This document discusses emission standards and technologies in India to reduce air pollution from vehicles. It introduces the Bharat Stage (BS) emission standards regulated by the Central Pollution Control Board. BS-III vehicles emit much higher levels of pollutants like carbon monoxide and nitrogen oxides compared to BS-IV vehicles. Selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) are technologies discussed to help meet the stricter BS-IV standards by reducing NOx emissions through the use of ammonia catalysts or recirculating a portion of exhaust gases to lower combustion temperatures. Banning older BS-III vehicles in highly polluted cities can help improve air quality and life expectancy according to statistics presented

1. Prepared By: K Mohan Reddy
15691A0393
Madanapalle Institute of Technology & Science
Mechanical Engineering

2. Introduction
 Introduced in year 2000.
 Standards are set by Central Pollution
Control Board, under ministry of
environment, forests & climate

3. Why these Standards?
 Regulate output of air pollutants from IC
& SI Engines including motor vehicles
 These norms specify the maximum
permissible emission limit for
Carbon monoxide(CO)
Hydrocarbons(HC)
Oxides of Nitrogen(NOX)
Particulate matter(PM)

4. Ban on BSIII Vechicles
 India has most polluted cities in world
 30 Indian cities figure in the top 100 most polluted
global cities in terms of PM
 As per WHO in may 2016,air pollution is the 5th
cause of death in India
 Especially in delhi vehicles emit
CO-59%
HC-50%
NOX-18%

5.  As many as 10000 people die pramaturely in delhi as a
result of air pollution
 According to one study, Delhi citizens would live an
average an extra nine years if Delhi met WHO air quality
standards.
 But, combustion inside engines not takes place 100%
due to some messy things.

6. Air Pollutants Comparison BS-III
over BS-IV
BS-III BS-IV
 Petrol Car
150 mg/km
 Diesel Car
500 mg/km
 Petrol Car
80 mg/km
 Diesel Car
250 mg/km

7. Selective Catalytic Reduction(SCR)

8. Hydrolysis Catalysis
32.5%Urea (NH2)2CO
thermally decomposes to
form ammonia and
Isocyanic acid
 (NH2)2CONH3+HNCO
 Isocyanic acid
hydrolyses to Carbon
dioxide and ammonia
HNCO+H2OCO2+NH3
Overall this is..
(NH2)2CO+H2O2NH3+CO
 Ammonia reacts with
nitrogen oxide which is
harmful to environment.
 Ammonia in the
presence of oxygen & a
catalyst will reduce
nitrogen oxides.
NOX+AmmoniaNitrogen +
water(Harmless)

9. Exhaust Gas
Recirculation(EGR)

10. Working of EGR
 5-15% air pollutants are recirculated
through EGR valve
 When fuel mixed with cool air
combustion happen little cooler.
 NOX Formation is low,actually it
creates at high temperature.
 DOC & POC

11.  DOC is designed to convert CO and HC
into CO2 & H2O
 POC removes particulate matter, HC and
CO
Hence we will get clean exhaust without NOX

12. References:-
 https://www.youtube.com/watch?v=9JtgrphwT4Q
 https://www.slideshare.net/rubel2012/selective-
catalytic-reduction-system-scr
 https://en.wikipedia.org/wiki/Selective_catalytic_re
duction

13. Thank You