Date of Award


Document Type


Degree Name

Master of Science (MS)


Chemical Engineering


North Dakota lignite, (,-lV x 1") in size and having 35 percent initial moisture content, was steam dried by the Fleissner process at elevated temperatures and pressures. The reduction in moisture content of lignite was investigated as a function of the residence time and the drying temperature. The residence time was varied from 10 to 30 minutes and the drying temperature from 220° to 270°C.

It was determined that decrease in moisture content was independent of drying times longer than 20 minutes and drying temperatures below 250°C. The reduction in moisture content increased at higher temperatures. It varied from 45 to 73 percent for varying conditions. The linear shrinkage of lignite was observed to be between 10 and 15 percent. Steam dried lignite did not significantly reabsorb moisture. Residual water and vent gas were analyzed.