(98a) Stack Fueling Perspectives (Keynote)

Fuel cell power systems are an attractive solution for future portable and stationary power sources in many applications such as shipboard, military base, remote sites, and truck APU.  These fuel cell stacks have primarily been operated with synthetic fuels or with stored H₂.  It has become increasingly apparent that a lack of fueling solutions utilizing practical fuels has limited the migration of fuel cells to field applications.  In developing practical fuel cell-based power generators, durability of reforming systems to safely supply hydrogen in-situ and to permit stable, coke-free fuel cell stack operation via catalytic reforming of commonly available fuels is crucial.  The use of practical liquid fuels includes distillate fuels such as diesel or kerosene, as well as renewable fuels such as bio-fuels.  Making these fuels suitable for use in the fuel cell stacks include reformation of the fuels such as to minimize higher hydrocarbon content in the reformate to an acceptable level (depending on the fuel cell type), sulfur cleanup to <<1 ppm, and low parasitic losses.  Additionally, water neutrality is an essential component of these systems.  This requires sufficient water recovery and separation from the anode exhaust.  The ability to achieve all of these objectives requires accurate flow management, thermal management, and robust control algorithms.

Efforts to develop and optimize practical fueling solutions for different fuel cell stacks will be discussed.  These solutions include integrated reformer systems. Topics such as fuel flexibility (gaseous and liquid fuels, biofuels), sulfur tolerance (e.g., with distillate and logistic fuels), water neutrality, BOP development (e.g., pumps, sensors, heat exchangers) and control protocols will be briefly reviewed.  Reformer and stack performance data will be shared.  Recent advances in H₂ production, pre-reforming and partial oxidation approaches will also be briefly highlighted. The goal will be to provide insights into Fuel Cell fueling initiatives and corresponding system design approaches.