Separation of microcrystalline wax, paraffin wax and oil fractions from intermediate waxes by solvent fractionation extraction and fractionation crystallization

Abstract

Separation of microcrystalline wax, paraffin wax and oil fractions from intermediate waxes, type 500SW and 600SW slack waxes, were performed by using solvent fractionation extraction and fractionation crystallization techniques. This investigation tried to study the effect of the temperature and solvent (MEK and toluene) on these slack-waxes fractionations. It was found that the MEK was more suitable for task than toluene. The MEK fractionation extractions were performed from temperatures of 20 to 60 ํC. Paraffin waxes, which contain large amount of straight chain hydrocarbons, were preferentially separated at extracting temperature of 60 ํC. Microcrystalline waxes, which contain large amount of branched-chain hydrocarbons, showed better separation at 30, 40 and 50 ํC. The fractionation crystallization using MEK was performed at 10, 0, -10 and -20 ํC. Both microcrystalline waxes, which were separated at 10 and 0 ํC, and fractionated oils, which were separated at -10 and -20 ํC, contain large amount of naphthenic hydrocarbons. It was apparent that the fractionated waxes and oils, from fractionation of 500SW and 600SW slack waxes, contained normal paraffin waxes, microcrystalline waxes which contain branched-chain hydrocarbons, microcrystalline waxes which contain naphthenic hydrocarbons and oils which contain naphthenic hydrocarbons.