Fuel Cell

What is fuel cell?

A fuel cell is a device that generates

electricity by a chemical reaction.

History: 1801: Humphry Davy demonstrates the principle of

what becomes the fuel cell

1839: William Grove invents the gas battery, the first fuel cell

1889: Charles Langer and Ludwig Mond develop

Grove’s invention and name it fuel cell.

1950: General Electric invents the proton exchange membrane fuel cell.

1959: Francis Bacon demonstrates a 5kW alkaline fuel cell.

1960: NASA first uses fuel cell in space

mission.

1970: The oil crisis prompts the development

of alternative energy technologies including

PAFC

1980s: US Navy uses fuel cells in submarines.

1990s: Large stationary fuel cells are

developed for commercial and industrial

location.

2007: Fuel cell begin to be sold commercially

as APU and for stationary backup power.

2008: Honda begins leasing the FCX clarity

fuel cell electric vehicle.

History:

Harnessing Hydrogen Steam reforming is a method for producing hydrogen,

carbon monoxide, or other useful products from

hydrocarbon fuels such as natural gas. This is achieved in

a processing device called a reformer which

reacts steam at high temperature with the fossil fuel.

CH4 + H2O ⇌ CO + 3 H2

CO + H2O ⇌ CO2 + H2

Harnessing Hydrogen In chemistry and manufacturing, electrolysis is a

technique that uses a direct electric current (DC) to

drive an otherwise non-spontaneous chemical

reaction. Electrolysis is commercially highly important as

a stage in the separation of elements from naturally

occurring sources such as ores using an electrolytic cell.

Collecting hydrogen generated as a waste product by

some strains of algae and bacteria.

2 NaCl + 2 H2O → 2 NaOH + H2 + Cl2

2 H2O(l) → 2 H2(g) + O2(g)

Proton Exchange Membrane

Efficiency is about

40% to 50%, and

operating

temperature is

about 80˚C. Uses

Hydrogen and

Oxygen to produce

electricity

Direct-methanol Fuel CellsSubcategory of proton-

exchange fuel cells in

which methanol is used as

the fuel. Their main

advantage is the ease of

transport of methanol, an

energy-dense yet

reasonably stable liquid at

all environmental

conditions.

Alkali Fuel CellAlkali fuel cells operate on

compressed hydrogen and oxygen.

They generally use a solution of

potassium hydroxide in water as their

electrolyte. Efficiency is about 70 %,

and operating temperature is 150 ˚C

to 200 ˚C. Alkali cells were used in

Apollo spacecraft to provide both

electricity and drinking water. They

require pure hydrogen fuel, however,

and their platinum electrode catalysts

are expensive. And like any container

filled with liquid, they can leak.

Molten Carbonate Fuel CellsUses high-temperature

compounds of salt carbonates

as the electrolyte. Efficiency

ranges from 60% to 80%, and

operating temperature is

about 650 ˚C. Their nickel

electrode-catalysts are

inexpensive compared to the

platinum used in other cells. But

the high temperature also limits

the materials and safe uses of

MCFCs–they would probably

be too hot for home use.

Phosphoric Acid Fuel CellsUses phosphoric acid as the

electrolyte. Efficiency ranges from

40-80%, and operating

temperature is between 150 ˚C to

200 ˚C. PAFCs tolerate a carbon

monoxide concentration of about

1.5%, which broadens the choice

of fuels they can use. If gasoline is

used, the sulfur must be removed.

Platinum electrode-catalysts are

needed, and internal parts must

be able to withstand the corrosive

acid.

Solid Oxide Fuel CellsUses a hard, ceramic compound of

metal oxide as electrolyte. Efficiency

is about 60%, and operating

temperatures are about 1,000 ˚C. At

such high temperatures a reformer is

not required to extract hydrogen

from the fuel, and waste heat can

be recycled to make additional

electricity. However, the high

temperature limits applications of

SOFC units and they tend to be

rather large. While solid electrolytes

cannot leak, they can crack.

DISADVANTAGES Efficiency - Fuel cells are generally more

efficient than combustion

Simplicity - Fuel cells are essentially simple

with few or no moving parts. High reliability

may be attained with operational lifetimes

exceeding 40,000 hours.

Low emissions - Fuel cells running on direct

hydrogen and air produce only water as

the byproduct.

Silence - The operation of fuel cell systems

are very quiet with only a few moving parts

if any.

Flexibility - Modular installations can be

used to match the load and increase

reliability of the system.

Cost - The principal

disadvantages of fuel

cells, however, are

the relatively high cost

of the fuel cell, and to

a lesser extent the

source of fuel.

ADVANTAGES

Application Combined Heat and Power Systems

The primary stationary application of fuel cell technology is for the combined

generation of electricity and heat, for buildings, industrial facilities or stand-by

generators. Because the efficiency of fuel cell power systems is nearly unaffected by

size, the initial stationary plant development has focused on the smaller, several

hundred kW to low MW capacity plants. “The plants are fuelled primarily with natural

gas, and operation of complete, self-contained, stationary plants has been

demonstrated using PEMFC, AFC, PAFC, MCFC, SOFC technology”

Portable Electronic Equipment

fuel cells could replace batteries that power consumer electronic products such

as cellular telephones, portable computers, and video cameras. Unlike transportation

applications where fuel cells are competing with the internal combustion engines to

indirectly produce a mechanical output, in portable electronic equipment fuel cells

are in competition with devices such as batteries to produce an electrical output. As

a result fuel cells can offer a viable alternative to batteries and several low power

fuel cells are currently being manufactured for this application.

fin

LIST OF COMPANIES

BallardPowerSystems - Burnaby, Canada

FuelCellEnergy - Danbury, Connecticut, United States

Hydrogenics Corporation - Mississauga, Canada

PlugPower - Latham, New York, United States

HyperSolar - Santa Barbara, CA

Ceres Power - United Kingdom

Ceramic Fuel Cells - Noble Park, Australia

Proton Power Systems - Wallingford, Connecticut, US

AFC Energy - Surrey, United Kingdom

ITMPowerPLC - Sheffield, United Kingdom