Earth and Environmental Science

9.6. Organic Geology: 4. The uses of coal and oil

Syllabus reference (October 2002 version)
4. The uses of coal and oil	*Students learn to:* describe the refining of coal describe the refining of petroleum, including distillation and catalytic cracking describe and evaluate the uses of coal and oil as fuels and raw materials for industry	*Students:* gather and present information from secondary sources to construct flow charts and diagrams of the processes used in refining fossil fuels

Extract from Earth and Environmental Science Stage 6 Syllabus (Amended October 2002).© Board of Studies, NSW.

Prior learning: Science Stages 4–5 Syllabus: Outcomes 4.11 (content 4.11.1 c ), Outcome 5.11 (content 5.11.1 b).

gather and present information from secondary sources to construct flow charts and diagrams of the processes used in refining fossil fuels

Gather information from chemistry and geology books, journals and from digital technologies including the Internet.
Extract the appropriate information required from the sources and construct flow charts to best explain the processes used.
Present this information to the class. It could be done in an oral or written form with the charts and diagrams to assist the presentation.

describe the refining of coal

Refining Coal

When coal is burnt to produce energy, sulfur is released.
To avoid environmental problems the coal is cleaned.
All types of coal cleaning are called coal beneficiation.
The coal may be cleaned in three ways: physical, chemical or biological cleaning.
Physical cleaning separates dirt, rocks and pyritic sulfur (sulfur combined with iron) from the coal.
- The coal is crushed and ground into a powder, then washed in water
- Density is used to separate the unwanted materials from the coal.
- Up to 90% of the pyritic sulfur is removed.
Column flotation is used to remove the remaining pyritic sulfur from the coal.
- The coal is chemically treated to stick to rising air bubbles in water.
- The inorganic matter sinks to the bottom of the flotation tank.
Chemical cleaning is used to remove the organic sulfur, combined with the carbon in the coal.
- Molten-caustic leaching is one technique used in which the coal is chemically treated, removing the sulfur.
Biological cleaning involves using bacteria to literally eat the sulfur from the coal. This is a relatively new technique.

describe the refining of petroleum, including distillation and catalytic cracking

Refining petroleum

The earliest formed petroleum compounds are large molecules (long chain hydrocarbons). When subjected to higher temperatures, during formation they transform into simpler hydrocarbons (short chained). This process is termed cracking.
A petroleum refinery obtains crude oil of various types of hydrocarbons (short chain and long chain).
To separate the complex mixture of different molecular sized hydrocarbons, a distillation tower is used.
Distillation is the principal method for separating crude oil into useful products.
The distillation tower contains chambers in which hydrocarbons are condensed and separated from the lighter fractions. The heavier fractions are condensed at the bottom chambers while the lighter fractions are distilled and transferred to the top chambers where they are condensed.
Petroleum distillation produces a number of useful petroleum products used in industry.

describe and evaluate the uses of coal and oil as fuels and raw materials for industry

Coal’s main use as a fuel is in power stations to generate electricity. Water is heated using the burning coal and is changed to steam, which turns turbines that generate the electricity.
Coal is the main form of electricity generation in Australia as it is readily available and is cheap.
Coal products are used in perfumes, briquettes, disinfectants, dyes, herbicides, plastic, roofing, explosives and pharmaceuticals.
Petroleum products are used as a fuel in the form of petrol, aviation gasoline, kerosene, diesel fuel and heating oil. Other uses are lubricants, waxes, asphalt, synthetic fibres such as plastics, pharmaceuticals, dyes and solvents.
Discuss in a group the value of the different uses. When you are considering value, you need to think about value to whom: the society in general; you and your family; businesses; the government?