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Natural gas, which is primarily composed of methane and ethane, is used for a variety of purposes, including heating and cooking, as well as for power generation (gas turbines). Natural gas can be liquefied for transportation purposes by applying pressure and cooling to it (LNG = liquefied natural gas). The Sultanate of Oman, for example, exports the vast majority of its natural gas in the form of liquefied natural gas (LNG), as evidenced by the Qalhat LNG plant, which has the capacity to liquefy 6.6 million tonnes of natural gas per year. At oil refineries, fractional distillation is used to separate crude oil into its constituents. The different “fractions” of crude oil have different boiling points and are primarily composed of alkanes with similar chain lengths, which is a characteristic of crude oil (the higher the boiling point the more carbon atoms the components of a particular fraction contain – see the list of alkanes for details about the boiling points).
various crude oil fractions:
C3-C4
When liquefied at low pressures, propane and butane can be used in a variety of applications, such as in the propane gas burner or as propellants in aerosol sprays, among other things. Butane is a fuel that is used in cigarette lighters (where the pressure at room temperature is about 2 bar).
C5-C8
The alkanes, which range from pentane to octane in boiling point, are highly volatile liquids that are excellent solvents for nonpolar substances. The fuels that they contain are used in internal combustion engines.
C9-C16
Alkanes, ranging from nonane to hexadecane, are viscous liquids that are used in diesel and aviation fuel, among other applications (kerosene). Low temperatures and polar regions can be affected by the higher melting points of these alkanes, as the fuel becomes too viscous as a result of the higher melting points.
C17-C35
Alkanes with carbon atoms ranging from 17 to 35 are the primary constituents of lubricating oil. They also have anti-corrosive properties due to the fact that their hydrophobic nature prevents the metal surface from coming into contact with water. Solid alkanes are also used in the production of paraffin wax, which is used in candles.
Bitumen contains alkanes with a chain length greater than 35 carbon atoms, which are known as >C35 alkanes (as it is used in road surfacing). Due to the low chemical and commercial value of these higher alkanes, they are typically cracked down to lower alkanes to be used as fuel
(1) At high pressures and low temperatures, methane can co-crystallize with water, resulting in the formation of a solid methane hydrate. The energy content of the known submarine methane hydrate fields outpaces the combined energy content of all known natural gas and oil deposits combined.
Paraffin wax should not be confused with true animal or plant wax, which is composed of carboxylic acid and alcohol esters of various carboxylic acids or alcohols.
What are the effects of the alkanes?
- Because there are no functional groups present in alkanes, they are generally considered to be non-reactive compounds.
- Alkanes and other hydrocarbons, on the other hand, are most likely responsible for the existence of life on Earth.
- According to the hypothesis advanced by Nobel laureates Harold Urey and Stanley Miller in their famous Urey-Miller experiment in 1953, amino acids, which are the building blocks of life on Earth, could have been produced by the reactions of methane, ammonia, water, and hydrogen. During the experiment, Miller generated an electrical spark in a mixture of gaseous molecules, which he used to extract minute amounts of amino acids later on. Despite the fact that other hypotheses later challenged this hypothesis of the origin of life, the experiment itself served as an inspiration for further investigation into the origin of life.
- Alkanes can be found in a wide variety of organisms. Ants and cockroaches have n-undecane in their bodies, which is a pheromone that attracts other insects. Cockroaches are more likely to congregate if this is the case.
- When ants sting, it is hypothesised that the alkanes aid in the spread of formic acid through the victim’s contact point.
- Pristane can be found in shark liver oil, as well as in sperm whale, lobster, and zooplankton, among other things. As a result of its apparent stability under anaerobic conditions, it is a useful biological marker that has been used in a variety of medical studies.
The application of alkanes in everyday life
Alkanes are used in the production of petroleum
the various fractions of crude oil and how they are used. Let’s take a look at a couple of the most important aspects of petroleum in our daily lives. The following link will take you to an interactive programme on the use of petroleum.
Crude oil is refined in a refinery
A refined product is required not only to remove the dark colour and foul smell from crude oil, but also to eliminate the presence of sulphur compounds that reduce the response of gasoline to anti-knock agents such as tetraethyl lead (now not recommended). After fractional distillation, crude oil is refined to remove impurities.
The octane number is the number of revolutions per minute
This number represents the performance of a given fuel in terms of its use as a motor or aviation fuel. A fuel’s octane number indicates how much compression it can withstand. The higher the number, the better. The use of fuel with a lower octane number can result in knocking-related problems. During knocking, the engine can suffer severe damage and may even become fatal if all of the fuel, instead of burning smoothly, explodes at a specific portion of the engine.
Historically, it has been discovered that iso-octane can increase the ability of a fuel to withstand compression, and as a result, an arbitrary octane number of 100 has been assigned to it. It was discovered that n-heptane detonates readily and was assigned an octane number of zero. The presence of iso-octane in the fuel does not imply that the fuel has a high octane number. An example of this would be a test engine in which the octane number of a fuel under consideration is assigned based on its anti-knocking properties in comparison to a mixture of iso-octane and n-hexane. We can tell by the octane number of a fuel that it has the same anti-knocking ability as a mixture consisting of 95 percent iso-octane and 5 percent n-heptane, which is what we want (percentage calculated by volume). Alkanes are commonly found in natural gas and are used in a variety of applications.
Natural gas contains lighter alkanes (primarily methane, ethane, propane, and butane) and emits fewer pollutants than petroleum-derived fuels, making it a more environmentally friendly alternative.
->house that is heated and cooled (air conditioning)
->oven
->fireplaces
->lights for the outdoors
->Fuel cells are a type of battery.
->products made of plastic (from cracking of ethane, propane)
Fertilizer is a term used to describe a substance that provides nutrients to plants (in Haber-Bosch process for production of ammonia, hydrogen comes from methane)
Fabric
anti-freeze
Motor fuel [compressed natural gas (CNG) or liquefied natural gas (LNG) is less polluting and more affordable than gasoline]
Biogas
Anaerobic digestion or fermentation of renewable materials such as manure, crops, sewage, farm waste, municipal waste, and other organic waste results in the production of biogas as an alternative fuel. Biogas is primarily composed of methane and carbon dioxide, but it also contains other elements such as hydrogen, nitrogen, oxygen, and hydrogen sulfide15. Numerous rural households in India are utilising biogas as a fuel source16.
Diesel that is made from renewable resources
Conclusion
The term “renewable diesel” refers to diesel that is produced from renewable resources such as vegetable oil or fat under high temperatures, pressures, and the presence of a catalyst, as opposed to “petrodiesel.”
It is also referred to as “green diesel” due to the fact that it does not contain sulphur or other toxic substances. Alkanes containing 9-18 carbon atoms can be found in renewable diesel.
