# US 2013/0253232 A1 · Methods for recovery and recycle of ruthenium homogenous catalysts

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- Number: US 2013/0253232 A1
- Document ID: US20130253232A1
- Status: Published application
- Kind: A1
- Application number: 13/896,706
- Filed: 2013-05-17
- Published: 2013-09-26
- Earliest claimed: 2010-08-18
- Assignees: Eastman Chemical Company
- Applicants: Eastman Chemical Company
- Inventors: Scott Donald Barnicki; Jeffrey Scott Kanel; Kenneth Wayne Hampton, JR.
- Web page: https://patentgrep.com/patent/US20130253232A1

## CPC

- B01J 31/2404: {Cyclic ligands, including e.g. non-condensed polycyclic ligands, the phosphine-P atom being a ring member or a substituent on the ring}
- B01J 31/24: Phosphines {, i.e. phosphorus bonded to only carbon atoms, or to both carbon and hydrogen atoms, including e.g. sp2-hybridised phosphorus compounds such as phosphabenzene, phosphole or anionic phospholide ligands}
- B01J 31/2409: {with more than one complexing phosphine-P atom}
- B01J 31/4053: {with recovery of phosphorous catalyst system constituents}
- C07C 29/149: with hydrogen or hydrogen-containing gases
- C07C 29/86: by liquid-liquid treatment
- B01J 2531/0238: Complexes comprising multidentate ligands, i.e. more than 2 ionic or coordinative bonds from the central metal to the ligand, the latter having at least two donor atoms, e.g. N, O, S, P
- B01J 2531/821: Ruthenium
- Y02P 20/52: using catalysts, e.g. selective catalysts
- Y02P 20/582: Recycling of unreacted starting or intermediate materials
- Y02P 20/584: Recycling of catalysts
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

Disclosed is a process for the extractive recovery of a homogeneous ruthenium catalyst from the reaction product of the hydrogenation of glycolic acid, glycolate esters, and/or glycolic acid oligomers with an extractant comprising a hydrophobic solvent and an optional hydrophilic solvent. The ruthenium catalyst, which can include 1,1,1-tris(diaryl- or dialkylphosphinomethyl)alkane ligands, can be recovered from the hydrophobic extract phase by back extraction with a hydrophilic solvent and recycled to a process for the preparation of ethylene glycol by the hydrogenation of glycolic acid and glycolic acid derivatives.

## Claims

### Claim 1

A process for recovering a homogeneous catalyst, comprising
(A) contacting an aqueous mixture comprising glycolic acid, glycolate esters, methyl glycolate, oligomers of glycolic acid, or mixtures thereof, with hydrogen in the presence of a catalyst composition comprising ruthenium and tris-1,1,1-(diphenylphosphinomethyl)ethane to form a glycolic acid hydrogenation product comprising about 50 to about 90 weight percent, based on the total weight of said glycolic acid hydrogenation product, ethylene glycol, about 0.5 to about 25 weight percent water, and about 0.5 to about 30 weight percent of one or more reaction by-products selected from glycolic acid, oligomers of glycolic acid, and glycolate esters of ethylene glycol, and said catalyst composition;
(B) extracting said glycolic acid hydrogenation product with a first extractant, comprising about 60 to 100 weight percent, based on the total weight of said first extractant, 2-ethylhexanol and about 0 to about 40 weight percent of a hydrocarbon having 5 to 20 carbon atoms to form a first raffinate phase comprising a major amount of said ethylene glycol contained in said glycolic acid hydrogenation product and a first extract phase comprising a major amount of said catalyst composition contained in said glycolic acid hydrogenation product;
(C) separating said first raffinate and extract phases;
(D) extracting said first extract phase from step (C) 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 from step (C) and a second raffinate phase comprising a minor amount of said catalyst composition contained in said first extract phase; and
(E) combining said second extract phase with said aqueous mixture of glycolic acid of step (A).

### Claim 2 (depends on 1)

The process according to claim 1 further comprising combining said second raffinate phase of step (D) with said first extractant of step (B), or distilling said second raffinate phase of step (D) to produce a hydrophobic solvent distillate and combining said hydrophobic solvent distillate with said first extractant of step (B).