Hydrogen Technology for Vehicles: Potential and Challenges

Univ. of Maryland Energy Research Center

College Park, MD

Hydrogen Technology for Vehicles:

Potential and ChallengesMarch 25, 2011

Greg Jackson

Dept. of Mechanical Engineering

University of Maryland, College Park, MD, USA

Virginia Clean Cities Fleet Innovation: Driver

Feedback, Electric, and Hydrogen


College Park, MD

Acknowledgements

• Thanks to the following for providing slide material

– Peter Sunderland from Univ. of Maryland

– Catherine Grégoire Padró from Los Alamos National Laboratory

– Sunita Satyapal from DOE Hydrogen and Fuel Cell Program

– Pat Hearn from Ballard Power Systems

– John Turner from National Renewable Energy Laboratory

– Santosh Limaye – now with Vesta Ceramics, LLC

– Robert Kee from Colorado School of Mines


College Park, MD

1 Exajoule = 2.77*1011 kWh

Potential for

distributed power

with combined

cooling and heating

with SOFC’s and

PEMFC’s

Potential for H2 derived

from non-petroleum

sources for PEMFC

powered vehicles

from Lawrence Livermore Natl. Laboratory

http://eed.llnl.gov/flow (June 2004)

Potential for central

power SOFC’s with

carbon capture

Where we are today: Identifying the Opportunities


College Park, MD

Suggested Global Warming Abatement Strategies

for Transportation Power Needs• Reducing the dependence of transportation on oil

– Make fuels from CO2 captured from the environment

– Making fuels from biomass (preferably not food sources)

• Adaptation of fuel cell and H2-powered vehicles

– Challenge of cost and resources

• Pt loading of catalysts

– Challenge of changing fuel infrastructure for H2 delivery and storage

• Implementation of electric vehicles

– Limitations of batteries, the consumers, and the automotive market

– Environmental questions

• Improving efficiency of conventional vehicles

– Hybrid electric vehicle technology

– Increased use of diesel engines

• How far does this take us in addressing the problem


College Park, MD

Why and Why not Hydrogen for Transportation?• Hydrogen like electricity is an energy carrier not an energy supply

– Unlike electricity, it can be stored though not easily.

• Energy densities are too low and storage requires high pressures or low

temperatures.

• Fuel Cells: a historical driver for H2

– Low temperature fuel cells have needed pure H2 (<100 ppm CO) for higher power

density (approach 1 kW/liter of fuel cell, longer life (> 5000 hrs.)

• Proton Exchange Membrane (PEM) fuel cells for transportation will dictate the

needs for H2 infrastructure (leaders – Ballard, GM, Honda, UTC)

• Hydrogen is clean and can be produced from several sources

– Fossil fuels with easier CO2 sequestration

– Solar power with electrolysis or high-temperature thermolysis

– Nuclear power, wind power, and hydroelectric with high temperature electrolysis

• Competitors – synfuels, biofuels, and battery-powered vehicles

• Current Usages of Hydrogen > 50 million tons/yr & growing

– As a fuel refining agent

– Ammonia production


College Park, MD

Fueling Our Transportation Sector toward

Sustainability: Why not H2 Fuel Cells?

from Sandy Thomas using Argonne National Laboratory GREET 1.8a

-

0.5

1.0

1.5

2.0

2.5

3.0

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

Greenhouse Gas Pollution (Light duty vehicles only)

(Billion/ tonnes CO2-equivalent/year)

1990 LDV GHG

Level

GHG Goal: 60% below

1990 Pollution

GHG Goal: 80% below 1990

Pollution

FCV Scenario

Ethanol PHEV

Scenario

Gasoline PHEV

Scenario

PHEVs

Base Case:

Gasoline HEV

Scenario

100% Gasoline

ICEVs


College Park, MD

Fuel Cells and H2 in Transportation News

• DOE (Sec’y Chu) has proposed cuts

in EERE Fuel Cell program from

$179 M in FY10 to $100M in FY12

– Strongly questioned by car manufacturers

• California continuing with Fuel Cell

Partnership program

– 26 H2 fueling stations in CA

– Goal is commercial vehicles in 2017

• Japan Hydrogen Highway for fuel

cell vehicles with stations in 11

cities. METI in Japan still moving

toward commercialization in 2015 of

fuel cell vehicles.

– H2 stations run on reformed natural gas

• Many successful fuel cell bus demo

programs outside of U.S.

ISE Ultra-E™ 500 Bus

35kW battery pack

75 or 150 kW Ballard HD6

Siemens ELFA™ Motors

Honda FCX

Clarity

GM Equinox


College Park, MD

Fuel Cells and H2 in Auxiliary Power News

• DOE has identified early markets for fuel cells which

are either commercially viable or almost so

– Hybrid forklifts for warehouse applications in combination with

local H2 generation

– Back-up power for cell phones and other applications

– Stationary power for critical supplies

• Military fuel cell applications have led to many recent

increases in DOD fuel cell applied R&D

– Underwater unmanned vehicles (UUVs)

– Portable gensets operating on portable fuels

• Other applications may also be viable and fundable

through other means

– CHP or CCHP for both residential and commercial applications

– Building power in regions with high electric costs (> 10¢/kWh)

Hybrid PEM Fuel Cell /

Battery Fork Lift

http://www.ballard.com/be_informed/about_ballard/news/2007/10/09/Exide Release


College Park, MD

A DOE H2 Program Perspective on Alternative

Vehicles (Satyapal 2011)


College Park, MD

Components of Fuel Cell Vehicles

• Fuel cell vehicles

are electric vehicles

but with the

potential for much

further range than

battery-powered

vehicles.

• 430 mi range on 156

liter H2 storage tank

at 70 MPa (Toyota in

California 2009)

• 53-59% efficient

based on H2 for

typical drive cycle

(DOE EERE)


College Park, MD

Proton Exchange Membrane Fuel Cell Architecture

• Acidic polymer electrolytes

(25-100 µm thick) conduct

H+ (or H3O+) ions from

anode to cathode

– Nafion electrolytes require

hydration and thus low-

temperature operation.

• Carbon paper provide

porous media for gas

transport to active catalyst

layer for electrochemistry

• Precious metal catalyst for

H2 oxidation at anode and

O2 reduction to H2O at

cathode Image from

http://www.ballard.com/About_Ballard/Resources/How_Fuel_Cells_Work.htm


College Park, MD

Comparison of Fuel Cell Stack Technology

• Proton Exchange Membrane Fuel Cells

– Operation at low temperatures < 120ºC

– Expensive precious metal catalysts

– Fuel limited to relatively pure H2 with inert

diluents for high power density applications

– H2O management critical for most designs

• PEMFC applications – vehicles,

forklifts, small gensets, portable power

Delphi, 3.4 kW SOFC system efficiency ≈ 38%

operating on nat. gas (FC Sem. 2007)

• Solid Oxide Fuel Cells

– Operation at high temperatures > 600ºC

– Energy intensive fabrication processes

– Potential for direct fueling – coal gas, NG,

ethanol, biogas

– Readily integrated with gas turbines for

high efficiency hybrid plants

• SOFC applications – small central

power, distributed power, APU’s

Ballard Power System stack (liquid cooled

producing ~ 8 kW at ≈ 55% stack efficiency)


College Park, MD

Eo, Nernst

Crossovers and shorts Eo, experiment

Total Cell Resistances

Membrane ionicContact

resistances

Cables

Cathode Overpotential

Anode Overpotential

Mass Transport

Diffusivity under landings

(2D/3D)

Diffusivity through GDL (1D)

Catalyst Diffusivity

O2 depletion at outlet

Current Density (A/cm2)

Cell

Voltage (V)

Understanding Voltage (Polarization) Losses

in PEM Fuel Cells

Fast Transient Polarization

• Voltage losses results in heat released in fuel cell which can be used to heat

reactants, provide hot water, or other heating application.

from Pat Hearn, Ballard Power Systems


College Park, MD

PEMFCs in the News• Plug Power developed Gensys system for small-scale CHP: high-temperature

(160-180 ºC) PBI-based PEMFC system running on natural gas reformate at

ηelec = 30% and ηCHP = 85%

– Inadequate costs and durability ($10000/kWe at currently 2000 hrs durability)

• Ballard Power Systems with others developing Ballard’s FC-Gen 1300 for

back-up power in Asian markets (India)

– up to 3 kWe powered by natural gas or LPG, ηelec > 30%

http://www.plugpower.com/userfiles/file/GenSysHT-03-09.pdfPapageorgopoulos (DOE) 2010


College Park, MD

Feasibility of SOFC Hydrocarbon-Fueled Auxiliary

Power Unit for Large Trucks

from Scheffer , Delphi, Fuel Cell Seminar 2007


College Park, MD

Making H2 for Fuel Cells: Possible Pathways

Hydrogen

SourcesLiquid Fuels

Hydrogen

Separation

NaturalGas

BiomassWater

Electrolysis

Partial Oxidation

Autothermal Reforming

Steam Reforming

Fuel Decomposition

Hydrogen

PurificationMembrane Technology

PSATechnology

Electrochemical Separation

Preferential Oxidation

Hydrogen

DistributionPipeline

Distributed Generation

On-Demand Generation

Electrolysis

Fuel

TreatmentSulfur

Removal

Truck Delivery LH2

Fuel Refinement

Hydrogen

StorageCompressed

ContainerCryogenic

LiquidMetal

HydrideChemically

Bound

Cryogenics

Carbon Nanotubes

from Santosh Limaye (2005),

consultant for Oak Ridge Natl. Lab

95% of H2 produced today,

efficiency between 70-80%

95% of H2 derived from NG


College Park, MD

Solar Energy

Heat

Hydrogen

Thermolysis

Mechanical Energy

Electricity

Electrolysis

Biomass

Conversion

Photolysis

Sustainable Paths to Hydrogenfrom John Turner, NREL 2006


College Park, MD

Fuel Cells for Cars: Well to Wheel Issues

Fuel Cell

Fuel

Supply

Fuel

Processor

Hydrogen

Clean-UpCombustor

Hydrogen

StorageAir

Oxygen

Enrichment

Waste

CO, CO2, H2, N2, H2O

ΔH<5 ppm CO

Exhaust

Exhaust

Exhaust

Other Thermal & Water Management Systems not shown

from Santosh Limaye (2005),

consultant for Oak Ridge Natl. Lab

• GREET Model from Argonne Natl. Lab

for Well-to-Wheel analysis


College Park, MD

87 kg Total Wt

166 L (5.9 ft3)

Composite Cylinders

@ 700 bar

390 kg Total Wt 340

L (12 ft3)

Commercial Gas

Cylinders @ 180 bar

50 kg Total Wt

46 L ( 1.6 ft3)

Diesel Fuel + Reformer

Diesel Fuel

Storage of 4.0kg of Hydrogen = 60kw-hrs (electric )

Storing H2 for Portable and Distributed Power


College Park, MD

Catalytic Fuel Reforming of Natural Gas to Make H2

• Endothermic Steam Reforming (SR)–Gives highest concentration of H2 out (up to 70% H2)

CH4 + H2O + 20.6 kJ/gmol → CO + 3H2

Heat must be added indirectly, usually by burning fuel.

CH4 + 2*O2 → CO2 + 2*H2O + 80.2 kJ/mgol

Water-gas shift drives further H2 production

CO + H2O ↔ CO2 + H2 + 4.1 kJ/mgol

• Thermally Neutral Auto-thermal Reforming (ATR)CH4 + ½O2 + ½H2O → CO2 + 2½H2 +19.8 kJ/gmol

CO + H2O ↔ CO2 + H2 + 4.1 kJ/gmol

• Exothermic Partial Oxidation (POx)

– Gives lower concentration of H2 out due to N2 dilution from air

CH4 + O2 = CO + 2H2 + 31.9 kJ/gmol

All Heats of reaction at 300 K


College Park, MD

DOE Projected Near and Long Term H2 Dispensed

Costs (Satyapal 2011)


College Park, MD

Challenge of H2 Storage and Distribution• Renewable pure H2 production from a variety of sources now requires means

of storing H2 on vehicles or at power sites.

• Current-day technology requires H2 storage as gas in high-pressure

composite tanks with pressures at 350 to 700 bar.

– Safety concerns with high pressures and significant costs for tank

– Range of high-end fuel cell vehicles approaching best IC engine cars.

– Local compression to fill tanks

• Shipping is only easily done in pipelines and such infrastructure is not

economical.

• Local compression to fill tanks can be done quickly but with a substantial

pump-to-car inefficiency.

• Possibility of shipping around renewable or nuclear electricity to do

electrolysis (need to develop higher efficiency, high-T electrolysis).

• Costs for natural gas steam reforming supply in 100 largest metropolitan

areas and along every interstate range from $12B up to $100B+

– Not long-term solution but transition technology to renewable sources for H2.

• Value of H2 does not need to be in energy efficiency, but in security and

greenhouse gas reductions


College Park, MD

DOE Hydrogen Storage Targetsfrom Catherine Grégoire Padró of Los Alamos National Laboratory


College Park, MD

H2 Safety Considerations

• Steel embrittlement.

• For vehicles, gas storage pressures range from 5,000 to 10,000 psi

• Highest volumetric leak propensity of any fuel.

• Permeation leaks.

• Smallest ignition energy of any fuel in air (28 J).

• Lowest autoignition temperature of any fuel in heated air jet (640 °C).

• Wide flammability limits in air (4 – 75% by volume).

• Highest laminar burning velocity of any fuel which can transition to

detonations in very crowded spaces.

• Smallest quenching distance of any fuel premixed with air (0.51 mm).

• Highest heat of combustion (120 kJ/g).

• Dimmest flames of any fuel in air.


College Park, MD

H2 Safety Considerations

• Status of H2 vehicles and fueling stations in U.S.

• Selected U.S. H2 vehicle demonstration programs.

• SAE J2578 – Recommended Practice for General Fuel Cell Vehicle

Safety.

‒ Required H2 below 25% of the lean flammability limit in air

‒ Maximum release in accident or system failure is 7370 standard liters

of H2

• SAE J2579 – Technical Information Report for Fuel Systems in Fuel

Cells and Other H2 Vehicles.

• SAE J2601 – Technical Information Report for Fueling Protocols for

Light Duty Gaseous H2 Surface Vehicles.

• Other U.S. standards – NFPA 2, “H2 Technologies Code” NFPA


College Park, MD

Closing Thoughts: Perspective on Fuel Cells

• Fuel cell stack costs have dropped dramatically in the past decade but

– Stacks costs remain high for SOFC’s (~$175/kW) and for PEMFC’s (~$60/kW)

but have fallen enough that high balance of plant and/or fuel processor costs

may not be prohibitive for some key markets including

• Distribute power with CHP, back-up power

• Truck APU’s

• Urban bus fleets

• Materials handling.

• Materials advances in areas like high-temp PEMFCs (150 to 200 °C) and

lower-temperature SOFCs (500 to 650 °C) are needed for these promising

technologies to provide adequate durability and cost effectiveness to

perhaps open up broader markets.

• Some available fuels (such as ethanol) may be very favorable for fuel cell

power plants

• Government need not be the only source of funding for these nearer term

markets.

• Government is still needed to drive the infrastructure and long-term

investment needed for H2 vehicles and H2 production from renewable energy.

Hydrogen Technology for Vehicles: Potential and Challenges

Documents

Transcript of Hydrogen Technology for Vehicles: Potential and Challenges