Unlocking the Potential of In Situ Carbon Mineralization in the Mafic and Ultramafic Rocks of Pakistan

Abstract Pakistan contributes very little to global <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> emissions yet is frequently ranked among the most climate-vulnerable countries. Carbon capture and storage (CCS) represents an effective method for addressing climate change. Among various CCS techniques, carbon capture and storage by mineralization, specifically in situ carbon mineralization (ISCM), in mafic and ultramafic rocks, is receiving considerable attention for mitigating the effects of climate change and exploring sustainable ways to manage and utilize <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> . Several successful pilot-scale projects have been carried out globally (e.g., CarbFix, Wallula), demonstrating the potential for rapid <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> sequestration. This review synthesizes global insights on ISCM and contextualizes these results within the framework of Pakistan as a regional case study. Pakistan has extensive mafic-ultramafic rocks dominated by Ca/Mg-rich silicate minerals, including serpentine, olivine, and other minerals. This research estimates the percentage of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> that can be sequestered in mafic (Ranikot Group, Chalt Volcanic Group, Parh Group Basalts) and ultramafic rocks (Chilas Complex, Jijal Complex, Dargai Ophiolite, Bela Ophiolite, Muslim Bagh, Waziristan Ophiolite) in Pakistan. The Parh Group Basalts can sequester 15.30–52.09 g <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> per gram of rock, and the Jijal Complex can sequester 26.71–71.51 g <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> per gram of rock. The findings of this review suggest that basalts and peridotite/ophiolite are well-suited for ISCM compared to other rocks for quick and large-scale <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> sequestration. The outcomes will provide insights into ISCM and its feasibility for extensive <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C upper O 2" display="inline" overflow="scroll"> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> sequestration, helping to achieve global net-zero objectives.