Hydrogen transferring liquefaction of some bituminous coals with hydrogenated fluoranthene under high temperature-short contact time conditions

Hydrogen transferring liquefaction using hydrogenated fluoranthene at high temperatures was very effective for three Japanese bituminous coals, with a total yield of oil and asphaltene > 85 wt%. The high temperature-short contact time conditions (480 °C for 10 min or 510 °C for 2.5 min) resulted in a total yield of > 90 wt% from the coal of lowest rank, with low consumption of hydrogenated fluoranthene. The oil yields were as high as 75 and 68 wt% at 480 °C and 510 °C, respectively. In contrast, the lower temperature of 450 °C appeared more effective in diminishing preasphaltene formation with the highest rank coal providing oil and asphaltene yields of 47 and 38 wt%, respectively. Longer times or higher temperature increased the oil yield but without reducing the preasphaltene. Higher temperature was found favourable for the formation of asphaltene of lower molecular weight. The reactivity of butiminous coals of different rank is discussed from the viewpoint of their structure.