Comparison of temperature-programmed char combustion in CO2-O2 and Ar-O2 mixtures at elevated pressure

The effect of CO2 partial pressure of 0.57 MPa at P = 0.6 MPa total pressure on the overall reaction of a temperature-programmed combustion was studied. The kinetics of the char+O2 reaction was not influenced by a high amount of CO2. This is explained by several factors: 1) the char+CO2 reaction has a much lower rate than the oxidation; 2) the CO2 does not participate in the elementary reactions of the oxidation; 3) changes in ambient CO2 concentrations do not materially affect the concentration of evolved CO2 at the molecular level.