Lecture Notes on Coal

Introduction

• Speaker: Dr. Muskaan, Magnet Brains
• Focus: Free education from kindergarten to class 12, available in English and Hindi mediums.
• Programs offered: Various state boards, CBSE, spoken English, Vedic Maths, crash courses, e-books, and notes.

Session Topic: Coal for Class 8

• Overview of what coal is, its formation, uses, and importance.

What is Coal?

• Definition: Hard black substance found thousands of feet below the earth.
• Hardness: Comparable to rock but can break under certain conditions.
• Composition: Mainly made of carbon, derived from dead plants and animals.

Fossil Fuels Recap

• Fossil fuels are formed from the decomposition of dead plants and animals.
• Examples: Coal, petroleum, and natural gas.
• Formation Process: Natural processes involving burial, accumulation, and decomposition.

Formation of Coal

• Historical Context: 300 million years ago, dense forests and wetlands existed.
• Process of Coal Formation:
  • Dead plants submerged in water due to storms and floods.
  • Became buried under layers of rocks, sand, and minerals.
  • High pressure and temperature led to incomplete decomposition (partial decomposition).
  • Resulted in formation of plant remains and eventually coal through carbonization.

Main Constituents of Coal

• Carbon as the primary component.
• Other elements: Hydrogen, nitrogen, oxygen, sulfur.

Types of Coal

• Major Types:
  • Anthracite
  • Bituminous
  • Lignite

Uses of Coal

• Historical Uses:
  • Cooking food.
  • Fuel for railway engines (produces steam).
• Modern Uses:
  • Electricity generation in thermal power plants.
    • Process involves heating coal to produce steam, which drives turbines to generate mechanical energy and electricity.
  • Fuel in various industries.

Three Forms of Coal

1. Coke: Solid form, tough and porous, used in iron and metal production.
2. Coal Tar: Liquid form, thick and unpleasant smell, used to make roads, dyes, drugs, and perfumes.
3. Coal Gas: Gas form obtained during processing of coal, used as fuel in industries.

Carbonization Process

• The conversion of plant remains into coal over millions of years due to specific conditions (high temperature, high pressure, lack of oxygen).
• Energy is conserved in different forms.

Importance of Coal

• Non-renewable resource, takes thousands of years to form.
• Must be used carefully to avoid depletion.
• Contrast with renewable resources (e.g., solar energy, water).

Conclusion

• Emphasis on understanding coal's formation and its uses.
• Encouragement to explore more educational content through Magnet Brains.
• Reminder of the availability of e-books and customized learning resources on the Magnet Brains website.