Seminar report on catalytic converter

1. CATALYTIC CONVERTER
AN AIR POLLUTION CONTROL DEVICE BY MANISH CHANDRA BHARTIYA
MECHANICAL B.E
USN: 1AY13ME057
ACHARYA INSTITUTE OF TECHNOLOGY

2. INTRODUCTION
 Automobiles contribute major air quality problems in rural
as well as urban and industrialized areas
 About 72 millions vehicles produced last year (2016)
 Over 1 billion vehicles are on the roads
 Vehicular pollution is on a rampant increase

3. AIR POLLUTANTS
 All automobiles which uses gasoline, diesel and jet fuels as a source to generate power, which
emits a large amount of:
 Carbon monoxide (CO)
 Unburnt hydrocarbons (HC)
 Nitrogen oxides (NOx)
 Particulate matter (PM)

4. CAUSES OF VEHICLE POLLUTION
 The release of burnt fuel by-products and particulate matters into the atmosphere
 Evaporation of fuel
 Lack of vehicle maintenance
 Unburnt hydrocarbons

5. MEASURES TO REDUCE AIR POLLUTION
 With the modern emission standards, more advanced pollution control strategies are being
applied like:
 Modification in engine design
 Use of better quality of fuel and a sophisticated exhaust system to treat the exhaust coming out of the
engine.
 A range of secondary measures are applied nowadays, including the use of three way catalyst absorption
and filtration process

6. MODERN EMISSION NORMS
 Bharat Stage emission standards were first introduced in 2000 and since then progressively
stringent norms have rolled out
 Though implementation of mandatory catalytic converters in vehicles has started since 1995 in all
the major metro cities
 BS 3 was introduced in 2010 which is preceded by current BS 4 emission norms.

7. PATROL CAR EMISSION NORMS IN INDIA

8. CATALYTIC CONVERTER
 INTRODUCTION
 A catalytic converter is a device used to reduce the toxicity of emissions from an internal combustion
engine
 It is placed inside the tailpipe through which deadly exhaust gases containing unburnt fuel like CO, NOx
etc. are emitted
 The function of the catalytic converter is to convert these gases into CO2, water, N2 and O2

9. PLACEMENT OF CATALYTIC CONVERTER

10. TYPES OF CATALYTIC CONVERTER
THERE ARE BASICALLY 2 TYPES OF CATALYTIC CONVERTERS
 2 way catalytic converter
 3 way catalytic converter
A 2 WAY CATALYTIC CONVERTER HAS 2 TASKS:
 Oxidation of carbon monoxide to carbon dioxide:
2CO + O2 →2CO2
 Oxidation of unburnt hydrocarbons and particulate matter to carbon dioxide and water:
2CxHy + (2x+y/2)O2→2xCO2 + yH2O

11. WHILE A 3 WAY CATALYTIC CONVERTER HAS 3 TASKS:
o Reduction of nitrogen oxides to nitrogen and oxygen:
2NOx→xO2+ N2
o Oxidation of carbon monoxide to carbon dioxide:
2CO + O2→ 2CO2
o Oxidation of unburnt hydrocarbons to carbon dioxide and water:
2CxHy + (2x+y/2)O2→2xCO2 + yH2O

12. CONSTRUCTION OF CATALYTIC
CONVERTER
 The catalytic converter consists of several components:
 The core or substrate:
 A ceramic honeycomb structure or a stainless steel foil honeycomb structure are used to support the
catalyst.
 The washcoat:
 Most often a mixture of silica and alumina is used as a washcoat to make efficient use of the catalytic
converter
 A catalyst is added to the wshcoat (in suspension) before application to the core
 When added to the core, it forms a rough surface which has far greater surface area and therefore more
places for active catalytic conversion

13. WORKING OF CATALYTIC CONVERTER

14. LIMITATION OF CATALYTIC CONVERTER
 With temperatures up to 1000ª C the metal in the catalyst is prone to deactivation by sintering
 Vehicles emit most of their pollution during the first five minutes of engine operation before the
catalytic converter has warmed up sufficiently to be effective.
 Cannot function well beyond 80000 km
 It doesn’t stop the emission of CO2 and N2O, which are major greenhouse gases

15. NEW ADVANCEMENT IN CATALYTIC
CONVERTERS
 THIN WALL CERAMIC STRUCTURES
 These are extrude from dense, high strength ceramic substrate without sacrificing mechanical strength,
total surface area remains the same, back pressure reduces, conversion efficiency increases and thermal
expansion reduces.
 ELECTRICALLY HEATED CATALYST (EHC)
 The metal monolith heats the cold exhaust gases, pre converter accelerates exhaust gas conversion and
then ceramic main substrate begins conversion in less than 10 sec of the engine ignition
 PRECONVERTER
 Another option for cold start control is a small converter placed very close to the engine to accelerate
exhaust gas converter

16. ACHIEVEMENTS OF CATALYTIC CONVERTER
 Catalytic converters have also been developed for construction equipment, lawn and garden
equipment , marine engines and other non-road engines
 Catalytic converters are also used to reduce emissions from alternative fuel vehicles powered by
natural gas, methanol, ethanol and propane.
 To date more than 500 million vehicles equipped with catalytic converters have been sold
worldwide
 Worldwide over 90 percent of new cars sold had a catalytic converter

17. OVERVIEW
 Environmental, ecological and health concern resulted in stringent emission regulations for
pollution control by vehicles
 Among all the types of technologies developed so far, use of catalytic converters is the best way
to control auto exhaust emission
 Because of economical reasons, limited resources of platinum group metal and some operating
limitations of platinum group metal based catalytic converters have motivated the investigation
of alternative catalyst metertials.

18. REFERENCES
 WIKIPEDIIA
 CATALYTICCONVERTERS.COM
 WWW.CPCB.NIC.IN