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ByByKUSHAL BHATI,BH.RAJEEV VARMA,CSS.SRIDHAR.

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Why there is need of replacement?

Combustive properties of hydrogen

Is it safe?

Preparation of hydrogen fuel

Emissions

Mileage

disadvantages

• Due to excessive usage of fossil fuels, results in extinction of them.

• These fuels causes pollution to environment.

• This situation made the world automakers to search for alternative fuels that meet the requirements of present day customers.

• Also these fuels should have low emissions, high efficiency, and Cheap availability.

• Some well-known alternative fuels include hydrogen , biodiesel , methanol etc.,

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wide range of flammability

small quenching distance

High auto ignition temperature.

high flame speed at stoichiometric ratios

High diffusivity

very low density

Low ignition energy

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All fuels are hazardous, but…All fuels are hazardous, but…

Hydrogen is comparably or less so, but different:Hydrogen is comparably or less so, but different:

Clear flame can’t sear you at a distance; no smokeClear flame can’t sear you at a distance; no smoke

Hard to make explode; can’t explode in free air; burns firstHard to make explode; can’t explode in free air; burns first

Completely unrelated to hydrogen bombsCompletely unrelated to hydrogen bombs

the "forever fuel" that we can never run out ofthe "forever fuel" that we can never run out of

Water Energy Hydrogen Oxygen

Hydrogen Oxygen Water Energy

+ +

++

PREPARATION OF HYDROGEN FUEL

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Steam Reforming of Methane Steam Reforming of Methane

CH4 + H2O CO + 3H2 H298 = 206 kJ/mol

Water gas shift reaction

CO + H2O CO2 + H2 H298 = -41kJ/mol

Catalysts: Ni, or Au-Ni

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Water electrolysisWater electrolysis

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A hydrogen fuel cell engine works by mixing hydrogen and oxygen, generating electricity during the chemical reaction. Hydrogen and oxygen mix inside the fuel cell, combining to form water. This chemical reaction releases electricity, which can be stored and used to power the engine

Water is the only exhaust produced by this engine, making it a good option for reducing air pollution .

These hydrogen engines burn liquid hydrogen to move pistons and generate power. Hydrogen delivers high energy without producing harmful exhaust.

Process inside an IC Engine combustion chamber

EMISSIONS

The combustion of hydrogen with oxygen produces water as its only product:

2H2 + O2 = 2H2O

The combustion of hydrogen with air however can also produce oxides of nitrogen (NOx):

H2 + O2 + N2 = H2O + N2 + NOx

The oxides of nitrogen are created due to the high temperatures generated within the combustion chamber during combustion. This high temperature causes some of the nitrogen in the air to combine with the oxygen in the air. The amount of NOx formed depends on: • the air/fuel ratio • the engine compression ratio • the engine speed • the ignition timing • whether thermal dilution is utilized

In addition to oxides of nitrogen, traces of carbon monoxide and carbon dioxide can be present in the exhaust gas, due to seeped oil burning in the combustion chamber.

How-ever, in a gasoline engine the reduction in NOx is compromised by an increase in carbon monoxide and hydro-carbons.

MILAGE

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Hydrogen cars costs cheaper per mile when used

DISADVANTAGES OF HYDROGEN FUEL• Separation of hydrogen from other elements is expensive.

• In order to use hydrogen is converted in to liquid form , which is expensive.

• Due to its violate nature special storage tank has to be designed.

• It takes four times greater volume for storage as compared to other fuels.

CONCLUSION:

Inspite of some disadvantages there are advantages like more availability , wide range of flammability and clean burning characteristics suggests high performance in internal combustion engines . Hence we can conclude that hydrogen is an alternative fuel

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