METHOD OF EXTRACTING BUTADIENE Russian patent published in 2016 - IPC C07C7/08 C07C11/167 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for extraction of 1,3-butadiene from C₄ fraction. Method involves: feeding a hydrocarbon fraction containing butanes, butenes,

1,2-butadiene, 1,3-butadiene, C₄ acetylenes, C₃ acetylenes and C_{5 +} hydrocarbons into a plant for extractive distillation; making a contact of the hydrocarbon fraction with a solvent in the plant for extractive distillation for selective dissolving part of the hydrocarbon fraction; extraction of a steam fraction containing the first part of butanes and butenes from the extractive distillation plant; extraction of enriched solvent fraction containing 1,3-butadiene, 1,2-butadiene, C₄ acetylenes, C₃ acetylenes, C_{5 +} hydrocarbons and the second part of butanes and butenes; feeding the enriched solvent fraction into a rectifier for at least partial degasification of the enriched solvent; extraction of the second part of butanes and butenes from the rectifier in the form of the head fraction; extraction of C₃ and C₄ acetylenes, 1,3-butadiene, 1,2-butadiene and C_{5 +} hydrocarbons from the rectifier in the form of the side fraction; extraction of partially degassed solvent containing 1,2-butadiene and C₄ acetylenes from the rectifier in the form of the bottom fraction; feeding at least part of the partially degassed solvent into a degasifier for additional degassing of the solvent; extraction of the head fraction containing at least one of the C₄ acetylenes and 1,2-butadiene from the degasifier; extraction of the side fraction containing C₄ acetylenes from the degasifier; extraction of the bottom fraction containing degassed solvent from the degasifier; compression of the degasifier head fraction by a compressor with a fluid ring; and recirculation of at least part of compressed head fraction of the degasifier into the rectifier. Invention also relates to the device.

EFFECT: use of the fluid-ring compressor reduces capital and operating costs similarly to the non-compressor version simultaneously reducing risks associated with increased operating temperatures and pressures as in use of the non-compressor version.

25 cl, 1 tbl, 5 dwg