1. and Emissions Reduction
Engine Emissions
and
Emissions Reduction

2. Objectives You will be able to: Identify where emissions come from
Identify at least three emissions
Identify and explain the operation of an emissions reduction system
State what year Euro standards started

4. Emissions from Combustion
Nitrogen gas (N2) - Air is 78-percent nitrogen gas, and most of this passes right through the car engine.
Carbon dioxide (CO2) - This is one product of combustion. The carbon in the fuel bonds with the oxygen in the air.
Water vapour (H2O) - This is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air.

5. Carbon monoxide (CO) is a poisonous gas that is colourless and odourless.
Hydrocarbons(HC) or volatile organic compounds (VOCs) are a major component of smog produced mostly from evaporated, unburned fuel.
Nitrogen oxides (NO and NO2, together called NOx) are a contributor to smog and acid rain, which also causes irritation to human mucus membranes.

6. Particulates are soot particles caused by fuel additives
Particulates are soot particles caused by fuel additives. They are particularly prominent with diesel engines. 30% of the particles sink to the ground while the other 70% can be airborne for long periods of time
Next >

7. Euro Emission Standards
1993
Euro 1
1996
Euro 2
2000
Euro 3
2005
Euro 4
2009
Euro 5
2011
Euro 5+
2014
Euro 6-1
2017
Euro 6-2
Next >

8. Oxidization converter
Catalytic Converter
Removes harmful gases that exit exhaust.
Contains honeycomb coated with platinum and palladium (oxidation converter) and rhodium (reduction converter).
Oxidization converter changes HC and CO into H2O and CO2 (carbon dioxide).
Catalyst honeycomb
Reduction converter
Oxidization converter
Reduction converter changes NOX into N2 (nitrogen) and O2. (oxygen).
Steel shell
Inlet
Outlet
Conversion temperatures up to 900°C (1600°F).
Next >

9. Air Injection System
Forces air into exhaust ports to burn excess hydrocarbons.
Diverter valve
to air injection hose
Air injection manifold
Check valve
Air pump to diverter valve hose
Vacuum source and line
Air pump
Air pump provides a supply of pressurized air, via air injection manifold.
Diverter valve stops air flow under deceleration.
Check valve stops hot exhaust gases coming back up air hose.
Next >

10. Temperature switch (TVV)
Exhaust Gas Recirculation (EGR) System
Reduces NOX by feeding inert exhaust gases into inlet manifold, therefore lowering combustion temperature.
EGR valve can be vacuum and/or electronically controlled.
Early EGR valves operated by ported vacuum.
Exhaust gas
Inlet
manifold
EGR valve
Throttle valve
Vacuum
Temperature switch (TVV)
Ported vacuum
Exhaust gas flow
(Closed)
(Open)
Next >

11. Pressure voltage signals
Electronic EGR Components
ECU uses data from sensors to determine amount of EGR.
Metering
orifice
Exhaust gas
Inlet
manifold
Vacuum output
EVR duty cycle
control signal
Pressure voltage signals
EGR flow
Exhaust
pressure
Intake
vacuum
DPFE sensor
ECU
EVR
EGR valve
ECU operates electronic vacuum regulator (EVR) valve to control EGR valve.
Differential pressure feedback (DPFE) sensor provides feedback confirmation that EGR is operating (EOBD requirement).
Next >

12. Electronic Evaporative Emissions Control
Fuel stored in a container (fuel tank) produces vapours.
Older vehicles had vented fuel system, allowing vapours into atmosphere.
Modern vehicles have sealed fuel system.
Fuel tank is fitted with sealed cap and air dome for fuel expansion.
High pressure
release cap
Air dome
Fuel outlet
Vent line
Next >

13. Roll over valve/ vapour separator
Electronic Evaporative Emissions Control
Vent line connects to charcoal canister, via roll over/vapour separator valve.
Charcoal canister stores fuel vapours.
Purge valve controls vapour removal into inlet manifold, via purge line.
Purge valve operated by vacuum (shown) and/or ECU.
Vacuum
Fuel vapour
Air
Purge line
Fuel tank
Charcoal canister
Non-vented cap
Inlet manifold
Throttle valve
Roll over valve/ vapour separator
Purge valve
Vent line
Vacuum line
Next >

14. Positive Crankshaft Ventilation (PCV)
Combustion gases leak past piston rings, into crankcase - blowby.
Fresh air enters through the air cleaner
Vapours pass into the inlet manifold
Air flow
Blowby
Fresh air mixes with blowby gases in the crankcase
PCV valve
Older vehicles vented gases into atmosphere.
Modern vehicles use a PCV system to remove gases to be burnt in the inlet manifold.
PCV system operation is regulated by a PCV valve.
Next >

15. PCV Valve Spring loaded valve that is shut when engine is off.
At idle, maximum vacuum defeats spring pressure and minimal crankcase vapours flow.
At normal engine speeds, plunger moves to a central position and maximum vapours flow.
Spring
To manifold
Valve
Seal seat
From crankcase
= Vapour
Next >

16. Metallic substrates

17. Particulate Filters

18. Selective Catalytic Reduction

19. Objectives You will be able to: Identify where emissions come from
Identify at least three emissions

20. Objectives

21. Objectives

22. Roll over valve/ vapour separator
Objectives
Vacuum
Fuel vapour
Air
Purge line
Fuel tank
Charcoal canister
Non-vented cap
Inlet manifold
Throttle valve
Roll over valve/ vapour separator
Purge valve
Vent line
Vacuum line

23. Objectives

24. Objectives
State what year Euro standards started