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 low-boiling gas components comprising oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally 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 absorption medium, wherein an absorption medium stream loaded with C.sub.4 hydrocarbons and the gas stream d2 are obtained, and Db) subsequently desorbing the C.sub.4 hydrocarbons from the loaded absorption medium stream in a desorption column, wherein a C.sub.4 product gas stream d1 is obtained, Dc) separating off the steam condensate from the absorption medium in a phase separator and vaporizing it in a steam generator and providing it again as stripping gas in the desorption column,
wherein, the steam condensate before the vaporization in a steam generator, is subjected to a pretreatment in a further method step.

A method for producing butadiene comprises a step of obtaining a product gas containing butadiene, by feeding a raw-material gas containing straight-chain butene and an oxygen-containing gas containing molecular oxygen to a reactor and performing oxidative dehydrogenation reaction in the presence of a catalyst, wherein the catalyst comprises a composite oxide containing molybdenum and bismuth, and the concentration of hydrocarbons having 5 or more carbon atoms in the raw-material gas is 0.05 mol % to 7.0 mol %.

A method for producing diene comprises a step 1 of obtaining a straight chain internal olefin by removing a branched olefin from a raw material including at least the branched olefin and a straight chain olefin; and a step 2 of producing diene from the internal olefin by oxidative dehydrogenation using a first catalyst and a second catalyst, and the first catalyst has a complex oxide including bismuth, molybdenum and oxygen, and the second catalyst includes at least one selected from the group consisting of silica and alumina.

[Task] Provided is a manufacturing method of butadiene that can reduce carbon dioxide emissions.

[Solution] A manufacturing method of butadiene includes an electrolytic reduction process 2 that produces ethylene and oxygen from carbon dioxide and water as a raw material by electrolytic reduction, a butene producing process 3 that produces butene by dimerizing the ethylene produced in the electrolytic reduction process, a mixing process 4 that prepares a mixed gas by mixing the oxygen produced in the electrolytic reduction process, the butene produced in the butene producing process, and air, and a butadiene producing process 5 that produces butadiene by heating the mixed gas and oxidatively dehydrogenating the butene, wherein carbon dioxide by-produced in the butadiene producing process is used as a portion of the raw material in the electrolytic reduction process.

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-boiling gas components comprising oxygen, low-boiling hydrocarbons, possibly carbon oxides and possibly inert gases as gas stream d2 from the gas stream c2 by absorbing the C.sub.4 hydrocarbon-comprising butadiene and n-butenes in an absorbent, wherein an absorbent stream loaded with C.sub.4 hydrocarbons and the gas stream d2 are obtained, and Db) subsequent desorption of the C.sub.4 hydrocarbons from the loaded absorbent stream in a desorption column, wherein a C.sub.4 product gas stream d1 is obtained,
wherein a polymerization inhibitor is added in step Db) at the column head of the desorption column.

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.

Provided are a method of preparing a multicomponent bismuth-molybdenum composite metal oxide catalyst, and a multicomponent bismuth-molybdenum composite metal oxide catalyst prepared thereby. According to the preparation method, since the almost same structure as that of a typical quaternary bismuth-molybdenum catalyst may be obtained by performing two-step co-precipitation, i.e., primary and secondary co-precipitation, of metal components constituting the catalyst, the reduction of catalytic activity due to the deformation of the structure of the catalyst may be suppressed. Also, since the multicomponent bismuth-molybdenum composite metal oxide catalyst may adjust the number of lattice oxygens consumed during a reaction to increase the catalytic activity, the multicomponent bismuth-molybdenum composite metal oxide catalyst may reduce the formation of by-products and may improve the conversion rate of reactant and the yield of desired product in a catalytic reaction process using the above catalyst, particularly, a catalytic reaction process under a relatively low temperature condition.

An isomerization catalyst for isomerizing a first straight-chain olefin to a second straight-chain olefin different therefrom in a double bond position in the presence of 20 ppm by volume or more of molecular oxygen more and/or water, comprising: Si; Al; and at least one metallic element selected from the Group 1 elements and the Group 2 elements, wherein the molar ratio of Si to Al (Si/Al) is 100 or less.

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.

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