Environmental assessment of CO2 mineralisation for sustainable construction materials. (February 2020)

• Record Type: Journal Article
• Authors: Di Maria, Andrea; Snellings, Ruben; Alaerts, Luc; Quaghebeur, Mieke; Van Acker, Karel
• Is Part Of: International journal of greenhouse gas control. Volume 93(2020)
• Publication Date: 2020-02
• Subjects: Mineral carbonation -- Stainless steel slag -- Life cycle assessment -- CO2 capture and utilisation; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2019.102882
• Languages: English
• ISSNs: 1750-5836

Abstract

Highlights: Carbonation presents potential environmental benefits. The CO2 uptake is higher than the CO2 emitted by the carbonation process. Electricity and CO2 recovery are key parameters to improve environmental performance. Abstract: Mineral carbonation is a carbon utilisation technology in which an alkaline material reacts with carbon dioxide forming stable carbonates that can have different further uses, for instance as construction material. The alkaline material can be a residue from industrial activities (e.g. metallurgic slags) while CO2 can be recovered from industrial flue gasses. Mineral carbonation presents several potential environmental advantages: (i) industrial residues valorisation, (ii) CO2 sequestration and (iii) substitution of conventional concrete based on Portland cement (PC). However, both the carbonation and the CO2 recovery processes require energy. To understand the trade-off between the environmental benefits and drawbacks of CO2 recovery and mineral carbonation, this study presents a life cycle assessment (LCA) of carbonated construction blocks from mineral carbonation of stainless steel slags. The carbonated blocks are compared to traditional PC-based concrete blocks with similar properties. The results of the LCA analysis show that the carbonated blocks present lower environmental impacts in most of the analysed impact categories. The key finding is that the carbonated blocks present a negative carbon footprint. Nonetheless, the energy required represents the main environmental hotspot. An increase in the energy efficiency of the mineral carbonation process and a CO2 valorisation network are among the suggestions to further lower the environmental impacts of carbonated blocks production. Finally, the LCA results can promote the development of policy recommendations to support the implementation of mineral carbonation technology. Further research should enable the use of mineral carbonation on a broader range and large volume of alkaline residues.