On-board fuel processor

For the calculation of WTW energy requirements and GHG emissions we have made the simplification that the fuel consumption of a vehicle fuelled with ethanol (e.g., E85) is the same as that of a vehicle fuelled with pure gasoline. Methanol is used in fuel cell vehicles with on-board fuel processors. Table 7.2 shows the properties of different transportation fuels. 

Methanol has been considered as a fuel for fuel-cell vehicles with on-board fuel processors for some time. Dimethyl ether (DME) has been suggested as a fuel alternative for diesel engines in Japan and Sweden. The synthesis of DME is based on methanol synthesis followed by DME formation ... 

All fuel cells for use in vehicles are based on proton-exchange-membrane fuel cell (PEMFC) technology. The methanol fuel-processor fuel cell (FPFC) vehicle comprises an on-board fuel processor with downstream PEMFC. On-board methanol reforming was a development focus of industry for a number of years until around 2002. Direct-methanol fuel cells (DMFC) are no longer considered for the propulsion of commercial vehicles in the industry (see also Chapter 13). 

FAME FAO FBR FC FCV FFV FOB FPFC Fatty acid methyl ester Food and Agriculture Organization of the United Nations Fast-breeder reactor Fuel cell Fuel-cell vehicle Flexible-fuel vehicle Free on board Fuel-processor fuel cell... 

Argonne National Laboratory has developed a POX reformer suitable for use in vehicles. The U.S. Department of Energy (DOE) supports work on POX systems for on-board fuel processors for fuel cell vehicles through the Office of Transportation Technologies Fuel Cell Program.17... 

As stated earlier, an increased interest is currently being concentrated on smaller-scale hydrogen production for fuel cell applications ranging from industrial to residential and mobile implementations. An especially important emphasis has been placed on the design of on-board fuel processors capable of generating the hydrogen necessary to power vehicles. Another application of the mobile fuel processor under development is the portable processor/fuel cell system capable of powering electronic devices with liquid hydrocarbon fuels, as replacement for batteries.24 26... 

In recent years, the interest toward PM catalysts has grown from essentially academic to much more practical, as a result of efforts to develop on-board fuel processors for cars. Operational conditions envisaged for such fuel processors preclude the existing Cu-Zn-Al catalysts from being applicable, while PM catalysts are believed to be a viable candidate. Platinum-based catalysts with a great variety of promoters, modifiers, and supports, as well as their preparation conditions seem to be most widely explored in research papers and patent applications. Pt supported on ceria containing support materials have been widely explored for the WGS reaction. - ... 

An alternative to using a direct H2 fuel supply is to refuel a vehicle with a carbon-based fuel such as methanol, and use an on-board fuel processor to transform it into H2. This process has the disadvantage of generating by-products CO and/or CO2 and N2 or NO (see Box 14.8). Thus, the vehicle is classed as reduced-emission rather than zero-emission. An advantage of using an indirect, rather than direct, H2 supply is that there is no longer a need to provide hydrogen-fuel stations. As a consequence, infrastructure costs are reduced. 

Table 9.1 US Departments of Energy technical targets for an on-board fuel processor [448].

Figure 9.48 Fuel cell vehicle with on-board fuel processor developed by Toyota [447].

Tank-to-wheels efficiency Fuel ceU systems use less energy than conventional power trains, because of the intrinsic high efficiency of the stacks. Hydrogen-based FCVs exhibit significantly higher fuel economy than those employing on-board fuel processors. 

FIGURE 6.11 Fuel attributes for good on-board fuel processor operation. NOTE RVP = vapor pressure. 

BIOFEAT - Development of a biodiesel processor for an on-board fuel cell APU. The expected result is a fully tested modular 10 kW biodiesel fuel processor for an SOFC or PEM APU for a vehicle. 

Where fuel cell systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For transportation applications, the process water must be recovered from the fuel cell system exhaust gas. For such... 

A fast-start capability is a key requirement for a compact fuel processor, especially crucial for specific cases such as on-board automotive application. A possible means for the fast start-up of an ATR reactor is starting by feeding to the reactor a mixture with an O2 C molar ratio typical of a rich combustion. The goal of this mode is to raise the reactor temperature quickly and simultaneously avoid catalyst oxidation. Then the reactor will move to the ATR mode through the addition of steam and by decreasing the 02 C feed ratio to the desired value. 

General Motors has collaborated with ExxonMobil to develop an on-board gasoline fuel processor in the late 1990s and early 2000s. 

UTC Fuel Cells has partnered with Nissan and Shell Hydrogen to develop a 50-kW on-board gasoline fuel processor with a volume of 78 L and weight of 65kg. The start-up time is 3.5min.8... 

On the other hand, the use of a fuel processor on-board of a vehicle makes it too complex for a practical commercialization in the automotive field, independently on carbon emissions associated to utilization of not renewable fuels. 

Nuvera is working with the Department of Energy to develop efficient, low emission, on-board multi-fuel processors for the transportation application. The fuels include gasoline, methanol, ethanol, and natural gas. 

Real-time switching between gasoline and diesel fuel could actually be demonstrated at different load levels without any apparent change to the performance of the system 621). However, low sulfur fuels were utilised exclusively. The fuel processor was tested in combination with an Andromeda fuel cell stack developed by Nuvera. No apparent difference could be observed when operating the combined system with ethanol, gasoline or diesel fuel [621]. However, recent activities of these workers have been directed towards a lOkWd on-board power plant or auxiliary power unit [621]. 

The technology of choice for on-board electric power on mid-length space vehicle missions (several days to a year), including the important man-moon mission, was the fuel cell. This was because the use of batteries for more than a couple of days proved too heavy, combustion engines and gas turbines required too heavy a fuel supply, and the use of a nuclear reactor was only suitable for missions of a year or more. There was a simple choice of fuel for space fuel cells it was hydrogen because it doesn t require a fuel processor other than storage and pressurization, it is relatively lightweight when stored under pressure, and it was the best fuel for the early-developed alkaline fuel cell. Fuel flexibility was not an issue. 

The control strategies are programmed in Matlab-Simulink, compiled in C-H-and then downloaded into the DSP processor of the d-Space board. The controlled management of the fuel cell system during the dynamic tests operates on hydrogen purge, air flow rate regulation (stoichiometric ratio), external humidification, and stack temperature. 

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