SCIENCE BLOG – COAL AND PETROLEUM
Here about some exhaustible natural resource like natural gas, coal and petroleum will be discussed, which are also called non-renewable sources of energy .This is because when all the natural gas coal and petroleum present under the earth will get used up, no more supply of these will be available in the near future.
Natural resource on Coal and petroleum
The various resources which are obtained from nature are called natural resources e.g. water, soil etc. on the other hand paint, synthetic fibers, plastics and explosives are man-made materials. Natural resources are broadly classified into two categories: `
INEXHAUSTIBLE NATURAL RESOURCES:
The various resources which are present in an unlimited quantity in nature and are not likely to be exhausted (used up) by human activities are called inexhaustible natural resources e.g. sunlight, air. There are never ending supply of inexhaustible resources in nature. They can be used again and again.
EXHAUSTIBLE NATURAL RESOURCES:
The natural resources which are present in a limited quantity in nature and can be exhausted (used up) by human activities are called exhaustible resources, e.g. natural gas, minerals, forests, wild life , coal and petroleum etc.
COAL: Coal is a hard, black combustible fuel. It is a fossil fuel. In India , coal is found mainly in bihar, West Bengal, Odissa and Madhya Pradesh (in deep coal mines under the surface of the earth)
PROCESS OF COAL FORMATION ON COAL AND PETROLEUM
About 300 million years ago, the earth had dense forests in low-lying wetland areas. Due to natural processes like flooding, earthquakes , volcanoes etc. These forests buried under the surface of the earth. As more soil deposited over them, there were compression. The temperature increases also as they are in more depth . Under high pressure, high temperature and also in the absence of air, the wood of dead plants got slowly converted into coal. Coal contains mainly carbon. The slow process of conversion of dead plants buried deep under the earth into coal terms as carbonisation. Since, there was coal formation from the remains of plants, (coal is also called a fossil fuel).
COAL IS A SOURCE OF ENERGY
Coal contains carbon. When heated in air, coal burns and produces mainly carbon di oxide gas. The reaction can be written as : C + O2 => CO2 + HEAT
USE OF COAL : ( fossil fuel )
- Coal is one of the fuels which we use to cook food
- It produces electricity in various industries
- Coal helps in manufacture of coke, coal tar and coal gas.
- It is the source of many organic compounds such as benzene, phenol, toluene, naphthalene etc.
PRODUCTS OBTAINED FROM COAL:
When we heat coal strongly in the absence of air in closed retorts, we obtain various useful products. The strong heat heating of coal in the absence of air we term as the destructive distillation of coal. These are coke, coal tar and coal gas.
It is a tough, porous and black solid substance. Coke is almost the pure form of carbon. It contains 98% carbon. When we heat coal in the absence of air, then elimination of gas and coal tar occur and we get coke as black residue.( coal and petroleum)
USES OF COKE:
- As a reducing agent in the metallurgy.
- In the manufacturing of steel
- As a fuel
COAL TAR (fossil fuel )
It is a thick, black liquid with having sticky scent. it is a mixture of about 200 substances. It contains useful carbon compounds present in coal tar include benzene, toluene, naphthalene, phenol, aniline, and anthracene.
USE OF COAL TAR on coal and petroleum
- We use it in making synthetic dyes
- Helps in making drugs
- We can make explosive
- Coal tar helps in making perfume
- We make plastics
- Various paints we can make.
It is a gaseous fuel. We obtain it during the processing of coal to get coke. It is mainly a mixture of methane and hydrogen with some carbon monoxide.
USE OF COAL GAS
- We use it as a fuel in many commercial and industrial places.
- Coal gas helps in lighting purposes
Petroleum is dark in colour, thick in consistent with sticky smell . It is present deep below the earth’s crust trapping in rocks in certain areas. The name petroleum means rock salt ( petra = rock ; oleum = oil). It is also called crude oil or mineral oil.
PROCESS OF FORMATION OF PETROLEUM :
The remains of plants and animals went under the sea forming petroleum by the decomposition, millions of years ago. ( coal and petroleum) Long before, the plants and animals which lived in the sea, died and their bodies settled at the bottom of the sea, and silt, mud, sand, clay wrapped those residual bodies. Due to high temperature, high pressure, and absence of air, these residual bodies convert into petroleum and natural gas. We can drill the oil wells hole to extract petroleum in the earth’s crust. In the drilling process, natural gas comes first with a great pressure and for a time, the crude petroleum oil comes out by itself due to gas pressure. Now we can drill out some of the oil wells under the sea for the extraction of petroleum.
LIQUIFIED PETROLEUM GAS (LPG) on COAL AND PETROLEUM
The petroleum gas which has been liquefied under pressure is known as LPG or liquefied petroleum gas. It is the most important fuel which we use in homes. It mainly consists of butane. LPG is a good fuel for the following reasons:
- Easily combustible
- It has a high calorific value (50,000 kJ/kg)
- LPG burns with a smokeless flame, so it does not cause any air pollution
PROBLEMS RELATED TO COAL AND PETROLEUM
SHORT TYPE QUESTION
Qs1: Mention various fractions of petroleum in coal and petroleum.
Ans1: The various fractions of petroleum are
- Petroleum gas in liquid form (LPG)
- Lubricating oil
- Paraffin wax
Qs2: Write the difference between coke and coal .
Ans2: Difference between coke and coal are
It is almost pure form of carbon
It mainly contains carbon.
Coke is an amorphous form of carbon
Coal is a non-crystalline form of carbon
If we heat coal in absence of air then we can get coke.
We get it by the process of decay of trees and plants over millions of years ago.
Qs3: What is the reason of being CNG as a good fuel other than petrol and diesel in vehicles?
Ans3: CNG is a good alternative to petrol and diesel in vehicles because it is a clean fuel and does not cause air pollution. It is filled in cylinders.
Qs4: What are the disadvantages of using fossil fuels?
Ans4: Disadvantages of using fossil fuel are:
- It causes air pollution.
- Global warming occurs as they produce greenhouse gases i.e. carbon dioxide gas on burning.
- The by-products of burning fuels causes acid rain which pollute water resources.
EXPLAIN THE FOLLOWING ON COAL AND PETROLEUM
Qs5: According to the scientists, fossil fuel will be exhausted shortly. Why?
Ans5: We can get fossil fuel only for very few tears as they may exhaust very soon. In nature we use up these in very fast rate than the consumption of other resources .They will get exhausted very soon. If the recent loading of these fossil fuels are exhausted , we cannot get any new sources of these in near future because dead organisms turn into fossil fuel in more than million years