Control of natural gas catalytic partial oxidation for hydrogen generation in fuel cell applications

A fuel processor that reforms natural gas to hydrogen-rich mixture to feed the anode field of fuel cell stack is considered. The first reactor that generates the majority of the hydrogen in the fuel processor is based on catalytic partial oxidation of the methane in the natural gas. We present a model-based control analysis and design for a fuel processing system (FPS) that manages natural gas flow and humidified atmospheric air flow in order to regulate 1) the amount of hydrogen in the fuel cell anode and 2) the temperature of the catalytic partial oxidation reactor during transient power demands from the fuel cell. Linear feedback analysis and design is used to identify the limitation of a decentralized controller and the benefit of a multivariable controller. Further analysis unveils the critical controller cross coupling term that contributes to the superior performance of the multivariable controller.