Efficiency of hydrogen transferring liquefaction of a subbituminous coal using hydrogenated fluoranthene for short contact time at high temperature and low pressure

An Australian subbituminous coal (Wandoan) was effectively liquefied at 490 and 510 °C under nitrogen pressure of 2.5 MPa for 1.0-7.5 min using 1, 2, 3, 3a-tetrahydrofluoranthene (4HFL) as a hydrogen-donating solvent. The yields of oil and asphalthene could be as high as 58 and 24 wt%, respectively. The content of 4HFL was very influential on the oil yield although under appropriate liquefaction conditions, a considerable amount remained after reaction. The kinetics of the reaction and analytical study of the products and the solvent suggest consecutive as well as instantaneous depolymerization in the process. The coking or recondensation reaction was very rapid after 4HFL was consumed, confirming the efficacy of the short contact time liquefaction.