Comprehensive gasification modeling of char particles with multi-modal pore structures

Numerical modeling of combined partial oxidation and gasification zones in a downdraft gasifier fueled by almond shell

“…The proportion of each gas species depends on the temperature of the char particles. Several correlations expressing the CO to CO 2 molar ratio as function of the char temperature were given in literature [9,[11][12][13][14]. The correlation (3) used by [14] is retained in this study.…”

The influence of gasification reactions on char consumption under oxy-combustion conditions: Effects of particle trajectory and conversion

“…A comprehensive, transient, single particle char consumption model has been developed and validated [18]. The model is a one-dimensional, spherically symmetric simulation of a reacting, porous char particle and its surrounding boundary layer, which solves PDEs for conservation of gas species, energy and mass and ODEs for pore growth variables [19] for each pore size [20].…”

“…Prior to devolatilization, the porosity of Lausitz lignite coal has been measured as 44% [28] and chars generated from Lausitz lignite, particularly in CO 2 -containing environments, have been shown to be highly porous, to possess very large surface areas and do not exhibit any swelling [29]. This indicates that, perhaps atypically for lignites, these char particles have significant amounts of both macro-and micro-porosity and the pore structure of the basecase char particles was assigned accordingly; the wide pore size distribution of Spherocarb char has been employed and is divided as in [18]. The true (helium) density of the char particles was assumed to be 1700 kg/m 3 to bring their mass and diameter in line with the particles used in the CFD simulation upon completion of devolatilization.…”

Kinetic modelling of char gasification by accounting for the evolution of the reactive surface area

“…The modelling of RSA evolution is combined with a random pore model (Bhatia and Perlmutter, 1980) for the modelling of the evolution of TSA upon the conversion of char particle. A similar approach could be used with more advanced structural models (Bhatia and Vartak, 1996;Haugen et al, 2014;Kantorovich and BarZiv, 1994;Morimoto et al, 2006;Singer and Ghoniem, 2013). The model is then applied to study the effect of intra-particle gas diffusions as functions of char particle size and temperature of gasification.…”