Fuel Cells - Green Power - PDHonline.com · for Fuel Cells 24. Hydrogen as A Fuel 27. Getting To...

PDHonline Course E196 (3 PDH)

Fuel Cells - New Energy for the Future

Instructor Jeffrey Havelin PE

2012

PDH Online | PDH Center5272 Meadow Estates Drive

Fairfax VA 22030-6658Phone amp Fax 703-988-0088

wwwPDHonlineorgwwwPDHcentercom

An Approved Continuing Education Provider

The authors acknowledge the following reviewers

Los Alamos National LaboratoryShimshon GottesfeldCharles F KellerSteffen MOslashller-HolstAntonio Redondo

Office of Advanced Automotive TechnologiesUS Department of Energy

JoAnn Milliken

LA-UR-99-3231

Los Alamos National Laboratory an affirmativeactionequal opportunity employer is operatedby the University of California for the USDepartment of Energy under contract W-7405-ENG-36 All company names logos and productsmentioned herein are trademarks of theirrespective companies Reference to any specificcompany or product is not be construed as anendorsement of said company or product by theRegents of the University of California theUnited States Government the US Department ofEnergy nor any of their employees The LosAlamos National Laboratory strongly supportsacademic freedom and a researcherrsquos right topublish as an institution however theLaboratory does not endorse the viewpoint of apublication or guarantee its technical correctness

1

ndash Green Power

Whatrsquos Inside

2 A Brief History

4 The Very Basicsand More

5 SomeComparisons

7 The Polymer ElectrolyteMembrane Fuel Cell

15 Other Typesof Fuel Cells

19 What About Fuel

21 Applicationsfor Fuel Cells

24 Hydrogen as A Fuel

27 Getting To CleanerTransportation

28 Oil ReservesTransportationand Fuel Cells

29 Climate ChangeGreenhouse Gasesand Fuel CellsWhat is the Link

32 A Once-In-A-LifetimeOpportunity

Fuel Cells ndash Green Powerwas written by Sharon Thomasand Marcia Zalbowitz atLos Alamos National Laboratoryin Los Alamos New Mexico

Designed by Jim Cruz

This publication has been funded by the

Office of Advanced Automotive TechnologiesOffice of Transportation TechnologiesEnergy Efficiency and Renewable EnergyUS Department of Energy

The 3M Foundation

For more informationwwweducationlanlgovresourcesfuelcells

Lamps burning coaloil and coal gas litthe living rooms ofmost homes of theearly 1900rsquos Butwhen electric lightbulbs replaced thosesmoky smellysources of illumina-tion homes becamebrighter cleaner andsafer At first onlythe wealthy couldafford electric lightsBut as the demandwent up and the costwent down moreand more of thepopulation were ableto afford electriclighting even thoughthere was plentyof coal to continuelighting buildings inthe usual way Thebetter technologywon

DS Scott and W HafeleldquoThe Coming HydrogenAge Preventing WorldClimate DisruptionrdquoInternational Journal ofHydrogen Energy Vol15 No 10 1990

A Brief History

A lthough fuel cells have been around since 1839 it took 120 yearsuntil NASA demonstrated some of their potential applications in

providing power during space flight As a result of these successes inthe 1960s industry began to recognize the commercial potential offuel cells but encountered technical barriers and high investment costsmdash fuel cells were not economically competitive with existing energytechnologies Since 1984 the Office of Transportation Technologies atthe US Department of Energy has been supporting research anddevelopment of fuel cell technology and as a result hundreds ofcompanies around the world are now working towards making fuelcell technology pay off Just as in the commercialization of the electriclight bulb nearly one hundred years ago todayrsquos companies arebeing driven by technical economic and social forces such as highperformance characteristics reliability durability low cost andenvironmental benefits

In 1839 William Grove a British jurist and amateur physicist first discovered theprinciple of the fuel cell Grove utilized four large cells each containing hydrogenand oxygen to produce electric power which was then used to split the water inthe smaller upper cell into hydrogen and oxygen

ldquoI cannot but regard the experiment as an important onerdquo

William Grove writing to Michael FaradayOctober 22 1842

3

ldquoThe mission of our global fuel cell project center is nothing less than to make us the leader in

commercially viable fuel cell powered vehiclesrdquo

Harry J Pearce Vice ChairmanBoard of Directors General MotorsMay 1998

In March 1998 Chicago became the firstcity in the world to put pollution-freehydrogen fuel cell powered buses intheir public transit system(Courtesy Ballard Power Systems)

The FutureCar Challenge sponsored bythe US Department of Energy presentsa unique assignment to students fromNorth Americarsquos top engineering schoolsconvert a conventional midsize sedaninto a super efficient vehicle withoutsacrificing performance utility andsafety In 1999 the Virginia Techteam entered the competition with afuel cell vehicle

The first fuel cell powered bicycleto compete in the American Tour-de-Sol(Courtesy H-Power)

The automobile it is fair to say changed the industrial andsocial fabric of the United States and most

countries around the globe Henry Ford epitomized ldquoYankee ingenuityrdquoand the Model T helped create the open road new horizons abundant andinexpensive gasolineand tailpipe exhaust More people are driving morecars today than ever before mdash more than 200 million vehicles are on the roadin the US alone But the car has contributed to our air and water pollutionand forced us to rely on imported oil from the Middle East helping to createa significant trade imbalance Today many people think fuel cell technologywill play a pivotal role in a new technological renaissance mdash just as theinternal combustion engine vehicle revolutionized life at the beginning ofthe 20th century Such innovation would have a global environmental andeconomic impact

ldquoIn todayrsquos worldsolving environmental problems

is an investment not an expenserdquo

William Clay Ford JrChairman and CEO Ford Motor CompanySeptember 1998

Fuel cells are not just laboratory curiosities While there is much work thatneeds to be done to optimize the fuel cell system (remember the gasolineinternal combustion engine is nearly 120 years old and still being improved)hydrogen fuel cell vehicles are on the road mdash now Commuters living inChicago and Vancouver ride on fuel cell buses You can take a ride aroundLondon in a fuel cell taxi and even compete in the American Tour de Solon a fuel cell bicycle Every major automobile manufacturer in the world is developing fuel cell vehicles To understand why fuel cells have receivedsuch attention we need to compare them to existing energy conversiontechnologies

Where the Actionin Fuel Cells is Today

Allied SignalVolvoBallardDaimlerChryslerDetroit EdisonDuPontShellFordGeneral MotorsHondaMazdaGeorgetown UniversityCase Western Reserve UniversityLos Alamos National LaboratoryMotorolaPenn State UniversityPrinceton UniversityRolls-RoyceArgonne National LaboratorySanyoDAISSiemensBritish GasPlug PowerUniversity of MichiganTexas AampM UniversityARCOEpyxInternational Fuel CellsH-PowerEnergy PartnersHydrogen BurnerWL GoreAD LittleInstitute of Gas TechnologyVairexElectrochemGinerJet Propulsion LaboratoryToyotaUniversity of CaliforniaExxonWestinghouseRenault3MNissanBMWPSA Peugeot CitroeumlnTexacoUniversity of FloridaTokyo Electric Power

(This is just a partial l ist)

Carnot Cycle vs Fuel Cells

T he theoretical thermodynamic derivation of Carnot Cycle showsthat even under ideal conditions a heat engine cannot convert all

the heat energy supplied to it into mechanical energy some of theheat energy is rejected In an internal combustion engine the engineaccepts heat from a source at a high temperature (T1) converts part ofthe energy into mechanical work and rejects the remainder to a heatsink at a low temperature (T2) The greater the temperature differencebetween source and sink the greater the efficiency

Maximum Efficiency = (T1 ndash T2) T1

where the temperatures T1 and T2 are given in degrees KelvinBecause fuel cells convert chemical energy directly to electrical energythis process does not involve conversion of heat to mechanical energyTherefore fuel cell efficiencies can exceed the Carnot limit even whenoperating at relatively low temperatures for example 80degC

The Very Basics

bull A fuel cell is an electrochemical energyconversion device It is two to threetimes more efficient than an internalcombustion engine in converting fuelto power

bull A fuel cell produces electricity waterand heat using fuel and oxygen in theair

bull Water is the only emission whenhydrogen is the fuel

As hydrogen flows into the fuel cell onthe anode side a platinum catalyst facili-tates the separation of the hydrogen gas

into electrons and protons (hydrogen ions) The hydrogen ions passthrough the membrane (the center of the fuel cell) and again with thehelp of a platinum catalyst combine with oxygen and electrons on thecathode side producing water The electrons which cannot passthrough the membrane flow from the anode to the cathode through anexternal circuit containing a motor or other electric load which con-sumes the power generated by the cell

The voltage from one single cell is about 07 volts ndash just about enoughfor a light bulb ndash much less a car When the cells are stacked in seriesthe operating voltage increases to 07 volts multiplied by the numberof cells stacked

Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5

W hat internal combustionengines batteries and fuel

cells have in common is theirpurpose all are devices that convertenergy from one form to anotherAs a starting point letrsquos consider theinternal combustion engine mdash usedto power virtually all of the carsdriven on US highways todayThese engines run on noisy hightemperature explosions resultingfrom the release of chemical energyby burning fuel with oxygen fromthe air Internal combustion en-gines as well as conventional utilitypower plants change chemicalenergy of fuel to thermal energy togenerate mechanical and in the caseof a power plant electrical energyFuel cells and batteries are electro-chemical devices and by their verynature have a more efficient conver-sion process chemical energy isconverted directly to electricalenergy Internal combustion enginesare less efficient because they includethe conversion of thermal to me-chanical energy which is limited bythe Carnot Cycle

If cars were powered by electricitygenerated from direct hydrogen fuelcells there would be no combustioninvolved In an automotive fuel cellhydrogen and oxygen undergo arelatively cool electrochemicalreaction that directly produceselectrical energy This electricitywould be used by motors includingone or more connected to axles usedto power the wheels of the vehicleThe direct hydrogen fuel cell vehiclewill have no emissions even duringidling mdash this is especially importantduring city rush hours There are

How do Fuel Cells Compare toInternal Combustion Engines and Batteries

some similarities to an internalcombustion engine however Thereis still a need for a fuel tank andoxygen is still supplied from the air

Many people incorrectly assume thatall electric vehicles (EVs) are pow-ered by batteries Actually an EV isa vehicle with an electric drive trainpowered by either an on-boardbattery or fuel cell Batteries andfuel cells are similar in that theyboth convert chemical energy intoelectricity very efficiently and theyboth require minimal maintenancebecause neither has any movingparts However unlike a fuel cellthe reactants in a battery are storedinternally and when used up thebattery must be either recharged orreplaced In a battery-powered EVrechargeable batteries are usedWith a fuel cell powered EV the fuelis stored externally in the vehiclersquos

fuel tank and air is obtained fromthe atmosphere As long as thevehiclersquos tank contains fuel the fuelcell will produce energy in the formof electricity and heat The choiceof electrochemical device battery orfuel cell depends upon use Forlarger scale applications fuel cellshave several advantages over batter-ies including smaller size lighterweight quick refueling and longerrange

The polymer electrolyte membrane(PEM) fuel cell is one in a family offive distinct types of fuel cells ThePEM fuel cell under considerationby vehicle manufacturers around theworld as an alternative to theinternal combustion engine will beused to illustrate the science andtechnology of fuel cells

The P2000 from Ford Motor Company is a zero-emission vehicle that utilizes a directhydrogen polymer electrolyte fuel cell (Courtesy of Ford Motor Co)

Hydrogen Fuel Cell Car

Chemical Energy(gaseous flow) Electrical Energy

FuelCells Hydrogen

Tank

Mechanical Energy

TractionInverterModule

Turbo-compressor

Hydrogen issupplied to the Fuel Cells

Air is supplied tothe fuel cells byturbocompressor

The traction inverter moduleconverts the electricity foruse by the electric motortransaxles

The electric motortransaxle converts theelectric energy into themechanical energywhich turns the wheels

Oxygen from the air andhydrogen combine in thefuel cells to generate electricitythat is sent to the tractioninverter module

ElectricMotor

Transaxle

References

Bill McKibben ldquoA Special Moment inHistoryrdquo The Atlantic MonthlyMay 1998

James J MacKenzie ldquoOil as a FiniteResource When is GlobalProduction Likely to PeakrdquoWorld Resources Institute March1996

Colin Campbell and Jean H LaherrereldquoThe End of Cheap Oil rdquo ScientificAmerican March 1998

ldquoBusting Through with BallardrdquoFinancial Times EnergyWorld Number Five Winter1998

Jacques Leslie ldquoThe Dawn of theHydrogen Agerdquo Wired October1997

McGraw-Hill Dictionary of Scientificand Technical Terms 1994

Motor Vehicle Facts and FiguresAmerican AutomobileManufacturers Association 1998

Resources

World Resources Institutehttpwwwwriorg

International Fuel Cellshttpwwwhamilton-standardcomifc-onsi

United Nations Framework Conventionon Climate Changehttpwwwunfcccde

Linkages httpwwwiisdcalinkages

Environmental Protection AgencyAlternative Fuelshttp wwwepagovomswww

US Fuel Cell Councilhttpwwwusfcccom

Fuel Cells 2000httpfuelcellsorg

Future Opportunities

Polymer electrolyte membrane fuel cells arelimited by the temperature range over whichwater is a liquid The membrane must containwater so that the hydrogen ions can carry thecharge within the membrane Operating poly-mer electrolyte membrane fuel cells attemperatures exceeding 100˚C is possibleunder pressurized conditions required to keepthe water in a liquid state but shortens thelife of the cell Currently polymer electrolytemembranes cost about $100square footCosts are expected to decrease significantlyas the consumer demand for polymer electro-lyte membrane fuel cells increases

Remaining Challenges

bull producing membranes not limited by thetemperature range of liquid waterpossibly based on another mechanism forprotonic conduction

bull reducing membrane cost by developingdifferent membrane chemistries

Structure of Polymer Electrolyte Membranes

T he polymer electrolyte membrane is a solid organic polymerusually poly[perfluorosulfonic] acid A typical membrane material

such as NafionTM consists of three regions

(1) the Teflon-like fluorocarbon backbone hundreds of repeating ndash CF2 ndash CF ndash CF2 ndash units in length

(2) the side chains ndashOndash CF2 ndash CF ndash Ondash CF2 ndash CF2 ndash which connect themolecular backbone to the third region

(3) the ion clusters consisting of sulfonic acid ions SO3- H+

The negative ions SO3- are permanently attached to the side chain

and cannot move However when the membrane becomes hydratedby absorbing water the hydrogen ions become mobile Ion movementoccurs by protons bonded to water molecules hopping from SO3

- siteto SO3

- site within the membrane Because of this mechanism thesolid hydrated electrolyte is an excellent conductor of hydrogen ions

ndash CF2 ndash CF ndash CF2 ndash lO lCF2 lCF ndash CF3 lO lCF2 lCF2 lSO3

- H+

Chemical structureof membranematerialNafionTM by DuPont

Definitions

Electrochemical reaction A reactioninvolving the transfer ofelectrons from one chemicalsubstance to another

Fuel cell An electrochemical devicethat continuously converts thechemical energy of externallysupplied fuel and oxidant directlyto electrical energy

Oxidant A chemical such as oxygenthat consumes electrons in anelectrochemical reaction

Electrolyte A substance composed ofpositive and negative ions

Ion An atom that has acquired anelectrical charge by the loss or gainof electrons

1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m

Polymer A substance made of giantmolecules formed by the union ofsimple molecules (monomers)

Thermal Pertaining to heat

7

A s little as 10 years ago vehicles powered byfuel cells seemed more science fiction than fact

Today development of fuel cell technology for transpor-tation is made possible due to the polymer electrolytemembrane fuel cell This type of fuel cell is also knownas the proton exchange membrane fuel cell the solidpolymer electrolyte (SPETM) fuel cell and simply poly-mer electrolyte fuel cell It is often referred to simply asthe ldquoPEMrdquo fuel cell The center of the fuel cell is thepolymer electrolyte membrane For all five families offuel cells it is the electrolyte that defines the type of fuelcell so the discussion of the polymer electrolyte mem-brane fuel cell should logically begin with its electrolytethe membrane

The Polymer Electrolyte Membrane

An ordinary electrolyte is a substance that dissociatesinto positively charged and negatively charged ions inthe presence of water thereby making the water solu-tion electrically conducting The electrolyte in apolymer electrolyte membrane fuel cell is a type ofplastic a polymer and is usually referred to as a mem-brane The appearance of the electrolyte variesdepending upon the manufacturer but the most preva-lent membrane Nafion TM produced by DuPontresembles the plastic wrap used for sealing foods Typi-cally the membrane material is more substantial thancommon plastic wrap varying in thickness from 50 to175 microns To put this in perspective consider that apiece of normal writing paper has a thickness of about 25microns Thus polymer electrolyte membranes havethicknesses comparable to that of 2 to 7 pieces of paperIn an operating fuel cell the membrane is well humidi-fied so that the electrolyte looks like a moist piece ofthick plastic wrap

Polymer electrolyte membranes are somewhat unusualelectrolytes in that in the presence of water which themembrane readily absorbs the negative ions are rigidlyheld within their structure Only the positive ionscontained within the membrane are mobile and are free

to carry positive charge through the membrane Inpolymer electrolyte membrane fuel cells these positiveions are hydrogen ions or protons hence the term ndashproton exchange membrane Movement of the hydro-gen ions through the membrane in one direction onlyfrom anode to cathode is essential to fuel cell operationWithout this movement of ionic charge within the fuelcell the circuit defined by cell wires and load remainsopen and no current would flow

Because their structure is based on a TeflonTM backbonepolymer electrolyte membranes are relatively strongstable substances Although thin a polymer electrolytemembrane is an effective gas separator It can keep thehydrogen fuel separate from the oxidant air a featureessential to the efficient operation of a fuel cell Al-though ionic conductors polymer electrolytemembranes do not conduct electrons The organicnature of the polymer electrolyte membrane structuremakes them electronic insulators another featureessential to fuel cell operation As electrons cannotmove through the membrane the electrons produced atone side of the cell must travel through an externalwire to the other side of the cell to complete the circuitIt is in their route through the circuitry external to thefuel cell that the electrons provide electrical power torun a car or a power plant

The Polymer Electrolyte Membrane Fuel Cell

The Electrodes

All electrochemical reactions consist of two separate reactions an oxidation half-reaction occurring at the anode anda reduction half-reaction occurring at the cathode The anode and the cathode are separated from each other by theelectrolyte the membrane

In the oxidation half-reaction gaseous hydrogen produces hydrogen ions which travel through the ionically con-ducting membrane to the cathode and electrons which travel through an external circuit to the cathode In thereduction half-reaction oxygen supplied from air flowing past the cathode combines with these hydrogen ions andelectrons to form water and excess heat These two half-reactions would normally occur very slowly at the lowoperating temperature typically 80˚C of the polymer electrolyte membrane fuel cell Thus catalysts are used onboth the anode and cathode to increase the rates of each half-reaction The catalyst that works the best on eachelectrode is platinum a very expensive material

The final products of the overall cell reaction are electric power water and excess heat Cooling is required in factto maintain the temperature of a fuel cell stack at about 80˚C At this temperature the product water produced atthe cathode is both liquid and vapor This product water is carried out of the fuel cell by the air flow

Electrochemistry of Fuel Cells

Oxidation half reaction 2H2 4H+ + 4e-

Reduction half reaction O2 + 4H+ + 4e- 2H2O

Cell reaction 2H2 + O2 2H2O

T he physical and electrochemical processes that occur at eachelectrode are quite complex At the anode hydrogen gas (H2)

must diffuse through tortuous pathways until a platinum (Pt) particleis encountered The Pt catalyzes the dissociation of the H2 moleculeinto two hydrogen atoms (H) bonded to two neighboring Pt atomsOnly then can each H atom release an electron to form a hydrogen ion(H+) Current flows in the circuit as these H+ ions are conductedthrough the membrane to the cathode while the electrons pass fromthe anode to the outer circuit and then to the cathode

The reaction of one oxygen (O2) molecule at the cathode is a 4electron reduction process (see above equation) which occurs in amulti-step sequence Expensive Pt based catalysts seem to be theonly catalysts capable of generating high rates of O2 reduction at therelatively low temperatures (~ 80˚C) at which polymer electrolytemembrane fuel cells operate There is still uncertainty regarding themechanism of this complex process The performance of the polymerelectrolyte membrane fuel cells is limited primarily by the slow rate ofthe O2 reduction half reaction which is more than 100 times slowerthan the H2 oxidation half reaction

DefinitionsCatalyst A substance that

participates in a reactionincreasing its rate but is notconsumed in the reaction

Current The flow of electric chargethrough a circuit

Electrode An electronic conductorthrough which electrons areexchanged with the chemicalreactants in an electrochemical cell

Electron An elementary particlehaving a negative charge

1 nanometer = 10-9 m = 10-7 cm= 10-6 mm = 10-3 microm = 1 nm

Oxidation half reaction A process inwhich a chemical species changes toanother species with a morepositive charge due to the releaseof one or more electrons It canoccur only when combined with areduction half reaction

Reduction half reaction A process inwhich a chemical species changesto another species with a lesspositive charge due to theaddition of one or more electronsIt can occur only when combinedwith an oxidation half reaction

9

Polymer electrolyte membrane with porous electrodes thatare composed of platinum particles uniformly supported

on carbon particles

Why a Fuel Cell Goes ldquoPlatinumrdquo

T he half reactions occurring at each electrode can only occur at ahigh rate at the surface of the Pt catalyst Platinum is unique

because it is sufficiently reactive in bonding H and O intermediates asrequired to facilitate the electrode processes and also capable ofeffectively releasing the intermediate to form the final product Forexample the anode process requires Pt sites to bond H atoms whenthe H2 molecule reacts and these Pt sites next release the H atomsas H+ + e-

H2 + 2Pt 2 Pt-H2 Pt ndash H 2 Pt + 2 H+ + 2e-

This requires optimized bonding to H atoms mdash not too weak and nottoo strong mdash and this is the unique feature of a good catalyst Real-izing that the best catalyst for the polymer electrolyte membrane fuelcell is expensive lowering Pt catalyst levels is an on-going effortOne of the best ways to accomplish this is to construct the catalystlayer with the highest possible surface area Each electrode consistsof porous carbon (C) to which very small Pt particles are bonded Theelectrode is somewhat porous so that the gases can diffuse througheach electrode to reach the catalyst Both Pt and C conduct electronswell so electrons are able to move freely through the electrode Thesmall size of the Pt particles about 2 nanometers in diameter resultsin an enormously large total surface area of Pt that is accessible togas molecules The total surface presented by this huge number ofsmall particles is very large even when the total mass of Pt used issmall This large Pt surface area allows the electrode reactions toproceed at many Pt surface sites simultaneously This high dispersionof the catalyst is one key to generating significant electron flow iecurrent in a fuel cell

Water and Fuel Cell Performance

ldquoW ater managementrdquo is key to effective operation of apolymer electrolyte membrane fuel cell Although water

is a product of the fuel cell reaction and is carried out of the cellduring its operation it is interesting that both the fuel and airentering the fuel cell must still be humidified This additional waterkeeps the polymer electrolyte membrane hydrated The humidityof the gases must be carefully controlled Too little water preventsthe membrane from conducting the H+ ions well and the cellcurrent drops

If the air flow past the cathode is too slow the air canrsquot carry allthe water produced at the cathode out of the fuel cell and thecathode ldquofloodsrdquo Cell performance is hurt because not enoughoxygen is able to penetrate the excess liquid water to reach thecathode catalyst sites


bull Impurities often present in the H2 fuelfeed stream bind to the Pt catalystsurface in the anode preventing H2oxidation by blocking Pt catalyst sitesAlternative catalysts which can oxidizeH2 while remaining unaffected byimpurities are needed to improve cellperformance

bull The rate of the oxygen reductionprocess at the air electrode is quite loweven at the best Pt catalysts developedto date resulting in significantperformance loss Alternative catalyststhat promote a high rate of oxygenreduction are needed to further enhancefuel cell performance

bull Future alternative catalysts must be lessexpensive than Pt to lower the cost ofthe cell

9

PolymerElectrolyteMembrane Pathway(s) allowing

conduction of electrons

Pathway(s) allowingconduction of hydrogen ions

Pathway(s) allowingaccess of gas tocatalyst surface

CarbonPlatinum

TheMembraneElectrode

Assembly

T he combination of anodemembranecathode isreferred to as the membraneelectrode assembly

The evolution of membraneelectrode assemblies inpolymer electrolyte membrane fuel cells has passedthrough several generations The original membraneelectrode assemblies were constructed in the 1960s forthe Gemini space program and used 4 milligrams ofplatinum per square centimeter of membrane area(4 mgcm2) Current technology varies with the manu-facturer but total platinum loading has decreased fromthe original 4 mgcm2 to about 05 mgcm2 Laboratoryresearch now uses platinum loadings of 015mgcm2 This corresponds to an improvement in fuel cell perfor-mance since the Gemini program as measured byamperes of current produced from about 05 amperesper milligram of platinum to 15 amperes per milligramof platinum

The thickness of the membrane in a membraneelec-trode assembly can vary with the type of membraneThe thickness of the catalyst layers depends upon howmuch platinum is used in each electrode For catalystlayers containing about 015 mg Ptcm2 the thickness ofthe catalyst layer is close to 10 microns less than half thethickness of a sheet of paper It is amazing that this

membraneelectrode assembly with atotal thickness of about 200 microns or 02millimeters can generate more than halfan ampere of current for every squarecentimeter of membraneelectrode assem-bly at a voltage between the cathode andanode of 07 volts but only when encasedin well engineered components mdash backinglayers flow fields and current collectors

Membraneelectrode assembly


Optimization of membraneelectrodeassembly (MEA) construction is on-goingFundamental research into the catalyst layermembrane interface is needed to furtherunderstand the processes involved in currentgeneration New MEA designs whichwill increase fuel cell performanceare needed As always the science andtechnology of MEAs are interconnectedwhether improved understanding will leadto better MEA design or a different designwill lead to improved understanding remainsto be seen

Making a MembraneElectrode Assembly

M embraneelectrode assembly construction varies greatlybut the following procedure is one of several used at Los

Alamos National Laboratory where fuel cell research is activelypursued The catalyst material is first prepared in liquid ldquoinkrdquoform by thoroughly mixing together appropriate amounts ofcatalyst (a powder of Pt dispersed on carbon) and a solution ofthe membrane material dissolved in alcohols Once the ink isprepared it is applied to the surface of the solid membrane ina number of different ways The simplest method involvespainting the catalyst ldquoinkrdquo directly onto a dry solid piece ofmembrane The wet catalyst layer and the membrane areheated until the catalyst layer is dry The membrane is thenturned over and the procedure is repeated on the other sideCatalyst layers are now on both sides of the membrane Thedry membraneelectrode assembly is next rehydrated byimmersing in lightly boiling dilute acid solution to also ensurethat the membrane is in the H+ form needed for fuel cell opera-tion The final step is a thorough rinsing in distilled water Themembraneelectrode assembly is now ready for insertion intothe fuel cell hardware

02mm

AnodeCathode

Polymer electrolyte membrane

11

TheBacking Layers

T he hardware of the fuel cell backing layersflow fields and current collectors is designed to

maximize the current that can be obtained from amembraneelectrode assembly The so-called backinglayers one next to the anode the other next to thecathode are usually made of a porous carbon paper orcarbon cloth typically 100 to 300 microns thick (4 to 12sheets of paper) The backing layers have to be made ofa material such as carbon that can conduct the electronsexiting the anode and entering the cathode

The porous nature of the backing material ensureseffective diffusion of each reactant gas to the catalyst onthe membraneelectrode assembly In this contextdiffusion refers to the flow of gas molecules from aregion of high concentration the outer side of thebacking layer where the gas is flowing by in the flowfields to a region of low concentration the inner side ofthe backing layer next to the catalyst layer where the gasis consumed by the reaction The porous structure ofthe backing layers allows the gas to spread out as itdiffuses so that when it penetrates the backing the gaswill be in contact with the entire surface area of thecatalyzed membrane

Enlarged cross-section of a membraneelectrode assembly showing structural details

The backing layers also assist in watermanagement during the operation ofthe fuel cell too little or too muchwater can cause the cell to cease opera-tion The correct backing materialallows the right amount of water vaporto reach the membraneelectrodeassembly to keep the membranehumidified The backing material alsoallows the liquid water produced at thecathode to leave the cell so it doesnrsquotldquofloodrdquo The backing layers are oftenwet-proofed with Teflontrade to ensurethat at least some and hopefully mostof the pores in the carbon cloth (orcarbon paper) donrsquot become cloggedwith water which would prevent rapidgas diffusion necessary for a good rateof reaction to occur at the electrodes

Electrode

Pathways forgas accessto electrode

Backing layerBacking layer Membraneelectrode assembly

Cathodebacking

Anodebacking

PolymerElectrolyteMembrane

Membraneelectrode assembly with backing layers

P ressed against the outer surface of each backinglayer is a piece of hardware called a plate which

often serves the dual role of flow field and currentcollector In a single fuel cell these two plates are thelast of the components making up the cell The platesare made of a light-weight strong gas-impermeableelectron-conducting material graphite or metals arecommonly used although composite plates are nowbeing developed

The first task served by each plate is to provide a gasldquoflow fieldrdquo The side of the plate next to the backinglayer contains channels machined into the plate Thechannels are used to carry the reactant gas from thepoint at which it enters the fuel cell to the point atwhich the gas exits The pattern of the flow field in theplate as well as the width and depth of the channels havea large impact on the effectiveness of the distribution ofthe reactant gases evenly across the active area of themembraneelectrode assembly Flow field design alsoaffects water supply to the membrane and water removalfrom the cathode

The second purpose served by each plate is that ofcurrent collector Electrons produced by the oxidationof hydrogen must be conducted through the anodethrough the backing layer and through the plate beforethey can exit the cell travel through an external circuitand re-enter the cell at the cathode plate

With the addition of the flow fields and current collec-tors the polymer electrolyte membrane fuel cell is nowcomplete Only a load-containing external circuit suchas an electric motor is required for electric current toflow the power having been generated by passinghydrogen and air on either side of what looks like apiece of food wrap painted black

The FlowFields Current

Collectors

Photographs of stainless steelflow fieldscurrent collectors

Micrograph of a milled carbon-fibercomposite flow-field Height widthand spacing of channels = 08mm(0032 inch)

A single polymer electrolyte membrane fuel cell

Hydrogenflow field

Air (oxygen)flow field

Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking

Cathodecurrentcollector

Anodecurrent

collector

13

Efficiency Power and Energy of Polymer Electrolyte Membrane Fuel Cell

Energy conversion of a fuel cell can be summarized in the following equation

Chemical energy of fuel = Electric energy + Heat energy

A single ideal H2air fuel cell should provide 116 volts at zero current (ldquoopencircuitrdquo conditions) 80degC and 1 atm gas pressure A good measure of energyconversion efficiency for a fuel cell is the ratio of the actual cell voltage to the theo-retical maximum voltage for the H2air reaction Thus a fuel cell operating at 07 V isgenerating about 60 of the maximum useful energy available from the fuel in theform of electric power If the same fuel cell is operated at 09 V about 775 of themaximum useful energy is being delivered as electricity The remainingenergy (40 or 225) will appear as heat The characteristic performance curvefor a fuel cell represents the DC voltage delivered at the cell terminals as a function ofthe current density total current divided by area of membrane being drawn from thefuel cell by the load in the external circuit

The power (P) expressed in units of watts delivered by a cell is the product of the current (I) drawn and the terminal voltage (V) at that cur-rent (P = IV) Power is also the rate at which energy (E) is made available (P = Et) or conversely energy expressed in units of watt-hours isthe power available over a time period (t) (E = Pt) As the mass and volume of a fuel cell system are so important additional terms are alsoused Specific power is the ratio of the power produced by a cell to the mass of the cell power density is the ratio of the power produced by acell to the volume of the cell High specific power and power density are important for transportation applications to minimize the weight andvolume of the fuel cell as well as to minimize cost

Derivation of Ideal Fuel Cell Voltage

Prediction of the maximum available voltage from a fuel cell process involves evaluation of energy differences between the initial state of reac-tants in the process (H2 +12 O2) and the final state (H2O) Such evaluation relies on thermodynamic functions of state in a chemical processprimarily the Gibbs free energy The maximum cell voltage ( E) for the hydrogenair fuel cell reaction ( H2 + 12 O2 H2O) at a specific tem-perature and pressure is calculated [ E = - GnF] where G is the Gibbs free energy change for the reaction n is the number of moles ofelectrons involved in the reaction per mole of H2 and F is Faradayrsquos constant 96 487 coulombs (joulesvolt) the charge transferred per moleof electrons

At a constant pressure of 1 atmosphere the Gibbs free energy change in the fuel cell process (per mole of H2) is calculated from the reactiontemperature (T) and from changes in the reaction enthalpy ( H) and entropy ( S)

G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J

For the hydrogenair fuel cell at 1 atmosphere pressure and 25˚C (298 K) the cell voltage is 123 VE = - GnF

= - (-237200 J2 x 96487 JV)= 123 V

As temperature rises from room temperature to that of an operating fuel cell (80˚C or 353 K) the values of H and S change only slightlybut T changes by 55˚ Thus the absolute value of G decreases For a good estimation assuming no change in the values of H and S

G = - 285800 Jmol ndash (353 K)(-1632 Jmol K)= - 228200 Jmol

Thus the maximum cell voltage decreases as well (for the standard case of 1 atm) from 123 V at 25˚C to 118 V at 80˚CE = - (-228200 J2 x 96487 JV)

= 118 VAn additional correction for air instead of pure oxygen and using humidified air and hydrogen instead of dry gases further reduces themaximum voltage obtainable from the hydrogenair fuel cell to 116 V at 80˚C and 1 atmosphere pressure

13

0

Current Density (mAcm2)

Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll

Graph of voltage vs current density of a hydrogenairpolymer electrolyte membrane fuel cell

Rate of Heat Generation in an Operating Fuel Cell

Assume a 100 cm2 fuel cell is operating under typical conditionsof 1 atmosphere pressure and 80˚C at 07 V and generating

06 Acm2 of current for a total current of 60 A The excessheat generated by this cell can be estimated as follows

Power due to heat = Total power generated ndash Electrical powerPheat = Ptotal ndash Pelectrical

= (Videal x Icell) ndash (Vcell x Icell)= (Videal ndash Vcell) x Icell= (116 V ndash 07 V) x 60 A= 046 V x 60 coulombssec x 60 secondsmin= 1650 Jmin

This cell is generating about 17 kJ of excess heat every minuteit operates while generating about 25 kJ of electric energyper minute

S ince fuel cells operate at less than 100 efficiencythe voltage output of one cell is less than 116 volt

As most applications require much higher voltages thanthis (for example effective commercial electric motorstypically operate at 200 ndash 300 volts) the required voltageis obtained by connecting individual fuel cells in series toform a fuel cell ldquostackrdquo If fuel cells were simply lined-upnext to each other the anode and cathode currentcollectors would be side by side To decrease the overallvolume and weight of the stack instead of two currentcollectors only one plate is used with a flow field cutinto each side of the plate This type of plate called aldquobipolar platerdquo separates one cell from the next withthis single plate serving to carry hydrogen gas on oneside and air on the other It is important that the bipolarplate is made of gas-impermeable material Otherwisethe two gases would intermix leading to direct oxidationof fuel Without separation of the gases electrons passdirectly from the hydrogen to the oxygen and theseelectrons are essentially ldquowastedrdquo as they cannot berouted through an external circuit to do useful electricalwork The bipolar plate must also be electronicallyconductive because the electrons produced at the anodeon one side of the bipolar plate are conducted throughthe plate where they enter the cathode on the other sideof the bipolar plate Two end-plates one at each end ofthe complete stack of cells are connected via the externalcircuit

In the near term different manufacturers will provide avariety of sizes of fuel cell stacks for diverse applicationsThe area of a single fuel cell can vary from a few squarecentimeters to a thousand square centimeters A stackcan consist of a few cells to a hundred or more cellsconnected in series using bipolar plates For applicationsthat require large amounts of power many stacks can beused in series or parallel combinations

A 3 cell fuel cell stack with two bipolar plates and two end plates

The PolymerElectrolyte Membrane

Fuel Cell Stack

Polymer electrolyte membrane fuel cell stack(Courtesy Energy Partners)

End-plateEnd-plate Bipolar plates

Hydrogenflow fields

Airflow fields

e- e-

15

T here are several other types of polymer electrolytemembrane fuel cells for transportation applications

although none have reached the same stage of develop-ment and simplicity as the hydrogenair

ReformateAir Fuel Cell

In addition to the direct hydrogen fuel cell research iscurrently underway to develop a fuel cell system thatcan operate on various types of hydrocarbon fuels mdashincluding gasoline and alternative fuels such as metha-nol natural gas and ethanol Initially this fuel-flexiblefuel strategy will enable reformateair fuel cell systemsto use the exisiting fuels infrastructure A hydrogenairpolymer electrolyte membrane fuel cell would be fueledfrom an onboard reformer that can convert these fuelsinto hydrogen-rich gas mixtures Processing hydrocar-bon fuels to generate hydrogen is a technical challengeand a relatively demanding operation

Hydrocarbon fuels require processing temperatures of700˚C - 1000˚C Sulfur found in all carbon-based fuelsand carbon monoxide generated in the fuel processormust be removed to avoid poisoning the fuel cellcatalyst Although the reformateair fuel cell lacks thezero emission characteristic of the direct hydrogen fuelcell it has the potential of lowering emissions signifi-cantly vs the gasoline internal combustion engine Thenear-term introduction of reformateair fuel cells isexpected to increase market acceptance of fuel celltechnology and help pave the way for the widespreaduse of direct hydrogen systems in the future

Other Types of Polymer Electrolyte Membrane

Fuel Cell Systems

Computer model of 50kW fuel cell stack with reformer(Courtesy International Fuel Cells)

Processing Hydrocarbon Fuels into Hydrogen

As long as hydrogen is difficult to store on a vehicle on-boardfuel processors will be needed to convert a hydrocarbon fuel

such as methanol or gasoline to a H2 rich gas for use in the fuelcell stack Currently steam reforming of methanol to H2 is theconventional technology although partial oxidation of gasoline toH2 is attractive because of the gasoline infrastructure already inplace in most countries Both types of fuel processors are complexsystems

The steam reforming of methanol involves the reaction of steamand pre-vaporized methanol at 200˚C (gasoline requires tempera-tures over 800˚C) to produce a mixture of H2 carbon dioxide(CO2) carbon monoxide (CO) and excess steam This mixturepasses through another reactor called a shift reactor which usescatalysts and water to convert nearly all of the CO to CO2 as wellas additional H2 There can be a third stage in which air is in-jected into the mixture in a third type of reactor the preferentialoxidation reactor Oxygen in the air reacts with the remaining COover a Pt-containing catalyst to convert CO to CO2 The final gasmixture contains about 70 H2 24 CO2 6 nitrogen (N2)and traces of CO

With the partial oxidation reformer system liquid fuel is firstvaporized into a gas The gas is then ignited in a partial oxidationreactor which limits the amount of air so that primarily H2 COand CO2 are produced from the combustion This mixture ispassed through a shift reactor to convert the CO to CO2 and thenthrough a preferential oxidation reactor to convert any remainingCO to CO2 Conventional partial oxidation takes place at~1000˚C and catalytic partial oxidation takes place at ~700˚CThe final reformate composition is about 42 N2 38 H218 CO2 less than 2 CH4 and traces of CO

Diagram of reformateair fuel cell ldquoenginerdquo utilizing liquid methanol as fuel

Hydrogen (H2) CO2and H2

Cooling pump

Fresh Air

Coolingair out

Coolingair in

Water producedby fuel cells

Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank

The Fuel Cell Engine

F uel cell stacks need to be integrated into a complete fuel cellengine A fuel cell engine must be of appropriate weight and

volume to fit into the space typically available for car engines Impor-tantly the operation of the entire engine must maintain the near zeroemissions and high efficiency of fuel cells Finally all these require-ments must be met with components that are both inexpensive anddesigned for low cost high volume manufacturing

References

Fuel Cell Handbook on CD(4th Edition) US Department ofEnergy Office of Fossil EnergyFederal Energy TechnologyCenter November 1998

CE (Sandy) Thomas etalIntegrated Analysis of HydrogenPassenger VehicleTransportation PathwaysNational Renewable EnergyLaboratory March 1998

Shimshon Gottesfeld PolymerElectrolyte Fuel Cells Advancesin Electrochemical Science andEngineering Vol5 Wiley-VCH1997

Fritz R Kalhammer et al Statusand Prospects of Fuel Cells asAutomotive Engines Preparedfor the State of California AirResources Board July 1998

Regenerative Fuel Cell SystemTestbed Program for Governmentand Commercial ApplicationshttpwwwlercnasagovwwwRT199550005420phtm

Solar-Powered Plane Flies to NewRecord Height mdash One StepCloser to a Commercial SatelliteSubstitute httpwwwaerovironmentcom

Resources

AJ Appleby and FR Foulkes FuelCell Handbook Van NorstandReinhold New York 1989

SR Narayanan G Halpert etalThe Status of Direct MethanolFuel Cells at the Jet PropulsionLaboratory Proceedings of the37th Annual Power SourceSymposium Cherry Hill NJJune 17 1996

Department of Defense Fuel CellDemonstration Programhttpdodfuelcellscom

Energy EfficiencyRenewable EnergyNetwork httpwwwerendoegov

Hydrogen amp Fuel Cell Letterhttpmhvnet~hfcletter

Hydrogen and the Materials of aSustainable Energy FuturehttpeducationlanlgovRESOURCESh2

Karl Kordesh and Gunter SinanderFuel Cells and Their ApplicationsVCH Publishers New York 1996

DOE Office of TransportationTechnologies httpwwwottdoegov

United States Council For AutomotiveResearch httpwwwuscarorg

Arthur D Littlehttpwwwarthurdlittlecom

17

Electrochemistry of a Direct Methanol Fuel Cell

T he electrochemical reactions occurringin a direct methanol fuel cell are

Anode CH3OH + H2O CO2 + 6H+ + 6e-

Cathode 32 O2 + 6H+ + 6e- 3H2O

Cell reaction CH3OH + 32 O2 CO2 + 2H2O

Mixing TankMeOH + H2O

Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k

Emissions from Fuel Cell Engines

The potential of fuel cells to provide zero or near zeroemissions has been a significant force in the developmentof the technology over the past 30 years Direct hydro-genair systems (utilizing on-board hydrogen storage)are the only fuel cells having zero emissions from thetailpipe On-board processing of gasoline methanol andother carbon-based fuels into hydrogen rich gas can bedone with minute amounts of tailpipe emissions andwater and CO2 as the major by-products Over the nextfew years near-zero emissions and performance willcontinue to improve

Schematic of direct methanol fuel cell system(Courtesy Los Alamos National Laboratory)

The Opel Zafira by General Motors reforms methanol to operatea polymer electrolyte membrane fuel cell This vehicle has nearlyzero emissions of sulfur dioxide and nitrogen oxides and the carbondioxide output is expected to be 50 less than a comparableinternal combustion engine vehicle (Courtesy General Motors)

Direct Methanol Fuel Cell

As its name implies methanol fuel is directly used in this fuel cell In thedirect methanol fuel cell as in the hydrogenair fuel cell oxygen from thesurrounding air is the oxidant however there is no oxidation of hydrogenLiquid methanol is the fuel being oxidized directly at the anode

Direct methanol fuel cell technology unique as a lowtemperature fuel cell system not utilizing hydrogen isstill relatively new compared to hydrogenair polymerelectrolyte fuel cell technology with several challengesremaining Recent advances in direct methanol fuel cellresearch and development have been substantial withthe direct methanol fuel cell achieving a significantfraction of the performance of direct hydrogenair fuelcells However there are critical obstacles to be over-come To achieve high current the necessary amount ofexpensive platinum catalyst is still much greater than theamount used in hydrogenair polymer electrolyte fuelcells Methanol fuel crosses through the membrane fromthe anode to the cathode this undesired methanolldquocrossoverrdquo decreases the performance of the air cathodeand wastes fuel

The advantages of supplying methanol directly to thefuel cell are significant mdash with consumer acceptance of aliquid fuel being high on the list While a new ormodified infrastructure would be required to supplylarge quantities of methanol there are some methanolpumps already available Importantly a direct methanolfuel cell system does not require a bulky and heavyhydrogen storage system or a reforming subsystemThis advantage in terms of simplicity and cost meansthe direct methanol fuel cell system presents an attrac-tive alternative to hydrogen or reformate-fed systems Inaddition a direct methanol fuel cell is considered a zeroemission vehicle

Renewable regenerative fuel cell utilizing the energy source of the sunto produce power (Courtesy Aerovironment)

In the near term fuelavailability could bean important reason

for operating fuel cellvehicles on gasolineToday oil refiners in

the US are spendingover $10 billionto comply with

reformulated gasolineregulations to help

lower tailpipeemissions Fuel cell

vehicles operating onalternative fuels

will require new andexpensive fueling

infrastructuresHowever

alternative fuels willprovide superior

environmentalperformance In the

long term incrementalinvestments in a new

domestic fuelinfrastructure will be

necessary for the21st century

RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen

CNG CompressedNatural Gas

Regenerative Fuel Cell

A regenerative fuel cell currently being developed for utility applications uses hydrogen andoxygen or air to produce electricity water and waste heat as a conventional fuel cell doesHowever the regenerative fuel cell also performs the reverse of the fuel cell reaction usingelectricity and water to form hydrogen and oxygen In the reverse mode of the regenerativefuel cell known as electrolysis electricity is applied to the electrodes of the cell to force thedissociation of water into its components

The ldquoclosedrdquo system of a regenerative fuel cell could have a significant advantage because itcould enable the operation of a fuel cell power system without requiring a new hydrogeninfrastructure There are two concerns to be addressed in the development of regenerativefuel cells The first is the extra cost that would be incurred in making the fuel cell reversible

Unmanned solar plane powered by a renewable regenerativefuel cell (Courtesy Aerovironment)

The second drawback to theoperation of the regenerativefuel cell is the use of gridelectricity to produce thehydrogen In the United Statesmost electricity comes fromburning fossil fuels The fossilfuel electricity hydrogenenergy route generates signifi-cantly more greenhouse gasesthan simply burning gasoline inan internal combustion engineAlthough the concept of aregenerative fuel cell is attrac-tive until renewable electricityeg electricity from solar orwind sources is readilyavailable this technologywill not reduce greenhousegas emissions

19

Characteristics of Potential Fuel Cell Fuels

Production

RFG

M 100

E 100

H2

CNG

StorageCost est

gal eq SafetyDistribution

InfrastructureEnvironmental

Attributes

Large existing production operation

Uses imported feedstock

No energy security or trade balance benefits

Conventional storage tanks

Low flashpoint

Narrow flammability limits

Potentially carcinogenic when inhaled

Existing infrastructure and distribution system

Reduction in greenhouse gases

Much lower reactive hydrocarbon and sulfur oxide emissions than gasoline

Abundant domesticimported natural gas feedstock

Can be manufactured renewably from domestic biomass - not currently being done

Requires special storage because fuel can be corrosive to rubber plastic and some metals

Toxic and can be absorbed through the skin

No visible flame

Adequate training required to operate safely

Infrastructure needs to be expanded

High greenhouse gas emissions when manufactured from coal

Zero emissions when made renewably

Made from domestic renewable resources corn wood rice straw waste switchgrass Many technologies still experimental

Production from feedstocks are energy intensive


Wide flammability limit


Less toxic than methanol and gasoline

Nearly no infrastructure currently available

Foodfuel competition at high productions levels

Zero carbon dioxide emissions as a fuel

Significant emissions in production

Domestic manufacturing

Steam reforming of coal natural gas or methane

Renewable solar

Compressed gas cylinders

Cryogenic fuel tanks

Metal hydrides

Carbon nanofibers

Currently storage systems are heavy and bulky

Low flammability limit

Disperses quickly when released

Nearly invisible flame

Odorless and colorless

Non-toxic


Needs new infrastructure

High emissions when manufactured from electrolysis

Lower emissions from natural gas

Zero emissions when manufactured renewably

$05-15 more than gasoline

$110-$115

$79-$191

Abundant domesticimported feedstock

Can be made from coal

CNG needs to be compressed during refueling and requires special nozzles to avoid evaporative emissions

Stored in compressed gas cylinders

Low flashpoint

Non-carcinogenic

Dissipates into the air in open areas

High thermal efficiency


Limitedinfrastructure

Non-renewable

Possible increase in nitrogen oxide emissions

$85

$90

US Congress Office of Technology Assessment ldquoReplacing Gasoline-Alternative Fuels for Light-Duty Vehiclesrdquo OTA-E-364 September 1990Union of Concerned Scientists Summary of Alternative Fuels 1991US Department of Energy Taking an Alternative Route 1994National Alternative Fuel and Clean Cities Hotline httpwwwafdcdoegovJason Mark ldquoEnvironmental and Infrastructure Trade-Offs of Fuel Choices for Fuel Cell Vehiclesrdquo Future Transportation Technology Conference San Diego CA August 6-8 1997 SAE Technical Paper 972693

19

A laptop computer using a fuel cell power source can operate for up to 20 hourson a single charge of fuel (Courtesy Ballard Power Systems)

References

Natural Gas Fuel Cells FederalTechnology Alert Federal EnergyManagement Program USDepartment of EnergyNovember 1995

JL Preston JC Trocciola and RJSpiegel ldquoUtilization and Control ofLandfill Methane by Fuel Cellsrdquopresented at US EPA GreenhouseGas Emissions amp MitigationResearch Symposium June 27-291995 Washington DC

GD Rambach and JD Snyder AnExamination of the CriteriaNecessary for Successful WorldwideDeployment of Isolated RenewableHydrogen Stationary PowerSystems XII World HydrogenEnergy Conference Buenos AiresJune 1998

Keith Kozloff ldquoPower to ChooserdquoFrontiers of Sustainability WorldResources Institute Island Press1997

Resources

Federal Energy Technology Centerhttpwwwfetcdoegov

World Fuel Cell Councilhttpmembersaolcomfuelcells

Michael Corbett Opportunities inAdvanced Fuel Cell TechnologiesVolume One Stationary PowerGeneration 1998 ndash 2009 Kline ampCo Inc Fairfield NJ August1998

Definitions

Quad A unit of heat energy equal to1015 British thermal units

The worlds first prototype polymer electrolyte membrane fuel cell (on theright) used to provide all residential power needs for a home in Latham New York This 7kW unit is attached to a power conditionerstorage unit that stores excess electricity (Courtesy Plug Power)

21

4 Times Square in New York City is one of thefirst office buildings in the US to be poweredby a 200 kW phosphoric acid fuel cell system(Courtesy International Fuel Cells)

Fuel cells are becoming analternative choice for ruralenergy needs

bull In places where there are noexisting power grids

bull Where power supply is oftenunreliable

bull In remote locations that arenot accessible to power lines

F uel cells were developed for and have long been used in the space programto provide electricity and drinking water for the astronauts Terrestrial

applications can be classified into categories of transportation stationary orportable power uses

Polymer electrolyte membrane fuel cells are well suited to transportationapplications because they provide a continuous electrical energy supply fromfuel at high levels of efficiency and power density They also offer theadvantage of minimal maintenance because there are no moving parts in thepower generating stacks of the fuel cell system

The utility sector is expected to be an early arena where fuel cells will bewidely commercialized Today only about one-third of the energy con-sumed reaches the actual user because of the low energy conversionefficiencies of power plants In fact fossil and nuclear plants in the US vent21 quads of heat into the atmosphere mdash more heat than all the homes andcommercial buildings in the country use in one year Using fuel cells forutility applications can improve energy efficiency by as much as 60 whilereducing environmental emissions Phosphoric acid fuel cells have beengenerally used in the initial commercialization of stationary fuel cell systemsThese environmentally friendly systems are simple reliable and quiet Theyrequire minimal servicing and attention Natural gas is the primary fuelhowever other fuels can be used mdash including gas from local landfills pro-pane or fuels with high methane content All such fuels are reformed tohydrogen-rich gas mixtures before feeding to the fuel cell stack Over 200(phosphoric acid fuel cells) units 200 kilowatts each are currently in opera-tion around the world Fuel cell manufacturers are now developing smallscale polymer electrolyte fuel cell technology for individual home utility andheating applications at the power level of 2-5 kilowatts because the potentialfor lower materials and manufacturing costs could make these systemscommercially viable Like the larger fuel cell utility plants smaller systemswill also be connected directly to natural gas pipe lines mdash not the utility gridIn addition to these small scale uses polymer electrolyte fuel cell technologyis also being developed for large scale building applications

ldquoDistributed powerrdquo is a new approach utility companies are beginning toimplement mdash locating small energy-saving power generators closer to wherethe need is Because fuel cells are modular in design and highly efficientthese small units can be placed on-site Installation is less of a financial riskfor utility planners and modules can be added as demand increases Utilitysystems are currently being designed to use regenerative fuel cell technologyand renewable sources of electricity

PotentialApplicationsfor Fuel Cells

Comparison of Five Fuel Cell Technologies

T he electrolyte defines the key properties particularly operating tempera-ture of the fuel cell For this reason fuel cell technologies are named by

their electrolyte Four other distinct types of fuel cells have been developedin addition to the polymer electrolyte membrane fuel cell

bull alkaline fuel cellsbull phosphoric acid fuel cellsbull molten carbonate fuel cellsbull solid oxide fuel cells

These fuel cells operate at different temperatures and each is best suited toparticular applications The main features of the five types of fuel cells aresummarized in chart form

Other Fuel Cell Technologies

Fuel Cell

Polymer ElectrolyteMembrane (PEM)

Alkaline (AFC)

Phosphoric Acid (PAFC)

Molten Carbonate (MCFC)

Solid Oxide (SOFC)

Electrolyte

Solid organicpolymerpoly-perfluorosulfonicacid

Aqueous solution ofpotassium hydroxidesoaked in a matrix

Liquid phosphoricacid soaked in amatrix

Liquid solution oflithium sodium andor potassium carbon-ates soaked in amatrix

Solid zirconium oxideto which a smallamount of ytrria isadded

OperatingTemperature (degC)

60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000

ElectrochemicalReactions

Anode H2 2H+ + 2e-

Cathode 12 O2 + 2H+ + 2e- H2O

Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-

Cathode 12 O2 + H2O + 2e- 2(OH)-

Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + CO32- H2O + CO2 + 2e-

Cathode 12 O2 + CO2 + 2e- CO32-

Cell H2 + 12 O2 + CO2 H2O + CO2

(CO2 is consumed at cathode and produced at anode)

Anode H2 + O2- H2O + 2e-

Cathode 12 O2 + 2e- O2 -

Cell H2 + 12 O2 H2O

23

Applications

electric utilityportable powertransportation

militaryspace

electric utilitytransportation

electric utility

electric utility

Advantages

bull Solid electrolyte reducescorrosion amp management problems

bull Low temperaturebull Quick start-up

bull Cathode reaction faster in alkalineelectrolyte mdash so high performance

bull Up to 85 efficiency in co-generation of electricity

and heatbull Impure H2 as fuel

bull High temperature advantages

bull High temperature advantagesbull Solid electrolyte advantages

(see PEM)

Disadvantages

bull Low temperature requiresexpensive catalysts

bull High sensitivity to fuel impurities

bull Expensive removal of CO2 from fueland air streams required

bull Pt catalystbull Low current and powerbull Large sizeweight

bull High temperature enhancescorrosion and breakdown of cellcomponents

bull High temperature enhancesbreakdown of cell components

High temperature advantages include higher efficiency and the flexibility to use more types of fuels and inexpensive catalysts as thereactions involving breaking of carbon to carbon bonds in larger hydrocarbon fuels occur much faster as the temperature is increased

23

C=Carbon H=Hydrogen

Trends in energy use Hydrogen-to-Carbonratio increases as we become less dependenton carbon-based fuels(Courtesy ldquoWiredrdquo 1097)

H ydrogen is the most attractive fuel for fuel cells mdash having excellentelectrochemical reactivity providing adequate levels of power density

in a hydrogen air system for automobile propulsion as well as having zeroemissions characteristics

Historically the trend in energy use indicates a slow transition from fuelswith high carbon content beginning with wood to fuels with more hydro-gen Fossil fuels release varying quantities of carbon dioxide into theatmosphere mdash coal having the highest carbon content then petroleum andfinally natural gas mdash the lowest carbon dioxide emitter per thermal unitHydrogen obviously releases no carbon dioxide emissions when burned

Hydrogen (H2) is the most abundant element in the universe althoughpractically all of it is found in combination with other elements for ex-ample water (H2O) or fossil fuels such as natural gas (CH4) Thereforehydrogen must be manufactured from either fossil fuels or water before itcan be used as a fuel Today approximately 95 of all hydrogen is producedby ldquosteam reformingrdquo of natural gas the most energy-efficient large-scalemethod of production Carbon dioxide (CO2) is a by-product of thisreaction

CH4 + 2H2O 4H2 + CO2

Hydrogen can also be produced by gasification of carbon containing materi-als such as coal mdash although this method also produces large amounts ofcarbon dioxide as a by-product Electrolysis of water generates hydrogenand oxygen

H2O H2 + 12O2

The electricity required to electrolyze the water could be generated fromeither fossil fuel combustion or from renewable sources such as hydro-power solar energy or wind energy In the longer term hydrogengeneration could be based on photobiological or photochemical methods

While there is an existing manufacturing distribution and storage infrastruc-ture of hydrogen it is limited An expanded system would be required ifhydrogen fuel were to be used for automotive and utility applications

In 1809 an amateur inventorsubmitted a patent for this hydrogen car

Hydrogen As a FuelWood Coal OilNatural

Gas Hydrogen

C

H

25

While a single hydrogen productiondistributionstorage system may not be appropriate for the diverseapplications of fuel cells it is certainly possible that acombination of technologies could be employed to meetfuture needs All of the system components are cur-rently available mdash but cost effective delivery anddispensing of hydrogen fuel is essential If hydrogenwere to become available and affordable this wouldreduce the complexity and cost of fuel cell vehicles mdashenhancing the success of the technology

ldquoHydrogen Economyrdquo is an energy system based uponhydrogen for energy storage distribution and utiliza-tion The term coined at General Motors in 1970caught the imagination of the popular press During theoil crisis in the early 70rsquos the price of crude oil sharplyincreased concern over stability of petroleum reservesand the potential lack of a secure energy source grewand government and industry together developed plansand implementation strategies for the introduction ofhydrogen into a world energy system However thelessening of tensions in the Middle East led to a loweringof crude oil prices and the resumption of business asusual Petroleum has continued to be the fuel of choicefor the transportation sector worldwide

Hydrogen fuel has the reputation of being unsafeHowever all fuels are inherently dangerous mdash howmuch thought do you give to the potential dangers ofgasoline when you drive your car Proper engineeringeducation and common sense reduce the risk in anypotentially explosive situation A hydrogen vehicle andsupporting infrastructure can be engineered to be as safeas existing gasoline systems Dealing with the perceptionand reality of safety will be critical to the successful wideintroduction of hydrogen into our energy economy

References

Peter Hoffmann ldquoThe Forever FuelThe Story of Hydrogen BoulderWestview Pressrdquo 1981

James Cannon ldquoHarnessingHydrogen The Key toSustainable TransportationrdquoNew York Inform 1995

rdquoStrategic Planning for the HydrogenEconomy The HydrogenCommercialization PlanrdquoNational Hydrogen AssociationNovember 1996

US Department of EnergyHydrogen Program PlanFY 1993 - FY 1997

Richard G Van Treuren ldquoOdorlessColorless BlamelessrdquoAir amp Space May 1997

National Hydrogen Associationhttpwwwttcorpcomnhaadvocatead22zepphtm

Resources

HyWeb httpwwwHyWebdeHydrogen InfoNet

httpwwwerendoegovhydrogeninfonethtml

The New Sunshine Programhttpwwwaistgojpnsstextwenethtm

CE Thomas Hydrogen VehicleSafety Report NationalTechnical Information ServiceUS Department of CommerceSpringfield Virginia July 1997

ldquoShell has established a Hydrogen Economy team dedicatedto investigate opportunities in hydrogen manufacturing and

new fuel cell technologiesrdquo

Chris Fay Chief Executive Shell UK

25

Front page of The New York Times May 7 1937 the day after the explosionof the Hindenberg (Enhanced color photograph courtesy National Hydrogen Association)

ldquoDonrsquot paint your ship with rocket fuelrdquoAt 730 on the evening of May 6 1937 the Hindenburg dirigible was destroyed by fire and explosions as it was about to land inLakehurst New Jersey 62 passengers survived and 35 lost their lives The Hindenburg was nearing its landing site during anelectric storm According to observers on the ground the dirigible began to drift past its landing position and after a brief delaythe ship started to valve hydrogen into what was highly charged outside air This combination of factors could prompt severecorona activity on any airship In fact an eyewitness reported seeing a blue glow of electrical activity atop the ill-fated Hindenburgbefore the fire started which is indicative of the extremely high temperatures typical of a corona discharge As the crewattempted to bring it back on course the ship lost its balance the tail touched the ground and the stern burst into flames Passen-gers who were afraid the ship might explode jumped to their deaths The burns and other injuries were a result of the diesel fuel

fire not from hydrogen Most of thepassengers who waited for the airship toland walked safely away from the acci-dent

Until recently this tragedy was thoughtto be caused by hydrogen the highlyflammable gas used to inflate the skin ofthe ship However historical photo-graphs show red-hot flames andhydrogen burns invisibly Also no onesmelled garlic the scent which had beenadded to the hydrogen to help detect aleak The mystery of the Hindenburgwas solved by Addison Bain a formermanager of the hydrogen programs forNASA Using infrared spectrographs anda scanning electron microscope Bainworking with other NASA scientists wasable to discover the chemical makeup ofthe organic compounds and elementspresent in the fabric of the dirigiblersquosskin The Hindenburg was covered with acotton fabric that had been treated with adoping compound to protect andstrengthen it mdash however this compoundcontained a cellulose acetate or nitrate(gunpowder) Aluminum powder (whichis used in rocket fuel) was also identifiedThe outside structure was wooden andthe inside skeleton was duralumin coatedwith lacquer The combination was flam-mable and deadly

27

T he success story of the past three decades in the transportation sector hasbeen the dramatic reduction of air-polluting emissions from new ve-

hicles Emission rates of gasoline vehicles have fallen by 70 ndash 90 and thecosts for cleaner cars have also fallen Under real driving conditions actualreductions are about 70 for nitrogen oxides and 90 for hydrocarbon andcarbon monoxide emissions With a near zero emission gasoline car on thehorizon and legislation in California and the Northeast states mandating10 of the new vehicle market to be zero emission vehicles by 2003 evengreater reductions in emissions are imminent These are important improve-ments in the US mdash but still one in four Americans breathes unhealthy airItrsquos worse in the rest of the world Cities such as Mexico City Athens andShanghai donrsquot have the same stringent emissions standards found at home mdashand transportation remains the largest contributor to urban pollutionWorldwide over one billion people living in urban areas are suffering fromsevere air pollution and according to the World Bank over 700000 deathsresult each year

Estimates from the EPA indicatethat motor vehicles in the US still account for

bull 78 of all Carbon Monoxide emissionsbull 45 of Nitrogen Oxide emissionsbull 37 of Volatile Organic Compounds

The impact of lower emission gasoline vehicles is being offset by the growthin the number and size of vehicles on the road as well as an increase in thenumber of miles each vehicle travels Americans pay around $36 per gallonin fuel tax as opposed to our European counterparts who spend an average of$250 per gallon in taxes Low gasoline prices donrsquot encourage fuel efficiencyor conservation Rather the sport utility vehicle market share continues torise now surpassing passenger vehicles Even as these larger vehicles havecleaner tailpipe emissions energy use and carbon dioxide emissions willcontinue to increase If recent growth trends continue Americans will bedriving twice as many miles in 2015 as we do today Along with continuingresearch on cleaner transportation options it will be critical to developpolicies that decrease the number of cars on the road minimize congestionencourage public transportation as well as telecommuting

The remarkable developmentsof fuel-cell engines will helpCalifornia in its war on smog aswell as provide new consumerschoices for transportation

California Air Resources Board August 1998

The Evolution ofthe Zero EmissionVehicle (in the 1990rsquos)

The 1990 Clean Air Act Amendments along withthe National Energy Policy Act of 1992 pavedthe way for less polluting gasoline vehicles andthe introduction of alternative fuel vehicles onthe roads in the US Also in 1990 the Califor-nia Air Resources Board recognized that eventhe cleanest gasoline powered vehicles wouldnrsquotreduce pollution enough to satisfy the statersquosgoals for healthful air Meeting state and fed-eral air standards in seriously polluted areassuch as Los Angeles would require either restric-tions on driving or a large-scale switch tovehicles that donrsquot pollute California adoptedthe Low Emission Vehicle Act that mandated theseven largest auto manufacturers begin immedi-ately to reduce all tailpipe emissions and tointroduce zero emission vehicles (ZEVs) by1998

In March 1996 the California Air ResourcesBoard modified their zero emission vehicle pro-gram to encourage a market based introductionin the near-term and to promote future ad-vances in electric vehicle (including fuel cells)technology Beginning in 2003 10 of thenew vehicles will be required to be zero emis-sion vehicles or nearly zero emission vehiclesmdash also knows as equivalent ZEVs

Because of the legislative initiative taken byCalifornia and subsequent similar regulationsimposed by a number of states in the North-east every major automobile manufacturer hasmade significant progress toward the develop-ment of ultra-low and zero emission vehicles

Getting To CleanerTransportation

1930 rsquo40 rsquo50 rsquo60 rsquo70 rsquo80 rsquo90 2000 rsquo10 rsquo20 rsquo30 rsquo40 rsquo50

Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25

30WorldWorld projectedWorld outside Persian GulfWorld outside projected

35

30

25

2015

10

0501950 rsquo60 rsquo70 rsquo80 rsquo90 2000

Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year

N o one can predict what willhappen to world wide oil prices

or global oil demand The worldrsquosproduction of oil reached a recordlevel of 65 million barrels a day in1997 and global demand is risingmore than 2 a year Americansspend roughly $100000 per minuteto purchase foreign oil and the UStransportation sector uses over 10of the worldrsquos oil Consumption ofoil by passenger vehicles whichinclude automobiles and light dutytrucks exceeds all of the UnitedStatesrsquo domestic production Re-serves of fossil fuels are large butfinite and there is growing evidenceto suggest that world production ofcrude oil will peak early in the 21st

century The Energy InformationAgency forecasts that worldwidedemand for oil will increase 60 by2020 By 2010 Middle East OPECstates (Organization of PetroleumExporting Countries) considered to

US oil production in the lower 48 states (upper right) peaked in 1970 aspredicted by a bell shaped curve World oil production is expected to follow suit(Courtesy Science vol 281 Aug 211998 p1128 C Campbell amp J Laher re re)

Oil ReservesTransportationand Fuel Cells

be unpredictable and often unstablewill have over 50 of the world oilbusiness and the switch fromgrowth to decline in oil productioncould cause economic and politicaltension As excess oil productioncapacity begins to decline over thecoming decades oil prices can beexpected to rise and the transporta-tion sector is likely to be mostheavily affected by these fluctua-tions World wide transportationrelies almost totally on oil and thereare few viable short-term fueloptions

Every gallon of gasolinemanufactured distributed and

then consumed in a vehiclereleases roughly 25 pounds

of carbon dioxide

About 25 of all human-generatedgreenhouse gases come from trans-portation mdash more than half of thatfrom light-duty vehicles Unlike airpollutants (carbon monoxidenitrogen oxides hydrocarbons andparticulates mdash soot smoke etc)greenhouse gas emissions (primarilycarbon dioxide methane nitrousoxide water vapor etc) fromvehicles cannot be easily or inexpen-sively reduced by using add-oncontrol devices such as a catalyticconverter In addition unlike airpollutants greenhouse gas emissionsare not regulated by the Environ-mental Protection Agency Therelationship between gasolineconsumption and carbon dioxideemissions is fixed Today increasingfuel economy reducing vehicle milestraveled and switching to lower ornon-carbon fuels will begin todecrease carbon dioxide emissions

The introduction of fuel cells intothe transportation sector willincrease fuel efficiency decreaseforeign oil dependency and becomean important strategytechnology tomitigate climate change As fuel cellvehicles begin to operate on fuelsfrom natural gas or gasoline green-house gas emissions will be reducedby 50 In the future the combina-tion of high efficiency fuel cells andfuels from renewable energy sourceswould nearly eliminate greenhousegas emissions The early transition tolower carbon-based fuels will beginto create cleaner air and a strongernational energy security

Since 1985 energy use is upbull 40 in Latin Americabull 40 In Africabull 50 in Asia

29

T here is a growing scientific consensus that increasinglevels of greenhouse gas emissions are changing the

earthrsquos climate The natural greenhouse gases includecarbon dioxide (CO2) water vapor (H2O) nitrous oxide(N2O) methane (CH4) and ozone (O3) and are essentialif the Earth is to support life With the exception ofwater vapor carbon dioxide is the most plentiful Sincethe beginning of the Industrial Revolution in 1765burning fossil fuels and the increased energy needs of agrowing world population have added man-made oranthropogenic greenhouse gas emissions into theenvironment Carbon dioxide constitutes a tiny fractionof the earthrsquos atmosphere mdash about one molecule in threethousand mdash but is the single largest waste product ofmodern industrial society The concentration of carbondioxide in the atmosphere has risen from about 280 partsper million by volume to the current level of over 360parts per million by volume and anthropogenicallycaused atmospheric concentration of methane hasdoubled In the past 100 years levels of nitrous oxidehave risen about 15 Increasing concentrations ofgreenhouse gases trap more terrestrial radiation in thelower atmosphere (troposphere) artificially enhancingthe natural greenhouse effect The average temperatureof the Earth has warmed about 1degC since the mid-19thcentury when measurements began and fragmentaryrecords suggest the Earth is warmer than it has been innearly 2000 years

ldquoThe balance of evidence suggests that thereis a discernible human influence on global

climaterdquo

United Nations Intergovernmental Panel on Climate Change 1995

Under the most optimistic scenarios proposed by theUnited Nations Intergovernmental Panel on ClimateChange carbon dioxide is expected to rise to approxi-mately 600 parts per million by volume during the nextcentury mdash more than double the level held for 10000years since the end of the last ice age

Climate ChangeGreenhouse Gases and Fuel

Cells What is the Link

The CO2 level has increased sharply since the beginning of theIndustrial Era and is already outside the bounds of natural variabilityseen in the climate record of the last 160000 years Continuation ofcurrent levels of emissions are predicted to raise concentrations toover 600 ppm by 2100 (Courtesy Office of Science and TechnologyPo l i cy)

Based on these scenarios the Intergovernmental Panel on Climate Changehas concluded that the increase in greenhouse gases may be expected tocause a rise in the global average temperature of between 1degC and 35degC inthe 21st century

In 1997 global carbon emissions amounted to more than six billiontons mdash more than a ton for every human being on the planet

1998 was the warmest year on record and no one is absolutely certain whatthese temperature increases will do mdash changes in precipitation extremeweather and sea level rise are all possible The climate modeling andresulting scientific conclusions are not universally accepted because climatecodes have difficulties simulating such events The picture is far from clearbut it appears that climate is driven by a variety of forcing mechanisms mdashand anthropogenic forcing must be placed within the total context thatincludes the long-term variations of the earthrsquos orbit solar variability andthe natural cycles of nature However as all of these data are taken intoaccount evidence is increasing that the climate model predictions cannot betoo far wrong and that we are warming the Earth Compelling societalimplications place even more significance on prudent policy directions

References

Jason Mark ldquoZeroing out PollutionThe Promise of Fuel CellsrdquoUnion of Concerned Scientists1996

Daniel Sperling ldquoA New AgendardquoACCESS Number 11 Universityof California TransportationCenter Fall 1997

Reinhold Wurster ldquoPEM Fuel Cellsin Stationary and Mobile Appli-cationsrdquo Electric and LightingIndustry Biennial Buenos AriesSeptember 1997

W Wayt Gibbs ldquoTransportationrsquosPerennial Problemsrdquo ScientificAmerican Oct 1977

Toward a Sustainable FutureldquoAddressing the Long-TermEffects of Motor VehicleTransportation on Climate andEcologyrdquo TransportationResearch Board NationalResearch Council NationalAcademy Press 1997

James J MacKenzie ldquoDriving theRoad to Sustainable GroundTransportationrdquo WorldResources Institute ldquoFrontiersof SustainabilityEnvironmentally SoundAgriculture ForestryTransportation and PowerProductionrdquo Island Press1997

ldquoCars and Trucks and GlobalWarmingrdquo Union of ConcernedScientists ND

M Kerr ldquoThe Next Oil Crisis LoomsLarge mdash and Perhaps CloserdquoScience August 21 1998

Resources

Presidentrsquos Council on SustainableDevelopment httpwwwwhitehousegovPCSD

Rocky Mountain Institute httpwwwrmiorg

California Air Resources Boardhttpwwwarbcagovhomepagehtm

InstrumentalTemperature Recordfrom 1860 ndash 1999indicates a globalwarming over thepast century withmany peaks and val-leys suggesting thenatural year-to-yearvariability of climate(Courtesy HadleyCentre for ClimateP red i c t i onamp Research)

The Science of Global Climate Change

The regulating factor for global climate change depends on a fundamental principle theFirst Law of Thermodynamics also known as the Law of Conservation of Energy

Mathematically this can be represented as follows

dQ = dU ndash dW

where dQ = heat added to the system dU = change in the internal energy of the system anddW = work extracted Energy cannot be gained or lost in a stable system it can only changeforms Such a system is said to follow an ldquoEnergy Balance Modelrdquo To maintain stabilitythe Earth-ocean-atmosphere system absorbs energy from the Sun radiates it in the form ofinfrared (heat) energy and transports it in the form of both latent heat and sensible heatflux Several natural events (volcanic eruptions forest fires fluctuating intensity of solarradiation varying cloud cover and others) and human activities (fuel combustion aerosolproduction and industrial and land use practices that release or remove heat-trappinggreenhouse gases and others) can affect the balance between absorption and emissionof radiation

1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000

Global surface temperatures 1860 - 1999

Chan

ge in

temp

erat

ure (

degr

ees C

)

31

While the link between climateand ecology remains uncertaindecisions made during thenext ten years could affectgenerations to come

The Climate Change Debate

The Road to Kyoto How the Global Climate Treaty Fosters Economic Impoverishment and Endangers US Security Angela Antonelli etalThe Heritage Foundation Roe Backgrounder No1143 October 6 1997

The Forgiving Air ndash Understanding Environmental Change Richard CJ Sommerville University of California Press 1996

Global Warming The High Cost of the Kyoto Protocol ndash National and State Implications WEFA Inc 1998

Kyoto Protocol A Useless Appendage to an Irrelevant Treaty Testimony of Patrick Michaels Cato Institute Committee on Small BusinessUS House of Representatives July 29 1998

CLIMATE Making Sense and Making Money Amory B Lovins and LHunter Lovins Rocky Mountain Institute November 13 1997

The Costs of Climate Protection A Guide for the Perplexed Robert Repetto and Duncan Austin World Resources Institute 1997

The Greenhouse Effect Essentially all energy that enters the Earthrsquos atmospherecomes from the sun The incoming radiation is partly absorbed partly scattered and partlyreflected back into space by the various gases of the atmosphere clouds and aerosols mdash tinyparticles suspended in the atmosphere The sun emits solar radiation mainly in the form of vis-ible and ultraviolet radiation As this radiation travels toward Earth approximately 25 of itis absorbed by the atmosphere and 25 is reflected by the clouds back into space The re-maining radiation travels to the Earth and heats its surface Because the Earth is much coolerthan the sun energy reflected from the Earthrsquos surface is lower in intensity than that emittedfrom the sun ie in the form of invisible infrared radiation About 90 of the infrared radia-tion reflected by the earthrsquos surface is absorbed by atmospheric trace gases also known asldquogreenhouse gasesrdquo before it can escape to space These gases as well as clouds re-emitthis radiation mdash sending it back toward ground The atmosphere acts like the glass in a green-house allowing short-wavelength radiation to travel through but trapping some of the longwavelength infrared radiation which is trying to escape This process makes the temperatureof the atmosphere rise just as it does in the greenhouse This is the Earthrsquos natural greenhouseeffect and keeps our planet about 60ordmF warmer than it might otherwise be(Courtesy National Oceanic and Atmospheric Administration)

While the link between climate andecology remains uncertain decisionsmade during the next ten years couldaffect generations to come Giventhe current levels of uncertainty thecomplexity of our environment andthe potential for ldquosurprisesrdquo orunanticipated events prudent actionappears to win out over a ldquobusinessas usualrdquo scenario Given the longtime lags between cause and effectand between effect and remedy weare challenged to use technologywisely to enhance our investment inthe future The worldrsquos governmentshave signed a climate convention andare negotiating implementationstrategies It is not unreasonable tosuggest that the introduction of fuelcells into the transportation andenergy sectors will have globalimplications Energy efficiencyreducing world use of petroleum thetransition to renewable fuels andcontinued support for research areimportant and responsible steps

S ustainable development is one of those often usedbut seldom defined phrases According to the

United Nations it is ldquomeeting the needs of the presentwithout compromising the ability of future generationsto meet their own needsrdquo Attaining sustainable devel-opment doesnrsquot mean that growth must stop it doesmean that environmental limits do exist because of thelimited ability of the biosphere to deal with the wastesfrom human activities This is one of the greatestchallenges we face today mdash a challenge that can only bemet by responsibly developing and using technologiesthat will protect our environment for everyone

Todayrsquos innovations in fuel cell technology are address-ing local national and global environmental needs Thedecision to become involved with bringing these innova-tions into our daily lives is a strategic career opportunityand a smart thing to do The winners will be thosepeople who are ahead of the crowd

Innovative solutions can be an important competitiveplus Over half of the threat to our climate disappears ifwe use energy in ways that save money In general itrsquosfar cheaper to be efficient and save fuel than burn fuelFuel cells offer an opportunity for innovation Helpingto make fuel cells be a part of the solution might be achallenge thatrsquos too exciting to ignore

ldquoDeveloping countries face a fundamental choice They can mimic the industrialcountries and go through a development phase that is dirty and wasteful and creates anenormous legacy of pollution Or they can leapfrog over some of the steps followed byindustrial countries and incorporate modern efficient technologiesrdquo

ldquoThe Human Development Reportrdquo The United NationsOxford University Press September 1998

A Once-In-A-LifetimeOpportunity

References

ldquoReport to the Nation On OurChanging Planetrdquo NationalOceanic and AtmosphericAdministration Fall 1997

CK Keller ldquoGlobal Warming AnUpdaterdquo httpwwwigpplanlgov

ldquoClimate Change State ofKnowledge rdquo Office of Scienceand Technology Policy 1997

Michael MacCracken and Tom KarlldquoIs the Climate ChangingIndeed It Isrdquo httpwwwusgcrpgovusgcrpmmbralmanachtml

Global Climate Change InformationProgramme httpwwwdocmmuacukaricgccgcciphmhtml

Michael B McElroy A WarmingWorld Harvard MagazineNovember - December 1997

JD Mahlman Uncertainties inProjections of Human-CausedClimate Warming Science278 1997

Michael Porter ldquoTowards a NewConception of the Environment-Competitiveness RelationshiprdquoEnvironmental ProtectionAgency Clean Air MarketplaceWashington DC September1993

Environmental Sciences DivisionCarbon Dioxide Division OakRidge National Laboratoryhttpcdiacesdornlgov

Intergovernmental Panel onClimate Change httpwwwusgcrpgovusgcrpIPCCINFOhtml

T he US Department of Energy through its Office of TransportationTechnologies is pursuing critical technological advances that can help to

create new and improved national transportation systems The Office ofTransportation Technologies supports research that is often too financiallyrisky for private industry to develop on its own Partnerships are developedwith industry working with national laboratories as a way to strengthenresources

The mission of the Office of Transportation Technologiesis to reduce US dependence on petroleum

Within the Office of Transportation Technologies the Office of AdvancedAutomotive Technologies focuses its efforts on developing cleaner and moreenergy-efficient technologies for automobiles of the future The Transporta-tion Fuel Cell Program is just one of many exciting research activities

The Partnership for a New Generation of Vehicles (PNGV) Program is apartnership between 11 government agencies and the United StatesCouncil for Automotive Research a cooperative research effort amongDaimlerChrysler Corporation Ford Motor Company and General MotorsCorporation to develop commercially-viable vehicle technology that overthe long-term can preserve personal mobility reduce the impact of cars andlight trucks on the environment and reduce US dependency on foreign oil

The Alternative Fuels Research and Development Program has beendeveloping alternative fuels technologies in partnership with industry formore than 20 years

The CARAT Program (Cooperative Automotive Research for AdvancedTechnology) supports universities and small businesses to accelerate thedevelopment and production of innovative technologies that address barriersto producing ultra-efficient vehicles including the design and development ofadvanced energy-efficient automotive components and systems

The Graduate Automotive Technology Education Program (GATE) is amultidisciplinary automotive engineering program for graduate students thatfocuses on technologies critical to the development and production of futureautomobiles

Benefits of Office of Transportation Technologies Program

bull Reducing dependence upon foreign oilbull Increasing energy savingsbull Improving air quality by reducing destructive air pollution and

greenhouse gases

To learn more about the Office of Transportation Technologies

wwwottdoegov

Cover

Credits

Whats Inside

A Brief History

The Very Basics and More

Some Comparisons


Other Types of Fuel Cells

What about Fuel

Applications for Fuel Cells

Hydrogen As a Fuel

Getting To Cleaner Transportation

Oil Reserves Transportation and Fuel Cells

Climate Change Greenhouse Gases and Fuel Cells What is the Link

A Once-In-A-Lifetime Opportunity

DOE Office of Transportation Technologies

Backcover

The authors acknowledge the following reviewers

Los Alamos National LaboratoryShimshon GottesfeldCharles F KellerSteffen MOslashller-HolstAntonio Redondo

Office of Advanced Automotive TechnologiesUS Department of Energy

JoAnn Milliken

LA-UR-99-3231

Los Alamos National Laboratory an affirmativeactionequal opportunity employer is operatedby the University of California for the USDepartment of Energy under contract W-7405-ENG-36 All company names logos and productsmentioned herein are trademarks of theirrespective companies Reference to any specificcompany or product is not be construed as anendorsement of said company or product by theRegents of the University of California theUnited States Government the US Department ofEnergy nor any of their employees The LosAlamos National Laboratory strongly supportsacademic freedom and a researcherrsquos right topublish as an institution however theLaboratory does not endorse the viewpoint of apublication or guarantee its technical correctness

1

ndash Green Power

Whatrsquos Inside

2 A Brief History


5 SomeComparisons



19 What About Fuel











The 3M Foundation




A Brief History






3





















The Very Basics







Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

1

ndash Green Power

Whatrsquos Inside

2 A Brief History


5 SomeComparisons



19 What About Fuel











The 3M Foundation




A Brief History






3





















The Very Basics







Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover



A Brief History






3





















The Very Basics







Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

3





















The Very Basics







Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover









The Very Basics







Hydrogen Catalyst

Cathode (+)

Water

Oxygen

Anode (-)

ElectronsProtons

MembraneElectrolyte

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

5












FuelCells Hydrogen

Tank

Mechanical Energy


Turbo-compressor






ElectricMotor

Transaxle

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

References








Resources





















- siteto SO3



- H+


Definitions






1 micron = 10-6 m 10-4 cm 10-3 or0001 mm = 1 m



7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

7









The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

The Electrodes



















9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

9


on carbon particles














9





CarbonPlatinum


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover


Assembly











02mm

AnodeCathode


11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

11

TheBacking Layers






Electrode



Cathodebacking

Anodebacking









Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover







Collectors




Hydrogenflow field


Hydrogenoutlet

Water and air

e -e -

Anodebacking MEA

Cathodebacking


Anodecurrent

collector

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

13









G = H - T S= - 285800 J ndash (298 K)(-1632 JK)= - 237200 J


= - (-237200 J2 x 96487 JV)= 123 V





13

0


Cell V

oltag

e (mV

)

1200

800

600

200

0200 600 800 1000 1400 1600

400

400 1200

1000

l

ll













Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover












Fuel Cell Stack



Hydrogenflow fields

Airflow fields

e- e-

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

15







Fuel Cell Systems









Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover



Cooling pump

Fresh Air

Coolingair out

Coolingair in


Fuel Cells

Compressorexpander

Cooler

Reformerand

catalyticburner

Gas purification

Vaporizer

Methanoltank

Watertank




References







Resources











17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

17







Air exhaust

Air

Air o

utlet

CO2 vented

CondenserFan

Methanol Tank

DMFC

stac

k























RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover















RFG Reformulated

Gasoline

M 100 Methanol

E 100 Ethanol

H2 Hydrogen







19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

19


Production

RFG

M 100

E 100

H2

CNG

StorageCost est



Attributes





Low flashpoint










No visible flame

















Renewable solar



Metal hydrides

Carbon nanofibers






Non-toxic







$110-$115

$79-$191





Low flashpoint

Non-carcinogenic





Non-renewable


$85

$90


19


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover


References





Resources




Definitions



21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

21


















Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover







Fuel Cell


Alkaline (AFC)



Solid Oxide (SOFC)

Electrolyte







60 - 100

90 - 100

175 - 200

600 - 1000

600 - 1000


Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O

Anode H2 + 2(OH)- 2H2O + 2e-


Cell H2 + 12 O2 H2O

Anode H2 2H+ + 2e-


Cell H2 + 12 O2 H2O



Cell H2 + 12 O2 + CO2 H2O + CO2




Cell H2 + 12 O2 H2O

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

23

Applications


militaryspace


electric utility

electric utility

Advantages








(see PEM)

Disadvantages








23

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

C=Carbon H=Hydrogen






CH4 + 2H2O 4H2 + CO2


H2O H2 + 12O2





Gas Hydrogen

C

H

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

25




References







Resources








25





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover





27














Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover


Annu

al oil

prod

uctio

n (bil

lions

of ba

rrels)

0

5

10

15

20

25


35

30

25

2015

10


Billio

ns of

barre

lsye

ar

Lower 48Projected

Year

Year









of carbon dioxide




29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

29




climaterdquo









References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover




References









Resources








dQ = dU ndash dW


1840

100090

080

070

060

050

040

030

020

010

000

-010

-020-030

1860 1880 1900 1920 1940 1960 1980 2000


Chan

ge in

temp

erat

ure (

degr

ees C

)

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

31


















References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover








References





















greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover











greenhouse gases


wwwottdoegov

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

Cover

Credits

Whats Inside

A Brief History


Some Comparisons



What about Fuel


Hydrogen As a Fuel






Backcover

Fuel Cells - Green Power - PDHonline.com · for Fuel Cells 24. Hydrogen as A Fuel 27. Getting To...

Documents

Transcript of Fuel Cells - Green Power - PDHonline.com · for Fuel Cells 24. Hydrogen as A Fuel 27. Getting To...