Thermal Risk Assessment of the Complex Nitration Process through Safety Operating Space Analysis and Optimization

Thermal runaway incidents often imply explosions and casualties, especially for the nitration process. However, limited by coupling relations among units, it is challenging to analyze thermal safety in a complex process. In this study, a novel solution strategy is proposed to analyze the safe steady-state operating space for a complex nitration process with seven reactors in a countercurrent connection. The thermal risk issue is assessed in detail by mechanism-based modeling and simulation. A multilevel optimization model is designed to quantify the safe operating space under a specified working condition. Based on the assessment model of thermal risk, an optimization solution strategy is proposed to find the optimal working condition that corresponds to the largest safe operating space. The case study shows that the safety operating space of the nitration process can be expanded by 67.38%. The proposed framework has the potential to enhance thermal safety for complex industrial processes.