Patent ID: 8092655

Claim:
A dividing wall column having a middle region which is divided into a feed section and an offtake section by a dividing wall and having the following segments a) to h): a) an upper column region, b) an enrichment section of the feed section which enrichment section has a cross-sectional area A b , c) a stripping section of the feed section which stripping section has a cross-sectional area A c , d) an upper part of the offtake section which upper part has a cross-sectional area A d , e) a lower part of the offtake section which lower part has a cross-sectional area A e , f) an intermediate region of the feed section, g) an intermediate region of the offtake section and h) a lower column region, wherein the dividing wall is located vertically between the segments b) and d) and between the segments c) and e), the segments b), d), c) and e) have separation-active internals, the cross-sectional area A b of the segment b) is at least 10% smaller than the cross-sectional area A d of segment d), and the cross-sectional area A b , of the segment c) is at least 10% greater than the cross-sectional area A e of segment e).