Direct carbonation of peat-wood fly ash for carbon capture and utilization in construction application

• Published in: Journal of CO2 utilization 2020-09, Vol.40, p.101203, Article 101203
• Main Authors: Ohenoja, Katja, Rissanen, Jouni, Kinnunen, Paivo, Illikainen, Mirja
• Format: Article
• Language: English
• Subjects: Bio ash; Biomass fly ash; Carbon capture and utilization; Fluidized bed combustion; Wood ash; Woody ash
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2020.101203

•Carbon capture and utilization (CCU) via CO2 mineralization.•Biomass fly ash is suitable for direct carbonation in construction application.•CO2 mineralization during the hydration reactions of fly ash.•Improved compressive strength of hydrated fly ash. Carbon dioxide (CO2) emissions from industrial processes contribute largely to the greenhouse effect and climate change. One of these industries is the cement industry, which contributes around 8% of CO2 emissions caused by mankind. Two promising and interesting ways to reduce CO2 emission are the utilization of alternative cementitious materials and carbon capture and utilization through CO2 mineralization. In this study, peat-wood fly ashes from fluidized bed combustion were used as a construction material for mineral carbonation. A self-hardening characteristic of this type of fly ash was utilized, and simultaneous carbonation and hydration reactions were studied. The study showed that fly ashes from the fluidized bed combustion of peat and wood could be used to capture and mineralize CO2 during hydration reactions. At the same time, CO2 could improve the strength of self-hardened fly ashes. One interesting future possibility is fly ash tile production at energy plants: fly ashes can be used to capture CO2 from flue gases, thus improving the strength of produced tiles.