Write note on Liquefied Petroleum Gas

LPG (Liquefied Petroleum Gas)

• LPG is generally manufactured from gas or the gas from the cracking units of petroleum refineries.
• LPG contains mainly of paraffinic hydrocarbons upto C₄ .
• Its main constituents are n-butane, iso-butane, propane and butylene.
• LPG exist as a gas in the atmospheric pressure and it can also be liquefied under pressure.
• LPG is normally free from moisture and H₂S , but contains traces of corrosive matters.
• To detect any leakage, it is usual to add tetrahydrothiophen to LPG, which even in traces can be detected by its smell.
• LPG is supplied under the trade name like Indane, Bharat gas, etc.
• Its average calorific value is about 27,800°kcal/m .
• The chemical composition of the two varieties of LPG is given below:

Advantages

1. The calorific value is roughly 3 times that of natural gas and 7 times that of coal gas. So, LPG has high efficiency and high heating rate.
2. Use of well designed, durable and neatly-constructed burners ensures complete combustion with no smoke.
3. It needs little care for maintenance purpose.
4. It is very flexible and easy to control.
5. Residue and oil contamination are small, as it burns cleanly.

Disadvantages

(i) Due to its faint odour, leakage cannot be easily detected.
(ii) Handling has to be done under pressure.
(iii) Its octane number is quite low and the load sensitivity is very high.

Uses:

(i) It is used as a domestic fuel due to high calorific value.
(ii) It is also called as kitchen gas or bottled gas.
(iii) LPG has been suggested as an alternative fuel for IC engines.
(iv) It is used as a direct motor fuel and as a source of petrochemicals.