Membrane reformer PEM cogeneration systems for residential applications-Part A: full load and partial load simulation

This two-part paper investigates the performances and economic potential benefits of a fuel cell cogeneration system based on a membrane reformer (MREF), using polymer electrolyte membrane (PEM) fuel cells., applied to residential cogeneration. Part A of this work focuses on the thermodynamic analysis and simulation of the system at full and partial load conditions, discussing its performance by means of a sensitivity analysis carried out under different operating conditions. Part B presents the technoeconomic analysis of the proposed system integrated into a real residential application, dealing with the energy savings and the economic balances, and proposes a preliminary design of the cogeneration unit. The system is based upon a PEM fuel cell, integrated with a membrane reformer (MREF) to form a small-scale, highly efficient cogeneration unit, potentially Suitable for application to distributed generation in the residential field. The high purity hydrogen fuel required by the PEM fuel cell is produced in the membrane reformer through hydrogen selective membranes based on a Pd-Ag alloy. The analysis is carried out aiming to define the system energy balances in all the conditions Occurring under real operation, including the influence of ambient temperature and of the expected fuel cell efficiency decay with time. The discussion reveals the relevant potential advantages of the MREF Solution with respect to fuel cell units based on steam reforming (SR) or auto-thermal reforming (ATR): when compared to these Solutions, MREF exhibits a 10% points higher electrical efficiency and requires a Much simpler plant layout. These results are the basis for the detailed system technoeconomic analysis carried out in Part B of the work. (C) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.