Effects of CO2 and H2O on coal pyrolysis with the ultrafast heating rate in a concentrating photothermal reactor. (October 2021)

• Record Type: Journal Article
• Authors: Huanying, Chi; Hanjian, Li; Sheng, Su; Shagali, Abdulmajid Abdullahi; Xiaoxue, An; Jun, Xu; Long, Jiang; Yi, Wang; Song, Hu; Jun, Xiang
• Is Part Of: Journal of the Energy Institute. Volume 98(2021)
• Page Start: 44
• Page End: 52
• Publication Date: 2021-10
• Subjects: CO2/H2O atmosphere -- Ultrafast heating rate -- Coal pyrolysis -- Correction factors -- Kinetics model; Power (Mechanics) -- Periodicals; Power resources -- Periodicals; Fuel -- Periodicals; 621.04205
• DOI: 10.1016/j.joei.2021.06.001
• Languages: English
• ISSNs: 1743-9671

Abstract

Abstract: A novel concentrating photothermal reactor with the ultrafast heating rate at around 1800 °C/min was developed to study the effects of CO2 and H2 O on coal pyrolysis for oxy-fuel combustion. The mass loss rate with the ultrafast heating rate increased by several decuples than that with the slow heating rate. Coal pyrolysis process with the ultrafast heating rate was promoted by CO2 within 50% concentration but inhibited for a further higher concentration (70%). The addition of H2 O into 30% CO2 exhibited a continuous positive role in coal pyrolysis with the ultrafast heating rate. Different from the satisfied prediction of chemical reaction models with the slow heating rates, diffusion models were of higher correlation coefficients for the ultrafast-heating pyrolysis process. The correction factors for CO2 and H2 O were determined accordingly, and the modified three-dimensional diffusion mechanism model based on Jander equation (D3 model) well described the ultrafast-heating coal pyrolysis process. Highlights: Coal pyrolysis with the ultrafast heating rate of around 1800 °C/min in CPR was studied. Coal pyrolysis was promoted within 50% CO2, but inhibited in 70% CO2 . The addition of H2 O into 30% CO2 exhibited a positive role in coal pyrolysis process. The correction factors for CO2 and H2 O were determined. The modified D3 model well described the ultrafast-heating coal pyrolysis process.