Method and system for obtaining a butylene product

The present invention concerns a process (100) for the production of a butylene product (9) in which a component mixture (2) containing butane, butylene and hydrogen is provided using a butane dehydrogenation (10) to which a reaction feed (1) containing butane and hydrogen is subjected, the component mixture (2) or part thereof being subjected as a first separation feed to a first membrane separation (40), by means of which a first permeate (3) enriched in hydrogen with respect to the first separation feed and a first retentate (4) depleted in hydrogen with respect to the first separation feed and containing hydrogen, butane and butylene are formed, the first retentate (4) or part thereof being subjected to a second membrane separation (50) as a second separation feed, in which a second permeate (6) containing at least the predominant part of the hydrogen of the second separation feed and a second retentate containing at least the predominant part of the butane and the butylene of the second separation feed are formed, wherein the first membrane separation (40) is carried out using a sweep gas (5) containing butane and the first permeate (3) is obtained as permeate (3) charged with butane of the sweep gas (5) and/or the second membrane separation (50) is carried out using the sweep gas (5) containing butane and the second permeate (6) is obtained as permeate (6) charged with butane of the sweep gas (5), and wherein the first permeate (3) charged with butane of the sweep gas (5) and/or the second permeate (3) charged with butane of the sweep gas or one or more parts thereof is used in the formation of the reaction feed (1). A corresponding plant is also the subject of this invention.