Demonstration of LPG-fueled solid oxide fuel cell systems

The technology of reforming liquefied petroleum gas (LPG) to produce a mixture of methane, hydrogen and carbon oxides for application to internal reforming SOFC stacks was developed from experimental studies in a microreactor and then scaled-up and demonstrated through a planned 500-h test in a prototype LPG reformer. A number of pre-reforming and steam reforming catalysts were tested in the microreactor under isothermal conditions. The aim was to evaluate their activity for LPG reforming under thermodynamically favourable conditions. Compositions of the exit-gas from the reformer were measured for a range of steam-to-carbon (S/C) ratios and operating temperatures. Promising catalysts from these tests were then tested in a 1-kW size prototype reformer under adiabatic conditions with the temperature in the catalyst bed ranging from 350 to 373 °C at selected steam-to-carbon ratios. With a steam/carbon ratio of 1.5 under these conditions, the composition of the reformed gas on a dry-basis is 55% methane, 25% hydrogen and 20% carbon dioxide. The technical viability of operating SOFC stacks on pre-reformed LPG was firstly demonstrated by operation of a single cell on simulated pre-reformed LPG. Finally, operation of an internal reforming SOFC system fueled by commercial LPG was demonstrated by running a 1-kW, 2×2 array stack in a 5-kW size SOFC system.