Assessment of CO2 absorption characteristics and carbon sequestration potential of fly ash mineralization reaction from different coal types
QIN Lei
LIN Siheng
LIN Haifei
LI Shugang
LIU Pengfei
MU Miao
Abstract：The particle size distribution and chemical composition of fly ash from different coal types are known to dir-ectly influence the carbon sequestration performance in mineralization reactions.Investigating the CO2 absorption charac-teristics of mineralization reactions is considered crucial for assessing the carbon sequestration potential of fly ash.Fly ash samples from several coal-fired power plants in Shijiazhuang,China,are analyzed using pressure drop and thermogravi-metric analysis methods to comprehensively characterize the CO2 absorption characteristics and carbon sequestration per-formance of mineralization reactions.The experimental results indicate that increasing the pressure and temperature of mineralization reactions enhances the carbon sequestration performance of fly ash.When the initial pressure is increased from 1.0 MPa to 2.0 MPa,the average CO2 absorption of fly ash from different coal types increases by 7.18 g/kg.When the temperature is raised from 40℃to 60℃,the average CO2 absorption increases by 4.28 g/kg.The pressure drop meth-od is found to result in non-mineralized CO2 absorption,leading to an overestimation of carbon sequestration performance compared to the thermogravimetric analysis method.Smaller particle sizes are observed to provide higher specific surface areas,promoting the interaction between CO2 and active components,which enhances carbon sequestration performance.A positive correlation is identified between the CO2 absorption of fly ash and Ca content,while a negative correlation is observed with S content.High-Ca fly ash exhibits superior carbon sequestration performance due to its abundance of react-ive materials.Sulfur in fly ash,primarily in the form of sulfates,competes with calcium during reactions,inhibiting car-bonate formation and reducing carbon sequestration performance.Among the fly ash samples analyzed,fly ash from An-huaneng Thermal Power Plant(AH)exhibits stable CO2 absorption and mineralization carbon sequestration efficiency.Fly ash from Huadian Thermal Power Plant(HD)demonstrates relatively high CO2 absorption capacity.Fly ash from Xibaipo Thermal Power Plant(XB)shows the highest and most stable CO2 absorption and mineralization carbon sequestration effi-ciency,indicating the greatest potential for carbon sequestration in mineralization reactions.
Keywords：CO2 sequestrationCarbon Capture Utilization and Storage(CCUS)multi-rank fly ashdirect mineraliza-tionmineralization condition optimizationcarbon sequestration performance characterization
Publication Date：2025-09-27
Online Publishing Date：2025-10-22(First online date of this platform, not the publication date of the document)
Pages：12( 4464-4475 )