Abstract: Process for obtaining a pure hydrocarbon from a starting material containing the hydrocarbon including performing an extractive distillation of the starting material containing the hydrocarbon in an extractive distillation column using a solvent comprising an N-substituted morpholine having substituents with no more than seven carbon atoms; feeding the sump product of the extractive distillation column into a distillation separator column at an entry point in a center portion of the distillation separator column; distilling off the hydrocarbon from the top of the distillation separator column but advantageously returning a minor portion of it as a reflux; drawing off solvent from the sump of the distillation separator column; feeding the solvent drawn off from the sump of the distillation separator column into an evaporator to form a vapor in the evaporator at the pressure, p.sub.2, the pressure p.sub.2 in the evaporator being lower than the pressure p.sub.

Abstract: A simultaneous recovery of pure benzene and pure toluene is performed by extractive distillation with N-formylmorpholine and/or other N-substituted morpholines whose substituents contain not more than seven C-atoms as a solvent. From the entry product by predistillation, a benzene fraction boiling in the region between 75.degree. and 85.degree. C. and a toluene fraction boiling in the region between 99.degree. and 111.degree. C. is separated. The benzene fraction is supplied in the lower part, and the toluene fraction is supplied in the upper part of the extractive distillation column separated by a chimney plate into two parts.