Understanding the Difference: CNG, LPG and LNG

Natural gas comprises methane, whereas LPG (also known as liquefied petroleum gases) contains propane and butane (bottled gas). Rather than natural gas transported via pipeline, the gas bottles provide LPG.

Because LPG has a higher calorific value, commonly known as energy, it takes less gas to produce the same amount of heat. The oxygen-to-gas ratio required for optimal combustion is another significant distinction. The oxygen-to-gas ratio for LPG should be around 25 to 1. A 10:1 ratio is required for natural gas.

LPG is better than natural gas since it contains more energy and is available all around the world. Natural gas is more efficient than LPG in terms of pipe transport and also in terms of carbon dioxide emissions when burned. 

When comparing LPG to natural gas, propane is heavier than air and can settle. In contrast, natural gas is lighter than air and will evaporate more quickly if there is a problem, which could be a security advantage over LPG.

In a nutshell, the key differences between LPG and natural gas are their energy contents, storage density, transportation methods, and the amount of air required for optimal burning. Propane is not the same as natural gas.

LPG gas is not the same as natural gas, even though both are combustible hydrocarbon gases. However, you can use them for a lot of the same things. Let’s also take a look at the comparison between CNG and LPG.

LPG vs LNG vs CNG

• Liquefied Natural Gas (LNG) is natural gas (Methane) that has been cryogenically liquefied. Natural gas cooled to a liquid condition (liquefied) at roughly -260° Fahrenheit for shipping and storage is known as liquefied natural gas (LNG).
• In a natural gas pipeline, the volume of liquid natural gas is around 600 times smaller than that of gaseous natural gas.
• LPG Liquefied Petroleum Gas is mostly butane and propane liquefied under pressure, either separately or in combination.
• Natural gas and crude oil refining methods both create LPG. CNG, commonly known as compressed natural gas, is a natural gas that has been compressed and stored at high pressure.
• Because natural gas (Methane) is much lighter than air, it will often disperse in the event of a leak. In terms of safety, this is an advantage over LPG.
• In the case of LPG vs LNG, unlike LNG, which is liquefied cryogenically, it is conceivable to employ a low pressure to produce LPG. Normal temperatures and pressure are present in both gases (NTP).
• Tanks or cylinders are used to store, transport, and distribute LNG. LNG is stored, transported, and stored in specially built cryogenic tanks before being dispersed via pipelines following regasification.
• LNG – Liquefied Natural Gas – is natural gas (Methane) that is cryogenically liquefied at 161 degrees Celsius and then stored in tanks when weighing LNG as an alternative for LPG and CNG.
• LPG is propane that has been liquefied inside cylinders at moderate pressure. Compressed Natural Gas (CNG) is a cylinder of highly compressed natural gas (Methane). At NTP, everything is gas.

What’s More?

Following regasification, LNG is stored and transported into cryogenic tanks before being transported via pipes. LNG and CNG are two gases that can be stored and transported in cylindrical containers.

CNG (compressed natural gas) is a highly compressed natural gas stored in cylindrical canisters. At 20°C or 1.25 atm (NTP), LPG, propane, and butane are all gases that liquefy at low pressure. Under pressure, methane will remain a gas. LNG is only cryogenically liquefied.

Methane also has a high autoignition temperature of 537 degrees Celsius (999degF). Propane also has a 477°C auto-ignition temperature (878degF).

Do you know, CNG is good for the environment because it emits fewer pollutants. CNG is one of the most environmentally friendly fuels available. Carbon monoxide emissions are reduced by 90 to 97% when CNG is used. 

Changing one truck from diesel to natural gas reduces pollution by the same amount as removing 325 automobiles from the road. Natural gas, rather than diesel or gasoline, helps minimise small soot particles that can aggravate asthma and other respiratory problems.

The temperature at which auto-ignition occurs is the lowest temperature at which the substance spontaneously ignites in the air without the presence of an external source of ignition.

Propane will be more explosive than methane based on its relative autoignition temperatures because it ignites spontaneously at a lower temperature.

	Propane	Methane
Chemical Formula	C3H8	CH4
Energy Content: MJ/m3	93.2	38.7
Energy Content: MJ/kg	49.58	52.5
Energy Content: Btu/ft3	2572	1011
Flame Temp: Fº	3573	3542
Specific Gravity	1.5219	0.5537
Gas Volume: m3/kg	0.540	1.499

The ratio of the object’s density to the substance used as a reference is referred to as specific gravity. In addition, the specific gravity of an object can determine whether it will sink or float in the reference material. It is water, dense at one millimetre per cubic centimetre, or one millimetre per gram, and reference material.

In layman’s terms, specific gravity is the factor that determines whether items will sink or float in water.

An object’s density is a measurement of how heavy or dense it is within a certain volume.

We also use mass per volume units to quantify it. Apart from that, it’s measured in cubic centimetres (g/cm3), millimetres (g/mL), or kilograms per litre (kg/L).

Simply explained, density is the amount of weight or lightness contained within a particular volume of an object. Furthermore, the weight of an object is precisely proportional to its density. This means that an object with more molecules has a higher density, whereas fewer molecules have a lower density.

What is the Formula to Learn it the Simplest Way?

Density is defined as the ratio of mass to volume.

The density of an object, such as water, is defined by its specific gravity (taking water as a reference)

Conclusion

The contrast between PNG and LPG is comparable to that between natural gas and LPG. PNG stands for propane and isobutane, whereas LPG stands for propane and isobutane, or a combination of the three. The other distinctions, such as those noted above, remain the same.