Process to prepare levulinic acid

Abstract

The invention describes processes to prepare levulinic acid, formic acid and/or hydroxymethyl furfural from various biomass materials.

1 . A process to prepare levulinic acid comprising the steps:
 a) heating an aqueous solution of a mineral acid to about 60° C. to about 110° C. in a reactor; and   b) adding high fructose corn syrup, a mixture of at least two different sugars, sucrose, an aqueous mixture comprising fructose, an aqueous mixture comprising fructose and glucose, an aqueous mixture comprising hydroxymethylfurfural, an aqueous solution of fructose and hydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixture of maltose, an aqueous mixture of inulin, an aqueous mixture of polysaccharides, or mixtures thereof to the heated aqueous acid in the reactor over a period of time to form a reaction mixture including levulinic acid.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The process of  claim 1 , wherein the mineral acid percentage by weight is from about 20 to about 80 percent of the reaction mixture. 
     
     
         5 . (canceled) 
     
     
         6 . The process of  claim 1 , wherein the high fructose corn syrup contains between about 1 and about 99 weight percent of fructose and from about 99 to about 1 weight percent glucose with the remainder water, wherein the sugar content is between about 1 and about 99% by weight. 
     
     
         7 . The process of  claim 6 , wherein the high fructose corn syrup is added over a period of from about 0.1 to about 40 hours. 
     
     
         8 - 28 . (canceled) 
     
     
         29 . The process of  claim 1 , further comprising the step of heating the mixture to a temperature of from about 25° C. to about 160° C. to reduce any residual glucose levels. 
     
     
         30 - 35 . (canceled) 
     
     
         36 . The process of  claim 1 , further comprising filtering out solids from the mixture including levulinic acid to provide a first filtrate. 
     
     
         37 - 38 . (canceled) 
     
     
         39 . The process of  claim 1 , further comprising combining the mixture comprising levulinic acid with an extraction solvent to create an extraction phase and a raffinate phase. 
     
     
         40 - 41 . (canceled) 
     
     
         42 . The process of  claim 39 , wherein the extraction solvent is selected from the group consisting of methyl iosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone, cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol, n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol, 1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol, nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol, ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol, o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25 m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethyl phenol and mixtures thereof. 
     
     
         43 . The process of  claim 42 , further comprising recycling the raffinate phase to the reactor. 
     
     
         44 - 45 . (canceled) 
     
     
         46 . The process of claim  45 , further comprising adding high fructose corn syrup, a mixture of at least two different sugars, sucrose, an aqueous mixture comprising fructose, an aqueous mixture comprising fructose and glucose, an aqueous mixture comprising hydroxymethylfurfural, an aqueous solution of fructose and hydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixture of maltose, an aqueous mixture of inulin, an aqueous mixture of polysaccharides, or mixtures thereof to the raffinate phase in the reactor over a period of time to form a mixture including levulinic acid. 
     
     
         47 . The process of  claim 46 , further comprising separating levulinic acid, formic acid, or both from the extraction solvent. 
     
     
         48 . (canceled) 
     
     
         49 . The process of  claim 1 , wherein the reactor is a batch reactor. 
     
     
         50 . (canceled) 
     
     
         51 . A process to prepare levulinic acid comprising the steps:
 a) heating an aqueous solution of a mineral acid to about 60° C. to about 110° C.;   b) adding a first aqueous mixture comprising fructose and glucose to the heated aqueous mineral acid over a period of time to form a mixture including levulinic acid;   c) optionally cooling the mixture to room temperature; and   d) heating the mixture, optionally in a sealed reactor, from about 25° C. to about 160° C. under pressure of 75 psi or below;   e) optionally cooling the heated mixture of step d) to room temperature; and   f) filtering the mixture to provide a first filtrate and solids.   
     
     
         52 - 54 . (canceled) 
     
     
         55 . The process of  claim 51 , wherein the final filtrate is treated with a water immiscible solvent to form a water immiscible layer and a raffinate. 
     
     
         56 . The process of  claim 55 , wherein the water immiscible layer is separated from the aqueous layer and subjected to distillation. 
     
     
         57 - 66 . (canceled) 
     
     
         67 . A process to prepare levulinic acid comprising the steps:
 a) heating an aqueous solution of a mineral acid to about 60° C. to about 110° C.;   b) adding high fructose corn syrup, a mixture of at least two different sugars, sucrose, an aqueous mixture comprising fructose, an aqueous mixture comprising fructose and glucose, an aqueous mixture comprising hydroxymethylfurfural, an aqueous solution of fructose and hydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixture of maltose, an aqueous mixture of inulin, an aqueous mixture of polysaccharides, or mixtures thereof to the heated aqueous mineral acid over a period of time to form a reaction mixture in a reactor to form a mixture including levulinic acid and solids;   c) filtering the solids from the mixture, optionally after cooling;   d) adding a water immiscible liquid to the mixture so that the mixture forms first and second layers, wherein greater than 90% of the mineral acid is in the first layer and greater than 90% of the water immiscible liquid is in the second layer;   e) recovering levulinic acid and optionally formic acid from the second layer; and   f) recycling the first layer back to the reactor.   
     
     
         68 - 72 . (canceled) 
     
     
         73 . The process of  claim 67 , wherein the mineral acid percentage by weight is from about 20 to about 80 percent of the reaction mixture. 
     
     
         74 . (canceled) 
     
     
         75 . The process of  claim 67 , wherein the mineral acid percentage by weight is from about 40 to about 80 percent of the reaction mixture. 
     
     
         76 . (canceled) 
     
     
         77 . The process of  claim 67 , wherein the water immiscible liquid is selected from the group consisting of methyl iosamyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone, cyclohexanone, isophorone, neopentyl alcohol, isoamyl alcohol, n-hexanol, n-heptanol, 2-ethyl hexanol, n-octanol, 1-nonanol, 1-undecanol, phenol, 4-methoxyphenol, guaiacol, 2-sec butyl phenol, nonyl phenol, methylene chloride, methyl isobutyl carbinol, anisol, ethylene glycol di-n-butyl ether, castor oil, m-cresol, p-cresol, o-cresol, cresol mixtures, 60/40 m-cresol/p-cresol, 75/25 m-cresol/p-cresol, diethyl carbonate, methyl salicylate, 2,4-dimethyl phenol and mixtures thereof. 
     
     
         78 . The process of  claim 77 , wherein the high fructose corn syrup, a mixture of at least two different sugars, sucrose, an aqueous mixture comprising fructose, an aqueous mixture comprising fructose and glucose, an aqueous mixture comprising hydroxymethylfurfural, an aqueous solution of fructose and hydroxymethylfurfural, an aqueous mixture of glucose, an aqueous mixture of maltose, an aqueous mixture of inulin, an aqueous mixture of polysaccharides, or mixtures added over a period of from about 0.1 to about 40 hours. 
     
     
         79 - 99 . (canceled)