Non-LTE thermodynamic properties for combustion processes

Abstract

The nonequilibrium thermodynamic properties of a product-gas derived from fluidized combustion of Pittsburgh seam coal is obtained using a multitemperature statistical thermodynamic computer model. Concentrations of 18 species are determined as a function of translational temperature (500 < T < 2500 K), pressure (0.1, 1.0, and 10 atm), and vibrational-to-translational temperature ratios of 0.5, 1, 2, and 5. The rotational and electronic excitation temperatures are assumed equal to the translational temperature. The partition functions and usual thermodynamic properties are also calculated and a nonequilibrium Mollier diagram is presented. The multitemperature model assumes chemical equilibrium and therefore represents a first step in describing nonequilibrium combustion reactions in a semiclassical manner. The model can be applied to reactions via chemical kinetics and/or an extension to a multichemical nonequilibrium model. The results indicate the relative concentration of species usually considered to be pollutants, under the range of conditions examined.