Dynamic Modeling and Optimization of Steam Methane Reforming

The main goal of this research is dynamic modeling and optimization of the steam methane reforming process in an industrial hydrogen plant in a crude oil refinery. In the first step, the process is heterogeneously modeled based on the mass and energy balance equations considering catalyst deactivation. Since the reforming reactions are under mass transfer control in the catalyst, the effectiveness factor is calculated and applied in the model. Then, to verify the accuracy of the model, the simulation results are compared with the plant data. The simulation results show that hydrogen production capacity decreases and approaches from 27.4 to 24.4 mole/s due to catalyst deactivation. In the next step, considering the uniform hydrogen production as an objective function and operational limitations in the process, a single objective optimization problem is formulated to overcome the production decay. Based on the formulated optimization problem, the optimal dynamic trajectories of feed temperature, furnace temperature, and steam to methane ratio are calculated during the process run time. Based on the simulation results, the hydrogen production is improved by about 6% applying optimal conditions to the system.