Hydrogen from hydrocarbon fuels for fuel cells

Hydrogen for use in fuel cells is typically generated in a fuel processor f rom available fuels (CnHmOp) by means of the reforming reaction. In this ar ticle, we describe the reforming process, discuss the three principal pathw ays (steam reforming, partial oxidation, and autothermal reforming), and de monstrate that the process is most efficient when conducted under condition s of thermoneutrality (DeltaH(r) = 0). The reforming efficiency is correlat ed with the fuel properties to show that it depends on the values of n and m, and on the heat of formation of the fuel. Steam reforming is known to pr oduce high concentrations of hydrogen in the product. The partial oxidation and autothermal reforming processes are more attractive for practical appl ications; contrary to widely held beliefs, they are also capable of higher reforming efficiencies than are steam reformers. Crown Copyright (C) 2001 P ublished by Elsevier Science Ltd. on behalf of International Association fo r Hydrogen Energy. All rights reserved.