Evaluation of reaction mechanisms and emissions of oily sludge and coal co-combustions in O2/CO2 and O2/N2 atmospheres. (June 2021)

• Record Type: Journal Article
• Authors: Zou, Huihuang; Liu, Chao; Evrendilek, Fatih; He, Yao; Liu, Jingyong
• Is Part Of: Renewable energy. Volume 171(2021)
• Page Start: 1327
• Page End: 1343
• Publication Date: 2021-06
• Subjects: Cleaner energy production -- Oxy-fuel -- Kinetic analysis -- Flue gases -- Process optimization; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2021.02.069
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Oxy-fuel combustion technology presents promising potential for the thermal disposal of hazardous waste to alleviate the global greenhouse effect on the environment and human well-being. In this study, the co-combustion reaction mechanisms and cleaner and efficient performances of oily sludge (OS) and coal in the oxy-fuel (O2 /CO2 ) and air (O2 /N2 ) atmospheres were characterized. With O2 concentration of 21% and at 20 °C/min, the ignition and burnout temperatures of the OS combustion were slightly worse in the oxy-fuel (403 and 531 °C) than air (407 and 535 °C) atmosphere. The rising O2 concentration increased the comprehensive combustion characteristic index from 1.11 × 10 −7 to 4.29 × 10 −7 in the air atmosphere and 1.02 × 10 −7 to 4.10 × 10 −7 in the oxy-fuel atmosphere. Based on the master-plots method, the three combustion stages of light oil, heavy oil, and fixed carbon were best described by the three-dimensional diffusion, interfacial reaction, and random nucleation growth models, respectively. The reaction mechanisms were independent of heating rate, O2 concentration, and atmosphere type. The co-combustion interaction between 70% OS and 30% coal reduced NO and SO2 emissions. Our findings can provide new insights into achieving their cleaner and more efficient co-combustion performance and its operational optimization. Graphical abstract: Image 1 Highlights: Oxy-fuel co-combustion properties of oily sludge and coal were quantified. Reaction mechanism was independent of heating rate, O2 concentration and atmosphere. The oxy-fuel atmosphere lowered the E values of the three OS combustion stages. Optimal co-combustion efficiency was achieved with 30% coal under 30% O2 /70% CO2 . Co-combustion reduced NO and SO2 emissions by 4.9 and 4.1%, respectively.