Lignite is a coal in the early stages of coalification, with properties intermediate to those of
bituminous coal and peat. The two geographical areas of the U. S. with extensive lignite deposits are
centered in the States of North Dakota and Texas. The lignite in both areas has a high moisture content
(20 to 40 weight percent) and a low heating value (5,000 to 7,500 British thermal units per pound
[Btu/lb], on a wet basis). Due to high moisture content and low Btu value, shipping the lignite would not
be feasible; consequently, lignite is burned near where it is mined. A small amount is used in industrial
and domestic situations, but lignite is mainly used for steam/electric production in power plants. Lignite
combustion has advanced from small stokers to large pulverized coal (PC) and cyclone-fired units
(greater than 500 megawatt)