Experimental Study on Super-Heated Steam Drying of Lignite

This paper applies super-heated steam drying technology to improve the quality of lignite. A unique experimental system was built up. In order to obtain the optimum operation conditions, the drying kinetics was measured. The temperature range of super-heated steam was from 120 to 200°C. The results showed that the drying process of super-heated steam drying of lignite can be well depicted by two stages, as a constant drying rate stage followed by a falling drying rate stage. The comparison of drying process to the hot air drying showed the superior advantages of super-heated steam drying on safety, drying capacity and energy conservation. Analysis shows the huge application potential of lignite in power plants by means of the super-heated steam drying.