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VEHICLE EMISSION CONTROLE BY CATLYTIC CONVERTER

Presented by:Jeevan B M

4JC15MEE112nd SEM Automotive electronics

SJCE, Mysore

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CONTENTS

• Introduction• History • Construction of catalytic converter • Working of catalytic converter• Types of catalytic converter • Advantages and disadvantages• Conclusions• References

INTRODUCTION

• Electronic emission is a substance discharged into air, especially by an internal combustion engine.

• Vehicular emissions include a number of biologically active substances such as CO, HC and NOx.

• These air pollutants are responsible for a number of adverse environmental effects such as photochemical smog, rising mercury, acid rain, death of rain forests, health hazards and reduced atmospheric visibility

• Vehicle emissions control is the study of reducing the motor vehicle emissions

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• There are mainly three types of vehicle emission control they areoAir injectionoExhaust gas recirculationoCatalytic converter

• A catalytic converter is an emissions control device that converts toxic gases and pollutants in exhaust gas to less toxic pollutants.

• A catalytic converter provides an environment for a chemical reaction wherein toxic combustion by products are converted to less-toxic substances

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Figure: location of the catalytic converter

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HISTORY

• The catalytic converter was invented by Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining.

• Houdry first developed catalytic converters for smoke stacks called “cats” for short,.

• In the mid-1950s, he began research to develop catalytic converters for gasoline engines used on cars

• Catalytic converters were further developed by a series of engineers including John J. Mooney and Carl D. Keith at the Engelhard Corporation, creating the first production catalytic converter in 1973

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• 1975 onwards started use these catalytic converters in fuel engines vehicles

• Three-way catalyst technology, introduced in the 1980s, made it also possible to control NOx emissions from SI engines

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CONSTRUCTION OF CATALYTIC CONVERTER:

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Figure: internal structure of catalytic converter

Träger-CoreZwischenschicht-Washcoat Katalysatorkontakt- Catalyst

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•The core is often a ceramic honeycomb in modern catalytic converters.

•The washcoat, when added to the core, forms a rough, irregular surface, that surface area is utilized for catalyst reaction.

•The catalyst(Platinum) itself is most often a mix of precious metals.

•Palladium(oxidation catalyst) and rhodium(reduction catalyst) are two other precious metals used.

Working of Catalytic Converter

•In chemistry, a catalyst is a substance that causes or accelerates a chemical reaction without itself being affected.

•In the catalytic converter, there are two different types of catalyst at work, a reduction catalyst and an oxidation catalyst.

•Both types consist of a ceramic structure coated with a metal.

•catalyst, usually platinum, rhodium and/or palladium.

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Figure: simple catalytic converter

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Types of Catalytic converter

•Catalytic converters are classified into 2 types based on the capability of eliminating the number of pollutantsoTwo-way catalytic converteroThree-way catalytic converter.

Two-way Catalytic converter

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• The two-way oxidation catalytic converter performs two simultaneous tasks of oxidation of carbon monoxide to carbon dioxide and oxidation of hydrocarbons to carbon dioxide and water

• Oxidation of carbon monoxide to carbon dioxide: CO + O2 → 2CO2 (carbon monoxide) (oxygen) (corban-di-oxide) • Oxidation of hydrocarbons (unburned and partially burned fuel)

to carbon dioxide and water: CₓH₂ₓ ₂ +[(3x+1)/2] O2 → xCO2 + (x+1) H2O ₊Hydrocarbon (oxygen) (carbon-di-oxide) (water) (alkane)

• Disadvantage: inability to control oxides of nitrogen

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Three-way Catalytic converter

• It converts harmful gases(Nox, co, HC) in the engine exhaust to relatively harmless gases(N2, Co2, H2O).

•A three-way catalytic converter makes use of two catalysts to convert harmful gases to harmless gases. They areoReduction Catalyst(platinum and rhodium)oOxidation Catalyst(platinum and palladium)

• Stage 1 2NO → N2 + O2(oxides of nitrogen) (nitrogen) (oxygen)

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Stage 2:in this stage oxidation occurs as in two way catalytic converter

• 3-way catalytic converters are so named because they are capable of eliminating three pollutants – NOx, CO and HC

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Pollu

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s in

gram

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Advantages and Disadvantages

• Advantageso Reduce the amount of harmful pollution produced by the

vehicleso Faster reactionso Easy replaceable

• Disadvantages:o Decreased horsepower-engine uses more energy for the

convertero Catalyst require some time to start its action

o they are very expensive to get

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CONCLUSION

•Vehicular emissions produces the CO, HC and NOx these emission are reduced by using catalytic converters.

•The two-way oxidation catalytic converter that are reduces the effect produced by CO,HC.

•The three-way oxidation catalytic converter that are reduces the effect produced by CO,HC and Nox,

•catalytic converters are play a major role in reduction of emission produced by the vehicles.

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REFERENCES

Air injection and Catalytic converters by Matthew Whitten Brookhaven College

Catalystor.pdf that gives complete information. https://www.dieselnet.com/tech/catalysts.php-gives

introduction, baground http://www.ecmaindia.in/emission-control-technology http://www.carparts.com/classroom/emission.htm-gives

the emissions control devices. http://auto.howstuffworks.com/coal-rollers3.htm-gives a

emission by vehicle Mechteacher.com-gives information about the three way

catalytic converter

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THANK YOU ALL