Abstract:
A process for the oxidative dehydrogenation of n-butenes to butadiene is disclosed herein, in which the formation of butadiene peroxides from butadiene in the work-up of the product gas mixture from the oxidative dehydrogenation is effectively prevented.
Abstract:
The invention relates to a process for preparing butadiene from n-butenes, which comprises the following steps: A) provision of a feed gas stream a comprising n-butenes; B) introduction of the feed gas stream a comprising n-butenes and an oxygen-comprising gas into at least one dehydrogenation zone and oxidative dehydrogenation of n-butenes to butadiene, giving a product gas stream b comprising butadiene, unreacted n-butenes, water vapor, oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases; C) cooling and compression of the product gas stream b in at least one compression stage, giving at least one condensate stream c1 comprising water and a gas stream c2 comprising butadiene, n-butenes, water vapor, oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases; D) separation of incondensable and low-boiling gas constituents comprising oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases as gas stream d2 from the gas stream c2 by Da) absorption of the C4-hydrocarbons comprising butadiene and n-butenes in a high-boiling absorption medium, giving an absorption medium stream loaded with C4-hydrocarbons and the gas stream d2, Db) removal of oxygen from the absorption medium stream loaded with C4-hydrocarbons by stripping with an inert gas and Dc) desorption of the C4-hydrocarbons from the loaded absorption medium stream to give a C4 product gas stream d1 which consists essentially of C4-hydrocarbons and comprises less than 100 ppm of oxygen; E) separation of the C4 product stream d1 by extractive distillation with a solvent which is selective for butadiene into a stream e1 comprising butadiene and the selective solvent and a stream e2 comprising n-butenes; F) distillation of the stream e1 comprising butadiene and the selective solvent to give a stream f1 consisting essentially of the selective solvent and a butadiene-comprising stream f2.
Abstract:
The process for preparing butadiene from n-butane comprises the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone; C) compressing in at least one first compression stage and cooling the gas stream b; D) absorbing the butenes and the stream c2 comprising butadiene, n-butane, hydrogen and water vapor, with or without inert gases and with or without carbon oxides, with a selective solvent; E) extractively distilling the selective solvent; F) distilling the selective solvent; G) feeding stream f and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butenes.
Abstract:
The process for preparing butadiene from n-butane comprises the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone; C) compressing in at least one first compression stage and cooling the gas stream b; D) absorbing the butenes and the stream c2 comprising butadiene, n-butane, hydrogen and water vapor, with or without inert gases and with or without carbon oxides, with a selective solvent; E) extractively distilling the selective solvent; F) distilling the selective solvent; G) feeding stream f and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butenes.
Abstract:
In a process for removing oxygen from a C4-hydrocarbon stream comprising free oxygen by catalytic combustion, in which the hydrocarbon stream comprising free oxygen is reacted by catalytic combustion over a catalyst bed in the presence or absence of free hydrogen to give an oxygen-depleted hydrocarbon stream, the catalytic combustion is carried out continuously, the entry temperature in the catalyst bed is at least 300° C. and the maximum temperature in the catalyst bed is not more than 700° C.