Materials and methods for the selective recovery of monovalent products from aqueous solutions using continuous ion exchange

Abstract

This document describes a process for the high purity and high concentration recovery of monovalent products via continuous ion exchange from aqueous solution for further down-stream purification.

What is claimed is: 
     
         1 . A method of recovering at least one monovalent product from an aqueous solution using continuous ion exchange comprising:
 a. adsorbing at least one monovalent product on an ion exchange resin at a pH of approximately the logarithm of a first acid dissociation constant of the at least one monovalent product;   b. eluting the at least one monovalent product from the ion exchange resin; and   c. charging adsorbent sites on the ion exchange resin with a sufficient amount of protons or proton donors to provide buffering capacity towards the pH of approximately the logarithm of the at least one monovalent product's first acid dissociation constant.   
     
     
         2 . The method of  claim 1 , wherein the at least one monovalent product is chosen from fatty acids, monoamines, and amino acids. 
     
     
         3 . The method of  claim 2 , wherein the monoamines comprise at least one of 4-aminobutyrate, 5-aminopentanoate, 6-aminohexanoate, and 7-aminoheptanoate. 
     
     
         4 . The method of  claim 1 , wherein the at least one monovalent product is eluted from the ion exchange resin with a solution comprising at least one compound chosen from ammonia, ammonium carbonate, and ammonium bicarbonate. 
     
     
         5 . The method of  claim 1 , comprising charging the adsorbent site on the ion exchange resin with an acidic solution. 
     
     
         6 . The method of  claim 5 , wherein the acidic solution comprises sulphuric acid. 
     
     
         7 . The method of  claim 1 , comprising charging the adsorbent sites on the ion exchange resin with an ammonium bicarbonate solution. 
     
     
         8 . The method of  claim 1 , further comprising at least one wash step after at least one of steps (a), (b), and (c). 
     
     
         9 . The method of  claim 8 , wherein the at least one wash step comprises washing the ion exchange resin with an aqueous solution. 
     
     
         10 . An apparatus for recovering at least one monovalent product from aqueous solutions comprising:
 a. an absorption zone to adsorb at least one monovalent product on an ion exchange resin at a pH of approximately the logarithm of a first acid dissociation constant of the at least one monovalent product;   b. an elution zone to elute the at least one monovalent product from the ion exchange resin; and   c. a proton buffer zone for charging adsorbent sites on the ion exchange resin with a sufficient amount of protons or proton donors to provide buffering capacity towards the pH of approximately the logarithm of the at least one monovalent product's first acid dissociation constant.   
     
     
         11 . The apparatus of  claim 10 , wherein the at least one monovalent product is chosen from fatty acids, monoamines, and amino acids. 
     
     
         12 . The apparatus of  claim 11 , wherein the monoamines comprise at least one of 4-aminobutyrate, 5-aminopentanoate, 6-aminohexanoate and 7-aminoheptanoate. 
     
     
         13 . The apparatus of  claim 10 , wherein the elution zone comprises at least one eluent chosen from ammonia, ammonium carbonate, and ammonium bicarbonate. 
     
     
         14 . The apparatus of  claim 10 , wherein the proton buffer zone comprises an ammonium bicarbonate solution for charging the adsorbent sites on the ion exchange resin. 
     
     
         15 . The apparatus of  claim 10 , wherein the proton buffer zone comprises an acidic solution for charging the adsorbent site on the ion exchange resin 
     
     
         16 . The apparatus of  claim 15 , wherein the acidic solution comprises sulphuric acid. 
     
     
         17 . The apparatus of  claim 10 , further comprising at least one wash step zone after at least one of zones (a), (b), and (c). 
     
     
         18 . The apparatus of  claim 17 , wherein the at least one wash step zone comprises an aqueous solution for washing the ion exchange resin.