Juerg M. Matter 1 , Joanna Speer 1, Christopher Day 2, Peter B. Kelemen 3, Amal Ibrahim4, Sulaiman Al Mani4, Ehab Tasfai 4, Moeez Ilyas4, Karan Khimji4 & Talal Hasan4

Extended abstract

The success of industrial scale carbon capture and storage in geologic reservoirs depends on the permanence of the stored carbon dioxide (CO2). Carbon dioxide capture and mineralisation (CCM) or mineral carbonation, which is the conversion of CO2 to carbonate minerals via fluid-rock reactions provides low risk and permanent CO2 removal. Here, we demonstrate rapid mineralisation of industrial CO2 emissions in mantle peridotites. Captured CO2 from an ammonia plant in the Sultanate of Oman has been injected into peridotite at a pilot test site in the Samail ophiolite. Chemical and isotopic results indicate rapid carbonate mineral precipitation. Mass balance calculations suggest that ~88% of the injected CO2 was mineralised as carbonate minerals within 45 days after injection. This successful approach of CCM unlocks peridotite as a promising new type of reservoir for the safe and permanent disposal of anthropogenic CO2 emissions.

Cumulative carbon dioxide emissions into the atmosphere have been estimated at 2035 ± 205 GtCO2 from 1870 to 20191. To limit the impact of global warming and subsequent climate change, the Paris agreement recommended to limit average warming of the atmosphere to <2 °C, preferably to 1.5° compared to pre-industrial levels1. To reach this goal, the level of global carbon dioxide removal coupled with permanent storage must be approximately 10 Gt CO2/yr by 2050 and 20 Gt CO2/yr by 21002. There are multiple storage options, with underground CO2 storage in sedimentary formations being the most mature technique, with over 200 Mt of anthropogenic CO2 being injected and stored in underground reservoirs for enhanced oil recovery by today3. Current estimates of aggregated global storage resources in underground reser- voirs (mainly deep saline aquifers and depleted oil & gas reservoirs) are 13,954 GtCO24. In this type of reservoirs, CO2 is primarily stored as supercritical or liquid CO2, with the tendency to migrate back to the surface due to buoyancy effects if not stored adequately. Another storage option is enhanced CO2 mineralisation in unconventional storage reservoirs, such as basalt and peridotite that mimics the natural process of silicate rock weathering5–12. In this approach, injected CO2 reacts with mafic and ultramafic rocks, which contain high concentrations of cal- cium, magnesium, and iron, required for CO2 mineralisation. Com- bining CO2 dissolution into water before or during the injection with in- situ CO2 mineralisation significantly increases storage permanence and security by immediate solubility trapping and subsequent mineralisation13–15.

Full paper available here:

https://www.nature.com/articles/s43247-025-02509-5