid to the formation of carbonate minerals of various types and the abiotic synthesis of organic compounds in particular CO2, H2, HCOOH, CO, CH3OH, and CH4. Run reactants and products will be characterized and examined by petrographic and spectroscopic techniques. Using these resulting data, correlations will be made between mineral replacement reactions and fluid chemical changes. Additionally, changes in fluid chemistry will be used to determine stable and metastable heterogeneous phase equilibria, reaction pathways, and kinetic rates of both serpentinization and mineral carbonation reactions. Reaction path models will be used for the system Mg-Si-Fe-Al-Ca-Na-K-O-H-C both to help design the experiments and analyze results using thermodynamic and kinetic constraints.

地球表面发现的一些岩石与溶解在地表和地下水中的二氧化碳 (CO2) 发生反应，会导致矿物反应，从而从流体中去除二氧化碳。 这反过来又通过称为碳封存的过程从大气中去除二氧化碳。在适当的条件下，相同的反应可以在称为非生物合成的过程中导致有机化合物的形成，该过程导致无机化学物质形成有机化合物。如果我们更好地了解涉及天然岩石系统的碳封存过程，我们也许能够设计出高效且有效的方法，通过将大气中的碳锁定在矿物质中来减少大气中的二氧化碳。更好地了解有机化合物如何从无机材料形成以及与矿物质的相互作用，将有助于我们更好地了解生活在地球地下深处的微生物如何能够在与传统有机材料来源隔离的环境中生存和繁衍。这项研究提供了基本的实验数据和热力学参数，提高了我们对海底常见岩石（即橄榄岩）以及陆地上某些地方的岩石（即橄榄岩）如何与充有二氧化碳的水性流体发生反应以沉淀矿物蛇纹石（即蛇纹石）的理解。称为蛇纹石化的过程）和含碳矿物（即碳酸盐）。实验还将研究相同的反应如何将二氧化碳中的碳还原成碳氢化合物，这些碳氢化合物可以作为生活在地球深处岩石和沉积物中的微生物的食物。这项工作的更广泛影响包括通过让波多黎各本科生参与研究并将他们带到伍兹霍尔海洋研究所作为伍兹霍尔暑期学生研究员来扩大科学领域代表性不足的群体的参与。 学生将在宿舍停留10至12周并参与实验工作。 这项工作还包括波多黎各大学马亚圭斯分校的教职人员与马萨诸塞州伍兹霍尔海洋研究所的研究人员之间的密切互动。其他影响包括对一名女博士生的培训以及马萨诸塞州伍兹霍尔附近法尔茅斯学院科学家与高中生之间的互动。 与学院的互动将包括讲座和参观伍兹霍尔的实验实验室，以便学生可以第一手了解科学研究是什么样的以及科学家使用什么工具和方法。为了实现研究目标，将进行实验室实验在狄克逊炸弹中，温度为 200 至 300 C，压力为 35 MPa，水石比为天然海底热液系统中的水石比。 每个实验将持续几个月，涉及橄榄岩（二辉橄榄石）和矿物（橄榄石）与充有二氧化碳的流体的反应。 实验的目的是使起始材料形成和生长蛇纹石和碳酸盐矿物。在实验过程中将监测流体成分的变化以及系统固体成分的变化。将特别关注各种碳酸盐矿物的形成以及有机化合物（特别是CO2、H2、HCOOH、CO、CH3OH和CH4）的非生物合成。运行反应物和产物将通过岩相学和光谱技术进行表征和检查。使用这些结果数据，将在矿物替代反应和流体化学变化之间建立关联。此外，流体化学的变化将用于确定稳定和亚稳定的异相平衡、反应途径以及蛇纹石化和矿物碳酸化反应的动力学速率。反应路径模型将用于 Mg-Si-Fe-Al-Ca-Na-K-O-H-C 系统，以帮助设计实验并使用热力学和动力学约束分析结果。