# US 10,308,569 B2 · Process for preparing 1,3-butadiene from n-butenes by oxidative dehydrogenation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,569 B2 - Document ID: US10308569B2 - Status: Granted - Kind: B2 - Application number: 15/514,077 - Filed: 2015-09-14 - Published: 2018-01-04 - Granted: 2019-06-04 - Earliest claimed: 2014-09-26 - Assignees: BASF SE; Linde Aktiengesellschaft - Applicants: BASF SE; Linde AG - Inventors: Jan Pablo Josch; Philipp Grüne; Regina Benfer; Maximilian Vicari; Andre Biegner; Gergor Bloch; Heinz Boelt; Hendrik Reyneke; Christine Toegel; Ulrike Wenning - Web page: https://patentgrep.com/patent/US10308569B2 ## CPC - C07C 5/48: with oxygen as an acceptor - B01D 3/40: Extractive distillation - C07C 7/005: {Processes comprising at least two steps in series} - C07C 7/08: by extractive distillation - C07C 7/11: by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids - C07C 5/333: Catalytic processes - C07C 7/05: with the aid of auxiliary compounds - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## 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-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 C4 hydrocarbons comprising butadiene and n-butenes 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 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. ## Claims ### Claim 1 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 to form a cooled product gas stream depleted of high-boiling secondary components, the cooling medium being at least partly recycled and, having an aqueous phase and an organic phase, Cb) compressing the cooled product gas stream 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, and then desorbing the C4 hydrocarbons from the absorbent stream laden with C4 hydrocarbons giving C4 product gas stream d1, E) separating the C4 product gas 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 the step Cb) comprises at least two compression stages Cba) and at least two cooling stages Cbb) configured in the form of quench columns, cooling in the at least two cooling stages Cbb) being effected in cooling zones by direct contacting the cooled products gas stream with a biphasic cooling medium having an aqueous phase and an organic phase formed from 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 wherein in the at least two cooling stages Cbb), a mass ratio of the aqueous phase to the organic phase in the biphasic cooling medium when it is fed into the cooling zones prior to the contacting with the cooled product gas stream is from 0.15:1 to 10:1 and wherein a coolant having an aqueous phase and an organic phase is fed continuouslyor discontinuously into the at least two compression stages Cba), and wherein the coolant is fed into anintake line of at least one compressor of the at least two compression stages Cba) or into a housing of at leastone compressor of the at least two compression stages Cba). ### Claim 2 (depends on 1) The process according to claim 1, wherein the step Cb) comprises at least three compression stages Cba) and at least three cooling stages Cbb). ### Claim 3 (depends on 2) The process according to claim 2, wherein the step Ca) is conducted in three stages Ca1), Ca2) and Ca3) in three cooling zones. ### Claim 4 (depends on 3) The process according to claim 3, wherein the step D) comprises stages Da) to Dc): Da) absorbing the C4 hydrocarbons comprising butadiene and n-butenes in a high-boiling absorbent, giving the absorbent stream laden with C4 hydrocarbons and the gas stream d2, Db) removing oxygen from the absorbent stream laden with C4 hydrocarbons from the stage Da) by stripping with an uncondensable gas stream, and Dc) desorbing the C4 hydrocarbons from the absorbent stream laden with C4 hydrocarbons, giving the C4 product gas stream d1 comprising less than 100 ppmw of oxygen.