The increasing level of anthropogenic CO₂ in the atmosphere has made it imperative to investigate an efficient method for carbon sequestration. Geological carbon sequestration presents a viable path to mitigate greenhouse gas emissions by sequestering the captured CO₂ deep underground in rock formations to store it permanently. Geochemistry, as the cornerstone of geological CO₂ sequestration (GCS), plays an indispensable role. Therefore, it is not just timely but also urgent to undertake a comprehensive review of studies conducted in this area, articulate gaps and findings, and give directions for future research areas. This paper reviews geochemistry in terms of the sequestration of CO₂ in geological formations, addressing mechanisms of trapping, challenges, and ways of mitigating challenges in trapping mechanisms; mineralization and methods of accelerating mineralization; and the interaction between rock, brine, and CO₂ for the long-term containment and storage of CO₂. Mixing CO₂ with brine before or during injection, using microbes, selecting sedimentary reservoirs with reactive minerals, co-injection of carbonate anhydrase, and enhancing the surface area of reactive minerals are some of the mechanisms used to enhance mineral trapping in GCS applications. This review also addresses the potential challenges and opportunities associated with geological CO₂ storage. Challenges include caprock integrity, understanding the lasting effects of storing CO₂ on geological formations, developing reliable models for monitoring CO₂–brine–rock interactions, CO₂ impurities, and addressing public concerns about safety and environmental impacts. Conversely, opportunities in the sequestration of CO₂ lie in the vast potential for storing CO₂ in geological formations like depleted oil and gas reservoirs, saline aquifers, coal seams, and enhanced oil recovery (EOR) sites. Opportunities include improved geochemical trapping of CO₂, optimized storage capacity, improved sealing integrity, managed wellbore leakage risk, and use of sealant materials to reduce leakage risk. Furthermore, the potential impact of advancements in geochemical research, understanding geochemical reactions, addressing the challenges, and leveraging the opportunities in GCS are crucial for achieving sustainable carbon mitigation and combating global warming effectively.

Carbon Capture and Storage (CCS) is a vital climate mitigation strategy aimed at reducing CO₂ emissions from industrial and energy sectors. This review presents a comprehensive analysis of CCS technologies, focusing on capture methods, transport systems, geological storage, geomechanical and geochemical aspects, modeling, risk assessment, monitoring, and economic feasibility. Among capture technologies, pre-combustion capture is identified as the most efficient (90–95%) due to its high purity and integration potential. Notably, most operational CCS projects in 2025 utilize pre-combustion capture, particularly in hydrogen production and natural gas processing. For geological storage, saline aquifers and depleted oil and gas reservoirs are highlighted as the most promising due to their vast capacity and proven containment. In the transport phase, pipeline systems are considered the most effective and scalable method, offering high efficiency and cost-effectiveness for large-scale CO₂ movement, especially in the supercritical phase. The study also emphasizes the importance of hybrid integrated risk assessment models, such as NRAP-Open-IAM, which combine deterministic simulations with probabilistic frameworks for robust site evaluation. In terms of monitoring, Seismic monitoring methods are regarded as the most reliable subsurface technique for tracking CO₂ plume migration and ensuring storage integrity. Economically, depleted reservoirs offer the most feasible option when integrated with existing infrastructure and supported by incentives like 45Q tax credits. The review concludes that successful CCS deployment requires interdisciplinary innovation, standardized risk protocols, and strong policy support. This work serves as a strategic reference for researchers, policymakers, and industry professionals aiming to scale CCS technologies for global decarbonization.

Geological carbon sequestration (GCS) in deep saline aquifers is a critical climate mitigation strategy, but its long-term effectiveness depends on the combined impact of structural, residual, solubility, and mineral trapping mechanisms. Despite substantial research done on individual trapping processes, integrated evaluations under realistic reservoir conditions remain limited, reducing the predictive reliability of CO₂ storage performance. This study develops a high-resolution, 3D compositional model of the Strawn formation in northeast King County, Texas, using CMG-GEM software to investigate coupled physical and geochemical trapping processes. Unlike the previous studies, this model couples all four trapping mechanisms in a single framework, providing a quantitative and mechanistic understanding of CO₂ fate in the subsurface. The validation of the model grid was performed using grid sensitivity analysis on selected performance parameters. A comparative analysis is presented between two-dimensional and three-dimensional modeling approaches to highlight the importance of spatial dimensionality in accurately capturing CO₂ plume dynamics and assessing storage efficiency. Results show that solubility trapping, when effectively combined with structural and residual mechanisms, yields the highest amount of CO₂ sequestered (43%), followed by mineral trapping (40%). A comprehensive sensitivity analysis, conducted on factors affecting such solubility trapping, demonstrates that the efficiency of the integrated trapping increases with higher injection rates, prolonged injection years, higher porosity, elevated pressures, lower temperatures, and reduced vertical and horizontal permeabilities. These findings offer crucial insights for optimizing reservoir and operational parameters to improve containment and long-term storage. The integrated modeling approach presented here offers a robust and transferable framework for evaluating and designing site-specific carbon storage systems on a scale.

Assessing methane (CH₄) emissions is critical for mitigating the environmental impact of greenhouse gases (GHGs). Optical Gas Imaging (OGI) technologies have emerged as effective tools for gas leak detection and quantification; however, their performance under varying environmental conditions and gas compositions remains insufficiently understood. In particular, previous studies have largely overlooked the combined effects of ambient temperature variations and Carbone. Dioxide (CO₂) interference on both detection sensitivity and quantification accuracy. This study addresses this gap by systematically investigating the influence of temperature and CO₂ on methane detection and quantification using an infrared OGI camera coupled with real-time analysis software. Logistic regression was employed to model detection probability under two temperature conditions at a fixed distance of 45 m. Results show that at 30 °C, the system achieved 50% and 90% detection probabilities at 5.51 and 11.30 kg/h, respectively. In contrast, at −7 °C, detection reliability decreased due to increased false positives, preventing the establishment of robust detection thresholds. However, methane quantification accuracy improved under colder conditions, with 90% of leaks correctly quantified compared to 60% in warmer environments. Furthermore, the presence of CO₂ completely inhibited methane detection and quantification. These findings demonstrate the significant and previously underexplored impact of temperature and gas composition on OGI performance, highlighting critical limitations in real-world applications and providing new insights for improving methane monitoring strategies.