Power Point Presentation OnFormation, Occurrence, Extraction And Refining Of

Coal And Petroleum.

Submitted By : Satya Patra, VIII B, Roll No. 22

Introduction

Coal

Coal is a non-renewable, combustible, hard, black solid substance, consisting chiefly of carbonised plant matter, found mainly in underground seams and used as fuel.

Petroleum

Petroleum is a non-renewable, combustible fuel which mainly consists of hydrocarbons, and is generally found in liquid state under the sea beds.

Fossil fuels

The fuels which were formed by the decomposition of the remains of animal and plants dead bodies are known as fossil fuels. E.g. Coal and Petroleum.

FormationHow coal was formed?

Millions of years ago, the Earth had dense forests in low-lying wetland areas. Due to natural processes such as flooding, these forests were buried underneath soil. As more and more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. As the process continued the plant matter was protected from biodegradation and oxidation, usually by mud or acidic water. This trapped the carbon that was eventually covered and deeply buried by sediments. Under high pressure and high temperature, dead vegetation and in the absence of air the plant matter was slowly converted to coal. As coal contains mainly carbon, the conversion of dead vegetation into coal is called carbonization.

How petroleum was formed?

Petroleum was formed by the decomposition of tiny plants and animals buried deep under the sea, millions of years ago. Millions of years ago, the plants and animals which lived under the sea died. Their bodies sank deeper and deeper in to the bottom of the sea. Soon they were covered by sediments like mud and sand. Due to high temperature and pressure, action of bacteria, and in the absence of air, the dead remains of the plants and animals were gradually converted into petroleum. That’s why petroleum is found between to layers of impervious rocks (non-porous rocks).

Millions of years ago the earth had swamps that were buried by natural phenomena such as landslides, flooding, earthquakes, etc.

These dead remains got covered by sediments like mud and sand. Under great pressure, heat, action of bacteria, absence of air, the dead remains slowly got converted into coal and petroleum. The plant remains got converted into coal whereas the remains of marine vegetation got converted into natural gas and petroleum

OccurrenceOccurrence of coal

Coal is found in beds or seams interstratified with shales, clays, sandstones, or (rarely) limestones. It is usually under laid by an underclay (a layer of clay containing roots of plants). The coal is removed by strip (surface) mining or underground mining methods.

Occurrence of petroleum

Petroleum occurs deep under the surface of the earth between two layers of impervious rocks (non-porous rocks). Petroleum being lighter than water, floats over water. Petroleum deposits are usually found mixed with water, salt, silt, and earth particles such as sand, clay, etc.. Petroleum does not occur in all the places of earth. It is found only in certain places of earth. Natural gas occurs just above the petroleum oil trapped under the rocks.

Extraction

Extraction of coal

Coal is extracted through deep shaft mining in which very deep holes are made to reach the ore lying at a great beneath the crust. The most economical method of coal extraction from coal seams depends on the depth and quality of the seams, and the geology and environmental factors. Coal mining processes are differentiated by whether they operate on the surface or underground. Many coals extracted from both surface and underground mines require washing in a coal preparation plant.

Extraction of petroleum

Geologists use different machines to locate petroleum reservoirs. After petroleum deposits are found petroleum is extracted by drilling holes (called oil wells) in the earth’s crust, where the presence of oil has been predicted by the survey.

RefiningRefining of coal [categorization]

Depending on the carbon content coal can be categorized into:

Anthracite (Highest carbon content, upto 90% carbon content)

Bituminous

Lignite

Peat (lowest carbon content )

Products of coal

Coal, when heated in absence of air, produces a number of useful products. These are:

Coal gas

Coal tar

Coke

Coal gas, coal tar and cokeCoal Gas

Coal gas is a gaseous fuel which is obtained by the strong heating of coal in the absence of air during the processing of coal to get coke.

Coal gas contains a variety of calorific gases including hydrogen, carbon monoxide, methane and volatile hydrocarbons together with small quantities of non-calorific gases such as carbon dioxide and nitrogen.

Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system.

Coal Tar

Coal tar is a brown or black liquid of extremely high viscosity. Coal tar is among the by-products when coal is carbonized to make coke or gasified to make coal gas. Coal tars are complex and variable mixtures of phenols, polycyclic aromatic hydrocarbons.

It is a thick, black liquid having an unpleasant smell which is obtained by heating coal in absence of air.

Coal tar is not a single compound. Coal tar is a mixture of about 200 carbon compounds (0r organic compounds).

The useful carbon components present in coal tar include benzene, toluene, naphthalene, anthracene, phenol, aniline.

These components are separated through fractional distillation.

The products of coal tar are used to make synthetic fibres, drugs (medicines), plastics, etc.

Coke

Coke is a tough and porous black solid substance.

Coke is a fuel with few impurities and a high carbon content, usually made from coal. It is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur coal.

Cokes made from coal are grey, hard, and porous. While coke can be formed naturally, the commonly used form is man-made. The form known as petroleum coke, or pet coke, is derived from oil refinery cooker units or other cracking processes.

Coke is a better fuel than coal because it produces more heat on burning of coal. Moreover, coke produces very little smoke on burning.

Refining of petroleum oil (crude oil)

The crude petroleum oil is a mixture of solid, liquid and gaseous hydrocarbons. It is unusable in this form. So, petroleum oil is refined.

The refining of petroleum oil is carried out in an oil refinery.

The separation of petroleum into different fractions is done by a process called ‘fractional distillation’.

The various useful fractions obtained by the refining of petroleum are: Petroleum gas, Petrol, Kerosene , Diesel, Lubricating oil, Paraffin wax and Bitumen.

* Spelling mistakes: Refinery gas, kerosene.

The Various Fractions Of Petroleum And Their Uses

i. Petroleum gas : Petroleum gas is used as a fuel in homes and industry, sometimes in the form of Liquified Petroleum Gas (LPG).

ii. Petrol: Petrol is used as a fuel in light vehicles such as motorcycles, cars, etc.

iii. Kerosene: Kerosene is used as a fuel in wick stoves and pressure stoves to cook food, is also used for lighting purposes.

iv. Diesel: Diesel is used as fuel in heavy motor vehicles such as buses, tractors, trucks, etc.

v. Lubricating oil: Lubricating oil is used for lubrication in machines and engines (like car engines).

vi. Paraffin Wax: Paraffin wax is used for making candles, Vaseline, ointments, etc.

vii. Bitumen: Bitumen is used for road surfacing. It is also used for water-proofing the roofs of buildings.