Dissolution kinetics of selected natural minerals relevant to potential CO₂-injection sites − Part 1: A review

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• 作者：Astrid Holzheid ^{holzheid@min.uni-kiel.de}
• 关键词：Dissolution ; Kinetics ; Carbonates ; Feldspar group minerals ; CO2&ndash ; sequestration
• 刊名：Chemie der Erde - Geochemistry
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：76
• 期：4
• 页码：621-641
• 全文大小：5336 K
• 卷排序：76

文摘

This publication provides a literature review on experimental studies of dissolution kinetics of mainly carbonates and feldspar group minerals, i.e. most common minerals at potential CO2-injection and/or storage sites. Geochemical interaction processes between injected CO2 and coexisting phases, namely reservoir and cap rock minerals and formation fluids close to the CO2-injection site can be simulated by flow-through or mixed flow reactors, while processes far from the injection site and long-term processes after termination actual CO2-injection can be mimicked by batch reactors. At sufficient small stirring rates or fluid flow rates as well as low solute concentrations flow-through reactors are also able to simulate processes far from the injection site. The experimental parameter temperature not only intensifies the dissolution process, the dominant dissolution mechanisms are also influenced by temperature. The dissolution mechanisms change from incongruent and surface controlled mechanisms at lower temperatures to congruent and transport controlled mechanisms at higher temperatures. The CO2 partial pressure has only a second order influence on dissolution behavior compared to the influence of pH-value and ionic strength of the CO2-bearing brine. Minerals exposed to CO2-bearing brines at elevated temperatures and pressures are subject of alteration, leading to severe changes of reactive surfaces and potential precipitation of secondary minerals.Computational simulations of mineral reactions at potential CO2 storage sites have therefore to include not only the time-resolved changes of dissolution behavior and hence kinetics of mineral dissolution, but also the influence of secondary minerals on the interaction of the minerals with CO2-enriched brines.