Patent ID: 8829248

Claim:
A process for recovering a homogeneous catalyst, comprising (A) extracting a feed comprising: (i) a glycolic acid hydrogenation effluent, comprising (a) about 10 to about 99 weight percent ethylene glycol, about 0.5 to about 50 weight percent water, and about 0.5 to about 40 weight percent of one or more reaction by-products selected from glycolic acid, glycolic acid oligomers, ethylene glycol oligomers, glycolate esters, 1,2-propanediol, 1,2-butanediol, and polyols, each based on the total weight of said glycolic acid hydrogenation effluent; and (b) a catalyst composition comprising ruthenium and a tridentate ligand comprising at least one phosphine selected from 1,1,1-tris(diarylphosphinomethyl)alkanes and 1,1,1-tris(dialkylphosphinomethyl)alkanes; and (ii) additional water whereby said feed comprises about 5 to about 50 weight percent water based on the total weight of said glycolic acid hydrogenation effluent and said additional water; with a first extractant, comprising (i) a hydrophobic solvent selected from alkanols having from 4 to 20 carbon atoms, ketones having from 5 to 20 carbon atoms, esters having from 5 to 20 carbon atoms, ethers having from 5 to 20 carbon atoms, carboxylic acids having from 5 to 20 carbon atoms, and mixtures thereof; and (ii) optionally, a hydrophilic solvent; to form a first raffinate phase comprising a major amount of said ethylene glycol and a minor amount of said catalyst composition contained in said glycolic acid hydrogenation effluent and a first extract phase comprising a major amount of said catalyst composition and a minor amount of said ethylene glycol contained in said glycolic acid hydrogenation effluent; (B) separating said first raffinate phase and said first extract phase; and (C) recovering said catalyst composition from said first extract phase of step (B) by: (i) extracting said first extract phase of step (B) with a second extractant comprising water, ethylene glycol, glycolate esters of ethylene glycol, glycolic acid, glycolic acid oligomers, or mixtures thereof to form a second extract phase comprising a major amount of said catalyst composition contained in said first extract phase of step (B) and a second raffinate phase comprising a minor amount of said catalyst composition contained in said first extract phase of step (B); or (ii) distilling said first extract phase of step (B) to form a distillate comprising a major amount of said hydrophobic solvent contained in said first extract phase of step (B) and a bottoms comprising a major amount of said catalyst composition contained in said first extract phase of step (B).