This chapter starts with a brief description of existing fuel cell technology, centralized and distributed hydrogen production, and an introduction to Pd-based membrane technology. It presents an in-depth discussion on some of the main issues related to hydrogen production from various primary fuels by employing Pd-based membrane reactors. Following this survey, the chapter discusses process intensification by focusing on issues limiting the hydrogen production rate in membrane reactors. The chapter introduces micro-structured membrane reactors that enhance heat management, reduce gas phase diffusion limitations and increase the membrane area to reactor volume ratio compared to traditional tubular reactors. Finally, it presents some examples on the performance of systems comprising Pd-based membrane fuel processor technology integrated with proton exchange membrane fuel cell (PEMFC).