High Performance, Low Temperature Solid Oxide Fuel Cell Generators Utilizing a Novel Logistic Fuel Internal Reforming Stack Design

The proposed project is based on two recent exciting innovations: the direct operation of low-temperature solid oxide fuel cells (SOFCs) by direct internal reforming of liquid hydrocarbon fuels, and a novel mechanically-robust stack design that is ideally suited for small-scale (»1kW) generators. The aims of the Phase I project are to demonstrate the combination of these innovations by fabricating and testing stacks with logistic fuel, and to design a generator system based on these stack elements. The Phase I work will begin with Y-stabilized zirconia electrolyte cells, but will transition to Sc-stabilized zirconia electrolytes in order to allow reduced operating temperature. The proposed stack design provides an ideal basis for a robust kW-scale generator. The segmented-in-series cells are deposited on both sides of an insulating flattened-tube support. The tubular geometry combined with a high toughness ceramic support material, partially stabilized zirconia, provides stack elements with significantly higher mechanical strength than conventional planar SOFCs. Furthermore, it avoid significant issues with sealing and interconnection in planar designs. The stack and system design will utilize pre-Phase I and Phase I stack test results combined with state-of-the-art chemical and mass transport kinetic models. These will allow us to make key design choices along with quantifying desired system parameters, e.g. inlet and outlet temperatures, heat exchanger requirements, air cooling requirements, etc. This work will be extended in Phase II, and combined with sulfur removal from liquid hydrocarbons, new catalyst materials, new lower-temperature cell materials, and stack/system modelling to produce a prototype kW-scale solid oxide fuel cell (SOFC) stack that is ideally suited for Army applications as well as a number of commercial applications.