HYDROGEN as an Alternative Source of Energy

8/2/2019 HYDROGEN as an Alternative Source of Energy

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Hydrogen: as an alternative source of energy

Abstract:

We rely on energy to make our lives productive, comfortable, and enjoyable. sustaining

this quality of life requires that we use our energy resources wisely and find new resources of

energy for the future. Today most of the energy we use comes from nonrenewable energy

sources such as coal, natural gas, petroleum. 83% of the energy we use comes from fossil fuels,

which can pollute the environment when they are burned. Traditional fossil energy sources

such as oil are ultimately limited and the growing gap between increasing demand and

shrinking supply will, in the not too distant future, have to be met increasingly from alternative

primary energy sources.

This calls for immediate actions to promote greenhouse gas emissions-free energy

sources such as renewable energy sources, alternative fuels for transport and to increase energy

efficiency.

It is found that the hydrogen is a clean energy carrier that can be produced from any

primary energy source, and fuel cells which are very efficient energy conversion devices, are

attracting the attention of public and private authorities. Hydrogen and fuel cells, by enabling

the so-called hydrogen economy, hold great promise for meeting in a quite unique way, our

concerns over security of supply and climate change.

There are important and perhaps unresolved technical problems associated with using

fuel cells to power vehicles. Fuel cells can freeze and not work in cold weather and can be

damaged by impacts. Additional major problems will be the extensive and costly changes in the

national infrastructure to obtain, store, and distribute large amounts of the fuels, and in related

manufacturing.

Dept of Electrical And Electronics Engineering, SJCE Mysore Page 1


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Contents

1. Introduction.

2. History.

3. Introduction about hydrogen.

4. Necessity of using Hydrogen.

5. Hydrogen production.

6. Hydrogen storage.

7. Hydrogen transportation.

8. Utilizations of Hydrogen gas.

8.1 Fuel Cells

9. Advantages of Hydrogen

10. Hydrogen safety.

11. Hydrogen and our energy future

12. Conclusion



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1. Introduction:

Hydrogen as an energy carrier can play as an important role as an alternative to convention

fuels. The most attractive feature of hydrogen as an energy carrier is that it can be produced

from water which is abundantly available in nature. Hydrogen has the highest energy content

per unit mass of any chemical fuel and can be substituted for hydrocarbon in many application.

Its burning process is non polluting and it an be used in the fuel cells to produce both electricity

and useful heat. Hydrogen is a clean energy carrier with the potential to replace liquid and

gaseous fossil fuels in the coming decades. in recent years notable progress has been made

globally in the development and use of hydrogen energy and fuel cell technologis.

Fuel cells are important future sources of electrical power and could contribute to a

reduction in the amount of petroleum imported from foreign countries. They are

electrochemical devices similar to a battery and consist of a container, an anode, a cathode,

catalysts, an intervening electrolyte, and an attached electrical circuit. Fuel cells can poweralmost any portable application that typically uses batteries, from hand-held devices to portable

generators. Fuel cells can also power our transportation, including personal vehicles, trucks,

buses, and marine vessels, as well as provide auxiliary power to traditional transportation

technologies.

Hydrogen can play a particularly important role in the future by replacing the imported

petroleum we currently use in our cars and trucks. The hydrogen can be used as a fuel directly,

or it might be used as raw material to produce hydrocarbons by using either carbon dioxide or

nitrogen from the atmosphere.

The combination of hydrogen with oxygen result in the liberation of energy, with water as the

product.

2H2 + O2 2H2O+ energy

The reaction can be carried out and the energy made available in different ways so that

hydrogen is versatile fuel material.



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2. History

The possibility of generating electricity by reversing the electrolysis of water was

discovered by Sir William Grove in about 1839. Charles Langer and Ludwig Mond first used

the term fuel cell in 1889 while attempting to create a practical fuel cell using coal and air. In

the first few years of the 20th century, there were efforts to develop a fuel cell that would use

carbon or coal to produce electricity.

Francis Bacon developed a usable hydro-gen-oxygen cell containing an alkaline

electrolyte and nickel electrodes in 1932. However, a practical system was not demonstrated by

Bacon and his associates until 1959. In the same year, Harry Karl Ihrig presented a tractor of 20

horsepower that was powered by fuel cells.

NASA began developing a compact generator of electricity for use on space missions in

the late 1950s and fuel cells have been providing electricity and water on spacecraft since the

1960s. More recently, many companies and governmental agencies have supported researchconcerning fuel cell technology for possible use in stationary power plants, homes, vehicles,

water craft, and small electronic devices including cell phones.

3. Introduction about hydrogen.



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Hydrogen is the simplest element known to exist. An atom of hydrogen has one proton and

one electron. Hydrogen has the highest energy content of any common fuel by weight, but the

lowest energy content by volume. It is the lightest element and a gas at normal temperature and

pressure.

Hydrogen is also the most abundant gas in the universe, and the source of all the energy wereceive from the sun. The sun is basically a giant ball of hydrogen and helium gases. In a

process called fusion, four hydrogen atoms combine to form one helium atom, releasing energy

as radiation. Most of the energy we use originally came from the sun.

Hydrogen as a gas (H2), however, doesnt exist naturally on Earth. It is found only in

compound form. Combined with oxygen, it is water (H2O). Combined with carbon, it forms

organic compounds such as methane (CH4), coal, and petroleum. Hydrogen is also one of the

most abundant elements in the Earths crust. Every day we use more fuel, principally coal, to

produce electricity. Electricity is a secondary source of energy. Secondary sources of energy

energy carriers are used to store, move, and deliver energy in easily usable form. We convertenergy to electricity because it is easier for us to transport and use. Try splitting an atom,

building a dam, or burning coal to run your television. Energy carriers make life easier.

Hydrogen is one of the most promising energy carriers for the future. It is a high efficiency,

low polluting fuel that can be used for transportation, heating, and power generation in places

where it is difficult to use electricity. Since hydrogen gas is not found on Earth, it must be

manufactured. There are several ways to do this.

Figure 1: Hydrogen atom

4. Necessity of using Hydrogen



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Hydrogen is the perfect partner for electricity, and together they create an Integraed energy

system based on distributed power generation and use. Hydrogen and electricity

interchangeable using fuel cell (to convert hydrogen to electricity) or an electrolyter for

converting electricity to hydrogen. A regenerative fuel cell works either way, convertinghydrogen to electricity and vice versa.

Hydrogen is the perfect fuel because:

It can be produced from variety of energy sources.

It satisfies all energy needs from transportation to electric power generation.

It is the least polluting since its use produces water.

It is the perfect carrier for solar energy in that it affords solar a storage media.

The potential effects of climate change are very serious and most important of all,

irreversible. Now every nation is aiming for the ideal an emissions free future based on

sustainable energy. Electricity and hydrogen together represent one of the most promising ways

to achieve this, complemented by fuel cells which provide very efficient energy conversion.

Hydrogen is not a primary energy source like coal and gas. It is an energy carrier. Initially, it

will be produced using existing energy systems based on different conventional primary energy

carriers and sources. In the longer term, renewable energy sources will become the most

important source for the production of hydrogen. Regenerative hydrogen, and hydrogen

produced from nuclear sources and fossil-based energy conversion systems with capture, and

safe storage (sequestration) of CO2 emissions, are almost completely carbon-free energy

pathways. Producing hydrogen in the large quantities necessary for the transport and stationarypower markets could become a barrier to progress beyond the initial demonstration phase. If

cost and security of supply are dominant considerations, then coal gasification with CO2

sequestration may be of interest for large parts of World. If the political will is to move to

renewable energies, then biomass, solar, wind and ocean energy will be more or less

viable according to regional geographic and climatic conditions.

Fuel cells will be used in a wide range of products, ranging from very small fuel cells in

portable devices such as mobile phones and laptops, through mobile applications like cars,

delivery vehicles, buses and ships, to heat and power generators in stationary applications in

the domestic and industrial sector. Futureenergy systems will also include improved conventional energy converters running on

hydrogen (e.g. internal combustion engines, Stirling engines, and turbines) as well as other

energy carriers (e.g. direct heat and electricity from renewable energy,

and bio-fuels for transport). The benefits of hydrogen and fuel cells are wide ranging, but will

not be fully apparent until they are in widespread use. With the use of hydrogen in fuel-cell

systems there are very low to zero carbon emissions and no emissions of harmful ambient air

substances like nitrogen dioxide, sulphur dioxide or carbon monoxide. Because of their low

noise and high power quality, fuel cell systems are ideal for use in hospitals or IT centres, or

for mobile applications. They offer high efficiencies which are independent of size. Fuel-cell

electric-drive trains can provide a significant reduction in energy consumption and regulated



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emissions. Fuel cells can also be used as Auxiliary Power Units (APU) in combination with

internal combustion engines, or in stationary back-up systems when operated with reformers

for on-board conversion of other fuels saving energy and reducing air pollution, especially in

congested urban traffic. In brief, hydrogen and electricity together represent one of the most

promising ways to realise sustainable energy, whilst fuel cells provide the most efficientconversion device for converting hydrogen, and possibly other fuels, into electricity.

Todays society depends crucially on the uninterrupted availability of affordable fossil

fuels which, in future, will be increasingly concentrated in a smaller number of countries

creating the potential for geopolitical and price instability. Hydrogen opens access to a broad

range of primary energy sources, including fossil fuels, nuclear energy and, increasingly,

renewable energy sources (e.g. wind, solar, ocean, and biomass), as they become more widely

available. Hydrogen and electricity also allow flexibility in balancing centralized and

decentralised power, based on managed, intelligent grids, and power for remote locations (e.g.

island, and mountain sites). Decentralised power is attractive both to ensure power quality to

meet specific customer needs, as well as reducing exposure to terrorist attack. The ability to

store hydrogen more easily than electricity can help with load levelling and in balancing the

intermittent nature of renewable energy sources. Hydrogen is also one of the few energy

carriers that enables renewable energy sources to be introduced into transport systems.

Hydrogen can be produced from carbon-free or carbon-neutral energy sources or from

fossil fuels with CO2 capture and storage (sequestration). Thus, the use of hydrogen could

eventually eliminate greenhouse gas emissions from the energy sector. Fuel cells provide

efficient and clean electricity generation from a range of

fuels.

5. Hydrogen Production

Hydrogen can be produced from a variety of domestic, renewable sources of energy.



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Industry produces the hydrogen it needs by a process called steam reforming. High-

temperature steam separates hydrogen from the carbon atoms in methane (CH4). The hydrogen

produced by this method isnt used as a fuel, but for industrial processes. This is the most cost-

effective way to produce hydrogen today, but it uses fossil fuels both in the manufacturing

process and as the heat source.Another way to make hydrogen is by electrolysis splitting water into its basic elements

hydrogen and oxygen. Electrolysis involves passing an electric current through water to

separate the atoms (2H2O + electricity = 2H2 + O2). Hydrogen collects at the cathode and

oxygen at the anode.

Hydrogen produced by electrolysis is extremely pure, and electricity from renewable sources

can power the process, but it is very expensive at this time. Today, hydrogen from electrolysis

is ten times more costly than natural gas and three times more costly than gasoline per Btu.

On the other hand, water is abundant and renewable, and technological advances in renewable

electricity could make electrolysis a more attractive way to produce hydrogen in the future.

There are also several experimental methods of producing hydrogen. Photoelectrolysis

uses sunlight to split water molecules into its components. A semiconductorabsorbs the energy

from the sun and acts as an electrode to separate the water molecules.

In biomass gasification, wood chips and agricultural wastes are super-heated until they

turn into hydrogen and other gases. Biomass can also be used to provide the heat.

Nearly every region of the country (and the world) has one or more resources that can

be used to produce hydrogen. It can be produced at large central facilities or at small distributed

facilities for local use. One of its main advantages is its flexibility.

Electrolytic production of Hydrogen:

The process of splitting water into hydrogen and oxygen by means of a direct ecectric

current is known as electrolysis. In principle an electrolyte cell consist of two electrodes,

immersed in an aqueous conducting solution called electrolyte



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Figure 2: Block diagram showing Electrolysis Process

A Source of DC voltage is connected to the electrodes so that an electric current flows

through the electrolyte from the positive electode(Anode) to the negative electrode (Cathode).

As a result the water in the electrolyte is decomposed into the hydrogen gas (H2) which is

released at the cathode and oxygen gas (O2), released at the anode. Although water is split, an

electrolyte (e.g. KOH solution) is required because water itself is a very poor conductor ofelectricity.

Figure 3: Electrolysis of Water

Ideally a voltage of 1.23 volts is sufficient for the electrolysis of water at normal temperature

and pressure. The decomposition voltage increases with the current density. Since the rate ofhydrogen production is poportional to the current strength a high operating curent density is



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necesary for economic reason. In practices the decomposition voltage is usually aroung 2 volts.

The efficiency of the elerolysis is around 60% to 70%. the electolysis efficiency can be

increased by decreasing the decomposition voltage for a given current density. to achieve this

the electrode surface must be able to catalyze the electrode.

One of the best catalyst is finely devided platinum on metal base. for practical waterelecrtolysis, the electrodes are generally of nickel plated steel.

Two types of electrode arrangements are used by industry for the electrolysis of water are:

1) Tank type electrolyzer,

2) filter press or bipolar electrolyzer.

The production of hydrogen using electrolyte process can be carried out in two ways, that it

can be produced at the site of energy production or it may be produced at the point of use, as

shown in the figure.

Figure 4: The production of hydrogen at the wind farm



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Figure 5: the production of hydrogen at the point of use

In this type of hydrogen production by the process of electrolysis, it was assumed that a

signal could be sent from all three wind farms to remote electrolysis sites. This signal would

indicate to the electrolyzer when wind energy was being produced by any of the three windfarms. If wind energy was being produced, the electrolyzer would be allowed to produce

hydrogen, with certain constraints. If wind energy wasnt being produced at any of the three

wind sites, hydrogen wouldnt be produced. If only a small amount of wind energy were

produced, then only a small amount of hydrogen would be produced.

6. Hydrogen Storage

In an energy system there is need to storte energy between the production point and the

utilisation point. the need for storage is due to the mismatch between the optimum production

rate of energy and the fluctuation in demand for energy by the users.

The location of energy storage system is very important. If a very large storage system

is installed very close to the customer, the load factor on the transmission system is raised, and

there fore the transmission cost automatically becomes less.

The storage of hydrogen is not an easy problem as compared with the storage of liquid

fuels such as gasoline or oil. It is only compared with the electricity that storage of energy as

hydrogen seems relatively easier.

Ther are 5 principle methods that have been considered for hydrogen storage, these are:

1) Compressed gas storage: Hydrogen is conveniently stored for many applications in

high pressure cylinders. this method of storage is rather expensive and very bulkybecause very large quantities of steel are needed to contain quite small amounts of

hydrogen.

2) Liquid storage (Cryogenic storage in vaccum insulated or super insulated storage

tank): In this practical approach hydrogen is stored as liquid at low temperature. For

example the liquid hydrogen fuel used as rocket propellant in the space programme is

stored in large tanks. One major difference existed between handling liquid hydrogen

and liquid natural gas is the storage temperature.Liquid hydrogen boils at -2530c and

therefore it must be maintained at or below this temperature in storage.

3) Line pack system ( Allowing the pressure in the transmission or distributionsystem to vary): The use of Line pack system in the hydrogen storage system provides

a very fast response time that can take care of minute by minute or hour by hour

variations in demand.

4) Underground storage ( In depleted oil and gas fields or in aquifer systems): The

cheapest way to store large amounts of hydrogen for subsequent distribution would

probably wil be in underground facilities.

5) Storage as metal hydrides: A number of metals and alloys form solid compounds,

called metal hydrides, by direct reaction with the hydrogen gas. When the hydrogen is

heated, the hydrogen is released and the original metal is recovered for furthe use. Thus

hydrides provide a possible means of hydrogen storage.The important property of the



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metal hydrides is that the pressure of the gas released by heating a particular hydride

depends mainly on the temperature and not the composition

A variety of storage cylinders were evaluated, including standard DOT-approved steel

cylinders, conventional ground storage cylinders, and composite cylinders. From a purelyvolumetric standpoint, larger cylinders are more effective than smaller cylinders. However, the

realities of siting within an existing cell site preclude this option, at least with respect to steel.

Ground storage cylinders are typically a minimum of 10-12 feet in length, and often much

larger, and therefore were rejected due to their large size.

Composite cylinders continue to be touted as a viable storage solution, due to their light weight

and potentially higher pressure capabilities. However, these benefits come with a 3x price per

unit stored hydrogen. First, light weight is convenient for the actual installation process, but

once installed, is irrelevant. Arguments exist for using composite cylinders for rooftop

installations, and the industry anticipates a time when this will be a viable solution. For now,

the challenge of how exactly to fuel a rooftop fixed storage system remains. Secondly, the high

pressure capability can only be leveraged if there is a delivery mechanism to exploit the higher

pressure capability. High pressure refueling is currently limited to demonstration programs:

very few vehicles are available that can deliver 5,000 psi or greater. Even within this program,

the majority of vehicles available can only refuel to 2,400 psi. A program to deploy a small

fleet of higher pressure vehicles that will service 3,000 psi and higher is underway as a direct

result of this program. A third challenge with composite cylinders is that current regulations do

not adequately address composite cylinders for ground storage. Most composite cylinders that

are in use for hydrogen storage are permissible in very specific applications. The American

Society of Mechanical Engineers (ASME) is another standards organization responsible forpressure vessels. The ASME has been considering composite pressure vessels for ground

storage, and has published code cases describing a particular configuration, steel cylinders with

cylindrical composite wrapping of the cylinder, acceptable for ground storage.

7. Hydrogen Transportation



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Bulk delivery of hydrogen is a common industry practice. Industries such as petroleum

processing, metal treatment, food oil processing (hydrogenation), power generation (turbine

cooling) and semiconductor manufacturing use hydrogen as a process gas. Hydrogen is

delivered either as compressed gas, or as a liquid. These end-users are typically located inindustrial areas, with access for large vehicles, and closely monitored facilities. Serving

wireless cell sites with bulk delivery requires adapting the delivery infrastructure to meet the

characteristics of a cell site: unattended, smaller access routes, and urban, suburban, rural, and

remote locations. The wider deployment of fuel cells with refillable storage has stimulated the

evolution of delivery trucks to serve this emerging market. The first evolution phase adapts

existing trucks with capabilities to reach the HSM. The smallest existing hydrogen trailer is a

mini-tube trailer. This type of trailer consists of numerous steel tubes plumbed to a common

manifold.

Today most hydrogen is transported short distances by pipeline. Longer distance

distribution is usually by tanker trucks carrying hydrogen in liquid form. hydrogen can

permeate the natural gas pipes and fittings, causing them to become brittle and rupture. For

many applications distributed generation may be a solution. Wind turbines, solar panels and

other renewables can power electrolyzers to also prouduce hydrogen close to where it will be

used.

Liquid Hydrogen Transportation:

Hydrogen in bulk can be trasnported and distributed as the liquid. Doubled walled

insulated tanks of hydrogen with capacities of 7000 galons are carried by the road vehicles and

upto 34000 gal by rail road cars. The cost would be substantially greater than for gas pipelines.

Metal hydride transportation:

Hydrogen can also be transported as solid metal hydride. the main drawback as stated

earlier, is the weight of the hydride relative to its hydrogen content.

8. Utilisation of hydrogen gas

Many experts believe that hydrogen is an important fuel for the future. It is abundant,clean, flexible, and can be produced from many different domestic resources.

8.1 Hydrogen as a fuel in Hydrogen Fuel cells:

8.1.1 Fuel Cell Basics

A fuel cell is a device that uses hydrogen as a fuel to produce electrons, protons, heat

and water. Fuel cell technology is based upon the simple combustion reaction given in

Equation

2H2 + O2 2H2O+ energy



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The electrons can be harnessed to provide electricity in a consumable form through a

simple circuit with a load. Problems arise when simple fuel cells are constructed. Simple fuel

cells have a very small area of contact between the electrolyte, the electrode, and the gas fuel.

Simple fuel cells also have high resistance through the electrolyte as a result of the distance

between the electrodes. Therefore, as a result of these problems, fuel cells have been designedto avoid them. A design solution includes manufacturing a flat plate for the electrodes with an

electrolyte of very small thickness between the two electrodes. A very porous electrode with a

spherical microstructure is optimal so that penetration by the electrolyte and gas can occur.

This design gives the maximum area of contact between the electrodes, electrolyte and gas thus

increasing the efficiency and current of the fuel cell. A fuel cell does not require recharging the

same as a battery. In theory a fuel cell will produce electricity as long as fuel is constantly

supplied. The basic design of a fuel cell involves two electrodes on either side of an electrolyte.

Hydrogen and oxygen pass over each of the electrodes and through means of a chemical

reaction, electricity, heat and water are produced. Hydrogen fuel is supplied to the anode

(negative terminal) of the fuel cell while oxygen is supplied to the cathode (positive terminal)

of the fuel cell. Through a chemical reaction, the hydrogen is split into an electron and a

proton. Each takes a di_erent path to the cathode. The electrons are capable of taking a path

other than through the electrolyte, which, when harnessed correctly can produce electricity for

a given load. The proton passes through the electrolyte and both are reunited at the cathode.

The electron, proton, and oxygen combine to form the harmless byproduct of water. This

process is shown in Fig.

Figure 6: Basic Fell Cell Operation

The hydrogen fuel can be supplied from a variety of substances if a fuel reformer" is

added to the fuel cell system. Therefore, hydrogen can be obtained from hydrocarbon fuel suchas natural gas or methanol. The fuel cell's means for producing electricity is through a chemical



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reaction, therefore there is are significantly cleaner emissions than from a fuel combustion

process.

In a PEM fuel cell, two half-cell reactions take place simultaneously, an oxidation

reaction (loss of electrons) at the anode and a reduction reaction (gain of electrons) at thecathode. These two reactions make up the total oxidation-reduction (redox) reaction of the fuel

cell, the formation of water from hydrogen and oxygen gases. As in an electrolyzer, the anode

and cathode are separated by an electrolyte, which allows

ions to be transferred from one side to the other. The electrolyte in a PEM fuel cell is a solid

acid supported within the membrane. The solid acid electrolyte is saturated with water so that

the transport of ions can proceed.

Figure 7: PEM Fuel Cell

8.1.2 PEM Fuel Cell:

Anode reaction: H2 2H+ + 2e-

Cathode reaction: O2 + 2e- + 2H+ H2O (l)

Overall reaction: H2 + 1/2 O2 H2O (l)

At the anode, the hydrogen molecules first come into contact with a platinum catalyst

on the electrode surface. The hydrogen molecules break apart, bonding to the platinum surface

forming weak H-Pt bonds. As the hydrogen molecule is now broken the oxidation reaction canproceed. Each hydrogen atom releases its electron, which travels around the external circuit to

the cathode (it is this flow of electrons that is refered to as electrical current). The remaining

hydrogen proton bonds with a water molecule on the membrane surface, forming a hydronium

ion (H3O+). The hydronium ion travels through the membrane material to the cathode, leaving

the platinum catalyst site free for the next hydrogen molecule. Figure 12. Diagram of a single

PEM fuel cell. When an electrical load is attached across the anodeand the cathode of the fuel

cell a redox reaction occurs. The working voltage produced by one cell in this process is

between 0.5 and 0.8 volts, depending on the load. To create practical working voltages,

individual fuel cells are stacked together in series to form a fuel cell stack. At the cathode,oxygen molecules come into contact with a platinum catalyst on the electrode surface. The



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oxygen molecules break apart bonding to the platinum surface forming weak O-Pt bonds,

enabling the reduction reaction to proceed. Each oxygen atom then leaves the platinum catalyst

site, combining with two electrons (which ahave travelled through the external circuit) and two

protons (which have travelled through the membrane) to form one molecule of water. The

redox reaction has now been completed. The platinum catalyst on the cathode electrode is againfree for the next oxygen molecule to arrive.

This exothermic reaction, the formation of water from hydrogen and oxygen gases, has

an enthalpy of -286 kilojoules of energy per mole of water formed. The free energy

available to perform work decreases as a function of temperature. At 25 C, 1 atmosphere the

free energy available to perform work is about -237 kilojoules per mole. This energy is

observed as electricity and heat.

8.1.3 FUEL CELL APPLICATIONS

The applications of fuel cells vary depending of the type of fuel cell to be used. Sincefuel cells are capable of producing power anywhere in the 1 Watt to 10 Megawatt range they

can be applied to almost any application that requires power. On the smaller scale they can be

used in cell phones, personal computers, and any other type of personal electronic equipment.

In the 1kW - 100kW range a fuel cell can be used to power vehicles, both domestic and

military, public transportation is also a target area for fuel cell application, along with any APU

application. And finally, in the 1MW - 10MW range fuel cells can be used to convert energy

for distributed power uses.

Transportation:



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Fuel Cell Electric Vehicles: Automobiles

Although there are currently no Fuel cell vehiclesavailable for commercial sale, over

20 FCEVs prototypes and demonstration cars have been released since 2009. Demonstration

models include the Honda FCX Clarity, Toyota FCHV-adv, and Mercedes-Benz F-Cell.

Demonstration fuel cell vehicles have been produced with "a driving range of more than

400 km (250 mi) between refueling". They can be refueled in less than 5 minutes.

Configuration of components in a fuel cell car.

Some experts believe that fuel cell cars will never become economically competitivewith other technologies, or that it will take decades for them to become profitable. Buses,

Forklifts, Airplanes, Submarines, Motorcycles and bicycles, these are some of the types of

vehicles which uses fuel cells for their operation.

Distributed power generation

Electrical energy demands throughout the world are continuing to increase. Distributed

power plants using fuel cells can provide part of the solution. Distributed or decentralized

power plants, contrasted with centralized power plants, are plants located close to the

consumer, with the capability of providing both heat and electrical power ( a combination

known as cogeneration). Heat, the by-product of electrical power generation, is transferred

from the fuel cell to a heat exchanger. The exchanger transfers the heat to a water supply,

providing hot water to local customers.

Distributed power plants have many additional advantages. For example, they can provide

power to a remote location without the need of transporting electricity through

transmission lines from a central plant. There is also an efficiency benefit in that the cost

of transporting fuel is more than offset by the elimination of the electrical losses of

transmission. The ability to quickly build up a power infrastructure in developing nations

is often cited. Using fuel cell power plants obviates the need for an electrical grid.

http://c/wiki/Fuel_cell_vehiclehttp://c/wiki/Fuel_cell_vehiclehttp://c/wiki/Honda_FCX_Clarityhttp://c/wiki/Toyota_FCHV-advhttp://c/wiki/Toyota_FCHV-advhttp://c/wiki/Mercedes-Benz_F-Cellhttp://c/wiki/Mercedes-Benz_F-Cellhttp://c/wiki/Honda_FCX_Clarityhttp://c/wiki/Toyota_FCHV-advhttp://c/wiki/Mercedes-Benz_F-Cellhttp://c/wiki/Fuel_cell_vehicle


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Non-grid connect applications

Shown in Figure is a prototype fuel cell distributed power plant, by Ballard Power. This

unit provides 250 kilowatts of electricity and an equivalent am+ount of heat. This is enough

power for a community of about 50 homes, or a small hospital or a remote school.

Figure 8: A fuel-cell distributed power plant. This unit, produced by Ballard Power

provides 250 kilowattsheat and electricity which is enough power for an industry, a school

or a community of up to 50 homes.

(Photo courtesy of Ballard Power)

Residential Power

Fuel cell power plants are also being developed by several manufacturers to provide

electricity and heat to single-family homes. Ballard Power has developed a one-kilowatt fuel

cell designed to supply both base-load electrical power as well as heat to a dwelling. This unit

can also be fuelled by natural gas. It does not provide enough power to supply the total

electrical demands of a residence, but it does shift a portion of the demand from the electrical

grid to natural gas. The electrical efficiency of this fuel cell system is rated at 42% and the heat

efficiency is rated at 43%. Therefore the combined cogeneration efficiency of the system can

be as high as 85%.



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Figure 9: A fuel-cell power plant for residential applications provides 7 kilowatts heat and

electricity,

This is enough power for a modern energy efficient home. (Photo courtesy of Plug Power)Second generation products will be designed to run independent of the grid. During 2000, Plug

Power installed and tested 52 systems in the field and accumulated over 133,000 hours of

system run-time.

Portable Power

Several manufacturers are also developing fuel cell power supplies for portable

applications, providing a few watts up to several kilowatts of electricity (Fig. 9). Fuelled

by stored natural gas, propane, methanol or hydrogen gas, portable fuel cells may one day

replace both gasoline and diesel-engine generators for portable applications as well as

conventional batteries for uses such as remote lighting, laptop computers and mobile

phones.

Figure 10: A prototype portable fuel cell provides 50 watts electrical power.



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8.1.4 Advantages of Fuel Cells:

Fuel cells are efficient. They convert hydrogen and oxygen directly into electricity

and water, with no combustion in the process. The resulting efficiency is between 50 and 60%,

about double that of an internal combustion engine. Fuel cells are clean. If hydrogen is the fuel, there are no pollutant emissions from a

fuel cell itself, only the production of pure water. In contrast to an internal combustion engine,

a fuel cell produces no emissions of sulphur dioxide, which can lead to acid rain, nor nitrogen

oxides which produce smog nor dust particulates.

Fuel cells are quiet. A fuel cell itself has no moving parts, although a fuel cell

system may have pumps and fans. As a result, electrical power is produced relatively silently.

Many hotels and resorts in quiet locations, for example, could replace diesel engine generators

with fuel cells for both main power supply or for backup power in the event of power outages.

Fuel cells are modular. That is, fuel cells of varying sizes can be stacked together

tomeet a required power demand. As mentioned earlier, fuel cell systems can provide power

over a large range, from a few watts to megawatts.

Fuel cells are environmentally safe. They produce no hazardous waste products, and

their only by-product is water (or water and carbon dioxide in the case of methanol cells). Fuel

cells may give us the opportunity to provide the world with sustainable electrical power.

8.1.5 Obstacles

At present there are many uncertainties to the success of fuel cells and the development of a

hydrogen economy:

Fuel cells must obtain mass-market acceptance to succeed. This acceptance

depends largely on price, reliability, longevity of fuel cells and the accessibility and cost of

fuel. Compared to the price of present day alternatives e.g. diesel-engine generators and

batteries, fuel cells are comparatively expensive. In order to be competitive, fuel cells need to

be mass produced less expensive materials developed.

An infrastructure for the mass-market availability of hydrogen, or methanol fuel

initially, must also develop. At present there is no infrastructure in place for either of these

fuels. As it is we must rely on the activities of the oil and gas companies to introduce them.Unless motorists are able to obtain fuel conveniently and affordably, a mass market for motive

applications will not develop.

At present a large portion of the investment in fuel cells and hydrogen

technology has come from auto manufacturers. However, if fuel cells prove unsuitable for

automobiles, new sources of investment for fuel cells and the hydrogen industry will be

needed.

Changes in government policy could also derail fuel cell and hydrogen

technology development. At present stringent environmental laws and regulations.

Deregulation laws in the utility industry have been a large impetus for the development ofdistributed stationary power generators. Should



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these laws change it could create adverse effects on further development.

At present platinum is a key component to fuel cells. Platinum is a scarce

naturalresource; the largest supplies to the world platinum market are from South Africa,

Russia and Canada. Shortages of platinum are not anticipated, however changes in

government policies could affect the supply.

8.2 Hydrogen in industrial uses: There are many potential uses for hydrogen in

industry, either as fuel or a chemical reducing agent if the economics were favourable. In most

of the industrial processes natural gases has been the most satisfactory source of heat, this

natural gas can be replaced by the hydrogen in these operation.

9. The advantages of hydrogen

Hydrogen resources are abundant in the Nation and the world.

Hydrogen is a component of many abundant compounds on Earth, including water,

hydrocarbons, and carbohydrates. It can be produced from a variety of resources (water,

fossil fuels, biomass) and is a byproduct of other chemical processes. All regions of the

world have hydrogen-containing resources.

Hydrogen is a domestic fuel. Every area of the country has the ability to produce

hydrogen from regional resources. Using domestic energy resources increases national

security.

Hydrogen is a clean fuel. Using hydrogen as a transportation fuel can significantly

reduce air pollution hydrogen fuel cell vehicles produce no tailpipe emissions except

heat and water. If hydrogen is produced by electrolysis using renewable energy sources,

there are no harmful emissions. Using hydrogen as a fuel can reduce greenhouse gas

emissions, especially if it is produced using renewable resources, nuclear energy, or

fossil fuels such as coal coupled with carbon sequestration (capturing the carbon-based

emissions and preventing them from entering the atmosphere).

Hydrogen is a flexible fuel. Hydrogen can be produced from a variety of resources.

Hydrogen can be produced onsite in small quantities for local use (distributed

generation) or in large quantities at production plants (centralized generation).

Hydrogen can be used as a transportation fuel for motor vehicles. It can be used topower forklifts and airport baggage trucks. Hydrogen can be used to provide electricity

and heat for buildings, and can be used in place of batteries for video cameras and

radios. Hydrogen can be used in manufacturing processes in the industrial sector.

Hydrogen can be used in fuel cells to generate electricity, with only water and heat as

by-products, and fuel cells can be used to power almost anything, from laptops to

buildings to vehicles. Hydrogen fuel cells can be used in remote places that cannot be

reached by power lines. Hydrogen, like electricity, is an efficient energy carrier,

although it is not a primary energy resource.

10.Hydrogen Safety



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Hydrogen is an energy-rich substance that must be handled properly to ensure safety.

Several properties of hydrogen make it attractive compared to other volatile fuels when it

comes to safety. Important hydrogen properties relating to safety are described below.

Hydrogen is much lighter than air and rises at a speed of almost 20 meters per secondtwo times faster than helium and six times faster than natural gas. When released,

hydrogen quickly rises and dilutes into a non-flammable concentration.

An explosion cannot occur in a tank or any contained location that contains only

hydrogen; oxygen would be needed. Hydrogen burns very quickly, sometimes making a

loud noise that can be mistaken for an explosion.

Hydrogen is odorless, colorless, and tastelessso it is undetectable by human senses.

Hydrogen equipment, and facilities where hydrogen is used, have leak detection and

ventilation systems. Natural gas is also odorless, colorless, and tasteless; industry adds

an odorant called mercaptan to natural gas so people can detect it. Odorants cannot be

used with hydrogen, however, because there is no known odorant light enough to

travel with hydrogen (remember, its the lightest element in the universe).

Although the flame itself is just as hot, a hydrogen flame produces a relatively small

amount of radiant heat compared to a hydrocarbon flame. This means that hydrogen

flames can be difficult to detect (theyre also nearly invisible in daylight) but, with less

radiant heat, the risk of sparking secondary fires is reduced with a hydrogen flame.

Any gas except oxygen can cause asphyxiation (oxygen deprivation) in high enough

concentrations. Since hydrogen is buoyant and diffuses rapidly, it is unlikely that a

situation could occur in which people were exposed to high enough concentrations of

hydrogen to become asphyxiated. Hydrogen is non-toxic and non-poisonous. It will not contaminate groundwater and a

release of hydrogen is not known to contribute to air or water pollution.

11.Hydrogen and Our Energy Future



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Hydrogen offers the promise of a clean and secure energy future, but its widespread use

by consumers nationwide will require major changes in the way we produce, deliver, store, and

use energy. Some fuel cells are commercially available today for specific applications fueling

forklifts, providing emergency back-up power, and powering some portable equipment but

there are several important technical challenges that must be solved before we see hydrogen atlocal fueling stations and fuel cell vehicles in auto dealer showrooms.

Reducing the cost of hydrogen: The cost of hydrogen, including the cost of producing and

delivering it, must be similar to or less than the cost of fuels we use today. Researchers are

working to lower the cost of production equipment and to find ways to make production

processes more efficient, which will lower the cost of hydrogen for consumers.

Reducing fuel cell cost and improving durability: Fuel cells are currently more expensive

than conventional power systems such as the engines used in cars today.

Improving hydrogen storage technology: Most of the people expect to be able to drive their

cars for long distance before refueling. Even in a highly efficient fuel cell vehicles, todays

hydrogen storage technology does not allow drivers to travel more than 300 miles before

refueling. Scientists are researching ways to improve storage technology and to identify new

ways to store hydrogen on board a vehicle to achieve more mileage.

12. CONCLUSION



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As the demand for electrical power is increasing, it becomes absolutely necessary to find

new ways of achieving the demand both responsibly and safely. In the earlier days, the limiting

factors of renewable energy have been the storage and transport of that energy. The advantage

of hydrogen storage system is the fact that the produced and stored hydrogen can be later used

in a way different from later transformation back into electricity. With the use of fuel cells andhydrogen technology, electrical power from renewable energy sources can be delivered where

and when required because of its feasibility and the energy produced from that is clean,

efficient and sustainable.

References:

1. Non Conventional energy sources, by G.D.Rai

2. Ballard Power: http://www.ballard.com/250k_stationary.asp

3. HDR Engineering and Architecture:http://www.hdrinc.com/information/search.asp.

4. S. Srinivasan, Fuel Cells from Fundamentals to Applications. New York: Springer,

2006.

5. Alternative energy - Wikipedia, the free encyclopedia.mht.

6. Fuel cell-most efficient and clean source of powerBy, R. B. Sharma and S. N. Jawarkar
http://www.ballard.com/250k_stationary.asphttp://www.hdrinc.com/information/search.asphttp://www.hdrinc.com/information/search.asphttp://www.ballard.com/250k_stationary.asphttp://www.hdrinc.com/information/search.asp

HYDROGEN as an Alternative Source of Energy

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