A Microscopic and Kinetic Study of Coal Particle Devolatilization in a Laser Beam

摘要: Data are presented for the devolatilization weight loss of particles Pittsburgh seam bituminous coal (36 pet volatility by ASTM method) exposed to a laser beam in nitrogen environment. The rate was measured as function input flux, which varied between 75 and 400 W/cm2., particle diameter, 51 310 pm. “half-life” process directly proportional diameter inversely absorbed flux. This new experimental method, direct measurements single or small arrays particles, permitted data be correlated with scanning electron microscopic observations morphological changes resulting from each exposure heating For flux an air environment, essentially same is observed initially; however, when complete, it followed heterogeneous char oxidation occurs on much slower time scale. From totality records, size, dependence, appears that reaction mechanism involves simple, inward progression laminar pyrolysis-devolatilization wave surface. Simple thermodynamic transport constraints require pyrolysis velocity determined sum absorbing heat necessary raise element solid its temperature (500° 600° C), plus required supply devolatilization. then simply controlled traverse through it, predicted observed.