COAL & PETROLEUM
4
CHAPTER
Examples : Some solid fuels are :
CONTENTS (a) Coal (b) Coke
(c) Wood (d) Charcoal
Fuels (e) Animal-dung cakes
(f) Bagasse, Agricultural wastes
Classification of Fuels
Liquid fuels : Volatile liquids which
produce combustible vapour are called
Coal liquid fuels. Kerosene is the most
commonly used liquid fuel.
Destructive Distillation of Coal Examples : Some common liquid fuels are :
(a) Petrol (b) Diesel
Petroleum (c) Kerosene (d) Alcohol
Petrol, diesel and kerosene are mixtures of
Refining hydrocarbons.
Gaseous fuels : Combustible gases or
mixtures of combustible gases are called
FUELS gaseous fuels.
A combustible substance which on burning Examples : Some commonly used gaseous
produces a large amount of heat and light is fuels are :
called a fuel. (a) Natural gas
Coal, LPG , Petrol , Kerosene , wood etc. (b) Liquefield petroleum gas (LPG)
(c) Biogas (or Gobar gas)
CLASSIFICATION OF FUELS (d) Coal gas
Fuels are classified on the basis of physical (e) Water gas
sttes in which they occur. So fuels are classified (f) Producer gas
as solid, liquid and gaseous fuels. (g) Hydrogen gas
Classification of Fuels (h) Compressed Natural (CNG)
Petroleum gas is obtained as a by-product
during the fractional distillation of petroleum.
Solid fuels Liquid fuels Gaseous fuels Characteristics of an ideal fuel
Solid fuels : Combustible substances which An ideal fuel should have the following
are solid at room temperature are called characteristics :
solid fuels. Solid fuels contain mainly It should be fairly cheap and easily
carbon both as free and combined carbon. available.
In rural areas, Firewood, Agricultural It should burn at moderate rate.
wastes, Animal-dung cakes are the major It should not produce any poisonous and
source of energy. irritating fumes during burning.
It should leave no residue (ash) after burning.
, It should produce large amount of heat per Composition :
unit mass i.e., it should have high calorific Coal is a very impure form of carbon. It
value. mainly consists of atoms of carbon, hydrogen
It should be safe and convenient from the and oxygen. A small amount of sulphur is also
storage and tranportation point of views. present in it.
Its ignition temperature should be above Mining
room temperature. So that it is safe to use Coal is mined using two methods–opencast
such a fuel. mining and underground mining. Opencast
Uses of Fuels mining is used when the deposits of coal are
Cooking and Heating : The most common near the surface of the earth. Underground
use of fuels is for cooking and heating. The mining is used when coal deposits lie deep
commonly used domestic fuels are wood, inside the earth’s crust.
dry cattle dung, coal, charcoal, kerosene (in Formation
rural areas) and coal, kerosene, LPG (in Coal is formed from vegatable matter burried
urban areas). under the earth. About 300 million years ago,
For Transportation : Fuels such as petrol, the earth was covered with dense forests,
diesel and CNG are used for running cars, marshlands and rivers. The forests grew and
scooters, buses, trucks and trains. These died and fell into the waters of the surrounding
automobiles are used for transportation swamps. These plants were covered with tons
from one place to another. The fuel used in of earth over a period of millions of years. Due
aeroplanes is called aviation fuel. to the huge pressure and temperature inside the
For Generating Electricity : Fuels such as earth, this vegetable matter got converted into
coal and natural gas are used for generating coal. For this reason, coal is known as fossil
electricity on a commercial scale, in fuel. It is also a non-renewable source of
Thermal power stations. Petrol, diesel and energy.
kerosene are also used for generating Types of Coal
electricity in smaller generators commonly Coal comes in four main varieties. The
used at homes and shops, etc. percentage of carbon in air-dried samples are
In Industry : Fuels such as coal, natural as follows.
gas, diesel and furnace oil are used in the Peat : This is a material in the first stage of
industry for generating steam in boilers. coal formation. It contains only 27% carbon
Steam is required in industry for heating and is considered to be the lowest grade of
purposes and also for generating electricity
coal.
for their own use in factory. Industry in the
rural areas also uses biomass such as Lignite : This variety of coal contains 28-
bagasse—the cellulose material left after 30% carbon. It has poor heating power. It is
extracting juice from the sugarcane for brown in colour but lustrous when dry.
running boilers. Bituminous : It is a soft coal containing
For Launching Space Vehicles : Space 78-86% carbon. It gives a large proportion
vehicles are launched with the help of of gas when heated and burns with a
rockets. Rockets use special fuels called yellow, luminous flame.
propellants. A propellant is a combination Anthracite : It is a hard coal and contains
of a fuel and an oxidizer.
94-98% carbon. It is lustrous. It burns
COAL without smoke and gives much heat and
little ash.
Introduction : Bituminous coal is by far the most useful as
Coal is a mineral of dark brown or black colour a fuel, but anthracite is considered to be the
formed from the remains of plants buried in the
most superior in quality.
earth’s crust millions of years ago.
4
CHAPTER
Examples : Some solid fuels are :
CONTENTS (a) Coal (b) Coke
(c) Wood (d) Charcoal
Fuels (e) Animal-dung cakes
(f) Bagasse, Agricultural wastes
Classification of Fuels
Liquid fuels : Volatile liquids which
produce combustible vapour are called
Coal liquid fuels. Kerosene is the most
commonly used liquid fuel.
Destructive Distillation of Coal Examples : Some common liquid fuels are :
(a) Petrol (b) Diesel
Petroleum (c) Kerosene (d) Alcohol
Petrol, diesel and kerosene are mixtures of
Refining hydrocarbons.
Gaseous fuels : Combustible gases or
mixtures of combustible gases are called
FUELS gaseous fuels.
A combustible substance which on burning Examples : Some commonly used gaseous
produces a large amount of heat and light is fuels are :
called a fuel. (a) Natural gas
Coal, LPG , Petrol , Kerosene , wood etc. (b) Liquefield petroleum gas (LPG)
(c) Biogas (or Gobar gas)
CLASSIFICATION OF FUELS (d) Coal gas
Fuels are classified on the basis of physical (e) Water gas
sttes in which they occur. So fuels are classified (f) Producer gas
as solid, liquid and gaseous fuels. (g) Hydrogen gas
Classification of Fuels (h) Compressed Natural (CNG)
Petroleum gas is obtained as a by-product
during the fractional distillation of petroleum.
Solid fuels Liquid fuels Gaseous fuels Characteristics of an ideal fuel
Solid fuels : Combustible substances which An ideal fuel should have the following
are solid at room temperature are called characteristics :
solid fuels. Solid fuels contain mainly It should be fairly cheap and easily
carbon both as free and combined carbon. available.
In rural areas, Firewood, Agricultural It should burn at moderate rate.
wastes, Animal-dung cakes are the major It should not produce any poisonous and
source of energy. irritating fumes during burning.
It should leave no residue (ash) after burning.
, It should produce large amount of heat per Composition :
unit mass i.e., it should have high calorific Coal is a very impure form of carbon. It
value. mainly consists of atoms of carbon, hydrogen
It should be safe and convenient from the and oxygen. A small amount of sulphur is also
storage and tranportation point of views. present in it.
Its ignition temperature should be above Mining
room temperature. So that it is safe to use Coal is mined using two methods–opencast
such a fuel. mining and underground mining. Opencast
Uses of Fuels mining is used when the deposits of coal are
Cooking and Heating : The most common near the surface of the earth. Underground
use of fuels is for cooking and heating. The mining is used when coal deposits lie deep
commonly used domestic fuels are wood, inside the earth’s crust.
dry cattle dung, coal, charcoal, kerosene (in Formation
rural areas) and coal, kerosene, LPG (in Coal is formed from vegatable matter burried
urban areas). under the earth. About 300 million years ago,
For Transportation : Fuels such as petrol, the earth was covered with dense forests,
diesel and CNG are used for running cars, marshlands and rivers. The forests grew and
scooters, buses, trucks and trains. These died and fell into the waters of the surrounding
automobiles are used for transportation swamps. These plants were covered with tons
from one place to another. The fuel used in of earth over a period of millions of years. Due
aeroplanes is called aviation fuel. to the huge pressure and temperature inside the
For Generating Electricity : Fuels such as earth, this vegetable matter got converted into
coal and natural gas are used for generating coal. For this reason, coal is known as fossil
electricity on a commercial scale, in fuel. It is also a non-renewable source of
Thermal power stations. Petrol, diesel and energy.
kerosene are also used for generating Types of Coal
electricity in smaller generators commonly Coal comes in four main varieties. The
used at homes and shops, etc. percentage of carbon in air-dried samples are
In Industry : Fuels such as coal, natural as follows.
gas, diesel and furnace oil are used in the Peat : This is a material in the first stage of
industry for generating steam in boilers. coal formation. It contains only 27% carbon
Steam is required in industry for heating and is considered to be the lowest grade of
purposes and also for generating electricity
coal.
for their own use in factory. Industry in the
rural areas also uses biomass such as Lignite : This variety of coal contains 28-
bagasse—the cellulose material left after 30% carbon. It has poor heating power. It is
extracting juice from the sugarcane for brown in colour but lustrous when dry.
running boilers. Bituminous : It is a soft coal containing
For Launching Space Vehicles : Space 78-86% carbon. It gives a large proportion
vehicles are launched with the help of of gas when heated and burns with a
rockets. Rockets use special fuels called yellow, luminous flame.
propellants. A propellant is a combination Anthracite : It is a hard coal and contains
of a fuel and an oxidizer.
94-98% carbon. It is lustrous. It burns
COAL without smoke and gives much heat and
little ash.
Introduction : Bituminous coal is by far the most useful as
Coal is a mineral of dark brown or black colour a fuel, but anthracite is considered to be the
formed from the remains of plants buried in the
most superior in quality.
earth’s crust millions of years ago.
