Model Predictive Control for Hydrogen Production in a Membrane Methane Steam Reforming Reactor

The main aim of this study is the design of an optimal model predictive controller (MPC) scheme for the control of a fixed-bed membrane reactor (MR) for H2 production via low temperature methane steam reforming (MSR). Reactions take place over a Ni-Pt/CeZnLa foam supported catalyst at an operating temperature of 773 K and pressure of 106 Pa. A permeable membrane with Pd-Ru deposited on a ceramic dense support is used to selectively remove the produced H2 from the reaction zone. In this way, the separated H2 is free of CO2 and CO, whereas chemical equilibrium is shifted favourably towards H2 production, thus enabling the achievement of a high CH4 conversion at relatively low temperature levels. A rigorous nonlinear dynamic model has been developed assuming one dimensional transport and pseudo-homogenous conditions in the reaction zone in order to emulate the plant dynamics, whereas a linearized version of it is employed for the MPC algorithm. Simulated case studies of the control scheme on the nonlinear system confirm the controller ability to achieve the desired dynamic behaviour both in the case of H2 production changes and disturbance compensation.