Abstract: The invention relates to a process for producing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, comprising: (a) mixing an amine comprising feed stream, a phosgene comprising feed stream and optionally an inert solvent; (b) reacting the amine with phosgene in a first reaction section to obtain an intermediate reaction mixture comprising isocyanate, carbamoyl chlorides, amine hydrochlorides and unreacted phosgene; (c) cleaving the carbamoyl chlorides and remove phosgene from the intermediate reaction mixture in a second reaction section to obtain an isocyanate comprising crude product, (d) optionally working-up the crude product; wherein reacting (b) is carried out such that the intermediate reaction mixture comprises 1.7 to 5 mol-% solid amine hydrochlorides based on the molar amount of amine fed into the process.

Abstract: A unit for producing and/or processing phosgene, preferably for producing and processing phosgene, said unit being configured for at least one production mode and at least one maintenance mode and comprising a structure which defines a confined space in a production mode, wherein (i) the confined space contains at least one apparatus for producing phosgene, or for processing phosgene, or for producing and processing phosgene; (ii) the structure comprises at least one openable and lockable transfer means for temporary removal, in a maintenance mode, of at least part of at least one apparatus according to (i) from the structure through at least one of said transfer means in opened state.

Abstract: A unit for producing and processing phosgene, said unit being configured for at least one maintenance mode and at least one production mode and comprising a structure which defines a confined space in a production mode, said confined space being sub-divided into at least two sub-spaces, wherein (i) at least one sub-space contains at least one apparatus for producing phosgene; (ii) at least one sub-space, other than the at least one sub-space according to (i), contains at least one apparatus for processing phosgene; (iii) the structure comprises at least one openable and lockable access means for temporary access of at least one of the apparatuses according to (i) or (ii) from outside the structure in a maintenance mode.

Abstract: The invention relates to a method for producing butadiene from n-butenes having the steps: A) providing an n-butene-comprising feed gas stream a; B) feeding the n-butene-comprising feed gas stream a and an oxygen-comprising gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, wherein a product gas stream b comprising butadiene, unreacted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling minor components, optionally carbon oxides and optionally inert gases is obtained; Ca) cooling the product gas stream b by contacting it with a refrigerant and condensing at least a part of the high-boiling minor components; Cb) compressing the remaining product gas stream b in at least one compression step, wherein at least one aqueous condensate stream c1 and a gas stream c2 comprising butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases is obtained; Da) separating off non-condensable and lo

Abstract: The invention relates to a process for producing butadiene from n-butenes which comprises the steps of: A) providing a vaporous n-butenes-comprising input gas stream a1 by evaporating a liquid n-butenes-comprising stream a0; B) introducing the vaporous n-butenes-comprising input gas stream a1 and an at least oxygenous gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene to obtain a product gas stream b comprising butadiene, unconverted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling secondary components, possibly carbon oxides and possibly inert gases, Ca) chilling the product gas stream b by contacting with a cooling medium comprising an organic solvent in at least one chilling zone, the cooling medium being at least partially recycled into the chilling zone, Cb) compressing the chilled product gas stream b which is possibly depleted of high-boiling secondary components in at least one compression stage to obtain at least one aqueous c

Abstract: The invention relates to a process for preparing 1,3-butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising butanes, 1-butene, 2-butene and isobutene, with or without 1,3-butadiene, from a fluid catalytic cracking plant; B) removing isobutene from the input gas stream a, giving a stream b comprising butanes, 1-butene and 2-butene, with or without 1,3-butadiene; C) feeding the stream b comprising butanes, 1-butene and 2-butene and optionally an, oxygenous gas and optionally water vapor into at least one dehydrogenating zone and dehydrogenating 1-butene and 2-butene to 1,3-butadiene, giving a product gas stream c comprising 1,3-butadiene, butanes, 2-butene and water vapor, with or without oxygen, with low-boiling hydrocarbons, with high-boiling secondary components, with or without carbon oxides and with or without inert gases; D) cooling and compressing the product gas stream c, giving at least one aqueous condensate stream d1 and a gas stream d2 comprising 1,3-buta

Abstract: The invention relates to a method for producing butadiene from n-butenes having the steps: A) providing a feed gas stream a comprising n-butenes; B) feeding the feed gas stream a comprising the n-butenes and an oxygen-comprising gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, wherein a product gas stream b comprising butadiene, unreacted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling minor components, possibly carbon oxides and possibly inert gases is obtained; Ca) cooling the product gas stream b by contacting it with a refrigerant and condensing at least a part of the high-boiling minor components; Cb) compressing the remaining product gas stream b in at least one compression stage, wherein at least one aqueous condensate stream c1 and a gas stream c2 comprising butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases are obtained; Da) separating off non-condensable and low-b

Abstract: A process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream comprising n-butenes; B) feeding the input gas stream 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; Ca) cooling the product gas stream by contacting with a circulating cooling medium in at least one cooling zone; Cb) compressing the cooled product gas stream in at least one compression stage, giving at least one aqueous condensate stream c1 and one gas stream c2; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons as gas stream d2 from the gas stream c2 by absorbing the C4 hydrocarbons in an absorbent, giving an absorbent stream laden with C4 hydrocarbons and the gas stream d2, and then desorbing the C4 hydrocarbons from the laden absorbent stream, giving a C4 product gas stream d1; E) separating the C4

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 method for producing butadiene from n-butenes having the steps: A) providing an n-butene-comprising feed gas stream a; B) feeding the n-butene-comprising feed gas stream a and an oxygen-comprising gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, wherein a product gas stream b comprising butadiene, unreacted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling minor components, optionally carbon oxides and optionally inert gases is obtained; Ca) cooling the product gas stream b by contacting it with a refrigerant and condensing at least a part of the high-boiling minor components; Cb) compressing the remaining product gas stream b in at least one compression step, wherein at least one aqueous condensate stream c1 and a gas stream c2 comprising butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases is obtained; Da) separating off non-condensable and lo

Abstract: The invention relates to a method for producing butadiene from n-butenes having the steps: A) providing a feed gas stream a comprising n-butenes; B) feeding the feed gas stream a comprising the n-butenes and an oxygen-comprising gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, wherein a product gas stream b comprising butadiene, unreacted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling minor components, possibly carbon oxides and possibly inert gases is obtained; Ca) cooling the product gas stream b by contacting it with a refrigerant and condensing at least a part of the high-boiling minor components; Cb) compressing the remaining product gas stream b in at least one compression stage, wherein at least one aqueous condensate stream c1 and a gas stream c2 comprising butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases are obtained; Da) separating off non-condensable and low-b

Abstract: 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 a dehydrogenation reactor and oxidative dehydrogenation of n-butenes to butadiene; C) cooling and compression of the product gas stream b in at least one cooling stage comprising a quenching column and in a compression stage comprising a compressor, with the product gas stream b being brought into contact with at least one circulated coolant; D) separation of incondensable and low-boiling gas constituents as gas stream d2 from the gas stream c2 by absorption of the C4-hydrocarbons in at least one circulated absorption medium; E) separation of the C4 product stream d1 by extractive distillation using 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 essenti

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 1,3-butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising butanes, 1-butene, 2-butene and isobutene, with or without 1,3-butadiene, from a fluid catalytic cracking plant; B) removing isobutene from the input gas stream a, giving a stream b comprising butanes, 1-butene and 2-butene, with or without 1,3-butadiene; C) feeding the stream b comprising butanes, 1-butene and 2-butene and optionally an, oxygenous gas and optionally water vapor into at least one dehydrogenating zone and dehydrogenating 1-butene and 2-butene to 1,3-butadiene, giving a product gas stream c comprising 1,3-butadiene, butanes, 2-butene and water vapor, with or without oxygen, with low-boiling hydrocarbons, with high-boiling secondary components, with or without carbon oxides and with or without inert gases; D) cooling and compressing the product gas stream c, giving at least one aqueous condensate stream d1 and a gas stream d2 comprising 1,3-buta

Abstract: A process for preparing butadiene from n-butenes, comprising the steps of: absorbing C4 hydrocarbons comprising butadiene and n-butenes, obtained from oxidative dehydrogenation of n-butenes, in an aromatic hydrocarbon solvent as an absorbent and removing uncondensable and low-boiling gas constituents comprising oxygen, low-boiling hydrocarbons, any carbon oxides, aromatic hydrocarbon solvent and any inert gases as gas stream d2, giving an absorbent stream laden with C4 hydrocarbons and the gas stream d2, and then desorbing the C4 hydrocarbons from the laden absorbent stream, giving a C4 product gas stream d1; and at least partly recycling the gas stream d2 as cycle gas stream a2 into the oxidative dehydrogenation zone, wherein the content of aromatic hydrocarbon solvent in the cycle gas stream a2 is limited to less than 1% by volume.

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 producing butadiene from n-butenes which comprises the steps of: A) providing a vaporous n-butenes-comprising input gas stream a1 by evaporating a liquid n-butenes-comprising stream a0; B) introducing the vaporous n-butenes-comprising input gas stream a1 and an at least oxygenous gas into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene to obtain a product gas stream b comprising butadiene, unconverted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling secondary components, possibly carbon oxides and possibly inert gases, Ca) chilling the product gas stream b by contacting with a cooling medium comprising an organic solvent in at least one chilling zone, the cooling medium being at least partially recycled into the chilling zone, Cb) compressing the chilled product gas stream b which is possibly depleted of high-boiling secondary components in at least one compression stage to obtain at least one aqueous c

Abstract: The invention relates to a process for producing butadiene from n-butenes, comprising the steps of: A) providing an n-butenes-comprising input gas stream a1, B) feeding the n-butenes-comprising input gas stream al, an oxygenous gas and an oxygenous cycle gas stream a2 into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene to obtain a product gas stream b comprising butadiene, unconverted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling secondary components, possibly carbon oxides and possibly inert gases, Ca) cooling down the product gas stream b and optionally at least partially removing high-boiling secondary components and steam to obtain a product gas stream b?, Cb) compressing and cooling the product gas stream b? in at least one compression and cooling stage to obtain at least one aqueous condensate stream c1 and one gas stream c2 comprising butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibl

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: A process for preparing butadiene from n-butenes, comprising the steps of: A) providing an input gas stream comprising n-butenes; B) feeding the input gas stream 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; Ca) cooling the product gas stream by contacting with a circulating cooling medium in at least one cooling zone; Cb) compressing the cooled product gas stream in at least one compression stage, giving at least one aqueous condensate stream c1 and one gas stream c2; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons as gas stream d2 from the gas stream c2 by absorbing the C4 hydrocarbons in an absorbent, giving an absorbent stream laden with C4 hydrocarbons and the gas stream d2, and then desorbing the C4 hydrocarbons from the laden absorbent stream, giving a C4 product gas stream d1; E) separating the C4