Filtration combustion of a carbon-inert material system in the regime with superadiabatic heating

Superadiabatic regimes of combustion of carbon mixed with an inert solid with filtration of the steam-air mixture are studied theoretically and experimentally. The temperature in the combustion wave and the composition of gaseous products are obtained as functions of the fraction of carbon in the fuel and the amount of steam in the gaseous oxidant. In the examined range of the control parameters, the maximum temperature in the combustion wave is shown to depend only slightly on the fraction of carbon in the mixture and the amount of steam in the oxidant gas. Simulations of filtration combustion of carbon with allowance for the kinetics of its oxidation are in good agreement with experimental results. The calculated combustion temperature coincides with that measured in experiments. In calculating the composition of the gaseous products, coincidence with experimental data is observed only for particular compositions with the mass content of carbon under 60%. As the fraction of the fuel exceeds 60%, the yield of CO and H₂ increases in experiments, though such a behavior is not predicted by the theoretical analysis. Hypotheses on the reasons for the disagreement in results are put forward and experimentally checked. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 3, pp. 30–38, May–June, 2008.