This document summarizes a workshop on public transport vehicles and fuels held in Bengaluru, India in 2012. The workshop discussed evaluating bus fleet options by comparing life cycle costs and emissions of different vehicle technologies and fuels. It reviewed the evolution of emission standards in India and for buses specifically. Issues around using compressed natural gas (CNG) versus diesel were discussed, with studies showing varying results. Other alternative fuels like ethanol, hydrogen fuel cells, and hybrids were also mentioned. The conclusion was that the best fuel requires life cycle analysis of costs and emissions as no single fuel is best in all respects.

1. A Workshop on Public Transport
Terminals and Support Facilities
Vehicles and Fuels
Bengaluru
February 16, 2012
Umang Jain
Associate-Urban Transport

2. Aim of the Project
 To develop a decision framework that guides the
evaluation and selection of bus fleet vehicle
technologies and fuels by comparing different
options’ life cycle costs and life cycle emissions of
greenhouse gases and air pollutants.

3. Evolution of Vehicular Emission
Norms In India
 The first Indian emission regulations were “idle emission”
limits (1989)
 Idle emission limits replaced by mass emission limits for
petrol and diesel vehicles(1991-92)
 Since year 2000,India started adopting European emission
and fuel regulations for 4 wheeled light and heavy duty
vehicles
 For 2 wheelers and 3 wheelers Indian emission
regulations apply

4. Evolution of Vehicular Emission
Norms In India
 The National Auto Fuel Policy(2003) laid down a phased program for
introduction of Euro emissions and fuel regulations as under:
Equivalent
Date of
Indian Standard European Applicable Region
Implementation
Standard
India 2000 Euro 1 2000 Nationwide
2001 NCR, Mumbai, Kolkata, Chennai
Bharat Stage II
Euro 2 April 2003 NCR, 12 Cities†
(BS II)
April 2005 Nationwide
Bharat Stage III April2005 NCR, 12 Cities†
Euro 3
(BS III) April 2010 Nationwide
Bharat Stage IV
Euro 4 April2010 NCR*, 12 Cities†
(BS IV)
† Mumbai, Kolkata, Chennai, Bengaluru, Hyderabad, 4
Ahmedabad, Pune, Surat, Kanpur, Lucknow, Sholapur, Agra

5. Evolution of Bus Emission Norms in
India
 The Emission standards for Bus engines(g/kWh) are as under:
Year Reference CO HC NOx PM
1992 - 17.3-32.6 2.7-3.7 - -
1996 - 11.20 2.40 14.4 -
2000 Euro I 4.5 1.1 8.0 0.36
2005 Euro II 4.0 1.1 7.0 0.15
2010 Euro III 2.1 0.66 5.0 0.10
5

6. Evolution of Vehicular Emission
Norms In India
 In 2007, ARAI developed emission factors for Bus (>600cc) as under:
6

7. Fuel used in Urban Buses in India
 Diesel with varying degrees of sulphur content(50-
350ppm) is used in many Indian cities
 In 1998, The Supreme Court of India passed a judgment to
convert entire bus fleet of Delhi to CNG which paved the
way for some other cities to convert to CNG as well
 There is a perception that CNG is the cleanest fuel and is
the way to go as far as fuel for public transport is
concerned
 There is not enough research into aspects of life cycle
emissions and costs of the different alternative fuels

8. Life Cycle Costs
 Capital cost of bus purchase
 Cost of modifications in depots and terminals
 Cost of infrastructure including terminals, fuelling
infrastructure
 Operation and Maintenance costs including fuel costs,
periodic and preventive maintenance, periodic bus
overhaul cost.

9. Life Cycle Emissions
 Carbon Monoxide(CO)
 Oxides of Nitrogen(NOX)
 Particulate Matter(PM)
 Hydrocarbons(HC)
 Green House gases(GHG)
 Upstream Emissions are also an important factor to consider

10. Criteria Pollutants
 CO,HC,NOX and PM are the criteria pollutants, but NOX and PM are
the most important
 NOX leads to pulmonary diseases, impairment of eyes, lungs and also
leads to acidification
 PM(<1NM) are the most dangerous as they cause maximum damage
to respiratory system

11. CNG vs Diesel
 Technical experts have estimated CNG, to be environment
friendly and cost effective.
 Critics opine that ULSD is as good in terms of emissions and
ecology and better in terms of feasibility and economics.
 While some tests have shown that ULSD, when used with
complementing engines, gives lesser emissions than CNG, others
have shown just the opposite.
In many studies vehicles of different ages, condition and
technologies have been compared leading to biased results

12. CNG vs Diesel
ARAI study concluded that:
Diesel buses fitted with advanced emission control devices and very low sulphur fuel-
emissions are comparable to Euro II CNG bus
NOX emissions from TWC equipped CNG bus are lower than DCO+CRT equipped
diesel bus, however the gap is lower for NOX than PM
12

13. CNG vs Diesel
1. ULSD is a clean fuel
 If no special measures are taken NOX emissions of CNG
are higher than diesel
 ARB study in USA proves that
CNG gives lower NOX than diesel
CNG and diesel with CRT have same PM emissions
Mutagenicity of CNG is higher
CNG gives more PM(less than 50nm)

14. CNG vs Diesel

15. CNG vs Diesel
 2.CNG emits more ultrafine particles than diesel

16. CNG vs Diesel
 3.CNG is more carcinogenic than diesel, while research proves that diesel is
fare more carcinogenic than CNG

17. CNG vs Diesel
 3.Cancer potency of CNG is 12 times more than baseline diesel

18. CNG vs Diesel
 The PM value for CNG is 5 times the value of DPF equipped diesel
 CNG also gives highest NOX values

19. CNG Vs Diesel
CNG buses produced 63&84% lower NOX and PM
emissions than diesel bus according to a study in
Washington Metropolitan Area
CNG also exhibited 9% better fuel economy than diesel
19

20. CNG Vs Diesel
20

21. CNG Vs Diesel
21

22. Conclusions on CNG vs Diesel Debate
 There are great variations in the results of different studies therefore it
is very difficult to suggest which is the better fuel
 PM emissions from CNG is low independent of technology
 CNG, depending on the technology produces from very low to very
high levels of NOX
 DPF reduces the PM emissions in diesel in some cases to below
CNG, but increases the NO2 emissions significantly
 In terms of scale of operation, a study in India estimated 8000 cum per
day of CNG needs to be sold to make operations viable.
 It is observed that Diesel can be adulterated, while CNG cannot be
adulterated

23. Other Alternate Fuels-Ethanol
 Although ethanol is a clean fuel, it is much more expensive
in terms of costs
 Based on demonstrations in SaoPaulo, the fuel related
operations cost is 20-40%higher than diesel
 The fuel economy of diesel is higher by 60%
 The maintenance costs is the same
 The costs related with ethanol are bound to come down
with increase in size of operations

24. Other Alternate Fuels-Hydrogen Fuel
Cell
Based on a study in US, there are savings of 60-80
CO2 EMT per year on 8,000 miles travelled per year

25. Other Alternate Fuels-Hybrid
According to a study based in Seattle, Hybrid performs
better in terms of all criteria pollutants
25

26. Other Alternate Fuels-Hybrid
Diesel hybrid offers:
27% higher fuel economy than diesel
4% lower maintenance cost than diesel
15% lower operation cost than diesel
26

27. Conclusion
 Decision of selection of fuel needs to be made by
conducting a life cycle emission and costs analysis of
different fuels
 Trade off needs to be made in fuel selection as no fuel is
an ideal fuel in terms of all emissions as well as costs
 Upstream emissions is an important parameter to be
included in making fuel choices
 Research and investment are needed in alternate fuels

28. EMBARQ, The WRI Center for
Sustainable Transport, catalyzes and
helps implement sustainable transport
solutions that enhance quality of life
and the environment

30. Thank you!
Global Strategic Partners
Bloomberg Philanthropies
FedEx
The British High Commission
email: ujain@embarqindia.org
web: EMBARQ.ORG
blog: THECITYFIX.COM