Unlocking the Potential of Bioenergy with Carbon Capture and Sequestrations in Africa
Abstract
The Intergovernmental Panel on Climate Change has highlighted the need for technologies that can remove greenhouse gases from the atmosphere to meet the targets of the Paris Agreement. Bioenergy with Carbon Capture and Sequestrations (BECCS) is one such technology for mitigating climate change by enabling negative carbon emissions. Despite Africa’s vast bioenergy potential, the continent has yet to fully explore and develop a BECCS market. This review paper provides a comprehensive overview of BECCS technology, the role of BECCS in sustainable development, mitigating climate change, national policies, prospects, challenges, and pathways for developing a BECCS market in Africa. It discusses the technical, economic, and policy dimensions of BECCS, identifies the key biomass resources available in
Africa, and explores strategies for overcoming barriers to implementation. The review concludes with recommendations for fostering a sustainable BECCS market in Africa that aligns with the continent’s development goals and bioenergy policy.
Uzoagba, C. and Onwualu, A. (2025) Unlocking the Potential of Bioenergy with Carbon Capture and Sequestrations in Africa. Cureus Journal of Engineering.
Read the full article: Unlocking the Potential of Bioenergy with Carbon Capture and Sequestrations in Africa I Cureus Journal of Engineering.
Protect Young Secondary Forests for Optimum Carbon Removal:
Abstract
Avoiding severe global warming requires large-scale removals of atmospheric carbon dioxide. Forest regeneration offers cost-effective carbon removals, but annual rates vary substantially by location and forest age. Here we generate grid-level (~1-km2) growth curves for aboveground live carbon in naturally regrowing forests by combining 109,708 field estimates with 66 environmental covariates. Across the globe and the first 100 years of growth, maximum carbon removal rates varied 200-fold, with the greatest rates estimated in ~20- to 40-year-old forests. Despite a focus on new forests for natural climate solutions, protecting existing young secondary forests can provide up to 8-fold more carbon removal per hectare than new regrowth. These maps could help to target the optimal ages and locations where a key carbon removal strategy could be applied, and improve estimates of how secondary forests contribute to global carbon cycling.
Robinson, N. et al. (2025) Protect Young Secondary Forests for Optimum Carbon Removal 15 Nature Climate Change 793-800.
Read the full article: Protect Young Secondary Forests for Optimum Carbon Removal I Nature Climate Change.
Removal of Atmospheric Pollutants Using Biochar: Preparation, Application, Regeneration and Its Future Research
Abstract
Air quality management is critical for achieving Sustainable Development Goal 3. Pollutants such as VOCs, NOx, and particulate matter contribute to over 3 million premature deaths each year. Annually, 140 Gt of biomass waste is produced mainly in the EU, Brazil, the USA, India, and China, with crop residue burning contributing to 18% of global CO₂ emissions and releasing harmful pollutants like PM and VOCs. This review highlights biochar as a viable solution for air pollution remediation, showcasing its strong adsorption capabilities for gases like CO₂ and NOx. Biochar can be produced from agricultural waste using methods such as pyrolysis as well as gasification and hydrothermal carbonization. These production methods create biochar with specific physicochemical properties that vary based on the type of feedstock used and the processing conditions. Activation techniques enhance adsorption capacity, achieving an 86% microporous structure with a surface area of 151 m2/g, with eucalyptus-activated biochar showing a 99.76% pollutant removal efficiency. Biochar has shown significant removal capabilities for various air pollutants, with miscanthus capturing MEK at 2.5 to 43 mg/g, bamboo-activated biochar achieving 89.19% removal of PM2.5, and rice husk biochar demonstrating a 95.7 mg/g capacity for NO and 100.181 mg/g for SO₂. Indoor pollution mitigation is enhanced as micro-gasification cookstoves reduce CO, CO₂, and PM2.5 emissions by 79%, while finer biochar particles achieve 6% to 75% removal for VOCs like formaldehyde. Its porous structure allows for effective pollutant adsorption via physisorption and chemisorption. Reactivation methods, both thermal and non-thermal, enhance its adsorption capacity while preserving its integrity. Despite its benefits for air quality and carbon sequestration, biochar faces challenges, including greenhouse gas emissions during production and costly regeneration. However, converting biomass to biochar could sequester 0.3 to 2 Gt of CO₂ annually by 2050, supporting carbon market initiatives and circular economy goals.
Verma, N. and Devi, N. (2025) Removal of Atmospheric Pollutants Using Biochar: Preparation, Application, Regeneration and Its Future Research. 18 Air Quality, Atmosphere & Health 1205-1244.
Read the full paper here: Removal of Atmospheric Pollutants Using Biochar: Preparation, Application, Regeneration and Its Future Research I Air Quality, Atmosphere & Health.
Enhanced CO2 Removal and Improved Carbon Budget by Enhanced Rock Weathering: A Field Experiment in Hokkaido, Japan
Abstract
Climate change affects food production, increasing the need for CO2 removal (CDR) strategies. Enhanced rock weathering, which involves the spreading of crushed silicate rock powder on agricultural soil to sequester atmospheric CO2 via enhanced natural weathering, shows potential to enrich the agricultural soil. In this study, we evaluated the short-term impacts of basalt powder on CO2 emissions in rhizosphere and non-rhizosphere soils and estimated the field carbon budget in an experimental soybean field at Hokkaido University, Japan. Basalt powder application at 150 Mg ha−1, with incorporation into the soil to a depth of 15 cm, significantly increased the soil pH and reduced the soil volumetric water content. Regardless of treatment, the carbon budget was negative, indicating the overall carbon loss in field. Basalt powder application reduced this carbon loss from 2.69 ± 0.41 to 1.90 ± 0.73 Mg C ha−1, primarily by absorbing CO2 that would otherwise have been released into the atmosphere through weathering and sequestering it in the soil, though the difference was not significant. ERW-induced CO2 emission reduction rate was 0.81 ± 0.17 Mg C ha−1, with approximately 86.4% attributed to rhizosphere soil. In the rhizosphere, basalt application significantly reduced CO2 emissions, suggesting that root exudates may promote basalt weathering and increase stabilization of carbon in the rhizosphere through interactions with the rock powder, thereby contributing to the observed emission reduction. These findings indicate that basalt application can significantly reduce CO2 emissions from agricultural soils, particularly in the rhizosphere, and could potentially improve the overall farmland carbon balance. However, further research is necessary to explore the long-term effects of ERW on soil carbon dynamics and elucidate the differential responses of soil organic and inorganic carbon pools, especially considering that the applied basalt powder is unlikely to completely weather within a single year, and thus its CO2 removal effects may persist over multiple growing seasons.
Yang, Y. et al. (2025) Enhanced CO2 Removal and Improved Carbon Budget by Enhanced Rock Weathering: A Field Experiment in Hokkaido, Japan. Nutrient Cycling in Agroecosystems.
Read the full paper here: Enhanced CO2 Removal and Improved Carbon Budget by Enhanced Rock Weathering: A Field Experiment in Hokkaido, Japan I Nutrient Cycling in Agroecosystems.
Near-Cryogenic Direct Air Capture Using Adsorbents
Abstract
Direct air capture (DAC) of CO2 is a key component in the portfolio of negative emissions technologies for mitigating global warming. However, even with the most potent amine sorbents, large-scale DAC deployment remains limited by high energy and capital costs. Recently, adsorbents relying on weak interactions with CO2 have emerged as a potential alternative, thanks to their rapid adsorption kinetics and superior long-term stability, particularly under sub-ambient conditions (∼253 K). Despite these advantages, their use is hindered by the need for a water-removal process, location-specific constraints, and insufficient working capacity even in cold climates. In this study, we hypothesized that further reducing the adsorption temperature to a near-cryogenic range (160–220 K) could enable cost-effective DAC by utilizing the full potential of physisorbents. We primarily consider integrating DAC with a relatively untapped source of cold energy—liquified natural gas (LNG) regasification—to perform near-cryogenic DAC. From large-scale molecular simulations, Zeolite 13X and CALF-20 were identified as promising candidates. These materials were subsequently examined through experiments, including breakthrough analyses at 195 K. Their high CO2 sorption capacity (4.5–5.5 mmol g−1), combined with a low desorption enthalpy and robust long-term stability, led to a threefold reduction in the levelized cost of capture (down to 68.2 USD per tonne CO2). Estimates of the global LNG regasification resource suggest that LNG–DAC coupling could potentially enable the capture of 103–142 megatonnes of CO2 annually as of 2050.
Kim, S. et al. (2025) Near-Cryogenic Direct Air Capture Using Adsorbents. Energy & Environmental Science.
Read the full paper here: Near-Cryogenic Direct Air Capture Using Adsorbents I Energy & Environmental Science.