Differences between liquefied petroleum gas (LPG) and compressed natural gas (CNG)

Liquefied Petroleum Gas or LPG is a name well known to everyone, as it is known as the cooking gas. It is one of the natural gases that can be obtained as a by-product of natural gas processing and petroleum refining. It is composed of butane, propane and butylene. Compressed Natural Gas or CNG is a gas widely used in automobiles, and it is also a natural gas obtained from methane wells, coal fields. It is composed of methane.

These natural gases are easily distributed over long distances through pipelines, and are more economical than diesel and gasoline. LPG and CNG have a wide range of applications, such as in industries, automobiles, as a cooking fuel, refrigerant, etc. However, these gases release greenhouse gases (CO2 and CO) but in smaller quantities than gasoline.

Deep below the surface, natural gas is found, these are called reservoirs. Millions of years ago, when marine plants and animals died and sank to the bottom of the sea, they were buried under sedimentary rocks by the natural process. Gradually, with time, intense pressure and heat, these dead matters were transformed and turned into a gas, and that is natural gas.

Natural gas has many different compounds, and methane (CH4) is found in the largest amount, apart from this, it (natural gas) also contains hydrocarbon gas liquids, natural gas liquids and other non-hydrocarbon gases. With this, we will be learning about the general differences between LPG and CNG, along with a brief description of the same followed by the key differences about the same.

Comparison Chart

Definition of Liquefied Petroleum Gas (LPG).

LPG is also known as autogas. Propane or butane is another name for Liquefied Petroleum Gas or LPG. This gas is highly flammable and is heavier than air; it settles to the bottom of the surface.

LPG is composed of several hydrocarbon gases. It is widely available throughout the world and is considered to be the most efficient and readily available fuel at economical prices.

LPG is mainly used as a fuel for heating cooking appliances, fuel for automobiles and also in some other industries. These are produced as a by-product of petroleum refining and natural gas processing. It is filled into pressurized cylinders and shipped for transportation or storage.

A foul odor, which we can perceive is that of mercaptans, a substance that is introduced into such gas cylinders so that it can be easily recognized in case of any leakage.

Definition of Compressed Natural Gas (CNG)

Compressed Natural Gas (CNG) also known as ” clean fuel “CNG is compressed methane gas (CH4) at a pressure of 200 to 248 bar. CNG is cheaper than LPG. It is a non-pollutant, which creates a clean fuel and causes no harm to the atmosphere.

CNG is obtained from coal beds, methane wells, oil wells and natural gas wells. This gas is produced by compressing natural gas composed of CH4 and methane. LPG is also stored in hard containers such as cylinders at a pressure of 20-25 MPa.

Compared to gasoline and diesel, CNG is available at a lower price, so it is considered a good sign for the owner of a four-wheeler to switch to this clean or pollutant-free fuel from diesel or gasoline. CNG emits a much lower amount of greenhouse gases than LPG, which produces carbon dioxide. carbon dioxidealthough both are cleaner than compared to gasoline.

Key differences between liquefied petroleum gas (LPG) and compressed natural gas (CNG).

The following are points showing the general differences between the two types of natural gases:

1. Liquefied petroleum gas (LPG). y compressed natural gas (CNG) are the types of natural gases; LPG is highly flammable and is obtained from a gas field reservoir, while CNG has less ignition compared to LPG and is obtained from coal wells, oil wells, etc.
2. LPG is extracted from a gas field reservoir. It is the by-product of one of the processes during the refining of crude oil; on the other hand, CNG is a natural gas obtained from coal beds, methane wells, oil wells and natural gas wells.
3. LPG, which is heavier than air, accumulates easily in low areas and is highly flammable; However, CNG is lighter than air and does not accumulate or disperse easily.
4. LPG contains Propane and Butane and has a calorific value of 90 to 95 MJ/m3; whereas CNG contains methane and has a low calorific value 35 to 40 MJ/m3.
5. LPG releases CO2 (one of the greenhouse gases), while CNG also releases a greenhouse gas. greenhouse gasbut in smaller quantities.
6. During use, great care must be taken as LPG is highly flammable and does not disperse easily; on the other hand, CNG has less risk of ignition as it is dispersible.
7. LPG is commonly known as cooking gas and is widely used in homes and restaurants for cooking. In contrast, CNG is used industrially, as a refrigerant and also as a fuel for automobiles.

Similarities between liquefied gas

Similarities between liquefied petroleum gas and compressed natural gas.

1. LPG and CNG are natural gases that are used both domestically and industrially. They are also used as fuel for automobiles.
2. These gases are used as transpondible fuels because they are stored in cylinders.
3. Compared to diesel and gasoline, they have reduced greenhouse gas emissions.

Conclusion

Earlier, LPG was considered as the clean fuel, but nowadays CNG is considered as the clean fuel and has replaced diesel and gasoline cars. But due to the nature of volatility, narrow flammability range and high autoignition temperature (540o C), CNG is not used as cooking gas. Therefore, LPG is still used and has maintained its importance by becoming useful and essential in cooking.

But, after such advantages and usefulness, these gases have the biggest disadvantage, and that is that they catch fire, and LPG ignites too fast compared to CNG. Therefore, care should be taken when using these gases.