Affordable hydrogen supply pathways for fuel cell vehicles

Affordable hydrogen supply pathways for fuel cell vehicles

ht. J. Hydrogen Energ.v, Vol. 23, No. 6. pp. 507 -516, 1998 (‘I 1998 lnternatiorlal Associntion for Hydrogen Energy Elsevier Science Ltd Pergamon Al...

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ht. J. Hydrogen Energ.v, Vol. 23, No. 6. pp. 507 -516, 1998 (‘I 1998 lnternatiorlal Associntion for Hydrogen Energy Elsevier Science Ltd

Pergamon

All rights reserved.Printed in Great Britain

PII: SO360-3199(97)00102-X

AFFORDABLE

036OG3199/98

HYDROGEN SUPPLY PATHWAYS CELL VEHICLES

$19.00+0.00

FOR FUEL

C. E. THOMAS,* 1. F. KUHN, JR, B. D. JAMES, F. D. LOMAX, JR and G. N. BAUM Directed Technologies, Inc., 4001 North Fairfax Drive, Suite 775, Arlington, Virginia 22203, U.S.A.

Abstract-Fuel cell vehicles can be powered directly by hydrogen stored on the vehicle, or indirectly by extracting hydrogen from onboard liquid fuels such as methanol or gasoline. The direct hydrogen fuel cell vehicle is preferred, since it would be less complex, have better fuel economy, lower greenhouse gas emissions, grcatcr oil import reductions and would lead to a sustainable transportation system once renewable energy was used to produce hydrogen. The two oft-cited concerns with direct hydrogen fuel cell vehicles are onboard hydrogen storage and the lack of hydrogen supply options. Directed Technologies, Inc., working with the Ford Motor Company under a Department of Energy

cost aharrd contract to develop direct hydrogen fuel cell vehicles, has addrcsscd both perceived roadblocks to direct hydrogen fuel cell vehicles. We describe realistic, cost effective options for both onboard hydrogen storage and for economically viable hydrogen infrastructure development. s[c 1998 International Association for Hydrogen Energy

that have previously been perceived as potentially insurmountable: compact, light weight onboard hydrogen storage and construction of a national hydrogen pipeline or tanker truck network that could cost tens of billions of dollars and take many years to install. Faced with these two barriers, the U.S. Department of Energy has decided to place primary emphasis on developing the conventional liquid fuel option initially, even though this option would reduce the environmental and oil displacement benefits of the direct hydrogen fuel cell vehicle. The Partnership for a New Generation of Vehicles (PNGV) has also adopted the liquid fuel option for fuel cell vehicles to meet its proposed 1997 date for downselecting vehicle technology to meet its 80 mpg fuel economy goal by the year 2004. This report describes a conceptual fuel cell vehicle design and a hydrogen infrastructure development scenario that would essentially eliminate both barriers to direct hydrogen fuel cell vehicles. The hydrogen infrastructure barrier may appear to be the most daunting, since any fueling infrastructure must meet two goals: the

INTRODUCTION Recent advances in proton exchange membrane (PEM) fuel cell performance have stimulated increased interest in private

passenger

fuel cell vehicles.

Ballard

Power

Sys-

tems of British Columbia has published achieved specific power levels of 0.7 kW/kg for the fuel cell stack, approaching the U.S Department of Energy (DOE) goal of I kW/kg, and they have reached the DOE power density goal of 1 kW/liter. Platinum catalyst loadings have been demonstrated below 0.2 mg/cm’ by Los Alamos National Laboratory and others, which translates into approximately $175 per passenger car, or two orders of magnitude less than projected platinum costs a decade ago. A detailed analysis of potential fuel cell stack costs shows that the DOE goal of $35/kW is achievable in large scale mass production [ 11. Despite these advances in basic fuel cell technology, the fueling options for fuel cell vehicles are uncertain. The nascent fuel cell vehicle industry faces a fundamental choice: a complex vehicle design and moderate (methanol) or no (gasoline) infrastructure impact, or a simplified

and

less costly

vehicle

design

coupled

with

hydrogen

requirement for a new hydrogen fueling infrastructure. The direct hydrogen FCV approach reduces vehicle complexity and eliminates the need to develop reliable onboard chemical processors, but faces two other hurdles

companies *Author

to whom

all correspondence

should

must

be affordable,

preferably

no more

costly

than gasoline per mile driven, and the hydrogen infrastructure investment options must be flexible and incremental. If the only low cost hydrogen option is to build enormous hydrogen production plants costing tens of millions of dollars, then the vehicle/infrastructure chicken and egg dilemma will be exacerbated: automobile

the

will

be reluctant

to build

fuel cell vehicles

until

the hydrogen infrastructure is in place, and hydrogen gas companies will not make the investments in large

be addressed. 507

C. E. THOMAS

508

production plants until hundreds of thousands of fuel cell vehicles are on the road. This report describes an affordable and flexible alternative to building large hydrogen production facilities. But first, we describe a direct hydrogen fuel cell vehicle design that would meet the range, acceleration, passenger space and fuel economy goals of the PNGV. DIRECT

HYDROGEN RANGE AND

FUEL CELL VEHICLE FUEL ECONOMY

A vehicle design team at the Ford Motor Company has designed a “ground-up” concept car that could incorporate either 5000 psig compressed hydrogen or liquid hydrogen tanks. This conceptual vehicle is similar to a midsize, five-passenger Ford Taurus. The compressed hydrogen version includes 3.58 kg of onboard hydrogen in three 5000 psig fuel tanks-two short cylindrical tanks in the space normally occupied by the gasoline tank, and one long tank placed in the tunnel that previously would have housed the drive shaft of a rear wheel drive vehicle. There is no intrusion into the vehicle trunk space. These fuel cell vehicles have been designed to have the full range, acceleration and passenger space of comparable gasolinepowered vehicles. Directed Technologies, Inc. (DTI) has

et al.

previously shown that these compressed hydrogen tanks could be cost competitive in large scale production runs

PI.

We have analyzed the range and fuel economy of three classes of vehicle gliders based on this ground-up fuel cell vehicle design. First we assumed that the vehicle glider has the weight, aerodynamic drag and rolling resistance characteristics of the aluminum intensive vehicle (AIV) version of the Ford Sable. As shown by the first bar in Fig. 1, this fuel cell vehicle would have a range of about 290 miles on the EPA combined driving schedule (55% urban and 45% highway). The second bar illustrates that this fuel cell vehicle would meet the 380-mile range goal of the PNGV, provided that the vehicle weight and drag characteristics also meet the PNGV goals. The last bar of Fig. 1 shows that this fuel cell vehicle could travel about 440 miles on the EPA combined driving schedules on one tank of hydrogen, if the drag coefficient was reduced to 0.2, similar to the Ford Synergy 2010 or the GM Impact. The lower mark on all three bars indicates the likely range on the more realistic accelerated EPA driving cycles, where the speed at each time period is multiplied by 1.25 to more closely reflect actual driving habits. The corresponding fuel economies for these three fuel

Driving Schedules: q Combined

(55%/45%)

400 Vehicle

Glider

Characteristics:

AIV-Sable I PNGV I Future 1,344 I 1,032 I 1,032 kg 0.33 IO.27 IO.20 2.13 12.08 12.00 m2 Ree: 0.0092 IO.0072 IO.0072

Test Wgt: Drag: Area Rolling

250

Ford AIV Sable FCV

PNGV FCV

Future FCV Max Regen Braking Eff = .96"2x.91"2w.60=

.92x.9459x

0.50

Common Parameters: Drivetrain Eff: 96% Transmission Peak ER: 94.5% Battefy 2-way Eff: 80% Peak Motor Eff: 91% FC Eff Q 5 kW: 61.2% FC Eff Q Peak Power: 44.5% 7% Hill Climb: 55 mph Sustainable speed: 85 mph Sustainable 3% Grade: 65 mph Accessory Power: 500 W

Fig. I. Fuel Cell Vehicle (FCV) range on 3.58 kg of hydrogen assuming (a) current vehicle characteristics of the Ford AIV Sable, (b) vehicle parameter goals for the Partnership for a New Generation of Vehicles (PNGV), and (c) range for a vehicle with very low drag coefficient (0.2).

HYDROGEN

SUPPLY

cell vehicle types are shown in Fig. 2. Even with the existing AIV Sable body parameters, this direct hydrogen fuel cell vehicle would achieve the PNGV goal of 80 mpg on the combined EPA driving schedules. With the PNGV body parameters, the fuel economy would be over 100 mpg, and this FCV would exceed 80 mpg even on the more realistic 1.25 times accelerated combined driving cycles. With the 0.2 drag coefficient, this FCV would reach over 100 mpg fuel economy on the accelerated 1.25 driving schedules, and over 120 mpg on the EPA combined cycles. We conclude that direct hydrogen fuel cell vehicles with suitably compact, light weight 5000 psig or liquid hydrogen tanks with 3.58 kg capacity could simultaneously meet the PNGV performance goals and also the California zero emission vehicle target. But hydrogen must be available when and where it is needed to support these fuel cell vehicles, which is the subject of the rest of this paper. HYDROGEN CONVENTIONAL

PRODUCTION BY INDUSTRY PRACTICE

The Ford Motor Company funded a major analysis of hydrogen fueling options under a cost-shared contract

509

PATHWAYS

with the U.S. Department of Energy on direct hydrogen fuel cell vehicles. Directed Technologies, Inc. coordinated this investigation, which included subcontracts to Air Products and Chemicals, BOC Gases, The Electrolyser Corporation, Ltd., and Praxair. These companies designed and costed four different methods for producing hydrogen: steam methane reforming, electrolysis of water, steam reforming of methanol and partial oxidation of heavy oil. The primary emphasis, however, was on steam methane reforming, the most common industrial method for generating hydrogen today. The subcontractors evaluated four different hydrogen transportation options: a large liquid hydrogen plant sited near sources of low cost natural gas with cryogenic tanker truck delivery, a regional liquid hydrogen plant with truck delivery, a regional gaseous hydrogen plant with pipeline delivery, and various sizes of steam methane reformers located at the hydrogen dispensing site. Most hydrogen for commercial sale today is made at large scale steam methane reformer plants, liquified, and shipped by cryogenic tanker truck to the customer. To fill compressed hydrogen tanks on fuel cell vehicles, the liquid hydrogen would be vaporized and dispensed into the tanks at high pressure. Figure 3 summarizes the expected cost of hydrogen (in $/kg) produced in such

Driving Schedules:

Vehicle

Glider Characteristics:

AN-Sable / PNGV I Future Test Wgt:l344 I 1,032 I 1,032 kg Drag: 0.33 IO.27 IO.20 Area: 2.13 t2.08 12.00 m2 Rolling Res: 0.0092 / 0.0072 IO.0072

Ford AIV Sable FCV

Fig. 2. Fuel economy

PNGV FCV

for the same set of

Future FCV

Common Parameters: Drivetrain Etk 96% Transmission Peak Eff: 94.5% Battery away Etfz 80% Peak Motor Eff: 91% FC Eff r?Q 5 kW: 61.2% FC Eff 6 Peak Power: 44.5% 7% Hill Climb: 55 mph Sustainable speed: 85 mph Sustainable 3% Grade: 65 mph Accessory Power: 500 W

three fuel cell vehicles as Figure

1,

C. E. THOMAS

510

et ul.

0 Operation & Main. 2.5

Natural Gas = $1.89/GJ; Electricity =5 cents/kWh: Utilization Factor = 0.607; Capital Recovery Factor = 18.42% t/d = metric tonnes/day

Praxair 21.5tld 40900

AirProd. 26.3 t/d 50100

BOG 43.9 tld 83300

Praxair 215.41/d 409000

AirProd. 263.5tId 500400

e

No. of FCVs Supported

Fig. 3. Delivered cost of gaseous hydrogen from large, remote liquid hydrogen production plants, including cost of production, liquefaction, delivery and dispensing at 34.5 MPa.

large scale steam methane reformer plants located near sources of inexpensive ($1.90/GJ) natural gas. The plants are listed in order of increasing size, with the size specified both in average hydrogen output (metric tonnes/day) and also in terms of the number of fuel cell vehicles supported (divide these numbers by eight to determine the number of vehicles actually refueled each day). All estimates include the cost of hydrogen production, transportation, compression, storage and dispensing into 5000 psi compressed tanks onboard the fuel cell vehicles. Financial assumptions include a 10% real, after-tax return on investment, which translates into an 18.4% annual capital recovery factor. As shown in Fig. 3, hydrogen could be delivered at a cost of about $3/kg, which would be comparable to gasoline selling at $l.l2/gallon. That is, fuel for a gasolinepowered Ford AIV Sable supplied with $l.l2/gallon gasoline would cost as much per mile as a hydrogen fuel cell AIV Sable fueled with $3/kg hydrogen. This cost equivalence is based on computer driving cycle simulations which demonstrate that the fuel cell vehicle with regenerative braking would have about 2.7 times greater onboard fuel economy (on a lower heating value basis) than a gasoline vehicle with the same body characteristics

operating on the 1.25 times accelerated combined (55% urban/45% highway) driving schedules. On the more gentle EPA Federal Urban Driving Schedule (FUDS), the fuel cell vehicle would fare even better: 3.4 times greater fuel economy than the gasoline vehicle. For details on these cost estimates, see Ferrell [3], Halvorson [4] and Moore [5]. Over half the cost of hydrogen from these one-of-akind large plants is due to liquefaction (both capital and electricity to run the liquefier) and transportation. These costs could be eliminated if smaller steam methane reformers were constructed at the hydrogen fueling station. The natural gas pipeline network then becomes the primary energy delivery infrastructure. Figure 4 shows the hydrogen cost estimates for one-of-a-kind steam methane reformer systems built on-site, shown in order of decreasing size. In general, the hydrogen costs increase with reduced plant size, as expected. The Praxair 2.72 tonne/day design shows that hydrogen could be produced and delivered to a 5000 psi tank for $2.27/kg, well below the target cost of hydrogen at $3.21/kg (equivalent to fully taxed gasoline at $1.20/gallon), and approaching $2.14/kg which is equivalent to wholesale gasoline at $0.80/gallon.

HYDROGEN

SUPPLY

PATHWAYS

511

-10 g9 =8

8

07

0 AirProducts 2.72 Ud 5,400 FCNS

Pwair 2.72 t/d 5,400 FCUS

Bee 1.36Ud 2,700 FCVS

Pmair 0.45 ud 900 FCVs

Boc

0.18 tm 360 FcVs

Dll:l0lNRw;T*BREB(o-

Fig. 4. Delivered

cost of hydrogen

from

on-site

steam methane

But even this Praxair on-site plant would produce enough hydrogen to support about 5,400 fuel cell vehicles. It will be many years before 5,400 vehicles would be within range of a single refueling station. Furthermore, the cost of such a one-of-a-kind plant ($5.5 million) would be difficult to justify without the requisite number of vehicle users. Smaller hydrogen fueling options are therefore needed in the early days of fuel cell vehicle market penetration. But the cost of hydrogen increases significantly for a smaller one-of-a-kind unit built on site, as shown by the two bars on the right side of Fig. 4, rising to $1 l/kg or three times the price of gasoline for the BOC plant supporting 360 fuel cell vehicles. FACTORY-BUILT

HYDROGEN APPLIANCES

FUELING

As an alternative to on-site construction, we considered two fueling options for the early transition strategy for fuel cell vehicles: small scale, factory-built steam methane reformers and factory-built electrolyzers. Rather than achieving economies of scale by building large hydrogen production plants at a central location, this paradigm achieves low cost through the economies of mass production in a factory. The hydrogen fueling

reformers

constructed

on-site

at the refueling

11*11911

station.

appliances are manufactured in a central factory and shipped around the country, much like home furnaces or other home appliances. Fortunately we already have one example of such a factory-built steam methane reformer. International Fuel Cells (IFC) manufactures their PC-25 200-kW phosphoric acid stationary fuel cell system in South Windsor, Connecticut. The front end of this system includes a steam methane reformer to produce a hydrogen-rich gas stream from natural gas. The PC-25 is shipped around the world, installed by the customer and operates unattended. IFC does not even send an engineer to supervise installation and start-up. DTI has estimated the costs for a factory-built steam methane reformer for the transportation market based on the IFC technology. A pressure swing adsorption system, compressor, storage system and dispenser were added. The resulting hydrogen cost estimate for this factory-built system is compared with the units built onsite in Fig. 5. The 0.18 tonne/day factory-built system is projected to produce four times less costly hydrogen than the equivalent size BOC one-of-a-kind plant constructed on-site, half the cost from the larger 0.45 tonne/day Praxair unit, and only slightly more costly hydrogen than that from the 2.7 tonne/day plant, even though the factory-

C. E. THOMAS

512

et al.

1 11 10

/Natural Gas Costs $3.79/GJ Electricity Costs 6 centskWh Price includes Dispensing at 5,000 psi Capital Recovery Factor = 16.42% : Plant Capacity Factor = 69% Small, FactoryBuilt Appliance

AirProducts 2.72 t/d 5,400 FCVs

Praxair

2.72 t/d 5,400 FCVs

BOC

1.36 t/d 2,700 FCVs

Praxair

0.45 t/d 900 FCVs

BOC 0.18 t/d 360 FCVs

DTI I IFC 0.18 t/d 360 FCVs

Fig. 5. Delivered cost of hydrogen from on-site from a factory-built steam methane reformer system based on the International Fuel Cells (IFC) PC-25 stationary fuel cell system reformer.

built unit produces 15 times less hydrogen. Ogden [6] and her colleagues at Princeton have shown similar cost savings from small scale reformers designed for fuel cell systems compared to reformers constructed on-site. They attribute part of the increased cost of the industrial steam reformers to the higher temperatures and pressures than the PC-25 type reformer. The factory-built cost estimate in Fig. 5 assumes low production volume manufacturing methods. With higher volume production, DTI projects the potential for further cost reductions for the fueling appliance, as indicated in Fig. 6 for production of 100, 1000, and 10,000 refueling systems. We have also assigned cost scaling factors to extrapolate the cost of the PC-25 based technology to even smaller units. In this case, the delivered cost of hydrogen could be less than the equivalent cost of wholesale gasoline for hydrogen appliances as small as those supporting 50 fuel cell vehicles. This is in the range of early fleet vehicle demonstration projects. Another alternative would be to utilize the electrical power grid to “deliver” hydrogen instead of (or in addition to) the natural gas pipeline system. Electrolyzer systems could be installed in very small sizes, including home electrolyzers to supply hydrogen to just one or two

vehicles. The Electrolyser Corporation is in fact developing such a device, coupling an alkaline electrolyzer to a compressor to fill the vehicle tanks over night (See Fairlie [7]). In addition, a new company, Proton Energy Systems, has been formed specifically to produce PEM electrolyzers for hydrogen production. Again, these would be factory-built appliances with the potential for cost reductions with mass production. The costs of electrolytic hydrogen are compared with the costs from trucked-in liquid hydrogen (including vaporizers and dispensers to fast-fill 5000 psig vehicle tanks) and various steam methane reformers in Fig. 7. The electrolytic hydrogen costs (dashed curves to the left of Fig. 7) were developed in cooperation with The Electrolyser Corporation and Ford Motor Company. The cost of electrolyzers in large volume mass production was estimated though a detailed process of analysis, breaking each component into its constituent parts, and scrutinizing each part to determine the lowest cost production technique. We then calculated the manufacturing progress ratios that would be necessary to produce the estimated mass production cost starting from today’s low production volume cost. These calculated progress ratios can then be used to estimate the component cost at

HYDROGEN

513

SUPPLY PKTHWAYS

+

Production

Quantity

= 1

- - -X - - BOC On-Site - - +

- - Praxair

On-Site

Air Products

On-Site

-Gasoline

($1.20/gal)

-Gasoline

($0.80/gal)

Nakml Gas = $3.79/61 Electricity = 6 cents/kWh Utilization = 0.69 Capital Recovery Factor = 16.4%

100 Number

1,000

of Fuel Cell Vehicles

Plant Production (kglday) = 0.56 x No. of FCv’s Supported (eg, 10,000 FCV = 5,600 kg/day)

Supported

Fig. 6. Hydrogen cost estimates for mass produced, factory-built steam methane reformers as a function of reformer output.

intermediate production rates, such as those shown in Fig. 7. Figure 7 demonstrates that electrolytic hydrogen could be cost-competitive with gasoline for units as small as lovehicle appliances, assuming 10,000 units were manufactured. Figure 7 assumes that off-peak electricity is available at 3 cents/kWh. However, with utility deregulation, Fairlie [7] reports that at least one Minnesota power marketer has quoted an off-peak electricity rate of 1.5 cents/kWh in the Chicago area beginning in early 1997. In that case. the cost of hydrogen would be competitive with fully taxed gasoline for units supporting just two or three fuel cell vehicles, and larger units could match the cost of wholesale gasoline in mass production for IO-car hydrogen appliances, as shown in Fig. 8. HYDROGEN

FUELING SYSTEM PER VEHICLE

CAPITAL

COST

The cost of hydrogen in all previous figures included charges to recover the cost of the fueling system capital investment over several years. Most fleet managers, the

likely early users of fuel cell vehicles, would be comfortable with amortizing the cost of fueling equipment over time in this manner. But others might be interested in the capital cost per vehicle. For example, home electrolyzers might be sold with the vehicle, offering the driver the option of home refueling with the capital cost covered by car payments instead of buried in the fuel costs. In addition, the cost per vehicle for the hydrogen fueling system should be compared with the cost of onboard fuel processors, which would in fact have to be included in vehicle purchase price, and with the cost of gasoline infrastructure annual maintenance and replacement. The required investment cost for hydrogen appliances per fuel cell vehicle is summarized in Fig. 9. According to our projections, hydrogen refueling appliances could be produced at costs less than $500 per vehicle for electrolyzer systems, or as low as $150 per vehicle for the factory-built steam methane reformer in 10,000 quantity production units. For frame of reference, Mark [8] estimates that the oil industry invests approximately $11 billion each year in new and replacement capital equipment to maintain the gasoline infrastructure. This

C. E. THOMAS

514

et cti.

-4--

[Trucked-h

4

LHZJI

C

I at 0

q

of Fuel Cell Vehicles

Electrolyzer

(ml

Electrol~er

(1,au

qiy) qty)

- -A - Electrol~er (10,wO qty) -x-sot LH2 -XPrarair LH2 [email protected] SMR (1 qty) +DTtWCSMR (100 qty) -DMFC SMR (l,COO qty) -0TVlFC SMR (10,003 qty) -0asoline (.$1.2olgal) ~Gasoline (So.SWgal) +Air Products OnSite SMR

r Elet

Number

-

Air PmJUcts LH2 Plant SCC On-Site SMR SC% LH2 Plant Pramir OmStte SMR Pmxair LH2 Plant

Supported

Fig. 7. Hydrogen costs for various hydrogen production methods, including hydrogen produced by electrolysis with off-peak electricity at 3 cents/kWh.

amounts to about $1,220 for each new car sold in the U.S., shown as the solid horizontal line in Fig. 9. This comparison illustrates that the infrastructure costs to install factory-built hydrogen fueling appliances could be equivalent to or even less than the costs incurred today to maintain the nation’s gasoline infrastructure. In effect society would be shifting new capital investments from the gasoline infrastructure to the new hydrogen infrastructure as fuel cell vehicles began to replace gasolinepowered internal combustion engine vehicles. The hydrogen infrastructure investments should also be less than the costs of installing an individual fuel processor onboard every vehicle. The U.S. DOE and PNGV have set a rather ambitious goal of $lO/kW for the onboard processor in large scale mass production, or $500 per vehicle for a 50 kW fuel cell system. However, we have assumed much higher costs for fuel processing in the Ford study. For example, even in one million production quantities, we estimate that the stationary fuel processor (steam methane reformer plus gas cleanupperforming the same functions as the proposed onboard

processors) would cost about SlSOjkW, or 18 times more than the PNGV goal for onboard processors. In other words, the cost estimates reported here are much more conservative than the onboard processing cost goals set for PNGV. Conversely, if the PNGV goals for onboard fuel processors are met, then the costs of stationary fuel processing should be much lower than reported here. The automobile industry choice of onboard chemical processing versus direct hydrogen storage is actually a choice of where fuel would be processed. Either liquid fuels are processed onboard the vehicle, or natural gas (or electricity) is processed at a stationary site to produce hydrogen. Stationary fuel processing has clear advantages with respect to warmup time, dynamic range, response time, weight, vibration, shock and temperature extremes. In addition, reforming natural gas is less complex than processing gasoline, and results in lower greenhouse gas emissions. From an economic viewpoint, the stationary fuel processor is utilized at least 12 hours if not 24 hours a day at full power, whereas the onboard chemical processor is utilized an average of one hour

HYDROGEN

SUPPLY PATHWAYS

515

-

Elecbolym

(l.ooO

Eteclmlyt.3r

(lO.ca

DlVlFC

I

I

0

SQC

m

P?axalrQn-Site Prank

Number

of Fuel

Cell Vehicles

per day, and then only at part power most of the time. Averaged over the EPA driving schedule, the effective full power utilization of the onboard chemical processor is only nine minutes per day, or an effective capacity factor of only 0.6%, or 100 times lower than the capacity factor for a stationary fuel processor. CONCLUSIONS We conclude that the two potential barriers to a viable direct hydrogen fuel cell vehicle market-onboard hydrogen storage and the hydrogen infrastructure-could be overcome. A full performance, fuel cell passenger vehicle storing either liquid or 5000 psig compressed hydrogen could be built to meet the range, acceleration, fuel economy and passenger space goals of the PNGV. Affordable hydrogen to run these fuel cell vehicles could be provided with factory-built electrolyzers and small scale steam methane reformers. These hydrogen fueling appliances could be added incrementally to match the growth of fuel cell vehicle sales, offering industry the flexibility to match supply and demand without incurring extraordinary capital investment costs for large scale

SMR

LH2

LH2

qty) qly)

(1 qly)

Plant SMR P!md

Supported

hydrogen production tkilities. The investment costs per vehicle for these stationary hydrogen fueling appliances would most likely be less than the per vehicle costs of either annual gasoline new and replacement infrastructure investments or onboard liquid fuel processors. The hydrogen produced by these small scale appliances would be cost competitive with gasoline per mile driven, and the direct hydrogen fuel cell vehicle would provide greater environmental benefits and, depending on liquid hydrocarbon choice, greater energy security benefits than the onboard processing option. Ackno,r,i~,dgements~We gratefully acknowledge the support of the Ford Motor Company and the U.S. Department of Energy under Prime Contract No. DE-AC02-94CE50389. We thank in particular Brad Bates, Al Kinnelly, Bob Mooradian, Ron Sims, Mark Sulek, Djong-Gie Oei, Georgianna Purnell and Dave Wernette with the Ford Motor Company; Steve Chalk, Donna Lee, JoAnn Milliken, Pandit Patil, and Walt Podolski of DOE; Venki Raman and Bob Moore of Air Products and Chemicals; John Ferrell and Anne Kotar of BOC Gases, Andy Stuart and Matthew Fairlie of Electroiyser Corporation; Al Meyer and Paul Farris of International Fuel Cells; and Tom Halvorson of Praxair for their many contributions to this analysis./ack

516

C. E. THOMAS

/ Factory-

et al.

FB = FactoryBuilt SMR = Steam Methane

Built h Factory-Built

Reformer

Plant Pmduction (b/day) = 0.5 x No of FCVs Supported (eg. 10,030 FCVs = 5,000 kg/day)

Steam Methane Reformers

E\

+FBSMR-Qtyl +FBSMR-CItylOO +FBSMR-Qtyl,OOO +

FB SMR - Qty 10,OOC

--*-

Electrol.

- Qty 100

-a-

Electrol.

- Qty 1,000

I

Number

Fig. 9. Hydrogen

fueling

I

I

I

10

100

1,000

of Fuel Cell Vehicles

capital

Supported

by Appliance

costs per fuel cell vehicle supported

REFERENCES 1. Lomax, Jr., F. D., James, B. D. and Mooradian, R. P., PEM Fuel Cell Cost Minimization Using ‘Design for Manufacture and Assembly’ Techniques, Proceedings of the 8th Annual U. S. Hydrogen Meeting, Alexandria, Virginia, March 1997. 2. James, B. D., Baum, G. N., Lomax, Jr., F. D., Thomas C. E. and Kuhn, Jr., I. F., Comparison of Onboard Hydrogen Storage for Fuel Cell Vehicles. Directed Technologies, Inc., Arlington, Virginia, May 1996. 3. Ferrell, J., Kotar, A. and Stern, S., Direct-Hydrogen-Fueled Proton-Exchange-Membrane Fuel Cell System for Transportation Applications: Final Report, BOC Gases, Murray Hill, New Jersey, September 1996. 4. Halvorson, T. G., Terbot, C. E. and Wisz, M. W., Hydrogen Production and Fueling System Infrastructure for PEM Fuel

for factory-built

Cell-Powered . __

wanda,

New

hydrogen

Vehicles: _. . York,

April

fueling

Final Report, . ^^ ,

appliances.

Praxair,

Inc., Tona-

IYY6.

5. Moore, R. B., Ford Hydrogen Infrastructure Study: Summary Report, Subcontract No. 47-2-R31155, Air Products and Chemicals, Inc., Allentown, Pennsylvania, March 1996. 6. Ogden, J. M.,Kreutz, T. G., Steinbugler, M., Cox, A. B. and White, J. W., Hydrogen Energy Systems Studies. Proceedings of the 1996 U.S. DOE Hydrogen Program Review, Volume I, May 1-2. 1996, Miami, Florida, p. 125. 7. Fairlie, M., FCV Fuel Supply Infrastructure: The Electrolysis Option. The Electrolyser Corporation, Ltd., Toronto, Canada, December 1996. 8. Mark, J., Fuel Choices for Fuel Cell Vehicles: Environment vs. Infrastructure, World Car Conference, Riverside, California, January 1997.