Policy.rutgers.edu Ceeep Hydrogen Education IntroFuelCells

7/30/2019 Policy.rutgers.edu Ceeep Hydrogen Education IntroFuelCells

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What is a Fuel Cell?

Quite simply, a fuel cell is a device that converts chemical energy intoelectrical energy, water, and heat through electrochemical reactions.

Fuel and air react when they comeinto contact through a porousmembrane (electrolyte) which separates

em.

This reaction results in a transfer ofelectrons and ions across the electrol tefrom the anode to the cathode.

If an external load is attached to this

,and a voltage is generated from the flowof electrical current.

The voltage generated by a single cell is typically rather small (< 1 volt), so many

cells are connected in series to create a useful voltage.


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Fuel Cell Vs. Battery

H dro en fuel cell

Basic operating principles of both are very similar, but there are severalintrinsic differences.

Open systemAnode and cathode are gases in

contact with a platinum catalyst.

Closed systemAnode and cathode are metals.Reactants are internally consumed,

,no recharging required.

nee per o c rec arg ng.


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Fuel Cell Vs. Internal Combustion Engine

Similarities:

Both use hydrogen-rich fuel. Both use compressed air as the oxidant. Both require cooling.

Differences:

Fuel cell: Output is electrical work. Fuel and oxidant react electrochemically.

e o no po u on pro uce .

I.C. Engine:

. Fuel and oxidant react combustively.

Use of fossil fuels can produce significant pollution.


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Some History

Fuel cell principle first discoveredby William Grove in 1839.

Grove used four large cells, eachcontaining hydrogen and oxygen,

then used to split the water in the

smaller upper cell.

Commercial potential first demonstrated by NASA in the 1960s with theusage of fuel cells on the Gemini and Apollo space flights. However, these

.

Fuel cell research and development has been actively taking place since the1970s, resulting in many commercial applications ranging from low cost portablesystems for cell phones and laptops to large power systems for buildings.


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Fuel Cells in Use: Stationary Systems

Fuel cell system for submarine


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Fuel Cells in Use: Transportation Systems

Buses are most commerciallyadvanced applications of fuelcells to date.

Are currently being used by

cities.

XCELLSiS fuel cell bus prototypes


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Fuel Cells in Use: Transportation Systems

Many of the major car companies are developing fuel cell car prototypeswhich should come to market during the next decade. The cars use eitherpure hydrogen or methanol with an on board reformer.


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Fuel Cells in Use: Hydrogen Fuel Cell System


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Fuel Cells in Use: Space Systems

12 kW Space shuttle fuel cell. po o ue ce

Apollo used two of theseunits.

Weight: 120 kgSize: 36x38x114 cmContains 32 cells in series


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Fuel Cells in Use: Portable Systems

A laptop using a fuel cell power source

can operate for up to 20 hours on asin le char e of fuel Courtes : BallardPower Systems)


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But Isnt Hydrogen Explosive?

Many have blamed this disaster ona hydrogen explosion. However,hydrogen burns invisibly, and no

(garlic scent added to hydrogen gas).

Using infrared spectrographs, NASAscientists found that the skin of the

Hindenburg was treated with compounds

rocket fuel (nitrates and aluminumpowder). This, combined with a woodenframe coated with lacquer resulted in

a highly flammable ship.


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Terminology (cont.)

Catalyst: A substance that participates in a reaction, increasing its rate,but is not consumed in the reaction.

Polymer: A natural or synthetic compound made of giant molecules whichare composed of repeated links of simple molecules (monomers).

Inverter: A device used to convert direct current electricity produced by afuel cell to alternating current.

e ormer: ev ce a ex rac s pure y rogen rom y rocar ons.

Stack: Individual fuel cells connected in series within a generating assembly.


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Overview of Operating Principles

Will now look at in more detail:

-Thermodynamic principles of fuel cells.

- Fuel cell com onents.

- Fuel cell support systems.

- .

Policy.rutgers.edu Ceeep Hydrogen Education IntroFuelCells

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