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 C.sub.4 hydrocarbons 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; F) distilling the stream e1 into a stream f1 consisting essentially of the selective solvent and a stream f2 comprising butadiene; G) removing a portion of the aqueous phase of the cooling medium which circulates in step Ca) as aqueous purge stream g; H) distillatively separating the aqueous purge stream g into a fraction h1 and a fraction h2 depleted of organic constituents.

The present invention relates to a method for producing butadiene through an oxidative dehydrogenation reaction. The production method according to the present invention may easily regulate an input ratio between oxygen and nitrogen that are used as raw material, such that a loss may be minimized of butadiene that is included in a second fraction stream (purge stream) and discharged to outside of the system. Consequently, an economic competitiveness of the process, such as a reduced raw material cost and an improved productivity may be realized.

Disclosed are a composite oxide catalyst for preparing butadiene and a method of preparing the same. More particularly, a composite oxide catalyst, for preparing butadiene, including a metal composite oxide and AlPO.sub.4, and a method of preparing the same are disclosed.

According to the present disclosure, a composite oxide catalyst for preparing butadiene, which includes a specific binder material, prevents generation of ingredients with a high boiling point, has superior catalyst strength, catalytic activity and butadiene yield, and a method of preparing the same are provided.

Disclosed is a multi-component bismuth molybdate catalyst for production of butadiene which comprises bismuth, molybdenum and at least one metal having a monovalent, divalent or trivalent cation, and further comprises cesium and potassium and thus has advantages of improving conversion ratio, yield and selectivity of butadiene and of providing stability of process operation.

A method for producing 1,3-butadiene, including: (A) performing an oxidative dehydrogenation reaction between oxygen and a raw material gas including n-butene in the presence of a metal oxide catalyst, thereby obtaining a produced gas containing 1,3-butadiene; (B) washing the produced gas obtained in (A); (C) contacting the produced gas washed in (B) with a cooling medium to cool the produced gas; and (D) separating the produced gas cooled in (C) into molecular oxygen and inert gases, and other gases containing 1,3-butadiene, by selective absorption into an absorption solvent. In (B), the washing of the produced gas includes blowing the produced gas onto a liquid surface of a washing liquid so that the produced gas contacts the liquid surface of the washing liquid.

An exemplary embodiment of the present application provides a method for preparing butadiene, the method comprising a process of performing an oxidative dehydrogenation reaction by introducing a reactant comprising butene, oxygen, nitrogen, and steam into a reactor which is filled with a catalyst, in which during a first start-up of the oxidative dehydrogenation reaction, the oxygen is introduced into the reactor before the butene, or the oxygen is introduced into the reactor simultaneously with the butene.

A method for producing butadiene comprises a step of supplying a raw material gas containing 2-butene and an oxygen-containing gas containing molecular oxygen to a reactor filled with a catalyst to obtain a produced gas containing butadiene, wherein the catalyst contains a composite oxide containing molybdenum and bismuth, and a proportion of cis-2-butene in 2-butene in the raw material gas is 30 to 90 mol %.

An exemplary embodiment of the present application provides a method for preparing butadiene, the method comprising a process of performing an oxidative dehydrogenation reaction by introducing a reactant comprising butene, oxygen, nitrogen, and steam into a reactor which is filled with a catalyst, in which during a first start-up of the oxidative dehydrogenation reaction, the oxygen is introduced into the reactor before the butene, or the oxygen is introduced into the reactor simultaneously with the butene.

The invention provides non-naturally occurring microbial organisms having a butadiene pathway. The invention additionally provides methods of using such organisms to produce butadiene.

A process is presented for the production of butadiene from a mixture of butane/butene feed. The process provides high conversion of the feed by oxidative dehydrogenation of the feed. The process enables recovery of a good portion of heat inputted from the reaction effluent. The process overcomes equilibrium limitations by oxidative dehydrogenation of butane/butene feed to produce butadiene.