In developing coal slurry fuels to replace oil and gas in utility and industrial steam generation and in diesel and turbine engines, coal purity and theological specifications have been attained at the expense of the fuel's energy value. The result of this concession is the derating of boilers, reduction in effective storage capacity, and reduced ranges and added weight in transportation applications. Two methods for increasing the coal content in ultra fine coal slurry fuels have been identified and will be explored in Phase 1. When developed, these will increase the energy value of the fuel by as much as 20%. The first procedure involves adding surface-modifying chemicals to exploit the increased fluidity of aqueous suspensions of particles having the surface property of hydrophobicity. In the second method, the coal slurry fuel is subjected to intense, localized mechanical shearing that conditions morphology of the coal particles and improves slurry fluidity. The methods will be explored in detail to provide a thorough understanding of the controlling variables and allow systems to be optimized for their implementation in coal slurry fuel production.Anticipated Results/Potential Commercial Applications as described by the awardee:An understanding of the two methods for increasing the coal content of ultra fine coal slurry fuels will be developed and employed in selecting optimal conditions and arrangements for implementation in the production process. By these methods, as much as 10 wt% of the coal may be added to the slurry to enrich the fuel's energy value by as much as 20%. This technology offers a direct solution to the space and weight limitation problems facing those trying to use coal slurries as transportation fuels in diesel and turbine engines. The additional energy value will reduce the derating of boilers encountered when converting from oil to coal slurry fuels and will reduce the required fuel storage facilities by as much as 20%.
