Download A Fuel Cell Future

A FUEL CELL FUTURE!
Understanding how Hydrogen Fuel Cells work and their
potential to revolutionise transportation
Nicola Ruston, Mark Ormerod and Zoe Robinson
School of Physical and Geographical Sciences, Keele University
Our transport choices have a huge impact on climate change. The average car in the UK today emits nearly 200 grams of carbon dioxide
for every kilometre travelled. On average we each travel nearly 10,000 km by car every year. That adds up to more than 1.5 tons of CO2
emitted per person each year just for travelling by car!
We can make a huge difference to climate change by changing the way we travel, and by choosing cleaner cars!
Different Types of Fuel Cells...
What is a Fuel Cell?...
A fuel cell is a device that uses fuel (typically hydrogen or a hydrogen-rich
fuel) and oxygen to create electricity by an electrochemical process. A
single fuel cell consists of an electrolyte and two catalyst-coated
electrodes (a porous anode and cathode).
There are several different kinds of fuel cells, but Proton
Exchange Membrane (or Polymer Electrolyte Membrane) (PEM)
fuel cells are the type used in vehicles.
A PEM fuel cell uses HYDROGEN fuel and OXYGEN from the air to
produce electricity.
and how does it work?...
A PEM fuel cell uses a simple electrochemical reaction to
combine hydrogen and oxygen into water, producing an
electric current in the process.
How the PEM Fuel Cell Works
1. At the anode, on the surface of the platinum-based
catalyst, hydrogen molecules are dissociated into H atoms
and lose their electron forming protons (H+).
2. The solid polymer electrolyte is a proton conductor and
allows protons to pass through it, but not electrons. As a
result protons pass directly through the electrolyte to the
cathode, while the electrons flow round an external circuit
There are several different types of fuel cells. Fuel cells are
usually classified by their operating temperature and the type of
electrolyte they use.
The Solid Oxide Fuel Cell (SOFC) operates at high temperatures
and is particularly suited to stationary power generation and are
extremely efficient producing useful heat. PEM fuel cells operate
at low temperature and are particularly suited to small portable
applications and for powering vehicles.
Fuel Cells
5. The protons react with the oxygen ions to form water,
which is the only product formed:
2
H+
+
O2-
 H2O
HYDROGEN - The Fuel of the Future
Advantages of using hydrogen
Hydrogen has many advantages over other
AND most importantly...
fuels, it is;
When hydrogen burns it
• non-toxic
produces only water –
• renewable
therefore it does not pollute
the atmosphere or
• clean
contribute to global
• more energy efficient than fossil fuels warming!
contains more energy per kg.
…But how safe is Hydrogen?
Since any fuel we use is flammable, it is inherently dangerous.
However hydrogen is non-toxic, so it is not harmful to breathe and is
also so light that it scatters immediately upward when there is a leak,
rather than pooling about, polluting groundwater, and soaking into
clothes.
When hydrogen is handled with care appropriate to any gaseous
fuel, it is actually far safer than fuels in standard use today!
Visit our website: www.esci.keele.ac.uk/sfs
Combustion Engine
Fuel cells have several benefits over conventional combustion-based
technologies currently used in many power plants and in vehicles.
They produce much smaller quantities of greenhouse gases and
none of the air pollutants that create smog and cause health
problems. If pure hydrogen is used as a fuel, fuel cells emit only
heat and water as a by-product.
Fuel cell powered vehicles are three times more efficient
than internal combustion engines, which only operate at 1016% efficiency.
3. As they flow round the external circuit, the electrons
produce an electrical current. This current can power any
electrical device (such as an electric motor or a light bulb).
4. At the cathode oxygen molecules are dissociated to form
oxygen atoms, which gain electrons to form oxygen ions (O2-)
vs.
Fuel Cell Vehicles
Although fuel cell vehicles are not expected to reach the mass market
before 2010, this technology has the potential to massively reduce
energy use and emissions responsible for climate change
Like battery-electric vehicles, FCVs are powered by electric motors. But
while battery electric vehicles use electricity from an external source (and
store it in a battery), FCVs create their own electricity on-board the vehicle,
using hydrogen fuel and oxygen from the air.
“Hydrogen cars are not only the future, they are here, now!”
Ford, GM, Honda, Toyota, and Mercedes Benz have all already
demonstrated fuel cell vehicles
(Under the hood of the GM
HydroGen3 )
(DaimlerChrysler's F-Cell AClass Mercedes)
(Hydrogen refuelling station )
(General Motor's fuel-cell
HydroGEN3 prototype)
A CLEANER FUTURE FOR BUSES
In January 2007, London completed a trial for the first
generation of zero-emission fuel cell buses!
REMEMBER…
Energy is required to produce hydrogen, so for fuel cell vehicles to be truly
"zero emission", the hydrogen fuel must be produced using a renewable
energy source, such as hydro, wind or solar power.
‘Being Greener and Cleaner’ project contact details
Dr Zoe Robinson
[email protected]
Prof. Mark Ormerod [email protected]
Nicola Ruston
[email protected]
(01782) 734303
(01782) 733475
(01782) 733161