PROCESS TO PREPARE LEVULINIC ACID
The invention describes processes to prepare levulinic acid, formic acid and/or hydroxymethyl furfural from various biomass materials.
1 . A method to prepare levulinic acid comprising the steps:
heating a first mixture comprising water and sulfuric acid to about 80 to about 160° C. to form a solution;
adding a second mixture of water and a sugar selected from glucose and sucrose to the heated solution over a first period of time to form a liquid reaction mixture in a reactor, wherein the liquid reaction mixture comprises between 20% and 60% sulfuric acid; and
recovering levulinic acid.
2 . The method of claim 1 , wherein the first period of time is between 10 and 300 minutes.
3 . The method of claim 1 , wherein the first period of time is between 20 and 240 minutes.
4 . The method of claim 1 , wherein the first period of time is between 30 and 180 minutes.
5 . The method of claim 1 , wherein the first period of time is between 60 and 180 minutes.
6 . The method of claim 1 , wherein the first period of time is between 60 and 120 minutes.
7 . The method of claim 1 , further comprising the step of heating the reaction mixture for a reaction period at a first reaction temperature after all of the second mixture has been added to the reactor.
8 . The method of claim 7 , wherein the reaction period is between 10 and 300 minutes.
9 . The method of claim 7 , wherein the reaction period is between 20 and 240 minutes.
10 . The method of claim 7 , wherein the reaction period is between 30 and 180 minutes.
11 . The method of claim 7 , wherein the reaction period is between 60 and 180 minutes.
12 . The method of claim 7 , wherein the reaction period is between 60 and 120 minutes.
13 . The method of claim 7 , wherein the first reaction temperature is between approximately 100 to about 180° C.
14 . The method of claim 13 , wherein the first reaction temperature is between approximately 100 to about 160° C.
15 . The method of claim 13 , wherein the first reaction temperature is between approximately 100 to about 140° C.
16 . The method of claim 13 , wherein the first reaction temperature is between approximately 120 to about 140° C.
17 . The method of claim 16 , further comprising the steps:
subjecting the reaction mixture to an extraction solvent to extract levulinic acid into an extract phase;
removing the extract phase from the reaction mixture; and
recovering the levulinic acid from the extract phase.
18 . The method of claim 17 , wherein the extraction solvent is a phenol.
19 . The method of claim 18 , wherein the phenol is a halogenated phenol.
20 . The method of claim 18 , wherein the phenol is an alkyl phenol.
21 . The method of claim 20 , wherein the alkyl phenol is xylenol.
22 . The method of claim 20 , wherein the alkyl phenol is a mixture of xylenol isomers.
23 . The method of claim 17 , wherein recovering levulinic acid from the extract phase comprises distillation or crystallization.
24 . The method of claim 17 , wherein recovering levulinic acid from the extract phase comprises esterification with an alkanol to create a levulinic ester, followed by distillation of the levulinic ester.
25 . The method of claim 17 , further comprising recovering formic acid from the extract phase.
26 . The method of claim 25 , wherein recovering formic acid from the extract phase comprises distillation or crystallization.
27 . The method of claim 25 , wherein recovering formic acid from the extract phase comprises esterification with an alkanol to create a formic ester, followed by distillation of the formic ester.
28 . The method of claim 1 , further comprising the steps:
filtering solids from the reaction mixture, optionally after cooling;
adding a water immiscible liquid to the reaction mixture so that the reaction mixture forms first and second layers, wherein greater than 90% of the sulfuric acid is in the first layer and greater than 90% of the water immiscible liquid is in the second layer;
recovering levulinic acid and optionally formic acid from the second layer; and
recycling the first layer back to the reactor.
29 . The method of claim 28 , wherein the water immiscible liquid is a phenol.
30 . The method of claim 29 , wherein the phenol is a halogenated phenol.
31 . The method of claim 29 , wherein the phenol is an alkyl phenol.
32 . The method of claim 31 , wherein the alkyl phenol is xylenol.
33 . The method of claim 28 , wherein the alkyl phenol is a mixture of xylenol isomers.
34 . The method of claim 28 , wherein recovering levulinic acid or formic acid from the second layer comprises distillation or crystallization.
35 . The method of claim 28 , wherein recovering levulinic acid from the second layer comprises esterification with an alkanol to create a levulinic ester, followed by distillation of the levulinic ester.
36 . The method of claim 28 , wherein recovering formic acid from the second layer comprises esterification with an alkanol to create a formic ester, followed by distillation of the formic ester.
37 . The method of claim 1 , wherein the levulinic acid is recovered in a yield greater than 40% mol.
38 . The method of claim 1 , wherein the levulinic acid is recovered in a yield greater than 45% mol.
39 . The method of claim 1 , wherein the levulinic acid is recovered in a yield greater than 50% mol.
40 . The method of claim 1 , wherein the second mixture is water and glucose.
41 . The method of claim 40 , wherein the greater than 75% of the glucose is converted.
42 . The method of claim 40 , wherein the greater than 80% of the glucose is converted.
43 . The method of any of claim 40 , wherein the greater than 85% of the glucose is converted.
44 . The method of claim 1 , wherein the second mixture is water and sucrose.
45 . The method of claim 1 , wherein the reactor is a continuous addition batch reactor.
46 . The method of claim 1 , wherein the reactor is a CSTR reactor.
47 . The method of claim 44 , wherein the reactor is a multi stage reactor comprising at least a first reactor and a second reactor.
48 . A method to prepare levulinic acid comprising the steps:
heating a first mixture comprising water and sulfuric acid to about 80 to about 160° C. to form a solution;
adding a second mixture of sugar and water to the heated solution over a first period of time to form a liquid reaction mixture in a first reactor, wherein the liquid reaction mixture comprises between 20% and 60% sulfuric acid;
heating the reaction mixture for a first reaction period at a first reaction temperature after all of the second mixture has been added to the first reactor;
feeding the liquid reaction mixture to a second reactor;
heating the reaction mixture for a second reaction period at a second reaction temperature after all of the second mixture has been added to the second reactor; and
recovering levulinic acid.
49 . The method of claim 48 , further comprising the step of recirculating the reaction mixture from the second reactor to the first reactor.
50 . The method of claim 48 , further comprising the step of adding a third mixture comprising a solution of sugar and water to the second reactor.
51 . The method of claim 50 , wherein the addition of the third mixture to the second reactor is simultaneous with the addition of the second mixture to the first reactor.
52 . The method of claim 48 , wherein the sugar is selected from the group consisting of fructose, glucose, sucrose and mixtures thereof.
53 . The method of claim 52 , wherein the sugar is sucrose.
54 . The method of claim 48 , wherein the first period of time is between 10 and 300 minutes.
55 . The method of claim 48 , wherein the first period of time is between 20 and 240 minutes.
56 . The method of claim 48 , wherein the first period of time is between 30 and 180 minutes.
57 . The method of claim 48 , wherein the first period of time is between 60 and 180 minutes.
58 . The method of claim 48 , wherein the first period of time is between 60 and 120 minutes.
59 . The method of claim 48 , wherein the first reaction period is between 10 and 300 minutes.
60 . The method of claim 48 , wherein the first reaction period is between 20 and 240 minutes.
61 . The method of claim 48 , wherein the first reaction period is between 30 and 180 minutes.
62 . The method of claim 48 , wherein the first reaction period is between 60 and 180 minutes.
63 . The method of claim 48 , wherein the first reaction period is between 60 and 120 minutes.
64 . The method of claim 48 , wherein the first reaction temperature is between approximately 100 to about 180° C.
65 . The method of claim 48 , wherein the first reaction temperature is between approximately 90 to about 130° C.
66 . The method of claim 48 , wherein the first reaction temperature is between approximately 100 to about 130° C.
67 . The method of claim 48 , wherein the first reaction temperature is between approximately 110 to about 120° C.
68 . The method of claim 48 , wherein the second reaction period is between 10 and 300 minutes.
69 . The method of claim 48 , wherein the second reaction period is between 20 and 240 minutes.
70 . The method of claim 48 , wherein the second reaction period is between 30 and 180 minutes.
71 . The method of claim 48 , wherein the second reaction period is between 60 and 180 minutes.
72 . The method of claim 48 , wherein the first reaction period is between 60 and 120 minutes.
73 . The method of claim 48 , wherein the second reaction temperature is between approximately 120 to about 180° C.
74 . The method of any of claim 48 , wherein the second reaction temperature is between approximately 120 to about 160° C.
75 . The method of claim 48 , wherein the second reaction temperature is between approximately 130 to about 150° C.
76 . The method of claim 48 , wherein the second reaction temperature is between approximately 130 to about 140° C.
77 . The method of claim 48 , further comprising the steps:
subjecting the reaction mixture to an extract solvent to extract levulinic acid into an extract phase;
removing the extract phase from the reaction mixture; and
recovering the levulinic acid from the extract phase.
78 . The method of claim 77 , wherein the extract solvent is a phenol.
79 . The method of claim 78 , wherein the phenol is a halogenated phenol.
80 . The method of claim 78 , wherein the phenol is an alkyl phenol.
81 . The method of claim 80 , wherein the alkyl phenol is xylenol.
82 . The method of claim 80 , wherein the alkyl phenol is a mixture of xylenol isomers.
83 . The method of claim 77 , wherein recovering levulinic acid from the extract phase comprises distillation or crystallization.
84 . The method of claim 77 , wherein recovering levulinic acid from the extract phase comprises esterification with an alkanol to create a levulinic ester, followed by distillation of the levulinic ester.
85 . The method of claim 77 , further comprising recovering formic acid from the extract phase.
86 . The method of claim 85 , wherein recovering formic acid from the extract phase comprises distillation or crystallization.
87 . The method of claim 85 , wherein recovering formic acid from the extract phase comprises esterification with an alkanol to create a formic ester, followed by distillation of the formic ester.
88 . The method of any of claims 48 through 87 , further comprising the steps:
filtering solids from the reaction mixture, optionally after cooling;
adding a water immiscible liquid to the reaction mixture so that the reaction mixture forms first and second layers, wherein greater than 90% of the sulfuric acid is in the first layer and greater than 90% of the water immiscible liquid is in the second layer;
recovering levulinic acid and optionally formic acid from the second layer; and
recycling the first layer back to the first or second reactor.
89 . The method of claim 88 , wherein the water immiscible liquid is a phenol.
90 . The method of claim 89 , wherein the phenol is a halogenated phenol.
91 . The method of claim 89 , wherein the phenol is an alkyl phenol.
92 . The method of claim 91 , wherein the alkyl phenol is xylenol.
93 . The method of claim 91 , wherein the alkyl phenol is a mixture of xylenol isomers.
94 . The method of claim 88 , wherein recovering levulinic acid or formic acid from the second layer comprises distillation or crystallization.
95 . The method of claim 88 , wherein recovering levulinic acid from the second layer comprises esterification with an alkanol to create a levulinic ester, followed by distillation of the levulinic ester.
96 . The method of claim 88 , wherein recovering formic acid from the second layer comprises esterification with an alkanol to create a formic ester, followed by distillation of the formic ester.