Cng,Lpg Performance

8/2/2019 Cng,Lpg Performance

1/21

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


2/21

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


3/21


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.


4/21


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)


5/21


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.


6/21


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.


7/21


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.


8/21


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.


9/21


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.


10/21


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


11/21


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.


12/21


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.


13/21


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.


14/21


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


15/21


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.


16/21


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


17/21


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).


18/21


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.


19/21


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.


20/21


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.


21/21

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.

Documents

Cng,Lpg Performance