Thermal decomposition and ignition of coal

Effect of pore structure on particle ingition during exothermic gasification reactions

“…Particle ignition temperature has frequently been used to characterize char reactivity (Hoffman and Schnitzer, 1968;Patrick and Shaw, 1972;Pai Vernekar et al, 1982). A particle ignites when the energy generated by exothermic reactions exceeds the energy removed by convection or radiation to the extent that the particle temperature suddenly jumps to a high temperature steady state.…”

“…Consequently, the particle ignition characteristic is expected to be affected by its pore structure. Although the temperature rise and particle ignition phenomena in gas-solid reactions have been theoretically studied by various workers (Vulis, 1961;Luss and Amundson, 1969;Sohn, 1973;Stevenson et a]., 1973), there seems to have been no attempt to address specifically the effect of pore structure on the ignition behavior until the recent experimenal work of Pai Vernekar et al (1982). These latter authors suggested that the ignition temperature of a coal pellet is a function of the pellet porosity.…”