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Advanced Fuel Cell Technology
©2011 Seven Mountains Scientific
ISSN: 1095-1415

meeting report

The 2005 Fuel Cell Seminar

Palm Springs, CA USA

November 14-18, 2005

See photos

• by Dennis Sieminski, P.E.

The 2005 Fuel Cell Seminar held at the Convention Center in Palm Springs, California, November 14-18 was well attended by more than 2,400 participants and 117 exhibiting companies. The conference continues to be an excellent event for those engaged in all aspects of the fuel cell industry since it brings together those involved in the full spectrum of types, sizes, and applications for fuel cells and representing the cross section of participating organizations from commercial companies, to government agencies, and academic institutions. Plus, the conference offers a variety of ways to access technology and business information ranging from a vendor exhibition area, a program of technical presentations, poster sessions, a series of educational courses and, of course, the opportunity to network and meet directly with the people involved in the technology at various receptions.

Technical Program Overview

The program for the technical presentations was divided into three tracks: High-Temperature Fuel Cells, Low-Temperature Fuel Cells, and Applications. The High Temperature was devoted almost exclusively to solid oxide fuel cells (SOFC) with the poster sessions providing some presentations on molten carbonate (MCFC) which is best suited for primary stationary power for 100kW to multi MW, and phosphoric acid (PAFC) posters. The Low Temperature section covered polymer electrolyte membrane fuel cells (PEM FC) and direct methanol fuel cells (DMFC). The Applications session covered on-going development programs and experience with fuel cells for power plants, residential electricity and heat, mobile fuel cells for transportation, distributed generation for and backup power for telecom, and critical services like hospitals and financial data centers, and portable power for electronic devices, like laptop computers. While each application had its own driving benefit, whether improved air quality in transportation or energy density in portable applications, they all had the common thread of cost as a major obstacle. The strongest inducement for acceptance of fuel cells into each of the applications will be reaching a price that is compelling against the existing power solutions being used today.

Plenary Session – Fuel Cells and Transportation

The opening plenary session featured an award to Dr. Alan Lloyd of the California Environmental Protection Agency, who was recognized for his work on zero emission vehicle legislation and chairing the California Fuel Cell Partnership.

Byron McCormick, executive director of fuel cell activities for General Motors, provided a view of the company’s fuel cell program. Noting all the recent interest and publicity in hybrids, McCormick made it clear that GM still sees fuel cells as the real end game for a number of fundamental reasons. GM’s strength is selling style and utility. Fuel cells with a single power source and electric drivetrain allow that. Existing technologies with their multiple engine and transmission combinations require an emphasis on array of technical components and require a lot of compromises in packaging. The GM skateboard concept is an example of the freedom that designers will have in a fuel cell platform. Most importantly hybrids, while highly fuel-efficient, still do not resolve the oil dependence and emissions issues which can only be fully satisfied in a hydrogen-based transportation system.

Addressing the same topic of fuel cells in transportation was Russ Bosch, chief engineer at Delphi for solid oxide fuel cells (SOFC). He provided some perspective on the present state of the car industry’s struggle to change its reliance on the internal combustion engine (ICE) by looking at the last major change in power in transportation – from animals to engines at the turn of the previous century. There was no fuel infrastructure at that time and there were many competing power technologies in steam and electric. In this environment, it took 20 years to sort out all the issues before manufacturers were whittled down to a small number with clear technology winners. Delphi is looking at SOFC as one of a number of technologies. One of the strongest points being – it can work with a number of current fuels that do not have the same generation, distribution, and storage issues as hydrogen. Plus, the lower number of parts helps reduce cost and contribute to reliability. The other challenge facing the fuel cell business is more financial than technical. At this point the business is primarily R&D and a large amount of capital is needed. Venture capital and traditional business borrowing and investment are not sufficient. The government has a role to play in stimulating the early adopter market and providing development incentives.

Plenary Session – Fuel Cell Investing

As a mark of the importance of the economic aspect of the transition to a fuel cell world, one of the plenary sessions was devoted to the financial and business side of the fuel cell industry dealing with topics on investment. The messages that came out of the talks here are that the government has a pivotal role to play in the transition because market forces for reducing emissions and oil imports are not sufficient to overturn the existing infrastructure in a short time frame. Companies should not be under any illusions and must realize their fuel cell products will be purchased primarily on cost. The business structure and model of fuel cell companies needs to incorporate a long R&D phase and an early adopter marketing approach.

Information from Papers and the Exhibition Floor

Simulation tools for fuel cells. Finite element analysis (FEA), computational fluid dynamics (CFD) and various mathematical techniques based on partial differential equations are being used to model various physical phenomena in fuel cells – distribution of fuel and oxygen to the stack, thermal gradients, thermal distribution for design of heat transfer and cooling, thermally induced stresses, water condensation and flooding that prevent proper gas transport, and current and voltage distribution. Gary McVay of Pacific Northwest National Lab (PNNL), says solid oxide fuel cell development works on developing modeling tools. Modeling can “build, test, break, and fix” virtual fuel cells and provide insight into what is often a very complex relationship among a number of nonlinear parameters like flow, temperature, geometry, and mechanical components. The University of South Carolina’s Engineering College and Information Technology’s Department of Chemical Engineering have developed subroutines for modeling physical phenomena in fuel cells.

Proton exchange membrane development. Fluorocarbon PEMs now have competition from hydrocarbon and composite variations of PEMs for DMFC and automotive PEM FCs. While there are gains and improvements in some metrics, targets for durability and cost in automotive where their success is absolutely critical remain a distant 3-5 times away for all approaches so far. The following is an overview of some of the main participants in PEM technology:

DuPont. The long-time producer of the Nafion PEM and Gen IV MEAs for DMFCs and hydrogen based PEM FCs reports a 20% increase in power density with less catalyst loading, and a two-time increase in durability. Fluoride ion release and membrane thinning are common measures of membrane chemical attack and are used for durability indicators.

W.L. Gore. Dry reactant, high temperature operation, low catalyst loading, duty cycle power transients, start up/shut down, and freeze tolerance are the edges of the performance envelope that PEMs must satisfy. Durability failure for fluorocarbon PEMs can be broken down into two categories: mechanical and chemical degradation of the ionomer. Ionomer membranes swell in x y z direction in response to RH changes, and with the membrane constrained stresses result. Adding reinforcing materials are one strategy being tried and new membranes show a five-time improvement in certain life tests. Temperature, pressure and low RH contribute to ionomer chemical gradation. Materials tested in these aggressive conditions allow promising candidates to be identified. Some accelerated testing schemes have been developed like carbon corrosion testing conducted by holding the cathode at 1.4V versus RHE and measuring the CO ₂ evolved in the electrochemical active area. Similarly Pt dissolution and sintering accelerated tests help identify mechanisms and guide material development.

3M. Durability is affected by surface area loss of the Pt catalyst which can be from support corrosion, Pt dissolution, oxidation, or agglomeration due to high voltage excursions of the electrode during start-stop cycling or momentary fuel blockage by water which can be critical in Pt oxide film formation. 3M has shown promising results with nano-structured thin film (NSTF) catalyst electrodes which are much more resistant than conventional Pt on carbon

Hydrocarbon PEM at PolyFuel. Jim Balcom, CEO, has tuned up the development and prototype delivery machine at PolyFuel. Investing in fabrication and test hardware and putting in place a formulate-test-modify process that is designed to quickly feed back lessons learned and squeeze every ounce of time out of the R&D cycle, he has sampled all the major players involved in portable FCs with names like Sony, Sanyo, Toshiba, Samsung, LG. Among the benefits of PolyFuel’s hydrocarbon PEMs versus fluorocarbon type membranes are: lower cost, less catalyst, longer runtimes, and less water recovery. In automotive, hydrocarbon membranes are working towards performance parity in durability with fluorocarbon PEMs while offering the enticement of an extreme cost advantage of $1300/car in the 10K cars/year production and a $200/car benefit at a 35K annual vehicle production number.

PEM with aromatic structure and sulfone ion exchange substrate. Honda claims its own proprietary PEM in its FCX fuel cell vehicle has a chemical structure consisting of a main chain with an aromatic structure and a sulfone ion exchange substrate. The aromatic structure provides high thermal stability and durability. Contrast this with fluorinated electrolyte membranes which become soft and deform at high temperatures. The sulfone has very high ionic conductivity which is what supposedly allows their low temperature operation (-20°C).

Kynar polyelectrolyte PEM composite. Arkema, Johanson Matthey, and Nissan have teamed up on a PEM composite consisting of Kynar PVDF (polyvinylidene fluoride) for mechanical strength and chemical resistance blended with a polyelectrolyte to provide the necessary proton conductivity to allow a more tailored approach. They are demonstrating superiority in some specific properties, e.g., gas barrier properties and dry tear, but still need to find the right recipe for success in others.

Single wall nano tube (SWNTs). Also known as Buckytubes, SWNTs for PEMFC and DMFC are being explored by Carbon Nanotechnologies, Motorola, and Johnson Matthey Fuel Cells. Benefits of the material are high surface area, electrical conductivity, mechanical strength, and potential for proton conductivity which allow tough, thin porous mats with high thermal conductivity. The expectation is that corrosion of the catalyst support in conventional PEM FCs can be overcome because the SWNTs do not have the edge planes of graphitic sheets.

Nano-porous proton-conducting membrane. Green Fuel Cell of Israel claims a nano-porous proton-conducting membrane with a cost today of $40/m²that delivers 200mW in a DMFC and is a solution to water management. High temperature polymer polybenzimidazole (PBI) is being supplied by PEMEAS of Germany (formerly Celanese Ventures GmbH) as a PEM for Plug Power’s high temperature (160°C) PEM FC.

Fuel Cells for Automotive

The fuel cell vehicles on display and available for test drive at the conference seemed showroom ready. You would not have the first idea from the ride, appearance, and performance that buying one may be 15 to 20 years off into the future. While the fleet of vehicles fielded by the auto companies represents a major milestone (there are about 600-800 under trial across the globe) a number of challenging obstacles remain: on board fuel storage must be doubled to achieve an acceptable driving range, power plant lifetime improvement must increase five times, fuel cell drive train cost must be cut to 10% of current costs, and a clean hydrogen generating and distribution infrastructure must replace the existing well established global network of gas stations. The benefits to the country and world of significantly improved air quality and reduced dependence on dwindling oil reserves (60% of annual oil consumption in the U.S. goes to automobiles) are the compelling reasons that keep development resources flowing.

FCV vs HEVs vs ICEs. H2Gen Innovations prepared a green house gas emissions (GHG) and gasoline consumption computer simulation for 100 years comparing business as usual, with gas-powered hybrid electric vehicles (HEVs), hydrogen FC, (H2 FCVs) and hydrogen internal combustion engines (H22 ICE). According to the simulation, the only long-term solution to the dual problem of reduced GHGs and imported oil is hydrogen-powered vehicles. Where would the H2 come from? Transitioning from a gasoline economy could come via reforming ethanol at local filling stations which would provide hydrogen at about $2.02 per gallon of gasoline equivalent (untaxed) compared to $1.62 gas cost today (untaxed). See Figure 3showing hydrogen from corn ethanol at the same cost as gasoline with half the GHG, and cellulosic ethanol at less than today’s gas cost with an 80% reduction of GHGs. Eventually the transition would be complete going to H2 from renewable energy. But what renewable energy source makes sense? The projection shows electrolyzing water with renewable energy (photovoltaic, wind) is actually not a good choice for displacing coal-based grid electricity. Ethanol is more effective in reducing GHGs than making H2 for cars.

A Comparison of On-board Hydrogen Storage Methods for Vehicles. A comparison of the volume, weight and well-to-wheel efficiency of three proposed systems of on-board fuel storage – compressed H2, Metal Hydrides, and DME reforming – was offered by a group led by Mitsubishi Heavy Industries. A well-conceived graphical presentation helps to capsulize the issues. Assume effective H2 storage of 5.8kg is the same for all.

Honda FCX. Formerly Honda used Ballard’s fuel cell stack in its 2003 and 2004 fuel cell vehicles. The FCX 2005 has Honda’s own fuel cell stack rated at 78kW or 104hp. It uses a proprietary PEM with good low temperature conductivity, allowing startup at -20°C. Graphite bipolar plates are replaced with stainless steel that has electrically conductive inclusions dispersed to improve thermal and electrical conductivity and a passive treatment applied to the surface to provide corrosion resistance. Two carbon fiber tanks hold 3.75kg of H ₂ at 5,000psig providing a range of ~170 miles. 10,000 psig tanks would increase energy storage by about 66%. 1kg H ₂ = 39kWh. Fueling time is three minutes, about the same as a gas car. An ultra capacitor bank is used to deliver power at high rates and absorb regenerative braking power at high rates. The ultracaps don’t have the slower electrochemical reaction of a battery or the attendant heat generation. The capacitor has the simpler physics of just storing electrons. Most other fuel cell cars use batteries. Top speed is 93mph.

DaimlerChrysler. The fleet of fuel cell vehicles for Daimler consists of 100 buses, vans, and cars that are located throughout the world in all kinds of driving conditions and weather. The F cell uses compressed hydrogen at 350bar with an amount sufficient for about 100 miles. Top speed is 85mph. Sounds slow for the Autobahn, could be way too fast for L.A.

Auxiliary Power Units (APU) for Trucks, Buses, and RVs. A number of companies with deep experience in present technology APUs are teaming with various fuel cell companies to explore solid oxide fuel cells (SOFC) for this application. Reduced emissions, quiet operation and lower fuel consumption are the benefits they are looking to provide.

SOFC on Reformed Diesel for Heater APU by Webastco AG. A manufacturer of APUs for trucks and buses is developing a SOFC heater that runs on reformed diesel fuel. The 700W unit has 50 start/stop cycles, 2000 hours operating at 250ma/cm²with 57% fuel utilization. Staxera GmbH is providing the stack of planar cells. Reformer is being done by Webastco and existing pumps and blowers are used for balance of plant (BOP).

Vibration resistance of 16g in z axis and short startup times of <1 hour are among the key specifications that need to be met.

Ballard Road Map. Figure 6offers a good way to visualize the current state of Ballard’s fuel cell stack technology for automotive, providing a perspective on what has been accomplished and what is needed to reach the milestones to allow a production decision.

LP Natural Gas SOFC APU by Cummins. Cummins Power Generation is the world’s largest manufacturer of generators for the RV market. The Department of Energy’s Solid State Energy Conversion Alliance (SECA) is developing 3-10kWe SOFC in a 10-year 3-phase effort. SOFCo-EFS Holdings is developing the all-ceramic planar stack and waterless CPOX LP natural gas reformer. BOP design approach is to use automotive components for cost and reliability. Trials show power densities of 280 mW/cm², 65% fuel utilization and power degradation rates as low as 2%/500 hours of operation.

Delphi SOFC APU for Transportation and Stationary. The focus is on 3-5kW SOFC development. A cell cassette design using high-volume manufacturing processes of stamping, brazing, and laser welding has been developed with 30-cell stacks demonstrating 578mW/cm², 24% fuel utilization using simulated reformate ( 48.5% H₂, 3%H ₂ O, rest N ₂ ). Power degradation has been ~10%/2000 hours.

Fuel Cell Electricity and Heat for
Residential and Commercial Use

Distributed generation (DG) is being explored because SOFCs are an energy source with virtually no emissions versus the NO _x , SO _x , CO and hydrocarbons of conventional combustion generated heat and electricity. They offer a big advantage in their flexibility of using the fuels of today – coal gas, natural gas, propane, biogas – while being easily converted to hydrogen in the future. DOE’s SECA is promoting SOFCs and trying to cross the chasm from a niche solution to the widespread first choice of the marketplace by getting capital costs down to $400/kW for stationary and axiliary power units (APU) by 2010, making it the economic frontrunner. For comparison, a diesel generator comes in at $800-1500/kW and a natural gas turbine even less while SOFCs are in the $3,000 to $4000/kW neighborhood. SOFC technical feasibility has been demonstrated by successful operation of 100kW combined heat and power plant without any performance degradation over two years. The heart of the system is a solid oxide electrolyte which acts as a conductor of oxide ions at temperatures of 600-1000°C. Ceramic material allows oxygen to be reduced to oxide ions on the cathode. They are transported to the anode zone where they react with hydrogen giving up electrons to an external circuit. The primary goal now is reduction of capital costs. Under SECA, DoE has assembled six competing industry teams – Cummins SOFCo, Delphi-Battelle, General Electric, Siemens-Westinghouse, Acumentrics, and Fuel Cell Energy. Different cell designs and many collaborative efforts are under way. SOFC can be configured as tube or plate. The plate helps with manufacturing because a lot of existing processes and equipment can be used. Reforming can be done internally. The most common oxides used are zirconia and yttria. One strategy for cost reduction is mass customization of some common modules.

General Electric is working on two SOFC systems. An ambient pressure, simple cycle 5kW prototype SOFC running on natural gas with auto thermal reforming (ATR). Analysis indicates a 35% efficiency target can be reached. A 40-cell stack with 16-inch diameter planar cells yields 288 mW/cm²and 80% fuel utilization, using simulated ATR fuel. The second system is a pressurized hybrid SOFC with a gas turbine using the residual fuel. The SOFC produces 80% of the electricity. The objective is to develop and assess multi MW system concepts. Planar design SOFCs that are anode supported with metallic interconnects run at 800°C with a system efficiency >65%. The hybrid system can operate on coal using a gasifier. The overall efficiency of coal to AC power is at least 50%. Several important demonstrations have been realized – large planar SOFC of 40cm diameter, operating pressures of 4atm, and 80% fuel utilization.

Siemens-Westinghouse. In an attempt to reduce the ohmic resistance of conventional round tubular SOFCs that have only two current routes with long paths, an oval geometry tube design with integral ribs that provide multiple electrical current paths offering lower resistance through their shorter distances has been developed. Other benefits include reduced thickness of the air electrode wall which lowers diffusion polarization losses, and the geometry provides a volumetric power density increase. Testing showed an increase of 50% in power density going from a tube with 200ma/cm²to a 5-channel design with 300ma/cm²at 900°C, 85% fuel utilization. No performance degradation was exhibited after 1000 hours. The next step is optimizing the number of ribs.

Fuel Cell Technologies, Ltd. Since 2001, 5kW SOFCs have been run using Siemens-Westinghouse’s tubular cells in first generation field trials in a variety of applications in a number of countries for R&D purposes – small commercial combined heat and power in Japan, volatile organic compound elimination at Ford Dearborn, remote power in Alaska, a residential CHP in Germany. There was a build of 20 Generation2 units in 2005 that use low pressure natural gas (2 psig). Cost reduction is the next big challenge with $1,000-2000/kW the immediate goal. A five-year payback can be shown for SOFC over diesel generators in fuel and maintenance costs at a price of $2,000/kW.

UTC. A long-time leader and market presence in fuel cells, UTC has a wealth of experience in the DG space with its 200kW phosphoric acid fuel cell (PAFC) with up to 900K BTU/hr of heat for cogeneration applications for commercial stationary. To gauge size, consider that 200kW is enough for about 100 average households. The PAFC uses concentrated HPO ₄ as an electrolyte which is retained in a silicon carbide matrix. Pt catalysts are used for the anode and cathode. PAFCs operate at >160°C; otherwise the ionic conductivity is poor and CO poisoning of the catalyst results. It runs on natural gas using a reformer. CO ₂ is not a problem so reformed fuel can be used. Since 1991, 275 systems have been in place with 7,000,000 hours of operation in schools, office buildings, hospitals, and manufacturing. Grid-connected and operating in parallel, they can be grid independent automatically. No pollution, no emissions and a small amount of waste heat (20%) compared to conventional power plant electricity (67%) because heat can be captured for energy generation or heating and cooling and there are no transmission line losses. However, it faces the same capital cost issues as SOFCs coming in at about $3,000-4,000/kW.

Plug Power. A high temperature PEM FC design is being used for Plug Power’s residential heating 4.6 kW electricity, 9kW heat unit for multi-family dwellings. Typically PEM FCs use Nafion and operate well below the 160°C temperature used in this design that uses a PBI (polybenzimidazole polymer) PEM from PEMEAS, Germany. The high temp PEM FC solves a number of problems – the MEA is CO tolerant, it eliminates a gas treatment step in the reformer, no humidification or water management issues, and the design results in 30% fewer parts.

Acumentrics. Working to SECA’s goal of $400/kW, cost reductions are being made by increasing cell power which reduces the number of cells needed, and employing technologies like metal injection molding (MIM) for low cost intricate geometry metal parts. Telecommunications and remote residential will operate on gas and propane with diesel and JP8 for military. Investors include Sumitomo Japan, General Dynamics, Chevron Texaco, and Northeast Utilities.

Integrated co-sintered stack with metal structural support at Argonne National Lab. A way of improving the mechanical properties of durability, shock, and thermal cycling for SOFCs is proposed by co-sintering the brittle electrolyte and anode with metallic gas flow fields and bipolar plate to form an integrated unit for assembling the stack wherein the metallic units serve as the structural members. In addition, they will use ceramic to metal bonds for sealing instead of glass-ceramic.

Flexible Zirconia Electrolyte at Corning. Novel planar technology that is robust for use in 200kW+ SOFCs is based on thin, flexible zirconia electrolyte sheets that can bend to a radius of less than 1cm. This gives them high tolerance for local thermal gradients in electrolyte supported multi cell design (ESM).

Proprietary Cu Anode for SOFC. Franklin Fuel Cells has been working on SOFCs for the last two years that can operate on fuels available today — diesel, gasoline, ethanol propane, as well as, hydrogen in the 3-250kW range. A proprietary copper anode (composite of Cu, CeO ₂ , YSZ) direct oxidation SOFC provides 300mW/cm2 at 800°C on gasoline with no steam or carrier gas, no external reforming. Significant technical problems it must overcome: 1) carbon formation in the fuel distribution system from pyrolysis and 2) prevention of copper sintering which reduces conductivity and decreases anode operation. Typical fuel cells use Ni and YSZ. However, Ni catalyzes the formation of graphite deactivating the cell with carbon deposition. Cu does not.

Fuel Processors

High Sulfur Fuel Processor by Mesoscopic Devices. Fuel cells operating on readily available hydrocarbon fuels are slow to be realized, in part because of the poisoning of the fuel cell and the reformer catalyst by S compounds; the S species must be removed. A regenerable sorbent is desirable for high sulfur fuels for low maintenance, and long runtimes. Mesoscopic has shown a continuous regeneration of the sorbent is an approach that can be efficient and compact for key military fuels like JP-8 and diesel.

Methanol Reforming for Portable and Stationary by Genesis Fuel Tech. Sulfur bearing fuel reforming technology (e.g. diesel, natural gas, propane) has a large number of process steps, control points, catalytic degradation, and poisoning issues. Plus, separate purified water needed for the process must be kept from freezing. Methanol is more straightforward and the water needed can be mixed right in which also avoids freezing problems. The beauty of the Genesis system is that it is as simple as connecting the fuel cells with regulated H2. It can load track without limitations on ramp up and can handle 0-100% transient and can ramp all the way down. Yield is 20l/minute H2 output for the MeOH/water reformer with 99.9999% purity. Weight is 25kg, size 23x53cm.

U.S. Department of Energy’s Role in Commercialization

DOE Hydrogen Program. DOE is executing a balanced research portfolio for developing fossil, nuclear, and renewable based hydrogen production. Hydrogen from coal will be based on gasification not coal-based electricity. For this carbon capture and sequestration technologies are needed. The nuclear program will rely on heat-based generation of H2. In transportation, DOE has set 2015 as the date for a decision on industry commercialization of FC vehicles. Goals for H2 storage technology are 2.0kWh/kg (6%wt), 1.5kWh/liter.

DOE’s Office of Fossil Energy’s National Energy Technology Labs in Morgantown, West Virginia, and Pittsburgh, Pennsylvania. Its SOFC and fuel cell turbine (FCT) hybrid distributed generation (DG) has three aspects:

SECA, Solid State Energy Conversion Alliance is supporting the development of modular, fuel-flexible SOFCs with a cost target of $400/kW for stationary and APU by 2010.

FutureGen. The goal is for coal-generated electricity and H ₂ generation by gasification. CO ₂ will be separated from H2 by novel membranes under development with a captured rate of 90%. Ion conducting metal oxide ceramics in SOFC and ceramic membranes for H2 production are key.

High Temperature Electrochemistry Center, HiTEC, has been established at the Pacific Northwest National Lab (PNNL) with satellite facilities at Montana State University and University of Florida at Gainesville. Solid oxide technology is under study in a number of areas, e.g., electrolyzers, reversible FCs, gas separation membranes, all-ceramic fuel electrode for steam electrolysis.

Portable Fuel Cells

There are many bets on the portable device market as the place for fuel cell technology to make a commercial entrance for a number of reasons. These applications accept a much higher cost per watt-hour than other fuel cell markets, very long runtimes are highly desirable and existing battery technology doesn’t offer a good solution, attributes of small size and light weight are strong drivers in portable products, and the infrastructure for distribution of fuel is not a great problem. In addition, portable military applications echo these same needs to an even more pronounced degree and it can be a source of funds for R&D because the battlefield is transitioning and increasingly becoming more and more electronics-dependent.

Motorola. An MeOH steam reformer coupled with an elevated temperature PEMFC (>120°C) using PBI MEAs (polybenzimidazole doped with strong ox-acids) is being studied because of a list of advantages — higher power density, lower precious metal catalyst loading, low gas permeability, no humidification, simplified water management, (only gas phase water is present), and enhanced kinetics versus low temperature PEMFCs which also have the added difficulty of generating and storing pure hydrogen or DMFC. A 25W system has been demonstrated.

DMFC MTI MicroFuel Cells continues to develop its DMFC running on 100% MeOH with a passive air supply. In an implementation of the FC as a battery extender for an RFID tag reader, the device provides 1 watt of power output to charge an 8Wh Li-ion battery through an upconverter providing an additional 35Wh of extended runtime from the MeOH cartridge. Issues for further development are high precious metal loading and sensitivity to changes in ambient conditions. Dynamics of system operation for load following and slow startup make the hybrid approach necessary.

Green Fuel Cell, Tel Aviv, Israel is addressing the key limitations of cost, energy density, power density, water management and flooding with their pure methanol, nano porous proton conducting membrane, PEM FC. Their PEM cost today is $40/m2 and represents less than 1% of the cost of their 20W accessory power unit for laptop computers which run at 200mW/cm2 and provide 380Wh/l, 290 Wh/kg with a 125ml methanol cartridge. Water is recyled in situ from cathode to anode through the membrane so there is no need for water collection or pumps.

U.S. Army. The Communications-Electronics Research, Development and Engineering Center, CERDEC, at Fort Belvoir, VA has a number of programs for its portable power needs with a range of sizes from 25-250W. And as you might expect, the demands are many and extreme — light weight, rugged, compact, wide environmental ranges in temperature, humidity, high tolerance to dust and sand, rapid start, and silent operation. One project under development is a DMFC by SmartFuel Cell, Germany. One version is a neat methanol for operation at 0-35°C. The other is a dilute methanol for up to 50°C in a desert environment. They show a 400Wh/kg energy density for a 72-hour, 20W mission. Ultracell Inc. is providing a 25W reformed methanol fuel cell for the Land Warrior program. Using hydrogen generation systems of ammonia borane (NH ₃ BH ₃ ) General Atomics has a 20W PEMFC and General Dynamics has a unique metal/ceramic PEM FC. In addition, some work on SOFC is being supported. The attraction is the fuel flexibility (e.g., diesel, JP-8) which will support the “One Fuel Forward” policy of the DoD. However, this technology is much less mature and robust at this stage. Adaptive Materials Inc. and NanoDyanmics will provide evaluations of 50-150W portable SOFC using propane. NanoDynamics and Altex Technologies will demonstrate 50W JP-8 fueled SOFC. A 250W field charger that uses JP-8 for 72 hours of operation weighs less than 10kg (no fuel) is being worked on by Idatech and Genesis FuelTech.

In fuel processing, SOFCo EFS Holdings LLC will use its experience in converting heavy hydrocarbon to FC suitable fuels and S removal on converting military fuels. General Dynamics and Aspen Products Group are providing a 5kW with JP-8 reformate with a composition of 24% CO, 22% H ₂ , 51% N ₂ where S went from 400ppm to 4ppm.

STEP is the Small Tactical Electric Power program for filling the need for emerging man-portable power 500-3000W. Power sources must be light weight, rugged, compact, have a wide temperature and humidity range, be immune to dust and sand, and have rapid start with silent operation.

Portable 75W SOFC-Battery Hybrid by Mesoscopic Devices. The SOFC, typically thought of for multi-kilowatt stationary systems, is getting a lot of attention for portable applications based on achievements in higher power density and compact reformers. So portable SOFCs that may compete with PEM FC and DMFC are being proposed. Mesoscopic Devices for the past three years has been developing SOFCs under 500W. They have demonstrated a 75W generator for military use that is 130x180x250mm, weighs 3kg, runs on propane with an internal hybrid battery for start up and peak power. Half the volume is BOP with the largest parasitic power and noise source being the blower. The FC kicks in after a 45 minute start up. Operation is continuous for several days. Future versions will run on kerosene, jet fuel or JP-8 using a liquid phase desulfurizer.

Portable Hydrogen Generation with NaBH ₄ . Millennium Cell is offering a Hydrogen-on-Demand system which produces H ₂ by releasing it from NaBH ₄ in the presence of a proprietary catalyst. The remaining end product of this reaction is NaBO ₂ which must be discarded. In practice, this is much like disposing of an expended primary battery. From the business side, they are focusing on the military as early adopters with the longer-term market consumer electronics like laptop computers where a 2 -to-3 runtime is sought. As a demonstration, Millennium Cell shows a flat panel passive PEM FC using a Hydrogen-on-Demand fuel cartridge. Another exhibit has it coupled with a Protonex PEM FC for a 30W, 72-hour soldier application where it weighs in at 12 pounds versus 28 pounds for the existing LiSO ₂ batteries. Field trials for this device will take place throughout 2006.

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