cng project
Post on 29-May-2018
275 Views
Preview:
TRANSCRIPT
-
8/9/2019 Cng Project
1/66
-
8/9/2019 Cng Project
2/66
Potential of CNG as a fuel for vehicles
2
-
8/9/2019 Cng Project
3/66
Potential of CNG as a fuel for vehicles
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.
3
-
8/9/2019 Cng Project
4/66
Potential of CNG as a fuel for vehicles
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.
4
-
8/9/2019 Cng Project
5/66
Potential of CNG as a fuel for vehicles
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).
5
-
8/9/2019 Cng Project
6/66
Potential of CNG as a fuel for vehicles
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
6
-
8/9/2019 Cng Project
7/66
-
8/9/2019 Cng Project
8/66
Potential of CNG as a fuel for vehicles
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
8
-
8/9/2019 Cng Project
9/66
Potential of CNG as a fuel for vehicles
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.
9
-
8/9/2019 Cng Project
10/66
Potential of CNG as a fuel for vehicles
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
10
-
8/9/2019 Cng Project
11/66
Potential of CNG as a fuel for vehicles
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-
11
-
8/9/2019 Cng Project
12/66
Potential of CNG as a fuel for vehicles
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
12
-
8/9/2019 Cng Project
13/66
Potential of CNG as a fuel for vehicles
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
13
-
8/9/2019 Cng Project
14/66
Potential of CNG as a fuel for vehicles
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
14
-
8/9/2019 Cng Project
15/66
Potential of CNG as a fuel for vehicles
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
15
-
8/9/2019 Cng Project
16/66
Potential of CNG as a fuel for vehicles
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.
16
-
8/9/2019 Cng Project
17/66
Potential of CNG as a fuel for vehicles
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
17
-
8/9/2019 Cng Project
18/66
Potential of CNG as a fuel for vehicles
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.
18
-
8/9/2019 Cng Project
19/66
Potential of CNG as a fuel for vehicles
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
19
-
8/9/2019 Cng Project
20/66
Potential of CNG as a fuel for vehicles
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
20
-
8/9/2019 Cng Project
21/66
Potential of CNG as a fuel for vehicles
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:
21
-
8/9/2019 Cng Project
22/66
Potential of CNG as a fuel for vehicles
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.
22
-
8/9/2019 Cng Project
23/66
Potential of CNG as a fuel for vehicles
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.
23
-
8/9/2019 Cng Project
24/66
Potential of CNG as a fuel for vehicles
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
24
-
8/9/2019 Cng Project
25/66
Potential of CNG as a fuel for vehicles
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
25
-
8/9/2019 Cng Project
26/66
Potential of CNG as a fuel for vehicles
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
26
-
8/9/2019 Cng Project
27/66
Potential of CNG as a fuel for vehicles
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
27
-
8/9/2019 Cng Project
28/66
Potential of CNG as a fuel for vehicles
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.
28
-
8/9/2019 Cng Project
29/66
Potential of CNG as a fuel for vehicles
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$. Assuming that the ratio between
imported fuels and domestic production will remain the same, as at present, and demand
growth will be as predicted by PSMP, the likely quantum of import of diesel alone will be
about 6700 thousand MT in 2015.
29
-
8/9/2019 Cng Project
30/66
Potential of CNG as a fuel for vehicles
Projected Imports of Diesel in Bangladesh
000MT
Year Diesel
1995-96 1007
2000 1621
2005 2610
2010 4206
2015 6775
Thus, considering the existing level of imports of these products and precarious position of
foreign exchange reserves, Bangladesh cannot afford to depend on imports of energy fuels to
meet the increasing demand.The other viable option is to replace the petrol and diesel by
natural gas as a fuel in industry and transport.For example, let us consider the case of
replacing use of imported diesel by domestically produced natural gas in the industry and
transport sector, and resulting foreign exchange savings. Since the replacement of diesel with
gas is a gradual process and takes few years to fully materialize, the savings in foreign
exchange will be smaller in the initial years. But after 4-5 years such savings will pick up.
Thus the import substitution may save the country foreign exchange to the tune of about US$
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
30
-
8/9/2019 Cng Project
31/66
Potential of CNG as a fuel for vehicles
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.
31
-
8/9/2019 Cng Project
32/66
Potential of CNG as a fuel for vehicles
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.
32
-
8/9/2019 Cng Project
33/66
Potential of CNG as a fuel for vehicles
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
33
-
8/9/2019 Cng Project
34/66
Potential of CNG as a fuel for vehicles
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.
34
-
8/9/2019 Cng Project
35/66
Potential of CNG as a fuel for vehicles
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
35
-
8/9/2019 Cng Project
36/66
Potential of CNG as a fuel for vehicles
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.
36
-
8/9/2019 Cng Project
37/66
Potential of CNG as a fuel for vehicles
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).
37
-
8/9/2019 Cng Project
38/66
Potential of CNG as a fuel for vehicles
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.
38
-
8/9/2019 Cng Project
39/66
Potential of CNG as a fuel for vehicles
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
39
-
8/9/2019 Cng Project
40/66
Potential of CNG as a fuel for vehicles
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
40
-
8/9/2019 Cng Project
41/66
Potential of CNG as a fuel for vehicles
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
41
-
8/9/2019 Cng Project
42/66
Potential of CNG as a fuel for vehicles
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
42
-
8/9/2019 Cng Project
43/66
Potential of CNG as a fuel for vehicles
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)
43
-
8/9/2019 Cng Project
44/66
Potential of CNG as a fuel for vehicles
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)
44
-
8/9/2019 Cng Project
45/66
Potential of CNG as a fuel for vehicles
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.
45
-
8/9/2019 Cng Project
46/66
Potential of CNG as a fuel for vehicles
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.
46
-
8/9/2019 Cng Project
47/66
Potential of CNG as a fuel for vehicles
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
47
-
8/9/2019 Cng Project
48/66
Potential of CNG as a fuel for vehicles
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
top related