Correlation and path coefficient analysis between thermal extraction yield and coal properties.

Thermal extraction yields were obtained for 13 coals in supercritical ethanol at 250°C. The direct and indirect relationships between extraction yield and coal properties were determined using correlation and path analyses. Both nitrogen content and hydrogen content have significant and positive correlations with thermal extraction yield. However, moisture content, sulfur content, and oxygen content exhibited negative correlations with extraction yield. Path analysis demonstrated that nitrogen and carbon contents had significant direct and indirect influences on extraction yield, respectively. Nitrogen content is the preferential factor for a high extraction yield, followed by carbon and hydrogen contents. [ABSTRACT FROM PUBLISHER]