A process for recovering crude 1,3-butadiene from a C4 fraction by extractive distillation using a selective solvent in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column to form a first subregion (A), a second subregion (B) and a lower common column region (C) and which is preceded by an extractive scrubbing column (K), wherein the operation of the dividing wall column (TK) is set by regulation of the energy input into the dividing wall column (TK) via a bottom vaporizer (V) and setting of the number of the theoretical plates in the lower common column region (C) so that a bottom stream (17) consisting of purified solvent is obtained from the dividing wall column (TK), is proposed.