FLEXIBLE METHOD OF EXTRACTING BUTADIENE Russian patent published in 2017 - IPC C07C11/167 C07C7/04 C07C7/08 

FIELD: technological processes; chemistry.

SUBSTANCE: invention relates to versions of a system for extraction of 1,3-butadiene from a fraction of C₄ and in mode of high pressure, and in mode of low pressure. One version of system includes: a feedstock evaporation system at least for partial evaporation of hydrocarbon material containing butanes, butenes, 1,2-butadiene, 1,3-butadiene, acetylenes C₄, acetylenes C₃ and hydrocarbons C₅₊; extractive distillation system designed to bring evaporated hydrocarbon fraction into contact with a solvent for selective dissolution of part of hydrocarbon fraction to form (a) a solvent-rich fraction containing 1,3-butadiene, 1,2-butadiene, acetylenes C₄, acetylenes C₃, hydrocarbons C₅₊ and a first portion of butanes and butenes, and (b) vapour fraction containing a second portion of butanes and butenes; rectification column and final flushing device, intended for at least partial degassing of enriched solvent and extraction of first vapour fraction containing first portion of butanes and butenes, second vapour fraction containing acetylenes C₃ and C₄, 1,3-butadiene, 1,2-butadiene and hydrocarbons C₅₊, and bottom fraction containing partially degassed solvent; degasser and cooling column, intended for additional degassing of solvent and extraction of liquid fraction, containing degassed solvent, third vapour fraction containing at least one of acetylenes C₄ and 1,2-butadiene, and a fraction containing acetylenes C₄. System designed for extraction of 1,3-butadiene, can operate during extraction of 1,3-butadiene from fraction C₄ (a) with degassing device in high pressure mode and (b) with degassing device in low pressure mode.

EFFECT: possibility of operation at both high and low pressure provides additional flexibility of process.

19 cl, 1 dwg