Here, the isothermal gasification of corn stalk char with carbon dioxide was studied experimentally using thermogravimetric analysis. The effects of varying the gasification temperature and CO2 partial pressure on the char gasification were analyzed. The reactivity index and the active site coverage were used to predict the char gasification characteristics. The results showed that the gasification reaction rate are positively correlated with both the temperature and CO2 partial pressure \(P_{\text{CO}_{2}}\) . The reactivity index can well describe the gasification characteristics of char under different experimental conditions, while the coverage of active sites can predict the gasification characteristics of char under different CO2 partial pressures, but it cannot explain the gasification characteristics of char at X = 0.4 under different gasification temperatures. Theoretically, the RPM, MRPM, and eRPM models were used to calculate the kinetic parameters of char gasification. The results showed that the eRPM model had the best fitting effect, and the activation energies calculated using eRPM models gradually decreased with increasing \(P_{\text{CO}_{2}}\) , and the intrinsic activation energies are larger than the corresponding apparent activation energies. In addition, we compared and summarized the model method, Flynn model, power law method, and L–H rate equation, and concluded that the power law method is the simplest and most accurate model.
