Dynamic Modeling and Validation of an Industrial Vacuum Thermodeasphalting Column for the Regeneration of Used Oil

Dynamic process simulation is a valuable strategy to enhance the reliability of transient operations in chemical plants. Deviations from normal operating conditions may be necessary to perform corrective actions against any external disturbance that may alter the performance of some process units. Moreover, some standard plant operations are intrinsically transient in nature, such as start-up and shut-down procedures. Used oil waste re-refining industry is beginning to explore this strategy, which could lead to successful outcomes, similarly to what has been observed in the crude oil refining industry. This work proposes a modeling approach for the dynamic simulation of a thermodeasphalting column for the regeneration of used oil, currently operative in the Itelyum Regeneration re-refining facility in Pieve Fissiraga. The modeling strategy introduces a discretization of the column sections, a reasoned choice of appropriate thermodynamic methods, and the calculation of the main equilibrium and transport parameters necessary to solve mass, energy, and momentum balances on the column sections. The model is validated with experimental data, showing good agreement regarding both manipulated and controlled variables, thus becoming a valuable tool for the aprioristic evaluation of critical transient operations such as start-up, shut-down, and accidents simulation.