A comparison of coal-water slurry pipeline systems

Coal-water slurry pipeline systems are in various stages of development and exhibit many similarities, but they also have several unique characteristics. Existing and proposed systems range from conventional coarse- and fine-coal slurry pipeline media to the stabilized flow and coal-water mixture slurries that are under development. The roles planned for the coal being burned and the coal slurry pipeline, combined with the advantages and disadvantages of the alternative systems, tend to determine which system is most applicable for a particular use. Principal selection criteria include transport distance, water requirements, cost, and end use. Conventional coarse-coal slurries are best suited to very short-distance applications, where low water use is possible through closed-loop operation. Conventional fine-coal slurries generally require greater preparation and dewatering costs but can be transported great distances. These two systems offer excellent opportunities for rapid implementation because they have been tested on a full-scale basis. Use of the stabilized-flow system offers opportunities for domestic combustion and export because it is cheaper than coal-water mixtures. Coal-water mixtures provide the unique capability to displace oil use in oil-fired boilers. The coal-water pipeline systems for stabilized-flow and coal-water mixtures have not yet been tested on a large-scale basis.