Abstract: The invention relates to a process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising n-butenes, B) feeding the input gas stream a comprising n-butenes and a gas containing at least oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, giving a product gas stream b comprising butadiene, unconverted n-butenes, water vapor, oxygen, low-boiling hydrocarbons and high-boiling secondary components, with or without carbon oxides and with or without inert gases; Ca) cooling the product gas stream b by contacting with a cooling medium in at least one cooling zone, the cooling medium being at least partly recycled and having an aqueous phase and an organic phase, Cb) compressing the cooled product gas stream b which may have been depleted of high-boiling secondary components in at least one compression stage, giving at least one aqueous condensate stream c1 and one gas stream c2 comprising butadiene, n

Abstract: The invention relates to a process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising n-butenes, B) feeding the input gas stream a comprising n-butenes and a gas containing at least oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, giving a product gas stream b comprising butadiene, unconverted n-butenes, water vapor, oxygen, low-boiling hydrocarbons and high-boiling secondary components, with or without carbon oxides and with or without inert gases; Ca) cooling the product gas stream b by contacting with a cooling medium in at least one cooling zone, the cooling medium being at least partly recycled and having an aqueous phase and an organic phase of an organic solvent, wherein the organic solvent is selected from the group consisting of toluene, o-, m- and p-xylene, mesitylene, mono-, di- and triethylbenzene, mono-, di- and triisopropylbenzene and mixtures thereof, and the mass ratio of

Abstract: The invention relates to a process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising n-butenes, B) feeding the input gas stream a comprising n-butenes and a gas containing at least oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, giving a product gas stream b comprising butadiene, unconverted n-butenes, water vapor, oxygen, low-boiling hydrocarbons and high-boiling secondary components, with or without carbon oxides and with or without inert gases; Ca) cooling the product gas stream b by contacting with a cooling medium in at least one cooling zone, the cooling medium being at least partly recycled and having an aqueous phase and an organic phase, Cb) compressing the cooled product gas stream b which may have been depleted of high-boiling secondary components in at least one compression stage, giving at least one aqueous condensate stream c1 and one gas stream c2 comprising butadiene, n

Abstract: The invention relates to a process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising n-butenes, B) feeding the input gas stream a comprising n-butenes and a gas containing at least oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, giving a product gas stream b comprising butadiene, unconverted n-butenes, water vapor, oxygen, low-boiling hydrocarbons and high-boiling secondary components, with or without carbon oxides and with or without inert gases; Ca) cooling the product gas stream b by contacting with a cooling medium in at least one cooling zone, the cooling medium being at least partly recycled and having an aqueous phase and an organic phase of an organic solvent, wherein the organic solvent is selected from the group consisting of toluene, o-, m- and p-xylene, mesitylene, mono-, di- and triethylbenzene, mono-, di- and triisopropylbenzene and mixtures thereof, and the mass ratio of

Abstract: Valve arrangement for a system which is loaded with fluid, for connecting a first pressure region to a second pressure region by means of a first valve and a second valve connected in series. A third valve connects a region between the first valve and the second valves to a third pressure region. The first valve closes when a pressure which prevails on the side of the second pressure region is at least as high as a pressure which prevails on the side of the first pressure region. The first valve is coupled to the second valve so that the second valve closes when the first valve closes. The second valve is coupled to the third valve so that the third valve opens when the second valve closes.

Abstract: Valve arrangement for a system which is loaded with fluid, for connecting a first pressure region to a second pressure region by means of a first valve and a second valve connected in series. A third valve connects a region between the first valve and the second valves to a third pressure region. The first valve closes when a pressure which prevails on the side of the second pressure region is at least as high as a pressure which prevails on the side of the first pressure region. The first valve is coupled to the second valve so that the second valve closes when the first valve closes. The second valve is coupled to the third valve so that the third valve opens when the second valve closes.

Abstract: A wound heat exchanger is disclosed. The heat exchanger includes a plurality of tubes which are wound in several concentric tube layers about a central tube, and a container cover which defines an external chamber about the tube. A first anti-drumming wall is shaped as a cylinder cover or a cylinder cover segment and is arranged on the external side of a first layer of tubes.

Abstract: A wound heat exchanger is disclosed. The heat exchanger includes a plurality of tubes which are wound in several concentric tube layers about a central tube, and a container cover which defines an external chamber about the tube. A first anti-drumming wall is shaped as a cylinder cover or a cylinder cover segment and is arranged on the external side of a first layer of tubes.