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:

1. Switching to LPG takes two to three days of work and costs from about £1,400.
2. The gas tank is usually fitted in the boot of cars and in or beneath the freight compartment on commercial vehicles.
3.  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.
4. Compressed natural gas (CNG) can also be used to power vehicles, although the two systems are not compatible.
5. A compression unit is being developed which could make it possible for motorists to fill up overnight from their domestic gas supply.
6. 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.