This week’s publication highlights relate to direct air capture, marine carbon removal, enhanced rock weathering, biochar and forestation.
A Bird’s Eye View of Recent Advances in Direct Air Capture of CO2 using MOFs
Abstract
Direct air capture (DAC) is a significant technology to combat climate change by extracting CO2 from the ambient air. Metal-organic frameworks (MOFs) play a crucial role in DAC applications utilizing adsorption and membrane technologies, although they have not yet entered the commercial market. Their notable characteristics, such as a strong affinity towards acidic gases, and exceptional features like high surface area, structural stability, flexible pore dimension, and crystalline nature, make them highly attractive. This comprehensive review covers various topics, including diverse synthesis methods, performance evaluations of different MOFs employed in DAC, a detailed comparison of various MOFs in DAC applications, reactor-contactor designs, kinetic mechanisms, thermodynamic modeling, technology roadmap, commercialization challenges, cost analysis, and future directions have been discussed. Each section delves into trends, future challenges, and prospects summarized in a table format. Solvothermal synthesis has been identified as an efficient method, surpassing microwave-assisted and ultrasound techniques, producing satisfactory crystallinity results. Notably, fixed-bed and rotating packed-bed reactors are the most effective for capturing CO2. Isotherm studies reveal the nature of adsorption, while kinetics studies assess the rate-limiting step, and thermodynamics evaluation confirms the feasibility and spontaneity of the process. Adsorption mechanisms such as surface modification and open metal sites significantly enhance the capture capacity. Factors like crystallinity, moisture affinity, and active sites are pivotal in selecting suitable MOFs. Additionally, commercial challenges and economic factors must be considered for effective large-scale deployment of MOFs in carbon capture applications.
Velagala, S. et al. (2026) A Bird’s Eye View of Recent Advances in Direct Air Capture of CO2 using MOFs 405 (136525) Fuel.
Read the full paper here: A Bird’s Eye View of Recent Advances in Direct Air Capture of CO2 using MOFs I Fuel.
Safety and Reliability Improvement in Hazardous Direct Air Capture (DAC) Plants through Failure Analysis and Prevention: A Review
Abstract
This review examines the safety, reliability, and failure mechanisms associated with hazardous Direct Air Capture (DAC) plants through a systematic synthesis of existing research, industrial experience, and lessons learned from related high-risk sectors such as carbon capture, oil and gas, and chemical processing. DAC systems handle corrosive chemicals, high temperatures, pressurized equipment, and complex mechanical subsystems, yet the literature lacks a consolidated engineering review of their failure modes and prevention strategies. This article compiles and categorizes the major mechanical, process, and human-factor failures that can occur across DAC units, including absorber columns, fans, blowers, valves, piping networks, rotating equipment, and thermal regeneration systems. Special attention is given to corrosion, degradation, fire and explosion hazards, and potential loss-of-containment scenarios involving hazardous solvents. The review also summarizes methods for hazard identification, operational risk reduction, and engineering controls applicable to DAC facilities. Finally, key gaps in the current knowledge base are identified to support future research and safe large-scale deployment of DAC.
Sotoodeh, K. (2026) Safety and Reliability Improvement in Hazardous Direct Air Capture (DAC) Plants through Failure Analysis and Prevention: A Review 8 (1) Safety in Extreme Environments.
Read the full paper here: Safety and Reliability Improvement in Hazardous Direct Air Capture (DAC) Plants through Failure Analysis and Prevention: A Review I Safety in Extreme Environments.
The Verification Challenge of Marine Carbon Dioxide Removal
Abstract
It is increasingly obvious that, even when reaching net-zero emissions, removal of anthropogenic CO2 from the atmosphere will be required. Some ocean-based removal technologies, while not proven for routine operation at scale, show promise. All of these rely on inducing a flux of CO2 from the atmosphere into the ocean that is directly attributable to the removal intervention. Crucial for the economic viability of these technologies is the quantification of the cumulative net air–sea flux of CO2 that an intervention can verifiably deliver. Because this flux is the difference between a realistic case with and a hypothetical case without intervention, it cannot be determined by observation alone—one must rely on a combination of informative observations and skillful models. Major uncertainties in the quantification of net CO2 uptake include the removal of seawater with a dissolved inorganic carbon deficit from direct contact with the atmosphere and the inevitable rebalancing of carbon among Earth’s mobile carbon pools.
Fennel, K. (2026) The Verification Challenge of Marine Carbon Dioxide Removal 18 Annual Review of Marine Science.
Read the full paper here: The Verification Challenge of Marine Carbon Dioxide Removal I Annual Review of Marine Science.
Enhanced Weathering and Biochar Co-deployment Boosts CO2 Sequestration through Changing Soil Properties
Abstract
Enhanced rock weathering (ERW) and biochar are potentially effective and scalable options for large-scale carbon dioxide removal (CDR), required to limit global temperature rise to 1.5 °C. Here we present experimental data on their co-deployment, an urgent and novel research direction that may render even larger CDR on multiple timescales. Two greenhouse pot experiments were conducted growing maize (Zea mays L) on sandy and clayey soils mixed with various doses of crushed dunite rocks (20–220 t ha−1) and a fixed dose of biochar (20 t ha−1) for two months. Furthermore, through a comparison of multiple soil extraction procedures for mass balance construction, our work supports the development of a standardized quantification method for CDR associated with ERW. Based on these elemental mass balances, dunite weathering was found to sequester between 1.06 ± 0.025 and 3.48 ± 0.084 t CO2 ha−1 in sandy soils and between 0.28 ± 0.015 and 1.60 ± 0.051 t CO2 ha−1 in clayey soils, while biochar co-deployment only slightly enhanced dunite weathering in the latter. Soil respiration also significantly increased on both soils, exceeding the achieved inorganic CO2 sequestration in our short-term experiments. However, we observed significant increases in soil pH and amorphous iron (hydr)oxide minerals, the latter known to be important for long-term organic carbon stabilization. We argue that the reduction in soil carbon due to enhanced soil respiration is only short term and is likely compensated for by the promising potential of ERW and biochar combinations for long-term inorganic carbon sequestration and organic carbon stabilization. The observed effects of ERW and biochar co-deployment on soil chemical properties, most notably increases in reactive (hydr)oxide minerals and soil pH, provide a great opportunity to boost CDR, with important differences between soil types.
Pas,E. al. (2026) Enhanced Weathering and Biochar Co-deployment Boosts CO2 Sequestration through Changing Soil Properties 466 (117668) Geoderma
Read the full paper here: Enhanced Weathering and Biochar Co-deployment Boosts CO2 Sequestration through Changing Soil Properties I Geoderma
A Machine Learning Framework to Assess Global Mangrove Forestation Potential under Current and Future Climate Scenarios
Abstract
Mangrove forestation is one of the most efficient forestry practices for carbon sequestration. This study developed a machine learning framework that integrated the random forest algorithm, SHapley Additive exPlanations (SHAP), and partial dependence plots (PDP) to assess global mangrove cover potential and its drivers, utilizing a suite of 48 environmental layers encompassing climatic, topographic, soil, and marine characteristics. Based on the mangrove cover potential, this study quantified the mangrove forestation potential under socioeconomic and ecological land-use constraints, as well as the carbon storage potential of forestation potential. The result showed that there is 156,682 km2 of mangrove forestation potential under current climate conditions. When assessing the distribution of mangrove forestation potential across Marine Ecoregions of the World (MEOW) provinces, MEOW ecoregions, and countries, the greatest forestation capacity is observed in the Tropical Northwestern Atlantic, Amazonia, and Indonesia. SHAP and PDP results revealed that soil saturated water content and distance to sea are the key factors controlling mangrove cover potential. Under contrasting shared socioeconomic paths (SSP1-2.6 and SSP5-8.5), mangrove cover potential shows a general increase due to climate changes. However, under SSP5-8.5, sea-level rise alone could reduce the current forestation potential by 26,820 km2. Furthermore, only 19,361 km2 of the current forestation potential coincides with areas where future cover potential is projected to increase across both scenarios, indicating that the synergistic enhancement effect brought about by climate change on the forestation results is limited. From a national perspective, the five countries with the highest carbon storage potential from mangrove forestation are Indonesia, Brazil, Australia, Mexico, and the Philippines, with 1.016, 0.514, 0.409, 0.391, and 0.317 GtC, respectively. The global mangrove forestation potential map with clear spatial granularity provided in this study can offer important support for international-scale mangrove forestation.
Li, G. et al. (2026) A Machine Learning Framework to Assess Global Mangrove Forestation Potential under Current and Future Climate Scenarios 295 (123923) Environmental Research.
Read the full paper here: A Machine Learning Framework to Assess Global Mangrove Forestation Potential under Current and Future Climate Scenarios I Environmental Research.