Optimizing industrial tunnel kiln operations for ceramic roof tile production: A bi-objective approach

Abstract

The ceramic firing process constitutes a highly energy-intensive production step that significantly affects the quality and final properties of the ceramic product. This work presents a model-based, bi-objective optimization approach for an industrial-scale tunnel kiln used in ceramic roof tile production, focusing on the exploration of trade-offs between productivity and thermal energy consumption. Initially, sintering kinetics are established based on lab experiments and integrated within a novel physics-based tunnel kiln model, thus allowing sintering evolution to be considered for the derivation of the optimal kiln operation. Two bi-objective optimization studies are then conducted to explore trade-offs under steady-state and transient-state kiln operations, thus generating a set of non-dominated operating policies. The attained Pareto optimal solutions are then evaluated with respect to the values of Specific Energy Consumption (SEC), which is distinctly minimized. This results in optimal SEC values of 0.283 for the steady state and 0.277 kWh/kg for the transient state kiln operation.