Tighter environmental regulations and more heavy-end upgrading in the petroleum industry lead to increased demand for hydrogen in oil refineries. In this paper, a systematic methodology is proposed to select appropriate purifiers from pressure swing adsorption processes, membranes or hybrid systems for recovering hydrogen from refinery off-gases. Through the understanding of the trade-offs between hydrogen saving, compression costs and capital investment, a superstructure is built to include possible purification scenarios. The shortcut models for different purification units are developed via the insights of the processes. The recovery rate of purifiers is also modelled to optimize process parameters. This method achieves the optimal design for overall hydrogen networks at a conceptual level.