Materials and methods for the selective recovery of multivalent products

Abstract

Described herein are processes and apparatus for the high purity and high concentration recovery of multivalent products via continuous ion exchange from aqueous solutions for further down-stream purification.

1 - 12 . (canceled) 
     
     
         13 . An apparatus for recovering multivalent products from aqueous solutions comprising one or more of the below zones;
 (a) an adsorption zone comprising an ion exchange resin, for adsorption of the the multivalent product comprising diamine chosen from putrescine, cadaverine, hexamethylenediamine, and heptamethylenediamine as principally a divalent species;   (b) a monovalent strip zone, for desorbing impurities and converting the adsorbed multivalent product to the monovalent state;   (c) a monovalent adsorption zone, for adsorbing recycled multivalent product recycled from a steam stripper; and   (d) an elution zone, for eluting the multivalent product using a concentrated ammonia, ammonium bicarbonate or ammonium carbonate solution.   
     
     
         14 - 16 . (canceled) 
     
     
         17 . The apparatus of  claim 13 , which is configured to selectively desorb impurities and (2) to convert the adsorbed multivalent product to principally the monovalent state by feeding a base or an acid at a concentration that allows the pH of the aqueous solution discharged from the resin to be approximately the pK a2  for cationic divalent products and to be approximately the pK a1  for anionic divalent products. 
     
     
         18 . The apparatus of  claim 17 , wherein the multivalent product at a pH of approximately first equivalence point is recycled to the ion exchange resin and concentrated through re-adsorption. 
     
     
         19 . The apparatus of  claim 13 , wherein (1) impurities are selectively desorbed and (2) the adsorbed multivalent product is converted to principally the monovalent state by recycling the multivalent product in principally the zero valence state, concentrating the multivalent product though re-adsorption. 
     
     
         20 . The apparatus of  claim 13 , wherein the multivalent product is eluted from the ion exchange resin with ammonia, ammonium bicarbonate and/or ammonium carbonate. 
     
     
         21 . The apparatus of  claim 18  or  claim 20 , where the eluted multivalent product is fed to a steam stripper, adjusting the pH of the multivalent product to approximately the first equivalence point. 
     
     
         22 . The apparatus of  claim 19  or  claim 20 , where the eluted multivalent product is fed to a steam stripper, adjusting the pH of the multivalent product to where the multivalent product is principally in the zero valence state. 
     
     
         23 . The apparatus of  claim 21 , where a fraction of the multivalent product recovered from the steam stripper is recycled to the ion exchange resin and concentrated through re-adsorption. 
     
     
         24 . The apparatus of  claim 13 , further comprising at least one elution wash zone after one or more of zones (a), (b), (c), and (d) using an aqueous solution. 
     
     
         25 . The apparatus of  claim 13 , wherein the monovalent strip zone and the monovalent adsorption zone are combined. 
     
     
         26 . The apparatus of  claim 22 , where a fraction of the multivalent product recovered from the steam stripper is recycled to the ion exchange resin and concentrated through re-adsorption.