Regenerative, coal-based solid oxide fuel cell-electrolyzers

Abstract

In this paper we theoretically analyze the concept of a reversible-and-regenerative solid oxide device comprising a multilayer architecture that will employ an oxygen-ion-conducting solid oxide, e.g. yttria-stabilized zirconia (YSZ) as the electrolyte. The two electrodes to be used in the device are reversible, i.e. capable of reversibly operating as the cathode and as the anode. One of the electrodes to be used is a liquid metal Ag and the other electrode will be chosen from several options including a nickel (Ni)–YSZ porous cermet. The advantage of such a device is the ability to use coal (carbon), an abundantly available fuel in a solid oxide fuel cell. The device can be operated in an electrolysis mode to generate hydrogen from coal and steam and in a power generation mode as a solid oxide fuel cell to generate electricity from the hydrogen generated during the electrolysis cycles.