Enhancing Carbonate Weathering Using an Open-System Reactor: Tests Result in 20% Carbon Capture, but Low Cost Suggests Applicability

     Enhanced rock weathering is widely recognized as a viable land-based carbon sequestration solution. It works by accelerating the natural reaction between gases such as CO2, water, and common minerals. It can also be used to sequester carbon in oceans, utilizing seawater. Laboratory research in Israel is aiming to enhance the process to be more effective and efficient in sequestering carbon. Some important factors for optimizing enhanced rock weathering were found to be the size of the rock and mineral grains and how quickly and how heavily the CO2 is introduced and recirculated into the system. The study, published in Environmental Science & Technology, details the optimization of the process by controlling physicochemical parameters. According to Techno-Science:

“The system demonstrated its ability to convert approximately 20% of the injected CO₂ into dissolved inorganic carbon. This margin indicates significant potential for optimization through engineering. Dolomite proved to be a particularly interesting material, as it appears to avoid the formation of secondary precipitates that could re-release carbon, thus offering a more stable sequestration pathway.”

     The process could be used to capture and sequester a portion of flue gases from fossil fuel power plants in coastal regions. The process requires a source of CO2, rocks, and seawater. Although the process captures much less CO2 than mainstream CO2 capture, it is much less energy-intensive, which could make it financially viable for some projects, in comparison. The carbon is stored in the ocean as inorganic carbon in the form of carbonate and bicarbonate ions.

     The experiments utilized an ‘open-system benchtop reactor’ that would need to be re-engineered into a larger version. Carbonate rocks were continuously flushed with CO2 and seawater.

“A CO2 gas-to-seawater flux ratio of 10–20 was found to be most efficient for enhanced weathering. Only 20% of introduced CO2 was successfully utilized for carbonate weathering, indicating that efficiency improvements are needed.”

     Dolomite offered similar efficiency to calcite, without any reprecipitation, and thus, would be the preferred carbonate rock to utilize in the process.

 

      Below, it is shown how the dissolved inorganic carbon (DIC) was calibrated and measured. 

References:

 

From millennia to a few hours: they accelerate a carbon capture process. Cédric Depond. Techno Science. December 17, 2025. 🌊 From millennia to a few hours: they accelerate a carbon capture process

Maximizing Carbonate Weathering Rates in an Open-System Benchtop Reactor as a Means of CO2 Capture. Noga Moran, Eyal Wurgaft and Yonaton Goldsmith. Environmental Science & Technology. December 8, 2025. Maximizing Carbonate Weathering Rates in an Open-System Benchtop Reactor as a Means of CO2 Capture | Environmental Science & Technology