Abstract: Petrographic and Chemical Variation in Coal Feed to a Kentucky Power Plant

HOWER, JAMES C. and CORTLAND F. EBLE

Pulverized coal feed, consisting of blended coals, many from multiple mine sources, was sampled at two 500 MW units at a single Kentucky power plant. One unit burns a blend of high-sulfur Illinois Basin and Northern Appalachian coals and the other unit burns a blend of low-sulfur Central Appalachian coals. Each pulverized coal sample was further screened at 100, 200, 325, and 500 mesh in order to determine the fineness of the coal and the chemical and petrographic properties of the size fractions.

The high-sulfur feed is a high-vitrinite coal, 85% (mineral-matter included), with a V-type range of v4 to v9. The lower reflectance vitrinite particles represent the Illinois Basin components in the blend. The low-sulfur feed has a more restricted V-type range, v7 to v10, with a total vitrinite content of 67%. The low-sulfur feed, strictly high volatile A bituminous in this sampling, does contain medium and low volatile bituminous components at some times.

In the coals in both units, the coarser sizes in the pulverized feed are dominated by the harder trimacerite microlithotypes. The trimacerites become more enriched in vitrinite in the finer size ranges. Vitrite and inertite are the dominant microlithotypes in the 500 mesh size fraction.

AAPG Search and Discovery Article #90939©1997 AAPG Eastern Section and TSOP, Lexington, Kentucky