Processes for Extraction of Sugar From Sugar-Bearing Plant Material

Abstract

The invention provides processes for the extraction of sugar from sugar-bearing plant material such as sugar cane. Accordingly, in one aspect of the invention, a process for extracting sugar from sugar-bearing plant material comprises contacting the sugar-bearing plant material with an extractant solution comprising water and a surfactant; and separating the extractant solution from the sugar-bearing plant material. One example of a suitable surfactant is a poly(alkylene oxide) polymer such as a poly(propylene oxide) polymer, a poly(ethylene oxide) polymer, or a poly(propylene oxide)/(ethylene oxide) copolymer.

1 . A process for extracting sugar from sugar-bearing plant material, the process comprising:
 contacting the sugar-bearing plant material with an extractant solution comprising water and a surfactant; and   separating the extractant solution from the sugar-bearing plant material.   
     
     
         2 . The process of  claim 1 , wherein the extractant solution consists essentially of water, surfactant, optionally a solvent, and optionally sugar-bearing plant material juice. 
     
     
         3 . The process of  claim 1 , wherein the sugar-bearing plant material is sugar cane material. 
     
     
         4 . The process of  claim 3 , wherein the sugar cane material is sugar cane bagasse. 
     
     
         5 . The process of  claim 1 , further comprising grinding, milling, chopping, pulping, shredding or macerating the sugar-bearing plant material before contacting it with the extractant solution. 
     
     
         6 . The process of  claim 1 , wherein the sugar-bearing plant material is ground, milled, chopped, pulped, shredded or macerated while it is being contacted with the extractant solution. 
     
     
         7 . The process of  claim 1 , further comprising grinding, milling, chopping, pulping, shredding or macerating the sugar-bearing plant material before contacting it with the extractant solution, and wherein the sugar-bearing plant material is ground, milled, chopped, pulped, shredded or macerated while it is being contacted with the extractant solution. 
     
     
         8 . The process of  claim 1 , wherein the surfactant is present in the extractant solution at a concentration in the range of about 0.2 ppm to about 1000 ppm based on the mass of the extractant solution. 
     
     
         9 . The process of  claim 1 , wherein the surfactant is present in the extractant solution at a concentration in the range of about 0.5 ppm to about 500 ppm based on the mass of the extractant solution. 
     
     
         10 . The process of  claim 1 , wherein the surfactant is a nonionic surfactant. 
     
     
         11 . The process of  claim 1 , wherein the surfactant is a poly(alkylene oxide) polymer. 
     
     
         12 . The process of  claim 11 , wherein the surfactant is a poly(propylene oxide) polymer, a poly(ethylene oxide) polymer, or a poly(propylene oxide)/(ethylene oxide) copolymer. 
     
     
         13 . The process of  claim 11  wherein the surfactant has a number average molecular weight of at least about 1500 g/mol. 
     
     
         14 . The process of  claim 11  wherein the surfactant has a number average molecular weight of at least about 3000 g/mol. 
     
     
         15 . The process of  claim 11  wherein the surfactant has a functionality of OH capping groups of at least about 1.5. 
     
     
         16 . The process of  claim 11 , wherein the surfactant is of the formula (I): 
       
         
           
           
               
               
           
         
       
       in which each of x and y are greater than zero. 
     
     
         17 . The process of  claim 11 , wherein the surfactant has ethylene oxide units in the range of about 5 wt % to about 85 wt %. 
     
     
         18 . The process of  claim 11 , wherein the surfactant has ethylene oxide units in the range of about 10 wt % to about 40 wt %. 
     
     
         19 . The process of  claim 11 , wherein the surfactant is an α-Hydro-omega-hydroxy-poly(oxyethylene)/poly(oxypropylene) (minimum 15 moles/poly(oxyethylene)) block copolymer, having a minimum average molecular weight of 1900 g/mol and a minimum cloud point of 9° C.-12° C. in 10 percent aqueous solution. 
     
     
         20 . A process for making a sugar product from a sugar-bearing plant material, the process comprising:
 extracting sugar from the sugar-bearing plant material as described in  claim 1  to form a sugar-bearing extractant solution; and   processing and refining the extractant solution to form the sugar product.   
     
     
         21 . A sugar product made by the process of  claim 20 . 
     
     
         22 . A process for making ethanol from a sugar-bearing plant material, the process comprising:
 extracting sugar from the sugar-bearing plant material as described in  claim 1  to form a sugar-bearing extractant solution;   processing and fermenting the sugar-bearing extractant solution to form an aqueous ethanol solution; and   isolating the ethanol from the aqueous ethanol solution.