Combustion kinetics of coal dust

Numerical Prediction of Pulverized Coal Flame in Utility Boiler Furnaces

“…Determination of kinetic parameters for six Serbian lignites was done on the basis of the coal combustion experiments in vertical cylindrical 15 kW laboratory furnace (with combustion chamber internal diameter 71 mm) . All tests were carried out under steady operating conditions.…”

“…The concentration of oxygen in combustion products was also measured. It was assumed that the reaction rate constant k (m/s), determined on the basis of the measurements and corresponding expressions, followed a well-known Arrhenius expression: k = A e − E / RT (m/s), ln k = ln A − ( E / R T ) where A is pre-exponential factor (m/s), E is the coal activation energy (kJ/kmol), R is the universal gas constant [=8.314 kJ/(kmol·K)], and T is the gas temperature (K). Values of the reaction rate constant calculated for several vertical levels of the combustion chamber were presented in semilogarithm diagram, with ln K at ordinate plotted against 1/ T at abscise.…”

“…Intersection point between the interpolating curve (in this case straight line) and ordinate gave the value of pre-exponential factor A , while the coal activation energy E was obtained from the interpolating line inclination angle. The kinetic parameters obtained for the case-study coal (lignite Kostolac-Drmno) and used in the mathematical model were: A = 5.5 × 10 3 m/s and E = 9.95 × 10 4 kJ/kmol. , Experimental error, related to a dispersion of the coal reaction rate values around the interpolating line, could be estimated to be less than 5%.…”