CO2-removal news

Peer-reviewed Publications

Douglas et al. (2025): Drivers of Regional Variation in the De-Emergence of Climate Change under Negative Emissions

Hunter C. Douglas, Laura E. Revell, Manoj Joshi, Andrew King, Luke J. Harrington, David J. Frame IN: Journal of Climate, 38, https://doi.org/10.1175/JCLI-D-24-0257.1

A central question of climate change impact assessments is identifying when the signal of change emerges from the noise of natural variability, though to date, this framework has been almost exclusively applied under warming conditions. In this work, the authors investigate the phenomenon of de-emergence, where temperatures rise beyond a given threshold and subsequently drop back below that threshold as forcing reverses. Large-scale carbon dioxide removal (CDR), also referred to as negative emissions, has been proposed to lower global average temperatures and to mitigate damage to the Earth system, though the regional effects of this have been understudied to date. Here, the authors analyze the results of eight Earth system models (ESMs) that participated in the CDR Model Intercomparison Project (CDRMIP).

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Peer-reviewed Publications

Xu & Reinhard (2025): Evaluating the carbon capture potential of industrial waste as a feedstock for enhanced weathering

Pengxiao Xu, Christopher T Reinhard IN: Envrionmental Research Letters, 2025, https://doi.org/10.1088/1748-9326/adc020

One prominent CDR approach is enhanced rock weathering (ERW), in which crushed silicate rock is applied on land or in the open ocean to accelerate natural weathering processes that absorb carbon dioxide from Earth’s ocean-atmosphere system. However, in addition to a range of potential environmental, socioeconomic, and ethical issues associated with this pathway, bottlenecks in feedstock sourcing represent a key barrier for deployment of ERW at scale. Here, the authors evaluate the potential of silicate wastes produced from industrial processes — such as steel slag and cement waste — as feedstocks for the enhanced weathering process. An empirical model that links industrial alkaline waste production to gross domestic product at purchase power parity [GDP(PPP)] is developed to forecast waste production in the alternative futures described by the Shared Socioeconomic Pathway (SSP) framework.

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Peer-reviewed Publications

Han et al. (2025): An integrated solution to mitigate climate change through direct air capture and diabatic compressed air energy storage

Yide Han, Yurong Liu, Xin Peng, Bo-Yu Peng, Yuxing Ding, Wenli Du, Weimin Zhong, Feng Qian IN: Energy Conversion and Management, 26, https://doi.org/10.1016/j.ecmx.2025.100959

Direct air capture (DAC) is a technology designed to capture CO2 directly from ambient air for carbon removal, while compressed air energy storage (CAES) involves compressing and storing air for later use in energy generation. However, diabatic CAES (D-CAES) systems, despite their commercial deployment, face limitations due to reliance on combustion, contributing to environmental pollution. Liquid-based DAC (L-DAC) systems offer negative emissions but are energy-intensive, often depending on electricity from natural gas plants. This study introduces an integrated system where L-DAC captures CO2 emitted by D-CAES during discharge, using electricity directly supplied by D-CAES, thus addressing energy and environmental concerns.

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Peer-reviewed Publications

Huang et al. (2025): Phase Change-Mediated Capture of Carbon Dioxide from Air with a Molecular Triamine Network Solid

Adrian J. Huang, Ankur K. Gupta, Henry Z. H. Jiang, Hao Zhuang, Malia B. Wenny Ryan A. Klein, Hyunchul Kwon, Katie R. Meihaus, Hiroyasu Furukawa, Craig M. Brown, Jeffrey A. Reimer, Wibe A. de Jong, Jeffrey R. Long IN: Journal of the American Chemical Society, https://doi.org/10.1021/jacs.4c18643

The recent discovery that diamine-appended metal–organic frameworks can exhibit cooperative CO2 uptake via the formation of ammonium carbamate chains begs the question of whether simple organic polyamine molecules could be designed to achieve a similar switch-like behavior with even higher separation capacities. Here, the authors present a solid molecular triamine, 1,3,5-tris(aminomethyl)benzene (TriH), that rapidly captures large quantities of CO2 upon exposure to humid air to form the porous, crystalline, ammonium carbamate network solid TriH(CO2)1.5·xH2O (TriHCO2). The phase transition behavior of TriH converting to TriHCO2 was studied through powder and single-crystal X-ray diffraction analysis, and additional spectroscopic techniques further verified the formation of ammonium carbamate species upon exposing TriH to humid air.

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Peer-reviewed Publications

Sun et al. (2025): Efficient and stable direct air capture with amine-functionalized MIL-100(Cr) metal-organic framework

Mengru Sun, Meng Zhao, Leyu Zhao, Qiang Wang, Jinzhu Ma, Hong He  IN: Environmental Functional Materials, https://doi.org/10.1016/j.efmat.2025.02.003

Amine-functionalized MOFs significantly enhance CO2 adsorption, yet most studies focus on adsorption capacity, with limited research on the impacts of water vapor and oxidative stability in practical DAC applications. Herein, MIL-100(Cr) was modified with polyethyleneimine (PEI), tetraethylenepentamine (TEPA), and diethanolamine (DEA) via impregnation, and their CO2 capture performance under DAC conditions was systematically evaluated, including adsorption capacity, cyclic stability, water resistance, and oxidative stability.

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Peer-reviewed Publications

Siebert et al. (2025): Meeting Carbon Dioxide Removal Demand in 2030: The Potential of Macroalgae Cultivation and Harvest

Lotta Siebert, Jiajun Wu, Lena-Katharina Bednarz, David Keller, Felix Meier, Christine Merk, Sonja Peterson, Wilfried Rickels IN: Journal of Ocean and Coastal Economics, https://doi.org/10.15351/2373-8456.1203

The authors derive estimates of countries’ hypothetical demand for CDR in 2030 based on their emissions reduction targets under the Paris Agreement. The aggregated average global demand for CDR in the compliance year 2030 is 1064 MtCO2, 353 MtCO2, and 124 MtCO2 for the low, medium, and high-cost CDR scenarios, respectively. This demand comes exclusively from countries and regions with relatively high GDP per capita, relatively high abatement costs and a limited supply of removals from afforestation. In a scenario with full international emissions trading, CDR demand until 2030 would drop to zero. Marine CDR methods such as macroalgae cultivation and harvesting could make a small but relevant contribution to meeting this demand. However, given the lead time required to achieve reasonable carbon sequestration efficiencies, a forward-looking climate policy would begin to incentivize and develop such methods now, so that areas within countries’ exclusive economic zones can be developed for this purpose.

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Peer-reviewed Publications

Mendes et al. (2025): Novel Field Experiment on Alkalinity Enhancement in Intertidal Environments—A Trailblazer for Natural Climate Solutions

I. Mendes, J. Lübbers, J. Schönfeld, A. Baldermann, A. R. Carrasco, A. Cravo, A. Gomes, P. Grasse, F. M. Stamm IN: JGR Biogeosciences, https://doi.org/10.1029/2024JG008591

A novel in situ experiment was designed and installed in a salt marsh at Ria Formosa coastal lagoon, southern Portugal. The experiment comprised deployments of different sizes of olivine and basalt substrates, and a control site, which were tidally submerged twice a day. A monthly monitoring scheme of supernatant and porewater properties from each deployment and control site was established, and procedures for temperature, salinity, oxygen, pH, total alkalinity, nutrient, and trace metal analyses were defined. This paper is devoted to the methods and describes the design, a protocol for the analyses, and an evaluation of experimental performance and reliability. Data from the first 6 months are presented for validation of the experiment.

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Peer-reviewed Publications

Zheng et al. (2025): In-situ amine modification of porous polymer/silica spiral wound module for CO2 capture from ambient air

Rongrong Zheng, Mengyao Jiang, Yanfang Fan IN: Chemical Engineering Journal, https://doi.org/10.1016/j.cej.2025.161078

Herein, the authors demonstrate a flexible membrane solid amine adsorbent based on cellulose acetate/silica composite supports that is fabricated into a spiral wound module functioning as a gas–solid contactor, presenting reduced pressure drop and comparable adsorption capacities with powdery solid amine materials. First, the phase inversion method is utilized to prepare cellulose acetate/silica membrane support, where the doping amount of silic varies from 60 wt% to 80 wt%. After assembling the support into a spiral module, poly (ethyleneimine) (PEI) is loaded in the module via an in-situ amine impregnation method, that the amine solution flows into the module which could reduce the support mass loss encountered in the conventional static impregnation method.

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Peer-reviewed Publications

Jung et al. (2025): Exploring the impact of hourly variability of air condition on the efficiency of direct air capture

Howoun Jung, Kyunam Kim, Jinhong Jeong, Aqil Jamal, Dong-Yeun Koh, Jay H. Lee IN: Chemical Engineering Journal, https://doi.org/10.1016/j.cej.2025.160840

This study delves into the impact of such environmental variations, focusing specifically on the energy consumption and productivity of DAC processes under daily and hourly fluctuating air conditions. Dynamic simulations coupled with the optimization of operating parameters were employed to investigate these effects. Bayesian optimization was utilized to refine the parameters for optimal DAC performance efficiently. 

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Peer-reviewed Publications

Nature – Shindell et al. (2025): Preserving carbon dioxide removal to serve critical needs

Drew Shindell, Joeri Rogelj IN: Nature CLimate Change, 2025, https://doi.org/10.1038/s41558-025-02251-y

Land-based CDR, which is the most widely deployed currently and in future projections, requires extensive land and water. Here the authors examine least-cost 1.5 °C overshoot pathways, finding that 78 of 81 scenarios would require all available sustainable CDR to compensate for H2A emissions and overshoot.

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