Patent ID: 9133226
Filing Date: 2015-09-15
Classification: B01D,B01J,C07F,Y02P

Abstract:
1. A process for recovering diphosphite-containing compounds from a feed mixture comprising diphosphite-containing compounds, organic mononitriles, organic dinitriles and a Lewis acid 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 a mixing section of a mixer-settler in the first stage of the multistage countercurrent liquid-liquid extractor; b) contacting the feed mixture with extraction solvent from the second stage of the multistage countercurrent liquid-liquid extractor in the mixing section of the mixer-settler of the first stage to form a mixed phase comprising a light phase and a heavy phase, wherein the light phase comprises extraction solvent and extracted diphosphite-containing compounds, and wherein the heavy phase comprises organic mononitrile and organic dinitriles; c) passing the mixture from step (b) to a settling section in the mixer-settler of the first stage, wherein the mixed phase separates into the light phase and the heavy phase; and d) introducing a Lewis base into the settling section of the first stage,