- The document discusses various emission control technologies used in automobiles to reduce air pollutants from vehicle exhaust. It outlines technologies like electronic fuel injection systems, multi-point fuel injection, direct injection systems, and catalytic converters. - Key pollutants of concern from vehicles include hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides. Emission standards called Bharat Stage standards are instituted in India based on European EURO standards to regulate these pollutants. - The technologies discussed aim to more efficiently and completely combust fuel to reduce emissions through things like precise fuel metering and computerized engine management. Catalytic converters also help to break down remaining pollutants in

1. EMISSION CONTROL TECHNOLOGIES
FOR AUTOMOBILES
BY
SHIRIL SAJU

2.  Emissions of many air pollutants from automobiles due to incomplete combustion of
carbonaceous fuel have been shown to have variety of negative effects on public health and the
natural environment
 Automobile emissions control covers all the technologies that are employed to reduce the air
pollution-causing emissions produced by automobiles
 Principle pollutants of concern are those through exhaust
 Hydrocarbons (HC)
 Carbon monoxide (CO)
 Nitrogen oxides (NOx)
 Particulate matter
 Sulphur oxides
 Volatile organic compounds

3. BHARAT STAGE EMISSION STANDARDS (BS)
 Emission standards are instituted by the Government of India to regulate the output of air
pollutants from automobile
 Based on European regulations (EURO)
 BS First introduced in 2000 (some other regulations were there from 1983 onwards)
PRESCRIBED EMISSION LIMITS
CO (HC + NOx) Sulphur
gm/Km gm/Km ppm
BS I 2.72 0.97
BS II 2.3 0.5 500
HC NOx
BS III 2.2 0.2 0.15 350
BS IV 1 0.1 0.08 50

4. BS vs. EURO
 BS stages are of same standards as euro stages in terms of causing pollution
 i.e. a EURO IV car makes same pollution as that of BS IV
 Differences are in terms of testing conditions
 Atmospheric temperature
Sub-zero temp in Europe and avg 24-28 degree Celsius in India
 Car speed during testing
Max 120kmph in Europe and max 90kmph in India
 Road Conditions

5.  Bharat norms are lagging behind euro norms by two stages in terms of implementation
 Higher stage means less pollution
 Meeting these regulations will need
 Latest auto-technologies
 Better Fuel quality
 New Fuel additives
lagging period

6. EMISSION CONTROL TECHNOLOGIES
• ELECTRONIC FUEL INJECTION SYSTEMS
• MULTI POINT FUEL INJECTION SYSTEM (MPFI)
• AIR ASSISTED FUEL INJECTION SYSTEM
• GASOLINE DIRECT INJECTION SYSTEM
• COMMON RAIL DIRECT INJECTION SYSTEM (CRDI)
• CATALYTIC CONVERTERS
• NANO FUEL ADDITIVES

7.  Engine efficiency has been steadily improved with improved engine design, more precise
ignition timing and electronic ignition, more precise fuel metering, and computerized engine
management.
 More efficiency => more power => less emission because of better combustion process and
efficient use of air-fuel mix
 Advances in engine and vehicle technology continually reduce the toxicity of exhaust leaving
the engine – Electronic Fuel Injection Systems
 Technologies to detoxify the exhaust are an essential part of emissions control – Catalytic
Converter
 Fuel which contains special nano particles will detoxify the exhaust without any special device-
Nano fuel additives

8. ELECTRONIC FUEL INJECTION SYSTEMS
 Inherent parts an Electronic Fuel Injection (EFI) system
 Fuel Injectors- The fuel injector sprays the appropriate amount of fuel as directed by the vehicle's
on-board computer (ECU)
 Fuel pump- The fuel pump sends the fuel from the gas tank through the fuel lines and to the
throttle body or fuel rail for delivery to the combustion chamber via the fuel injectors
 Engine Control Unit (ECU)- determines the amount of fuel needed according to the driving
conditions. The engine control unit, located within the engine compartment, follows a program
that gives the criteria for how much fuel is delivered in various situations. Programming of ECU is
basically called engine tuning.
 Sensors- Sensors located within the vehicle fuelling system help the engine control unit determine
when certain functions need to happen. Crank and Cam Position Sensor, Airflow Sensor and
Exhaust Gas Oxygen Sensor are important.

9. MULTI POINT FUEL INJECTION SYSTEM (MPFI)- for Petrol Engines
 Carburetor and SPFI was not able to deliver uniform air-fuel mixture into different cylinders
 MPFI- to supply proper ratio of air-fuel mixture to the cylinders by electrically injecting fuel in
accordance with various driving conditions
 More accurate amount of air-fuel mixture will be supplied in this injection system. As a result complete
combustion will take place. This leads to effective utilization of fuel supplied and hence low emission
level
 Fuel was delivered to outside the cylinder, just upstream of the intake valve for that cylinder
 Types of MPFI
 For all cylinders together - simultaneous
 For a group of cylinders - batched
 For each cylinder sequentially according each ones intake stroke - sequential

11. GASOLINE DIRECT IGNITION SYSTEM (GDi)- for Petrol Engines
 Direct fuel injection is a fuel-delivery technology that allows gasoline engines to burn fuel more
efficiently, resulting in more power, cleaner emissions, and increased fuel economy
 In a direct-injection system, the air and gasoline are not pre-mixed; air comes in via the intake
manifold, while the gasoline is injected directly into the cylinder
 Combined with ultra-precise computer management, direct injection allows more accurate control
over fuel metering (the amount of fuel injected) and injection timing (exactly when the fuel is
introduced into the cylinder)

12. COMMON RAIL DIRECT IGNITION SYSTEM (CRDi)- for petrol and diesel engines
 Modern variant of direct injection system- GDi uses CRDi technology- so the term more significant to
diesel engines
 Direct injection of the fuel into the cylinders of a diesel engine via a single, common line, called the
common rail which is connected to all the fuel injectors
 More accurately measured and timed mixture spray in the combustion chamber significantly reducing
unburned fuel gives CRDi the potential to meet future emission guidelines such as Euro V
 Ordinary diesel direct fuel-injection systems have to build up pressure anew for each and every
injection cycle, the new common rail (line) engines maintain constant pressure regardless of the
injection sequence. This pressure then remains permanently available throughout the fuel line.
 The engine's electronic timing regulates injection pressure according to engine speed and load
 CRDi engines are now being used in almost all Mercedes-Benz, Toyota, Hyundai, Ford and many other
diesel automobiles

14. AIR ASSISTED FUEL IGNITION SYSTEM-not very common
 Air is mixed with fuel at high pressure and is directly injected into the cylinder
 The rich mixture is injected during the suction stroke (petrol engine) or compression stroke (diesel
engine)
 The time of injection and duration of injection depends on the load, speed and other parameters and
will be as guided by ECU
 Air compressor driven by the engine is used for obtaining the pressurized air
 High pressure fuel pump is used for obtaining the pressurized fuel
 Fuel will be injected as more number of atomized particles which results in more surface area, better
combustion and less emission
SINGLE FLUID FUEL INJECTOR
AIR ASSISTED FUEL INJECTOR

15. Injection
quantity
5 mg
Single Fluid injector
30 micron SMD
471500 droplets
Total surface area : 14cm2
8 micron SMD
24,900,000 droplets
Total surface area : 50cm2
Better
atomization
Air assisted direct injector
Fuel
Economy/
Low
Emission

16. CATALYTIC CONVERTERS
 The use of catalytic converters leads to a dramatic reduction in the emissions of CO, HC and NOx
 The catalytic converter is a device fitted into the front part of the exhaust system as close as
physically possible to the engine
 It works with a combination of heat and a precious metal catalyst
 The converter is constructed of a case which houses, a normally ceramic, honeycomb monolith, the
internal surfaces of which are coated with a combination of noble metals
 Endways on this monolith is visually similar to drinking straws, with hundreds of flow channels, to
increase surface area, that allow gases to come into contact with the catalysts material
 In a catalytic converter, there are two types of catalysts at work, oxidation catalyst and reduction
catalyst

18.  Reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help
reduce the NOx emissions
 When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the
molecule and holds on to it, freeing the oxygen in the form of O2
 The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2
 2NO => N2 + O2 or 2NO2 => N2 + 2O2
 The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned
hydrocarbons and carbon monoxide by burning(oxidizing) them over a platinum and palladium
catalyst. This catalyst aids the reaction of the CO and HC with the remaining oxygen in the exhaust
gas.
 Example : 2CO + O2 => 2CO2