Modeling and Simulation of a Methanol-To-Olefines Fixed-Bed Reactor in Steady-State and Dynamic Conditions

In this paper modeling and simulation of a methanol-to-olefins (MTO) fixed-bed reactor has been investigated in both steady-state and dynamic conditions. In this study, the reactor was modeled as one-dimensional pseudo-homogeneous system. Then, in first step, the reactor was simulated at steady-state conditions and the effect of different parameters such as inlet flow rate, inlet temperature and cooling fluid temperature on the reactor performance was studied and optimal values of the parameters was obtained . In next step, dynamic simulation of the process was performed by using optimal values of the parameters and the effect of disturbances in these parameters on open-loop behavior of the reactor was investigated. Simulation results show that an increase in the temperature of inlet stream has negative effect on product quality, which is mostly because that the main reaction is exothermic. Further, adding water to the inlet stream decreases maximum temperature within the reactor and also prevents catalyst deactivation driven by coke formation. Because the main reaction is exothermic, cooling fluid is needed for heat rejection and the temperature of the cooling fluid has a great effect on products yields and temperature of the outlet stream from the reactor