Preparation for upgrading western subbituminous coal

The objective of this project was to establish the physical and chemical characteristics of western coal and determine the best preparation technologies for upgrading this resource. Western coal was characterized as an abundant, easily mineable, clean, low-sulfur coal with low heating value, high moisture, susceptibility to spontaneous ignition, and considerable transit distances from major markets. Project support was provided by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The research was conducted by the Western Research Institute, (WRI) in Laramie, Wyoming. The project scope of work required the completion of four tasks: (1) project planning, (2) literature searches and verbal contacts with consumers and producers of western coal, (3) selection of the best technologies to upgrade western coal, and (4) identification of research needed to develop the best technologies for upgrading western coals. The results of this research suggest that thermal drying is the best technology for upgrading western coals. There is a significant need for further research in areas involving physical and chemical stabilization of the dried coal product. Excessive particle-size degradation and resulting dustiness, moisture reabsorption, and high susceptibility to spontaneous combustion are key areas requiring further research. Improved testing methods for the determination of equilibrium moisture and susceptibility to spontaneous ignition under various ambient conditions are recommended