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Title: Formulation of slurries for slurry-fed coal gasifiers: Final report

Technical Report ·
OSTI ID:6393063

A 100 MW integrated gasification/combined cycle generating plant was recently put into operation at the Cool Water generating station of Southern California Edison Co. Coal is fed into the gasifier as a coal-water slurry. This report describes an experimental study on the slurryability of candidate gasifier coals and slurry formulation options for use in systems of this type. The ten candidate coals studied ranged in equilibrium moisture from 1 to 13%. Coal characterization included standard analyses, relative hydrophilic/hydrophobic nature, surface area, density, surfactant adsorption, and leachable ions. A ranking was made of the relative slurryability of the coals under two cases, with and without an added surfactant. Slurry formulation studies included the effects of size distribution, acid leaching, additional physical cleaning (both gravity separation and froth flotation), selected anionic and nonionic surfactants, pH, and oxidation to simulate weathering. Slurry viscosity can be lowered by using optimized size distributions which are broader than those achieved in typical grinders. Acid leaching was found to be a very effective method of reducing slurry conductivity, which could promote dispersion of the particles. The effect on viscosity for the specific coals studied, however, was not significant. Similarly, additional physical cleaning was found to have no significant effect on coal equilibrium moisture or loadings on a weight basis. Significant loading increases could be achieved using low concentrations of surfactants alone. This is particularly true for the higher rank coals, which have lower additive demand, and have a greater viscosity reduction at the optimum additive concentration. 17 refs., 27 figs., 25 tabs.

Research Organization:
Brookhaven National Lab., Upton, NY (USA); Electric Power Research Inst., Palo Alto, CA (USA)
DOE Contract Number:
AC02-76CH00016
OSTI ID:
6393063
Report Number(s):
EPRI-AP-5203; ON: DE87010950
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English