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An Overview of Liquefied Petroleum Gas (LPG)

An Overview of Liquefied Petroleum Gas (LPG)

Liquid petroleum gas is produced by refining crude oil or natural gas. This article describes its production, properties, and utility in detail.
Poushali Ganguly
There are very few people who are not familiar with liquid petroleum gas (LPG). Most of the houses nowadays use LPG cylinders for cooking purposes, and of late, it is also being used as a fuel for vehicles, but very few know about it in detail. So, here we discuss the production, composition, uses, and advantages that it has, and the potential uses that it might have in future.

Production and Composition

LPG is obtained as a byproduct when refining crude oil or natural gas, and it is primarily composed of propane and butane with smaller amounts of propylene and butylenes. These belong to the category of hydrocarbons, and LPG has three or four hydrocarbon atoms. Apart from these hydrocarbons, there are negligible amounts of other hydrocarbons as well. Ethanethiol is combined with it for its characteristic smell so that leaks can be detected easily. Though these are the standard components, the percentage of each component differs from season to season. In summers, the percentage of butane is more than propane, and in winters, the percentage of propane is more than butane.

Due to its composition, which is rich in hydrocarbons, LPG evaporates at normal pressure and temperature; therefore, it is canned under pressure. It can be moved in cans and utilized in places far from the place of production, which makes it quite popular. The temperature at which it gets converted into the liquid form is called vapor pressure. To allow thermal expansion, the cans are not filled to the brim. Approximately 15% to 20% is kept empty so that even if the volume increases, it does not exert much pressure on the walls of the can.


LPG is used as a fuel in vehicles, for cooking, and also as a coolant of late so that the usage of chlorofluorocarbons can be avoided, which causes ozone layer depletion. Hydrocarbons as coolants in air conditioners at home or in vehicles are a good option since they are more energy efficient and need less pressure. But, there is always the risk of fire since it is highly flammable. So, it has to be used only with sufficient precautions by decreasing the chances of leakage and accidents. As a coolant, it is also very cheap and does not contribute to the greenhouse effect as well.

It is used as a cooking fuel in most of the houses of India and Brazil. It was quite popular as a cooking fuel in Hong Kong, but now the popularity has decreased. LPG is also used as a fuel for vehicles since the emissions are lesser than that of petrol or diesel.

Advantages and Disadvantages

There are many advantages such as, it is more environment-friendly, and the carbon content is lesser than other fuels. So, the carbon blocking engine parts in vehicles is also less. It also helps in increasing the longevity of the vehicle engine, thus, benefiting the owner of the vehicle.

The disadvantages are that it has a high risk factor due to its high flammability. Storage and safety should also be taken care of in the initial stages. Some engines and machines need the lubrication of oil, which it fails to provide. The other disadvantage is that the energy density of LPG is less than that of petrol and diesel. But, the tax on this fuel being less, it is cheaper. It is also very volatile and high chances of it vaporizing also remains.

LPG is a fossil fuel. It is non-renewable and would be exhausted one day. Therefore, it has to be used wisely.