METHOD FOR PREPARING 1.3-BUTADIENE FROM N-BUTENES BY OXIDATIVE DEHYDRATION

• Main Authors: JOSCH, Jan Pablo, KARANIKOULIS, Georgios, WELLENHOFER, Anton, MOSSBACHER, Claudia, WENNING, Ulrike, TOEGEL, Christine, REYNEKE, Hendrik, HAMMEN, Oliver
• Format: Patent
• Language: English; French; German
• Published: 21.11.2018
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention relates to a process for preparing butadiene from n-butenes, comprising the steps of: A) providing a feedstock gas stream a containing n-butenes; B) feeding the feedstock gas stream a containing n-butenes and a gas containing oxygen into at least one oxidative dehydrogenation zone and oxidatively dehydrogenating n-butenes to butadiene, resulting in a product gas stream b containing butadiene, unreacted n-butenes, steam, oxygen, low-boiling hydrocarbons, high-boiling secondary components, optionally carbon oxides and optionally inert gases; Ca) cooling the product gas stream b by bringing same in contact with a coolant, and condensing at least some of the high-boiling secondary components; Cb) compressing the remaining product gas stream b in at least one compression stage, resulting in at least one aqueous condensate stream c1 and one gas stream c2 containing butadiene, n-butenes, steam, oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases; Da) removing non-condensable and low-boiling gas constituents comprising oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases as a gas stream d2 from gas stream c2 by absorbing the C4 hydrocarbons comprising butadiene and n-butenes in an absorbent, resulting in an absorbent stream laden with C4 hydrocarbons and gas stream d2, and Db) subsequently desorbing the C4 hydrocarbons from the laden absorbent stream in a desorption column, resulting in a C4 product gas stream d1. The invention is characterized in that a polymerization inhibitor is added in step Db) at the column head of the desorption column.