Modeling and numerical simulations of lignite char gasification with CO2: The effect of gasification parameters on internal transport phenomena

The purpose of this study is to develop an experimental data-based char particle gasification model in order assess the effects size, temperature and generation heating rate on global parameters. Also, effect initial porosity observed by performing parametrical numerical simulations. A continuum-based used solve inside a within external boundary layer. intrinsic CO2 reaction computed according Langmuir-Hinshelwood (LH) mechanism. External mass transfer modeled Stefan-Maxwell relations, Cylindrical Pore Interpolation Model (CPIM) for intra-particle molecular diffusion. In model, all due internal structure changes are represented conversion function, f(X) which from local values. study, deduced results instead phenomenological models almost impossible validate. best reproduction obtained function postulated as summation two Gaussian functions represent random pore structures their dynamics during gasification. Comparative simulation show that low interval shifted even lower values higher porosity. Thereby, rates (large sizes) interpreted representative diffusion-limited regime conjunction with network macropores diffusion rates. modification causes shift second towards It therefore corresponds layer diffusion-controlled related available outer surface area particle.