CO2-removal News

Wang et al. (2025): Hydrate Distribution and Its Effects on CO₂ Sequestration in Oceanic Muddy-Silt-Type Reservoirs

Xinru Wang, Lei Zhang, Bingbing Chen, Tao Yu, Mingjun Yang, Qiang Fu, Weixin Pang, Yongchen Song, IN: ACS Energy & Fuels, https://doi.org/10.1021/acs.energyfuels.5c00665

CO₂ hydrate formation during the injection process in an oceanic reservoir offers extended sequestration capacity and extra sealing. However, review of the literature reveals that the role of injection strategy on hydrate distribution remains unclear. Therefore, in this work, the reservoir was rebuilt first using muddy-silt-type marine soil from the station of LW3 in the northern part of the South China Sea. Then, the characteristics of hydrate distribution in the reservoirs using water/CO₂ injection mode were compared, and their effects on CO₂ sequestration were analyzed.

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Sun et al. (2025): Intensive oyster farming enhances carbon storage in sediments over decades

Xin Sun, Ramón Filgueira, Yihua Sun, Ming Han, Qisheng Tang & Yao Sun, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-025-02358-2

Clarifying the oyster’s carbon budget of their farming ecosystem defines this industry’s future. Through biodeposition, oyster enhances the vertical flux of organic carbon. However, the cycling of sedimented carbon before being separated from the biosphere remains unclear. Here, the authors constructed the chronologic profiles of the sediment cores from a typical oyster farm with approximately 50 years of farming history. The profiles corresponded with the farming development, environment, associated biogenic elements, and microbial communities.

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Nature – Moustakis et al. (2025): No compromise in efficiency from the co-application of a marine and a terrestrial CDR method

Yiannis Moustakis, Hao-Wei Wey, Tobias Nützel, Andreas Oschlies & Julia Pongratz, IN: Nature Communications, https://doi.org/10.1038/s41467-025-59982-x

Modelled pathways consistent with the Paris Agreement goals to mitigate warming typically include the large-scale application of Carbon Dioxide Removal (CDR), which can include both land- and marine-based CDR methods. However, the Earth system responses and feedbacks to scaling up and/or combining different CDR methods remain understudied. Here, these are assessed by employing two Earth System Models, with a multifactorial setup of 42 emission-driven simulations covering the whole spectrum of Afforestation/Reforestation (0–927 Mha) and of Ocean Alkalinity Enhancement (0–18 Pmol) over the 21st century.

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Zhang et al. (2025): Hidden Acidification Challenges in Electrochemical Ocean Decarbonization

Wei Zhang, Adnan Ozden, Yu Yang, Aoni Xu, Fengwang Li, IN: ACS Energy Letters, https://doi.org/10.1021/acsenergylett.5c00900

Electrochemical direct ocean capture (eDOC) is an emerging methodology for carbon capture. However, our comprehensive thermodynamic and initial kinetic analyses reveal critical challenges inherent in the electrochemical pH-swing process. Specifically, the mixture of treated ocean water post-eDOC fails to achieve complete neutralization, resulting in unintended ocean acidification. This issue stems from the disproportionate impacts of acidification and alkalinization on dissolved inorganic carbon dynamics and hydroxide precipitation.

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Li et al. (2025): Direct air capture-assisted sustainable fuel solution in maritime sector: a carbon footprint perspective

Shuangjun Li, Zhenyu Du, Junyao Wang, Hao Wang, Xiangkun Elvis Cao, Runkai Chen, Yujia Pang, Shuai Deng, Ondřej Mašek, Xiangzhou Yuan & Ki Bong Lee, IN: Discover Sustainability, https://doi.org/10.1007/s44246-025-00209-5

Carbon emissions reduction within the maritime sector is pivotal for realizing zero-carbon goals and mitigating climate impacts. Adopting renewable carbon fuels presents a potent strategy. It is necessary to have a comprehensive understanding of its negative carbon attributes and enduring contributions to future development based on carbon footprint assessment. By using the CO₂ captured through direct air capture (DAC) technology and the H₂ obtained via water electrolysis as feedstock, electro-methanol (e-methanol) can be produced under renewable energy-driven conditions. Owing to the environmental benefits and economic feasibility of e-methanol, the authors highlight its potential as a practical alternative to traditional fossil fuel-based technical scenarios.

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Nature – Lahiri et al. (2025): Complex carbonate phases drive geologic CO₂ mineralization

Nabajit Lahiri, Libor Kovarik, Sandra D. Taylor, Jarrod V. Crum, Eugene S. Ilton, Charles T. Depp, Quin R. S. Miller & H. Todd Schaef, IN: Nature Communications Earth & Environment, https://doi.org/10.1038/s43247-025-02273-6

Geologic carbon sequestration in mafic and ultramafic reservoirs is a scalable strategy for carbon dioxide removal, offering permanent storage via mineralization as stable carbonates. However, there is limited information on the structure and composition of key mineralization endpoints during sequestration. Here, the authors unravel the atomic structure, composition, and nanoscale morphology of carbonates recovered from a field-scale demonstration of CO₂ mineralization in basalt.

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Norouzpour et al. (2025): Activation methods for enhancing CO₂ mineralization via mine tailings—A critical review

Milad Norouzpour, Rafael M. Santos, Yi Wai Chiang, IN: Carbon Capture Science & Technology, https://doi.org/10.1016/j.ccst.2025.100430

Greenhouse gas emissions from fossil fuel combustion exacerbate global warming, necessitating scalable and cost-effective carbon capture and storage (CCS) strategies. Mineral carbonation has emerged as a promising solution, permanently converting carbon dioxide (CO₂) into stable carbonates while simultaneously repurposing mine tailings for sustainable waste management. Ultramafic and mafic mine tailings, which are rich in Mg- and Ca-bearing minerals, provide abundant and reactive feedstocks for CO₂ sequestration. This review examines the chemical, mineralogical, and physical characteristics of selected tailings from nickel, asbestos, diamond, gold, iron, and platinum group metal (PGM) mines to assess their carbonation potential, and also introduces a mineral-specific analysis of mechanical activation effects across these materials.

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Zhang et al. (2025): Hidden Acidification Challenges in Electrochemical Ocean Decarbonization

Wei Zhang, Adnan Ozden, Yu Yang, Aoni Xu, Fengwang Li, IN: ACS Energy Letters, https://doi.org/10.1021/acsenergylett.5c00900

Electrochemical direct ocean capture (eDOC) is an emerging methodology for carbon capture. However, the authors’ comprehensive thermodynamic and initial kinetic analyses reveal critical challenges inherent in the electrochemical pH-swing process. Specifically, the mixture of treated ocean water post-eDOC fails to achieve complete neutralization, resulting in unintended ocean acidification. This issue stems from the disproportionate impacts of acidification and alkalinization on dissolved inorganic carbon dynamics and hydroxide precipitation.

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Xu et al. (2025): Microbial Mechanisms of Carbon Sequestration Discrepancy between Broadleaf and Moso Bamboo Forests

Yaowen Xu, Chuping Wu, Jiejie Jiao, Liangjin Yao, IN: Frontiers in Microbiology, https://doi.org/10.3389/fmicb.2025.1580720

In subtropical areas, broadleaf forests are being increasingly converted into Moso bamboo (Phyllostachys pubescens) forests. However, few studies have systematically compared soil organic carbon (SOC) between broadleaf and Moso bamboo forests. Therefore, the authors investigated SOC content and relative contributions of microbial and plant residues to SOC in broadleaf and Moso bamboo forests using biomarkers.

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Ying et al. (2025): Waste rice straw biochar recycled concrete: Carbon sequestration, durability and microstructure

Xuejin Ying, Xiao Zhao, Mao Ye, Cheng Wang, Baojian Zhan, Jianjun Zhao, Zixin He, Xiaoxiong Nie, IN: Journal of Cleaner Production, https://doi.org/10.1016/j.jclepro.2025.145690

Adding biochar to recycled concrete (RC) is considered an effective method to enhance carbon sequestration efficiency. This study introduces a sustainable and low-carbon green building material that replaces a portion of cement with waste rice straw biochar (WRSB) in RC and undergoes CO₂ curing.

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