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ALTERNATIVE AUTO FUELSCNG AND LPG 137
9
ALTERNATIVE AUTO FUELS- CNG AND LPG
Introduction
The use of gaseous fuels i.e. Compressed
Natural Gas (CNG) and Liquified
Petroleum Gas (LPG) for automotive
applications has been under taken in differentparts of the world for varying reasons. The
Committee has reviewed the global scenario,
in particular, the status of the CNG and LPG
vehicle commercialisation programmes
taken up in various countries. The Committee
has taken note of the on-going efforts for
promoting the use of these alternative fuels
in the country.
1International Association for Natural Gas Vehicles2International NGV Markets, March 2000, Dr. Jeffrey M. Seisler, Executive Director, ENGVA & President,
International Association for NGVs
International experience
Natural gas vehicles
Several countries have Natural Gas Vehicles
(NGVs). The top ten countries in terms of
NGV population are given in Table 9.1.World NGV commercialisation activities
have taken place for varying reasons in
different countries since their initial
introduction in Italy in the mid-1930s. Each
country has a different set of market
conditions, economics, gas availability /
supply, technology development, that cause
NGV commercialisation to progress at
different rates2. A brief overview of the global
NGV programmes is as follows:
Table 9.1 NGVs in the world1
Country NG vehicles Refuelling stations As on
Argentina 721830 969 November 01
Italy 380000 369 November 01
Pakistan 265000 310 June 01
Brazil 232973 284 May 02
USA 102430 1250 January 01
India 95150 124 June 02
Venezuala 40962 170 January 02
Egypt 37642 60 May 02
China 36000 70 January 01
Ukraine 31000 208 December 01
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138 AUTO FUEL POLICY REPORT
Before starting with the1984 Liquid FuelsSubstitution Programme,Argentina had a well-established natural gasconsumption culture andpipeline substructurereaching most of itspopulated cities.
Italy. Italy was the first country in the world
to use CNG as a fuel for transport in the
beginning of World War II in 1930s. This
was mainly owing to the need to become
self sufficient. War time conditions drove
Italy towards the only source of energy that
was available naturally in the country.In the 60s, petrol was easy to use, which
caused a critical situation for CNG. In the
70s, high management costs and new
technologies drove establishment of 80 new
refuelling stations connected with pipelines.
It was this development that indirectly
encouraged development of new
compression systems used for pipelines and
refuelling. Environmental awareness was not
yet widely spread even though the problem
of pollution on account of traffic had alreadybecome an issue.
Restrictions of supplies in the 70s
reduced development of network for filling
stations. The problem of supply was solved
in the mid-80s by imports from Algeria.
The key factor in the development of NG
vehicles in Italy has been the gas pipeline
network which in the 80s was extended to
obtain a backbone more than sufficient for
an efficient distribution and technology
development / export considerations. By this
time, environmental awareness began and
what had been considered a poor fuel of aself-sufficient country was now becoming a
modern environment friendly fuel. CNG
network of Italy is shown in Fig. 9.1. The
network has been developed over a period
of 70 years.
In July 2000, there were 331 filling pumps
in use. The Italians have been the historic
leaders in the NGV market, only recently
outpaced by Argentina. The Italians are
product leaders worldwide, exporting
vehicle conversion systems and compressorstation equipment to the Middle East, South
America, China, and India, to name a few.
Argentina3. Argentina had developed
additional policies of energy diversity mainly
after the Yom Kippur War (1973), taking
advantage of huge natural gas fields
discovered in the 70s. Being self sufficient
in oil and having discovered new natural gas
fields, it made sense in the 80s to aim at:
Possible expansion of CNG by replacingliquid fuels and giving place for more oil
exports and improvement of the balance
of payments.
Alternative automotive low price gas fuel
could justify taxation increases on liquid
fuels without awakening unwanted
massive protests.
Before initiating the 1984 Liquid Fuels
Substitution Program, Argentina had a well-
established natural gas consumption culture
and pipeline substructure reaching most of
its populated cities. Environmental
advantages of natural gas were known but
they did not lead the move.
3An overview of the Argentine NGV experience , Dr. Juan Carlos Fracchia, President of the Argentine
Chamber for NGV
Fig. 9.1 CNG network in Italy
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ALTERNATIVE AUTO FUELSCNG AND LPG 139
Currently Argentina has the following
infrastructure :-
11,000 km trunk lines, 43 compressor
plants (701,470 HP) plus the
compression plants of the new pipelines
to Chile.
93,000 km distribution network marking
an 83 per cent length increase since the
privatization took place in 1991. Nine NG
distribution companies covering most of
the country carry out natural gas
distribution.
Fig. 9.2 CNG network in Argentina
6 major pipeline export projects are
underway or proposed to supply outside
the country boundaries to Uruguay,
Paraguay, Chile, and Brazilian regions.
Central Chilean region is supplied as of
1997.
Ratio between reserves and productiongives 17 years for natural gas and less than
9 years for oil.
CNG network of Argentina is shown in
Fig. 9.2.
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140 AUTO FUEL POLICY REPORT
Los AngelesMetropolitanTransportation Authorityhas a fleet of above2,600 buses out ofwhich about 800 arenatural gas buses
Other European Countries: European
NGV activity outside Italy commenced after
the advent of the European Natural Gas
Vehicle Association (ENGVA) in 1994. In
other European countries like Germany,
France and U.K., though pipeline
infrastructure for gas distribution exists,NGV markets are in the initial stages of
development.
United States. NGVs had their initial start
in 1969 at the Southern California Gas
Company, which created a subsidiary to sell
NGV conversion systems. The programme
was dominated by natural gas utilities and a
small number of their customers until about
1983 when the NGV marketing effort
became more focused, expanded to fleets
of petrol vehicles using bi-fuel conversions.
Los Angeles Metropolitan Transportation
Authority has a fleet of above 2,600 buses
out of which about 800 are natural gas buses.
Japan4. The development and practical use
of Natural Gas Vehicles (NGVs) in Japan
began in the early 1990, under the initiative
of gas utilities. Most of Japans natural gas
supplies are imported as LNG. The gas price
is relatively high and so NG could not be
popularised as a cheap alternative fuel.Though Japanese NGVs are of good quality
and give high performance, they are very
expensive. Small vans and mini cars cost
about 2 times the cost of normal vehicles
4The Course of Natural Gas Vehicles Prolification in Japan and Prospects for the Next Century, Toshiharu
Sato, NGV Project Department, The Japan Gas Association, October 2000.5Natural Gas Vehicle Transit Bus Fleets : The Current International Experience by IANGV.
and a truck up to 2-ton capacity about 1.5
times their counterpart.
The Japanese natural gas industry has
been promoting NGVs, primarily in fleets.
The Japanese Government led by MITI,
MOT, and the Environment Agency has
created many subsidies for low emissionvehicles including NGV and refuelling
facilities. These subsidies were established
mainly as a result of the pressure by gas
utilities. Despite all the efforts, there are still
only a small number of NGVs and
customers, and this situation is likely to
continue for some time to come. Today there
are nearly 5250 NGVs (36 per cent owned
by gas utilities) and 107 fuelling stations (69
per cent owned by gas utilities).
China. China has NGVs supported by 70
fuelling stations. Much of the focus is on
public transport buses and taxicabs.
Principal reasons for moving to NGVs are
environmental and countrys energy security,
relying more on indigenous sources.
Natural gas for buses
While initially CNG was more popular for
use in cars, many cities have inducted CNG
buses for city operations. The number ofCNG buses in the major cities of the world
in year 2000 are given in Table 9.25.
As per the information available, South
Korea and China have plans to induct quite
Table 9.2 CNG city buses in different countries
Country / City Total buses CNG buses % of CNG buses
USA
Dallas 810 22 2.7
Los Angeles 2,638 795 30.1New York 5,675 358 6.3
New Jersey 3,094 55 1.8
Canada
Toronto 1,500 125 8.3
Vancouver 1,006 51 5.1
(contd)
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ALTERNATIVE AUTO FUELSCNG AND LPG 141
6Urban Transportation Bureau of Shanghai Municipality and Indian Embassy at Beijing.7Department of Air Preservation, Seoul Metropolitan Government.8In addition to above about 2800 RTVs (mini buses) ply in the city of Delhi.
Table 9.2(contd.)
Country / City Total buses CNG buses % of CNG buses
Germany
Berlin 1,700 10 0.6
France
Paris 4,000 53 1.3
Italy
Rome 2,383 40 1.7
Spain
Barcelona 800 2 0.3
Madrid 1,000 15 1.5
Greece
Athens 1,500 40 2.7
Australia
Sydney 3,900 254 6.5
Brisbane 1,100 12 1.1Perth 850 52 6.1
Melbourne 1,400 24 1.7
China (May 2002)6
Shanghai 18500 330 1.8
Beijing 10000 1640 16.4
South Korea (May 2002)7
Seoul 8200 880 10.7
India (June 2002)
Delhi 12000 61758 51.5
a large number of CNG buses in their city
bus fleets. Their plans are as follows:
China6: Out of the 18,500 buses in
Shanghai, 300 buses use CNG, About
11,250 buses run on diesel and the balance
run on petrol. It is planned that by the end
of 2003, CNG buses will be increased to
500; by the end of 2005, another 2,870
CNG buses will be added. The CNG buses
may gradually be increased to 20 30 percent of the total fleet, the remaining being
diesel buses complying to Euro II emission
standards. In Beijing, 1,640 buses out of a
total of 10,000 buses run on CNG.
However, there are no plans to phase out
diesel buses. Possibilities for introducing
LPG buses and fuel cell buses in future are
being examined.
South Korea: Koreas Ministry of
Environment has initiated a programme to
replace all the diesel-powered transit bus
fleet with compressed natural gas (CNG)
buses, starting in the year 2000. Targeted
for replacement in Koreas 9 major citiesover the next seven years are up to 20
thousand buses. The CNG bus programme,
is facilitated by many factors, some of which
are:
In Beijing, 1,640 busesout of a total of 10,000buses run on CNG.
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142 AUTO FUEL POLICY REPORT
1. Korea is a small country having an
area of about 99,300 square
kilometers but relatively large
coastline of about 2,400 kilometers
(India is about 32,88,000 sq.
kilometers with a coastline of about
7,000 kilometers). A nationwidenatural gas pipeline infrastructure
was constructed in mid 1990s. The
countrys smaller area having a
large coastline and an existing
nationwide natural gas pipeline
infrastructure to support gas sales
have made conditions favourable
enough for setting up the CNG
infrastructure.
2. An existing city gas pipeline
network, laid for domestic andcommercial gas supplies, reduces
*First Quarter 2002
Souece : Cedigez 2000 survey : US, DOE webside
the gas distribution costs within the
city. Thus construction of CNG
refueling stations at bus terminals
could be done at lower cost.
3. A well-established LNG import
infrastructure (2 LNG terminals
exist with import capacity of over
16 million metric tonnes of LNG per
annum, the third one is expected to
be operational in November 2002)
coupled with the gas pipeline grid
ensures security of supplies. LNG
is imported by South Korea from a
diversified set of exporters. Imports
are mainly from Indonesia,
Malaysia, Brunei, Qatar, Oman and
UAE. In the event of supply
disruption at any import location,supplies can be substituted from
another location.
Natural gas consumption pattern in
different countries
Natural gas and its propensity of use in an
economy are indirectly related to the
development of NGVs. Natural gas
consumption by sector in the above
mentioned countries is shown in Table9.3.
Table 9.3 Gas consumption by sector in select countries in 1999
Country Power/Industrial % Commercial/
Residential/Others %
Italy 58.6 41.3
Argentina 64.0 36.0
Pakistan (1998) 76.1 23.9
USA 55.9 44.1
India* 97.0 3.0South Korea 52.4 47.6
Venezuela 40.0 60.0
Egypt 85.2 14.8
China 89.0 11.0
Conclusions
The review of NGVs programmes in
different countries reveals that NGVs have
been commercially successful proposition in
countries which have adequate indigenous
resources of natural gas, a well developed
gas grid, and a long established usage of gas
as domestic/commercial fuel.
NGVs have also been successful in
countries which do not have enough
The review of NGVsprogrammes in differentcountries reveals thatNGVs have beencommercially successfulproposition in countrieswhich have adequateindigenous resourcesof natural gas, a welldeveloped gas grid,and a long establishedusage of gas as
domestic/commercialfuel.
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ALTERNATIVE AUTO FUELSCNG AND LPG 143
In India, having regard tothe countrys vastness,natural gas vehicles canbe commercially viableonly in the cities, wherenatural gas pipelinesexist or would be laid infuture.
indigenous gas production to meet the
domestic demand but have access to gas
from neighbouring countries, along with a
well-knit gas pipeline network set up either
for historical reasons, or to meet cold climate
requirements for heating and cooking
purposes .In contrast, where an elaborate pipeline
grid does not exist, NG economics becomes
unfavourable and promoting NGVs is
tough, despite subsidies.
In India, having regard to the countrys
vastness, natural gas vehicles can be
commercially viable only in the cities where
natural gas pipelines exist or would be laid
in future. Cost of establishing fresh gas grids
are quite high and for that reason alone it
may not be feasible to dispense CNG for
automotive purposes in most cities in the
near future.
LPG vehicles
The total number of vehicles in the world
operating on LPG was around 5.6 million
in year 1999. The major countries using
LPG as an automotive fuel are Italy,
Netherlands, Poland, USA, Canada,
Mexico, Australia, New Zealand, Algeria,
Turkey, Iran, South Korea, and Japan. Of
these countries, the largest number of LPG
vehicles, over 1.2 million, are in Italy. China
is one of the recent entrants in this area with
around 50,000 vehicles in the year 1999.9
Europe: In Europe, supply of LPG comes
from many sources. More than half (60 per
cent) of LPG is produced by separation from
oil and natural gas fields, the balance coming
from refining of crude oil. Europe has access
to three major supply sourcesthe NorthSea, Algeria, and the former Soviet Union
countries.
In Europe, natural gas is one of the
primary sources of domestic heating and
cooking. Countries which use NG for
residential heating and domestic cooking
tend to have lower LPG demand for these
purposes. For example, 38 per cent of
NG in Italy is consumed by the commercial
and residential sector. Domestically
produced LPG then becomes available for
use as auto fuel.
USA & Japan: In USA and Japan whichby the early nineties had 2,66,000 and
3,00,000 LPG vehicles, no growth in the
LPG vehicles took place in the nineties. In
these countries the number of LPG vehicles
over past 10 years has stagnated/ reduced,
number of LPG vehicles as percentage of
the total vehicles having reduced in both
cases.
South Korea: South Korea, a net importer
of LPG but having high LPG vehicle
population, has a different history, where
large scale conversions from petrol vehicles
to LPG have taken place not due to a
planned effort but on account of pricing
advantage that the vehicle owners found in
using LPG as an automotive fuel. The LPG
history of South Korea is that due to strong
market intervention by the Government, the
Korean energy market has had a highly
distorted pricing system. The market
distortion has taken place through different
tax rates, financial supports, and price
regulations. In 1983, in order to respond to
a strong request for market liberalization, the
Korean Government started taking steps to
reduce its intervention in petroleum market.
Several steps were taken one by one until
the prices of petroleum products except LPG
were completely deregulated in 1997. The
prices of petroleum products are subject to
several taxes to raise revenue for
Government expenditure. Petrol is heavily
taxed compared to other products.
An LPG crisis resulted from the distorted
relative prices of transportation fuels. The
relative prices of petrol, diesel and
automotive LPG were 100:47:26 till the year
2000. Because of relatively low LPG price
913th World LPG Forum, October 2000, San Diego, California.
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144 AUTO FUEL POLICY REPORT
and various tax benefits for mini vans, LPG-
fueled vehicles rapidly increased. This
resulted in the decreasing tax revenues and
the need to increase the number of LPG
recharge stations. The annual increase in
rate of LPG vehicles was about 60 per cent
in 1999. Therefore, the Government hikedthe special excise tax on butane in July 2001
with the intention to correct disparity in fuel
prices.
A review of the countries using LPG as
alternative fuel reveals that the driving force
behind the LPG vehicle commercialization,
except in the case of South Korea, has been
easy availability of LPG either within the
country or from a major export market
located next door along with natural gas
being an established domestic fuel. Asbrought out in Chapter 13 of the Report,
LPG costs less where it is produced, but
becomes substantially costlier than liquid
auto fuels when it is required to be
transported over long distances, overseas
or inland, requiring high cost storage and
transportation infrastructure. For this reason,
in countries that are net exporters of the
product or are located in the close vicinity
of major export markets, cost effectiveness
of LPG makes it a normal fuel rather than
an alternative fuel. Practically all countries,
except South Korea, where LPG has been
successfully commercialized for automotive
use, are either major producers/ net
exporters of LPG or located close to the
countries that are net exporters of the
product as below:
Countries like Canada, Australia, New
Zealand, Former Soviet Union countries,
Iran , Algeria etc are net exporters ofLPG. Being competitive with petrol,
LPG for automotive purposes is used as
a normal fuel in these countries.
Italy, Turkey, Netherlands, and Poland
are located in the vicinity of major LPG
producers/exporting countries. In these
countries also LPG being competitive with
auto fuels, using LPG as auto fuel is cost
effective.
In USA and Japan the number of LPG
vehicles has not grown over the past ten
years and in South Korea, use of
imported LPG by a large number of
vehicles affected Government revenuesand put pressure on infrastructure.
Conclusions
LPG is commercially viable as a normal auto
fuel in countries that are exporters of LPG
or have access to low cost LPG supplies
from their neighbour exporting countries.
In countries, where NG is used for
domestic heating and cooking, the next cost
effective use of domestically produced LPGis in automotive applications rather than for
exports. This results into usage of LPG for
automotive applications.
In India, LPG is the main domestic fuel in
urban areas. The indigenous availability of
LPG is expected to fall much short of the
household demand alone. As such none of
the above mentioned conditions which
made LPG as a competitive auto fuel in other
countries, exist. For these reasons, as
brought out in Chapter 13, LPG to becompetitive as an auto fuel, in India would
need Government support by way of
substantially lower taxation.
Gaseous fuels (CNG & LPG)
technology and emissions
Passenger cars
Most of the gaseous fueled passenger car
engines are the petrol engines retrofitted withCNG / LPG kits. Earlier, cars were fitted
with simple carburetor system for inducting
gaseous fuel such as CNG or LPG and was
designated as first generation kit.
Subsequently, in order to make the engine
operate on stoichiometric air fuel ratio, this
design was modified and kit was classified
LPG costs less where itis produced, butbecomes substantiallycostlier than liquid autofuels when it is requiredto be transported overlong distances,overseas or inland,requiring high coststorage andtransportationinfrastructure.
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ALTERNATIVE AUTO FUELSCNG AND LPG 145
Introduction of advanceddesign petrol cars in therecent years withsubstantially loweremission levels havecreated new comparisonlevels between the petroland gaseous fuels.
as second generation kit. For meeting the
stringent emission norms, further
improvements were made in the kits by
incorporating multi-point fuel injection
system and the kit designated as third
generation kit. In the 70s and early 80s,
gaseous fuel cars had substantially lowerexhaust emission levels than the gasoline cars
of that time. However, the introduction of
advanced design petrol cars in the recent
years with substantially lower emission levels
created new comparison levels between the
petrol and gaseous fuels.
The CO emission and NOxemission for
vehicles running on petrol and LPG over
time are shown in Charts 9.1 & 9.210.
10Technical reference paper by Bas Hollemans, TNO Road Vehicles Research Institute, The Netherlands.
NOx
emission (g/km)
Chart 9.1
CO emission (g/km)
Chart 9.2
In the early seventies emission legislation
was not as stringent as at present. Then it
was easy to meet the emission standards on
LPG as petrol emissions were much higher
at that time, and LPG helped in reducing
emissions substantially.
The introduction of passenger cars
equipped with a lambda controlled three-
way catalyst changed the situation
completely. The equipment manufacturers
did not anticipate these new petrol
technologies and LPG gave no advantage
when used with the three way catalyst.
Consequently, emission results of 1988,
shown in the same charts for petrol and LPGshow an advantage for petrol.
Subsequently, several LPG kit
manufacturers started developing Lambda
controlled fuel systems for LPG which
enabled the LPG vehicles to comply with
the same emission standards as for petrol
vehicles.
In order to estimate the impact of fitment
of LPG kits on the emissions of in-use cars,
the Committee looked at the international
experience. The emission results observed
during a study conducted by South West
Research Institute (SAE paper 932745) on
a 1992 Chevrolet Lumina car, with petrol
and with 3 different LPG conversion kits are
given in Table 9.5.
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146 AUTO FUEL POLICY REPORT
11SAE paper 932745 based on a South West Research Institute Study.12IANGV report dated 31.3.2000.
Results show thatdifferent LPG kitscould result indifferent emissionvalues from thesame car.
The above results show that different LPG
kits could result in different emission values
from the same car. However, it was seen in
this study that the NOxemission increased
with all kits and in case where the CO
emissions were significantly lower, the NOx
emissions increased substantially.
The emissions data as reported in anIANGV report of March, 2000, comparing
emissions with petrol, LPG and CNG fuels
on a new technology, category 2 vehicle
while using the state-of-art conversion kits
are given in Table 9.612.
Table 9.6 Emission results on a three way catalyst fitted vehicle12
Emissions, g/km Petrol LPG CNG
Carbon monoxide 1.12 0.91 0.45
Hydrocarbon 0.15 0.12 0.36
Nitrogen oxides 0.15 0.21 0.13
Particulates 0.015 0.005 0.025
The above data shows that in the new
generation cars there may be some
improvement in emissions of carbon
monoxide by changing over to gaseous fuelsbut there is no particular trend with regard
to other pollutants. As compared to petrol,
LPG showed higher NOx
while use of CNG
showed marginally higher particulates. This
implies that in new technology cars, there
may not be any significant change in the
overall emissions, some pollutants may
decrease while others may increase by
change over to gaseous fuels. Unlike diesel
vehicles, the use of gaseous fuels in place of
petrol in passenger cars does not result in
any significant advantage in terms of
particulate emissions for the reason that in
both cases, particulate emissions are verylow.
The World Bank, in a briefing note on
international experience with CNG vehicles
prepared in October, 2001, as part of the
South Asia Programme on urban air quality
management, funded in part by the joint
UNDP/World Bank Energy Sector
Management Assistance Programme
(ESMAP), observed the following:
With respect to emissions, it is worth
noting that advanced technology gasoline
vehicles with three-way catalysts are so
clean that the fuel itself (that is, whether
liquid or gas) plays a relatively minor role,
Table 9.5 Emission results with different LPG conversion kits11
Fuel CO g/km HC g/km NOxg/km
Petrol 5.40 0.37 0.42
LPG kit 1 1.90 0.33 1.62
LPG kit 2 10.23 0.57 0.57
LPG kit 3 2.55 0.21 0.67
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ALTERNATIVE AUTO FUELSCNG AND LPG 147
especially for the regulated emissions.
Under these circumstances, converting
an advanced petrol vehicle to gaseous
fuel could even increase, rather than
decrease, emissions.
Two/three wheelers
Earlier the two and three wheelers operating
in India were mostly powered by 2 stroke
petrol engines. The inherent design of the 2
stroke engine is responsible for higher
hydrocarbon emissions. Further, the
combustion of lubricant along with the fuel
is responsible for particulate emissions from
such vehicles. However, their NOxemissions
are lower.
In a study conducted by South WestResearch Institute(SWRI), USA related to
the exhaust emissions from small 2 stroke
(28 cm3 capacity engine) and small 4 stroke
(148 cm3 capacity engine) operating on
petrol and LPG, presented in the Small
Engine Technology Conference (SETC)
organized by SAE International in Italy in
December, 1993 (SAE paper no. 931540)
mass emissions from small engines were
shown as given in Table 9.7.
It is seen from Table 9.7 that particulates
from 2-stroke engines are high irrespective
of the fuel used on account of the
combustion of lubricant along with the fuel.
However, the emissions of oxides of nitrogen
and carbon monoxide are seen to be higher
in the case of 4 stroke engines irrespective
of the fuel used.
Table 9.7 Mass emissions from small engines (g/kwh)
Pollutants 2-Stroke 4-Stroke
petrol LPG petrol LPG
CO 300 349 672 558
THC 112 107 57.9 61.4
NOx
1.05 0.65 2.74 1.39
PM 4.33 4.30 0.67 0.51
Since the particulates emanate on account
of the combustion of lubricant in 2 stroke
engines, the quality and quantity of lubricant
used needs to be controlled. This could be
achieved by switching over to dispensing of
pre-mixed petrol to 2 stroke vehicles in
major cities. When manufacturersinstructions in regard to use of lubricants are
followed, excessive particulates from 2
wheelers should not be a problem. As long
as they meet the prescribed emission norms,
both technologies should be acceptable.
Buses
At present, there is no gas engine that has
the same kind of power output, fuel economy
and reliability as that of a modern diesel
engine. Therefore, the gas engines for busapplication are mostly based on converted
diesel engines. The conversion to gaseous
fuel engines (CNG or LPG) for heavy duty
application involves changeover to Spark
Ignition (SI) operation. The engine
manufacturers use either stoicheometric or
lean burn combustion. It is reported by
IANGV that from engine durability point of
view, lean burn combustion is generally a
preferred alternative where as stoicheo-
metric application in combination withcatalytic converter gives lower emissions and
better driveability.
For in use diesel buses, the conversion
techniques presently being used in India are
not proven technologies. For conversion, the
existing diesel engine is modified to run on
CNG by replacing piston, cylinder head,
cooling system, intake manifold and
At present, there isno gas engine thathas the same kind ofpower output, fueleconomy and reliabilityas that of a moderndiesel engine.
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148 AUTO FUEL POLICY REPORT
incorporation of ignition system and
converting into SI engine. It is not a reliable
system and there are complaints of engine
overheating, spark plug fouling, engine head
leaking, etc. The OEM CNG engines in India
are also not original gas engines, but
converted from diesel engines using thediesel engine block. Hence, they would have
the same problems as converted vehicles
including the engine overheating problem.
A diesel engine converted to a CNG
engine has different speed-torque
characteristics, which leads to the problem
of failure of clutch plate, over heating, loss
in power etc. The fitment of cylinders and
high-pressure fuel-line on in-use vehicles
require high quality fittings, which should
withstand the chassis vibrations on Indianroads. More experience and continuous
improvements would lead to improved
levels of technology in this area.
The main problem reported with gas
engines is the control of thermal loads of
the engine and control of NOxemissions.
A gas engine, which is not emission
optimized can have much higher NOx
emissions than diesel engine.
In Europe, there has been much
discussion on the real life emission
performance of buses operating on NG.
Although some of these bus engines give
very good emission in steady state testing
as is done in type approvals, they do not
appear to perform well in real life transient
conditions.
In a recent report13 of August 2001, the
following has been reported:
CNG vehicle for one mile emits 20 per
cent more greenhouse gases than drivinga comparable diesel vehicle for one mile.
From the perspective of global warming,
the decision to switch from diesel to CNG
is a harmful one. CNG vehicle emits 80
per cent less particulate matter, 25 per
cent less nitrous oxides, and 35 per cent
less hydrocarbons (volatile organic
compounds). However, the output of
carbon monoxide is over five times
greater than for diesel.
The emission results from aEuro IIdiesel
bus and CNG bus manufactured by anOriginal Equipment Manufacturer (OEM) in
India are given in Table 9.8. It can be seen
that CNG has a clear advantage in terms of
particulates and oxides of nitrogen but the
carbon monoxide and hydrocarbon
emissions are higher. It is noted that data
are without catalytic converter for a diesel
bus, and with a catalytic converter for CNG,
which on deterioration over a period of time
may result into much higher CO and HC
emissions.
The type approval data of the CNG and
diesel buses given in Table 9.9, indicates
that CNG has an advantage for particulate
emissions, but the CO emissions with
CNG are more than twice of that of
Bharat Stage IIdiesel engine.
The type approval data of the converted
engines of model 1992 to 2000, given in
Table 9.10 indicates both the carbon
monoxide emissions and hydrocarbons andoxides of nitrogen are higher from the
converted CNG engines as compared to
Bharat Stage IIdiesel engines.
Central Road Research Institute (CRRI)
conducted tests of carbon monoxide
emission from few randomly selected CNG
buses operating in Delhi. The buses were
tested for carbon monoxide at idling and
during driving (i.e. average of 30, 40 and
50 km/hour). The data generated by CRRI
in the laboratories of IOC R&D is given inTable 9.11. The tests show that carbon
monoxide emissions vary from one bus to
another and that carbon monoxide
emissions increase with the age of CNG
vehicle.
CNG has advantage forparticulate emissionsbut the carbon monoxideemissions with CNGare more than twicethat of Bharat Stage IIdiesel engine
13Report on A Fresh Look at CNG : A Comparison of Alternative Fuels, August, 2001 Authored by the
Alternative Fuel Vehicle Programme sponsored by HGCI, UOS, Ford Motor Company, and Harvard University.
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ALTERNATIVE AUTO FUELSCNG AND LPG 149
Table 9.8 OEM bus emission data with Bharat Stage II diesel engine and CNG engine14
Emissions, g/kWh Diesel (Bharat Stage II, CNG
without catalytic converter) (with catalytic converter)
Carbon monoxide 1.06 1.68
Hydrocarbons 0.36 1.64
Nitrogen oxides 5.89 3.42
Particulates 0.113 0.03
Table 9.9 Type approval emissions data of CNG and diesel buses15
(A) Engines CNG (Bharat Stage II)
Mass Emissions in g/kWh
Manufacturer/ CO THC NMHC NOx
Model
OEM1/1 2.69 1.22 0.028 1.32
OEM1/2 0.46 0.91 0.03 3.39
OEM1/3 2.28 1.96 0.12 3.03
OEM1/4 2.95 0.27 0.017 1.52
OEM1/5 0.08 0.49 0.029 3.08
OEM2/1 2.50 0.71 0.020 1.94
OEM3/1 2.92 1.30 0.04 2.91
OEM3/2 0.41 0.81 0.037 8.12
OEM4/1 1.69 0.28 0.013 0.03
Average 1.77 0.88 0.037 2.81
(B) Engines Diesel (Bharat Stage II)
Manufacturer/ CO HC NOx
PM
Model
OEM1/6 1.06 0.36 5.89 0.113
OEM1/7 0.75 0.22 8.23 0.105
OEM1/8 1.21 0.23 6.60 0.102
OEM1/9 0.57 0.16 5.67 0.115
OEM1/10 0.48 0.16 5.30 0.122
OEM3/3 0.84 0.24 6.27 0.127
OEM3/4 0.66 0.30 6.13 0.118
OEM4/2 0.81 0.23 8.89 0.116
Average 0.80 0.24 6.62 0.115
14Presentation of a vehicle manufacturer to Expert Committee.15Type approval data of ARAI, IIP etc.
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150 AUTO FUEL POLICY REPORT
Table 9.10 Type approval mass emission data of CNG converted engines15
MFR/Model Year ENGINE CO THC NMHC NOx
of Mfg CAP. Ltr. gm/kWh gm/kWh gm/kWh gm/kWh
OEM1/11 1993 5.721 1.8 3.04 0.41 5.9
OEM1/12 1993 5.721 2.5 3.08 0.41 5.1
OEM1/13 1996 5.675 0.4 2.97 0.50 10.8
OEM1/14 1996 5.675 5.5 1.37 0.18 14.1
OEM3/5 2000 6.014 1.3 2.60 0.35 5.8
OEM3/6 1992 6.075 9.3 5.09 0.70 12
AVERAGE - 3.47 3.03 0.43 8.95
Table 9.11 CO emission data generated by CRRI on randomly selected CNG buses
Bus description CO during idling CO during driving on
chasis dynometer
(average 30, 40, 50 kph)
CNG (OEM1/15) after 11000 kms 0.07% 0.01%
CNG (OEM 1/16) after 42600 kms 0.38% 0.74%
CNG (OEM 3/7) after 11500 kms 3.42% 1.01%
CNG (OEM 3/8) after 51000 kms 5.12% 1.16%
CNG (Retrofit 1/1) 3700 kms 0.10% 2.87%
CNG (Retrofit 1/2) 23000 kms 0.30% 5.63%
In the case of alternativefuels CNG and LPG, toachieve the intendedbenefits with respect toemissions, maintainingthe quality of conversionkits is crucial.
Field performance of different
fuel technology vehicles
In India, on account of differentials in theprices of transportation fuels and other fuels,
at times, adulteration of auto fuels carrying
higher prices with low priced industrial fuels
is resorted to. Depending on as to which
other fuel is mixed with the transportation
fuel, some deterioration in emission
performance of vehicles would take place,
particularly when the quantity of the other
fuel mixed with the transportation fuel is
substantial.
In the case of alternative fuels CNG andLPG, to achieve the intended benefits with
respect to emissions, maintaining the quality
of conversion kits is crucial. That exhaust
emissions from vehicles converted to CNG/
LPG could substantially vary depending on
the quality of kit used is evident from the
preceding Table 9.5, Table 9.9 and
Table9.10. The variation in performance
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ALTERNATIVE AUTO FUELSCNG AND LPG 151
of different kits even at the type approval
stage is too marked. The Committee is
aware of the fact that there is an unauthorized
conversion of petrol vehicles to LPG mode
using the kits that do not have type
approvals, and that these are marketed at
prices substantially lower than the prices ofthe standard conversion kits. Most
workshops, currently undertaking
retrofitments do not have necessary
permissions/approvals. The common
perception that conversion of an engine from
liquid auto fuels to gaseous auto fuels
irrespective of the kit technology, brings
about all-round emission improvements, is
really not true. The issues of availability of
unauthorized substandard kits in the market
and their use in vehicles and conversion beingundertaken by unauthorized workshops are
no less important issues from the angle of
pollution from auto exhausts than the issue
of adulteration in liquid auto fuels. As may
be seen from Table 9.11, in the absence of
proper upkeep and maintenance of kits in
alternative fuel vehicles, deterioration in
emission factors may be considerable.
The Delhi Transport Corporation (DTC)
in the month of November, 2001 shared
with the Committee their experience ofrunning a 1700 CNG bus fleet which is
summarized in Table 9.12.
I&M mechanismsto check quality ofalternative fuel kitsand their on-roadperformance arenot yet in place tothe required level.
Table 9.12 Field performance of DTC CNG buses
Performance parameter Experience
Fuel efficiency 3.32 km/kg with CNG against 4.46 km/kg
(3.75 km/ltr.) with diesel
Operational performance Power loss, gas leakage, starting trouble, engine over
heating cylinder head failures, spark plug problems
and frequent breakage of silencer muffler.
The Committee is informed that I&M
mechanisms, to be set up/implemented by
the state Governments, to check quality of
alternative fuel kits and their on-road
performance, particularly for the converted/
retrofitted vehicles owned by individual
transporters, are not yet in place to the
required level. The position obtaining
presently appears to be that whereas
mechanisms, though not foolproof, exist and
more are planned to be put in place to check
adulteration in liquid auto fuels, thereappears to be even lack of awareness among
the vehicle owners and the public about the
need/importance of the use of the right quality
kits and the potential deterioration in
emission factors which the use of
substandard kits may lead to. The testing
facility for checking the quality of kits exists
only at 3-4 places in the country. In the case
of alternative vehicle conversion kits,
guidelines for the authorized testing agencies
are in place. However, after a kit design hasbeen type approved, the systems for regular
checking of the quality of kits actually being
used for conversion/retrofitment appear to
be weak. The Committee was informed that
proposals for third party inspections are
under consideration by the Government of
the NCT of Delhi. Realising that the number
of vehicles is many times more than the
number of fuel dispensing stations, ensuring
the use of the right quality conversion kits is
an area as difficult to be tackled as checkingadulteration. However, as both are crucial,
they need to be attended to on priority or
else the expected benefits from the use of
cleaner fuels, involving substantial additional
costs, may not be achieved. As imple-
mentation of motor vehicles regulations in
the field falls within the purview of the
Note: CNG engines being used for buses in India are basically the diesel engines modified to operate on CNG
and are design wise expected to result in power lose, engine over heating etc. The field experience of DTC
with CNG buses confirms the same.
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152 AUTO FUEL POLICY REPORT
New generation enginetechnologies for carsand three-wheelers usingeither liquid or gaseousfuels have resulted inreducing pollution fromauto exhaust. Gaseousfuels have an advantageover liquid fuels inrespect of some of theemission parameters,whereas liquid fuels
have advantage inrespect of others.
states, a lot of effort would need to be put
by them and their active involvement for
putting in place the requisite I&M system is
considered extremely necessary.
Energy efficiency of gaseous fueled
engines
The maximum efficiency of spark ignited
gas engine is some 10 15 per cent lower
(relative) than that of a good diesel engine.
In real service, the energy consumption
difference is higher; both due to reduced
efficiency at partial loads, and increased
vehicle weight12. IVECO estimated that a
CNG bus, which weighs some 700 kg more
than its Euro IIIdiesel counterpart,
consumes 25 per cent more energy. TNOs
also has made similar estimation on energy
efficiency of different bus technologies as
given in Table 9.13.
Competition to gaseous fuel
technologies from emerging
diesel technologies
The future diesel engines, running on high
quality diesel fuel and equipped with De-
NOxsystems and / or particulate traps, will
be very clean. The Original EquipmentManufacturers (OEMs) views differ on the
future of competitiveness of gas engines, as
some say that the gas engines will become
less attractive as the diesel becomes cleaner,
while others think that the gas engines will
have a good chance as the emission
regulations are becoming more stringent. The
challenge for diesel engines would be
cleanliness and for the gas engines, fuel
efficiency.
ConclusionsMotor vehicles
technologies & emission benefits
The Committee reviewed the conventional
fuel and CNG/LPG technologies and their
relative benefits in terms of auto exhaust
emissions for new vehicles and for converted
old vehicles. The main conclusions are:
For New Vehicles:
(a) New generation engine technologies for
cars and three-wheelers using either
liquid or gaseous fuels have resulted in
reducing pollution from auto exhaust.
Gaseous fuels have an advantage overliquid fuels in respect of some of the
emission parameters, whereas liquid
fuels have advantage in respect of
others.
(b) Engines for buses, designed and
manufactured for operation on CNG,
offer benefits in terms of lower oxides
of nitrogen and particulate matter. CO
emissions from CNG engines are,
however, higher as compared to the
emissions from diesel engines. The
particular matter emission benefits
derived fromEuro IIand higher diesel
technology buses are as high as 85 per
cent as compared to particulate matter
emission from pre-Euro technology on
road buses.
Table 9.13 TNOs estimation on energy efficiency
Engine concept Energy consumption (baseline =100)
Diesel Baseline 100
Diesel with EGR 102
Diesel with De Nox catalyst 95
Stoichiometric LPG 128
Lean-burn LPG 117Stoichiometric CNG 125
Lean-burn CNG 114
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ALTERNATIVE AUTO FUELSCNG AND LPG 153
For conversion of old vehicles:
(a) In the case of older model petrol
passenger cars, a change over to
gaseous fuels, in most cases, results in
reduction in CO emissions, however
NOx in some cases may go up.Particulates are low in both cases.
(b) In the case of old generation diesel cars
and three-wheelers, conversion/
retrofitment/replacement of the engine
to four-stroke engine on petrol or
gaseous fuel gives benefits in terms of
reduced particulate matter emissions.
(c) In the case of diesel buses, a change
over to CNG results in benefits in
terms of particulate matter emissions,
with a disadvantage on CO and other
emissions.
(d) In the case of old generation two-
stroke petrol three-wheelers, a change
over to four-stroke engine provides
particulate emission benefits, both with
petrol and gaseous fuels, but there
may be a penalty on CO and NOx
emission.
(e) Road performance of alternative fuel
vehicles depends on the use of standard
kits of the right quality. While
adulteration in liquid fuels affects
emission performance, use/fitment of
sub-standard conversion kits adversely
affects emission performance in
alternative fuel vehicles.
In conclusion, both conventional auto
fuels and alternative auto fuels have theirinherent advantages and there is a need for
having optimal fuel and technology options.
The regulatory decisions with reference to
emission norms should, therefore, be
fuel neutral. The Committee has made
recommendations accordingly.
Safety related issues on the use
of gaseous fuels (CNG & LPG)
as auto fuel
CNG
Refueling:Refueling of petrol / diesel in
vehicles is a relatively simpler operation
requiring transfer of fuel at ambient
conditions whereas CNG is filled at very
high pressure of 200 kg/sq.cm (200 times
the atmospheric pressure). Any leak from
the filling nozzle or CNG kit and its
connected piping needs to be stopped
immediately which otherwise may lead to
an accident / fire / explosion. Therefore,
it is essential that filling operator is well
aware of the laid down safety precautions
including basic checks on the CNG
cylinder and the associated kit. The filling
station operator as such requires to be
trained and certified fit for the job.
Servicing of CNG Vehicles: CNG
vehicles are fitted with a high pressure
cylinder with associated piping, regulator,
pressure gauge etc. unlike petrol / diesel
driven vehicles where the transfer of fuel
from the tank to the engine is through a
simpler mechanism of fuel pump.During servicing / repair of CNG vehicles,
it is of utmost importance that the CNG
kits etc. are not tampered with. This
requires higher level of skill and safety
awareness among mechanics, and this
should be provided.
Any repair / replacement of the parts of
the CNG kit need to be done by
authorised agencies. With the progressive
growth in CNG, usage of spurious or non
standard components are suspected tofind a place in the market. Keeping in view
these factors, servicing / maintenance of
CNG fitted vehicles needs to be carried
out only by authorized garages/work-
shops equipped with proper facilities
and trained manpower.
Refueling of petrol /diesel in vehicles isa relatively simpleroperation requiringtransfer of fuel atambient conditionswhereas CNG is filledat very high pressureof 200 kg/sq.cm (200times the atmosphericpressure).
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154 AUTO FUEL POLICY REPORT
Conversion of petrol / diesel vehicles
to CNG: While various agencies and
workshops have been nominated for
retrofitting of approved cylinder and
CNG kits, there is a possibility that vehicle
owners may resort to non standard /
spurious equipment which may be fittedprimarily due to substantial cost
advantage. Use of such non standard
equipment or material may result in
catastrophic failure. In Delhi, over past
12 months, a total of 12 CNG vehicles
are reported to have caught fire, or have
had explosions.
Periodic Inspections: Keeping in view
the safety requirements associated with
high pressure gas, it is essential to carry
out periodic checks to ascertain the
integrity of the CNG kit. Third party
inspection is reportedly under
consideration of the Government of
NCT of Delhi. I&M mechanisms to
ensure this need to be put in place
urgently.
As per Gas Cylinder Rules, 1981,
every CNG cylinder needs to be hydro
tested once in five years. Regulatory
framework needs to be suitably expandedto meet the increased demand for such
testing and certification.
Training of drivers/passengers: In the
event of gas leak during transit, the
driver needs to be fully aware of the safety
measures to be taken to avoid a
catastrophe. Unlike the petrol/diesel
driven vehicles which can be stopped and
attended with relative ease and without
causing threat to the surrounding area,
special training of drivers is a must in thecase of vehicles using gas. Safety
awareness and emergency handling skills
need to be imparted through structured
campaign and programmes. OEM
manufacturers, TELCO and Ashok
Leyland are reported to have carried out
an awareness campaign to educate the
drivers and other personnel about the
safety aspects in Delhi. Not much
progress on putting in place a regular
mechanism appears to have been made
on this front. This work would need to
be attended to urgently by the
implementing State Governments.
LPG
LPG as an auto fuel was launched in Europe,
Japan etc. about 40 years ago. In Japan
during the initial phase of LPG introduction,
lack of adequate experience, knowledge and
safety consciousness of LPG on the part of
both service station employees and
customers as well as defects in vehicles and
components, caused incidents of gas leakage
and explosion which posed a serious socialproblem. To overcome this, Government,
industry, and user organizations discussed
ways to secure operating safety and agreed
to institute the following measures :
Application of fixed fuel containers in
vehicles.
Promotion of constructing new LPG
service stations by easing regulations on
safety distances in station.
Establishment of standards on the
structure and handling of passenger-
transport LPG vehicles.
Establishment of standards on road
transport safety as well as standards on
carburetor structure and maintenance.
Initially, replacement tanks were used which
have been changed to fixed tanks in Japan,
Italy etc. to ensure safety consideration. In
1962 and 1963, the fuel tanks of LPGvehicles, the process of switching over from
replaceable to the fixed system takes began.
Countries like Australia, US, Canada,
China, Taiwan, and UK, however, use fixed
cylinders. These countries have developed
standards for fixed type tanks with multi
functional valve assembly having various
safety features.
Keeping in view thesafety requirementsassociated with highpressure gas, it isessential to carry outperiodic checks toascertain the integrityof the CNG kit.
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ALTERNATIVE AUTO FUELSCNG AND LPG 155
Replaceable tanks are used as fuel tanks
only for stationery engines, fork lifts and earth
moving equipments. These vehicles are
generally slow moving, not registered for
road usage and are confined to limited area
for most of the time. The safety concerns
with the use of replaceable cylinders on theassemblies are as follows :
Possible use of spurious and sub standard
fuel tank and accessories not meeting the
safety requirements.
Handling of cylinders by untrained
mechanics and in unauthorized garages
not equipped with proper tools and
tackles, posing safety hazard.
Tendency to store extra LPG cylinders,
posing safety hazards around the storagearea, as the premises may not be fit
enough to store LPG cylinders.
Diversion of subsidized domestic LPG to
auto LPG cylinders by the unscrupulous
elements using make shift arrangements
not meeting the safety requirements, thus,
posing safety hazards.
With respect to the safety regulations for
LPG vehicles, the US has federal motor
vehicle safety standards and regulations
which have stipulated the requirements for
crash avoidance, crash worthiness, various
fittings and components. Similarly, other
countries have their own national standards
to take care of the safety issues.
In India, presently it is not mandatory to
subject the vehicle to a crash or collision
test and fuel system integrity test. These tests
for vehicles, for which facilities exist in the
country, should be developed in line with
the standards and practices prevalent inother countries and introduced as a
mandatory requirement for LPG fuel
vehicles. It is understood that facilities for
crash collision test are now available in India,
which should be used for such tests.
As per amendment of CMV Rules issued
on 24 April, 2001, LPG containers need to
comply with IS : 148199-2000, governed
by the Department of Explosives, which
specifies functional tests like bonfire test,
fatigue test and crash test. Further, ARAIs
standard for auto LPG tanks i.e. AIS 026
& AIS 027 specifications elaborate the
specific safety related checks for use of LPGfuels in internal combustion engine to power
wheeled motor vehicles and to 2/3 wheeled
motor vehicles, respectively.
Suggested measures
For the safety of alternative fuel vehicles,
the Committee suggests the following
Development / deployment of enough
skilled manpower for fuelling stationskeeping in view the growth in alternative
fuel usage. They should carry out visual
inspection in line withGas Cylinder Rules,
1981.
Setting up of workshops and service
centers by OEMs with adequate facilities
and skilled manpower specific to handling
of kits.
Setting up mechanisms for periodic
hydro-testing of cylinders and periodic
safety inspection of alternative fuel
vehicles and their accessories.
Training of vehicle owners and drivers for
effective control of situation in the event
of leak during transit.
Evolving an inspection and checking
system to prevent use of spurious
cylinders and kits and ensuring conversion
through an authorized garage and to see
that only genuine spare parts are used.
Specifications of CNG
and LPG
The proposed specification s of CNG as
auto fuel are given in Table 9.14 . The BIS
specifications of LPG as auto fuel are
given in Table 9.15 .
In India, presentlyit is not mandatoryto subject the vehicleto a crash or collisiontest and fuel systemintegrity test. Thesetests should bedeveloped in line withthe standards andpractices prevalent inother countries.
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156 AUTO FUEL POLICY REPORT
Table 9.14 Proposed specifications for CNG as auto-fuel in India
Constituent Value Tolerance
Wobbe Number 1350 +/- 20
Water, lbs/million ft3 0.5 Maximum
Hydrogen Sulphide, grains/100 ft3 0.1 Maximum
Other Soluble Sulphide, grains/100 ft3 0.1 Maximum
Carbon Dioxide, vol. % 3.0 Maximum
Oxygen, vol. % 1.0 Maximum
Hydrocarbons (% of Total Organic
Carbon Present)
Methane 80 Minimum
Ethane 10 Maximum
C3and Higher HC 5.0 Maximum
C6and Higher HC 1.0 Maximum
Total Unsaturated HC 1.0 Maximum
Other Species (mole %)
Hydrogen 0.1 Maximum
Carbon Monoxide 0.1 Maximum
Other Requirements
Free from liquids over the entire range of temperatures and pressures encountered in the engine and fuel
system.
Free from solid particulate matter.
Table 9.15 BIS specifications for automotive LPG (IS 14861-2000)
S. No. Characteristics Requirement
i) Vapour pressure (gauge) @ 40C, kPa
Min. 520*
Max. 1050
ii) C5Hydrocarbons and heavier, mol-%, Max. 2.0
iii) Dienes (as 1,3 Butadiene), mol-%, Max. 0.5
iv) Total volatile sulphur (after stanching) ppm, Max. 150
v) Copper strip corrosion @ 40C for 1 hour, Max. Class 1
vi) Hydrogen sulphide Pass the test
vii) Evaporation residue, mg/kg, Max. 100
viii) Free water content Nil**
ix) Motor octane number (MON), Min. 88
x) Odour Unpleasant and Distinctivedown to 20% Lower
Explosive Limit (LEL)***
* In winter, the gauge vapour pressure requirement shall be minimum 700 kPa at 40C. Winter
period shall be from 1st November to 15th February.
** The water content shall be determined at the Refinery/First Dispatching Location.
*** Product shall contain 20 ppm, min. ethyl mercaptan at the first dispatching location to ensure the
detection of leakage by odour.
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The view of the Committee on alternative
fuels (CNG & LPG) is summarized as
below :
The Committee finds that the market
conditions that have made the use of CNG
and LPG for automotive applications
commercially successful proposition as anormal fuel in other countries, do not
presently exist in India. It is seen that
both conventional auto fuels and
alternative auto fuels have their inherent
advantages and disadvantages and there
is a need for having an optimal fuel mix
and technology options that meets the
environmental objectives at least cost to
the consumer.
In view of the availability and security of
supply considerations brought out in
Chapter 7, relatively higher costs of
alternative fuels and investments
requirements detailed later in Chapter 13,
and the emission benefits achievable from
their use discussed in this Chapter, the
Committee is of the view that in the cities,
where tighter emission norms are
prescribed as part of any city specific
scheme to reduce vehicular pollution, with
a view to provide to the vehicle ownersin such cities, choices of different fuel and
technology options to meet such tighter
norms, necessary regime required for the
use of alternative fuel technologies and
supply of alternative fuels should be put
in place.
The Committee holds the view that in the
fast changing competitive market scenario
and developing technologies, it is
advisable to have an optimal mix of fueland technology to help development of
new technologies, promoting competition
and giving a fair choice to the consumer.
In the fast changing
competitive marketscenario and developingtechnologies, it isadvisable to have anoptimal mix of fuel andtechnology to helpdevelopment of newtechnologies, promotingcompetition and givinga fair choice to theconsumer.