Fuel Science & Technology International, Vol.14, No.3, 417-426, 1996
Chemical analysis of high ash Brazilian coal tar .2. Acid/basic/neutral separation of resins
Resins, obtained by chromatographic separation on silica-gel as described in a previous work (Lancas and Caramao, 1992), were fractionated by acid/basic/neutral separation in modified silica gel (acidic and basic) and characterized by infrared and elemental analysis. Resins were the major components found in the preparative liquid chromatographic fractionation of coal tar, and, for this reason, we tried to fractionated them into simpler fractions with the purpose of identifying their constituents. Six distinct cuts of coal tar (A to F) are subject to fractionation into acid/basic/neutral fractions, with large amounts of neutral compounds being found. The percent of acids found varied from 21.0 to 36.5, and the percent of bases varied from 3.2 to 8.0. The characterization of the individual fractions, confirm the success of the fractionation of the resins.