Reformer with an Hydrocarbon absorber

A fuel reformer for use with a fuel cell system is combined with an absorber to absorb unreacted hydrocarbon fuel at a first temperature and release the unreacted hydrocarbon fuel at a second temperature, and subsequent burning of the unreacted hydrocarbon in a burner downstream. The absorber, such as a zeolite, is effective to increase efficiency of the reformer and fuel cell especially under low temperature or start-up conditions.