Extraction solvent control for reducing stable emulsions

摘要

Disclosed herein are methods for recovering diphosphite-containing compounds from mixtures comprising organic mononitriles and organic dinitriles, using liquid-liquid extraction. Also disclosed are treatments to enhance extractability of the diphosphite-containing compounds.

主权项

1. A process for recovering diphosphite-containing compounds from a feed mixture comprising diphosphite-containing compounds, organic mononitriles and organic dinitriles in a multistage countercurrent liquid-liquid extractor with extraction solvent comprising aliphatic hydrocarbon, cycloaliphatic hydrocarbon or a mixture of aliphatic and cycloaliphatic hydrocarbon, said process comprising:
a) flowing the feed mixture to the first stage of the multistage countercurrent liquid-liquid extractor; and b) contacting the feed mixture with extraction solvent in the multistage countercurrent liquid-liquid extractor,
wherein the first stage of the multistage countercurrent liquid-liquid extractor comprises a mixing section and a settling section, wherein a light phase separates from a heavy phase in the settling section, wherein the light phase comprises extraction solvent and extracted diphosphite-containing compounds, wherein the heavy phase comprises organic mononitriles and organic dinitriles, wherein a first portion of the light phase is withdrawn from the settling section and treated to recover diphosphite-containing compounds extracted into the light phase, and wherein a second portion of the light phase is withdrawn from the settling section and recycled to the mixing section of the first stage of the multistage countercurrent liquid-liquid extractor.