Evaluation of factors affecting mineral carbonation of CO2 using coal fly ash in aqueous solutions under ambient conditions

Abstract

This study examined the factors affecting mineral carbonation to sequester CO2 using coal fly ash (CFA) in aqueous solutions under ambient temperature and pressure conditions. Serial extraction and carbonation tests were conducted on CFA obtained from a coal-fired power plant as the following conditions were varied: solid dosage, CaO content, CO2 flow rate, and solvent type. The solid dosage, CaO content, and solvent type affected the Ca extraction efficiency, which was well correlated with the carbonation efficiency. In addition, at a given Ca extraction efficiency, the CO2 flow rate and the solvent type affected the rate and extent of CFA carbonation. Based on the study results, the CO2 sequestration capacity of CFA under ambient temperature and pressure conditions was approximately 0.008kg of CO2 per 1kg of CFA at the experimental test conditions (CaO content: 7wt.%, solid dosage: 100g/L, CO2 flow rate: 2mL/min, and solvent: DI water).