A process for debottlenecking a system for the separation of a conjugated diolefin the system including a first extraction section having an extractive distillation column and a stripping column and a second extraction section. The process includes the steps of withdrawing a first portion of an extract from the extractive distillation column, the extract having at least the first portion and a second portion, and transferring the first portion of the extract to a flash/separation vessel; separating the first portion of the extract into a vapor phase and a liquid phase by flashing in a flash/separation vessel; and combining the liquid phase of the separated first portion of the extract with the second portion of the extract to produce an extract feed for further processing. A system and process for the separation of a conjugated diolefin from a C4- or C5-hydrocarbon mixture containing the conjugated diolefin and higher acetylenes are also provided.