Hydrocarbons have come to be the most common type of fuels, used in machines throughout the past century. Most machines have been designed to use the most efficient, and easy to get fuels available. On the same note, these hydrocarbons are also useful in domestic uses which include cooking. Hydrocarbons have been the most preferred source of fuel, because of their availability, minimal effects to the environment and safety associated with using them. Nowadays, liquefied natural gas (LNG) is preferred because of its chemical and physical properties, to other hydrocarbon fuels.
Chemical and Physical Properties
Liquefied natural gas is generally a colorless and odorless gas, which is changed into liquid form for easy transportation and use. However, in order to detect gas leaks, an odor substance is added at some point, when liquefying the gas. This ensures that any leakage can be detected easily through smelling (Tusian and Gordon 87). In addition, liquefied natural gas is not corrosive, is non-flammable as well as non-toxic. It is important to note that, this type of fuel is a fossil fuel and is composed of hydrogen and carbon compounds; hence it is categorized as a hydrogen carbon fuel. Natural gas is a mixture of various compounds majorly propane, ethane, methane and butane.
Additionally, this type of fuel also contains some impurities and other heavier hydrocarbons including: carbon dioxide, hydrogen and sulphur compounds (Hazlehurst 451). The boiling point of liquefied natural gas is usually -162oC, though this depends on the compounds present in the mixture. When burned in sufficient air, liquefied natural gas produces carbon dioxide and water vapor.
This is one quality that makes it non-toxic. On the contrary, if air supply is limited the gas can produce carbon monoxide gas which is toxic. The density of LNG also varies with its components, but is usually between 430kg/m3 and 470kg/m3. Its specific density is approximately 0.6 and is thus lighter than air. Liquefied natural gas has a very high ignition temperature, which is around 540oC thus making it non-flammable, contrary to natural gas which is flammable (Tusian and Gordon 88).
Storage and Mode of Transport
In its liquid form, LNG occupies a very small volume compared to the gaseous status, which makes it economical and cost effective to store it in a liquid state.
Additionally, liquefied natural gas cannot burn without air, making it impossible for combustion to take place in the cylinder (Hazlehurst 37). Therefore, LNG is commonly transported by way of intermodal tanks. It is important to note that, LNG is safe to use because besides the odor which ensures that any leakage is detected, it is not poisonous and does not produce poisonous products, during combustion.
Ifliquefied natural gas carried in a ship spills, it leads to a state known as localized overpressure.
This is due to the fact that, its boiling point is far much lower than earthly temperatures, and this causes a physical explosion when the liquid turns spontaneously into a gaseous state. This can be catastrophic at times, because the pressure rating of the cargo is low.
Liquefied natural gas has been put into use, both domestically and commercially. Domestically, LNG is used for cooking as well as lighting while in industries, it is used as a source of heat for various processes (Hazlehurst 469).
Hazlehurst, John. Tolley’s Basic Science and Practice of Gas Service. London: Routledge, 2012. Print.
Tusian, Michael, and Gordon Shearer. Lng: A Nontechnical Guide. Tulsa: Penn Well Books, 2007. Print.