A new process could enable crushed rocks to capture carbon dioxide from the air more quickly, speeding up a climate removal technique. Researchers at Stanford University have developed a way to produce reactive minerals that can increase the weathering rate of natural silicates. By converting these minerals into calcium silicate and magnesium oxide, they can speed up the reaction by thousands of times.
The process uses kilns heated to 1400°C, requiring natural gas for energy. However, the researchers suggest capturing emissions at source or offsetting them with on-site use of the reactive minerals. Once production costs are accounted for, one tonne of reactive material removes about 1 tonne of carbon dioxide from the atmosphere.
The team’s proposal has sparked debate among experts. While some welcome accelerated weathering rates, others raise concerns about scaling up production and deployment. The new process may produce cement-like minerals that could be used in agriculture, but more research is needed to understand its viability.
Experts at the University of Southampton and Heriot-Watt University have weighed in on the proposal. Rachael James at the University of Southampton sees the potential for accelerated weathering rates as beneficial, while Phil Renforth at Heriot-Watt University cautions that further research is necessary to determine its feasibility.
Source: https://www.newscientist.com/article/2469148-clever-chemistry-can-make-rocks-absorb-co2-much-more-quickly