REPORT ON CNG
VEHICLES
Introduction:
Technology has not just made our work
easy but also brought a revolution in the lifestyle of mankind. In the thirst
of development and to meet the demands of tremendously increasing population,
we are depleting the resources that are non renewable for which sustainable
development is the only solution. Transportation
sector is one among the factors that demands maximum amount of fossil fuels.
So, looking for alternative fuels and commercially utilizing them is important.
Compressed Natural Gas (CNG) is an alternate fuel which is being used globally.
Analogue
of CNG:
CNG (Compressed natural gas) is a fossil fuel substitute for gasoline (petrol), Diesel fuel and propane/LPG. Although CNG's combustion does
produce greenhouse
gases, it is widely considered a more environmentally
"clean" alternative to conventional fuels. It is much safer than
other fuels in the event of a spill,
because natural gas is lighter than air and disperses quickly when released.
CNG may also be mixed with biogas (which can be produced from landfills or wastewater).
Composition
of CNG:
CNG is made by compressing natural gas (which is mainly composed of methane,
CH4), to less than 1 percent of the volume it occupies at standard atmospheric pressure. It is
stored and distributed in hard containers at a pressure of 200–248 bar
(2,900–3,600 psi), usually in cylindrical or spherical shapes.
CNG
usage:
CNG is used in traditional gasoline/internal combustion engine automobiles that have been converted
into bi-fuel
vehicles (gasoline/CNG). Natural gas vehicles are increasingly used in Iran, the Asia-Pacific region (especially Pakistan and the Indian capital of Delhi), and other large cities
like Ahmadabad, Mumbai, Kolkata, Chennai—as
well as cities such as Lucknow, Kanpur, etc. Its use is also increasing in Latin America, Europe and North America because of rising gasoline prices.
Initiation of CNG usage in the country:
The Delhi
authorities have complied with an order to withdraw from service thousands of
buses over eight years old - half the city's fleet - despite a plea from
transport operators.
The old buses, which run on unrefined diesel, are seen as a major source of
pollution. They are to be replaced by vehicles using more
environmentally-friendly compressed natural gas. The
Delhi transport commissioner, Parvez Hashmi, said measures would be introduced
within a few days to help counter inconvenience to commuters.
These would include
diverting about 1,000 buses from inter-state services to serve the city, and
issuing tenders to run some 1,500 buses to private operators. In its
application to the court on Friday, Delhi's transport corporation had requested
until 2005 to implement the ruling, issued two years ago. But
the court said it had given fair warning, and told the corporation that it
could not afford to let it continue to pollute the city's air.
Taking the green
route:
- Switching to LPG takes two to
three days of work and costs from about £1,400.
- The gas tank is usually fitted
in the boot of cars and in or beneath the freight compartment on
commercial vehicles.
- The most common set-up is a bi-fuel
system, where a dashboard-mounted switch can change from one fuel to the
other, even when the vehicle is in motion.
- Compressed natural gas (CNG)
can also be used to power vehicles, although the two systems are not
compatible.
- A compression unit is being developed which could make it possible for motorists to fill up overnight from their domestic gas supply.
- Re-fuelling
is the same as using a petrol pump
Benefits of using a CNG:
Safer:
- CNG does not contain any lead,
thereby eliminating fouling of spark plugs.
- CNG being
lighter than air disperses in case of an accident, which is a far safer concept
than with flammable liquid fuel.
- CNG is unlikely to ignite for
hot surfaces, because of its high auto-ignition temperature (540 °C), and
the range of its flammability is very narrow (5 - 15 %).
- CNG produces up to 95% less
carbon monoxide compared to gasoline and petrol.
Adaptability
of CNG:
·
The cost of conversion is a barrier to
wider/quicker adoption of CNG as a fuel. It is also why municipal government,
public transportation vehicles were the most visible early adopters of it, as
they can more quickly amortize the money invested in the new (and usually
cheaper) fuel.
Better efficiency:
- In contrast to
a regular gasoline-powered car, which averages 32 miles per gallon, a
CNG-powered car averages 43 miles per gallon
- As CNG is a gaseous fuel, it
mixes easily and evenly in air, thus adding to the fuel efficiency.
Low deterioration:
- CNG emits significantly less
pollutants (e.g., carbon dioxide, unburned hydrocarbons, carbon monoxide,
oxides of Sulphur and Nitrogen; particulate matter than petrol.) For
example, an engine using petrol for 100 km emits 22 kilograms of CO2,
while for the same distance CNG powered engine emits only 16.3 kilograms
of CO2.
- For the same amount of energy,
CNG produces nearly 40 percent less CO2.
- Carbon monoxide emissions are
reduced. Due to lower carbon dioxide and nitrogen oxides emissions, CNG is
the better choice to reduce greenhouse gas emissions.
Highly economical:
- The CNG prices change less
frequently as compared to Gasoline.
- Cost of CNG is generally 15% to
40% less than that of gasoline or diesel. Increase in the popularity and
production of CNG vehicles can lead to decrease in the cost of vehicles.
Low maintenance:
- Neither Lead nor benzene is
present in CNG; so, fouling of lead in spark plugs is eliminated.
- Lower maintenance costs than
other hydrocarbon-fuel-powered vehicles.
- Life of lubricating oils can
increase as crankcase oil is not contaminated or diluted by CNG.
Summary:
To sum up, for a better
society change should come. That better change is changing to CNG vehicles.
References:
CNG - WIKKIPEDIA,
CNG - BBC News.
