Topic summary
Brown coal
Extracted from the Wikipedia article Lignite.
Characteristics
Lignite has a high content of volatile matter which makes it easier to convert into gas and liquid petroleum products than higher-ranking coals. Its high moisture content and susceptibility to spontaneous combustion can cause problems in transportation and storage. Processes which remove water from brown coal reduce the risk of spontaneous combustion to the same level as black coal, increase the calorific value of brown coal to a black coal equivalent fuel, and significantly reduce the emissions profile of 'densified' brown coal to a level similar to or better than most black coals. However, removing the moisture increases the cost of the final lignite fuel.