Mineral Carbonation for Carbon Dioxide Sequestration

Mineral carbonation harnesses the natural affinity of carbon dioxide for alkaline earth minerals—primarily calcium and magnesium silicates—to form stable carbonate minerals. By accelerating this thermodynamically favourable reaction, carbon dioxide can be permanently immobilised in benign solid phases. Two main approaches exist: in situ carbonation, which leverages geological formations to stimulate natural weathering processes, and ex situ carbonation, in which crushed minerals or industrial residues are reacted with concentrated CO₂ streams under controlled conditions. Both methods offer the dual benefit of long-term storage and the potential valorisation of waste materials, such as steel slag, cement kiln dust or mine tailings. Technical challenges centre on reaction kinetics, energy requirements for mineral preparation and product separation, and overall process integration within industrial clusters. Advances in reactor design, heat integration and electrolyte management are gradually closing the energy and cost gaps relative to conventional geological sequestration. Mineral carbonation is emerging as a globally significant route to net-negative emissions, particularly for sectors where high-purity CO₂ streams or abundant alkaline residues are available.

Research from Nature Portfolio

Recent studies have demonstrated the viability of an enhanced weathering cycle using magnesium oxide derived from magnesite calcination. By spreading reactive MgO over land, ambient CO₂ is sequestered via natural carbonation over periods of months to a year, after which the carbonate is recollected and re-calcined. This closed loop has been shown to achieve net removal costs in the range of US$46–159 per tonne of CO₂, comparing favourably to other direct air capture technologies. Pilot-scale trials suggest that deployment across arid or semi-arid terrains could yield multi-gigatonne annual removal capacity with modest land-use footprints.

Complementary advances have focused on tuning chemical interactions during mineral carbonation to broaden its applications beyond storage. By controlling solution chemistry, pH and mineral surface properties, researchers have engineered reaction pathways that favour the formation of high-value carbonate polymorphs and composite materials. Such developments not only enhance carbonation rates but also open avenues for integrating CO₂ conversion into chemical manufacturing and energy storage systems, thereby improving overall process economics.

Mineral Carbonation for Carbon Dioxide Sequestration publication trend

The graph below shows the total number of articles in mineral carbonation for carbon dioxide sequestration across all publications each year (not limited to Nature Index journals).

Technical terms

Mineral carbonation: A process in which CO₂ reacts with alkaline earth minerals or residues to form stable carbonate minerals, permanently trapping carbon.

In situ carbonation: The stimulation of natural weathering reactions within geological formations by injecting CO₂ or modifying subsurface conditions, leading to carbonate precipitation underground.

Ex situ carbonation: The controlled reaction of CO₂ with mined or waste-derived minerals in reactors or open systems, often enabling faster kinetics and product separation.

Enhanced weathering: The deliberate acceleration of natural silicate or oxide weathering processes, typically through mineral dissolution or surface activation, to increase atmospheric CO₂ uptake.

References

1. On the role of system integration of carbon capture and mineralization in achieving net-negative emissions in industrial sectors. Energy & Environmental Science (2023).
2. Calcium Carbonate Precipitation for CO2 Storage and Utilization: A Review of the Carbonate Crystallization and Polymorphism. Frontiers in Energy Research (2017).
3. A review of mineral carbonation technologies to sequester CO 2. Chemical Society Reviews (2014).
4. Ambient weathering of magnesium oxide for CO2 removal from air. Nature Communications (2020).
5. Scientific and Engineering Progress in CO2 Mineralization Using Industrial Waste and Natural Minerals. Engineering (2015).
6. Carbon mineralization pathways for carbon capture, storage and utilization. Communications Chemistry (2021).