CO2 sequestration in peridotites - experimental carbonation of olivine and pyroxene

碳酸化水溶液与超镁质岩层反应生成稳定的碳酸盐矿物是长期封存二氧化碳最有前途的方案之一。由于橄榄石矿物橄榄石和正辉石中镁和铁含量高，透辉石中钙含量高，因此橄榄岩被建议作为这些方案的起始材料。然而，反应条件的变化极大地改变了橄榄岩矿物反应沉淀的相，这对碳酸化过程的进展具有重要影响。虽然大多数碳酸化研究都集中在橄榄石碳酸化反应上，但对辉石在碳酸化过程中的作用知之甚少。因此，本项目的目的是深入研究橄榄石和辉石在不同条件下的替代及其对次生相形成的影响。将使用广泛的分析技术对这些反应进行原位和非原位研究，以帮助限制碳封存方案的地球化学模型。

Reacting carbonated aqueous solutions with ultramafic rock formations to produce stable carbonate minerals is one of the most promising schemes for the long-term sequestration of carbon dioxide. Peridotite has been proposed as a starting material for these schemes due to its high magnesium and iron content in the minerals olivine and orthopyroxene, as well as calcium content in diopside. However, changes in the reaction conditions dramatically alter the phases precipitated from the reactions of the peridotite minerals, and this has important consequences for the progression of the carbonation process. Although most carbonation studies have focused on olivine carbonation reactions, little is known about the role of pyroxene on the carbonation process. Therefore, the aim of this project is to conduct an in-depth study of olivine and pyroxene replacement at different conditions and the effect on the formation of secondary phases. The reactions will be studied both in-situ and ex-situ using a wide range of analytical techniques to help constrain the geochemical models of carbon sequestration schemes.