THE CHEMICAL NATURE OF MATERIAL RELEASED FROM COAL-DERIVED ASPHALTENES BY REPRECIPITATION AND CYCLOHEXANE EXTRACTION

The yields and chemical nature of n-pentane solubles released from three coal-extract asphaltenes by reprecipitation with n-pentane and cyclohexane extraction have been investigated. With increasing concentration of n-pentane solubles in the original coal liquid, the yield of oils obtained by reprecipitation increases, as also does the tendency for their structures to resemble those of the original n-pentane solubles. No alkanes below C//4//0 were released from the asphaltenes by extraction with cyclohexane and therefore the long alkyl chains must be bound to aromatic, carboxyl or heteroatomic groups.