Australian brown coal was liquefied, using tetrahydrofluoranthene (4HFL) as solvent under high temperature and short contact time conditions. This liquefaction method was very effective in producing oil and asphaltene, and the best yields (67 and 10%) were achieved in the reaction at 510 degree C for 2. 5 min. The liquefaction with a solvent of less 4HFL at 450 degree C was found also efficient in producing oil and asphalten with the least of gas production. Deashing pretreatment of the coal in methanol-1N-HCl aq. solution for 24h removed calcium, magnesium and iron ions from the coal and improved the yields of oil and asphaltene to 68 and 14%, respectively. The favorable effects of less 4HFL to increase asphaltene by depressing gas yield, gave an oil plus asphaltene yield as high as 90%. Preheating was found also effective in improving the yields to 75 and 9% when the preheating was strictly performed at 360 degree C. Such pretreatment decreased principally the gas yields. Effects of pretreatment in the liquefaction reaction were discussed in connecton with the structure of the brown coal, although the effects were rather limited because of very high efficiency of 4HFL.
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