Hydrocarbons

HYDROCARBONS
SOURCES OF HYDROCARBONS
*. Petroleum is the main source of aliphatic hydrocarbon.
*. Coal is the source of aromatic hydrocarbons PETROLEUM
*.
Viscous liquid found inside earth madeof dead remains of plants and animalsis called petroleum.
*.
Refing of petroleum is the process of separating it into different fractions.
Fractions
Composition
Boiling range
Uses
Uncondensed gases
C 1 - C 4
273 - 303 K
(a) Cymogene
(b) Rhigolenene
Manufacture of ice
Local anaethetic
Crude Naphtha
C 5 - C 10
303 - 423 K
(a) Petroleum ether
C 5 - C 6
303 - 343 K Solvent for oils , fats rubber and dry cleaning.
(b) Gasoline or Petrol
C 6 - C 8
343 - 363 K Fuel and dry cleaning
(c) Ligroin or Light Petroleum
C 6 - C 8
363 - 393 K Solvent for dry cleaning
Kerosene Oil
C 11 - C 18
393 - 573 K Fuel , for illumination , making oil gas
Diesel Oil or Heavy Oil
C 18 - C 45
Above 573 K Fuel in heavy automobiles
Residue
C 30 - C 45
Above 673 K
(a) Praffin wax
For candles and boot polishes
(b) Lubricating oils
For lubrications
(c) Vaseline
In oinments and toilet goods
(d) Pitch
In paints , varnishes and as fuel
(e) Petroleum coke
As fuel
*. NATURAL GAS about 90% methane and rest ethane , propane and butanes.
*. LPG is propane + butane
*. CNG is compressed natural gas.
OCTANE NUMBER
Octane number is used to determine the quality of gasoline. It is the percentage of isooctane in mixture of iso-octane and n-heptane which produces same knocking effect as the fuel under examination.
*. Higher the octane number , better the fuel.
*. Straight chain hydrocarbons have low octane number.
*. Octane number increases with increase in number of branches.
*. Unsaturated hydrocarbons and cycloalkanes have higher octane number than corresponding n-alknes.
*. Octane number of aromatic compounds is high.
*. Octane number of fuel is increased byadding TEL (tetra ethyl lead ).
*. Octane number of ordinary gasoline =74
*. Octane number of premiem gasoline =84 and above