Post-processing pathways in carbon capture and storage by mineral carbonation (CCSM) towards the introduction of carbon neutral materials

Abstract

Carbon dioxide capture and storage by mineral carbonation (CCSM) is a technology that can potentially sequester billions of tonnes of carbon dioxide (CO₂) per year. Despite this large potential, the costs of CCSM are currently too high for a large deployment of the technology and new systems are being investigated to attempt to overcome these limitations. To improve this situation, the successful development of post-processing routes creating marketable carbon neutral products could help the deployment of mineral carbonation. This work investigates the current market for CCSM products and the role they can play in decreasing the overall cost of CCSM technology. The current global market for the raw commodities, primarily cement additives, fillers and iron ore feedstock which could be produced by rock and/or industrial waste/by-product mineralisation, is about 27.5 Gt and can be easily flooded assuming 10% of the global CO₂ emissions sequestered by CCSM. The CCSM technology chosen will play a very important role in the products created, available post-processing routes and accessible markets if the resultant materials are of high purity. Low-value applications such as fill for land reclamation may represent the only viable opportunity at the current state of the technology, bearing in mind that these materials are competing with low-cost materials (i.e. crushed rock) and that the size distribution of the carbonated materials may need significant alteration to make them potentially useful. However, there is a lack of information available on the quality of the CCSM products towards access to high-value markets such as micro-silica and PCC. In summary, CCSM post-processing might be viable only in niche high-value markets, while low-value applications such as land/mine reclamation are potentially more feasible and could be able to absorb Gts of CCSM products.