cng project

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Potential of CNG as a fuel for vehicles

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INTRODUCTION

Transport plays a significant role in the overall development of a nations economy. However,

this sector also accounts for a substantial and growing proportion of air pollution in cities. In

addition, the sector contributes significantly to greenhouse gases emissions and is a major

consumer of petroleum fuels.

According to recent WHO estimates up to one lakh people die annually because of the adverse

effect of the air pollution. As per Central Pollution Control Board (CPCB) a nodal pollution

monitoring authority in the country, automobiles contribute the highest amount of hydro

carbon in the air as much as 81 % of the suspended particulate Matter (SPM).

Delhi, being one of the most polluted cities in the world, has reached frightening proportions

with over 3000 metric tons of air pollutants emitted in the capital every day. Delhi figures in

the list of six cities, which have acute air pollution problems. The other such cities are

Mumbai, Kolkata, Nagpur, Ahmedabad and Kanpur.

Due to Projected increases in Gasoline/diesel vehicles use, even the strictest feasible

emissions controls on petroleum fuel vehicles will not substantially reduce total emissions.

The use of petroleum for transportation results in large quantities of pollutant emission from

vehicles, refineries and fuel stations. Light gasoline vehicles are a major source of non-methane hydro carbons (NMHC) and NO the main prcusors in Ozone and the single largest

source of CO. Heavy duty diesel vehicles are significant sources of NO. Particulate matter

(PM) and SO. NO and SO can cause acute and long term illness and premature death, reduce

agriculture productivity, damage materials, reduce visibility and contaminate ground water

and coastal areas. Altogether, transportation continues to be a major source of toxic air

pollutants in urban areas. Air quality is not likely to improve as long as petroleum is the

primary transportation fuel. Methane hydro carbons (NMHC) and NO the main precursors in

Ozone and the single largest source of CO. Heavy duty diesel vehicles are significant sources

of NO. Particulate matter (PM) and SO. NO and SO can cause acute and long term illness and

premature death, reduce agriculture productivity, damage materials, reduce visibility and

contaminate ground water and coastal areas. Altogether, transportation continues to be a major

source of toxic air pollutants in urban areas. Air quality is not likely to improve as long as

petroleum is the primary transportation fuel.

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Overview of the transport sector in India

In India, the share of the transport sector in GDP (gross domestic product) in 1997/98 was

7.3% (1993/94 prices). Road transport and the railways account for the majority of this

contribution. The transport sector is also the second largest consumer of energy, next only to

industry and commercial energy consumption about 98% of which is in the form of HSD and

gasoline, grew at the rate of 3.1% per annum in the 1970s and at 5.6% per annum in the 1990s

The relationship between transport and emissions in India is established via the use of fossil

fuels. The linkage between transport and the environment is particularly visible in the urban

transport sector due to the dominance of road transport. In addition, the transport sector

accounts for a large and growing proportion of Greenhouse Gas (GHG) emissions.

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GROSS CARBON EMISSIONS FROM ALTERNATIVE

TRANSPORT FUELS

The method used in this research has two main components. The first is an examination of

each energy industry in detail, using primary sources of data from power stations, oil

refineries and anhydrous ethanol production from molasses. The processes involved in each

case are examined, taking into account energy use in any necessary auxiliary activities to

evaluate the total carbon emissions. The second component is a detailed examination of one

specific form of public transport. This is a three-wheeled 8-seater used in the city of Lucknow

in North India. It is chosen because it is available with a petrol or compressed natural gas

(CNG) spark-ignition engine (and hence could alternatively be ethanol-fuelled) and in a

battery-electric version. Both parts of this data-gathering have been specific to the situation in

India. In energy conversion the refinery crude composition and processes, basic resources of

biomass and the mix of primary energy for electricity generation are different in each country.

The types of vehicle used also vary considerably from region to region. It is observed that

while CNG and electric-powered vehicles may have low and zero tailpipe emissions

respectively, gross pollution from such vehicles and their associated resource systems maybe

significant. In the case of electrically-propelled vehicles the gross carbon emission is

comparable with that for similar petrol-engine vehicles since about 80 % of electricity

production in India is fossil-fuel-based. In comparison, CNG shows a reduction of about a

third. Alcohol-fuelled vehicles, by comparison, can show neutral (i.e., zero net) carbon

emission. The importance of gross pollution assessments in rational choice of a fuel cannot be

overemphasised.

A life-cycle or so called well-to-wheel analysis of a fuel draws attention to the fact that

CO2 is produced not only in the combustion of a fuel at the point of use but also during

extraction, refining and transportation of the fuel. This indirect CO2 production is generally

associated with energy inputs in these processes but may also be related to the inherent nature

of the processes involved (Figure1).

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Figure 1. Net energy and gross CO2 emissions

G = gross energy produced by combustion of fuel

F = total feedback energy in fuel production processes 1, 2 and 3 = F1 + F2 + F3

N = net energy available from the fuel = G F

1. CO2 emissions

The sum total of such direct and indirect CO2 emissions may be termed gross CO2 emissions.

It should be pointed out here that, apart from CO2, emission of other polluting agents from a

fuel such as SOx, NOx, particulates, aldehydes and lead might also be considered. The present

study is limited to CO2 emission because of its serious implications for global warming. For a

transport fuel, the term life-cycle refers to althea events that begin from the source and end

at the wheel. In particular it includes stages of feedstock extraction, fuel processing and

refining, fuel transport, fuel storage and distribution, and finally combustion in the engine of a

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lower octane-rating hydrocarbon components to increase the percentage of more complex

octane-boosting molecules alters the chemical constitution of the petrol. This reforming

process consumes additional energy in the refining process energy directly lost from every

barrel processed. The addition of ethanol to petrol

Table 1. Process energy requirements

Process Energy

consumption

MJ/I

Energy recovered

MJ/I

Fermentation 0.95

Distillation 11.88Dehydration 4.84

Effluent treatment 3.30 11.27

Auxiliary equipment 0.21

Total 21.18 11.27

effectively gives the required octane boost and the reforming requirement is correspondingly

reduced. This means that every barrel of petrol blended with alcohol produced decreases crude

oil demand, not only by the quantity of petrol directly replaced by ethanol but also by the

crude oil saved through the value of ethanol as an octane enhancer [SEIS, 1980Unleadedpetrol

is now available in India but its use can create its own problems. Fuels containing high

proportions of aromatics and olefins produce relatively higher concentrations of hydrocarbon

compounds that have a potential to participate in reactions leading to the production of the

harmful photochemical smog. In addition, some aromatic compounds are known to be

carcinogenic and nerve toxins. For these reasons, the current trend favours the lowering of

aromatics content in petrol [Al-Farayedhiet al., 2000].

3. Gross carbon emission from anhydrous ethanol in India.

In the case where bioethanol is to be used in India as a petrol blend in road transport without

engine modifications, the use of anhydrous ethanol is essential [SEIS,1980]. Hence it is

important to carry out energy and environmental analysis of anhydrous ethanol production

from molasses as practised in India. With this objective, energy inputs in ethanol production

were obtained from a representative industrial alcohol plant located in the state of UttarPradesh (UP), India. The plant, which has a production capacity of 100 m cube/day, is

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operated on a three-shift basis (24 h/day). The production process consists of three stages:

fermentation, conventional distillation and dehydration, followed by effluent treatment that is

now mandatory for all distilleries. Energy consumption in each of these stages is in the form

of process steam and power derived from backpressure steam turbines. These turbines use

steam generated at 4.5 MPa (gauge) from bagasse-fired boilers.Bagasse is obtained through

backward integration of the distillery with a sugar mill having a cane-crushing capacity of

8000 t/day. The mill-wet bagasse contains about 50 % moisture and has a calorific value

[Gehlawat, 1990] of 9.5 MJ/kg.

Data recorded from the boiler and the back-pressure turbine used gave the following results :-

1 kg of steam generation requires 0.45 kg of bagasse, i.e., 4.3 MJ of primary energy.

1 kWh of power generation requires 7 kg of steam,i.e., 30 MJ of primary energy.

About 1400 m3 of spent wash produced per day from100 m3/day of distillate is

treated biologically via anaerobic digestion, generating biogas. Approximately 35m3

of biogas is generated per m3 of spent wash. This biogas, containing about 60 %

methane and having an approximate calorific value 23 MJ/m3, is fed directly into the

boilers to save bagasse.

The energy consumption recorded during various stages of ethanol manufacture is

summarized in Table 1 and more detail may be found in a previous paper by the

authors[Prakash et al., 1990].

4. Carbon emissions and uptake

There are significant carbon emissions in the form of CO2 during the production process of

ethanol. A large amount of CO2 is released during fermentation, as well as in the burning of

biogas and bagasse in the boilers used. CO2would also be released in transporting ethanol

from the distillery to the point of use and, of course, in its eventual

Combustion. In all of the above processes (except traditional transportation), however, the raw

material used (molasses) and energy inputs (bagasse and biogas) are derived from biomass

(sugar-cane) from the nearby fields. Therefore, one can safely assume that much of the carbon

released is eventually absorbed through photosynthesis insular-cane. Hence, in this case, gross

carbon emissions minus carbon uptake may be considered to be nil or, almost, very small.

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5. Gross carbon emissions from oil and CNG

An accurate assessment of gross carbon emissions froma fuel requires a detailed energy

analysis of its production process. However, indicative values of carbon release rates (as CO2)

for fossil fuel processing and combustion are available [Goldenberg et al., 1988] and are given

below:

Gross carbon emissions from natural - 13.5 kg per GJ released in combustion

gas

Gross carbon emissions from - 19.9 kg per GJ released in combustion

petrol

Specific energy content of - 46 MJ/kg

natural gas [Baruah, 1993]

Specific energy content of petrol - 42.9 MJ/kg

[Yacoub et al., 1998]

Hence, gross carbon emissions from natural gas

= (0.0135 kg/MJ) (46 MJ/kg)

= 0.62 kg C/kg of fuel

and gross carbon emissions from oil= (0.0199 kg/MJ) (42.9 MJ/kg)

= 0.85 kg C/kg of fuel

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Figure 2. Typical Vikram vehicles: 410P petrol-engined (left) and EV electric-powered (right)

To obtain the feedback energy requirement for CNG, energy data for compression were

obtained from the Gas Authority of India Ltd as follows.

In a typical CNG plant, natural gas is compressed from about 40 bar to 250 bar

through reciprocating compressors in a two-stage process.

The total electricity consumption in the process (compressor motors, oil pumps,

cooling water pumps, valves, etc.) was estimated to be in the range 0.6-0.7 kWhe/kg of

natural gas.

The initial compression of natural gas to 40 bar from the lowest pressure of about 3 bar

consumes an additional 0.2 kWhe/kg of natural gas.

Hence, the aggregate electricity consumption in compression averages about 0.85

kWhe!kg of natural gas. Carbon emissions (as C02) in conventional (coal-based)

electricity generation [Brown, 1992] are approximately 0.25 kg C/kWhe. About 80 %

of the utility power generation in India [MoF, 200 I] is thermal (mainly coalbased) and

the remaining 20 % comes from carbon-free (hydro and nuclear) resources. Therefore,

I kWhe power generation in India is associated with approximately 0.2 kg C emission.

Hence, gross carbon emission from I kg CNG = 0.62 + 0.85 x 0.2 = 0.79 kg C

6. Gross carbon emission from electric vehicles

To estimate gross carbon emissions from electric vehicles, practical data was obtained from

Scooters India Limited (SIL) at Lucknow (Uttar Pradesh), India. SIL is involved in the

manufacture, running and maintenance of its fleet of 8-seater three-wheelers. These are called

Vikram temposand are used for public transport in the city (Figure 2). Each vehicle uses 12

lead-acid traction batteries (6 V, 200 Ab) which run a DC series motor (72 V, 5.5 kW). The

average range of the vehicle on one charge is about 100 km and the data recorded from the

charging station shows electricity consumption in the range 16-18 kWhe for fully charging a

discharged battery bank. Since I k Whe power generation in India is associated with ap-

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proximately 0.2 kg C emission (as in the above paragraph), gross carbon emission from SIL's

electric vehicles is estimated as:

[(0.2 kg C/kWhe) x (17 kWhe)]/ [(l00 km) x (8 passengers)] = 4.3 g C/passenger-km

7. Comparative assessment of gross carbon emissions from various transport fuels

Apart from manufacturing electric vehicles, SIL is also involved in the manufacture of

petrol- and CNG-driven 8-seater three-wheelers for public transport. These are also known as

Vikram tempos as they are similar to the electric vehicles in design, but have an engine of 3.4

kW (200 cm3, 2-stroke) and steel chassis, unlike the fibre-reinforced plastics used for electric

vehicles. There is also a diesel vehicle but this is smaller and not directly comparable so has

been omitted from this study. Fuel consumption in the petrol and CNG-driven tempos was

observed as follows.

I kg CNG is required for 35 km average run or I I petrol for an average run of 18 km.

Considering gross carbon emission from petrol and CNG per kg of fuel, gross carbon

emission from SIL' s tempos is evaluated as: 4.4 gC/passenger-km for petrol-driven vehicles

and

2.8 gC/passenger-km for CNG-driven vehicles.

A comparison of the gross carbon emissions from various transport fuels in Indian conditions

is shown in Table 2.

8. Conclusions

It is concluded that bioethanol, as produced in India, can play a significant role in reducing

life-cycle carbon emissions. If used as a petrol blend, it can help reduce oil imports as well as

reduce aromatics pollution from unleaded petrol.

Table 2. Gross carbon emissions from various transport fuels

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Indicative values of gross carbon emissions from various alternative transport fuels have been

evaluated and are presented in Table 2. The table shows that gross carbon emissions from

electric vehicles are significant and are comparable with those from oil-fuelled vehicles, while

CNG is the least polluting among conventional fuels. This shows that although some fuels

may be "clean" locally, they can cause considerable pollution on a global basis. The study

further demonstrates that gross pollution from a fuel would decrease if clean and renewable

energy resources were used in its production process, as in the case of bioethanol manufacture

in India.

The study needs to be extended, of course, to assess gross emissions of other pollutants from a

fuel, e.g., SOx, NOx, particulates, aldehydes and lead, to obtain a comprehensive gradation of

fuels, thereby helping in the rational choice of a fuel.

A comparison with similar life-cycle assessments for automobile fuel/propulsion system

technologies for North America is provided below which further corroborates the conclusions

drawn above.

Comparison with similar life-cycle assessments for automobile fuel/propulsion system

technologies

Comparing fuels and propulsion systems requires a comprehensive, quantitative, life-cycle

approach to the analysis. It must be more encompassing than well-to-wheels analysis. Well-

to-wheels comprises two components, the "well-to-tank" (all activities involved in producing

the fuel) and "tank-to-wheel" (the operation/driving of the vehicle). The analyses must include

the extraction of all raw materials, fuel production, infrastructure requirements, component

manufacture, vehicle manufacture, use, and end-of-life phases (dismantling, shredding,

disposal/recycling) of the vehicle. Focusing on a portion of the system can be misleading. The

analysis must be quantitative and include the array of environmental discharges, as well as

life-cycle cost information, since each fuel and propulsion system has its comparative

advantages. Comparing systems requires knowing how much better each alternative is with

respect to some dimensions and how much worse it is with respect to others. Since focusing

on a single stage or attribute of a system can be misleading, e.g., only tail pipe emissions, the

lifecycle implications of each fuel and propulsion technology need to be explored.

MacLean and Lave [2003] have provided a very detailed review of a dozen studies on the life-

cycle implications of a wide range of fuels and propulsion systems that could power light-duty

vehicles in the US and Canada over the next two to three decades. The studies vary in the

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fuel/propulsion options they consider, the environmental burdens they report and the

assumptions they employ, making it difficult to compare results. All of the studies, however,

include the "well-to-tank" and "tank-to-wheel" activities and the majority of the studies

include a measure of efficiency and greenhouse gas emissions associated with these activities.

Comparison has been limited to these activities and measures.

Table Al provides a summary of the ranges of efficiency and greenhouse gas emissions

reported in the studies for the well-to-tank portion for the various options. For the well-to-tank

portion for the production of electricity, renewable fuels and hydrogen, differing fuel pro-

duction pathways are most important. Owing to the range of different production options for

these fuels (as well as other issues such as study assumptions), results are much more variable.

In addition, there is less experience with producing these fuels, resulting in more uncertainty.

It is important to distinguish between total and fossil energy required for production when

comparing efficiencies among the fuels. Petroleum-based fuels have the highest efficiency for

the well-to-tank portion when total energy is considered. However, if only fossil energy is

considered, biomass-based fuels such as ethanol become more attractive.

The tank-to-wheel portions are more difficult to compare. Each study uses its selected vehicle

(e.g., conventional sedans, light-weight sedans, pick-up trucks) and many present assumptions

regarding the vehicle efficiencies. The studies, however, do not generally report the range of

assumptions or test conditions.

Table A1. Comparison of life-cycle inventory studies: well-to-tank

efficiencies and greenhouse gas emissions

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Notes

1. Efficiency (%) is defined as: (energy in the fuel delivered to consumers/energy inputs

to produce and deliver the fuel) 100, e.g., 100 MJ of energy input results in 80-87

MJ of petrol delivered to the consumer.

2. Negative GHG emission values for ethanol result from carbon sequestration during

feedstock growth as well as if a credit is given for selling excess electricity (produced

through cogeneration schemes) to the grid and therefore offsetting CO2 emissions from

conventional electricity generation.

The well-to-wheel results (the sum of the well-to-tank and tank-to-wheel activities) of the

studies are still more difficult to compare. The baseline vehicle (with a few exceptions) is a

current petrol-fuelled ICE port fuel injection vehicle; it combines an efficient well-to-tank

portion with a relatively inefficient tank-to-wheel portion. A direct injection diesel vehicle is

considerably more efficient and therefore results in lower emissions of carbon dioxide even

though the carbon content in the diesel (and hence the well-to-tank portion of the C02

emissions) is higher than that in petrol. Fuel-cell vehicles have a high theoretical efficiency

but generally a low-efficiency well-to-tank portion, which offsets some of the vehicle

efficiency benefits.

Table A2 shows the ranges of values reported in the life-cycle studies for the well-to-wheel

greenhouse gas emissions. All of the fossil fuel options result in emissions of large amounts of

greenhouse gases. Ethanol and hydrogen have the potential to reduce greenhouse gas emis-

sions significantly. This, however, is highly dependent on the pathways for ethanol and

hydrogen production, especially the amount of fossil fuel inputs during production. Some of

the hydrogen options result in higher greenhouse gas emissions than those of a petrol ICE

vehicle. Results for hybrid electric vehicles (HEVs) are dependent on the efficiency

improvements over conventional vehicles that are assumed.A numerical comparison of C02

emission data presented in Table A2 with those reported in Table 2 should be made with

caution. The large differences in numerical values arise from the differing manner in which

C02 emissions have been expressed. In Table 2, emissions are expressed in grams of carbon

(only) released as CO2 per passenger-km travelled. In Table A2, emissions are in grams of

C02 equivalent per km travel of the vehicle examined. C02 equivalent refers to the amount of

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carbon dioxide by weight emitted into the atmosphere that would produce the same radiative

forcing as a given weight of another greenhouse gas, e.g., methane or oxides of nitrogen.

Carbon dioxide equivalents are the product of the weight of gas being considered and its

global warming potential.

Table A2. Comparison of life-cycle inventory studies: well-to-wheel

greenhouse gas emissions

Numerical differences not withstanding, broad conclusions drawn by MacLean and Lave are

very similar to what has been obtained under Indian conditions in this article: all of the fossil-

fuelled vehicles (including electricity-driven) result in large GHG emissions. The two options

that have potential for the largest GHG emission reductions are the ethanol and the hydrogen-

fuelled vehicles if the fuels are produced with little or no fossil fuel inputs.

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COMPRESSED NATURAL GAS (CNG)

What is CNG? Properties of Natural Gas:

CNG is the short form of Compressed Natural Gas. The Natural Gas has less energy density

as compared to Liquid Fuel and hence it is compressed to over 200 Kg/cm (g) pressure to

make it CNG for use in the automobile sector. In its natural form it is colourless, odourless,

non-toxic and non-carcinogenic. However, this natural gas is mixed with an odorant to add

flavour similar to the odour of LPG from a domestic cylinder so asto facilitate detection of its leakage. The typical composition and physical properties of CNG

(i.e. Compressed Natural Gas) is as follows:

Typical Composition:

Methane : 88%

Ethane : 5%

Propane : 1%

CO2 : 5%

Others : 1%

____

Total : 100%

Physical Properties:

Non-toxic Natural gas being lead/sulphur free, its use substantially reduces harmful engine

emissions. When natural gas burns completely, it gives out carbon dioxide and

water vapour - the very components we give out while breathing!

Lighter than air Natural gas being lighter than air, will rise aboveground level and disperse

in the atmosphere, in the case of a leakage.

Colourless Natural Gas is available in the gaseous state, and is colourless.

Odourless The gas in its natural form is odourless, however, ethylmercaptan is later added

as odorant so as to detect its leakage.

Compressed Natural Gas (CNG) is used as a fuel in transport sector in many countries. It is a

safe, clean burning and environment friendly fuel. It has been established that exhaust

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emissions like hydrocarbons and carbon monoxide are significantly reduced as compared to

other fuels. Toxic emissions such as lead and sulphur are completely eliminated. Existing

petrol vehicles can use CNG by fitting a conversion kit. The CNG converted vehicles have the

flexibility of operating either on petrol or on CNG.

An experimental programme to use CNG as fuel in transport sector in the country was

initiated by GAIL in 1992, whereby CNG was made available in Delhi, Mumbai and Baroda.

The supply of CNG in Mumbai and Delhi are managed by two joint ventures viz. Mahanagar

Gas Nigam Ltd. and Indraprastha Gas Limited respectively and in Surat and Ankleshwar, by a

private company. The average cost of converting a petrol car to CNG is about Rs.35,000.

There are over 10,000 CNG converted Petrol vehicles in Mumbai and over 3000 such vehicles

in Delhi. 11 buses of DTC are running on CNG in Delhi, with 2 existing diesel buses

converted to CNG on trial basis.

CNG dispensing retail outlets on mother-daughter concept as well as online dispensing units

have been set up in Delhi. Under the former system, Natural Gas is compressed and filled into

truck mounted cascades (basket of cylinders) in the mother compressor station and transported

to daughter units for dispensing to CNG vehicle. The mother station initially set up in

Ghaziabad has been re-located and brought near to Delhi at Sarai Kale Khan, in May97. At

present there are seven daughter and four on-line dispensing retail outlets in Delhi. Further

expansion of the infrastructural network to 80 CNG outlets is proposed by March 2000. The

process of acquiring land sites to set up the required number of outlets is going on.

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WHY CNG?

Reasons for switching over to this alternate fuel are mainly:

1. Economic benefit: The cost of CNG is almost a third of the cost of Petrol in terms of

calorific value resulting in substantial saving in fuel cost, and investment on the CNG kit is

paid back in a short period

2. Environment friendly: The use of CNG as a fuel reduces vehicular exhaust emissions

significantly. Carbon Monoxide emissions are reduced by 70 to 90% and Hydrocarbon

emissions by 40 to 60% as compared to vehicles that use the conventional fuel - Petrol.

Carbon Dioxide emissions, a cause for global warming, are also reduced significantly by 10%

3. 100% Income Tax Depreciation: Corporate Organisations, firms, etc. can claim 100%

depreciation on a CNG Conversion Kit as this is a pollution controlling equipment.

Organisations that buy CNG Conversion Kits should consult their Income Tax Consultants

and avail of the depreciation benefits4. Flexibility and ease of use: The basic engine characteristics of a vehicle are retained while

converting it to run on CNG. The vehicle therefore is capable of running either on Petrol or

CNG at the flick of a switch on its dashboard.

The Fuelling Process

There are very few CNG refuelling stations. Of the ones that exist, there are three basic types.

Fast fuelling stations which take five to ten minutes for refuelling, ideal for retail roadside

pumps. Slow fuelling stations which take from five to eight hours to fill, ideal for a fleet of

vehicles which have a long idling time. Combined Fast and Slow fuelling stations which can

cater to both the above categories.CNG is stored at compression stations which are directly

connected with the gas pipeline. Here the gas is compressed to a required pressure and aids

fuelling. CNG can also be transported to other retail outlets by cylinder trucks. these trucks

carry a number of cylinders which provide CNG to fuel stations which are not connected by

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pipelines. These fuelling stations could be placed alongside petrol and diesel pumps too. the

whole process requires proper infrastructure and transportation.

Bi-fuel Possibility

Vehicles can also be operated in the dual mode like Petrol-CNG and Diesel-CNG.

Experiments of these kinds have been conducted on vehicles by TELCO,Kirloskar Cummins

Ltd., Ashok Leyland, IBP, OIL, Delhi transport Corporation and Gujarat Road Transport

Corporation. The results were quite satisfactory.

The Gas Authority of India Limited (GAIL) has requested vehicle manufacturers to nominate

workshops and undertake conversions on their vehicles. The actual performance could be

monitored by the Indian Institute for Petroleum (IIP), Kit suppliers from Italy and New

Zealand have joined hands with oil marketing companies and vehicle manufacturers to train

and initiate conversion from petroleum products to CNG.

Many countries around the world, including India, have abundant reserves of natural gas.

Hopefully, it is only a matter of time when things begin to take a turn for the better and CNG

would be as prevalent as petroleum products.

|

What does the kit comprise of ?

1. The Cylinder

The cylinder is used to store CNG at a working pressure of 200 bar. It is fitted with a shut-off

valve and a safety burst disc. The cylinders are type approved by the Chief Controller of

Explosives, Government of India.

2. The Vapour Bag.

Fitted onto the cylinder, the Vapour Bag is used to enclose the cylinder valve and the pipes

connecting it and is vented out of the car

3. The High Pressure Pipe

This High Pressure Pipe connects the refuelling valve to the CNG Cylinder and Pressure

Regulator

4. The Refuelling Valve

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The Refuelling Valve is used to refuel the CNG cylinder

5. The Pressure Regulator

The Pressure Regulator has a Solenoid Valve to shut-off gas supply to the engine. The CNG

stored at a high pressure in the cylinder is reduced to just below atmospheric pressure by this

unit. This negative pressure is also a safety feature that will not allow gas to pass through

when the engine is not running.

6. The Gas-Air Mixer

The Gas-Air Mixer is a unique component, specially designed to suit each engine model. It

precisely meters gas fed into the engine.

7. The Petrol-Solenoid Valve

The Petrol-Solenoid Valve is used to cut off petrol supply to the engine when it is run on CNG

8. The Selector Switch

The Selector Switch is fitted at the dashboard, enabling the driver to choose either the CNG

mode or the petrol mode of operation. The electronics built into this unit also ensures safety

by switching off the gas solenoid whenever the engine is switched off. It also serves as a fuel

indicator for the quantity of CNG available in the cylinder

POLLUTION REDUCTION IN CNG FUELLED VEHICLES

The use of CNG in vehicles has lead to considerable reduction in air pollution as is evident

from the following data:

A. Auto rickshaw Three wheelers:

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B. Passenger Cars:

C.Diesel Buses:

Pilot project of GAIL :

Objective: A pilot project was initiated by GAIL (India) Ltd. in collaboration with

Indian Institute of Petroleum, Dehradun to establish the feasibility of using CNG as an

alternative to liquid fuels such as Diesel & Petrol used by buses & automobiles in 3

cities namely Delhi, Mumbai & Baroda.

Infrastructure of GAIL under pilot project: 1 Mother station was initially put up at

Ghaziabad which has since been shifted to Seakale Khan. This mother station was

feeding to 5 daughter stations in Delhi. 3 Nos. online stations were added making total

9 Nos. of Cogitations during the pilot phase of the project. The station design and

safety norms followed were as per New Zealand standards.

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CNG CONSIDERED AS ALTERNATIVE FUEL :

CNG is totally safe. It is non-toxic, non-corrosive and non-carcinogenic (totally free from

cancer inducing agent). CNG being predominately methane (CH4) is 0.6 times lighter then

air while petrol is 3-4 times heavier. Being lighter then air, it disperses fast unlike petrol or

LPG, which tends to remain around the place of leakage. CNG does not catch fire easily, as it

requires a much higher concentration of 5.15% in the air to ignite against the 1.8 % required

for petrol. CNG also requires a higher ignition temperature of 540O C as compared to with

petrol, which requires 232-282 O C, which prevent CNG from catching fire as quickly as

petrol. CNG cylinders are very robust materials, which minimizes the chances of leakage.

CNG promises a breath of fresh air and is environmental friendly. CNG is lead-free and

substantially reduce the harmful engine emission to keep the surroundings and air clean.

CNG INTRODUCED AS ALTERNATIVE FUEL :

A special report of Environmental Pollution and Control Authority (EPCA) Committee

headed by Sh. Bhurey Lal comprises of Secy. Transport, Delhi Government, A member from

Center for Science and Technology and a member each from Ministry of Environment and

Ministry of Petroleum suggested use of CNG in all commercial vehicles in NCR in addition to

ban on registration of diesel cars in Delhi. However, the Delhi Government was in favour of

propane gas as alternative fuel and set up a propane gas station for DTC buses but the Center

did not approve the propane conversion kit. Even the option was not favoured by Sh. Bhurey

Lal Committee. Thus the Honble Supreme Court accepted CNG as alternative fuel for

Gasoline and diesel vehicles.

DEADLINE OF 31.3.2001 FIXED FOR POLLUTING VEHICLES :

The Honble Supreme Court vide its orders on 28.7.1998 fixed the dead line of 31.3.2001 for

gasoline/diesel run commercial vehicles in view of the June 1998 affidavit of Secretary

Transport Delhi Government assuring that the City Bus fleet could be converted to CNG

mode by 31.3.2001.

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CNG TECHONOLOGY ---TESTED & EXPERIENCED

CNG has been successfully used as auto fuel in several countries. As of now, there are more

than 12 lakh CNG driven vehicles in the world. Argentina, Canada, Italy, New Zealand and

USA are among the countries where CNG is being used as auto fuel for some years/. Pakistan

is also successfully running a staggering 1, 60,000 vehicles on CNG. Almost entire transport

system is running on CNG in Pakistan. This conversion process has been on the past five to

six years. Most vehicles in Japan run on LPG, but , now they are also opting for CNG. Even

Bangladesh is also in its way to convert its transport fleet to CNG mode. In India, Mumbai has

been the first to use the CNG mainly for taxies.

VEHICULAR AIR POLLUTION IN DHAKA: The air pollution in few big cities of

Bangladesh is a very serious concern. As per a World Bank Study, as many as 15000 deaths

(5000 in Dhaka), a million cases of sickness requiring medical treatment and 850 million

cases of minor illness can be avoided annually if air pollution levels in the countrys four

principal cities are reduced to match standards in force in developed countries. The same

report further estimates the economic cost of these avoidable deaths and sickness to be US $200 to 800 million every year. Dhaka has heterogeneous traffic flows. Three wheelers, out of

which ninety percent are two stroke engines baby taxis and two wheelers, are dominant in the

vehicle fleet in terms of both number and mileage. The number of two stroke engine three

wheelers has tripled from 1990-96. Air pollution levels in Dhaka are considerably higher than

the Bangladesh standards or the World Health Organization (WHO) guidelines for residential

areas. Most experts here blame three-wheelers with two-stroke engines and the heavy-duty

diesel vehicles for the high pollution levels. They see leaded gasoline as the principal source

of lead in the atmosphere. As many countries have phased out leaded gasoline, Bangladesh is

also working on the problem. Due to pressure from green lobby to reduce air pollution in

Dhaka, the government decided that three-wheelers would be made to run on non-polluting

compressed natural gas (CNG). Initially, all such decisions remained on paper. The reason

might be that there was support for converting three-wheelers to CNG instead of banning

them so as to prevent the sudden unemployment of at least 250,000 people. Here it is worth

mentioning that motor vehicles per thousand people in Dhaka city is still low in comparison to

other capital cities of developing countries but the likely higher economic growth in the future

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with even faster increase in population will definitely result in fast growth in vehicles fleet in

Dhaka. Besides the composition and size of vehicle fleet, poor maintenance, excessive

commercial use, fuel adulteration, use of lubricants of sub standard quality and poor

management of traffic will further result in severe congestion and vehicular pollution in

Dhaka.

Keeping in view the above problems, Dhaka Urban Transport project was launched by the

Government of Bangladesh and the Dhaka City Corporation. The International Development

Association (IDA), the World Banks concessionary arm approved the credit of US $ 177

million for the project. The Government also wanted to develop an Air Quality Management

System to reduce Dhakas severe air pollution. The World Bank provided Bangladesh a $ 4.7

million Learning and Innovative Loan in 2000 for a Bangladesh Air Quality Management

Project (AQMP) under which Dhaka would pilot new ways of controlling urban air pollution.

Next step in the direction of reducing air pollution in Dhaka is to popularize the use of CNG

vehicles, as in many other cities of the world.

ECONOMICS OF CNG VEHICLE PROGRAM IN DHAKA: Worldwide, improving air

quality in urban settings has been a long-standing planning objective and road transport using

diesel vehicles has been identified as major contributor to such air pollution. To help address

this problem, increasingly stringent vehicle emission standards came in to force worldwide. It

also stimulated research into alternative fuels and technologies that promise cleaner and lower

emissions. Various fuels that are alternatives to diesel and petrol have been proposed for use

in vehicles. Alternative fuel vehicles use such fuels as compressed natural gas (CNG),

liquefied natural gas (LNG), methanol, ethanol, bio-diesel fuel and propane. Among these

fuels, Natural Gas, either in the form of CNG or LNG, is more in the news. Reasons behind

the popularity of these fuels are economic as well as environmental. Many countries like

Argentina, Canada, Italy, New Zealand and United States of America have substantial NGV

programs. Brazil, Chile, China, Colombia, Egypt, India, Indonesia, Mexico, Pakistan and

Thailand are in various phases of developing such programs.As early as in 1985-86,

Bangladesh Petroleum Corporation started a project to use CNG in vehicles instead of

Gasoline. The World Bank donated Tk 225.1 million to initiate the project. The primary

objective of this project was to reduce vehicular emissions as combustion of CNG produces

less pollutant than the gasoline.After a decade in 1996, there were only 86 vehicles converted

under the project, while in that year the volume of traffic in Dhaka only was composed of

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84411 cars, 9135 buses, 15600 trucks, 66360 three wheelers and 121156 two wheelers. In year

2002, there were only five CNG filling stations in Dhaka, out of which 4 has been established

by Rupantarit Prakritika Gas Company Limited (RPGCL) and one was in joint venture

between a Chinese company and RPGCL. The gas supply to these filling stations was quite

erratic, particularly during morning hours when gas pressure decrease due to domestic use.

The need was felt to create an efficient transmission and distribution network to improve and

secure a reliable supply of gas. Further, as conversion of vehicles to CNG has now become

imperative to save the city from the menace of air pollution that has turned the capital into

almost a 'gas chamber', need was felt to set up number of CNG filling stations to cater the

growing demand when large numbers of vehicles get converted to CNG. Realizing the

urgency the Bangladesh Government has taken up the CNG conversion process issue within

its 100-day action plan for implementation. To expedite the process, the government has

already given permission to 13 private companies to set up CNG conversion units. The

economic benefits arising from the CNG vehicle program in Dhaka are expected to accrue to

consumers of various categories such as vehicle owners, users of transport, workers and the

economy in general. Additionally, benefits on account of improved environment and thus

health status of the population in Dhaka and macro economic contribution of the CNG

program for further development of the energy and particularly, gas sector are equally

important.

Economic Benefits to Vehicle Owners & Users:The amount of consumer surplus

(economic benefits) arising from CNG Program will directly benefit the vehicle owners.

Operating cost of CNG vehicles is lower than that of vehicles run on alternate fuel i.e. petrol

or diesel. Thus vehicle owners will benefits from reduced operation costs in terms of resource

cost savings. For instance, if hundred percent of the bus fleet of the Dhaka is converted to

CNG, the present value of likely stream of economic benefits in terms of resource cost savingsin the coming twenty years period, at twelve percent rate of discount, will be about 16000

million Taka. Similarly, the conversion of whole vehicle fleet of Dhaka to CNG will fetch the

present value of likely stream of economic benefits in terms of resource cost savings over a

twenty year period, at twelve percent rate of discount, to the tune of 32000 million taka .

However, the experience shows that vehicle owners will not transfer a portion of consumer

surplus to end-users. Therefore, intervention by Government / administration is required to

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ensure that end users of transport also get a share in consumer surplus arising from transport

component in the proposed project.

Benefits to Operators of Filling Stations:Another potential beneficiary of the CNG program

will be the CNG filling station operators because the demand for CNG as fuel is going to

increase and they will earn from the increased sale of CNG. Initially, the profit might not have

been significant because of low gas pressure leading to sub optimal sale proceeds at the end of

the day. However, their income will significantly increase due to the program that will ensure

the regular supply of gas with optimum pressure

Network Benefits: Total consumption of gas by vehicle fleet of Dhaka will be less than the

supply of gas provided by an optimum size of the transmission and distribution network.Therefore, consumers of other categories such as households, commercial or industrial

consumers will consume the additional supply of gas, over and above the consumption by

transport in the city. Discussions (by author a year back) with RPGCL, the distributor of gas

in Dhaka, revealed that presently, the supply of gas is less than demand, particularly during

peak hours. It results in lower than optimum supply pressure in the existing gas distribution

network and thus existing consumers did not get the proper supply of gas. As suggested by

officials of RPGCL, the investment in up gradation and augmentation of gas transmission and

distribution network will help in improving the supply of gas to existing consumers by

maintaining optimum supply pressure in the network. The possible consumers of the

additional supply of gas by the upgraded network may be grouped under to heads depending

upon the physical location of the newly added transmission and distribution network and its

area of coverage. First group will be households and commercial consumers in the Dhaka city

and other possible consumers may be industries in the outer periphery of Dhaka. In case of

first group of consumers, i.e. household and commercial, economic benefits on account of

improved network for supply of gas will be in terms of resource cost savings because the cost

of natural gas is lower than that of other alternate fuels. In other words, consumers will be

able to get same amount of energy, which they used to get from alternate fuels, by spending

less. Such benefits will occur to existing as well as new consumers.In case of use of gas in

industry, the economic benefits will be in terms of net incremental output (net value added) to

the economy. The quantum of such benefits depends upon the type of industries likely to

consume the additional supply of gas. Discussions with officials of RPGCL indicated that a

few gas based power plants have been proposed in Dhaka region, which may be the likely

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consumers of the additional gas supply. This possibility becomes even more likely in the light

of the fact that the gas based power plants in Bangladesh are not getting the requisite supply of

gas for power generation. However, possibility of supplying gas to industries in outer Dhaka

region simultaneously with the supply to CNG filling stations may not be feasible because of

the incompatible spatial patterns of industrial development and spread of city. Therefore, the

network benefits are more likely to occur to household and commercial consumers.

Health Benefits due to Reduced Pollution : Proportionate share of Dhaka in reported cases

of death and sickness was taken on the basis of proportionate share of Dhaka in the total

population of major cities of the country and thus, economic benefits associated with reduced

health problems due to use of CNG was estimated for the city. The benefits in terms of

savings in cost of health impact due to air pollution was estimated under three heads, viz. loss

of human capital deaths due to air pollution, loss of work person days on account of sickness

due to air pollution and expenditure on treatment.

The estimated cost of health problem due to air pollution in Dhaka comes to about Tk 25000

million per year. In other words, Tk 25000 million as health benefits can occur to the

economy, if an air pollution level in Dhaka is reduced to match standards in force in

developed countries.

MacroEconomic Benefits -Foreign Exchange Savings: It is generally argued that market

for gas in Bangladesh is limited This argument seems misplaced when demand scenario for

gas in Bangladesh is analyzed in the context of possibilities of replacement of other imported

fuels such as petrol and diesel by gas. Judging from the size of the oil bills in the BOP, the

fact of the matter appears to be that Bangladesh had been an energy deficient

country.Projections [ by Power System Master Plan (PSMP) put the likely growth in energy

demand in Bangladesh at 10% per annum. Assuming the same rate of growth in demand for

petrol and diesel, calculations reveal that demand for these energy products is going to be

more than four times after 15 years.

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Projected* Demand for Petrol and Diesel in Bangladesh

000 MT

Year Petrol Diesel

1995-96 174.00 1303.00

2000 280.00 2098.00

2005 451.00 3378.00

2010 726.00 5438.00

2015 1169.00 8755.00

Projections are based on power demand forecasts made by the Power System Master

Plan (PSMP), which predict that power demand is going to grow at 10% per annum in

the country.

Keeping in view the current import bill of the country for these fuels, limited available

reserves of petroleum and exploration activities there, the domestic production is not going to

meet this increasing demand. To meet the increasing demand for petrol and diesel there are

two options available with the government- either increase the imports or replace the use of

these fuels by domestically produced natural gas.

The first option has no economic logic. For example, in 1995-96, 1007 thousand MT of diesel

was imported which was valued at 183 Million US$. Assuming that the ratio between

imported fuels and domestic production will remain the same, as at present, and demand

growth will be as predicted by PSMP, the likely quantum of import of diesel alone will be

about 6700 thousand MT in 2015.

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Projected Imports of Diesel in Bangladesh

000MT

Year Diesel

1995-96 1007

2000 1621

2005 2610

2010 4206

2015 6775

Thus, considering the existing level of imports of these products and precarious position of

foreign exchange reserves, Bangladesh cannot afford to depend on imports of energy fuels to

meet the increasing demand.The other viable option is to replace the petrol and diesel by

natural gas as a fuel in industry and transport.For example, let us consider the case of

replacing use of imported diesel by domestically produced natural gas in the industry and

transport sector, and resulting foreign exchange savings. Since the replacement of diesel with

gas is a gradual process and takes few years to fully materialize, the savings in foreign

exchange will be smaller in the initial years. But after 4-5 years such savings will pick up.

Thus the import substitution may save the country foreign exchange to the tune of about US$

90 Million in 2005, which may increase to about US$ 330 Million in 2010.

Other Prospects: Presently, the industry contributes only about 18% of GDP in Bangladesh.

But the analysis of historical changes in structure and composition of GDP in industrialized

and newly industrialized countries indicate that the relative share of industry, transport and

services sector in the GDP increases with the increase in per capita GDP and industrialization.With such structural changes in the economy of Bangladesh, the per capita consumption of

energy will also increase and, in this context, the role of gas sector as a strategic sector to pick

up the economic growth is very crucial. As the demand for energy increases in the economy

the gas sector will develop further and cater to the demand either by increasing supply in its

present pattern of usage and or through import substitution. The CNG vehicle program in

Dhaka will play the role of catalyst to speed up the process of development in the gas sector.

Here, it is timely to comment that the need is to link energy sector growth strategy with trade,business, industry and agriculture growth strategy in the mid to long term. Besides, further

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development of gas sector will help Bangladesh to export gas to earn foreign exchange.

Although the decision to export gas is a political one, but possibilities of export are

intrinsically related with the development of domestic market for gas. Activities related with

development of domestic gas market such as CNG program in Dhaka give impetus to gas

exploration and infrastructure development activities, and thus set the stage for export of gas.

Ultimately, it will help in picking up the industrialization and economic growth through

forward and backward linkages and thus further expansion of the domestic and international

market for gas.

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GETTING INTO THE CNG MODE

HOW TO GET PETROLEUM VEHICLES INTO CNG MODE:

Petrol/diesel vehicles can be made into CNG mode by:

1) Replacement of petroleum vehicles into new CNG vehicles Retro fitment with new CNG

engines

2) Conversion of petrol/diesel vehicles to CNG mode

CONVERSION TECHNOLOGY APPROVAL OF :

Conversion technology was developed by the Indian Institute of Petroleum, Dehradun (U.P).

The technology was reported to be quicker and extremely cost effective. Delhi Government

approved this scheme of conversion of petroleum vehicles into CNG mode on 20.10.1999.

The Honble Supreme Court on 16.2.2001 ordered that only those CNG buses to ply on Delhi

Roads which are certified by the Retro fitting companies authorized by any of the following

testing authorities:

Automobile Research Association of India, Pune (Maharashtra).

Vehicle Research & Development Establishment, Ahmednagar (VRDE).

Indian Institute of Petroleum, Dehradun (U.P).

On the basis of approved conversion technology, the conversion of diesel bus to CNG mode is

first major technology achievement of India in the World.

Transporters/Operators have been cautioned to get it install the CNG kits at a workshop

authorized by its suppliers or Manufacturer.

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PROBLEMS FOR CNG COMPLIANT BUS BODIES:

Government envisaged the body fabrication problems. No single fabricator was able to supply

the bus bodies as required in view of the limited time. Hence the body fabrications work was

allotted to distant body fabricators at Mumbai, Jamshed Pur and Ahmedabad in addition to in

and around Delhi. Couple of months was wasted in getting the Railway to ferry the CNG

chassis to distant body fabricators. Later on the chassis were transported through pullers,

which costed an increase of Rs. 1 lakh per bus body fabrication because Indraprastha Gas

Limited shown its inability to provide mobile cascade enroute for filling CNG chassis.

CNG - TECHNOLOGY:

The authorized manufacturers built up about 2200 new CNG buses, which started plying on

Delhi Roads by using an obsolete ignition system, which resulted a incident of fire causing

injuries to five persons on 5.8.2001.

These buses have a distributor based ignition system, which can be dangerous if the CNG

cylinders are leaking. The distributor produces sparks, which ignites the CNG gas inside the

ignition chamber. In addition, distributors also produce sparks outside the chamber. Thismakes them vulnerable to the highly inflammable CNG. It is a first generation system, which

has been discarded in many countries. It is not known that why our manufacturers in India are

using the dangerous technology. China has been the latest to ban this obsolete technology.

These new CNG buses with distributor based ignition system are moving bombs on our roads.

They need immediate replacement.

No doubt CNG is a safe fuel, but if it is exposed to sparks, it bounds to catch fire. The safest

option is third generation distributor less ignition kits. It produces sparks inside the ignition

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chamber and not outside. It is entirely controlled by computer driven system. It is learnt that

this technology is being adopted by our conversion companies.

SAFETY NORMS FOR CNG-RUN-SYSTEM :

Safety norms for CNG run vehicles have not been notified till now. It is learnt that the draft

safety norms drawn by Bureau of Indian Standards are under process of approval and are

likely to be finalized and approved by the end of this year i.e. 2001. There are no

comprehensive legally enforceable rules to govern the safety of CNG vehicles plying on Delhi

roads and interim draft prepared by the Pune based Automobile Research Association of India

is only document which lays down the safety standards. Safety norms should be specified in

the Central Motor Vehicles Rules. In the absence of Law, many violators can go scot-free.

CNG run vehicles norms are in the nascent stage globally as well. The norms evolved by the

International Organization of Standards (ISO)- the Apex body under the United States

Umbrella are also in the final draft stage.

Safety and maintenance go hand by hand, when one talk about CNG with Delhis entire

commercial vehicles fleet being converted to the CNG mode, safety concerns need to be

addressed on priority. Norma applicable to diesel buses are being adopted for CNG buses.

REQUIREMENT FOR THE COMPONENTS OF CNG RUN SYSTEM:

The requirements for the components of CNG run system have been drawn considering the

draft norms of BIS, which are briefly discussed as under:

DESIGN:

Design requirements for CNG run systems are:

i. Withstand changes in environmental temperature and other echo conditions safety

during operational life.

ii. Be located with full regard for anticipated damage. Such damage may be caused by

input from the vehicle or by extraneous input such as heat, road debris, automotive

chemical splash (brakes liquid, oil, and petrol, cooling liquid, by rust and so forth.

iii. Be fitted so that they are not the outer most, highest or lowest parts of the vehicle.

iv. Be fitted so as not effect ground clearance, approach angle, ramp angle and departure

angle.

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v. Be located so that they will not suffer corrosion by accumulation of water and cargo

chemicals.

RECEPTACLE:

i. It shall be provided with a cap to prevent the entry of dust and foreign metal.

ii. The fuel type, expiry date of the gas cylinder and the service pressure for the vehicles

written in permanent ink should be displayed near the receptacle.

GAS CYLINDER:

General requirements :

i. Gas cylinder shall be provided with the cylinder valve and pressure relief devices.

ii. To prevent heat damage, they should either use a heat shield or be located with respect

to the exhaust system, so that their side temperature shall not exceed the value

specified by the vehicle and the cylinder manufacturer.

iii. All gas cylinders shall be protected from ultra violet radiation.

iv. The gas cylinder shall be securely attached to the vehicle to prevent it from slipping,

rotating and dislodging.

BODY:

CNG cylinders are made from seam less tubes of alloy steel skin to oxygen cylinder This

ensures there are no joints and the walls of the cylinders is made of very robust material. This

also prevents leakage.

SIZE AND DENSITY OF CYLINDER :

The density of material (alloy steel) is around 7.86 gms per cubic centimeter. Original

cylinder weighs between 52 to 64 kg. Depending on the capacity of cylinder. With 50 litres.

Capacity has a 316 mm dia and is 850 mm length, while those with 65 liters capacity have a

316 mm dia and 1060 mm long.

TESTING:

CNG cylinders are tested to resist pressure up to 350 bar as against the working pressure of

200 bar. The cylinders are put through severe abused tests before being approved by the

Statutory authorities

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IDENTIFICATION:

CNG storage cylinders fitted in the vehicle should bear the name of the manufacturer, BIS

specifications, IS- 7285, Date of manufacture and testification, capacity, batch number, serial

number etc.

SPURIOUS CYLINDERS:

Spurious cylinders are not approved specified cylinders. They do not conform I.S. 7285.

They bears welding mark on their body. They are made of separate sheets. They are neither

manufactured by the authorized manufacturer nor testified.

CERTIFICATION OF CYLINDERS:

All CNG cylinders are certified by the Nagpur based Chief Controller of explosives under IS

7285 BIS before installation.

APPROVED CYLINDER MANUFACTURERS:

There are three approved manufacturers for CNG cylinders as per specification.

i. M/s Everest Kanto Cylinder Ltd., Tarapur.

ii. M/S Bharat Pumps & pressures India Ltd., Naini (Allahabad).

iii. M/S Maruti Koatsu Cylinders Ltd.. Halal (Gujrat)

In addition to above, CNG cylinders of the following foreign Companies conforming to NZS-

5454 1989 read with IS-7285 have been also approved by the Chief Controller of Explosives,

Nagpur.

i. M/S Fiber Industries, S.p.A. Italy

ii. M/S Argentile, S.A., Argentina.

iii. M/S Worthington Cylinders, G nb H, Australia.

iv. M/S UEF Chester field Cylinders, England

COST OF CYLINDERS :

The approximate cost of 65 ltrs. genuine cylinders varies from Rs. 10000-Rs. 15000, whereas,

it is Rs. 5000/- or so for spurious cylinders.

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SAFETY VALVE (Pressure relief device):

It shall be protected from dirt and water ingress and far from sources of ignition and heat in

the vehicle when the rubber component in the safety valve is substandard or not fitted

properly, leaks are bound to occur. Metal to metal interfaces can not be made leak proof

unless there is a rubber component (Gasket) in between. Further gasket and valves used in

CNG vehicles should be of standard quality and bear ISI/BIS specifications.

PRESSURE REGULATOR:

Components located down stream pressure regulator shall be protected from pressurization

due to regulation failure.

PIPE WORK:

Pipe work shall be laid if possible on the chassis in such a way that no damage from intrinsic

vibration occurs (resonance with engine vibration) and there are no friction points.

LEAKAGE CONTROL:

The vehicles CNG fueling system shall be tested for leakage. The cylinder and parts of the gas

system shall be in such a system so that any leaking or venting gas from the fueling system

does not enter the driver and the passenger compartment, boot or other spaces, which are not

sufficiently ventilated. Any gas shall be directed safely to the atmosphere.

MINIMISING RISK OF GAS IGNITION:

i. The ignition sources shall be minimized to prevent fire in a vehicle.

ii. Electric/Electronic components in gas light housing shall be suitable.

iii. The location of electric cables and mountings shall be design to protect against

ignition of potential leaking gas.

NOZZLES:

There are two types of nozzles: -

i. New Zea Land standard (NZS)- The smaller ones (which comes fitted with the kit).

ii. Natural gas vehicles-I (NGV-I) The big ones (known as NGV nozzles, in popular

parlance).

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NZS Nozzles fitted with auto rickshaws and cars were considered the cause of long filling

time due to their smaller size of in-let as compared to International Standards of NGV I fitted

nozzles as per IGL observations before the Supreme Court on 12.4.2001. Hence the court

ordered that the CNG-vehicles be fitted with NGVI nozzles at the initial stage, because

replacement of NZS nozzles with NGV-I nozzle is neither scientific nor economical. In

addition, NZS nozzles are in appropriate mainly because of frequent o-ring (rubber valves)

failures getting cracked or losened. Sometimes, it is as high as two to three valves every

minute. It happens this way the attendant insert the spout into the inlet nozzle of the vehicle.

After a while there is cracking sound followed by the hissing of gas leak. The man quickly

takes the nozzle out in his hand and replaces the rubber valve which happens due to pressure

and heat.

The main cause of long filling time of CNG vehicle is low pressure supply which needs

improvement and not only the cause of NZS nozzle.

MAINTENANCE/WORKSHOP:

i. Maintenance of CNG system is very important for effective and efficiency of the

vehicles.

ii. Cylinders, if genuine, are near fool proof, but despite that if the safety valve is not

closed properly, accident can occur. It is, thus, desirable to keep a watch on the safety

valve.

iii. To add injury to insult, the Explosives Act prohibits replacing empty gas cylinder in

the buses with retro-fitting one.

iv. CNG cylinders are got to be tested and certified for use after every five years.

v. Maintenance of the CNG kit is vital. If they are not maintained properly, they might

trigger mishap any time.

vi. CNG kit and cylinder be got tested from approved work shops having details for

cylinders, make number and retesting data etc.

vii. A system be devised so that vehicles going to filling stations would be checked for a

safety norms. No doubt this may require extra two to five minutes but this is required

till the operators are conversant and aware of the CNG routine maintenance.

viii. Approved work shops be developed in the entire city for attending CNG run vehicles.

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EMISSION NORMS:

The current CNG regulations only require that converted buses should meet the emission

standards meant for diesel/petrol vehicles of their year of manufacture as per notification

dated 9th Feb. 2001 of the Ministry of Road Transport and Highways. These standards need

revision because tighter emission standards for gaseous pollutants for converted as well as

retrofitted buses can be laid down.

COMPANIES AUTHORISED FOR CNG MODE VEHICLES:

The companies which are authorized by the Delhi Government for manufacturing new CNG

vehicles, retro figment and conversion to CNG mode for various types of vehicles along with

their cost for various jobs are given in table: I (Annexure). The cost of various jobs included

in the table I of the companies may needs correction on current market trends with reference

to companys notification.

INFRASTRUCTURE DEVELOPMENT FOR CNG RUN SYSTEM:

Indraprastha Gas Limited which is a joint venture company of Gas Authority of India (GAIL)

Ltd., Bharat Petroleum Corporation Ltd., and the Govt. of Delhi is the only company

responsible for supply of CNG for Delhi Transport System.

Infrastructure development for supply of CNG in the city of Delhi has a vital role for efficient

CNG transport system. Under distribution net work IGL set up Mother stations, on line

stations, Daughter booster stations, daughter stations for proper dispensing of CNG through

out Delhi. The purpose of these stations are briefly discussed hereunder: -

Mother Station: A station, which is attached to the gas pipe line and which delivers CNG at a

pressure of 250 Bar to Cascades.

On line Station: A station which is on line and has a smaller compressor to deliver CNG to

vehicles at 250 bar.

Daughter booster station: A daughter station with its own compressor (Booster).

Daughter station: A station which receives a cascades (CNG tank) from a Mother Station

The biggest compressors which are installed in mother stations have a flow rate of 1100 kg

per hour. For on line stations, a smaller compressor is used which can fill 250 kg per hour.

Both these compress the gas up to 250 bar pressure and can serve two dispensers at one time

i.e. they can help to fill up four vehicles at one time (one dispenser is used to fill two

vehicles). Therefore, lack of adequate number of compressors in a dispensing station can

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result in the dispensers becoming non-functional. There is an other type of compressor called

booster, which is used only in daughter station to increase the pressure of the gas, when

pressure in a Cascade drops to about 180 bar from the required filling pressure of 200 bar

while dispensing gas. In the absence of booster, it is not possible to dispense gas once the

pressure level falls to 180 bar and then this Cascade has to be changed.

A study done by IGL in Daughter Station without booster in Delhi connecting three wheelers

showed the following effect of low pressure with reference to filling of the cylinders

Pressure observedCNG filled in

kg

Filling time in

seconds

200 bar 3.5 (full) 90

180 bar 3.15 67

165 bar 2.89 48

150 bar 2.63 29

At the pressure of 150 bar it is not feasible to fill the cylinder any more and the Cascade is to

be changed and replaced with a new one. In other words, once the pressure drops in a Cascade

of a Daughter Station, very little gas gets filled up in the vehicles cylinders. It means that the

efficiency of the dispensing CNG at daughter station would depend on the number of cascade

available of adequate pressure. As learnt there are only 120-125 Cascades for 47 Daughter

Stations in Delhi @ approximate 3 Cascades for each Daughter Station. Out of these 3

Cascades only one Cascade is in use, other is getting filled up at Mother Station and the third

is in the transit. There are 74 dispensing stations for supply of CNG in Delhi, the location of

which is given in table 2 (Annexure).

Perusal of table 2 reveals that the distribution of dispensing stations is not spread out

uniformly in the NCT of Delhi. It is proposed to set up 50 more dispensing stations at the

existing petrol pumps where the land is available. By Sept. 2001 there is a proposal to increase

the dispensing stations from 74 to 87 and to convert 9 existing Daughter Stations into Mother

Stations. Implementation of the scheme in pipe line would give a great relief to the CNG

vehicle operation. There are ten CNG dispensing stations which are running on generators in

the lack of electric power. A polluting fuel is being used to supply non polluting fuel clearly

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shows the lack of planning. Now IGL is planning to purchase gas engine generated

mechanically compressors.

Along with infrastructure development, the Ministry of Petroleum and Natural Gas, Govt. of

India has to increase the allocation of natural gas for meeting the demand of CNG transport of

Delhi, so that, there is no deficiency of CNG for smooth and efficient running of transport

system of Delhi.

HOW ULSD IS ENVIRONMENTALLY ACCEPTABLE:

Diesel supply in Delhi has 0.05% sulphur content. Although, it meets Euro II standards, but it

is not defined as environmentally acceptable fuel.ULSD (Ultra-Low- Sulphur- Diesel) with

0.003-0.001 % of sulphur content, when used with exhaust fitments like Catalytic-

Regeneration-Trap (CRT) Gadget similar to a catalytic converter, which cost much more, is an

environmentally acceptable fuel. A major problem in use of the ULSD is that the adulteration

can not be ruled out in this fuel which makes the ULSD environmentally unacceptable. As of

now ULSD is not available in the country, then, either we have to import or upgrade the

existing refineries. India being a developing country is neither in a position to develop the

advance technology for upgrading its refineries to be able to produce ULSD nor the capacity

to import from the other countries.

IS THERE ANY CLEAN FUEL:

According to Sh. Bhurey Lal Committees report, submitted to the Honble Supreme Court in

July 2001, Electricity is the only clean fuel, whereas, CNG, LPG and Propane gas fuels are

categorized as environmentally acceptable fuels.

Conventional hydro carbon fuels are inherently polluting. Be it CNG, LPG, Diesel or Petrol.

These can not be regarded as clean fuel, as they produce exhaust emissions. Among these

hydrocarbon fuels, (CNG, LPG and Propane) are much less polluting then long chain

hydrocarbon fuel (Diesel and Petrol). Short chain hydrocarbon fuels have a lesser percentage

of carbon as compared to long chain counterparts.

CNG has one carbon atom while LPG has up to three carbon atoms. Diesel and petrol have as

many as 17-18 carbon atoms, which makes them more polluting then these gaseous fuels.

There are some confusion that CNG emits even finer particles then diesel, which have greater

propensity to enter the lungs which are dangerous. It is added that particles come from all

kinds of combustion sources. It is the toxicity of particulate emissions that help to prioritize

the control of emissions. Particulate emissions from diesel vehicles are tiny and are quoted

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with extremely toxic chemicals called polycyclic, aromatic hydrocarbons (PAH). Some of

which are known to be the most caricinogenous. Compared with diesel vehicles, CNG

vehicles emit negligible amount of particles. Moreover, even this little particle that are emitted

by CNG vehicles are not as toxic as particles emitted by diesel vehicles as CNG is composed

of mainly methane gas (CH4).

ULSD is also environmentally acceptable fuel with 0.003-0.001 % of sulphur content, which

is not available in the country and its production is also not feasible.

In view of the above, CNG is considered more cleaner then other gaseous fuel and is also

environmentally acceptable.

BENEFIT OF SINGLE FUEL:

Some sections of the transporters/operators are of the view that multi fuel/bi-fuel vehicles be

allowed which is not considered desirable.

Some dedicated (single fuel) vehicles can be optimized to take advantage of the unique

attribute of the particular fuel resulting in fewer emissions, more power and less cost, a quick

transition to single fuel vehicle would be highly superior to prolong reliance on inherently

interior multi fuel vehicles.

CONCLUSIONS:

Delhi is one of the most polluted City in the world, where over 3000 metric tonne air

pollutants are emitted every day. The strictest feasible emissions control can not substantially

reduce the alarming situations till the petroleum is used as a transport fuel.

There is no clean fuel except electricity. CNG, LPG and Propane are gaseous fuels and

environmentally acceptable.CNG is totally safe. It is non-toxic, non-corrosive and non-

carcinogenic (totally free from cancer inducing agents). It is cheap and easily available due to

availability of HBJ gas pipeline. Petroleum vehicles can be easily and effectively converted to

CNG mode vehicles. India is the first country in the world, which has succeeded for

conversion of diesel engine to CNG mode.CNG and LPG are the legal transport fuel

gases.CNG technology with distributor based ignition system is a first generation system,

which is an obsolete technology and dangerous. CNG advance technology is third generation

distributor less ignition system, which is computer-controlled system. There is an urgent need

to notify safety norms for CNG run vehicles otherwise the violators will go scot-free.

Emission standards for CNG run vehicles be finalized and notified at the earliest. For healthy

competition, there is a need to register and approve more manufacturers/companies for

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providing CNG run vehicles and their components. Infrastructure development for adequate

and efficient supply of CNG needs priority. Allocation for CNG be raised for NCR.ULSD

(Ultra Low Sulphur Diesel) is also an environmentally acceptable fuel if the sulphur content is

in between 0.003-0.001 % and when used with fitment. Its production on commercial basis is

uneconomical.

LIST OF MANUFACTURING COMPANIES AUTHORISED BY THE

GOVERNMENT

Company Vehicle type CNG Mode Cost

Ashok

Leyland

Bus Retrofit (I) Pre Euro Bus: Rs.5,98,320 (inclusive of

sales tax) Euro 1 Bus: Rs.6,88,338/

(Inclusive of sales tax)

Retrofitment labour charges: Rs.45-50,000

Bus CNG Chasis Rs.10,37,415 +sales tax of 1,24,439.80 (@

12%) = Rs.11,61,904.80 (Inclusive of sales

tax)

Telco Bus Retrofit(Company has

not yet started

retorfitment

work, this

proposal is in

pipeline

Rs.7,25,000 + Applicable tax in Delhi

Bus CNG Chasis Rs.10,29,000 + 1,23,480 (@ 12%) =

11,53,000 (according to Tata Sales and

Services, New Delhi)

Hindustan

Motors

RTV (mini

bus)

New CNG

vehicle

Rs.4,70,000 (on road HM RTV)

Bajaj Auto

Ltd

Auto New Rs.89,000 According to a Bajaj Auto Dealer

the CNG autos are only available through

replacement of old petrol autos at STA

office at Burari, Petrol autos are not sold inDelhi right now)

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Nugas

Technology

Ltd.

Bus Conversion Rs.4,86,000(inclusive of sales tax)

Rates Fuel &

Automobile

Technologies

Bus Conversion Rs.3,49,000 (inclusive of all tax)

VIP- Build

Con

Bus Conversion Rs.3,30,000 Type approval

Trans-Energy Taxi/Petrol

cars

Conversion Rs.35,440 (inclusive of sales tax)

Additional 10,000 for MPFI engine cars

Shrimankargas service

Auto Conversion Rs.22,700 (inclusive of sales tax)

DEVELOPMENT OF CNG INFRASTRUCTURE IN

DELHI (INDIA)

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SECTOR-WISE EMISSIONS* IN DELHI

(Metric Tonnes per Day)

With the increasing number of pollutants in Delhis air and with the background of increasing

trend in the use of CNG in the other parts of the world, Public Interest Litigation (PIL) was

filed in the Honble Supreme Court of India in 1985 seeking intervention in this matter. The

Honble Supreme Court had directed the Government of India to take initiative in promotingthe use of CNG, an established clean fuel in the world as transport fuel in Delhi to control the

increasing levels of ambient air pollution.

Formation of IGL:

Supreme Court gave directive to GAIL in July1998 to expand theCNG infrastructure

and to increase the number of CNG stationsfrom 9 to 80 by March 31, 2000 in Delhi. It also

directed Delhi Govt.to convert entire city bus fleet, autos & taxies from liquid fueltoCNG/Clean Fuel.

Subsequently in Dec.1998 Indraprastha Gas Limited (IGL) was incorporated as a joint

venture company of GAIL, BPCL & Govt. ofNCT of Delhi to regard to the CNG expansion

program in Delhi.

Issues of land allotment: Govt. of NCT of Delhi holding 5% equity in IGL helped IGL in

getting the allotment of lands, permissions for laying pipelines and in getting electricity

connections.

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Uncertainty on vehicles conversion: While IGL was formed to install 80 CNG stations

there was an apprehension whether the DTC buses would be available for CNG usage.

Besides all the autorikshaws, taxis and private buses were also to be converted for CNG use.

Tremendous efforts were required to convince DTC, Bus Operators and Delhi Administration

for the conversion of vehicles to CNG in such a short time. Today there are more than 87,000

vehicles in theNCT of Delhi, which are running on CNG.

Type of CNG Stations:

Four types of CNG stations have been developed in Delhi. These are as follows:

Mother Station: Mother stations are connected to the pipeline and have high compression

capacity. These stations supply CNG to both vehicles and daughter stations (through mobile

cascades). Typically they have the facility of filling all types of vehicles buses/autos/cars.

The Mother station requires heavy investment towards compressor, dispensers, cascades,

pipelines,tubing etc.

TYPICAL CNG MOTHER STATION

Online Station: CNG vehicle storage cylinders need to be filled at pressure of 200 bars. On

line Stations are equipped with a compressor of relatively small capacity, which compresses

low pressure pipeline gas to the pressure of 250 bar for dispensing CNG to the vehicle

cylinder. The investment in an online station is midway between daughter station and mother

station.

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Daughter Station: The Daughter Stations dispense CNG using mobile cascades. These

mobile cascades at daughter stations are replaced when pressure falls and pressure depleted

mobile cascade is refilled at the Mother Station. The investment in a daughter station is least

among all types of CNG stations

There is reduction in storage pressure at daughter stations with eachsuccessive filling. Once

the storage pressure drops, the refueling timeincreases, while the quantity of CNG dispensed

to vehicle also decreases.

Daughter-Booster Station: Installing a booster compressor can eliminate drawbacks of

daughter stations. The mobile cascade can be connected to the dispensing system through a

booster. Daughter booster (compressor) is designed to take variable suction pressure and

discharge at constant pressure of 200 bars to the vehicle being filled with CNG. The

investment in daughter booster station is slightly higher than that of

daughter station.

TYPICAL DAUGHTER BOOSTER STATION

Mega CNG Stations:

Mega CNG stations have been conceptualized to cater to a large fleet of

vehicles, particularly the buses. The objective is to provide comfortable filling experience to

the consumers when they come to the station forefeeling. Mega CNG stations are constructed

on much larger plot of land than that of conventional CNG stations, as a result of which more

number of Compressors and Dispensers can be installed and more number of vehicles can be

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simultaneously refuelled at such stations. A Mega CNG station has been commissioned at

Rohini, Sector 23 on July 13, 2003 and a similar station has been put into operation at

Patparganj on June 30, 2003.At present, there are three Mega CNG stations in Delhi. The

CNG Mega station at Patpargang has been constructed at a cost of around Rs.13.5 crores

cng project

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