Abstract
Experiments have been conducted to obtain the optimum condition of steam drying process to produce upgraded coals with low moisture content. An Indonesian low rank coal, Berau coal, which has high moisture content and sulfur content of 20.02% in air dried basis (adb) and 3.09% in dry basis (db) respectively, was upgraded for 15 - 75 minutes in an autoclave at 200 °C, and at 175 - 275 °C for 60 minutes. Both of raw and upgraded coals have been analyzed to give moisture and sulfur content for the evaluation of the optimum condition of process. The result indicates that the moisture content is significantly decreased become 5.16% in adb at temperature of 275 °C for 60 minutes. On the contrary, the sulfur content was not significantly decreased.
