fuelcells 1.pdf

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Fuel Cells and Hydrogen Energy

System

Week1

2

Humanity's Top Ten Problems for the Next 50Years

1. ENERGY2. WATER

3. FOOD4. ENVRONMENTAL

POLLUTION5. POVERTY6. TERRORISM&WAR7. DISEASE8. EDUCATION9. DEMOCRACY10. POPULATION

2003 6.3 billion humanbeing2050 10 billion humanbeing

Source

3

Energy profile in the world today

Natural gas

Nuclear

HidroelectricityRenewable

Petroleum

Coal

Source

4

5Ballard, February 2003

CO2 emissions for different applications

6

The world s energy demand

Today

Future

6.3 billion

10 billion 15 barrels/population

11 barrels/population

69.3 barrelsof oilequivalent

/year

150 barrelsof oilequivalent/year


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Energy types

Mechanical energy Flowingrivers, wind

Electrical energy

Electromagnetic field, batteries Chemical energy

Released as a result of chemical reaction (Heat,electrochemical/batteries)

Thermal energy Heat (Released as a result of chemical reaction,

nuclear reactions, geothermal sources, etc.)

Usages of different energy sources

Mechanical energy

To operate the devices (heat pumps, machines etc.)

To move the devices

To produce electricity Chemical energy

To produce new chemicals

For heat production

To produce electricity (batteries, fuel cells)

Application areas of different energy sources

Thermalenergy

Heating

For material proceses

Hot water

Electricity production

Electrical energy

The most flexible form of energy

Can be converted to other energies easily

Ease of use and obtain

The most useful is electric energy. Can beconverted to all other energies.

The most commonly available energy isthermal energy. Can be produced by thecombustion of fuels in everwhere.

Chemical energy is the easiest stored energy.Can be converted to electrical and thermalenergies easily.

Energy conversions

Mechanical-mechanical

Water and wind mills

Mechanical-electrical

Generators (motors)

Chemical-electrical

Batteries, fuel cells

Thermal-mechanical

Heat engines, refrigerators

Energy conversions


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13 14

Basic energy sources

Fossil fuels

LIMITED

NOT ENVIRONMENTALLYFRIENDLY

ALTERNATIVE FUELS

SOLUTION

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Non-renewable energy sources

Petroleum

Natural gas

Coal

Nuclear

Renewable energy sources

Solar

Wind

Geothermal

Wave

Biomass

16

Nuclear energy?

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Advantages:

The amount of fuel needed in nuclear power plants is very lowcompared to other systems

Disadvantages:

Radiation from nuclear explosions affects the human healthNuclear waste generationMuch investment is required for security

Nuclear energy?

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Hydroelectricity?


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Advantages:

RenewableCleanConstant power generation can be achieved

Disadvantages:

Dams may adversely affect the surrounding areaDam can destroy the near areaTurbines can kill the fishes

Hydroelectricity?

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Solar energy kWh/m2 year Wo rld : a nn ual

incidentsun:

15.000x

Annual requirementof mankind

Solar energy?

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Solar energy?

Advantages:

Free energy sourceQuiet operationFree of environmental pollutionFast and easy establishmentOperate independentlyLife of system 30-40 yearsMaintanence cost is very low

Disadvantages:

High solar panel costHigh initial investment costNot operating at nights

High area requirements for efficiency22

Wind energy?

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Advantages:

Free energy sourceTo meet the energy requirements of the areas where thenetwork fails

Disadvantages:

CostElectricity production based on the intensity of the windOperate loudlyFine structures can be damaged due to storm

Wind energy?

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Wave energy?


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Wave energy?

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Advantages:

Free energy sourceNo wasteMaintanence and operation is not expensive

Disadvantages:

Dependence to the wavesWave intense area requirementsMay adversely affect marine lifeMay withstand very adverse weather conditions

Wave energy?

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Geothermal?

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Advantages:

No wasteNo fuel requirementSoil is affected in minimum because the cooling water is givenback to the soil

Disadvantages:

The difficulty of finding appropriate areaNot movable easilyHarmfulgases and minerals along with steamOnly drilling to the appropriate rock structures

Geothermal?

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Biomass?

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Advantages:

Agricultural waste can be used for productionIndustrial, agricultural etc wastes canbe reducedEmpty agricultural areas can be used to grow the energy crops

Disadvantages:

The area used to grow energy crops can be necessary forother aims

ExpensiveAnimal waste based biomass is limitedHarmful emission released if combusted wronglyCause to air pollution

Biomass?


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HYDROGEN?

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Hydrogen???

ENERGY

1 kg Hydrogen = 2.1 kg Natural gas= 2.8 kg Petroleum

Mostabundantelement in the

nature

Not availablefree

Environmentalfriendlyand

renewable

Biomass

WaterWindSunGeothermal

Nuclear

Petroleum

Coal

Natural gas

HYDROGEN ENERGY SYSTEM

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FUEL CELLS?

35 36

Fuel cell: Multidisciplinary!

FUEL CELL

Electrical-electronics

engineering

Material

science

Chemical engineeringMechanical

engineering

Control engineering

Chemistry


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NASA Space studies

1839

1932

1952

Recenthistory

Invention

Developmentstudies

1960 Tractor1980 Train1990 Submarinesand aircraft

TodayLand vehiclesPower plantsElectronicdevices

Fuel Cells - The First 120 Years

In 1800, British scientists William Nicholson and Anthony Carlisle haddescribed the process of using electricity to decompose water intohydrogenand oxygen

British judge and scientist, Sir William Robert Grove in his

experiments in 1839 on electrolysis - the use of electricity to splitwater into hydrogen and oxygen - led to the first mention of a devicethat would later be termed the fuel cell

Grove reasoned that it should be possible to reverse the electrolysisprocess and generate electricity from the reaction of oxygen withhydrogen

Groves Test

He enclosed two platinum strips in separate sealed bottles, onecontaining hydrogen and one oxygen.

When these containers were immersed in dilute sulphuric acid acurrent began to flow between the two electrodes and water wasformed in the gas bottles.

In order to increase the voltage produced, Grove linked several ofthese devices in series and produced what he referred to as a gasbattery.

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Fuel Cells - The Next 40 Years

The recent history of the fuel cell can be thought of as beginning inthe early 1960s.

A new US government agency, the National Aeronautics and SpaceAdministration (NASA), was looking for a way to power a series of

upcoming manned space flights.

NASAhad already ruled out using batteries as they were too heavy

solar energy as it was too expensive

nuclear power as it was too risky

This search led to the development of the first Proton ExchangeMembrane (PEM).

Cont.. An oil embargo in 1973 kick-started renewed interest in fuel cell power for

terrestrial applications as governments looked to reduce their dependence onpetroleum imports.

A number of companies and government organisations began to undertake seriousresearch into overcoming the obstacles to widespread commercialisation of thefuel cell.

Throughout the 1970s and 1980s a huge research effort was dedicated todeveloping the materials needed, identifying the optimum fuel source anddrastically reducing the cost of this exotic technology.

Finally, in the 1990s, over 150 years after Grove's experiments, the promise ofinexpensive, clean, renewable energy began to look as if it might become reality asthe first viable fuel cells were unveiled.

In the last few years we have seen fuel cells installed in hospitals and schools andmany of the major automotive companies have unveiled prototype fuel cellpowered cars.


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Fuel cell: Key notes. Fuel cells started with Sir William Grove in 1839

The term 'fuel cell' was coined by the chemists Ludwig Mond and Charles Langer in 1889 asthey attemptedto build the firstpractical device usingair and industrialcoal gas

It was not too successfulinitially becausenot enough wasknown about electricity

The first success was by Francis Bacon in 1932 (Alkaline fuel cell system with porouselectrodes)

In 1950s, fuel cells were used in the Apollo space programme

Reason for spaceuse: Nuclear too dangerous,solar too bulky, batteriestoo heavy

Fuel cells used in Apollo, Gemini and spaceshuttles

For fuel cell vehicles, General Motors developed a six-passenger Electrovan in 1967, but on lyfor use on companypropertydue to safetyreasons

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MK900 MK800 MK700 MK500 MK300

(2000) (1997) (1995) (1993) (1991)

(80 kW) (50 kW) (25 kW) (10 kW) (5 kW)

BALLARD

Advantages:

1) Fuel cells have high efficiency. It is nearly 70% while other sources have efficiency 15-20%(gasoline engine) and 30-35%(diesel engine).

2) The efficiency of the fuel cell does not depend on the size of the power plant.

3) Maintenance cost is very low.

4) Fuel cells are more efficient in producing the mechanical power to drive the vehicles andrequire less energy consumption.

Disadvantages:

1) Initial cost of fuel cell is high.

2) Life time of fuel cell is not known accurately.

3)There is a problem of durability and storage of large amount of hydrogen

Conventional electricity generation

with a fuel

Electricity generation with

Fuel Cell

Chemical Energy

Heat

Mechanical Energy

Electrical Energy

Chemical Energy

Electrical Energy

(Combustion)

(PV work)

(Electromagnetic

induction)

(Redox

reactions)

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Energy conversion for electrical energy

Fuel cell

Chemical Electricity

Battery

Chemical Electricity

Heat engines

Chemical Heat Mechanical Electricity

Energy conversion for mechanical energy

Fuel cell

Chemical

Battery

Chemical

Heat engines

Chemical Heat Mechanical

E le ctri ci ty M ec hani cal

E le ctri ci ty M ec hani cal

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Heat engines

In a combustion process which is largely

irreversible, chemical bond energy of fuel

converted to the internal energy of the

combustion products and this energy is used

after conversion to the mechanical work in a

heat engine.

Chemical Heat Mechanical Electrical


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Heat engines

Steam is formed withheat and the pressure

rise

Pressurized steammakes work by

running the piston or

shaft

Exhaust steam tookaway the waste heat

Cycle is completed

Heat Engines

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Heat Engines

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Basic heat engine cycle

Volume

Pressure

B

C

D

A

AB Heat inlet

BC work is done byexpanding the fluid at hightemperature

CD Heat outlet

DA work needed for thecompression of fluid

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Heat engines

What happens when gas(steam) expands doingwork?

PV/RT=constant

Volume increases andtemperature of the steameither increases or staysthe same.

After the stroke doingwork how do we return tothe starting condition?

Psteam

Qin

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Thermodynamics

Energy is alwaysconserved

Energy is alwaystransferred to down

Heat is transferredfrom high temperatureto low temperature

Cold Hot

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The max efficiency that can be

reached with a heat engine is

limited with Carnot cycle

efficiency, due to mechanical

and thermal stresses of the

materials, in reality the maxefficiency stands at 40 %.

Cold Hot

Carnot efficiency


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55

Diesel machine

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Diesel cycle

Isobaric combustion

Fuel is injected to the hot air aftercompression provides highercompression ratios

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

20 40 60 80 100 120Volume (cm3)

Pressure

(bar)

Compression

Heating

Expansion

HeatRejection

Exhaust

Intake

Primary BatteriesLithium cell, Leclanche cell

Secondary BatteriesLead-acid Batteries, Nicad Batteries, Lithium-ion Batteries

BATTERIES

Battery :-

Definition :

A battery is a storage device used for the storage of chemical energy and for thetransformationof chemical energy into electrical energy

Battery consists of group of two or more electric cells connected together electrically inseries.

Battery acts as a portable source of electrical energy.

Energy produced by an electrochemical cell is not suitable for commercial purposes sincethey use salt bridge which produce internal resistance which results in drop in the voltage.The drop in voltage is negligible only for a small interval of time during which it is beingused.

Batteries are of2 types. Namely

Primary Batteries (or) Primary Cells

SecondaryBatteries (or) SecondaryCells

I. Primary Batteries (or) Primary Cells :-

Primary cells are those cells in which the chemical reaction occurs only once and the cellbecomes dead after sometime and it cannot be used again. These batteries are used assource of dc power.

Eg. Dry cell (Leclanche Cell) and Mercury cell, lithium cell.

Requirements of Primary cell:

It should satisfy these requirements

1) It must be convenient to use.

2) Cost of discharge should be low.

3) Stand-by power is desirable.

B. Leclanche Cell (or) Dry Cell :

Batteries

Dry battery

Zn (s) Zn2+ (aq) + 2e-Anode:

Cathode: 2NH4+ (aq) + 2MnO2 (s) + 2e

- Mn2O3 (s) + 2NH3 (aq) + H2O (l)

Zn (s) + 2NH4 (aq) + 2MnO2 (s) Zn2+ (aq) + 2NH3 (aq) + H2O (l) + Mn2O3 (s)

Composed of two electrodes madeup of d if fe rent met al scontacted with a conductingelectrolyte. Current flows frompositive electrode to negative

electrode until the chemicalchange stops.


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Advantages:

1) These cells have voltage ranging f rom 1.25v to 1.50v.2) Primary cells are used in the torches,radios,transistors,hearing

aids,pacemakers,watches etc.3) Price is low.

Disadvantages:

These cells does not have a long life, because the acidic NH4Cl corrodes the containereven when the cell is not in use.

II. SecondaryCells (or) Accumulatorbatteries :-

These cells can be recharged by passing an electric current through them and can be used againand again.

Eg: A. Lead storagebattery

B. Nickel-Cadmium battery

C. Lithium-ion cell battery

Secondary cells are widely used in cars,trains,motors,electric clocks, power stations,laboratories, emergency lights, telephoneexchange, digital cameras, laptops etc.

These are reversible cells, they behave as galvanic cell while discharging and as electrolytic cellwhile charging.

Lead storage battery

Batteries

Anode:

Cathode:

Lead storage battery

PbO2 (s) + 4H+ (aq) + SO4

2- (aq) + 2e- PbSO4 (s) + 2H2O (l)

Pb (s) + SO42- (aq) PbSO4 (s) + 2e

-

Pb (s) + PbO2 (s) + 4H+ (aq) + 2SO4

2- (aq) 2PbSO4 (s) + 2H2O (l)

Batteries

Zn(Hg) + 2OH- (aq) ZnO (s) + H2O (l) + 2e-Anode:

Cathode: HgO (s) + H2O (l) + 2e- Hg (l) + 2OH- (aq)

Zn(Hg) + HgO (s) ZnO (s) + Hg (l)

Mercury battery

Distinction between Primary, Secondary & Fuel cells

Primary Secondary Fuel cells

1) It only acts as galvanicor voltaic cell. i.e.,produces electricity

1) It acts as galvanic orvoltaic cell whiledischarging (produceselectricity) and acts aselectrolytic cell (consumeselectricity)

1) It is a simple galvanic orvoltaic cell. i.e., produceselectricity

2) Cell reaction is notreversible.

2) Cell reaction isreversible.

2) Cell reaction isreversible.

3) Cant be recharged. 3) Can be recharged 3) Energy can bewithdrawn continuously

4) Can be used as longas the active materialsare present

4) Can be used again andagain by recharging.

4) Reactants should bereplenished continuously. itdoes not store energy.

eg: Leclanche cell or Drycell, Lithium cell.

eg: Lead storage battery, Ni-Cd battery, Lithium ion cell

eg: H2&O2 Fuel cell

CH3OH &O2 Fuel cell

Uses: In Pace makerswatches, Transistors, radiosect.

Uses: In electronicequipments, automobileequipments, digital cameras,laptops, flash light.

Uses: Great use in spacevehicles due to its light weight(product of is source of freshwater for astronauts )


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Space studies

Militaryapplications

Residentialapplications

Stationarypower systems

Portable power source

Waste/ waste water applications

Transportation applications

Fuel cell applications

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Ford TH!NK FCV

Honda FCX V3 Nissan Xterra FCV

DaimlerChrysler Necar4DaimlerChrysler JeepComm

Mazda Premacy FC-EV


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Ballard 250kW natural gassuppliedfuel cell

Ha s 9 t ria l c ou rts in n or ther n Ame ri ca ,Europeand Japan

1999 - Crane, India

2000 - Berlin, Germany 2000 Tokio, Japan


76DaimlerChrysler Necar 5

The firstfuelcellcaralong America

From San Francisco

to

Washington D.C.

20 May 4 June

2002

With MeOH fuel


Automotive Industry

Considered to be the first gasoline powered fuel cell vehicle is the H 20 by GM:

GMC S-10(2001)fuelcell battery hybridlow sulfur gasoline fuel25kW PEM40mpg112 km/htopspeed

Fords Adavanced Focus FCV (2002)fuel cell battery hybrid85 kW PEM~50 mpg (equivalent)4 kg of compressed H2 @ 5000 psi


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Daimler-Chrysler NECAR 5 (introduced in 2000)

85 kW PEM fuel cell

methanol fuel

reformer required

150 km/h top speed

Mitsubishi GrandisFCV minivan

fuel cell / battery hybrid

68 kW PEM

compressed hydrogen fuel

140 km/h top speed

Stationary Power Supply Units

A fuel cell installed at McDonalds restaurant, Long Island Power Authority to install 45more fuelcellsacross Long Island,including homes.Feb 26,2003

More than 2500 stationary fuel cell systems have been installed all over the world - inhospitals, nursing homes, hotels, office buildings, schools, utility power plants, and anairportterminal, providing primary power or backup. In large-scale building systems, fuelcells can reducefacility energy service costs by 20%to 40% over conventional energyservice.

Residential Power Units

There are few residential fuel cel l power uni ts on the market but many designs areundergoing testing and should be available within the next few years. The majortechnical difficulty in producing residential fuel cells is that they must be safe to install ina home, andbe easilymaintainedby theaverage homeowner.

Residential fuel cells are typically thesize of a large deep freezer or furnace,such as the Plug Power 7000 unitshownhere,and cost $5000- $10 000.

I f a power company was to install a residential fuel cel l power uni t in a home, i t would

haveto chargethe homeownerat least 40 /kWh to be economically profitable. They willhaveto remaina backup power supplyfor thenear future.

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Residential PEM fuel cell cogeneration system

84


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References

http://www.clarkson.edu/highschool/k12/project/documents/energysystems/LP_3fuelcell.pdf

Inventory of U.S. Greenhouse Gas Emissions a nd Sinks (2008), EPA

http://scienceblogs.com/seed/nuclear_power_plant.gif

http://tajikwater.net/img/hydropower_2.jpg

http://s1.hubimg.com/u/484084_f496.jpg

http://www.iaacblog.com/2008-2009/term02/rs2/wp-content/uploads/2009/01/biomass-energy-co2-cycle-thumb-425x373.jpg

http://www.edinformatics.com/math_science/alternative_energy/biomass/BIOMASSTYPES1.gif

http://cset.sp.utoledo.edu/~energy/Fuel%20Cell/HIMALAY/Fuel%20Cell%20History.ppt

http://policy.rutgers.edu/ceeep/hydrogen/education/IntroFuelCells.pdf

http://www.sakshieducation.com/(S(l5pr1kebnwnwn1qz0kvggg55))/Engg/EnggAcademia/CommonSubjects/EnggChemistryUnit-I.ppt

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fuelcells 1.pdf

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