Compressed Natural Gas (CNG) | Composition, Advantages, Disadvantages

What is Compressed Natural Gas?

Natural gas is a fossil fuel which is usually formed in the Earth along with petroleum. Its main constituent is methane. It also contains small quantities of Ethane and Propane. It is liquefied by compression. CNG is used as a fuel in automobiles, houses and factories. It is also used as a source of hydrogen in the manufacturing of fertilizers.

Composition of CNG

Compressed Natural Gas is generally a mixture of the lighter hydrocarbons with methane (CH₄) predominating, often with varying fractions of nitrogen and impurities such as hydrogen sulfide.

Applications of CNG

1. It is used in Power generation
2. It is taken in domestic use for cooking food etc.
3. It is used in transportation sector
4. It is also used in manufacturing of fertilizers

Here are some advantages and disadvantages of Natural gas

Advantages of CNG

1. It has Octane number around 110, which makes it an excellent SI (spark ignition) engine fuel. Because of high octane number flame speed is higher and it can operate with high compression ratios.
2. It has low engine emissions. low aldehyde emission than alcohols.
3. It is fairly abundant in nature and also can be obtained from coal.
4. It’s environment friendly.
5. It is safer and easier to store, by far.
6. It is reliable.
7. It’s less costly compared to other fossil fuel energy sources.
8. Vehicles fueled with natural gas require less maintenance.
9. Vehicles fueled with natural gas have more life of lubricating oil. Reason being, no crankcase dilution.
10. It mixes evenly and easily with air.

Disadvantages of CNG

1. Its low energy density results in low engine performance
2. It has low engine volumetric efficiency because of gaseous fuel
3. It needs large storage tanks, which is a safety concern
4. It has Inconsistent fuel properties
5. Its refueling is a slow process
6. It’s highly combustible
7. It is non-renewable energy source
8. It emits some quantity of greenhouse gases

Featured Image Source: By Mariordo Mario Roberto Duran Ortiz – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=5833972