Patent ID: 7435860
Filing Date: 2008-10-14
Classification: C07C

Abstract:
1. A process for preparing butadiene from n-butane, comprising the steps of A) providing a feed gas stream (a) comprising n-butane; B) feeding said feed gas stream (a) into at least one first dehydrogenation zone and nonoxidatively, catalytically dehydrogenating n-butane to obtain a gas stream (b) comprising n-butane, 1-butene, 2-butene, butadiene, and hydrogen, and optionally comprising carbon dioxide and/or steam; C) feeding said gas stream (b) and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to obtain a gas stream (c) comprising n-butane, butadiene, hydrogen, carbon dioxide, and steam; D) compressing in at least one first compression stage and cooling said gas stream (c) to obtain at least one condensate stream (d E) separating said gas stream (d F) compressing in at least one further compression stage and cooling said gas stream (e G) cooling said gas stream (f H) removing water from said at least one condensate stream (f