Model-based optimization of the operation of the coke calcining kiln

A mathematical model was recently developed to simulate the calcination process of regular petroleum coke suitable for aluminum industry applications. The model is made of 14 ordinary differential equations describing energy and mass conservation in the gas and in the coke bed, and complemented by correlations and algebraic equations. It calculates temperature and concentration profiles in the kiln, and also yields other information important to kiln operation, such as calcined coke recovery factor and coke loss through the generation of dust. In this paper it is demonstrated that the model is an efficient tool for the optimization of kiln operation. The model is used to study the effect of key control variables upon kiln operation and productivity. Further, it is shown that higher kiln productivity may be obtained with optimized kiln control and without loss of satisfactory kiln operating condition