Tag: coal

Petroleum is a mixture of a very large number of different hydrocarbons; the most commonly found molecules are alkanes(kinds of paraffin), cycloalkanes(naphthenes), aromatic hydrocarbons, or more complicated chemicals like asphaltenes. Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like colour and viscosity.

In its strictest sense, petroleum includes only crude oil, but in common usage it includes all liquid, gaseous and solid hydrocarbons.Under surface pressure and temperature conditions, lighter hydrocarbons methane,ethane,propane and butane occur as gases, while pentane and heavier hydrocarbons are in the form of liquids or solids.

In its strictest sense, petroleum includes only crude oil, but in common usage, it includes all liquid, gaseous and solid hydrocarbons.Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier hydrocarbons are in the form of liquids or solids.

 $2,2,4-$trimethylpentane (isooctane), widely used in gasoline, has a chemical formula of $C _8H _8$ and it reacts with oxygen exothermically as shown below:

$2C _8H _{18}(l) + 25O _2(g) \longrightarrow 16CO _2(g) + 18H _2O(g)$

Crude oil is the raw material which is obtained from the earth's crust by drilling. It is brownish black in colour. It is then refined to obtain useful products such as petrol, diesel, kerosene, lubricating oil, etc. 

It tells us about the quality of gasoline whether there is some contamination present or the gasoline obtained is of low quality. The colour also shows us the indication whether it has gone through some chemical change. It shows gum forming tendency and thoroughness of the refining process.

Aviation turbine fuel means a refined middle distillate suitable for fuel in an aviation gas turbine internal combustion engine. Its boiling point is closest to that of kerosene.

The crude oil which is obtained from the earth's crust is in the raw form. It is refined in a refining tower. In this tower, the crude oil is heated at a temperature of 400 C. 

The process of formation of petroleum causes the organic matter to change, first into a waxy material known as kerogen, which is found in various oil shales around the world, and then with more heat into liquid and gaseous hydrocarbons via a process known as catagenesis.

Gasoline is a volatile mixture of liquid hydrocarbons generally containing small amounts of additives suitable for use as a fuel in a spark ignition internal combustion engine. The presence of sulphur in gasoline is undesirable due to its foul odour and also it forms gums.