Coal Classification and Properties

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the approximate average calorific value of bituminous coal?

20000 kJ/kg

35000 kJ/kg

25000 kJ/kg

31350 kJ/kg (correct)

Which type of coal is described as having a very small amount of smoke when burned?

Anthracite

Semi-bituminous coal

Caking coal

Non-caking coal (correct)

What is the main characteristic of semi-anthracite coal compared to true anthracite?

Less luster and fixed carbon (correct)

Higher soot production

Higher fixed carbon content

Lower volatile matter content

What percentage of volatile matter does semi-bituminous coal typically contain?

15 to 20 percent Signup and view all the answers

How is fixed carbon content (FC) in coal typically determined?

By subtracting moisture, volatile matter, and ash percentages Signup and view all the answers

What various materials are transformed into ash when coal is burned?

Mineral compounds Signup and view all the answers

Which statement is true about anthracite coal?

It is very hard and ignites slowly Signup and view all the answers

What does a high fixed-carbon content in coal indicate about its combustion time?

It requires a long combustion time Signup and view all the answers

Which of the following best describes calorific value?

The energy released when coal is burned. Signup and view all the answers

What is the main characteristic of anthracites as a heating fuel?

They burn steadily for a long time with short flames. Signup and view all the answers

Which process refers to burning coal in air to release thermal energy?

Combustion Signup and view all the answers

What does proximate analysis help to determine in coal?

The moisture and volatile combustible matter. Signup and view all the answers

What is the primary combustible element in coal on a weight basis?

Carbon Signup and view all the answers

What is charcoals key characteristic compared to other solid fuels?

It burns rapidly with a clear flame. Signup and view all the answers

What are briquettes primarily made from?

Dust, culm, slack, and other small waste Signup and view all the answers

What is the typical temperature range for obtaining soft coke from coal?

600-650°C Signup and view all the answers

What is the primary purpose of conversion in coal utilization?

To transform coal into gaseous or liquid fuels. Signup and view all the answers

What does ultimate analysis provide in comparison to proximate analysis?

A precise chemical composition of coal. Signup and view all the answers

Which of the following components of coal is responsible for its combustible properties?

Hydrogen Signup and view all the answers

Which type of coke is characterized by burning with smoke?

Hard coke Signup and view all the answers

What characteristic does asphalt have when it comes to usage?

Used for making roads Signup and view all the answers

What is one advantage of liquid fuels compared to solid fuels?

They have a higher calorific value per unit mass. Signup and view all the answers

Which of the following liquid fuels is commonly used in transportation?

Diesel Signup and view all the answers

What type of oil is referred to as 'bunker fuel'?

Residual fuel oil and heavy fuel oil Signup and view all the answers

What is a major disadvantage of using fuel oil compared to solid fuel?

Fuel oil has a higher cost. Signup and view all the answers

What is the main composition of gasoline?

A mixture of paraffins, naphthenes, and olefins Signup and view all the answers

Which of the following elements is NOT a basic component of coal?

Helium Signup and view all the answers

Gasoline is primarily used in which type of engine?

Internal combustion engines Signup and view all the answers

What is a common risk associated with the use of liquid fuels?

Increased risk of tire hazards. Signup and view all the answers

Which of the following classes of fuel oil is NOT commonly mentioned?

Synthetic oil Signup and view all the answers

Which chemical constituents are primarily found in petroleum?

A mix of hydrocarbons, nitrogen, and sulfur Signup and view all the answers

What type of hydrocarbons does asphaltic base type crude petroleum mainly consist of?

Cycloparaffins or naphthenes Signup and view all the answers

What is the primary use of kerosene?

As jet fuel and heating fuel Signup and view all the answers

Which of the following terms is commonly used to refer to gasoline in different parts of the world?

Petrol Signup and view all the answers

Which of the following processes is NOT used to manufacture mineral oils?

Thermal cracking Signup and view all the answers

What is a primary characteristic of paraffin wax?

It is a white, odorless, tasteless solid Signup and view all the answers

What is the main component of Liquefied Petroleum Gas (LPG)?

Propane and butane Signup and view all the answers

Which type of crude petroleum contains semisolid waxes?

Mixed base type Signup and view all the answers

What distinguishes the different classifications of lubricating oils?

Their chemical structure: paraffinic, naphthenic, or aromatic Signup and view all the answers

What is the primary application of bitumen?

Paving roads and waterproofing roofs Signup and view all the answers

Study Notes

Coal Classification and Characteristics

Bituminous coal has an average calorific value of 31350 kJ/kg
Bituminous coal can be caking or non-caking
Non-caking coal is softer than anthracite and burns with minimal smoke
Semi-bituminous coal contains 15-20% volatile matter and tends to break into small pieces during storage or transportation
Semi-anthracite coal contains less fixed carbon and luster compared to anthracite and produces longer, more luminous flames when burned
Anthracite is a very hard coal with a shiny black luster. It ignites slowly unless the furnace temperature is high, burns with very short blue flames or without flames, and is a popular domestic heating fuel.

Coal Composition and Properties

Coal contains minerals that are transformed into ash when burned.
Fixed carbon is the solid combustible residue remaining after volatile matter is expelled from a coal particle during heating.
A high fixed carbon content indicates a longer combustion time for coal.

Coal Testing and Analysis

Proximate analysis determines the moisture, volatile matter, fixed carbon, and ash content of coal.
Ultimate analysis provides a precise chemical composition of coal in terms of carbon, hydrogen, oxygen, nitrogen, sulfur, and ash.

Coal Utilization

Combustion involves burning coal in air to release thermal energy.
Carbonization is the heating of coal to high temperatures in the absence of air.
Conversion processes transform coal into gaseous or liquid fuels, known as synthetic fuels.

Manufactured Solid Fuels

Charcoal is derived from the destructive distillation of wood and burns rapidly with a clear flame, producing no smoke.
Soft coke is obtained from the destructive distillation of coal between 600-650°C and contains 5-10% volatile matter.
Hard coke is obtained from the destructive distillation of coal between 1200-1400°C and burns with smoke.
Briquettes are compressed small pieces of coal, lignite, peat, or coke into a regular shape with or without a binder.

Liquid Fuels

Liquid fuels possess a higher calorific value per unit mass, burn without dust, ash, or clinkers, and are easily transported through pipes.
Liquid fuels are more expensive than solid fuels and require special storage tanks.

Petroleum

Petroleum is a dark greenish brown, viscous mineral oil mainly composed of hydrocarbons (paraffins, cycloparaffins, olefins, and aromatics).
Petroleum is classified into paraffinic base type, asphaltic base type, and mixed base type.

Main Products of Petroleum

Asphalt is used in road construction and is a colloid of asphaltenes and maltenes.
Diesel is fuel used in diesel engines and is denser than gasoline.
Fuel oil is a liquid petroleum product burned in furnaces to generate heat.
Gasoline is used as fuel in internal combustion engines and is a mixture of paraffins, naphthenes, and olefins.
Kerosene is used as jet fuel and heating fuel and is a thin, clear, combustible liquid.
Liquefied Petroleum Gas (LPG) is a mixture of gases primarily used for heating, aerosols, and refrigerants.
Lubricating oil consists of base oils and additives and is classified as paraffinic, naphthenic, or aromatic.
Paraffin wax is a white, odorless, tasteless waxy solid used as an electrical insulator and in drywall insulation.
Bitumen, also known as tar, is a thick, black, sticky material used in paving roads and waterproofing roofs and boats.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the various types of coal, including bituminous, semi-bituminous, semi-anthracite, and anthracite. Learn about their characteristics, calorific values, and compositions. This quiz offers insights into coal's properties, helping you understand their applications in heating and energy.