There’s different types of coal, with black and brown coal being two of the major types.
In this guide we discuss more about those different types of coal, their different properties, and how they might be used in slightly different ways.
Summary – Types Of Coal (& Uses)
Coal comes in various types, from the softer brown coal with higher moisture content and lower amounts of carbon and energy content, to various stages of harder black coal with less moisture and more carbon and energy content
We mainly use coal in society for energy generation for electricity, but also for key products and processes like steel production.
Read more about how/why coal is important to society in this guide
Different coal types have different properties, and have different emission rates of both carbon dioxide and air toxins
Over time, through coalification, lignite (brown coal), to sub-bituminous coal, to bituminous coal and finally to anthracite (black coal)
Charcoal and peat can sometimes be confused for coal, but they aren’t
Major Types Of Coal
Coal might be broadly categorised into black and brown coal.
But, the major types of coal are:
Hard and black. Contains a high percentage of fixed carbon and a low percentage of volatile matter.
Has a high heating (Btu) value and is the most common type of coal used in electricity generation in the United States
Black in color … and has a higher heating value than lignite
Lignite (Brown coal)
Brown coal, is the lowest grade coal with the least concentration of carbon
Coking coal or coke is also made by heating coal or oil with the absence of air.
Over time, coal progresses in rank from lignite, to sub-bituminous coal, to bituminous coal and finally to anthracite; a process known as coalification.
As the coal increases in rank, the carbon content – and hence the energy content – increases, whilst the moisture content decreases
According to environmentvictoria.org.au, coal is formed when plant material is subjected to high temperatures and pressures lasting millions of years.
Several stages are involved in the formation of coal.
Plant material, wood
Brown coal (lignite)
Black coal (sub-bituminous, bituminous and anthracite)
… Each successive stage has a lower water content and a higher energy content.
This means that when the same quantity of each material is burned, a greater amount of heat is released for each successive stage.
Other Materials Often Related To Coal
These materials might not be coal technically, but they are often related to coal:
Is man made, whereas coal is naturally formed
Not actually coal.
But, it is the first step in the process of a material becoming lignite/brown coal.
High pressure and heat turns peat into coal
How The Different Types Of Coal Are Used
Coal has a major use as an energy source for electricity (burning of coal creates heat, the heat boils water, and steam from the water moves large turbines to create energy).
But, how the different types of coal are used depends on the country and region they are used in.
The type of coal found in a particular region and how abundant and cheap it is might determine how it’s used.
For example, even though brown coal tends not to have as much energy per unit as black coal, it might be cheaper to use in some countries and regions and might be used in coal power plants there (as it can help supply cheap electricity).
It can depend on logistics and other factors.
Aside from using black or brown coal for energy and fuel, coal can be used for:
Making steel – coking coal is used in steel production
Used as an ingredient in making other chemicals and products
Black coal is also used in cement manufacture, alumina refining, paper manufacture and for other industrial purposes (ga.gov.au)
Read more about the uses of coal at https://www.worldcoal.org/coal/uses-coal
Emissions From The Different Types Of Coal
OurWorldInData.org has a good graph/chart showing how much carbon dioxide each type of coal fuel source emits per unit of electricity produced – view it at https://ourworldindata.org/fossil-fuels
In order of most to least emissions:
Sub Bituminous Coal
Something to note is that more brown coal (in quantity) might need to be burnt compared to black coal to get the same amount of energy, and this can contribute to higher carbon emission rates.
So, the inefficiency of brown coal might contribute to it’s higher carbon release rate per unit of electricity.
A Note About How Coal Types Can Differ Even Further
Apart from the general types of coal described above, coal can also differ based on where it is found in the world.
For example, certain types of Chinese coal might have slightly different properties than certain types of Australian coal.