This paper focuses on the design of a controller for a low temperature ethanol steam reformer for the production of hydrogen to feed a protonic exchange membrane (PEM) fuel cell. It describes different control structures for the reformer and treats the control structure selection of this multiple input multiple output (MIMO) system. For each considered control structure, decentralised 2 2 controllers with proportional integral (PI) control actions in each control loop are implemented. The tuning of the PI parameters and the performance evaluation of the different controllers are based on a non-linear simulation model. For the validation and comparison of the considered controllers, the dynamic response for different setpoint changes and initial conditions is analysed, as well as the behaviour of the controlled system against disturbances.