Characterization on the ultraclean carbons extracted from direct coal liquefaction residue using petroleum ether.

Direct coal liquefaction residue is a coal waste with high ash and sulfur content, but also rich in valuable organic carbons. In this work, the ultraclean carbons were obtained by solvent extraction using petroleum ether at a mild temperature. The petroleum ether extractable fraction is ash-free with high carbon content, but low nitrogen and sulfur. The petroleum ether extractable fraction is reasonable to be cleaned for fuel use or converted into carbon products. Detailed characterizations on the chemical composition and structural features of petroleum ether extractable fraction were performed to supply fundamental information for additional treatment. [ABSTRACT FROM AUTHOR]