METHOD AND DEVICE FOR SEPARATING A HYDROCARBON-CONTAINING FEEDSTOCK STREAM BY EXTRACTIVE DISTILLATION

The invention relates to a method for separating a hydrocarbon-containing feedstock stream (1) by means of extractive distillation, wherein the feedstock stream (1) is brought into contact (110) in counter-current with a water-soluble solvent (4) for aromatics, an aliphatic fraction is distillatively separated (120) from the obtained mixture (5) as an aliphatic product stream (2), the aromatics are stripped (130) from the remaining aromatics-enriched solvent (6), and the aromatics-depleted solvent (4) is returned (140) to a solvent circuit (7); wherein compounds having a lower boiling point than the solvent (4) collect as impurities in the solvent circuit (7), and at least one partial stream (8) of the solvent circuit (7) is purified (150) to remove the impurities; wherein the partial stream (8) undergoes a thermal separation process for the purification (150), in which thermal separation process the impurities are at least partially conducted away in a top product (11) and the remaining purified solvent (10) is returned to the solvent circuit (7). The invention also relates to a device for carrying out the method.