he main objective of this study is to design an energy recovery system for the Proton Electrolyte Membrane Fuel Cell (PEMFC) that will optimize energy use through heat integration. A PEMFC system with a power output of 5 kW was used in the case study. Methanol, which served as primary fuel source of the autothermal reformer (ATR) system, was fed together with steam and oxygen. Based on the conceptual design, the ATR product contains about 73% H2' 2% CO, and 25% C02' The hydrogen-rich reform ate produced by reforming primary fuels in the fuel proC€t::30r ystem, which scontains a significant amount of CO, was reduced further via Water Gas Shift (WGS) reactor, Tubular Ceramic Membrane (TCM), and Pressure Swing Adsorber (PSA) in series. From the plots, the pinch point was determined at 540°C,the minimum process heating requirement from hot utilities QH mon at 140 W, and the minimum process cooling requirement from cold utilities Qc. at 96 W. Furthermore, energy recovery for both heating and cooling purposes aft~; heat integration registered at 92% and 95%, respectively. Also, the number of heat exchangers reduced from 7 to 4 after heat integration.

Autothermal reformer (ATR), energy optimization, heat exchanger network (HEN) system, heat integration, proton electrolyte membrane fuel cell (PEMFC), and pinch

1. Ahmad, S., Hall, S. G., Morgan, S.W., and Parker, S. J. (2000). Practical process integration-An introduction to pinch technology, Aspen Technology, Inc.
2. Cao, Y., and Guo, Z. (2002). "Performance evaluation of an energy recovery system for fuel reforming of PEM fuel cell ower plants," J. Power Sources, 109, 2, 287–93.
3. Chu, D., and Jiang, R. (1999). "Performance of polymer electrolyte membrane fuel cell (PEMFC) stacks, Part I. Evaluation and simulation of an air-breathing PEMFC stack," J. Power Sources, 83, 1-2, 128_33.
4. De Ruyck, J., Lavric, V., Baetens, D., and Plesu. V. (2003). "Broadening the capabilities of pinch analysis through virtual heat exchanger networks," Energy Conversion & Mgt, 44, 2321-29.
5. Heizel, A., Hebling, C., Müller, M., Zedda, M., and Müller, C. (2002). "Fuel cells for low power applications," J. Power Sources, 105, 2, 148–53.
6. Linnhoff, B. (1993). “Pinch analysis--A state of-the-art overview," Trans. IchemE, 71, A, 503–22.
7. Mizsey, P., Newson, E., Truong, T. H., and Hottinger, P. (2001). "The kinetic of methanol decomposition: A part of autothermal partial oxidation to produce hydrogen foe fuel cells,” Applied Catalyst, A-General, 213, 233-37.
8. Riensche, E., Meusinger, J., Stimming , U., and Unverz, G. (1998). "Optimization of a 200-kW SOFC cogeneration power plant, Part II: Variation of the flow sheet," J. Power Sources, 71, 306-14.
9. Zalc, J. M., and Löffler, D. G. (2002). "Fuel processing for PEM fuel cells: Transport and kinetic issues of system design," J. Power Sources, 111, 1, 58-64.