Hydrocarbon Sources and Properties
Hydrocarbon like aliphatic, aromatic, or polynuclear aromatic hydrocarbons are types of organic compound processing hydrogen and carbon in the entire molecular formula with one or more single, double or triple bonds in two adjacent carbon atoms. When two or more carbon atoms processing by the single common bond are called saturated hydrocarbons but if the compound containing at least one pair of adjacent carbon atoms liked by multiple bonds are called unsaturated hydrocarbons in chemical science or organic chemistry. The natural crude oil or mineral oils are the main sources of aliphatic, aromatic, and cyclic hydrocarbons like methane, ethane, propane, cycloalkene, etc.
Natural gas is another source of hydrocarbons that define large quantities of gaseous substance with undissociated liquid petroleum fuel uses as the daily used energy sources. When the natural gas does not contain hydrocarbons above ethane are called lean or dry gas and contains the higher member of hydrocarbons are called rich or wet gases.
Chemical Properties of Hydrocarbons
The solubility of Hydrocarbons shows that hydrocarbon molecule is almost insoluble in water solvent but rapidly soluble in ethanol and ether solution. When we concern alkanes the attractive forces are only weak Van der Waals forces. The dipole moment of hydrocarbon like all alkanes whether straight or branched-chain will be zero. Zero polarity of these hydrocarbon associated due to balancing the C-H bonds by the remaining alkyl functional group. The position of the electromagnetic infrared spectrum region of the CH group depends on the carbon atom. Therefore, the stretching frequency region of hydrocarbons is following order, primary carbon > secondary carbon > tertiary carbon.
Hydrocarbon from Liquid Petroleum
Crude petroleum oil of our earth’s environment define mainly the gases with naturally occurring hydrocarbon family in the forms of liquified or the solid dissolved in liquid solvents. The density and composition of crude petroleum oil vary with the locality of occurrence but all saturated with organic compounds mainly liquid hydrocarbon. Therefore, crude petroleum oil contains a list of isoparaffinic alkanes, cycloalkenes or naphthenes, and aromatic or polynuclear aromatic hydrocarbons. In addition to the hydrocarbon study, there are also contain known derivatives of hydrocarbons containing oxygen, nitrogen, sulfur, and crystalline metallic atom.
Naturally, crude petroleum is classified into two types as paraffinic or asphaltic which contains hydrocarbon compounds like alkane and naphthalene. According to this classification crude oil from Pennsylvania, Iran and Rumania contain paraffinic but from Baku, Venezuela is an asphaltic type of hydrocarbon. Also from Texas, Mexico, Oklahoma is an intermediate type of hydrocarbon.
Hydrocarbon from Natural Gas
The terms natural gas meaning the total quantity of gaseous hydrocarbons present in used liquid petroleum. Therefore, the main component of natural gas varies according to the source. Hence natural gas consists chiefly of the first six alkanes or hydrocarbons and the percentage of occurrence decreases with increasing molecular weight.
The hydrocarbon separated from natural gas by fractional distillation formula under pressure uses in different energy generation purposes in our daily life. Oxidation of natural gas under controlled conditions produces a mixture of organic aldehyde, acid, acetone, and alcohol which we use in the different chemical industries. Hydrocarbon like methane, ethane, propane, butane, pentane, and hexane obtained when natural gas combustion about the temperature 200-300°C with 1-200 atm pressure in presence of a catalyst.
Structure and Classification of Hydrocarbons
The valence shell electronic configuration of carbon in hydrocarbons molecule, 2s2 2px1 2py1 2pz. When the electron from 2s-orbital promotes to vacant 2pz-orbital and hybridization to form four equivalent sp3 hybrid orbitals. Therefore, these four hybridized orbitals of carbon atom mixing with the hydrogen atom to form saturated organic compounds. But for sp2 and sp-hybridization, the carbon atom not saturated by valency four. Therefore, the term saturated hydrocarbon meaning carbon saturated by valency four but in unsaturated carbon is not saturated by valency four. According to the structural dimensions and definition in chemistry, hydrocarbon meaning open chain, cyclic or closed chain, saturated, and unsaturated carbon-hydrogen organic compounds present in our environment.
Saturated and Unsaturated Types Hydrocarbons
The list of organic compounds that contain two or more carbon atoms linking by only a single chemical bond name by the term saturated compounds or hydrocarbons. Hence methane, ethane, methyl alcohol, ethyl alcohol, etc are examples of the common saturated compounds. But methane, ethane, propane, and cycloalkanes are examples of common saturated hydrocarbon because these compounds form by carbon and hydrogen bonding.
The compound contains at least one pair of multiple bonds in adjacent carbon atoms called unsaturated hydrocarbon. If the double or triple bond contains on the adjacent carbon atoms known as alkenes or olefin and alkynes (acetylene) respectively. But in acetaldehyde, the multiple bonds between adjacent carbon and oxygen atom not considered for unsaturation.
Hydrocarbon Alkane Alkene and Alkyne
- Alkanes or paraffin is the saturated type of hydrocarbons that contain the single bonds on adjacent carbon atom obtained from natural sources like crude petroleum oil with general molecular formula Cn H2n+2.
- Alkene or olefin is also the hydrocarbon contains one double bond or olefinic chemical bond on two adjacent carbon atom with the general molecular formula CnH2n.
- Alkyne is an organic hydrocarbon contains one triple bond or acetylenic bond on two adjacent carbon atoms with the general molecular formula CnHn.
Alicyclic and Cyclic Types Hydrocarbon
- The carbon and hydrogen atoms in the closed ring structure define as a carbocyclic or homocyclic hydrocarbon. Therefore, the alicyclic compounds show aliphatic characteristics name as alicyclic hydrocarbons.
- The saturated types of cyclic hydrocarbon take the name of the corresponding open-chain hydrocarbons, proceeds by the suffixes cyclo. Therefore, these compounds collectively called cycloparaffins or cycloalkanes. If the alicyclic hydrocarbon is unsaturated, then this hydrocarbon termed as cycloalkenes.
Aliphatic and Aromatic Hydrocarbons
With the development of learning chemistry, the organic hydrocarbon is divided mainly into two types which are pronounce as aliphatic and aromatic.
- The aliphatic naming of hydrocarbons given from fatty acids but today these compounds known as open-chains compounds. Therefore, several examples of saturated or unsaturated hydrocarbons coming from natural sources names as the aliphatic hydrocarbon.
- The aromatic types name of hydrocarbon obtained from the Greek prefixes aroma meaning fragrant smell. The details characteristics show that the aromatic hydrocarbon compound contains the ring with the aromatic property and most of the hydrocarbons molecule related to the benzene ring or derivative of benzene. The cyclic benzenoid compound has aromatic properties but the properties of these compounds totally different from alicyclic hydrocarbons molecule.
Cracking of Liquid Hydrocarbon
The thermal bond dissociation of organic molecules like hydrocarbon known as pyrolysis. Thermal creaking produces a list of hydrocarbons or classes alkanes from the higher member of the alkane family. Hence alkane decomposed to lower alkanes by specific heat like 500°C to 600°C. The product obtained from a given alkane depends on, structure, applied pressure, and used catalyst. Therefore, the thermal decomposition of a list of hydrocarbons like decane given lower alkane octane and ethene.
C10H22 → C8H18 + CH2=CH2
If we using suitable catalysts, alkanes containing six or more carbon atoms are cyclized. Therefore, in the presence of the chemical element platinum as a catalyst, hydrocarbon decane cyclized to form benzene.
C6H14 → C6H12 + H2 → C6H6 + 3H2
Organic fuels like petroleum oil creaking uses for the extraction of the most common list of liquid hydrocarbon like aliphatic, aromatic, polyaromatic hydrocarbons. For example, the most important list of hydrocarbon like methane, ethane, ethane, propane, butane, and isobutene obtains from organic fuels that contain up to four carbon atom in its molecular formula.