US  8,709,376  B2  44  43  from 5 to 16 carbon  atoms, an  organophosphorus  acid con› taining from 5 to  16 carbon atoms,  an alkanol containing  6 to  12 carbon atoms,  or a  combination thereof,  to form a washed  aqueous raffinate  phase and a organic  wash extract phase,  wherein the weight  ratio of the wash  solvent to the aqueous  raffinate phase is  about 0.1:1 to about  1:1;  separating the washed  aqueous raffinate  and organic wash  extract phases, and  combining the organic  wash extract phase  with the extrac› tion solvent of step  (A) or with the organic  extract phase  of step (B).  13.  The process according  to claim  12  wherein the wash  solvent comprises  propane, butane,  hexane, heptane,  decane,  ~ethylcyclohexane,  methylene chloride,  chlorobenzene,  d1chlorobenzene,  1,2-dichloroethane,  benzene,  toluene,  xylene, isoparaffinic  mixed hydrocarbons  having a boiling  range between 90  and 325°  C., or a  combination thereof- and  the ~ash _modifier  comprises n-pentanoic  acid, 2-meth;lbu› tanmc acid,  3-methylbutanoic  acid, hexanoic acid,  perfluo› rooctanoic acid,  2-ethylbutanoic  acid, heptanoic  acid,  octanoic  acid,  2-ethylhexanoic  acid,  pelargonic  acid,  nonanoic acid, decanoic  acid, !auric acid,  palmitic acid, bis  (2-ethylhexyl)hydrogen  phosphate, n-hexanol,  2-ethylhex› anol,  2-ethylbutanol, n-octanol,  isooctanol, n-decanol,  isode› canol, or a combination  thereof.  14.  A process for  recovering  an acid catalyst from  aqueous  glycolic acid, comprising  (A!  extracting an aqueous  glycolic acid mixture,  compris› mg  (i) about 70 to about  90 weight percent  glycolic acid,  based on the total  weight of the aqueous  glycolic acid  mixture, and  (ii) about 1 to about  10 weight percent  of an acid catalyst  comprising sulfuric  acid,  methanesulfonic  acid  methanedisulfonic  acid,  methanedisulfonic  acid bi~  (methylsulfonyl)methanesulfonic  acid,  trifluo› romethanesulfonic  acid,  1,  1,2,2-tetrafluoroethane› sulfonic acid, or  a  combination thereof- with an extraction  solvent, comprising  (i) about 5 to about  45 weight percent,  based on the total  weight of the extraction  solvent, of a tertiary  amine  comprising  tris(2-ethylhexyl)amine,  tris(2-ethylbu› tyl)amine, trioctylamine,  triisooctylamine,  triisode- cyl amine,  tridodecylamine,  tridecylamine, dioctyl› decylamine, didecyloctylamine,  or a  combination  thereof;  (ii) about 5 to about  45 weight percent  of a modifier  comprising 2-ethylhexanoic  acid, !auric acid,  bis(2- ethylhexyl)hydrogen  phosphate, perfluorooctanoic  acid, or a combination  thereof, wherein  the weight  ratio of the modifier  to the tertiary amine  is about 1: 1  to about 5:1; and  (iii) about 10 to  about 90 weight  percent of a diluent  comprising hexane,  heptane, decane,  methylcyclo› hexane, benzene,  toluene, xylene,  isoparaffinic mixed  hydrocarbons having  a boiling range between  90 and  325°  C., or a  combination thereof;  to form an aqueous  raffinate phase comprising  a major  amount of the glycolic  acid contained in  the aqueous  *  *  *  *  *  18.  The process according  to claim  17  wherein the aqueous  formaldehyde extract  comprises about  0.5 to about 1 0 weight  percent sulfuric acid,  based on the total  weight of the aqueous  formaldehyde extract.  17.  The process according  to claim  16  wherein the acid  catalyst comp~ses  sulfuric acid; the  amine comprises  tris(2- ethylhexyl)amme;  the modifier comprises  2-ethylhexanoic  acid; the diluent  comprises hexane,  heptane, decane,  or a  combination thereof;  the wash solvent  comprises hexane,  he~~ane, decane,  isoparaffinic mixed  hydrocarbons having  a  b01lmg range between  90 and 325°  C., or a  combination  thereof; the wash  modifier comprises  2-ethylhexanoic  acid,  n-hexanol, n-decanol,  or a  combination thereof- and the  weight ratio of the  modifier to the tertiary  amine is’about 2:1  to about 4:1.  16.  The process according  to claim  15  wherein the aqueous  formaldehyde solution  of step  (C)  comprises about  40 to  about 55 weight  percent formaldehyde  and the aqueous  form› aldehyde extract  of step  (C)  is passed to the  glycolic acid  process.  15.  The process according  to claim  14  wherein the aqueous  glycoli~ acid mixture  is prepared by process  comprising  car› bonylat10n  of  formaldehyde  in the presence of  a sulfuric acid  catalyst.  (F) combining the  organic wash extract  phase with the  extraction solvent  of step (A) or with  the organic extract  phase of step (B).  (E) separating the  washed aqueous  raffinate and organic  wash extract phases;  and  (D) ~ontacting the  aqueous raffinate  phase from step  (B)  with a wash solvent  comprising about  80 to about 100  weight percent,  based on the total  weight of the wash  solvent, of a wash  diluent comprising  hexane, heptane,  decane,  methylcyclohexane,  benzene, toluene,  xylene,  isoparaffinic mixed  hydrocarbons having  a boiling range  between 90 and  325°  C., or a  combination thereof- and  about  O  to about 20 weight  percent of a wash  modifier  comprising 2-ethylhexanoic  acid, !auric acid,  bis(2-eth› ylhexyl)hydrogen  phosphate, 2-ethylhexanol,  2-eth› ylbutanol, n-hexanol,  n-octanol, n-decanol,  or a combi› nation thereof, to  form a washed aqueous  raffinate phase  an~ an organic wash  extract phase, wherein  the weight  rat10 of the wash  solvent to the aqueous  raffinate phase is  about 0.1:1 to about  1:1;  (C)  extracting the organic  extract phase from  step (B) with  an aqueous  formaldehyde solution,  comprising about  35  to about 85 weight  percent formaldehyde,  based on the  total weight of the  aqueous formaldehyde  solution, to  fon_n an aqueous  formaldehyde extract  comprising  a  maJor amount of  the acid catalyst  contained in the  organic extract phase  from step  (B)  and an organic raf› finate phase comprising  a minor amount  of the acid  catalyst contained  in the organic extract  phase;  (B) separating the  aqueous raffinate  and organic extract  phases;  glycol!c. acid mi:-ture  and an organic  extract phase  c~mpn_smg  a maJor amount  of the acid catalyst  con› tamed m the aqueous  glycolic acid mixture• 