Start-up characteristics of segmented-in-series tubular SOFC power modules improved by catalytic combustion at cathodes

For large-scale SOFC power generation systems, a shorter start-up time of SOFC cell stacks with relatively large heat capacity is one of the most important technological issues to determine the flexibility in SOFC system operation. In this study, start-up procedures have been examined to shorten the start-up time period. The conventional heating procedure using pre-heated hot air and self-heating by SOFC operation at low temperatures had a difficulty to shorten the start-up time period because of the limitation in power generation at lower temperatures. In this study, as an alternative start-up procedure, catalytic combustion at the SOFC cathodes is, for the first time, demonstrated to be useful on the system level. The applicability of the catalytic combustion to shorten the start-up time period has been verified numerically as well as experimentally by using a large-scale cell stack cartridge. This unique start-up procedure enables to operate SOFC-based large-scale power generation systems.