Date post: | 16-Apr-2017 |
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Hydrogen Fuel Cells
From- Vipan Kumar1307570B.Tech EE ,7th sem
Submitted To:Mr. Akshay AgnihotriAsst. Prof. EE department
• Simplest element in universe- one proton and one electron.
• Occurs naturally as a gas. • Can be used to create energy through combustion or
use in fuel cells.• Colorless• Tasteless• Odorless• Slightly soluble in water• Highly explosive
Definition of Hydrogen
Definition of Fuel Cell
• Produces electricity through a chemical reaction, but without combustion.
• Converts hydrogen and oxygen into water. 2H2 + O2 → 2H2O• Operates much like a battery, except they don’t
require electrical recharging.• Can generate power almost indefinitely, as long as
they have fuel to use.
What is a Hydrogen Fuel Cell?•Hydrogen fuel cells (HFCs) are a type of electrochemical cell.
•HFCs generate electricity by reduction and oxidation reactions within the cell.
•They use three main components, a fuel, an oxidant and an electrolyte.
•HFCs operate like batteries, although they require external fuel.
•HFCs are a thermodynamically open system.
•HFCs use hydrogen as a fuel, oxygen as an oxidant, a proton exchange membrane as an electrolyte, and emit only water as waste.
How do they work?•Fuel (H2) is first transported to the anode of the cell
•Fuel undergoes the anode reaction
•Anode reaction splits the fuel into H+ (a proton) and e-
•Protons pass through the electrolyte to the cathode
•Electrons can not pass through the electrolyte, and must travel through an external circuit which creates a usable electric current
•Protons and electrons reach the cathode, and undergo the cathode reaction
Chemistry behind the technologyOxidation
At the anode of the cell, a catalyst (platinum powder) is used to
separate the proton from the electron in the
hydrogen fuel. Anode half-reaction:
2H2 4H+ + 4e-
Eo = 0.00V
Reduction
At the cathode of the cell, a second catalyst (nickel) is
used to recombine the protons, electrons, and
oxygen atoms to form water. Cathode half- reaction:4H+ + O2 + 4e- 2H2O
Eo = 0.68V
In electrochemistry, the Eocell value (energy) of a fuel cell is equal to the Eo
of the cathode half-reaction minus the Eo of the anode half-reaction. For a
hydrogen fuel cell, the two half reactions are shown above. So to calculate the energy of one fuel cell, we need to subtract the anode energy from the cathode energy. For a HFC, the Eo
cell = 0.68V – 0.00V which equals 0.68V
Efficiency of Hydrogen Fuel Cell• If the fuel cell is powered with pure hydrogen, it has the
potential to be up to 80-percent efficient. • Honda's FCX concept vehicle reportedly has 60-percent
energy efficiency.• Hydrogen fuel cells are very efficient compared to what we
have now.
Hydrogen Technology Development in India
• Production of hydrogen by photo electrolysis of water using solar energy.
• Production of hydrogen by blue green algae & by certain bacterial species.
• Storage of hydrogen through metal hydride/non-metal hydride.
• Problems relating to utilization of hydrogen as a fuel, i.e., developed for certain engines and fuel etc.
• Liquid hydrogen production, storage and utilization.
Uses of Hydrogen Fuel CellsThere are many different uses of fuel cells being utilized right now. Some of these uses are:•Power sources for vehicles such as cars, trucks, buses and even boats and submarines
•Power sources for spacecraft, remote weather stations and military technology
•Batteries for electronics such as laptops and smart phones
•Sources for uninterruptable power supplies.
Hydrogen Fuel Cell Vehicles• A hydrogen fuel cell vehicle is a type of electric vehicle that uses a fuel
cell instead of a battery to power the car. • FCVs have a driving range similar to a vehicle with an internal combustion
engine – 250 to 400 miles per tank of fuel. • FCVs are commercially available for lease, but hydrogen refueling
infrastructure does not exist yet in most parts of the country. • California has a few stations in operation, and more under construction.• Although the cost of hydrogen is more expensive than gasoline on an
energy equivalent basis, because the electric drive system is two to three times more efficient than an internal combustion.
Hydrogen Fuel Cell Vehicles• The 2015 Toyota Mirai is one of the first hydrogen fuel cell
vehicles to be sold commercially. The Mirai is based on the Toyota FCV concept car
• Honda FCX Clarity, a hydrogen fuel cell demonstration vehicle introduced in 2008
Advantages of Hydrogen Fuel Cells
• It is readily available.• It doesn’t produce harmful emissions.• It is environmentally friendly.• It can be used as fuel in rockets.• It is fuel efficient.• It is renewable.
Disadvantages of Hydrogen Fuel Cells
• H2 is difficult/expensive to produce, store and transport.
• Fuels cells require pure fuel.• Platinum catalysts are expensive and rare.• Proton exchange membranes must be kept moist.• Hydrogen fuel cell stacks are heavy.
Problems regarding Hydrogen Fuel CellsLack of hydrogen infrastructure
•Need for refueling stations
•Lack of consumer distribution system
Cost of hydrogen fuel cells
•2009 Department of Energy estimated $61/kw
•Honda FCX Clarity costs about half a million dollars to make
Carbon cost of producing hydrogen
Problems with HFC cars
•Short range (~260 miles)
•Warm up time (~5 minutes)
The Future of Hydrogen• In the future, hydrogen will join electricity as an
important energy carrier, since it can be made safely from renewable energy sources and is virtually non-polluting.
• It will also be used as a fuel for ‘zero-emissions’ vehicles, to heat homes and offices, to produce electricity, and to fuel aircraft.
• Hydrogen has great potential as a way to reduce reliance on imported energy sources such as oil
Important facts about Hydrogen Fuel Cells
• NASA is the most famous supporter of hydrogen fuel cells, this is because they use them to power their rockets.
• The United States has produced 19.8 billion pounds of hydrogen, this is enough hydrogen to power 20-30 million cars.
• Hydrogen is 14 times as light as air.• The hydrogen power that is produced in today’s world is
mostly used to refine gasoline.• During the Winter 2010 Olympics, hydrogen fuel cell buses
where used as transportation for tourists and Olympic attendees.
References•http://www.fueleconomy.gov/feg/fuelcell.shtml
•http://www.howstuffworks.com/fuel-efficiency/alternative-fuels/fuel-cell.htm
•http://www.energy.gov
•Chemical Principles, Sixth Edition, Zumdahl