Separation method

Abstract

The invention relates to a process of recovering galactose from a solution derived from plant-based biomass. In the process of the invention, the starting solution is subjected to one or more chromatographic fractionation steps, which may carried out with a strongly basic anion exchange resin and optionally with a strongly acid cation exchange resin, in any desired sequence, followed by recovering at least one fraction enriched in galactose. The galactose fraction thus obtained is further purified by crystallization to obtain crystalline galactose. The invention also relates to non-animal derived crystalline D-galactose.

1 . A process of recovering galactose from a solution, which is derived from plant-based biomass, comprising 
 subjecting said solution to one or more chromatographic fractionations,    recovering at least one fraction enriched in galactose,    subjecting said at least one fraction enriched in galactose to crystallization, and    recovering a plant-based crystalline galactose product.    
     
     
         2 . A process as claimed in  claim 1 , wherein said one or more chromatographic fractionations comprise one or more chromatographic fractionation steps using a column filling material selected from strongly basic anion exchange resins.  
     
     
         3 . A process as claimed in  claim 2 , wherein the ion form of said strongly basic anion exchange resin is selected from SO 4   2− , SO 3   2− , HSO 3   −  and Ch 3 COO − .  
     
     
         4 . A process as claimed in  claim 2 , wherein said one or more chromatographic fractionations comprise one or more chromatographic fractionation steps using a column filling material selected from strongly basic anion exchange resins in HSO 3   −  form.  
     
     
         5 . A process as claimed in  claim 4 , wherein said one or more chromatographic fractionations comprise two chromatographic fractionation steps with a resin in HSO 3   −  form.  
     
     
         6 . A process as claimed in  claim 1 , wherein said one or more chromatographic fractionations comprise one or more chromatographic fractionation steps using a column filling material selected from strongly acid cation exchange resins.  
     
     
         7 . A process as claimed in  claim 6 , wherein the ion form of said strongly acid cation exchange resin is selected from Ba 2+ , Pb 2+ , Ca 2+  and Sr 2+ .  
     
     
         8 . A process as claimed in  claim 1 , wherein said one or more chromatographic fractionations comprise one or more chromatographic fractionation steps using a column filling material selected from strongly basic anion exchange resins and one or more chromatographic fractionation steps using a column filling material selected from strongly acid cation exchange resins, in any desired sequence.  
     
     
         9 . A process as claimed in  claim 1 , wherein the chromatographic fractionation provides a galactose fraction having a purity of more than 38% galactose on RDS.  
     
     
         10 . A process as claimed in  claim 1 , wherein the chromatographic fractionation provides a galactose fraction having a purity of 38 to 95% galactose on RDS.  
     
     
         11 . A process as claimed in  claim 1 , wherein the chromatographic fractionation provides a yield of galactose of 35 to 95%.  
     
     
         12 . A process as claimed in  claim 1 , wherein the crystallization is carried out using a solvent selected from water and a mixture of water and alcohol as the crystallization solvent.  
     
     
         13 . A process as claimed in  claim 12 , wherein the crystallization solvent is a mixture of ethanol and water.  
     
     
         14 . A process as claimed in  claim 12 , wherein the crystallization solvent is water.  
     
     
         15 . A process as claimed in  claim 1 , wherein said crystallization is carried out from a galactose solution having a purity of more than 38% galactose on RDS.  
     
     
         16 . A process as claimed in  claim 1 , wherein said crystallization of galactose is carried out from a galactose solution having a purity of 38 to 95% galactose on RDS.  
     
     
         17 . A process as claimed in  claim 1 , wherein the crystallization provides a crystalline galactose product having a purity of more than 90% galactose on DS.  
     
     
         18 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having a purity of more than 95% on DS.  
     
     
         19 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having a purity of more than 98% on DS.  
     
     
         20 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having a purity of more than 99.5% on DS.  
     
     
         21 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having a maximum content of D-glucose of 0.50% on DS.  
     
     
         22 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having a maximum content of D-glucose of 0.30%.  
     
     
         23 . A process as claimed in  claim 1 , wherein the crystallization provides crystalline galactose having an impurity profile comprising at least one sugar selected from xylose, arabinose, rhamnose and mannose.  
     
     
         24 . A process as claimed in  claim 23 , wherein the crystallization provides crystalline galactose, where the impurity profile comprises at least one of said sugars in an amount of 0.03% on DS or more.  
     
     
         25 . A process as claimed in  claim 24 , wherein the crystallization provides crystalline galactose, where the impurity profile comprises arabinose in an amount of 0.03% on DS or more.  
     
     
         26 . A process as claimed in  claim 24 , wherein the crystallization provides crystalline galactose, where the impurity profile comprises mannose in an amount of 0.03% on DS or more.  
     
     
         27 . A process as claimed in  claim 23 , wherein the crystallization provides crystalline galactose, where the impurity profile comprises at least one of said sugars in an amount of 0.10% or more.  
     
     
         28 . A process as claimed in  claim 1 , wherein the process further comprises one or more purification steps selected from membrane filtration, ion exchange, evaporation and filtration carried out before, after or between said chromatographic fractionation step/steps.  
     
     
         29 . A process as claimed in  claim 1 , wherein the process further comprises crystallization between said chromatographic fractionation steps.  
     
     
         30 . A process as claimed in  claim 29 , wherein said crystallization comprises precipitation crystallization of xylose.  
     
     
         31 . A process as claimed in  claim 1 , wherein said solution derived from plant-based biomass is selected from a plant-based hemicellulose hydrolysate and a plant-based hemicellulose extract.  
     
     
         32 . A process as claimed in  claim 31 , wherein said plant-based hemicellulose hydrolysate is hydrolysate derived from wood material.  
     
     
         33 . A process as claimed in  claim 31 , wherein said plant-based hemicellulose hydrolysate is a hydrolysate derived from softwood or hardwood.  
     
     
         34 . A process as claimed in  claim 1 , wherein said soluton derived from plant-based biomass is a spent liquor obtained from a pulping process.  
     
     
         35 . A process as claimed in  claim 34 , wherein said spent liquor obtained from a pulping process is a spent sulphite pulping liquor.  
     
     
         36 . A process as claimed in  claim 35 , wherein said spent sulphite pulping liquor is a spent sulphite pulping liquor recovered after the separation of the main part of xylose.  
     
     
         37 . A process as claimed in  claim 1 , wherein said solution derived from plant-based biomass contains galactose and one or more further sugars selected from xylose, arabinose, mannose and rhamnose.  
     
     
         38 . A process as claimed in  claim 1 , wherein said solution derived from plant-based biomass contains galactose and one or more further sugars selected from arabinose and mannose.  
     
     
         39 . A process as claimed in  claim 1 , wherein said galactose is D-galactose.  
     
     
         40 . A process as claimed in  claim 23  or  37 , wherein said xylose is D-xylose, said arabinose is L-arabinose, said mannose is D-mannose and said rhamnose is L-rhamnose.  
     
     
         41 . Crystalline plant-based D-galactose product obtained in accordance with  claim 1 .  
     
     
         42 . Crystalline plant-based. non-animal derived D-galactose having a melting point in the range of 163 to 169° C. and a purity of more than 90% on DS.  
     
     
         43 . Crystalline D-galactose as claimed in  claim 42 , which is derived from plant-based biomass containing galactose and one or more further sugars selected from xylose, arabinose, mannose and rhamnose.  
     
     
         44 . Crystalline D-galactose as claimed in  claim 43 , which is derived from plant-based biomass containing galactose and one or more further sugars selected from arabinose and mannose.  
     
     
         45 . Crystalline D-galactose as claimed in  claim 42  derived from hemicellulose-containing material.  
     
     
         46 . Crystalline D-galactose as claimed in  claim 45  derived from wood.  
     
     
         47 . Crystalline D-galactose as claimed in  claim 46  derived from softwood or hardwood.  
     
     
         48 . Crystalline D-galactose as claimed in  claim 42  having a purity of more than 95% on DS.  
     
     
         49 . Crystalline D-galactose as claimed in  claim 48  having a purity of more than 98% on DS.  
     
     
         50 . Crystalline D-galactose as claimed in  claim 49  having a purity of more than 99.5% on DS.  
     
     
         51 . Crystalline non-animal derived D-galactose, which has an impurity profile comprising at least one sugar selected from D-xylose, L-arabinose, D-mannose and L-rhamnose.  
     
     
         52 . Crystalline D-galactose as claimed in  claim 51 , wherein the impurity profile comprises at least one of said sugars in an amount of 0.03% on DS or more.  
     
     
         53 . Crystalline D-galactose as claimed in  claim 52 , wherein the impurity profile comprises L-arabinose in an amount of 0.03% on DS or more.  
     
     
         54 . Crystalline D-galactose as claimed in  claim 52 , wherein the impurity profile comprises at D-mannose in an amount of 0.03% on DS or more.  
     
     
         55 . Crystalline D-galactose as claimed in  claim 51 , wherein the impurity profile comprises at least one of said sugars selected from D-xylose, L-arabinose, D-mannose and L-rhamnose in an amount of 0.10% on DS or more.  
     
     
         56 . Crystalline non-animal derived D-galactose, which has an impurity profile comprising D-glucose in an amount of less than 0.50% on DS.  
     
     
         57 . Crystalline D-galactose as claimed in  claim 56 , wherein the impurity profile comprises D-glucose in an amount of less than 0.30% on DS.  
     
     
         58 . Crystalline non-animal derived D-galactose, which has an impurity profile comprising lactose in an amount of less than 0.10% on DS.  
     
     
         59 . Crystalline D-galactose as claimed in  claim 58 , wherein the impurity profile comprises lactose in an amount of less than 0.03% on DS.  
     
     
         60 . Crystalline non-animal derived D-galactose, which has an impurity profile comprising D-glucose in an amount of less than 0.50% on DS, lactose in an amount of less than 0.10% on DS and at least one further sugar selected from D-xylose, L-arabinose, D-mannose and L-rhamnose.  
     
     
         61 . Crystalline D-galactose as claimed in  claim 60 , wherein the impurity profile comprises at least one of said sugars selected from D-xylose, L-arabinose, D-mannose and L-rhamnose in an amount of 0.03% on DS or more.  
     
     
         62 . Crystalline D-galactose as claimed in  claim 60 , wherein the impurity profile comprises L-arabinose in an amount of 0.03% on DS or more.  
     
     
         63 . Crystalline D-galactose as claimed in  claim 60 , wherein the impurity profile comprises D-mannose in an amount of 0.03% on DS or more.  
     
     
         64 . Crystalline D-galactose as claimed in  claim 60 , wherein the impurity profile comprises glucose in an amount of less than 0.30%.  
     
     
         65 . Crystalline D-galactose as claimed in  claim 60 , wherein the impurity profile comprises lactose in an amount of less than 0.03%.  
     
     
         66 . Crystalline D-galactose as claimed in any one of claims  51 ,  56 ,  58  and  60 , which is plant-based D-galactose.  
     
     
         67 . Crystalline D-galactose as claimed in  claim 66 , which is derived from plant-based biomass.  
     
     
         68 . Crystalline D-galactose as claimed in  claim 66 , which is derived from a plant-based hemicellulose hydrolysate.  
     
     
         69 . Crystalline D-galactose as claimed in  claim 66 , which is derived from a plant-based hemicellulose extract.  
     
     
         70 . Crystalline D-galactose as claimed in  claim 66 , which is derived from wood.  
     
     
         71 . Crystalline D-galactose as claimed in  claim 65 , wherein the wood is selected from softwood and hardwood.  
     
     
         72 . Crystalline D-galactose as claimed in any one of claims  51 ,  56 ,  58  and  60 , which has a melting point in the range of 163 to 169° C.  
     
     
         73 . Pharmaceutical intermediate comprising crystalline D-galactose as claimed in any one of claims  41 ,  42 ,  51 ,  56 ,  58  and  60  for the preparation of pharmaceutically active ingredients.  
     
     
         74 . Pharmaceutical comprising crystalline D-galactose as claimed in any one of claims  41 ,  42 ,  51 ,  56 ,  58  and  60 .  
     
     
         75 . Pharmaceutical for intravenous solutions, comprising crystalline D-galactose as claimed in any one of claims  41 ,  42 ,  51 ,  56 ,  58  and  60 .  
     
     
         76 . Foodstuff comprising crystalline D-galactose as claimed in any one of claims  41 ,  42 ,  51 ,  56 ,  58  and  60 .  
     
     
         77 . Foodstuff as claimed in  claim 76 , which is selected from sports drinks.  
     
     
         78 . Cell culture medium comprising crystalline D-galactose as claimed in any one of claims  41 ,  42 ,  51 ,  56 ,  58  and  60 .  
     
     
         79 . Crystalline galactose intermediate product having a purity of more than 70% galactose on DS and including further sugars selected from xylose, arabinose, rhamnose and mannose in an amount of 2 to 10% on DS.