Coal Particle Devolatilization and Soot Formation in Pulverized Coal Combustion Fields

Abstract

In this paper, recent developments of the devolatilization model and soot-formation model for the numerical simulations of pulverized-coal combustion fields, and the technology used to measure soot particles in pulverizedcoal combustion fields are reviewed. For the development of new models, the validation of the developed models using measurement is necessary to check the accuracy of the models because new models without validation have a possibility to make large errors in simulations. We have developed the tabulated devolatilization process model (TDP model) that can take into account the effect of particle heating rate on the volatile matter amount and the devolatilization-rate parameters. The accuracy of the developed TDP model was validated by using the laser Doppler velocimetry data for the bench-scale coal combustion test furnace. The soot-formation model combined with TDP model for the large eddy simulation (LES) has been also developed. The spatial distributions of both the soot-volume fraction and the polycyclic aromatic hydrocarbons were measured by virtue of laser-induced incandescence (LII) and laser-induced chemiluminescence (PAHs-LIF). The accuracy of the developed sootformation model was validated by using the measured data.

A review of the mineralogical and chemical composition of nanoparticles associated with coal fires

“…The composition of emissions (gasses, particles) depends principally on the following factors: (a) composition, morphology, and microstructure of the coal (or any other biomass) (Li, Wang, et al., 2020; Lighty et al., 2000); (b) intrinsic thermophysical properties, such as density of hot spots, temperature, and temperature gradients (Deng et al., 2021; Fletcher et al., 1997; Hashimoto & Hayashi, 2021; Lighty et al., 2000); (c) thermal forces created by air density and temperature differences, which control the flux of oxygen and moisture toward the composition zone (Dindarloo et al., 2015; Ribeiro et al., 2016); (d) distance between the combustion zone and vents (O'Keefe et al., 2011); and (e) the presence of volatile elements such as N, Hg, and S (which depends on the composition of the coal, host rock, and temperature) (O'Keefe et al., 2010; Zhang et al., 2013).…”