Mineral Carbonation for CDR: How Close Are We to Commercial Viability?

Conceptual illustration of mineral carbonation (this image was AI generated)

Which technological developments strengthen the case for CDR?

The scientific basis is well established. Sanna et al. (2014) identified energy demand, reaction rates and material handling as major constraints on mineral carbonation, with product value central to the economics. Liu et al. (2021) highlighted similar limitations for industrial residues, including the need for equipment scale-up and lifecycle assessment. [1,2]

Accelerating carbonation involves managing coupled processes: mineral dissolution, CO₂ transfer and carbonate precipitation. In some silicate systems, reaction products form layers that hinder further dissolution/reaction. Julcour et al. (2015) demonstrated an attrition-leaching approach using a stirred bead mill to mechanically remove these layers during reaction. The work illustrates how reactor design can address a specific kinetic limitation. [3]

The relevant engineering question is broader than reaction speed.

But how much of this progress translates into a viable solution for carbon dioxide removal?

The answer depends on the entire pathway. A carbonation reaction establishes that CO₂ can be captured and stored. The origin of the CO₂ determines energetic and technical requirements as well as eligibility.

The CO₂ source determines a fundamental part of the climate claim:

Mineral carbonation (MC) converts CO₂ into solid carbonate minerals that can store carbon for very long periods. It works by reacting CO₂ with calcium- or magnesium-rich materials, typically alkaline rocks or industrial by-products. Mineralisation can occur in an engineered reactor, in materials exposed to atmospheric CO₂, or underground, although underground pathways are beyond the scope of this article. The feedstock and operating conditions determine how the reaction proceeds. [1,2]

CDR requires that CO₂ is not only locked into a solid carbonate but is also durably stored (not utilized or exposed to weathering) and that it is all done with a net removal benefit; Commercial viability then requires a system that can deliver that benefit reliably at a cost customers will pay.

What has been demonstrated?

Mineralisation-based CDR has moved beyond the laboratory, but the credited volume is still small and concentrated. Across the three registry methodologies discussed below, removal credits have so far been issued only under Puro.earth’s Carbonated Materials methodology: about 77,000 tonnes, of which 57% have been retired. A single supplier accounts for more than 99% of both issuances and retirements, while Isometric and Rainbow have projects and suppliers in the pipeline, but no credits have been issues as of today (07.10.2026). [7–9]

Beyond credited projects, the wider field is advancing through industrial demonstration plants, carbon-storing cementitious materials tested in demanding construction applications, and pilots connecting industrial capture to underground mineral storage.

This progress needs to be read at the right level. A successful reaction, an operating plant, a construction trial, a purchase agreement and an issued removal credit each answer a different question. Many of the most visible developments mineralise CO₂ from fuel combustion, kilns or limestone calcination: valuable emissions reductions, but not removals. Reported capacities and product footprints are not removal volumes.

Can the business model support net removal?

Mineral carbonation can serve several paying customers: emitters seeking storage, manufacturers buying materials, waste operators seeking treatment and buyers purchasing verified removals. Their revenues and climate claims are not interchangeable. Useful products can spread costs across more than one revenue stream, but product value depends on consistent quality, qualification, logistics and actual demand; a carbonate-bearing material is not automatically a suitable cement substitute.

Materials revenue can support a future CDR pathway, but an emissions-reduction business cannot become a removal business simply by changing its label. Eligible atmospheric-carbon sourcing may require different supply contracts, capture equipment, logistics and verification. The metric that matters is the cost per verified tonne of net CO₂ removed, and the economics must still work once those requirements are included.

So, what can make mineral carbonation a scalable CDR pathway?

Scale becomes possible when the chemistry, infrastructure, carbon accounting and customer demand work together.

• Suitable feedstocks and efficient processing. Mineralogy, reactive phases, variability and contaminants determine what can be processed safely and effectively. Industrial residues offer reactive material and existing handling infrastructure, but supply is regional and some residues already have established uses; natural silicates add mining, preparation and transport. Process design should optimise net removal and cost across the whole chain.

• A credible atmospheric-carbon supply. Direct atmospheric uptake avoids a separate concentrated-CO₂ supply chain, while DAC and eligible biogenic sources can support reactor or underground-storage pathways. Each option has its own energy, infrastructure and accounting requirements.

• Practical local integration. Bringing compatible feedstocks, CO₂, low-emission energy and storage or product outlets close together can improve project economics and reduce transport emissions. The opportunity must be demonstrated for the actual site.

• Products with demonstrated performance and secure storage. Construction use can support deployment when materials meet relevant specifications and buyers have a reason to adopt them. Durability assessment must also consider the carbonated material’s expected exposure and end-of-life conditions.

• MRV that measures the additional net benefit. Existing carbonate carbon and uptake that would have occurred without intervention must be distinguished from project-induced storage. Registry methodologies for ex-situ mineralisation, including Isometric’s Open System Ex-situ Mineralization protocol, Puro.earth’s Carbonated Materials methodology (currently under revision) and Rainbow’s Mineralization of Alkaline Materials (Ex Situ), differ in scope and structure but share this logic: eligible CO₂ origin, net accounting against a baseline and durable storage. Credible verification connects the geochemistry to a saleable removal claim. [4–6]

• Demand that supports repeated delivery. Materials customers and removal buyers can help finance deployment, but scale ultimately requires reliable operation, qualified outputs and verified removals over successive reporting periods.

Mineral carbonation already has functioning CDR applications. The wider opportunity is to extend those successes through pathways that combine additional atmospheric-carbon storage, manageable lifecycle emissions and viable project economics. Recent developments strengthen the case for continued deployment, while showing why every project needs to be evaluated on its complete carbon pathway.

Developing a mineral carbonation project or assessing its CDR potential?

CDRexperts can help evaluate the geochemistry, lifecycle boundaries and MRV requirements needed to move from CO₂ uptake to a defensible net removal claim. Get in touch at www.cdrexperts.org.

Sources

1. Sanna, A. et al. (2014). A review of mineral carbonation technologies to sequester CO₂. Chemical Society Reviews, 43, 8049–8080. https://doi.org/10.1039/C4CS00035H

2. Liu, W. et al. (2021). CO₂ mineral carbonation using industrial solid wastes: A review of recent developments. Chemical Engineering Journal, 416, 129093. https://doi.org/10.1016/j.cej.2021.129093

3. Julcour, C. et al. (2015). Development of an attrition-leaching hybrid process for direct aqueous mineral carbonation. Chemical Engineering Journal, 262, 716–726. https://doi.org/10.1016/j.cej.2014.10.031

4. Isometric. Open System Ex-situ Mineralization, v1.1. https://registry.isometric.com/protocol/open-system-ex-situ-mineralization/1.1

5. Puro.earth. Carbonated Materials methodology, Edition 2022 v3 (revision in progress). https://puro.earth/methodologies/carbonated-materials/

6. Rainbow Standard (19 March 2026). Mineralization of alkaline materials (ex situ), RBW-CDR-MIN-V1.1. https://docs.rainbowstandard.io/methodologies/mineralization-of-alkaline-materials-ex-situ

7. Puro Registry. Projects certified under the Carbonated Materials methodology. https://registry.puro.earth/projects

8. Isometric Registry. Projects, active and coming soon. https://registry.isometric.com/projects

9. Rainbow Registry. Projects under the Mineralization of Alkaline Materials methodology (RBW-CDR-MIN). https://registry.rainbowstandard.io/ledger/projects

Note: methodology versions and registry data as of 7 October 2026.