A Novel Method of Kinetic Analysis and Its Application to Pulverized Coal Combustion under Different Oxygen Concentrations

Abstract

Currently, many efforts have been made to improve the approach to build kinetic models. Based on mathematical algorithms, a novel method (named DIM method) of kinetic analysis was introduced in detail. A formula combining differential and integral was deduced and applied to the determination of the mechanism function f (α). Subsequently, multivariable linear regression was conducted to simultaneously obtain the apparent activation energy E, pre-exponential factor A, and oxygen concentration exponent n. In the application of pulverized coal combustion under different oxygen concentrations (3%, 5%, 10%, 15%, and 21%), E, A, and n were calculated as 258,164 J/mol, 6.660 × 10 17 s −1 , and 3.326, respectively, and the mechanism function f (α) was determined as the Avrami-Erofeev equation. A validation was performed under a 7% oxygen concentration, which shows that the DIM method has a higher accuracy. This work can provide a reference for the study of kinetic analysis.

An Introduction to the Combustion of Carbon Materials

“…The aim of kinetic studies is then to determine the triplet of the factors E a , f( α ) and n. Several formulations for the f( α ) function can be found elsewhere and can either arise from empirical laws (e. g. power laws, giving rise to a fixed reaction order for the carbon) or derived from models of structural evolution of the material during its conversion (e. g. contracting or shrinking core models). [ 69 , 240 , 241 ] Often, several functions are compared and the one giving the best fit is kept. E a (n) can then be obtained by studying the effect of temperature and/or oxygen partial pressure variations.…”

Thermal Oxidation of Carbonaceous Nanomaterials Revisited: Evidence of Mechanism Changes

“…Thermogravimetric analysis (TGA) is the most commonly applied technique to measure kinetic data, using either isothermal or constant heating rate experiments. Both of those have their own limitations and to improve accuracy Gou et al . recently proposed combining the two methods.…”

“…Thermogravimetric analysis (TGA) is the most commonly applied technique to measure kinetic data, using either isothermal or constant heating rate experiments.B oth of those have their own limitations [14][15][16][17][18][19][20] and to improve accuracy Gou et al [21] recently proposed combining the two methods. Many experimental parameters influence the precision and the results of TGA experiments and they have consequently been studied in detail in several studies in the last decades.…”

Thermal Oxidation of Carbonaceous Nanomaterials Revisited: Evidence of Mechanism Changes

“…Thermogravimetric analysis (TGA) is the most commonly applied technique to measure kinetic data, using either isothermal or constant heating rate experiments. Both of those have their own limitations [14][15][16][17][18][19][20] and to improve accuracy Gou et al [21] recently proposed combining the two methods. Many experimental parameters influence the precision and the results of TGA experiments and they have consequently been studied in detail in several studies in the last decades.…”