This week’s publication highlights cover a wide range of issues in relation to direct air capture, carbon mineralization, enhanced rock weathering, ocean alkalinity enhancement and bioenergy with carbon capture and storage.
Perspective on Distributed Direct Air Capture: What, Why, and How?
Abstract
Direct air capture (DAC) is widely considered as a critical negative emission technology to not only mitigate but reverse global climate change. While commercially expanding, its efficiency is limited by energy-intensive sorbent regeneration. Here, we highlight distributed DAC as a complement to centralized systems, analyzing the regeneration energy demands and carbon footprints of various sorbents. A comprehensive evaluation of distributed DAC’s impact is crucial for maximizing its potential.
Chen, Y. et al. (2025) Perspective on Distributed Direct Air Capture: What, Why, and How? 12 (3) Nature.
Read the full paper here: Perspective on Distributed Direct Air Capture: What, Why, and How? I Nature.
The Pre-Acidification Triggers and Enhances Carbon Mineralization in Dicalcium Silicate
Abstract
The mineral carbonation under the natural chemical weathering reaction is one of the significant geochemical processes. The underlying mineral carbonation reaction mechanism remains unclear on the electronic scale. This work illustrates how pre-acidification treatments create solvation structures that encourage carbon mineralization in β-C2S (100) and γ-C2S (010) by well-defined ab initio molecular dynamics and well-tempered metadynamics approaches. The results indicate that the HCO3−, generated during CO2 pre-acidification, exhibits distinct behavior on the β-C2S (100) and γ-C2S (010) surfaces, which directly affects the formation of carbonate complex. In the β-C2S (100)/H2O-HCO3−system, the HCO3− is dissociated by the surface O atoms (Os), which subsequently form carbonate complexes through interactions with adjacent H2O molecules and the surface Ca atoms. However, following HCO3− dissociation, the resulting CO32− interacts with adjacent H2O molecules to form a stable solvation structure on the γ-C2S (010) surface. This promotes the carbonation reaction in the γ-C2S (010)/H2O-HCO3−system. This work paves the way to understand the mechanism of mineral carbonation on the electronic scale and offers valuable insights into the process of geological evolution.
Li, N. et al. (2025) The Pre-Acidification Triggers and Enhances Carbon Mineralization in Dicalcium Silicate. Journal of the American Ceramic Society.
Read the full paper here: The Pre-Acidification Triggers and Enhances Carbon Mineralization in Dicalcium Silicate I Journal of the American Ceramic Society
Rethinking CO2 Removal Efficiency in Enhanced Rock Weathering
Abstract
Rising atmospheric temperatures predominantly stem from the accumulation of anthropogenically emitted carbon dioxide (CO2) and other greenhouse gases. The concept of CO2 removal (CDR) from the atmosphere is regarded as a critical complement to emission reductions aimed at limiting future global temperature increases to 1.5 °C by 2100, relative to preindustrial levels. Enhanced rock weathering (ERW) is a promising CDR strategy for mitigating global warming. This approach involves accelerating the dissolution of crushed silicate rocks, such as basalt, applied to croplands and forest soils to convert atmospheric CO2 into bicarbonate ions (HCO3–), which can subsequently be stored in groundwater and oceans for over 10,000 years. Operational activities (e.g., mining, crushing, and transporting silicate rocks) also emit CO2. But after deducting CO2 emissions from ERW deployment, it is estimated that ERW could sequester approximately two billion metric tons of CO2 annually if implemented across major agricultural regions worldwide. Furthermore, ERW offers additional cobenefits, including enhanced crop production, improved soil health, and reduced ocean acidification. However, ERW may also initiate a cascade of soil reactions, some of which have not received adequate attention or remain incompletely understood. Two critical considerations are particularly noteworthy: first, not all CO2 sequestered by ERW originates from the atmosphere; second, ERW may stimulate increased CO2 emissions from soil respiration and enhanced mineralization of soil organic carbon.
Li, C. et al. (2025) Rethinking CO2 Removal Efficiency in Enhanced Rock Weathering 59 (18) Environmental Science & Technology.
Read the full paper here: Rethinking CO2 Removal Efficiency in Enhanced Rock Weathering I Environmental Science & Technology.
Alkalinity Factory Can Achieve Positive Climate Benefits within Decades
Abstract
Ocean alkalinity enhancement is a thriving pathway for mitigating climate change. The alkalinity factory promises controllable environmental impacts and cost-effective monitoring, reporting, and verification. However, research gaps remain in the identification of the climate benefits of the alkalinity factory, and filling these gaps is essential for allocating human efforts toward mitigation. In this study, we employed a life cycle assessment approach to evaluate the climate contributions of several pre-configured alkalinity factories, and milled olivine was taken as a stable alkalinity source, named the marine alkalinity reinforcement system (MARS). The results indicate that the MARS can capture an average of 153.5 tons of CO2 over its lifespan, and a medium-sized (50 m3) MARS filled with 25 μm olivine can minimize carbon and total environmental footprints. In addition, the payback periods for these footprints range from 1.1 to 6.2 years and from 4.1 to 22.5 years, respectively, depending on the olivine-to-seawater ratio. The use of ultra-fine olivine (5 μm) and a high olivine-to-seawater ratio (4:1) significantly increased the carbon sequestration rate but also resulted in a high olivine comminution energy consumption and engineering challenges. Our findings reveal that the alkalinity factory is a viable solution in marine carbon dioxide removal when configurations can ensure positive environmental benefits.
Yan, Q. et al. (2025) Alkalinity Factory Can Achieve Positive Climate Benefits within Decades 504 (145406) Journal of Cleaner Production.
Read the full paper here: Alkalinity Factory Can Achieve Positive Climate Benefits within Decades I Journal of Cleaner Production.
Process Safety in Bioenergy with Carbon Capture and Storage Systems
Abstract
In response to the climate crisis, the United States has embarked on an ambitious program to achieve 100% carbon-free electricity generation by 2035 and net-zero greenhouse gas emissions by 2050. The implementation of bioenergy with carbon capture and storage (BECCS) systems is an essential component of that strategy. BECCS is broadly defined as the utilization of biomass energy (from the processing of solids, liquids, or vapors) with the capture of carbon dioxide and subsequent permanent storage in a deep geological formation. There are numerous potential technologies and flowsheets for implementing BECCS, and the supply chains rely upon support from the agricultural, forestry, and solid waste industries. Inherent in BECCS systems are the hazards associated with combustible dusts, spontaneous ignition and smoldering of combustible solids, flammable liquids, flammable vapors and gases, toxic gases, and more. For BECCS to be deployed commercially across the United States, it is imperative that process safety risks are controlled. A risk-based process safety (RBPS) program can help manage the risks of a BECCS facility and minimize process safety incidents. In this paper, we present two representative bioenergy technologies as mini-case studies to illustrate the range of process hazards encountered. Process safety strategies required by regulation are briefly reviewed and potential gaps are identified. We then demonstrate how RBPS can be implemented in a practical and effective manner to fill the gaps.
Ogle, R. et al. (2024) Process Safety in Bioenergy with Carbon Capture and Storage Systems 44 (1) Process Safety Progress.
Read the full paper here: Process Safety in Bioenergy with Carbon Capture and Storage Systems I Process Safety Progress.