Gasification Characteristics and Kinetics of Coke with Chlorine Addition

Abstract

The gasification process of metallurgical coke with 0, 1.122, 3.190, and 7.132 wt pct chlorine was investigated through thermogravimetric method from ambient temperature to 1593 K (1320 °C) in purified CO₂ atmosphere. The variations in the temperature parameters that T_i decreases gradually with increasing chlorine, T_f and T_max first decrease and then increase, but both in a downward trend indicated that the coke gasification process was catalyzed by the chlorine addition. Then the kinetic model of the chlorine-containing coke gasification was obtained through the advanced determination of the average apparent activation energy, the optimal reaction model, and the pre-exponential factor. The average apparent activation energies were 182.962, 118.525, 139.632, and 111.953 kJ/mol, respectively, which were in the same decreasing trend with the temperature parameters analyzed by the thermogravimetric method. It was also demonstrated that the coke gasification process was catalyzed by chlorine. The optimal kinetic model to describe the gasification process of chlorine-containing coke was the Šesták Berggren model using Málek’s method, and the pre-exponential factors were 6.688 × 10⁵, 2.786 × 10³, 1.782 × 10⁴, and 1.324 × 10³ min⁻¹, respectively. The predictions of chlorine-containing coke gasification from the Šesták Berggren model were well fitted with the experimental data.