Effect of Ash on Coal Combustion Performance and Kinetics Analysis

ABSTRACT

In order to explain the influence of the coal ash on the combustion characteristics of coal, the physical and chemical structures of pulverized coal with different ash contents were compared and analyzed, and the combustion characteristics and kinetics of pulverized coal were systematically studied by non-isothermal thermogravimetric analysis. The results show that the physical and chemical structure of the deashed coal is not significantly changed compared with the raw coal. The combustion process of the deashed coal gradually moves to the high temperature zone, and the combustion performance is obviously weakened. The comprehensive combustion characteristic parameters of the three samples can be arranged as: raw coal > primary deashed coal > secondary deashed coal. In this study, the RNGM model was used to analyze the combustion kinetics of pulverized coal, and the fitting effect is good. And there is a significant kinetic compensation effect in the combustion process. After calculation, the activation energy value of the samples is between 16.15~29.51 kJ/mol. The RNGM model can effectively characterize the various stages of the combustion reaction and validate the experimental results.

KEYWORDS:

• Thermogravimetric analysis
• deashed coal
• comprehensive combustion characteristics
• kinetic model
• compensation effect

Supplementary material

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Additional information

Funding

This work was supported by the National Natural Science Foundation of China [No. 51804026]; The Yong Elite Scientists Sponsorship Program By CAST [2017QNRC001]; The Fundamental Research Funds for the Central Universities [2018FRF-NP-18-007].