Numerical simulation of the hybrid filtration combustion of biomass

Hybrid filtration combustion waves in a porous media were numerically analyzed for biomass and methane-air mixtures. Temperature and products of the combustion waves were studied in the range of equivalence ratio from 0.2 to 1.1. A model, based on a two-temperature approximation and combustion chemistry is developed to analyze temperature profiles and species of the phenomena. The numerical solutions predictions for temperatures and chemical products are in good agreement with experimental data for some biomasses contrasted. It was found that with ultra-lean methane mixtures, the combustion temperature presents essentially higher values than stoichiometric mixtures. Experimental validation suggests that the chemistry of the process is very sensitive to CO formation. For low values of the biomass fraction in the porous medium, it is found that homogenous reactions are dominant whereas for high values (over 40%) the heterogeneous reactions are more influent. Thus, for ultra-lean methane-air mixtures, hydrogen production is enhanced when the biomass fraction in the medium is increased.