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Regenerative fuel cells (RFCs) as small as 1 kW can be useful on plug-in hybrid electric vehicles (PHEVs) when used to extend the range of the PHEV's battery pack. Eight hours of charging with a 1 kW RFC can double the range of a 4 kWh battery pack and would cost less than the alternative of placing an addition 4 kWh battery pack on the vehicle. Application of this approach on plug-in hybrid electric vehicles (PHEVs) is an entry position for fuel cells in the automobile market. From this entry position and the assumption of lower future fuel cell prices, an evolutionary path exists for fuel cells to decrease the price of vehicles, reduce reliance on petroleum fuels, and ultimately fully displace the use of petroleum fuels in automobiles.

Alternative fuels based on biomass have typically been specified in ways which substantially limit allowable compositions. These specifications are unlike those for petroleum based fuels which include mixtures comprised of hundreds of different compounds. Such narrow biofuel specifications are clearly disadvantageous by restricting any flexibility of using different biofuels to minimize costs and offset price fluctuations. This paper focuses on critical performance criteria for diesel fuels and provides experimental data on several, non-conventional biofuels. Experimental data includes the physical properties and ignition delay times of new, lower cost sugar formulations. The objective of this work is to develop specifications on volumetric heating value, viscosity, and ignition properties as well as other properties for compression ignition biofuels. Proposed fuel specifications would not include compositions, thereby allowing a variety of feedstocks to be used.

The Partnership for a New Generation Vehicle (PNGV) is in the midst of narrowing technology options for our new generation of automobiles, and one technology which has appeal to the major auto-makers is the use of advanced compression-ignition engines. Ford has announced that the Synergy 2010 concept car (new version of Ford Taurus) would have a 20 1 compression-ratio, compression-ignition engine with preferred fuels including gasoline, diesel, and methanol. At these conditions, cetane improvers are necessary for the optimal performance of methanol and gasoline. In general, cetane improver technology has an important role in PNGV fuels, cleaner burning diesel, and current premium diesel markets. This paper reviews published data on cetane improvers including nitrates, peroxides, amines, and soluble metal-based catalysis. In addition, methods relating cetane numbers, blending cetane numbers, and ignition delay times are reviewed.

Autoignition delay times of diesel, methanol, biodiesel, and 50 wt%, 25 wt%, and 10 wt% biodiesel in methanol were measured in a constant-volume combustor. The autoignition delay times of biodiesel are similar to diesel and confirm the utility of biodiesel as a direct diesel alternative. While methanol has poor ignition characteristics, the 50 wt% blend performed similar to diesel. The 25 wt% and 10 wt% blends had ignition delay times between those of methanol and biodiesel. Methanol and biodiesel have a synergy in blends where the favorable ignition delay times of biodiesel and lower viscosity and cost of methanol combine to provide a better fuel.