Transportation fuel cell demonstrations

Fuel cells have moved remarkably quickly from laboratory to road testing. The City of Los Angeles, California, USA, recently leased the first of five Honda FCX models as part of a demonstration program designed to generate real road data. And, DaimlerChrysler is currently testing 60 Mercedes-Benz F-Cell A-Class fuel cell vehicles with demonstration partners under everyday conditions. 

A number of the major automakers have stated their intention to begin selling - or expanding sales of - fuel cell passenger vehicles. Toyota plans to offer about 20 hybrid fuel cell SUVs based on its Highlander platform. Nissan has announced plans to start selling a fuel cell vehicle, and Ford Motor Company said it would offer a fuel cell version of the Focus in low-volume production for small fleet operations. Other FCVs include the CM Opel HydroCen 3, the Hyundai Santa Fe FCEV, and the Nissan Xterra FCV, the DaimlerChrysler Necar 5, and Daihatsu s Move FCV-K-2. 

Another important area is the use auxiliary power systems (AFU), which are expected to be one of the first niche applications for fuel cells in the transport area. Auxiliary power today represents a significant portion of the power needs for transportation. Developments of AFUs may also have an impact in the stationary area. 

Despite these amazing developments, time is still needed to prove and demonstrate low-cost, easy-to-manufacture designs and ancillary systems. It is expected that it will take several production cycles at low-to-medium volumes to gain experience, establish reliability, and achieve maturity. Over the next decade, automakers may be unwilling to commit to extensive production, since early designs could become obsolete before costs are fully recovered. The following section describes current 

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Recently, the major activity in transportation fuel cell development has focused on the polymer electrolyte fuel cell (PEFC). In 1993, Ballard Power Systems (Burnaby, British Columbia, Canada) demonstrated a 10 m (32 foot) light-duty transit bus with a 120 kW fuel cell system, followed by a 200 kW, 12 meter (40 foot) heavy-duty transit bus in 1995 (26). These buses use no traction batteries. They operate on compressed hydrogen as the on-board fuel. In 1997, Ballard provided 205 kW (275 HP) PEFC units for a small fleet of hydrogen-fueled, full-size transit buses for demonstrations in Chicago, Illinois, and Vancouver, British Columbia. Working... 

In the above expression, the first term represents the accumulation and convective transport of enthalpy, where is the heat capacity of phase k. The second term is energy due to reversible work. For condensed phases this term is negligible, and an order-of-magnitude analysis for ideal gases with the expected pressure drop in a fuel cell demonstrates that this term is negligible compared to the others therefore, it is ignored in all of the models. 

Fuel Cells are taken up in Section 1, which begins with a brief overview of fuel cell fundamentals and a synopsis of each of the major fuel cell types. It then provides a review of lEA government work as it relates to each fuel cell type, including R D efforts directed as specific fuel cell types a review of programs undertaking basic fuel cell R D and, the section concludes with a review of fuel cell demonstrations for transportation and stationary applications. 

Transportation PEMFC Hybrid (Ni-MH + fuel cell) FCV (2002) FCV (75 kW fuel cell) demonstration (2002)... 

Although natural gas feedstock currently is preferred by some demonstration plants, alternative fuels, such as light distillates, coal gas. and fuel-grade methanol may be used. Methanol can be steam reformed at relatively low temperatures and. for this reason, can be adapted to smaller, transportable fuel-cell power plants of the type desired for certain military and commercial gear. 

Additionally, in the near future, SECO will execute its first fuel cell project, the Texas LPG Fuel Processor Development and Fuel Cell Demonstration Program. The SECO led program, which was funded imder a competitive U.S. Department of Energy grant process, is a partnership of private and public entities including the Alternative Fuels Research and Education Division of the Railroad Commission of Texas Plug Power, Inc. UOP/HyRadix, Des Plaines, Illinois Southwest Research Institute the Texas Commission on Environmental Quality and the Texas Department of Transportation. ... 

In terms of demonstration and technology dissemination. Table 7.7 highlights the main medium-term targets for both stationary and transportation fuel cells. 

There is a major potential for energy conservation in transportation, by increasing the energy efficiency of automobiles. The recent commercialization of hybrid vehicles, which combine electric and gasoline motors, demonstrates how much more efficient automobile transport can be. Hybrid power systems deliver double the fuel efficiency of conventional engines. Moreover, as fuel cells are perfected, even greater energy efficiencies may be achieved. 

The PEMFC is technically in quite an advanced status. Fuel cell systems for both transport as well as stationary applications exist in a wide variety and are being operated in demonstration programs under practical conditions [57]. For large-scale market introduction, cost has to be reduced significantly, and durability must be improved. Both items cannot be solved by clever engineering only -new materials are also required. 

This edition of the Fuel Cell Handbook is more comprehensive than previous versions in that it includes several changes. First, calculation examples for fuel cells are included for the wide variety of possible applications. This includes transportation and auxiliary power applications for the first time. In addition, the handbook includes a separate section on alkaline fuel cells. The intermediate temperature solid-state fuel cell section is being developed. In this edition, hybrids are also included as a separate section for the first time. Hybrids are some of the most efficient power plants ever conceived and are actually being demonstrated. Finally, an updated list of fuel cell URLs is included in the Appendix and an updated index assists the reader in locating specific information quickly. 

Early expectations of very low emissions and relatively high efficiencies have been met in power plants with each type of fuel cell. Fuel flexibility has been demonstrated using natural gas, propane, landfill gas, anaerobic digester gas, military logistic fuels, and coal gas, greatly expanding market opportunities. Transportation markets worldwide have shown remarkable interest in fuel cells nearly every major vehicle manufacturer in the U.S., Europe, and the Far East is supporting development. 

There has been an accelerated interest in polymer electrolyte fuel cells within the last few years, which has led to improvements in both cost and performance. Development has reached the point where motive power applications appear achievable at an acceptable cost for commercial markets. Noticeable accomplishments in the technology, which have been published, have been made at Ballard Power Systems. PEFC operation at ambient pressure has been validated for over 25,000 hours with a six-cell stack without forced air flow, humidification, or active cooling (17). Complete fuel cell systems have been demonstrated for a number of transportation applications including public transit buses and passenger automobiles. Recent development has focused on cost reduction and high volume manufacture for the catalyst, membranes, and bipolar plates. 

For this type of fuel cell, a number of reports studying anode MPLs have been published. Neergat and Shukla [124] used a hydrophobic MPL on the cathode (carbon black and PTFE) and a hydrophilic MPL on the anode (carbon black and Nafion) (see Section 4.3.2). Different types of carbon particles were used (Vulcan XC-72, acetylene black, and Ketjenblack) and it was concluded that Ketjenblack was the carbon that showed the best performance when it was used on both the anode and cathode MPLs with 10 wt% Nafion and 10 wt% PTFE, respectively. A similar design was also used by Ren et al. [173] in a passive DMFC. Improvement of the DMFC performance by using a hydrophilic MPL, as discussed previously, was also demonstrated by Lindermeir et al. [125]. They compared both hydrophilic and hydrophobic MPLs for the anode DL, and it was observed that the former improves the mass transport of the MEA. 

Prasarma et al. [185] were also able to observe an optimum thickness of DLs for fuel cells experimentally. They demonstrated that the thicker DLs experience severe flooding at intermediate current densities (i.e., ohmic region) due to low gas permeation and to possible condensation of water in the pores as the thickness of the DL increases. On the other hand, as the thickness of the DL decreases, the mass transport losses, contact resistance, and mechanical weakness increase significantly [113,185]. Through the use of mathematical modeling, different research groups have reported similar conclusions regarding the effect of DL thickness on fuel cell performance [186-189]. 

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