CO₂-removal News

Nature – Mignone et al. (2024): Drivers and implications of alternative routes to fuels decarbonization in net-zero energy systems

Bryan K. Mignone, Leon Clarke, James A. Edmonds, Angelo Gurgel, Howard J. Herzog, Jeremiah X. Johnson, Dharik S. Mallapragada, Haewon McJeon, Jennifer Morris, Patrick R. O’Rourke, Sergey Paltsev, Steven K. Rose, Daniel C. Steinberg, Aranya Venkatesh IN: Nature Communications 15, 3938, https://doi.org/10.1038/s41467-024-47059-0

Energy transition scenarios are characterized by increasing electrification and improving efficiency of energy end uses, rapid decarbonization of the electric power sector, and deployment of carbon dioxide removal (CDR) technologies to offset remaining emissions. Although hydrocarbon fuels typically decline in such scenarios, significant volumes remain in many scenarios even at the time of net-zero emissions. While scenarios rely on different approaches for decarbonizing remaining fuels, the underlying drivers for these differences are unclear. Here we develop several illustrative net-zero systems in a simple structural energy model and show that, for a given set of final energy demands, assumptions about the use of biomass and CO2 sequestration drive key differences in how emissions from remaining fuels are mitigated.

LINK

Qian et al. (2024): Investigations on carbon-sequestration optimization of recycled coarse-aggregate and its effects on concrete performances

Rusheng Qian, Lin Wan-Wendner, Chengqi Yang, Ruze Zhao, Zhibo Ye, Deyu Kong, Yong Zhang IN: Journal of Building Engineering 90, 109453, https://doi.org/10.1016/j.jobe.2024.109453

Recycled coarse-aggregate (RCA) derived from waste concrete can be re-used for concrete preparation, which is now limited due to its drawbacks such as micro-cracks, high-porosity, and reduced concrete strengths. To remedy these deficiencies, carbon-sequestration was employed in this study to enhance RCA and the conditions were optimized, including the temperature (20 °C–40 °C), pressure (0.1 MPa–0.3 MPa), time (5 h–24 h) and initial water content (25%–75 %).

LINK

Liu et al. (2024): Which Provinces Will Be the Beneficiaries of Forestry Carbon Sink Trade? A Study on the Carbon Intensity–Carbon Sink Assessment Model in China

Changxi Liu, Enjun Xia, Jieping Huang IN: Forests 15 (5), 816, https://doi.org/10.3390/f15050816

To mitigate the discrepancy between economic development levels and carbon sequestration capacities among Chinese provinces, this study presents an assessment methodology that analyzes over 100 types of natural and plantation forests using forest age and biomass expansion factors. This study presents a model that can significantly support the efforts of both China and the whole world to achieve carbon neutrality through the improved management of forest carbon sinks. 

LINK

Adun et al. (2024): Sustainability implications of different carbon dioxide removal technologies in the context of Europe’s climate neutrality goal

Humphrey Adun, Jeffrey Dankwa Ampah, Olusola Bamisile, Dilber Uzun Ozsahin, Iain Staffell IN: Sustainable Production and Consumption 47, 598-616, https://doi.org/10.1016/j.spc.2024.04.003

Given its role as a leader in global climate actions, the European Union is expected to take a leading role in CDR developments: yet there is a lack of depth in the region’s CDR strategy and deployment. A comprehensive CDR approach based on integrated assessment modelling for the EU is important to give valuable insights into optimal CDR-based mitigation pathways regarding scalability, technology readiness, trade-offs with the Earth system, and deployment strategies. Here, the authors have used the GCAM-CDR v1.0 to model a diverse novel CDR portfolio of BECCS, DACCS, TEW and OEW in a mid-century carbon neutrality target.

LINK

Smith et al. (2024): Residual emissions in long-term national climate strategies show limited climate ambition

Harry B. Smith, Naomi E. Vaughan, Johanna Forster IN: One Earth 7, https://doi.org/10.1016/j.oneear.2024.04.009

Net-zero targets imply a need to compensate for residual emissions through the deployment of carbon dioxide removal methods. Yet the extent of residual emissions within national climate plans, alongside their distribution, is largely unexplored. Here, the authors analyze 71 long-term national climate strategies to understand how national governments engage with residual emissions.

LINK

Otto & Matzner (2024): Let Us Get Regional: Exploring Prospects for Biomass-Based Carbon Dioxide Removal on the Ground

Danny Otto, Nils Matzner IN: Journal of Carbon Research, https://doi.org/10.3390/c10010025

This paper aims to address this research gap by comparatively examining the development of biomass-based CDR in three regions of Germany. Taking an exploratory approach, we conducted surveys in these regions to gain insight into stakeholder perceptions of the following six CDR methods: forest management, agriculture and soil carbon, long-lasting building materials, rewetting of peatlands and paludiculture, biochar, and bioenergy with carbon capture and storage. In this article, the authors present the results of the stakeholder survey, which offers multiple perspectives that can shape future studies of regional implementation and yield policy-relevant guidance. Although the research primarily focuses on the regional level in Germany, it sheds light on various conflicts, uncertainties, and potentials that are likely to be relevant for the rollout of CDR in other countries.

LINK

Ho et al. (2024): A CO2 removal technology based on mineral carbonation and the stability of product carbon storage in a cement matrix

Hsing-Jung Ho, Yoshito Izumi, Atsushi Iizuka IN: Environmental Technology & Innovation, 34, 103623, https://doi.org/10.1016/j.eti.2024.103623

This paper proposes a mineral direct air carbon capture and storage in product technology newly designed by a mineral carbon capture reactor through direct feeding of atmospheric CO2. Additionally, a novel concrete mix for use as CO2-storing (CDS) concrete is proposed. This mix contains recarbonates generated using treated water with high Ca content at a ready-mixed concrete plant. The CDS concrete, with a recarbonate content in the range of 2–10% of cement, exhibited very similar initial and mechanical properties compared with ordinary concrete. The CO2 release from the recarbonate in a cement matrix under acidic corrosion and the thermal decomposition were assessed, and the findings are discussed.

LINK

Qian et al. (2024): Investigations on carbon-sequestration optimization of recycled coarse-aggregate and its effects on concrete performances

Rusheng Qian, Lin Wan-Wendner, Chengqi Yang, Ruze Zhao, Zhibo Ye, Deyu Kong, Yong Zhang IN: Journal of Building Engineering, 90, 109453, https://doi.org/10.1016/j.jobe.2024.109453

Recycled coarse-aggregate (RCA) derived from waste concrete can be re-used for concrete preparation, which is now limited due to its drawbacks such as micro-cracks, high-porosity, and reduced concrete strengths. To remedy these deficiencies, carbon-sequestration was employed to enhance RCA and the conditions were optimized, including the temperature (20 °C–40 °C), pressure (0.1 MPa–0.3 MPa), time (5 h–24 h) and initial water content (25%–75 %). There parameters were optimized based on the orthogonal test with scheme L9(34), which was evaluated based on RCA carbon-sequestration amount as well as its properties. With the optimized parameters, RCA was enhanced as CRCA. Both RCA and CRCA were utilized to fully replace natural coarse-aggregate (NCA) in concrete and concrete basic performances were investigated systematically, including strengths, shrinkage and medium transport properties. 

LINK

Zhu et al. (2024): Sustainable carbon sequestration via olivine based ocean alkalinity enhancement in the east and South China Sea: Adhering to environmental norms for nickel and chromium

Tianqiang Zhu, Liwen Zheng, Feng Li, Jihua Liu, Wen Zhuang IN: Science of The Total Environment, 930, 172853, https://doi.org/10.1016/j.scitotenv.2024.172853

This study aims to evaluate the feasibility and potential of olivine-based ocean alkalinity enhancement (OAE) for the removal of atmospheric CO2 and its storage in seawater as bicarbonates in the East and South China Seas (ESCS). A particular focus is placed on the potential ecological impacts arising from the release of nickel (Ni) and chromium (Cr) during the olivine weathering process. The authors considered two extreme scenarios: one where Ni and Cr are entirely retained in seawater, and another where they are completely deposited in sediments.

LINK

Edwards et al (2024): Modeling direct air carbon capture and storage in a 1.5 °C climate future using historical analogs

Morgan R. Edwards, Zachary H. Thomas, Gregory F. Nemet, Sagar Rathod, Jenna Greene, Kavita Surana, Kathleen M. Kennedy, Jay Fuhrman, Haewon C. McJeo IN: PNAS, https://doi.org/10.1073/pnas.2215679121

Here, the authors present an approach to model adoption of early-stage technologies such as CDR and apply it to direct air carbon capture and storage (DACCS). Our approach combines empirical data on historical technology analogs and early adoption indicators to model a range of feasible growth pathways. They use these pathways as inputs to an integrated assessment model (the Global Change Analysis Model, GCAM) and evaluate their effects under an emissions policy to limit end-of-century temperature change to 1.5 °C. Adoption varies widely across analogs, which share different strategic similarities with DACCS.

LINK