Weekly CDR Publication Highlights (13 February 2025)
This week’s selected publications cover issues pertaining to direct air capture, bioenergy with carbon capture and storage and carbon removal with enhanced weathering.
Assessing the Net Carbon Removal Potential by a Combination of Direct Air Capture and Recycled Concrete Aggregates Carbonation
Abstract
Removing and storing CO2 from the atmosphere has an important role in combating climate change. This study assessed the CO2 removal potential of combining direct air capture with carbonation of recycled concrete aggregates (RCAs). An industrial-scale RCA carbonation process model quantified key parameters’ impacts on carbonation duration and energy consumption. Furthermore, a lifecycle analysis evaluated scenarios of two cases: (i) using pure CO2 with transportation between DAC and carbonation, and (ii) onsite production of low-purity CO2. For 90 % carbonation of 1 tonne of RCA, the performance of case-i scenarios ranged from ∼13 kg net CO2 removal to ∼14 kg net CO2 emission, influenced by DAC technology, transport option, and electricity carbon intensity. In case-ii scenarios, 1 % CO2 feed purity achieved 70 % greater CO2 removal than using pure CO2. This work provides an initial indication of the potential of this scheme while revealing key factors to investigate in future experimental exploration.
Chen, L. and Yang, A. (2025) Assessing the Net Carbon Removal Potential by a Combination of Direct Air Capture and Recycled Concrete Aggregates Carbonation. Resources, Conservation and Recycling 212 (107940).
Read the full paper here: Assessing the Net Carbon Removal Potential by a Combination of Direct Air Capture and Recycled Concrete Aggregates Carbonation I Resources, Conservation and Recycling.
—--------------------------------------------------------------------------------------------------------------
Direct Air Capture (DAC): Molten Carbonate Direct Transformation of Airborne CO2 to Durable, Useful Carbon Nanotubes and Nano-Onions
Abstract
This study introduces the concept and first demonstration of an effective molten carbonate chemistry for Direct Air Capture (DAC). Molten carbonate electrolysis is a high-temperature decarbonization process within Carbon Capture, Utilization and Storage (CCUS) that transforms chemistry transforming flue gas CO2 into carbon nanotubes and carbon nano-onions. The key challenge for molten carbonate DAC is to split air’s 0.04% CO2 without heating the remaining 99.6%. This is accomplished by integrating a diffusive, insulating membrane over an electrolyte with a high affinity for CO2.
Licht, G., Peltier, E., Gee, S. and Licht, S. (2025) Direct Air Capture (DAC): Molten Carbonate Direct Transformation of Airborne CO2 to Durable, Useful Carbon Nanotubes and Nano-Onions. RCS Sustainability.
Read the full paper here: Direct Air Capture (DAC): Molten Carbonate Direct Transformation of Airborne CO2 to Durable, Useful Carbon Nanotubes and Nano-Onions I RCS Sustainability.
—--------------------------------------------------------------------------------------------------------------
Expert Projections on the Development and Application of Bioenergy with Carbon Capture and Storage Technologies
Abstract
Bioenergy with carbon capture and storage (BECCS) is a crucial element in most modelling studies on emission pathways of the Intergovernmental Panel on Climate Change to limit global warming. BECCS can substitute fossil fuels in energy production and reduce CO2 emissions, while using biomass for energy production can have feedback effects on land use, agricultural and forest products markets, as well as biodiversity and water resources. To assess the former pros and cons of BECCS deployment, interdisciplinary model approaches require detailed estimates of technological information related to BECCS production technologies. Current estimates of the cost structure and capture potential of BECCS vary widely due to the absence of large-scale production. To obtain more precise estimates, a global online expert survey (N = 32) was conducted including questions on the regional development potential and biomass use of BECCS, as well as the future operating costs, capture potential, and scalability in different application sectors. In general, the experts consider the implementation of BECCS in Europe and North America to be very promising and regard BECCS application in the liquid biofuel industry and thermal power generation as very likely. The results show significant differences depending on whether the experts work in the Global North or the Global South. Thus, the findings underline the importance of including experts from the Global South in discussions on carbon dioxide removal methods. Regarding technical estimates, the operating costs of BECCS in thermal power generation were estimated in the range of 100–200 USD/tCO2, while the CO2 capture potential was estimated to be 50–200 MtCO2yr−1 by 2030, with cost-efficiency gains of 20% by 2050 due to technological progress. Whereas the individuals’ experts provided more precise estimates, the overall distribution of estimates reflected the wide range of estimates found in the literature. For the cost shares within BECCS, it was difficult to obtain consistent estimates. However, due to very few current alternative estimates, the results are an important step for modelling the production sector of BECCS in interdisciplinary models that analyse cross-dimensional trade-offs and long-term sustainability.
Heimann, T., Whaling, L., Honkomp, T., Delzeit, R., Pirrrone, A., Schier, F. and Delzeit, R. (2025) Expert Projections on the Development and Application of Bioenergy with Carbon Capture and Storage Technologies I Environmental Research Letters 20 (024059).
Read the full paper here: Expert Projections on the Development and Application of Bioenergy with Carbon Capture and Storage Technologies I Environmental Research Letters
—--------------------------------------------------------------------------------------------------------------
Architecting Metal-Organic Frameworks at Molecular Level toward Direct Air Capture
Abstract
Escalating carbon dioxide (CO2) emissions have intensified the greenhouse effect, posing a significant long-term threat to environmental sustainability. Direct air capture (DAC) has emerged as a promising approach to achieving a net-zero carbon future, which offers several practical advantages, such as independence from specific CO2 emission sources, economic feasibility, flexible deployment, and minimal risk of CO2 leakage. The design and optimization of DAC sorbents are crucial for accelerating industrial adoption. Metal–organic frameworks (MOFs), with high structural order and tunable pore sizes, present an ideal solution for achieving strong guest–host interactions under trace CO2 conditions. This perspective highlights recent advancements in using MOFs for DAC, examines the molecular-level effects of water vapor on trace CO2 capture, reviews data-driven computational screening methods to develop a molecularly programmable MOF platform for identifying optimal DAC sorbents, and discusses scale-up and cost of MOFs for DAC.
Ye, Z., Xie, Y., Kirklikovali, K., Xiang, S., Farha, O., Chen, B. (2025) Architecting Metal-Organic Frameworks at Molecular Level toward Direct Air Capture.
Read the full paper here: Architecting Metal-Organic Frameworks at Molecular Level toward Direct Air Capture I Journal of the American Chemical Society
—--------------------------------------------------------------------------------------------------------------
Transforming US Agriculture for Carbon Removal with Enhanced Weathering
Abstract
Enhanced weathering (EW) with agriculture uses crushed silicate rocks to drive carbon dioxide removal (CDR)1,2. If widely adopted on farmlands, it could help achieve net-zero emissions by 20502,3,4. Here we show, with a detailed US state-specific carbon cycle analysis constrained by resource provision, that EW deployed on agricultural land could sequester 0.16–0.30 GtCO2 yr−1 by 2050, rising to 0.25–0.49 GtCO2 yr−1 by 2070. Geochemical assessment of rivers and oceans suggests effective transport of dissolved products from EW from soils, offering CDR on intergenerational timescales. Our analysis further indicates that EW may temporarily help lower ground-level ozone and concentrations of secondary aerosols in agricultural regions. Geospatially mapped CDR costs show heterogeneity across the USA, reflecting a combination of cropland distance from basalt source regions, timing of EW deployment and evolving CDR rates. CDR costs are highest in the first two decades before declining to about US$100–150 tCO2−1 by 2050, including for states that contribute most to total national CDR. Although EW cannot be a substitute for emission reductions, our assessment strengthens the case for EW as an overlooked practical innovation for helping the USA meet net-zero 2050 goals5,6. Public awareness of EW and equity impacts of EW deployment across the USA require further exploration7,8 and we note that mobilizing an EW industry at the necessary scale could take decades.
Beerling, D. et al. (2025) Transforming US Agriculture for Carbon Removal with Enhanced Weathering. Nature. 638.
Read the full paper here: Transforming US agriculture for carbon removal with enhanced weathering I Nature.