Comparison of the Peak Relief Rate Estimated by Dynamic Simulators Compared to Traditional Methods for Several Distillation Columns

Process engineers and designers have recently turned to using dynamic analysis as a more realistic method for sizing relief systems. The primary goal of using dynamic analysis is to ensure that modifications are required instead of making unnecessary and costly upgrades of relief systems based on conservative calculations. In work previously performed by the authors, it has been shown that, for certain overpressure scenarios, the peak relief load predicted by dynamic simulation is significantly lower than that predicted using traditional methods. 

This paper shows the differences in relief loads between traditional calculations and dynamic simulations for multiple different column systems and multiple different overpressure scenarios.  The column systems are based on installations the authors have encountered at various refineries and chemical plants throughout the world. The study also includes a sensitivity analysis that shows the effects of variables on peak relief loads and peak durations for different types of relief scenarios.