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-butenes, water vapor, oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases, as gas stream d2 from the gas stream c2 by absorbing the C.sub.4 hydrocarbons comprising butadiene and n-butenes in an absorbent, giving an absorbent stream laden with C.sub.4 hydrocarbons and the gas stream d2, and then desorbing the C.sub.4 hydrocarbons from the laden absorbent stream, giving a C.sub.4 product gas stream d1, E) separating the C.sub.4 product stream d1 by extractive distillation with a butadiene-selective solvent into a stream e1 comprising butadiene and the selective solvent and a stream e2 comprising n-butenes; F) distilling the stream e1 comprising butadiene and the selective solvent into a stream f1 consisting essentially of the selective solvent and a stream f2 comprising butadiene, wherein stage Cb) comprises at least two compression stages Cba) and at least two cooling stages Cbb) configured in the form of quench columns, the cooling in the cooling stages being effected by direct contacting with a biphasic cooling medium having an aqueous phase and an organic phase.

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-butenes, water vapor, oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases, as gas stream d2 from the gas stream c2 by absorbing the C.sub.4 hydrocarbons comprising butadiene and n-butenes in an absorbent, giving an absorbent stream laden with C.sub.4 hydrocarbons and the gas stream d2, and then desorbing the C.sub.4 hydrocarbons from the laden absorbent stream, giving a C.sub.4 product gas stream d1, E) separating the C.sub.4 product stream d1 by extractive distillation with a butadiene-selective solvent into a stream e1 comprising butadiene and the selective solvent and a stream e2 comprising n-butenes; F) distilling the stream e1 comprising butadiene and the selective solvent into a stream f1 consisting essentially of the selective solvent and a stream f2 comprising butadiene, wherein stage Cb) comprises at least two compression stages Cba) and at least two cooling stages Cbb) configured in the form of quench columns, the cooling in the cooling stages being effected by direct contacting with a biphasic cooling medium having an aqueous phase and an organic phase.

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-butenes, water vapor, oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases; D) removing uncondensable and low-boiling gas constituents comprising oxygen and low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases, as gas stream d2 from the gas stream c2 by absorbing the C.sub.4 hydrocarbons comprising butadiene and n-butenes in an absorbent, giving an absorbent stream laden with C.sub.4 hydrocarbons and the gas stream d2, and then desorbing the C.sub.4 hydrocarbons from the laden absorbent stream, giving a C.sub.4 product gas stream d1, E) separating the C.sub.4 product stream d1 by extractive distillation with a butadiene-selective solvent into a stream e1 comprising butadiene and the selective solvent and a stream e2 comprising n-butenes; F) distilling the stream e1 comprising butadiene and the selective solvent into a stream f1 consisting essentially of the selective solvent and a stream f2 comprising butadiene, wherein stage Cb) comprises at least two compression stages Cba) and at least two cooling stages Cbb) configured in the form of quench columns, the cooling in the cooling stages being effected by direct contacting with a biphasic cooling medium having an aqueous phase and an organic phase.

Provided herein is a gas mixer for the safe mixing of a hydrocarbon containing gas with a gaseous oxidant. The gas mixer and method for mixing described includes a closed mixing vessel where bubbles of gas injected at the bottom of the vessel are mixed during their rise to the top of the vessel, forming a homogeneous mixture that can safely be removed. This simple design and method allows for safe mixing of gases and is applicable to catalytic oxidative processes such as oxidative dehydrogenation of paraffins where there is a risk of thermal runaway of reactions.

Provided herein is a gas mixer for the safe mixing of a hydrocarbon containing gas with a gaseous oxidant. The gas mixer and method for mixing described includes a closed mixing vessel where bubbles of gas injected at the bottom of the vessel are mixed during their rise to the top of the vessel, forming a homogeneous mixture that can safely be removed. This simple design and method allows for safe mixing of gases and is applicable to catalytic oxidative processes such as oxidative dehydrogenation of paraffins where there is a risk of thermal runaway of reactions.

The invention relates to a catalyst which comprises: a) a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium; and b) ceria particles having a crystallite size greater than 15 nanometers (nm); wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Further, the invention relates to a process for preparing a catalyst, which comprises mixing a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium with ceria particles having a crystallite size greater than 15 nanometers (nm), wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Still further, the invention relates to an alkane oxidative dehydrogenation and/or alkene oxidation process wherein such catalyst is used.

The invention relates to a catalyst which comprises: a) a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium; and b) ceria particles having a crystallite size greater than 15 nanometers (nm); wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Further, the invention relates to a process for preparing a catalyst, which comprises mixing a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium with ceria particles having a crystallite size greater than 15 nanometers (nm), wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Still further, the invention relates to an alkane oxidative dehydrogenation and/or alkene oxidation process wherein such catalyst is used.

The invention relates to a catalyst which comprises: a) a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium; and b) ceria particles having a crystallite size greater than 15 nanometers (nm); wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Further, the invention relates to a process for preparing a catalyst, which comprises mixing a mixed metal oxide of molybdenum, vanadium, niobium and optionally tellurium with ceria particles having a crystallite size greater than 15 nanometers (nm), wherein the amount of the ceria particles, based on the total amount of the catalyst, is of from 1 to 60 wt. %. Still further, the invention relates to an alkane oxidative dehydrogenation and/or alkene oxidation process wherein such catalyst is used.

A method of converting one or more alkanes to one or more alkenes that includes providing a first stream containing one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor containing one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide and acetylene; and providing the second stream to a second reactor containing a catalyst that includes CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor containing one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

A method of converting one or more alkanes to one or more alkenes that includes providing a first stream containing one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor containing one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide and acetylene; and providing the second stream to a second reactor containing a catalyst that includes CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor containing one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.