Performance evaluation of carbon dioxide sequestration in oil shale fly ashes

This work investigated the performance of oil shale fly ashes (OSFA) as feedstock for CO₂ mineral carbonation using an ammonium salts based pH swing process. A CO₂ uptake of 156 kg CO₂/t ash was obtained for the OSFA from cyclones. This CO₂ uptake was similar to that previously obtained using a direct mineral carbonation process with less favorable process scale up conditions. Among pulverised fuel ashes, OSFA samples collected from the electrostatic precipitation tend to present lower CO₂ uptake compared to the OSFA sample obtained from the cyclones. OSFA from circulating fluidised beds were found to be less attractive for CO₂ sequestration process with ammonium salts.