Applying reactor model parameters to estimate pygas selective hydrogenation catalyst activity during operation cycle

• A trickle-bed reactor model is setup in commercial software.
• The temperature-dependent hydrodynamic parameters are calculated according to the highly exothermic reactor conditions.
• The hydrogenation rate constants during operation cycle are tuned semi-empirically with plant data.
• The rate constants variations are used to evaluate the residue catalyst activity.

The trickle-bed reactor model proposed by Mostoufi et al. was rebuilt for use in commercial software, Aspen Plus®. Coupling with thirty hydrogenation rate equations, the process model could simulate a pyrolysis gasoline hydrogenation unit. With an optimization procedure, the thirty rate constants were obtained after minimizing the relative-concentration-based objective function. In this work, the hydrodynamic parameters including physical properties were simultaneously calculated from the software platform according to the reactor conditions, such as temperature, concentration, etc. Therefore, the effect of parameter variation can be avoided not only along the catalyst bed, but also at the start of run and end of run. This semi-empirical method can be applied to highly exothermic hydrogenation reactor models, and then used it to estimate residue catalyst activity much more theoretically than the weighted average bed temperature method and interpret plant data more in practice, for example, bed temperature profile and its deviation, the relationship between the throughput and pressure drop.

By tuning the rate constants, a semi-empirical method can be applied to pygas selective hydrogenation reactor models, and then used it to estimate residue catalyst activity much more theoretically than the weighted average bed temperature method. Figure optionsDownload as PowerPoint slide