Patent ID: 9744475
Date: 2017-08-29
CPC Classifications: B01D,C07C

Claim:
1. A system for recovering 1,3-butadiene from a C 4 fraction, comprising: a flow conduit for feeding a hydrocarbon fraction containing butanes, butenes, 1,2-butadiene, 1,3-butadiene, C the extractive distillation system for contacting the hydrocarbon fraction with a solvent in the extractive distillation system to selectively dissolve a portion of the hydrocarbon fraction; a flow conduit for recovering a vapor fraction comprising a first portion of the butanes and the butenes from the extractive distillation system; a flow conduit for recovering an enriched solvent fraction comprising the 1,3-butadiene, the 1,2-butadiene, C a flow conduit for feeding the enriched solvent fraction to a rectifier; the rectifier for at least partially degassing the enriched solvent; a flow conduit for recovering a second portion of the butanes and butenes from the rectifier as an overheads fraction; a flow conduit for recovering the C a flow conduit for recovering a partially degassed solvent comprising 1,2-butadiene and C a flow conduit for feeding at least a portion of the partially degassed solvent to a degasser; the degasser for further degassing the solvent; a flow conduit for recovering an overheads fraction comprising at least one of C a flow conduit for recovering a side draw fraction comprising the C a flow conduit for recovering a bottoms fraction comprising degassed solvent from the degasser; a liquid ring compressor for compressing the degasser overheads fraction; and a flow conduit for recycling at least a portion of the compressed degasser overheads fraction to the rectifier.