Coal-water slurry systems for oil-design power plants. Final report

This study is a preliminary exploration of the feasibility of producing a slurry of pulverized cleaned coal in water and burning it in boilers designed for fuel oil combustion. The objective of this proposed system is the substitution of coal for oil at some existing power plants. The goals of this study were to review and assess the status of technology for each element of the system, to consider costs in a preliminary way and to suggest areas where additional technical efforts might be advantageous. Cost comparisons based on current fuel prices are generally favorable for coal-water slurries produced from coal that has been mechanically cleaned to less than 3% ash. Further processing of coal with chemical reagents to reduce its sulfur and ash content (possibly achieving < 0.5% ash) is technically feasible; however, the economics of the available processes is prohibitive. There are three different laboratories, each using a different approach, that have produced small quantities of slurries containing 70% of pulverized (minus 200 mesh) coal in water. It is recommended that larger quantities of slurry be produced promptly to supply material for commercial scale burner development tests.