CO₂-removal News

Reports

Biochar Permanence Report: Unlocking the Potential of Biochar: A Closer Look at Its Permanence

Bier, H., Lerchenmüller, H., European Biochar Industry, March 14, 2024

In the quest to understand permanence of biochar, our report sheds light on critical findings from two scientific publications by Sanei et al. (2024) and Azzi et al. (2024). The report, authored by Secretary General Harald Bier and Board Chairman Hansjörg Lerchenmüller at EBI, offers a comparative analysis of results from the two studies. It reveals a key gap: most incubation experiments use carbonized material that is not representative of biochar produced commercially today. Moreover, these studies often lack detailed characterization of biochar fractions, hindering a comprehensive understanding of their properties. Another key point posited in the paper is that the observed degradation rates shown in incubation experiments are consistent with the size of the labile fractions that are known to be easily degradable.

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Peer-reviewed Publications

Zhu et al. (2024): Confinement Effects on Moisture-Swing Direct Air Capture

Yaguang Zhu, Austin Booth, Kelsey B. Hatzell IN: Environmental Science & Technology Letters, https://doi.org/10.1021/acs.estlett.3c00712

Direct air capture technologies are energy intensive and often utilize pressure and temperature swings for sorbent regeneration. An alternative approach, called moisture-swing direct air capture, relies on the hydrolysis of a confined anion to produce hydroxide anions. These hydroxide anions are active sites for CO2 capture. Here, the authors examine how confinement affects moisture-swing CO2 capture and regeneration mechanisms.

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Books

Chapter: Lukas Schuett (2024): Permanence and Liability: Legal Considerations on the Integration of Carbon Dioxide Removal into the EU Emissions Trading System

Lukas Schuett IN: Transnational Environmental Law, https://doi.org/10.1017/S2047102524000013

This article examines how carbon dioxide (CO2) removal credits can be integrated into the European Union (EU) Emissions Trading System (ETS), focusing on questions of permanence and climate liability. It identifies challenges within the integration process and analyzes approaches from practice and literature to cultivate learning. These approaches apply different strategies to address the issue of permanence, including temporary credit issuance, granting credits once a certain number of carbon tonne-years have been accumulated, or issuing credits at the beginning of the project period and relying on liability instead. Drawing from the findings of this research, the article presents legal considerations that may inform a proposal for an EU legislative act on the integration of carbon removal credits into the EU ETS.

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Peer-reviewed Publications

Sovacool et al. (2024): The sociotechnical dynamics of blue carbon management: Testing typologies of ideographs, innovation, and co-impacts for marine carbon removal

Benjamin K. Sovacool, Chad M. Baum, Sean Low, Livia Fritz IN: Environmental Science & Policy, 155, 103730, https://doi.org/10.1016/j.envsci.2024.103730

Blue carbon, the preservation and enhancement of marine and coastal ecosystems for carbon removal, is treated as a potentially cost-effective way to capture and store carbon, generate community co-benefits, and implement conservation and climate agendas. However, blue carbon ecosystems are among the most unproven climate intervention options, in part given their status as highly threatened systems which moreover have critical connections to planetary health and food security. Based on extensive place-based field research and document analysis, this study examines three blue carbon innovations: coral reef preservation in Australia, seagrass restoration in the United Kingdom, and macroalgae (seaweed) cultivation and deep ocean storage in the United States. Empirically, it utilizes an extensive, original dataset of expert interviews (N=46), site visits (N=38) and document analysis undertaken over late 2022 and 2023.

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Reports

Word Ocean Review 8: The Ocean – A Climate Champion? How to Boost Marine Carbon Dioxide Uptake

by Sina Löschke together with Thorben Amann, Christian Baatz, Miranda Böttcher, Oliver Geden, David P. Keller, Achim Kopf, Christine Merk, Sebastian Milinski, Katja Mintenbeck, Andreas Oschlies, Julia Pongratz, Alexander Proelß, Gregor Rehder, Wilfried Rickels, Ulf Riebesell, Michael Sswat, Lukas Tank, Klaus Wallmann, Lennart Westmark, Mirco Wölfelschneider, Martin Zimmer, maribus, March 14, 2024

What action should we take for the effective mitigation of climate change? Measures to avoid greenhouse gas emissions are surely the main priority – but the truth is that in the coming decades, we will also have to remove large quantities of carbon dioxide from the atmosphere and store it securely. Can – indeed, should – the ocean aid us in this task? The new World Ocean Review (WOR 8) explores this issue with reference to the oceans‘ role in the Earth’s carbon cycle and looks at the benefits, risks and knowledge gaps around the main marine carbon dioxide removal techniques.

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Peer-reviewed Publications

Liu et al. (2024): Sustainable utilization of concrete slurry waste in eco-friendly artificial lightweight cold-bonded aggregates: An alternative pathway for efficiently sequestrating CO2

Jun Liu, Lei Cheng, Hesong Jin, Feng Xing IN: Construction and Building Material, 421, 135759, https://doi.org/10.1016/j.conbuildmat.2024.135759

Concrete slurry waste (CSW) has the potential of capturing or sequestering CO2. This study designed the low-carbon artificial lightweight cold-bonded aggregates with ultra-high volume of CSW, OSP and MSWIBA (CSW-ALCBAs), and the CO2 sequestrating, compressive strength, and physical properties, leaching toxicity and CO2 emissions of CSW-ALCBAs were investigated. Meanwhile, a novel carbonization device was designed to quantitatively evaluate the potential of CSW-ALCBAs for CO2 adsorption.

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Scientific Theses

PhD-thesis: Concentrating Alkalinity for Direct Air Capture of Carbon Dioxide: Using Osmotic Pressure for Concentration and Separation

Anatoly Rinberg, Harvard University, https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37377926

First, the author proposes a new approach for removing atmospheric CO2, the alkalinity concentration swing (ACS), driven by concentrating and diluting aqueous alkaline solution, which increases and decreases the partial pressure of CO2 of the solution, respectively. Second, he improves on the ACS process by introducing a selectivity step, which separates bicarbonate ions from carbonate ions. A theoretical investigation reveals that bicarbonate-enrichment allows for reaching higher cycle capacity, higher CO2 partial pressure, and improved absorption rates. Third, nanofiltration is experimentally studied, and confirmed as a mechanism to enrich bicarbonate ions, reaching bicarbonate-carbonate selectivity factors above 30. Fourth, he experimentally demonstrates the ability to use reverse osmosis, a membrane-based separation process driven by applied pressure, as a method for concentrating alkalinity.

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Peer-reviewed Publications

Wenger & D’Alessandro (2024): Improving the Sustainability of Electrochemical Direct Air Capture in a 3D Printed Redox Flow Cell

Samuel R. Wenger & Deanna M. D’Alessandro IN: ACS Sustainable Chemistry & Engineering https://doi.org/10.1021/acssuschemeng.3c07866

To enable the scale-up of electrochemical direct air capture (DAC), it is critical to enhance the sustainability of the process by maximizing efficiency and optimizing for targeted durability. Currently, many of the organic molecules reportedly used for electrochemical CO2 capture suffer from degradation upon extended redox cycling in the presence of oxygen, which generates chemical waste. Furthermore, off-the-shelf electrochemical flow cells─an integral piece of equipment for redox flow processes─cost thousands of dollars to procure. In this work, we addressed these challenges by exploring the DAC cyclability of five organic molecules.

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Peer-reviewed Publications

Science – Bufe et al. (2024): CO2 drawdown from weathering is maximized at moderate erosion rates

Aaron Bufe, Jeremy K. C. Rugenstein, Niels Hovius IN: Science, DOI: 10.1126/science.adk0957

 Solute-chemistry datasets from mountain streams in different orogens isolate the impact of erosion on silicate weathering—a carbon dioxide (CO2) sink—and coupled sulfide and carbonate weathering—a CO2 source. Contrasting erosion sensitivities of these reactions produce a CO2-drawdown maximum at erosion rates of ~0.07 millimeters per year. Thus, landscapes with moderate uplift rates bolster Earth’s inorganic CO2 sink, whereas more rapid uplift decreases or even reverses CO2 sequestration. This concept of an “erosion optimum” for CO2 drawdown reconciles conflicting views on the impact of mountain building on the carbon cycle and permits estimates of geologic CO2 fluxes dependent upon tectonic changes.

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Peer-reviewed Publications

Shoaib et al. (2024): Estimating Phytosequestration Capacity And The Effect Of Environmental Pollution On Carbon Sequestration Of Some Plant Species And Its Chlorophyll Correlation

Affhan Shoaib, Aiman Sultan, Sana Minai, Sohaib Ahmed, M. Hashim Zuberi IN: Fuuast Journal Of Biology, 13, 2

Current work is focused on exploring carbon dioxide uptake by different methods of green biotechnology and how environmental pollution affects that uptake. The study examined how the relationship between environmental pollution and carbon sequestration can be optimized by the technique of green biotechnology which affects the overall plant health. For this purpose, leaves from twenty-six plant species including Michelia, Anona Squamosa, Catharantha roseus, Elaeis Guineenis, Hibiscus rosa sinensis, and Epipremnun pinnatum were taken and divided into two sets. One set was washed with water and the other one was left with dirt on it to demonstrate the effect of pollution on carbon sequestration.

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