Assessing CO2 sequestration potential in Cenozoic basaltic rocks of Harrat Al-Shaam, Jordan

Abstract

Carbon geo-sequestration is a promising approach to mitigate greenhouse gas emissions, particularly through the long-term storage of CO₂ in suitable geological formations. This study investigates the potential of the Harrat Al-Shaam Volcanic Field (HSVF) in Jordan as a host site for CO₂ mineralization, focusing on its textural, mineralogical, and geochemical characteristics. Basaltic rocks, known for their chemical composition rich in calcium (Ca), iron (Fe), and magnesium (Mg), demonstrate a favorable capacity for CO₂ sequestration. They undergo chemical reactions with injected CO₂ and brine, leading to the formation of stable carbonate minerals. In this work, we conducted a series of laboratory experiments involving the injection of supercritical CO₂ mixed with brine and freshwater into basalt core and powder samples to evaluate their mineralization potential under controlled conditions. Parameters such as mineral composition, alteration, and porosity were assessed. Microscopic investigations and geochemical analyses revealed changes in textural and mineralogical composition after CO₂ treatment. Notably, rapid neutralization of carbonic acid during injection was observed, resulting in the formation of calcite through water-rock reactions, which underscores the swift mineralization process inherent to these basaltic formations. The study confirms the moderate potential for carbonate mineralization and CO₂ storage capacity within the basaltic rocks of HSVF, attributed to their alkaline composition, enrichment of Ca and Fe-bearing minerals, and structural features such as fractures that enhance porosity and permeability. These findings highlight the effectiveness of mafic rocks as reliable candidates for geological CO₂ storage and indicate a need for further research to fully explore their long-term sequestration capabilities.