Coal pyrolysis in a rotary kiln: Part 2. Overall model of the furnace

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 31; no. 2
• Main Authors: Patisson, F., Lebas, E., Hanrot, F., Ablitzer, D., Houzelot, J.L.
• Format: Journal Article
• Language: English
• Published: United States 01.04.2000
• Subjects: 01 COAL, LIGNITE, AND PEAT; COAL; GAS FLOW; HEAT TRANSFER; KILNS; MATHEMATICAL MODELS; PARAMETRIC ANALYSIS; PYROLYSIS; SOLIDS FLOW; VALIDATION
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-000-0057-4

In order to simulate coal pyrolysis in a rotary kiln in the steady-state regime, a mathematical model has been developed which calculates the temperature profiles in the charge, the gas, and the furnace walls, together with the gas composition and the degree of removal of volatile species. The model takes into account the principal physiochemical and thermal phenomena involved, including the complex movements of the charge; the gas flow; heat transfer between the charge, the gas phase, and the furnace walls; drying and pyrolysis of the coal; the cracking of tars; the combustion of volatile species; and the combustion and extinction of the coke. The data necessary for the model were obtained by specific experiments or from the literature. The model has been validated by comparing its predictions to measurements performed to an industrial rotary kiln. The model has been used to study the influence of operating parameters such as the furnace rotation speed, in order to optimize the process. It is shown how a modification to the extinction zone leads to an increase in coke yield of 0.75 pct.