Geochemical reactions of Na-montmorillonite in dissolved scCO2 in relevance of modeling caprock behavior in CO2 geological storage

Authors

  • Zsuzsanna Szabó
    Affiliation
    Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Institute of Geography and Earth Sciences, Faculty of Science, Eötvös Loránd University, H-1117 Budapest, Pázmány Péter sétány 1/C, Hungary; MTA Premium Postdoctoral Research Program, MTA Office for Research Groups Attached to Universities and Other Institutions, Hungarian Academy of Sciences, H-1051 Budapest, Nádor u. 7., Hungary
  • Csaba Hegyfalvi
    Affiliation
    Department of Chemical and Environmental Process Engineering, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1111 Budapest, Műegyetem rakpart 3., Hungary
  • Ágnes Freiler-Nagy
    Affiliation
    CEMKUT Research & Development for the Cement Industry Ltd., H-1034 Budapest, Bécsi út 122-124., Hungary
  • Beatrix Udvardi
    Affiliation
    KTI Institute for Transport Sciences Non-profit Ltd., H-1119 Budapest, Than Károly u. 3-5., Hungary
  • Péter Kónya
    Affiliation
    Department of Hydrogeology and Geochemistry, Mining and Geological Survey of Hungary, H-1143 Budapest, Stefánia út 14., Hungary
  • Csilla Király
    Affiliation
    Geographical Institute, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, H-1112 Budapest, Budaörsi út 45., Hungary
  • Edit Székely
    Affiliation
    Department of Chemical and Environmental Process Engineering, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1111 Budapest, Műegyetem rakpart 3., Hungary
  • György Falus
    Affiliation
    Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Institute of Geography and Earth Sciences, Faculty of Science, Eötvös Loránd University, H-1117 Budapest, Pázmány Péter sétány 1/C, Hungary
https://doi.org/10.3311/PPch.12850

Abstract

One of the challenges of the present century is to limit the greenhouse gas emissions for the mitigation of climate change which is possible for example by a transitional technology, CO2 geological storage. Clay minerals are considered to be responsible for the low permeability and sealing capacity of caprocks sealing off stored CO2. However, their reactions are not well understood for complex simulations. This work aims to create a kinetic geochemical model of Na-montmorillonite standard SWy-2 supported by solution and mineral composition results from batch experiments. Such experimentally validated numerical models are scarce. Four 70-hours experiments have been carried out at atmospheric conditions, and with CO2 supercritical phase at 100 bar and 80 °C. Solution samples have been taken during and after experiments and their compositions were measured by ICP-OES. The treated solid phase has been analyzed by XRD and ATR-FTIR and compared to in-parallel measured references (dried SWy-2). Kinetic geochemical modelling of the experimental conditions has been performed by software PHREEQC. Experiments and models show fast reactions under the studied conditions and increased reactivity in presence of scCO2. Solution composition results cannot be described by the change of the uncertain reactive surface area of mineral phases. By considering the clay standard’s cation exchange capacity divided proportionally among interlayer cations of Na-montmorillonite, the measured variation can be described on an order of magnitude level. It is furthermore indicated that not only the interlayer cations take part in this process but a minor proportion of other, structural ions as well, differently in the reference and scCO2 environments.

Keywords:

CO2 geological storage, Na-montmorillonite, laboratory batch experiments, kinetic geochemical modeling, PHREEQC

Citation data from Crossref and Scopus

Published Online

2019-03-18

How to Cite

Szabó, Z., Hegyfalvi, C., Freiler-Nagy, Ágnes, Udvardi, B., Kónya, P., Király, C. “Geochemical reactions of Na-montmorillonite in dissolved scCO2 in relevance of modeling caprock behavior in CO2 geological storage”, Periodica Polytechnica Chemical Engineering, 63(2), pp. 318–327, 2019. https://doi.org/10.3311/PPch.12850

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