EXHUAST EMISSION REDUCE SYSTEM IN PETROL AND DIESEL ENGINE CAR

1. GUJARAT TECHNOLOGICAL UNIVERSITY
AHMEDABAD
Presentation on,
“EXHUAST EMISSION REDUCE SYSTEM IN
PETROL AND DIESEL ENGINE CAR”
Prepared By:
Krutik Rana(140990119048)
Active Learning Assessment(ALA)
Mechanical Engineering Department 6th sem
06/04/2017
Guided By:
Mr.Dipen A. Rana
Assistant Professor
Mechanical Engineering Department
SRICT, Vataria

2. • Exhaust Emissions are produced by cars, buses, and
motorcycles.
• Types of exhaust emissions:
 Hydrocarbons (HC)
• Resulting from the release of unburned fuel into the atmosphere.
• Produced by incomplete combustion or by fuel evaporation.
 Carbon Monoxide (CO)
• Extremely toxic emission resulting from the release of partially
burned fuel.
 Oxides of Nitrogen (NOx)
• Produced by extremely high temperatures during combustion.

3. Engine Modification Related to Emission
Control
Lower Compression Ratios
•Use of unleaded gasoline that permits use of catalytic converters and burns
completely to lower HC emissions.
•Lower combustion temperature = Lower NOx emissions.
Smaller Combustion Chamber Surface Volume
•Reduce HC emissions.
•Lowers the amount of heat dissipation out of the fuel mixture.
•Reduce the chance of fuel condensation.
Reduce Quench Areas in the Combustion Chambers
•Lower HC and CO emissions.
•Quench areas- movement of piston too close to the cylinder head.
•If too close, it tends to quench (put out) combustion and increase emissions
due to unburned fuel.

4. Emission Control System
After burner:
• An after burner is a burner where air is supplied to the exhaust
gases and mixture is burnt with the help of ignition system.
• The HC and CO which are formed in the engine combustion because
of inadequate O2 and inadequate time to burn are further brunt by
providing air separate box , known as after burner.
• The after burner is located near to the exhaust manifold with an
intention that there is no fall in the temperature of exhaust.

5. Emission Control System
• The after burner is located near to the exhaust manifold with an
intention that there is no fall in the temperature of exhaust.
• The oxidation of HC in the after burner depends upon the
temperature of exhaust.
Exhaust manifold reactor:
• It is a further development of after-burner where the design is
changed so as to minimize the heat loss and to provide sufficient
time for mixing of exhaust and secondary air.

6. Emission Control System
EXHAUST GAS RECIRCULATION ( EGR ):
• This method is commonly used to reduced NOx in petrol as well as
diesel engines.
• In S.I engines, about 10 percent recirculation reduces NOx emission
by 50 percent.
• EGR works by recirculating a portion of an engine's exhaust
gas back to the engine cylinders.

7. Emission Control System
• A portion of the exhaust gases is re-circulated to cylinder intake
charge, and this reduces the quantity of O2 available for
combustion.

8. Emission Control System
Thermal reactor system:
• A thermal reactor is a chamber which is designed to provide
adequate residence time for allowing appreciable oxidation of CO
and HC to take place.
• For enhancing the conversion of CO to CO2 the exhaust
temperature is increased by retarding the spark.

9. Emission Control System
• Actual thermal reactor that is used on a car consists of two enlarged
exhaust manifolds which allow greater residence time for burning
HC and CO with oxygen in the pumped in air.
• For keeping a flame constantly burning a secondary air pump injects
fresh air into the reactor; this reduces HC and CO.
• About 10 to 75 percent of the gas is re-circulated after cooling in
the intercooler to reduce the formation of NOx .

10. Emission Control System
Catalytic Converter system:
• The working principle of this package is to control the emission
levels of various pollutants by changing the chemical characteristics
of the exhaust gases.

11. Emission Control System
• The major advantage of this converter (as compared to thermal
reactor) is that it allows a partial decoupling of emission control
from engine operation in that the conversion efficiencies for HC and
CO are very high at normal exhaust temperatures.
• For this system, the power loss is about 30% and the fuel
consumption is about 10% more than normal.

12. Bharat stage emission standards
• Bharat stage emission standards are emission standards instituted
by the Government of India to regulate the output of air
pollutants from internal combustion engines and Spark-ignition
engines equipment, including motor vehicles. The standards and
the timeline for implementation are set by the Central Pollution
Control Board under the Ministry of Environment & Forests and
climate change.
• The standards, based on European regulations were first introduced
in 2000. Progressively stringent norms have been rolled out since
then. All new vehicles manufactured after the implementation of
the norms have to be compliant with the regulations. Since October
2010, Bharat Stage (BS) III norms have been enforced across the
country.