2i. New Technologies: Fluidized Bed Boiler Technology

 Another technology used in North Dakota coal-fired plants is the fluidized bed boiler technology. This technology uses a coal-particle mix suspended by an upward flow of air within a bed of sand. As the speed of the mixture increases, the gas/solid mix exhibits fluid-like properties. When the mixture undergoes combustion, water in the tubes around the boiler evaporates into steam. Fluidized bed combustion system advantages include complete combustion of the fuel, increased heat efficiency, and easy-to-remove ash. 

Both Heskett and Spiritwood use fluidized bed boiler technology.