Structures and Hydrogen Donating Abilities of Liquefaction Residues

Abstract

The liquefaction residues discharged from the NEDOL process, were extracted with carbon disulfide-N-methyl-2-pyrrolidinone mixed solvent at room temperature. The extraction yields were 86.1%, 91.1%, 90.1% for Illinois, Wyoming, Wandoan coal liquefaction-residues, respectively. The fractionation of the extract showed that the amount of acetone-soluble fraction was 53%-64%. From ultimate analysis and FTIR measurements, the extract fractions had a higher aromaticity and a lower content of oxygen (especially hydroxyl group) than those for the corresponding raw coals. Heat treatment of the liquefaction residue with a bituminous coal was carried out at 250°C to evaluate the hydrogen donating ability of the liquefaction residue to the bituminous coal. The content of soluble fraction increased by the heat treatment with the bituminous coal, compared to that calculated from the heat treatment of each component alone, indicating that the liquefaction residue donated hydrogens to the raw coal moiety even at temperature as low as 250°C.