Coal is an abundant fossil fuel resource with several end uses.
• Power generation
• Steel making
• Cement production
• Industrial uses
• Liquefaction and gasification
What a type of coal is used for depends on:
• Coal quality
• End use process
• Economics of use
• Availability of alternatives to coal
Coals are often classified as good quality and poor quality primarily based on energy, moisture or coking properties.
Consider that if the coal quality suits the end use then the coal is a good quality coal.
We will focus on power generation and clean coal technologies in this section. The vast majority of Indonesian coal is used in the power generation industry.
Environmental aspects of coal combustion are increasingly important. We will also look at these issues and uses of coal combustion products.
Coal Quality related to End Use
Coal Rank
The coal rank is a general guide to end use suitability.
There are three broad categories of utilisation.
• Metallurgical coals
Coals that have what are known as coking properties. When heated in a coke oven produce a strong porous solid residue (coke).
The coke is used in the steel making process.
Approximately 25% of world coal production are coking coals.
• Steaming coals
Coals that are combusted to raise steam for power generation.
Combustion can also provide direct heating such as in cement manufacture.
Approximately 70 % of world coal production are steaming coals.
• Conversion and special coals
Coals that are used as feed in the production of gaseous and/or liquid products derived from coal.
Coals used for special purpose e.g. active carbon electrodes.
These coals account for a small percentage of world coal production.