| abstract |
The invention relates to a method for producing 1,3-butadiene from n-butenes, comprising the following steps: A) obtaining a stream a of a source gas containing butane, 1-butene, 2-butene, isobutene and, if necessary, 1,3-butadiene from fluidized bed catalytic cracking units; B) separating isobutene from stream a of the source gas, whereby a stream b of a substance containing butane, 1-butene, 2-butene and, if necessary, 1,3-butadiene is obtained; C) feeding stream b of a substance containing butane, 1-butene and 2-butene, and optionally an oxygen-containing gas, as well as, if necessary, water vapor to at least one dehydrogenation zone and dehydrogenation of 1-butene and 2-butene obtaining 1,3-butadiene, whereby a stream from a gas product containing 1,3-butadiene, butane, 2-butene, water vapor, optionally oxygen, low boiling hydrocarbons, high boiling point components, optionally carbon oxides and, inert gases if necessary; D) cooling and compressing the gas stream from the product, wherein at least one condensate water stream d1 and one d2 gas stream containing 1,3-butadiene, butane, 2-butene, water vapor, optionally oxygen, low boiling hydrocarbons are obtained, if necessary, carbon oxides and, if necessary, inert gases; Ea) separating non-condensable and low-boiling gas components containing low-boiling hydrocarbons, if necessary oxygen, carbon oxides and, if necessary, inert gases, as gas stream e2 from gas stream d2 by absorption of C-hydrocarbons containing 1.3 -butadiene, butane and 2-butene in the absorbent, whereby an absorbent stream saturated with C-hydrocarbons and a gas stream e2 and Eb are obtained, followed by desorption of C-hydrocarbons from the saturated absorbent stream, whereby a stream of e1 C-hydrocarbons is obtained; F) separating the e1-C-hydrocarbon stream by extractive distillation with a 1,3-butadiene selective solvent into a substance stream f1 containing 1,3-butadiene and a selective solvent, and a substance stream f2 containing butane and 2-butene, characterized in that in step C) at least 90% of the 1-butene contained in stream b is converted, and in step F, a substance stream f2 containing butane and 2-butene is obtained. |