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 extractive distillation, wherein: the feedstock stream (1) is brought into contact (110) with a water-soluble solvent (4) for aromatics in a counterstream; an aliphatic-compounds fraction is distillatively separated (120) from the obtained mixture (5) as an aliphatic-compounds product stream (2); the aromatics are stripped (130) from the remaining aromatics-enriched solvent (6); and the aromatics-depleted solvent (4) is fed back (140) in a solvent circuit (7); wherein: aliphatic compounds and/or compounds which have aliphatic functional groups 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: for the purification (150), a liquid-liquid extraction is carried out between the partial stream (8) and an extraction agent (9) for aliphatic compounds and the raffinate (10) of the liquid-liquid extraction is fed back into the solvent circuit (7). The invention also relates to a device for carrying out the method.