SIMPLIFIED METHOD FOR ISOLATING PURE 1,3-BUTADIENE Russian patent published in 2022 - IPC C07C7/04 C07C7/08 C07C11/167 B01D3/14 B01D3/40 

FIELD: chemical processes.

SUBSTANCE: invention relates to a method for isolating pure 1,3-butadiene from crude C₄ fraction, characterised by a preset maximum content of at least one low-boiling component and a preset maximum content of 1,2-butadiene, respectively, as calculated for 1,3-butadiene, wherein: a) the crude C₄ fraction is directed to a pre-distillation column equipped with a partition oriented in the longitudinal direction thereof, wherein the low-boiling fraction containing C₃ hydrocarbons is collected from the pre-distillation column as an overhead stream, the high-boiling fraction as a bottoms stream, and the purified C₄ fraction as a lateral stream, wherein the purified C₄ fraction has a content of said at least one low-boiling component, as calculated for 1,3-butadiene, equal to or less than said maximum content of said at least one low-boiling component, and said maximum content of 1,2-butadiene therein is 25 parts per mil., as calculated for 1,3-butadiene, b) the purified C₄ fraction is subjected to at least one extractive distillation with a selective solvent, wherein at least one fraction containing butanes and butenes is produced, as well as a fraction of pure 1,3-butadiene.

EFFECT: method provides a possibility of eliminating the need to use a finishing distillation column.

15 cl, 1 dwg, 1 ex, 2 tbl