EMISSION REGULATION AND CONTROL SYSTEMS

1 internal combustion ENGINESINTERNAL combustion ENGINESINTERNAL combustion ENGINESINTERNAL combustion ENGINES (ELECTIVE) (ME667)(ELECTIVE) (ME667)(ELECTIVE) (ME667)(ELECTIVE) (ME667) SIXTH SEMESTER SIXTH SEMESTER SIXTH SEMESTER SIXTH SEMESTER Jagadeesha T, Assistant Professor, Department of Mechanical Engineering, Adichunchanagiri Institute of Technology, Chikmagalur EMISSION REGULATION AND CONTROL SYSTEMS There has been a great concern, in recent years, that the There has been a great concern, in recent years, that the There has been a great concern, in recent years, that the There has been a great concern, in recent years, that the I C Engines are I C Engines are I C Engines are I C Engines are responsible responsible responsible responsible for too much atmospheric pollution, which isfor too much atmospheric pollution, which isfor too much atmospheric pollution.

2 Which isfor too much atmospheric pollution, which is detrimental to human health &detrimental to human health &detrimental to human health &detrimental to human health & environment. environment. environment. environment. Thus concerted efforts are being made tThus concerted efforts are being made tThus concerted efforts are being made tThus concerted efforts are being made to reduce the responsible pollutants emitted o reduce the responsible pollutants emitted o reduce the responsible pollutants emitted o reduce the responsible pollutants emitted from the exhaust systfrom the exhaust systfrom the exhaust systfrom the exhaust system without sacrificing power &em without sacrificing power &em without sacrificing power &em without sacrificing power & fuel consumption. Air pollution can be defined as an addition to our atmosphere of any material which will Air pollution can be defined as an addition to our atmosphere of any material which will Air pollution can be defined as an addition to our atmosphere of any material which will Air pollution can be defined as an addition to our atmosphere of any material which will have a deleterious effect on life upon our planet.

3 Bhave a deleterious effect on life upon our planet. Bhave a deleterious effect on life upon our planet. Bhave a deleterious effect on life upon our planet. Besides esides esides esides ICICICIC engines other sources engines other sources engines other sources engines other sources such as electric power stations, industrial and domestic fuel consumers also add such as electric power stations, industrial and domestic fuel consumers also add such as electric power stations, industrial and domestic fuel consumers also add such as electric power stations, industrial and domestic fuel consumers also add MECHANISM OF POLLUTANTS MECHANISM OF POLLUTANTS MECHANISM OF POLLUTANTS MECHANISM OF POLLUTANTS FORMATIONFORMATIONFORMATIONFORMATION (VTU(VTU(VTU(VTU JAN 2007)JAN 2007)JAN 2007)JAN 2007) (MAIN (MAIN (MAIN (MAIN POLLUTANTSPOLLUTANTSPOLLUTANTSPOLLUTANTS EMITTED BY EMITTED BY EMITTED BY EMITTED BY PETROL ENGINEPETROL ENGINEPETROL ENGINEPETROL engine (VTU(VTU(VTU(VTU FEB 2006 FEB 2006 FEB 2006 FEB 2006)))))))) Pollutants are producedPollutants are producedPollutants are producedPollutants are produced by the incomplete burning of the airby the incomplete burning of the airby the incomplete burning of the airby the incomplete burning of the air---- fuel mixture in the fuel mixture in the fuel mixture in the fuel mixture in the combustion chamber.

4 The major pollutants emitted from the exhaust due to incomplete combustion chamber. The major pollutants emitted from the exhaust due to incomplete combustion chamber. The major pollutants emitted from the exhaust due to incomplete combustion chamber. The major pollutants emitted from the exhaust due to incomplete combustion are: combustion are: combustion are: combustion are: Carbon monoxide (CO)Carbon monoxide (CO)Carbon monoxide (CO)Carbon monoxide (CO) Hydrocarbons (HC)Hydrocarbons (HC)Hydrocarbons (HC)Hydrocarbons (HC) Oxides of nitrogen (NO).Oxides of nitrogen (NO).Oxides of nitrogen (NO).Oxides of nitrogen (NO). Other products produced are acetylOther products produced are acetylOther products produced are acetylOther products produced are acetylene, aldehydes etc. If, ene, aldehydes etc. If, ene, aldehydes etc. If, ene, aldehydes etc. If, however, combustionhowever, combustionhowever, combustionhowever, combustion is is is is completecompletecompletecomplete---- ---- the only products being expelled from the exhaust would be water vapour the only products being expelled from the exhaust would be water vapour the only products being expelled from the exhaust would be water vapour the only products being expelled from the exhaust would be water vapour which is harmless, and carbon dioxide, which is an inert gas and, as such it is not which is harmless, and carbon dioxide, which is an inert gas and, as such it is not which is harmless, and carbon dioxide, which is an inert gas and, as such it is not which is harmless, and carbon dioxide, which is an inert gas and, as such it is not directly harmful to harmful to harmful to harmful to humans.

5 CARBON MONOXCARBON MONOXCARBON MONOXCARBON MONOXIDE (CO)IDE (CO)IDE (CO)IDE (CO) : : : : It is a colourIt is a colourIt is a colourIt is a colour less gas of about the same density as gas of about the same density as gas of about the same density as gas of about the same density as air. It is a poisonous gas which, It is a poisonous gas which, It is a poisonous gas which, It is a poisonous gas which, when inhaled, replaces the oxygen in the blood stream so that the body s metabolism when inhaled, replaces the oxygen in the blood stream so that the body s metabolism when inhaled, replaces the oxygen in the blood stream so that the body s metabolism when inhaled, replaces the oxygen in the blood stream so that the body s metabolism can not function not function not function not function correctly. Small amounts of CO concentrations, when breaSmall amounts of CO concentrations, when breaSmall amounts of CO concentrations, when breaSmall amounts of CO concentrations, when breathed in, slow thed in, slow thed in, slow thed in, slow down physical and mental activity and produces headaches, while large concentration down physical and mental activity and produces headaches, while large concentration down physical and mental activity and produces headaches, while large concentration down physical and mental activity and produces headaches, while large concentration will kill.

6 internal combustion ENGINESINTERNAL combustion ENGINESINTERNAL combustion ENGINESINTERNAL combustion ENGINES (ELECTIVE) (ME667)(ELECTIVE) (ME667)(ELECTIVE) (ME667)(ELECTIVE) (ME667) SIXTH SEMESTER SIXTH SEMESTER SIXTH SEMESTER SIXTH SEMESTER Jagadeesha T, Assistant Professor, Department of Mechanical Engineering, Adichunchanagiri Institute of Technology, Chikmagalur Mechanism of formation of COMechanism of formation of COMechanism of formation of COMechanism of formation of CO CO is intermediate product of combustion remains in exhaust if the oxidation of CO to CO is intermediate product of combustion remains in exhaust if the oxidation of CO to CO is intermediate product of combustion remains in exhaust if the oxidation of CO to CO is intermediate product of combustion remains in exhaust if the oxidation of CO to C0C0C0C02222 is not complete.

7 Theoreticalis not complete. Theoreticalis not complete. Theoreticalis not complete. Theoretically , it can be said that petrol engine exhaust is free of ly , it can be said that petrol engine exhaust is free of ly , it can be said that petrol engine exhaust is free of ly , it can be said that petrol engine exhaust is free of CO if the air fuel ratio is 15. However, some CO is always present in the exhaust even CO if the air fuel ratio is 15. However, some CO is always present in the exhaust even CO if the air fuel ratio is 15. However, some CO is always present in the exhaust even CO if the air fuel ratio is 15. However, some CO is always present in the exhaust even at lean mixture and can be as high as 1%. at lean mixture and can be as high as 1%. at lean mixture and can be as high as 1%. at lean mixture and can be as high as 1%. CO is generally formed when the mixture is CO is generally formed when the mixture is CO is generally formed when the mixture is CO is generally formed when the mixture is rich in fuel .

8 The amount rich in fuel . The amount rich in fuel . The amount rich in fuel . The amount of CO formed increases the mixture becomes more and more of CO formed increases the mixture becomes more and more of CO formed increases the mixture becomes more and more of CO formed increases the mixture becomes more and more rich in fuel . A small amount of CO will come out of the exharich in fuel . A small amount of CO will come out of the exharich in fuel . A small amount of CO will come out of the exharich in fuel . A small amount of CO will come out of the exhaust ust ust ust even when the mixture even when the mixture even when the mixture even when the mixture is slightly lean in fuel . This is due to the fact that equilibrium is notis slightly lean in fuel . This is due to the fact that equilibrium is notis slightly lean in fuel . This is due to the fact that equilibrium is notis slightly lean in fuel . This is due to the fact that equilibrium is not estestestestablished ablished ablished ablished when the when the when the when the products pass toproducts pass toproducts pass toproducts pass to the exhaust.

9 At the high temperature developed during ththe exhaust. At the high temperature developed during ththe exhaust. At the high temperature developed during ththe exhaust. At the high temperature developed during the combustione combustione combustione combustion , , , , the products formed are unstable, and the following reactions take place before the the products formed are unstable, and the following reactions take place before the the products formed are unstable, and the following reactions take place before the the products formed are unstable, and the following reactions take place before the equilibrium iequilibrium iequilibrium iequilibrium is established. 2H2H2H2H2222 OOOO+ O+ O+ O+ O2 2 2 2 2(12(12(12(1----y) Hy) Hy) Hy) H22220 + 2yH0 + 2yH0 + 2yH0 + 2yH2222 + yO+ yO+ yO+ yO2222 where,where,where,where, y is the fraction y is the fraction y is the fraction y is the fraction of Hof Hof Hof H22220000 C+0C+0C+0C+02222 C0C0C0C02222 + (+ (+ (+ (1111----x)COx)COx)COx)

10 CO2222 +x CO + +x CO + +x CO + +x CO + x/2 Ox/2 Ox/2 Ox/2 O2222 As the products cool down to exhaust temperature, major part of CO reacts with oxygen As the products cool down to exhaust temperature, major part of CO reacts with oxygen As the products cool down to exhaust temperature, major part of CO reacts with oxygen As the products cool down to exhaust temperature, major part of CO reacts with oxygen form COform COform COform CO2222 However, a relatively small amount of CO will remain in exhaust, its However, a relatively small amount of CO will remain in exhaust, its However, a relatively small amount of CO will remain in exhaust, its However, a relatively small amount of CO will remain in exhaust, its concentration creasing with concentration creasing with concentration creasing with concentration creasing with rich mixtures. 2. HYDROCARBONS (HC):2.