hesc103

Introduction

  • Natural resources can be broadly classified into two kinds:

    • Inexhaustible Natural Resources: Unlimited and not likely to be exhausted (e.g., sunlight, air).

    • Exhaustible Natural Resources: Limited in quantity and can be exhausted by human activities (e.g., forests, wildlife, minerals, coal, petroleum, natural gas).

Group Activity (Activity 3.2)

  • Objective: Understand resource consumption through a practical exercise.

  • Materials: Containers filled with popcorn, peanuts, etc.

  • Procedure:

    • Students divided into groups to represent different consumer generations.

    • Each generation consumes resources from the containers.

    • Observe resource availability and consumption patterns to evaluate greed and generational resource use.

Exhaustible Natural Resources Overview

Coal

  • Physical Properties:

    • Hard, black substance (Fig. 3.1).

  • Uses:

    • Fuel for cooking, thermal power plants, and industries.

Formation of Coal

  • Formed approximately 300 million years ago from lush forests in wetland areas.

  • Buried under layers of soil due to natural events (e.g., flooding).

  • Under pressure and high temperatures, dead vegetation transformed into coal through a process known as carbonisation, classifying it as a fossil fuel.

Coal Products

  • Coal Gas:

    • Obtained during coal processing for coke production.

    • Historically used for street lighting; now primarily a heat source.

  • Coke:

    • Tough, porous black substance; pure carbon.

    • Used in steel manufacturing and metal extraction.

  • Coal Tar:

    • Thick, black liquid containing about 200 substances.

    • Raw material for various products (e.g., synthetic dyes, drugs, plastics).

    • Naphthalene balls, used to repel insects, are derived from coal tar (Fig. 3.3).

Petroleum

Definition and Origin

  • Mined Resource: Derived from organisms in the sea.

  • Formation Process:

    • Bodies settled at the sea bottom, covered by sand and clay.

    • Under pressure and absence of air, they transformed into petroleum and natural gas (Fig. 3.4).

  • Refining Process:

    • Separation of petroleum into various constituents (e.g., petrol, diesel) occurs during refining (Fig. 3.5).

Products and Uses of Petroleum

  • Key Constituents (See Table 3.1):

    • Petrol: Motor fuel, aviation fuel.

    • Diesel: Fuel for heavy vehicles.

    • Kerosene: Fuel for stoves; jet aircraft.

    • Lubricating oil: Used for machinery.

    • Paraffin wax: For ointments and candles.

    • Bitumen: Used in road surfacing.

Natural Gas

  • Characteristics: Easily transported through pipelines; often referred to as compressed natural gas (CNG).

  • Uses:

    • Power generation, cleaner fuel for vehicles, starting material for chemicals and fertilizers.

    • Major reserves found in Tripura, Rajasthan, Maharashtra, etc.

Conclusion: Sustainability of Resources

  • Exhaustibility: Fossil fuels, including coal and petroleum, are limited resources.

  • Their combustion contributes to air pollution and global warming.

  • Sustainable use encourages environmental preservation and resource availability over time.

  • Efforts like those from the Petroleum Conservation Research Association (PCRA) promote energy conservation practices.

Key Concepts

  • Fossil Fuels: Coal, petroleum, and natural gas formed from dead organic material.

  • Resource Conservation: Importance of judicious use of exhaustible resources for the environment.

Exercises

  1. List advantages of using CNG and LPG.

  2. Identify petroleum products used for road surfacing.

  3. Describe coal formation and the process involved.

  4. True/False statements about fossil fuels.

  5. Discuss conservation efforts for fossil fuels.