Automotive Auxiliary Power Units Research Articles

A micro-structured 5kW complete fuel processor for iso-octane as hydrogen supply system for mobile auxiliary power unitsPart II—Development of water–gas shift and preferential oxidation catalysts reactors and assembly of the fuel processor

Abstract Microstructured reactors for water–gas shift and the preferential oxidation of carbon monoxide were developed for a fuel processing/fuel cell system running on iso-octane and designed for an electrical power output of 5 kWel. The target application was an automotive auxiliary power unit (APU). The work covered both catalyst and reactor development. A platinum/ceria catalyst was applied for water–gas shift, while platinum on zeolite/alumina carrier served as catalyst for preferential oxidation. These catalysts were introduced into the final full size prototype reactors, which were constructed from microstructured stainless steel foils. Testing in a pilot scale test rig revealed conversion close to the thermodynamic equilibrium for the water–gas shift reactors at a WHSV range of 17–41 Ndm3/(h gcat). The preferential oxidation, which was performed at higher WHSV in the range of 48–98 Ndm3/(h gcat) revealed up to 90% conversion in a first stage, while in the second stage reactor the carbon monoxide content of the reformate was decreased to less than 50 ppm. The reactors were then incorporated into a complete bread-board fuel processor of 5 kWel power equivalent, which comprised also of an autothermal reformer reactor. The fuel processor was operated at a steam to carbon ratio of 3.3 and an oxygen to carbon ratio of 0.67. Under these conditions, it converted the iso-octane feed completely to purified reformate with an overall efficiency of 74%.

A micro-structured 5kW complete fuel processor for iso-octane as hydrogen supply system for mobile auxiliary power unitsPart I. Development of autothermal reforming catalyst and reactor

A micro-structured autothermal reformer was developed for a fuel processing/fuel cell system running on iso-octane and designed for an electrical power output of 5 kWel. The target application was an automotive auxiliary power unit (APU). The work covered both catalyst and reactor development. In fixed bed screening, nickel and rhodium were identified as the best candidates for autothermal reforming of gasoline. Under higher feed flow rates applied in microchannel testing, a catalyst formulation containing 1 wt.% Rh on alumina prepared by the sol–gel synthesis route proved to be stable at least in the medium term. This catalyst was introduced into the final prototype reactor designed to supply a 5 kW fuel cell, which was based upon micro-structured stainless steel foils. The reactor was optimised for equipartition of flows by numerical simulation. Testing in a pilot scale test rig, which was limited to a specified power equivalent of 3.5 kWel, revealed more than 97% conversion of gasoline at 124 Ndm3/min total flow-rate of reformate, which corresponded to a WHSV of 316.5 Ndm3/(h gcat).

Progress in solid oxide fuel cell materials

Solid oxide fuel cells (SOFCs) are advancing steadily as materials become more widely available, as cell stacking techniques develop, as operational issues such as rapid start-up are addressed and as applications become more focused. The present study reviews recent developments in SOFC materials, positioning them in the context of historical trends and future ambitions for fuel cell technologies. The conclusion is that materials are starting to become widely available, cells are being traded in larger numbers, stacks can be obtained but are still relatively costly, and systems may be operated in agreement with application companies. Devices are being aimed at sensor products, through automotive auxiliary power units (APUs) to portable combined heat and power units, to stationary power plants in buildings and pressurised hybrids up to 1 MWe.

03/01753 Solid oxide fuel cells for direct oxidation of liquid hydrocarbon fuels in automotive auxiliary power units: sulfur tolerance and operation on gasoline: Crosbie, G. M. et al. Society of Automotive Engineers, /Special Publication] SP, 2002,1691, 119–126

03/01753 Solid oxide fuel cells for direct oxidation of liquid hydrocarbon fuels in automotive auxiliary power units: sulfur tolerance and operation on gasoline: Crosbie, G. M. et al. Society of Automotive Engineers, /Special Publication] SP, 2002,1691, 119–126

Solid Oxide Fuel Cells for Direct Oxidation of Liquid Hydrocarbon Fuels in Automotive Auxiliary Power Units: Sulfur Tolerance and Operation on Gasoline

AbstractFor Abstract see ChemInform Abstract in Full Text.

ChemInform Abstract: Application of Direct Oxidation of Liquid Hydrocarbon Fuels in Solid Oxide Fuel Cells to Automotive Auxiliary Power Units.

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