Entrained flow coal gasification process simulation with the emphasis on empirical devolatilization models optimization procedure

Computational fluid dynamic (CFD) modelling of entrained flow reactors is demonstrated and compared with experimental data. The current study is focused on the devolatilization modelling and its impact on gasification simulation results. An innovative procedure of optimizing input data to empirical devolatilization models is investigated, based on the complex phenomenological approach: the functional-group, depolymerization, vaporization, cross-linking (FG-DVC) model. The determined heating rates are used in detailed devolatilization calculations to find the optimized kinetic input to global empirical models. The study considers different approximation methods, i.e. the linear method, the exponential method and the minimization of the objective function, for the optimization procedure, focusing on their efficiency in volatile yield prediction. Performance of the optimization procedure is evaluated based on experimental data from two reactors: at Brigham Young University and University of Haute-Alsace. The first case considers entrained flow coal gasification. The investigation showed that uncertainties are present in the vicinity of the feedstock inlet during devolatilization. For this reason, further analysis was dedicated specifically to coal pyrolysis in an inert atmosphere. A significant influence of particle thermal history representation on the optimization procedure accuracy was reported. The optimization of global devolatilization models managed to improve the agreement with experimental data.