Effects of fuel cell anode recycle on catalytic fuel reforming

• Published in: Journal of power sources 2007-06, Vol.168 (2), p.477-483
• Main Authors: Shekhawat, Dushyant, Berry, David A., Gardner, Todd H., Haynes, Daniel J., Spivey, James J.
• Format: Article
• Language: English
• Subjects: Anode recycle; Applied sciences; Auxiliary power unit; Carbon formation; Diesel reforming; Energy; ENERGY PLANNING, POLICY, AND ECONOMY; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Reformer recycle; Solid oxide fuel cell; Solid oxide fuel cell, Anode recycle, Reformer recycle, Carbon formation, Auxiliary power unit, Diesel reforming
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2007.03.031

The presence of steam in the reactant gas of a catalytic fuel reformer decreases the formation of carbon, minimizing catalyst deactivation. However, the operation of the reformer without supplemental water reduces the size, weight, cost, and overall complexity of the system. The work presented here examines experimentally two options for adding steam to the reformer inlet: (I) recycle of a simulated fuel cell anode exit gas (comprised of mainly CO 2, H 2O, and N 2 and some H 2 and CO) and (II) recycle of the reformate from the reformer exit back to the reformer inlet (mainly comprised of H 2, CO, and N 2 and some H 2O and CO 2). As expected, anode gas recycle reduced the carbon formation and increased the hydrogen concentration in the reformate. However, reformer recycle was not as effective due principally to the lower water content in the reformate compared to the anode gas. In fact, reformate recycle showed slightly increased carbon formation compared to no recycle. In an attempt to understand the effects of individual gases in these recycle streams (H 2, CO, CO 2, N 2, and H 2O), individual gas species were independently introduced to the reformer feed.