Hydrogen Evolution during Devolatilization To Predict Coking Potential of Metallurgical Coals

Abstract

Evolution of hydrogen during the plastic state is a key parameter in coke making for the production of quality coke. Based on this phenomenon, a new devolatilization method has been developed for accessing the coking property of coals using the evolution of H2 during thermogravimetric–mass spectrometer (TG-MS) analysis. Four coals having different coking potentials, commonly used in steel industries, were considered. The investigation was performed at temperatures up to 1100 °C in an argon atmosphere under a constant heating rate of 3 °C/min to simulate the coking environment. Nonisothermal kinetics is considered as a good indication of different reaction regimes during pyrolysis, which is generally done through TGA alone. In this study evolution of H2 is used to develop nonisothermal kinetics through a new quantification approach. Finally, a definite and more generic correlation was established, based on H2 enrichment in volatiles around specific temperature zones, for measuring the exact coking behavior...