A Study on the Applicability of Kinetic Models for Shenfu Coal Char Gasification with CO2 at Elevated Temperatures

In this paper, measurements of the CO2 gasification kinetics for two types of Shenfu coal chars, which were respectively prepared by slow and rapid pyrolysis at temperatures of 950 °C and 1,400 °C, were performed by an isothermal thermo-gravimetric analysis under ambient pressure and elevated temperature conditions. Simultaneously, the applicability of the kinetic model for the CO2 gasification reaction of Shenfu coal chars was discussed. The results showed: (i) the shrinking un-reacted core model was not appropriate to describe the gasification reaction process of Shenfu coal chars with CO2 in the whole experimental temperature range; (ii) at the relatively low temperatures, the modified volumetric model was as good as the random pore model to simulate the CO2 gasification reaction of Shenfu coal chars, while at the elevated temperatures, the modified volumetric model was superior to the random pore model for this process; (iii) the integral expression of the modified volumetric model was more favorable than the differential expression of that for fitting the experimental data. Moreover, by simply introducing a function: A = A ★ exp(ft), it was found that the extensive model of the modified volumetric model could make much better predictions than the modified volumetric model. It was recommended as a convenient empirical model for comprehensive simulation of Shenfu coal char gasification with under conditions close to those of entrained flow gasification. OPEN ACCESS Energies 2009, 2 546