CO2-removal news

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

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

Danny Otto, Nils Matzner IN: C 10, 25, https://doi.org/10.3390/c10010025

Regional case studies investigating the dynamics that may facilitate or impede the broader adoption of CDR methods in spatially explicit settings are critically absent. Understanding implementation contexts on the ground is vital, and comparing them across different removal methods is essential for effectively scaling up CDR. 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 six CDR methods.

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Meissner (2024): A case for promoting negative emission technologies: learning from renewable energy support

Leonie P. Meissner IN: Carbon Management 15 (1), https://doi.org/10.1080/17583004.2024.2319787

With renewable energy technologies, there has already been the introduction and expansion of a clean technology that faced similar obstacles as negative emission technologies—high up-front costs, limited competitiveness, and low public perception. This article compares NET policy proposals with the lessons learned from RET support.

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Chapter: Markus & Schaller (2024): Land-Use Implications of Carbon Dioxide Removal: An Emerging Legal Issue?

Till Markus, Romina Schaller IN: Ginzky, H., et al. International Yearbook of Soil Law and Policy 2022. Springer, Cham. https://doi.org/10.1007/978-3-031-40609-6_5

Science has expressed concerns that CDR as a means to fight climate change could potentially increase competition for land and contribute to soil degradation. This paper aims to map out the potential land-use and soil implications of CDR to identify possible lines of political and legal conflicts.

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PhD-Thesis: Ocean Alcalinity Enhancement: Tool to Mitigate Climate Change

Jakob Bang Rønning, University of Southern Denmark, https://doi.org/10.21996/p2f3-rp88

This thesis explores the potential of ocean alkalinity enhancement as an ocean-based carbon dioxide removal method, specifically focusing on alkaline minerals for mineral-based OAE as novel avenues for climate change mitigation. As global decarbonization is obliged, integrating diverse CDR technologies is essential to effectively counter and reverse the ongoing trend of global CO2 emissions in the atmosphere. This thesis studied the nuanced aspects of mineral-based OAE, emphasizing the potential of alkaline minerals such as dolomite, limestone, and olivine. The study aims to examine their impact on seawater carbon chemistry and primary producers. 

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