2014; 47(4): 421-430

Published online August 31, 2014

© THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY

Experimental Study on the Geochemical and Mineralogical Alterations in a Supercritical CO2-Groundwater-Zeolite Sample Reaction System

Eundoo Park1, Sookyun Wang1* and Minhee Lee2

1Department of Energy Resources Engineering, Pukyong National University, Busan 608-737, Republic of Korea
2Department of Earth Environmental Sciences, Pukyong National University, Busan 608-737, Republic of Korea

Received: April 11, 2014; Revised: June 10, 2014; Accepted: June 19, 2014

Abstract

In this study, a series of autoclave experiments were conducted in order to investigate the geochemical and mineralogical effects of carbon dioxide on deep subsurface environments. High pressure and temperature conditions of 50°C and 100 bar, which are representative environments for geological CO2 sequestration, were created in stainless- steel autoclaves for simulating the interactions in the scCO2-groundwater-mineral reaction system. Zeolite, a widespread mineral in Pohang Basin where many researches have been focused as a candidate for geological CO2 sequestration, and groundwater sampled from an 800 m depth aquifer were applied in the experiments. Geochemical and mineralogical alterations after 30 days of scCO2-groundwater-zeolite sample reactions were quantitatively examined by XRD, XRF, and ICP-OES investigations. The results suggested that dissolution of zeolite sample was enhanced under the acidic condition induced by dissolution of scCO2. As the cation concentrations released from zeolite sample increase, H+ in groundwater was consumed and pH increases up to 10.35 after 10 days of reaction. While cation concentrations showed increasing trends in groundwater due to dissolution of the zeolite sample, Si concentrations decreased due to precipitation of amorphous silicate, and Ca concentrations decreased due to cation exchange and re-precipitation of calcite. Through the reaction experiments, it was observed that introduction of CO2 could make alterations in dissolution characteristics of minerals, chemical compositions and properties of groundwater, and mineral compositions of aquifer materials. Results also showed that geochemical reactions such as cation exchange or dissolution/precipitation of minerals could play an important role to affect physical and chemical characteristics of geologic formations and groundwater.

Keywords carbon dioxide, zeolite, high pressure and temperature, geochemical reaction, dissolution

Article

2014; 47(4): 421-430

Published online August 31, 2014

Copyright © THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY.

Experimental Study on the Geochemical and Mineralogical Alterations in a Supercritical CO2-Groundwater-Zeolite Sample Reaction System

Eundoo Park1, Sookyun Wang1* and Minhee Lee2

1Department of Energy Resources Engineering, Pukyong National University, Busan 608-737, Republic of Korea
2Department of Earth Environmental Sciences, Pukyong National University, Busan 608-737, Republic of Korea

Received: April 11, 2014; Revised: June 10, 2014; Accepted: June 19, 2014

Abstract

In this study, a series of autoclave experiments were conducted in order to investigate the geochemical and mineralogical effects of carbon dioxide on deep subsurface environments. High pressure and temperature conditions of 50°C and 100 bar, which are representative environments for geological CO2 sequestration, were created in stainless- steel autoclaves for simulating the interactions in the scCO2-groundwater-mineral reaction system. Zeolite, a widespread mineral in Pohang Basin where many researches have been focused as a candidate for geological CO2 sequestration, and groundwater sampled from an 800 m depth aquifer were applied in the experiments. Geochemical and mineralogical alterations after 30 days of scCO2-groundwater-zeolite sample reactions were quantitatively examined by XRD, XRF, and ICP-OES investigations. The results suggested that dissolution of zeolite sample was enhanced under the acidic condition induced by dissolution of scCO2. As the cation concentrations released from zeolite sample increase, H+ in groundwater was consumed and pH increases up to 10.35 after 10 days of reaction. While cation concentrations showed increasing trends in groundwater due to dissolution of the zeolite sample, Si concentrations decreased due to precipitation of amorphous silicate, and Ca concentrations decreased due to cation exchange and re-precipitation of calcite. Through the reaction experiments, it was observed that introduction of CO2 could make alterations in dissolution characteristics of minerals, chemical compositions and properties of groundwater, and mineral compositions of aquifer materials. Results also showed that geochemical reactions such as cation exchange or dissolution/precipitation of minerals could play an important role to affect physical and chemical characteristics of geologic formations and groundwater.

Keywords carbon dioxide, zeolite, high pressure and temperature, geochemical reaction, dissolution

    KSEEG
    Jun 30, 2024 Vol.57 No.3, pp. 281~352

    Stats or Metrics

    Share this article on

    • kakao talk
    • line

    Related articles in KSEEG

    Economic and Environmental Geology

    pISSN 1225-7281
    eISSN 2288-7962
    qr-code Download