Usage[edit]
Oil refineries are one way hydrocarbons are processed for use. Crude oil is processed in several stages to form desired hydrocarbons, used as fuel and in other products.
Hydrocarbons are a primary energy source for current civilizations. The predominant use of hydrocarbons is as a combustible fuel source. In their solid form, hydrocarbons take the form of asphalt (bitumen).[13]
Mixtures of volatile hydrocarbons are now used in preference to the chlorofluorocarbons as a propellant for aerosol sprays, due to chlorofluorocarbon's impact on the ozone layer.
Methane [1C] and ethane [2C] are gaseous at ambient temperatures and cannot be readily liquefied by pressure alone. Propane [3C] is however easily liquefied, and exists in 'propane bottles' mostly as a liquid. Butane [4C] is so easily liquefied that it provides a safe, volatile fuel for small pocket lighters. Pentane [5C] is a clear liquid at room temperature, commonly used in chemistry and industry as a powerful nearly odorless solvent of waxes and high molecular weight organic compounds, including greases. Hexane [6C] is also a widely used non-polar, non-aromatic solvent, as well as a significant fraction of common gasoline. The [6C] through [10C] alkanes, alkenes and isomeric cycloalkanes are the top components of gasoline, naphtha, jet fuel and specialized industrial solvent mixtures. With the progressive addition of carbon units, the simple non-ring structured hydrocarbons have higher viscosities, lubricating indices, boiling points, solidification temperatures, and deeper color. At the opposite extreme from [1C] methane lie the heavy tars that remain as the lowest fraction in a crude oil refining retort. They are collected and widely utilized as roofing compounds, pavement composition, wood preservatives (the creosote series) and as extremely high viscosity shear-resisting liquids.
Poisoning[edit]
Hydrocarbon poisoning such as that of benzene and petroleum usually occurs accidentally by inhalation or ingestion of these cytotoxic chemical compounds. Intravenous or subcutaneous injection of petroleum compounds with intent of suicide or abuse is an extraordinary event that can result in local damage or systemic toxicity such as tissue necrosis, abscess formation, respiratory system failure and partial damage to the kidneys, the brain and the nervous system. Moaddab and Eskandarlou report a case of chest wall necrosis and empyema resulting from attempting suicide by injection of petroleum into the pleural cavity.[14]
Reactions[edit]
There are three main types of reactions :
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Substitution Reaction
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Addition Reaction
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Combustion
Substitution Reaction[edit]
Substitution reaction only occur in saturated hydrocarbons (single carbon-carbon bonds). In this reaction, an alkane reacts with a chlorine molecule. One of the chlorine atoms displace an hydrogen atom. This forms hydrochloride acid as well as the hydrocarbon with one chlorine.
e.g. CH4 + Cl2 →CH3Cl + HCl
e.g. CH3Cl3 + Cl2 →CH2Cl2 + HCl
All the way until CCl4 (Carbon tetrachloride)
e.g. C2H6 + Cl2 →C2H5Cl1 + HCl
e.g. C2H4Cl2 + Cl2 →C2H4Cl3 + HCl
All the way until C2Cl4 (DiCarbon tetrachloride)
Addition Reaction[edit]
Addition reactions involve alkenes and alkynes. In this reaction a halogen molecule breaks the double or triple bond in the hydrocarbon and forms a bond.
Combustion[edit]
Container of ethanol vapour mixed with air, undergoing rapid combustion
Main article: Combustion
Hydrocarbons are currently the main source of the world’s electric energy and heat sources (such as home heating) because of the energy produced when burnt.[15] Often this energy is used directly as heat such as in home heaters, which use either petroleum or natural gas. The hydrocarbon is burnt and the heat is used to heat water, which is then circulated. A similar principle is used to create electric energy in power plants.
Common properties of hydrocarbons are the facts that they produce steam, carbon dioxide and heat during combustion and that oxygen is required for combustion to take place. The simplest hydrocarbon, methane, burns as follows:
CH4 + 2 O2 → 2 H2O + CO2 + Energy
In inadequate supply of air, CO gas and water vapour are formed:
2 CH4 + 3 O2 → 2CO + 4H2O
Another example of this reaction is propane:
C3H8 + 5 O2 → 4 H2O + 3 CO2 + Energy
CnH2n+2 + (3n+1)/2 O2 → (n+1) H2O + n CO2 + Energy
Burning of hydrocarbons is an example of an exothermic chemical reaction.
Hydrocarbons can also be burned with elemental fluorine, resulting in carbon tetrafluoride and hydrogen fluoride products
Petroleum[edit]
Main article: Petroleum
Natural oil spring in Korňa, Slovakia.
Extracted hydrocarbons in a liquid form are referred to as petroleum (literally "rock oil") or mineral oil, whereas hydrocarbons in a gaseous form are referred to as natural gas. Petroleum and natural gas are found in the Earth's subsurface with the tools of petroleum geology and are a significant source of fuel and raw materials for the production of organic chemicals.
The extraction of liquid hydrocarbon fuel from sedimentary basins is integral to modern energy development. Hydrocarbons are mined from oil sands and oil shale, and potentially extracted from sedimentary methane hydrates. These reserves require distillation and upgrading to produce synthetic crude and petroleum.
Oil reserves in sedimentary rocks are the source of hydrocarbons for the energy, transport and petrochemical industry.
Economically important hydrocarbons include fossil fuels such as coal, petroleum and natural gas, and its derivatives such as plastics, paraffin, waxes, solvents and oils. Hydrocarbons – along with NOx and sunlight – contribute to the formation of tropospheric ozone and greenhouse gases.
Bioremediation[edit]
Bacteria in the gabbroic layer of the ocean's crust can degrade hydrocarbons; but the extreme environment makes research difficult.[16] Other bacteria such as Lutibacterium anuloederans can also degrade hydrocarbons.[17] Mycoremediation or breaking down of hydrocarbon by mycellium and mushroom is possible.[18]
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