This week’s publication highlights cover a wide range of issues pertaining to direct air capture, afforestation, carbon mineralization, biomass CDR and enhanced weathering.
Exploring the Impact of Hourly Variability of Air Condition on the Efficiency of Direct Air Capture
Abstract
Direct Air Capture (DAC) is increasingly acknowledged as a pivotal technology for combating climate change and advancing global decarbonization initiatives. By actively removing CO2 from the atmosphere, DAC offers a scalable approach to manage residual emissions and attain net-zero carbon goals, augmenting existing mitigation strategies. Nevertheless, the efficacy of DAC is considerably influenced by environmental conditions such as ambient temperature and humidity, which can significantly affect its operational performance. 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. The study evaluated cyclic DAC operations employing Temperature-Vacuum-Swing Adsorption (TVSA) across four diverse climatic zones—hot/dry, hot/humid, cold/dry, and cold/humid, during both winter and summer seasons. Results indicate that high humidity levels detrimentally impact DAC efficiency by increasing the heat required for H2O desorption, the work of pumps, and the duration of desorption processes, which escalates energy use and diminishes productivity. Furthermore, hourly fluctuations in air conditions significantly degraded DAC performance, resulting in up to a 35.9% increase in energy consumption and a 22.2% reduction in productivity compared to monthly-averaged air conditions with constant values. Re-optimizing the operating parameters to account for variations in ambient air resulted in approximately a 5% improvement in both energy consumption and productivity. These enhancements could be further optimized through the implementation of advanced control systems that dynamically adjust operating parameters for each cycle based on forecasted air conditions. The findings help bridge the gap between predicted performance and actual operational outcomes, supporting the strategic deployment of scaled-up DAC processes to achieve optimal economic outcomes.
Jung, H. et al. (2025) Exploring the Impact of Hourly Variability of Air Condition on the Efficiency of Direct Air Capture 508 (160840) Chemical Engineering Journal.
Read the full paper here: Exploring the Impact of Hourly Variability of Air Condition on the Efficiency of Direct Air Capture I Chemical Engineering Journal.
Incorporating Site Suitability and Carbon Sequestration of Tree Species into China’s Climate-Adaptive Forestation
Abstract
Strategic selection and precise matching of climate-resilient tree species are crucial for maximizing the mitigation and adaptation potential of Climate-Smart Forestry. However, current forestation plans often overlook species-specific environmental shifts, leading to suboptimal long-term carbon sequestration. Here we developed a climate-adaptive optimization framework to guide tree species selection and planting in China, based on projected habitat suitability and range shifts under future climate scenarios. Utilizing over 200,000 tree records from China’s National Forest Inventory (1999–2018), we quantified habitat suitability declines of 12.1%–42.9% for currently dominant plantation species by 2060 due to climate change. By optimizing species-site matching and strategically harvesting timber at peak carbon uptake, we identified 43.2 million hectares suitable for climate-resilient forestation between 2025 and 2060, enabling the planting of approximately 46 billion climate-adapted trees with a total sequestration potential of 3822.6 Tg of carbon—a 28.7% increase compared to unmanaged scenarios. Our study highlights the importance of optimizing adaptive forestation strategies to enhance carbon sequestration under future climate conditions, providing technical guidance for climate-resilient forest management in support of China’s net-zero commitment.
Zhang, M. et al. (2025) Incorporating Site Suitability and Carbon Sequestration of Tree Species into China’s Climate-Adaptive Forestation. Science Bulletin
Read the full paper here: Incorporating Site Suitability and Carbon Sequestration of Tree Species into China’s Climate-Adaptive Forestation I Science Bulletin.
A Study of Ex-Situ Carbon Mineralization under Low Intensity Aqueous Reaction
Abstract
Safe, scalable and permanent options for carbon dioxide storage is essential to achieve net negative greenhouse gas emissions and limit catastrophic global warming. A benign and thermodynamically stable form of CO2 storage is a carbonate mineral. This work examined ex situ carbon mineralization of magnesium rich ultramafic and mafic rocks under previously unstudied low intensity aqueous reaction conditions (T = 25 °C, PCO2 = 80 kPa, pH = 7). Carbonate reaction extents, dissolved metals and formed carbonate phases were evaluated in experiments ranging from days to months using thermogravimetric and evolved gas analysis, dissolved elemental analysis, BET surface area, and semi-quantitative powder x-ray diffraction methods. Reaction kinetics were similar across both mineral types, with 12 % reaction extent achieved in under ten weeks. After 160 days of low intensity reaction, the ultramafic xenolith trapped 9 ± 2 wt% CO2. After 64 days of reaction, a scoriaceous picrite basalt trapped 7 ± 3 wt% CO2. Primarily amorphous magnesium carbonate was formed, with partial conversion to magnesite upon oven drying. The CO2 mineralization of abundant surface rocks under mild conditions offer potential for alternative mineralization strategies for permanent negative CO2 emissions.
Sjolund, A. et al. (2025) A Study of Ex-Situ Carbon Mineralization under Low Intensity Aqueous Reaction 15 (100391) Carbon Capture Science & Technology.
Read the full paper here: A Study of Ex-Situ Carbon Mineralization under Low Intensity Aqueous Reaction I Carbon Capture Science & Technology.
A Techno-economic Assessment of Carbon Dioxide Removal Pathways via Biochemical Conversion of Lignocellulose to Biofuels and Bioplastics
Abstract
Biomass carbon removal and storage (BiCRS) is a promising pathway to mitigate climate change via large scale removal of atmospheric carbon dioxide (CO2). We modeled several fermentation technologies, producing a variety of bioproducts from lignocellulosic feedstocks, to understand their levelized cost of CO2 removal under multiple scenarios. Lifecycle greenhouse gas (GHG) emissions are accounted to provide cradle-to-grave estimates of carbon intensity (CI). We did not account for the avoided fossil CO2 emissions from the use of biofuels in our CO2 removal cost calculations, because avoided emissions do not contribute to CO2 removal. The main products from the fermentation technologies we modeled include renewable diesel, ethanol, sustainable aviation fuel (SAF), and polyethylene (PE), with co-products including CO2, adipic acid, steam, and electricity. PE, depending on its end-of-life management, can serve as a form of biogenic carbon storage. PE has the potential to remove 1.2–1.5 tCO2 per dry t-biomass, whereas biofuels have the potential to remove 0.3–0.9 tCO2 per dry t-biomass, indicating that PE production is a more efficient method of carbon removal. We quantify costs of CO2 removal to be $60 – $675 per metric tCO2 removed across the various fermentation pathways. Under the scenarios analyzed, bioplastic production from lignocellulosic biomass is a more cost-effective route to CO2 removal than biofuel production, with costs of CO2 removal via bioplastics being 50–90 % lower than that of biofuels. Future research should explore the potential benefits and drawbacks of expanding bioplastic production for large-scale CO2 removal.
Clauser, N. (2025) A Techno-economic Assessment of Carbon Dioxide Removal Pathways via Biochemical Conversion of Lignocellulose to Biofuels and Bioplastics 216 (115714) Renewable and Sustainable Energy Reviews.
Read the full paper here: A Techno-economic Assessment of Carbon Dioxide Removal Pathways via Biochemical Conversion of Lignocellulose to Biofuels and Bioplastics I Renewable and Sustainable Energy Reviews.
Supplementing Enhanced Weathering with Organic Amendments Accelerates the Net Climate Benefit of Soil Amendments in Rangeland Soils
Abstract
Carbon dioxide (CO2) removal (carbon dioxide removal (CDR)) that combines decreased greenhouse gas emissions with atmospheric CO2 reduction is needed to limit climate change. Enhanced rock weathering (ERW) of ground silicate minerals is an emerging CDR technology with the potential to decrease atmospheric CO2. However, there are few multi-year field studies and considerable uncertainty in field-rates of ERW. We explored combining finely ground metabasaltic rock with other soil CDR technologies (compost and biochar amendments) to stimulate carbon (C) sequestration. The combined ground rock (GR), compost, and biochar amendment had the greatest increases in soil C stocks over 3 years (15.3 ± 4.8 Mg C ha−1). All other treatments slowed or reversed background C losses, with GR-only treatments reducing rates of soil C loss relative to the control but still losing soil C over time. Ground rock amendments lowered nitrous oxide (N2O) emissions by 11.0 ± 0.6 kg CO2e ha−1 yr−1 and increased methane (CH4) consumption by 9.5 ± 3.5 to 18.4 ± 4.4 kg CO2e ha−1 yr−1; while noteworthy, emissions reductions were an order of magnitude smaller than organic C sequestration with compost amendments. The combined amendment yielded the greatest estimated net ecosystem benefit (3 year relative changes in soil C, estimated ERW rates, and greenhouse gas emissions) of −86.0 ± 24.7 Mg CO2e ha−1. Benefits were dominated by soil organic C gains, directly from organic amendments and indirectly from increased plant growth. Weathering rates were <10% of the theoretical potential. Combined ERW and organic amendments increased estimated weathering rates and stimulated soil organic C sequestration.
Anthony, T. et al. (2025) Supplementing Enhanced Weathering with Organic Amendments Accelerates the Net Climate Benefit of Soil Amendments in Rangeland Soils. 6 (2) Advancing Earth and Space Sciences.
Read the full paper here: Supplementing Enhanced Weathering with Organic Amendments Accelerates the Net Climate Benefit of Soil Amendments in Rangeland Soils I Advancing Earth and Space Sciences.