| 摘要 |
The invention relates to a method for producing 1,3-butadiene from n-butenes, comprising the following steps: A) providing a feed gas flow a, containing butanes, 1-butene, 2-butene, isobutene, and possibly 1,3-butadiene, from a fluid catalytic cracking plant; B) separating isobutene from the feed gas flow a, wherein a material flow b, containing butanes, 1-butene, 2-butene, and possibly 1,3-butadiene, is obtained; C) feeding the material flow b, containing butanes, 1-butene, and 2-butene, possibly a gas containing oxygen, and possibly water vapor into at least one dehydrogenation zone and dehydrogenating 1-butene and 2-butene into 1,3-butadiene, wherein a product gas flow c, containing 1,3-butadiene, butanes, 2-butene, water vapor, possibly oxygen, low-boiling hydrocarbons, high-boiling secondary components, possibly carbon oxides, and possibly inert gases, is obtained; D) cooling and compressing the product gas flow c, wherein at least an aqueous condensate flow d1 and a gas flow d2, containing 1,3-butadiene, butanes, 2-butene, water vapor, possibly oxygen, low-boiling hydrocarbons, possibly carbon oxides, and possibly inert gases, are obtained; Ea) separating non-condensable and low-boiling gas constituents, comprising low-boiling hydrocarbons, possibly oxygen, possibly carbon oxides, and possibly inert gases, as a gas flow e2 from the gas flow d2 by absorbing the C4 hydrocarbons, comprising 1,3-butadiene, butanes, and 2-butene, in an absorbent, wherein an absorbent flow loaded with C4 hydrocarbons and the gas flow e2 are obtained, and Eb) subsequently desorbing the C4 hydrocarbons from the loaded absorbent flow, wherein a C4 hydrocarbon flow e1 is obtained; F) separating the C4 hydrocarbon flow e1 by extractive distillation by means of a solvent selective for 1,3-butadiene into a material flow f1, containing 1,3-butadiene and the solvent, and a material flow f2, containing butanes and 2-butene, characterized in that at least 90% of the 1-butene contained in flow b is converted in step C) and a product flow f2 containing butanes and 2-butene is obtained in step F. |
