METHOD FOR SEPARATING A C₄ FRACTION BY MEANS OF EXTRACTIVE DISTILLATION USING A SELECTIVE SOLVENT

摘要

A method is provided for separating a C₄ fraction (2) by means of extractive distillation using a selective solvent (1) by way of counter-flow of the C₄ fraction (2) and of the selective solvent (1) in a liquid phase in a distillation unit (K I, K II), while separating a head flow (3) comprising the butanes and butenes from the C₄ fraction and a bottom flow (6) comprising the selective solvent and the remaining components of the C₄ fraction, with the exception of the butanes and butenes, the selective solvent being outgased from the fraction in an additional step, characterized in that energy is extracted from the distillation unit (K I, K II) between the extraction point for the head flow (3) and the extraction point for the bottom flow (6).