Assessment on combustion performance and bottom ash properties of carbon‐rich fraction from coal gasification fine slag co‐combustion with corn straw char. (1st July 2022)

• Record Type: Journal Article
• Authors: Jia, Wenke; Guo, Yang; Xu, Jie; Qiu, Guofeng; Wang, Rumeng; Li, Yan; Xue, Manman; Zhang, Yixin; Wu, Jianjun
• Is Part Of: International journal of energy research. Volume 46:Number 12(2022)
• Page Start: 16500
• Page End: 16511
• Publication Date: 2022-07-01
• Subjects: carbon‐rich fraction -- corn straw char -- co‐combustion performance -- reaction kinetic -- bottom ash properties; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.8312
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: In this paper, the co‐combustion characteristics of the carbon‐rich fraction from coal gasification fine slag and corn straw char were investigated. The combustion performance of the blend was studied by TGA, and the properties of bottom ash samples were evaluated by XRD, SEM‐EDS, and ICP‐MS. The results showed that the addition of corn straw char (CC) to carbon‐rich fraction (RC) can improve the combustibility of RC. The kinetic reaction mechanisms of the blend combustion were described by the diffusion model and chemical reaction order model (D1 and O3). The 40%RC case was recommended because of the lowest reaction activation energy. Hematite (Fe2 O3 ), quartz (SiO2 ), anhydrite (CaSO4 ), and diopside (Ca(Mg, Al)(Si, Al)2 O6 ) were the main mineral compounds in the RC‐CC ash. With different compounding ratios of RC‐CC, significant variability was observed in the degree of denseness and aggregation on the surface of the blend combustion bottom ash. The heavy metal concentrations (V, Cr, Ni, As, Cd and Pb) in the ash were tested to be in accordance with Chinese soil environmental quality standards, and the co‐combustion process had a positive impact on the enrichment of V, Cr, and Ni in the bottom ash to some extent. The results obtained can make a reference for the synergistic utilization of RC‐CC, and the treatment and reuse of combustion bottom ash samples. Abstract : In our study, it is found that the ignition and burnout performance of the carbon‐rich fraction are enhanced with the addition of corn straw char. Due to the different mixing ratios, the mineral composition of the bottom ash shows different changes. It can be observed that the ash sample with 40% mixing carbon‐rich fraction proportion presents the most obvious agglomeration phenomenon. Besides, the bottom ash is rich in silicon, which can be extracted and reused. Moreover, the heavy metal contents in the bottom ash all meet the Chinese Standard of Soil Environmental Quality Risk Control Standard. The results obtained from this paper aim to guide the large‐scale treatment of coal gasification fine slag in the Ningdong region, China. Additionally, the study could make a practical reference for the potential of coal gasification fine slag as energy recovery.