WO2010030617A1

WO2010030617A1 - A method of recovering levulinic acid

Info

Publication number: WO2010030617A1
Application number: PCT/US2009/056296
Authority: WO
Inventors: Frank Seibert
Original assignee: Meadwestvaco Corp
Current assignee: WestRock MWV LLC
Priority date: 2008-09-09
Filing date: 2009-09-09
Publication date: 2010-03-18
Anticipated expiration: 2011-03-09

Abstract

A method of recovering levulinic acid from an aqueous mixture containing levulinic acid, formic acid and furfural, is disclosed. The aqueous mixture may be obtained by acidic hydrolysis of various raw materials, including low-cost natural products such as biomass. Furfural, one of the products in the aqueous mixture, is used as an extracting solvent. The mixture is extracted into an aqueous-rich phase containing some formic acid and furfural; and a furfural-rich phase containing some water, levulinic acid, formic acid and furfural. The levulinic acid may be isolated from the furfural-rich phase through distillation. The furfural-rich phase may be subjected to a series of distillation process to isolate formic acid from the furfural solvent. A fraction of the furfural recovered from the distillation may be recycled and reused as an extracting solvent; the remaining fraction may be sold as product.

Description

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE Acting as International Receiving Office (RO/US)

International Patent Application For

A METHOD OF RECOVERING LEVULINIC ACID

This non-provisional application relies on the filing date of provisional U.S. Application Serial No. 61/095370 filed on September 9, 2008, having been filed within twelve (12) months thereof, which is incorporated herein by reference, and priority thereto is claimed under 35 USC § 1.19(e).

BACKGROUND OF THE DISCLOSURE [0001] Levulinic acid has been recognized in various applications. It is a starting material for the production of a variety of industrial and pharmaceutical compounds such as resins, plasticizers, herbicides, and specialty chemicals. However, its commercial significance has been limited due in part to its high production cost. Several methods have been reported for preparing levulinic acids. However, these synthetic methods often require high-cost raw materials and provide low synthetic yields.

[0002] Research effort has been spent developing an economically viable and environmentally safe process for producing levulinic acid, particularly from an inexpensive and renewable feedstock such as biomass.

[0003] U.S. Patent No. 5,608,105 discloses a process of producing levulinic acid and formic acid from carbohydrate-containing raw materials using two reactors in which the temperature, reaction time, and acid content are closely controlled. The raw materials are supplied to a first reactor and hydrolyzed at between 210° C-230° C in the presence of mineral acid to produce hydroxymethylfurfural along with other reaction intermediates, which are then conveyed into a second reactor. The resulting hydroxymethylfurfural is hydrolyzed further at 195° C-215° C in the presence of mineral acid in the second reactor to produce levulinic acid, furfural, formic acid, and other by-products. To facilitate the separation of levulinic acid from the product mixture, the process conditions of the second reactor are adjusted such that furfural and formic acid are vaporized and externally condensed, whereas the levulinic acid is concentrated at the bottom of the reactor. Once the concentration of the levulinic acid is sufficiently high, a stream containing levulinic acid is removed from the steady-state reaction mix in the reactor. Since the conditions in the second reactor must facilitate both the hydrolysis reaction and the separation of levulinic acid from other by- products, the optimum condition ranges could be limited and high level of operational preciseness is required for each manufacturing production.

[0004] U.S. Patent No. 5,859,263 describes a process for producing levulinic acid by extruding a mixture of starch, water and mineral acid in a screw extruder at a temperature of 80°C-150°C. Then, the levulinic acid is isolated from the reaction product mixture by a series of steps: filtration, steam distillation, condensation, and finally centrifugation.

[0005] U.S. Patent No. 5,892,107 discloses a method of recovering levulinic acid from an aqueous acidic hydrolysis reaction mixture of biomass using chromatography technique. This recovering process demands multiple separation steps and chromatographic columns in order to achieve an acceptable recovery yield.

[0006] U.S. Patent No. 7,153,996 reports the use of olefin to facilitate the separation of levulinic acid from other reaction products of the acidic hydrolysis of biomass. First, the biomass is acidic hydrolyzed to provide a mixture of levulinic acid, formic acid and furfural. Then, the aqueous product mixture is reacted with at least one olefin, optionally in the presence of a second acid catalyst, to produce an aqueous phase and an organic phase containing levulinic esters and formic esters. Finally, the organic phase is separated from the aqueous phase. In this process, however, the levulinic acid is never isolated from other by- products. Rather, the levulinic acid is converted into levulinic ester and applied for the selected end-used applications as a mixture with formate ester.

[0007] U.S. Patent No. 7,378,549 teaches a reactive extraction of levulinic acid by contacting an aqueous acidic hydrolysis reaction mixture with liquid esterifying alcohol at esterification conditions in the presence of a catalyst. The liquid esterifying alcohol is substantially water-immiscible and comprises at least four carbon atoms. The extraction conditions and the amount of esterifying alcohol are controlled such that the levulinic acid in the aqueous mixture reacts with the esterifying alcohol solvent to provide levulinate ester, which is then extracted from the aqueous mixture. To obtain the levulinic acid, the isolated levulinic ester must be subjected to yet another acidic hydrolysis reaction to convert the levulinic ester back to the desired levulinic acid.

[0008] U.S. Patent No. 7,520,905 discloses a method of producing biodiesel fuel via an acidic hydrolysis of biomass using sulfuric acid as catalyst. The acidic hydrolysis of biomass provides sugars, which is then converted into dehydrated sugars, such as furfural and hydroxymethylfurfural (HMF). Sulfuric acid serves as a catalyst for HMF heterocyclic ring opening to form levulinic acid, resulting in a hydrolysate containing furfural, formic acid, and levulinic acid. Biodiesel fuel oil, such as soybean oil and canola oil, is used to extract furfural and levulinic acid from the hydrolysis product mixture. The extracted hydrolysate is subjected to a water permeable member to reduce the water content, and subsequently recycled for further hydrolysis of biomass. The sulfuric acid is recovered and reused for the hydrolysis operation. In this disclosed method, the formic acid, thus formed, is unstable and decomposes within hot sulfuric acid to yield water and carbon monoxide. Therefore, a valuable formic acid is lost in the process. Additionally, the carbon monoxide resulted from the decomposition of formic acid leads to environmental concerns of carbon footprints. The product of the disclosed process is biodiesel oil containing a mixture of furfural and levulinic acid as additives; therefore, the disclosed process does not isolate levulinic acid from furfural.

[0009] Accordingly, there is a still need for a process of recovering levulinic acid from the acidic hydrolysis reaction mixture that is simple to operate and economical for commercial scale production.

SUMMARY OF THE DISCLOSURE [0010] A method of recovering levulinic acid from an aqueous mixture containing levulinic acid, formic acid and furfural, is disclosed that is simple to operate and economical for commercial scale production. The mixture may be obtained by acidic hydrolysis of various raw materials, including low-cost natural products such as biomass. Furfural, one of the products in the aqueous mixture, is used as an extracting solvent. The mixture is separated into an aqueous-rich phase containing some formic acid and furfural; and a furfural-rich phase containing some water, levulinic acid, formic acid and furfural. The levulinic acid may be isolated from the furfural-rich phase through distillation. The furfural- rich phase may be subjected to a series of distillation process to isolate formic acid from the furfural solvent. A fraction of the furfural recovered from the distillation may be recycled and reused as an extracting solvent; the remaining fraction may be sold as product.

BRIEF DESCRIPTION OF THE DRAWINGS [0011 ] FIG. 1 is a schematic diagram of a known process for isolating levulinic acid from other reaction products of the acidic hydrolysis of biomass;

[0012] FIG. 2 is a schematic diagram of one embodiment of the disclosed process for isolating levulinic acid from an aqueous mixture comprising furfural, formic acid, and levulinic acid; [0013] FIG. 3 is a graph showing a comparative equilibrium distribution of levulinic acid and formic acid in two different solvents: furfural and water;

[0014] FIG. 4 is a graph showing the comparative partitioning of levulinic acid for three different solvents: furfural, methyl isobutyl ketone (MIBK), and isopropyl acetate (IPA); [0015] FIG. 5 is a schematic diagram of one embodiment of the disclosed process for isolating levulinic acid from an aqueous mixture comprising furfural, formic acid, and levulinic acid;

[0016] FIG. 6 is a schematic diagram showing a stream analysis for the extraction vessel being fed with furfural extracting solvent and the aqueous condensate comprising furfural, and formic acid;

[0017] FIG. 7 is a schematic diagram showing a stream analysis for the extraction vessel being fed with furfural extracting solvent and the hydrolysate comprising formic acid, furfural, and levulinic acid;

[0018] FIG. 8 is a schematic diagram showing a stream analysis for the distillation vessel of a mixture containing furfural, formic acid and levulinic acid;

[0019] FIG. 9 is a schematic diagram showing a stream analysis for the distillation vessel of a mixture containing furfural, formic acid and water; and

[0020] FIG. 10 is a schematic diagram showing a stream analysis for the distillation vessel of a mixture containing furfural and formic acid and water.

DESCRIPTION OF THE DISCLOSURE

[0021] The present disclosures now will be described more fully hereinafter, but not all embodiments of the disclosure are necessarily shown. While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof.

[0022] FIG. 1 shows a known process of extracting levulinic acid from an aqueous- rich feed using a conventional solvent such as methyl isobutyl ketone (MIK) or isopropyl acetate (IPA). In this process, four distillation columns are used to separate five components: crude levulinic acid, conventional solvent, water, furfural and formic acid. The crude levulinic acid is purified with another distillation column to remove non-volatile impurities. A steam stripper must be utilized to recover the conventional solvent and minimize solvent loss to the aqueous raffmate leaving the extraction. First, the biomass is hydrolyzed in a presence of a strong acid in the mixer, providing an aqueous acidic hydrolysis mixture comprising levulinic acid along with formic acid and furfural by-products. The resulting aqueous acidic hydrolysis mixture is then flashed to separate out an aqueous condensate (1), comprising formic acid and furfural by-products. The other portion of the aqueous acidic hydrolysis mixture is further hydrolyzed and then concentrated to provide hydrolysate containing levulinic acid along with other acidic hydrolysis by-products. The hydrolysate is subjected to filtration prior to an extraction process. The filtered hydrolysate is then fed into an extraction along with a water-immiscible solvent and the condensate (1). The water- immiscible solvents suitable as extracting solvents are low molecular weight ketones, ethers or acetates, such as those containing more than five carbon atoms. The compounds in the extraction vessel are extracted into (i) an organic phase (extract) containing levulinic acid, formic acid, furfural and the extracting water-immiscible solvent; and (ii) an aqueous phase (raffinate) containing acid catalyst and a small amount of the water-immiscible solvent. The resulting aqueous phase is then subjected to a (steam) stripping column, wherein the water- immiscible solvent is isolated from the aqueous solution. The isolated aqueous portion containing the acid is recycled back to mixer and reused in the acid-hydrolysis reaction. The isolated water-immiscible solvent is recycled back to the extraction vessel and reused as the extracting solvent. The organic phase (extract) is distilled to provide a first bottom stream containing crude levulinic acid and a first overhead stream containing some water, formic acid, furfural, and the extracting solvent. The obtained crude levulinic acid is distilled to provide purified levulinic acid. The first overhead stream containing some water, formic acid, furfural and the extracting solvent is then subjected to further distillation to separate the extracting solvent as a second overhead stream from a second bottom stream containing a mixture of formic acid and furfural. The second bottom stream is finally distilled to separate formic acid from furfural, providing a third overhead stream containing formic acid residues and a third bottom stream containing furfural.

[0023] FIG. 2 shows one embodiment of the disclosed method of recovering levulinic acid from an aqueous acidic hydrolysis mixture. This embodiment comprises steps of: (a) acidic hydrolysis of a raw material, such as biomass, to produce an aqueous mixture comprising levulinic acid, formic acid, and furfural; (b) flashing the aqueous mixture to provide a condensate portion (1) comprising water, formic acid and furfural; and a hydrolysate portion comprising formic acid, furfural and levulinic acid;

(c) providing furfural as an extracting solvent;

(d) feeding the condensate (1), the hydrolysate and the furfural solvent into an extraction vessel;

(e) performing liquid-liquid extraction in the extraction vessel to generate an aqueous-rich phase containing soluble furfural; and a furfural-rich phase containing some water, formic acid, levulinic acid and furfural;

(f) subjecting the furfural -rich phase into a first distillation vessel to provide a first overhead stream containing water, formic acid and furfural; and a first bottom stream containing levulinic acid;

(g) optionally, distillating the first bottom stream to provide purified levulinic acid; (h) subjecting the first overhead stream into a second distillation vessel to remove furfural as a bottoms product while water, some furfural and formic acid are recovered as a distillate product;

(i) feeding the second distilled portion into a third distillation vessel to remove water as a light boiling azeotrope with furfural and remove formic acid as a bottoms product.

[0024] The biomass from a refiner may be used as a raw material for the acidic hydrolysis reaction. The biomass is fed into a mixer and hydrolyzed in a presence of an acid catalyst to provide an aqueous acidic hydrolysis mixture comprising levulinic acid, formic acid, and furfural. The mixture may be flashed to separate an aqueous condensate (1), containing formic acid and furfural, from the rest of the mixture. Subsequently, the rest of the mixture is hydrolyzed and, optionally concentrated, to provide a hydrolysate containing levulinic acid, formic acid and furfural. The hydrolysate may be subjected to filtration prior to extraction. Furfural is used as an extracting solvent. The hydrolysate is fed into an extraction vessel along with the condensate (1) and the furfural extracting solvent. The furfural solvent extracts the mixture in a vessel. An aqueous-rich (raffinate) phase containing acid catalyst, some formic acid and furfural leaves the top of the column and is sent to a steam stripper; and a furfural-rich phase containing some water, levulinic acid, formic acid, and furfural leaves the bottom of the vessel. After separation from the aqueous-rich phase, the furfural-rich phase may be distilled in a first distillation vessel to provide a first bottom stream containing crude levulinic acid, and a first overhead stream containing some water, formic acid and furfural. When desired, the first bottom stream may be subjected to further distillation to provide purified levulinic acid.

[0025] The first overhead stream is fed to a second distillation column where furfural is separated as a bottoms product. The second distillate contains some water, some furfural and formic acid and is fed to a third distillation column. Water and furfural are removed as a light boiling azeotrope and formic acid is removed as a bottoms product. In another alternative embodiment, the light boiling water- furfural azeotrope could be removed in the second distillation column and the bottoms of the second distillation column containing furfural and formic acid is fed to the third distillation column. In yet another alternative embodiment, formic acid is distilled as an overhead product and furfural is recovered as a bottoms product. It is to be understood that other alternative processes may be used to isolate furfural and formic acid from the first overhead stream.

[0026] FIG. 3 shows a comparative equilibrium distribution of levulinic acid and formic acid in two different solvent media: furfural and water. FIG. 4 compares the partitioning of levulinic acid in furfural solvent to two conventional solvents: methyl isobutyl ketone (MIBK) and isopropyl acetate (IPA). The greater slope associated with the furfural, compared to the two conventional solvents, demonstrates that furfural has a greater capacity for extraction of levulinic acid. These data indicate that when furfural is used as an extracting solvent, a much lower ratio of solvent to levulinic acid is required. Therefore, upon using furfural as an extracting solvent, fewer numbers and smaller size of extraction and distillation columns may be used. Additionally, a reduction in steam consumption associated with the distillation steps may be achieved. At appropriated extraction conditions, the extraction selectivity of furfural for levulinic acid may be twice of those for the MIBK and IPA solvents. Thus, the required extracting solvent/feed ratio may be reduced by a factor of two. The furfural has superior extraction power, compared to conventional solvents, to pull levulinic acid, formic acid, and of course additional furfural from the aqueous acidic hydrolysis reaction mixture into the organic phase during the extraction process.

Additionally, furfural may be beneficial as an azeotroping solvent in removing water during the recovery of formic acid. As such, the need of azeotroping solvent may be minimized, if not completely eliminated. Drying agent such as molecular sieve may not be required. Moreover, it may not be necessary to recover the furfural from the aqueous raffmate leaving the extraction vessel, thereby eliminating the need for steam stripper to recover furfural from the aqueous stream.

[0027] FIG. 5 shows one embodiment of the disclosed method of recovering levulinic acid from an aqueous acidic hydrolysis mixture. The method comprises steps of: (a) acidic hydrolysis of a raw material, such as biomass, to produce an aqueous mixture comprising levulinic acid, formic acid, and furfural;

(b) flashing the aqueous mixture to provide an aqueous condensate portion (CF-I) comprising formic acid and furfural; and the hydrolysate portion (HYFD-2) comprising formic acid, furfural and levulinic acid; (c) providing furfural as an extracting solvent;

(d) feeding the condensate (CF-I) and the furfural (FS-I) solvent into a first extraction vessel (E-I);

(e) performing liquid-liquid extraction in the first extraction vessel to generate a first aqueous-rich phase (R-I) containing water, some formic acid and furfural; and a first furfural-rich phase (EX-I) containing some water, formic acid and furfural;

(f) feeding the hydrolysate (HYFD-2) and the furfural (FS-2) solvent into a second extraction vessel (E-2);

(g) performing liquid-liquid extraction in the second extraction vessel to generate a second aqueous-rich phase (R-2) containing water, formic acid and furfural; and a second furfural-rich phase (EX -2) containing formic acid, furfural and levulinic acid;

(h) subjecting the second furfural-rich phase (EX-2) into a first distillation vessel (D- 1) to provide a first overhead stream (OVHD-I) containing water, formic acid and furfural; and a first bottom stream (BOT-I) containing levulinic acid; (i) subjecting the first overhead stream (OVHD-I) and the first furfural-rich phase (EX-I) into a second distillation vessel (D-2) to provide a second overhead stream (OVHD-2) containing water and furfural; and a second bottom stream (BOT-2) containing formic acid and furfural; (j) subjecting the second bottom stream (BOT-2) into a third distillation vessel (D-3) to provide a third overhead stream (OVHD-3) containing formic acid; and a third bottom stream (BOT-3) containing furfural.

[0028] The aqueous acidic hydrolysis of low-cost natural products, such as biomass, generates levulinic acid along with by-products including formic acid and furfural. The disclosed method of recovering levulinic acid from such hydrolysis mixture utilizes the furfural by-product as an extracting solvent. The disclosed method requires no additional extracting solvent, thereby eliminating the raw material cost for extracting solvent and the operation cost for additional separation steps required to isolate the desired chemicals from the extracting solvent itself. Additionally, in the disclosed process, it may not be necessary to recover the furfural from the aqueous raffmate leaving the extraction. Therefore a steam stripper may not be required. The disclosed process is much simpler to operate compared to the processes of known art; therefore, a significant reduction in operation cost may be achieved. Moreover, the capital cost may be substantially reduced since, comparing to the processes of known art, the disclosed process requires fewer storage tanks and distillation columns.

[0029] The disclosed process is suitable for recovering levulinic acid for an aqueous acidic hydrolysis reaction mixture of a variety of raw materials. When desired, low-cost natural products such as biomass may be used as the raw material source. Examples of the sources from biomass include, but are not limited to, rice straw materials, woody plant materials, paper materials, cotton materials, lignocellulosic materials, corn stalks, bagasse, sugar-based materials, carbohydrate materials, and mixtures thereof.

EXPERIMENTS

[0030] In order that the disclosure may be more fully understood, the-following examples are provided. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting the present disclosure in any way. [0031 ] Furfural was used as an extracting solvent to isolate levulinic acid and formic acid from an aqueous acidic hydrolysis reaction mixture. The liquid extractions were carried out using a 2.5 cm-diameter Karr reciprocating plate extractor. The extraction was performed at 25° C. The distillation was performed in a 2.8 cm-diameter Oldershaw distillation column containing 40 trays, and the operating pressure was controlled at 0.97 psi (950 mmHg). A thermal conductivity detector gas chromatography (GC) was used to quantify the amount of chemical compounds.

[0032] FIG. 5 showed one example of the separation processes used in the study. The condensate feed CF-I comprised water and formic acid as shown in TABLE 1.

TABLE 1

[0033] The condensate feed CF-I was fed into the extraction vessel E-I along with the furfural extracting solvent FS-I. The liquid-liquid extraction took place in E-I vessel and separated an aqueous-rich stream R- 1 containing mainly water from a furfural-rich stream EX-I. When desired, the aqueous-rich stream R-I could be subjected to a stream stripper (not shown in FIG. 5) to recover furfural and some formic acid residues. The furfural-rich stream EX-I, comprising water, formic acid and furfural, was analyzed by GC to quantify the amount of recovered formic acid. As shown in TABLE 1 and FIG. 6, approximately at least 40% of the formic acid was recovered from the E- 1 extraction process.

[0034] The hydrolysate feed HYFD-2 comprised water, furfural, formic acid, sulfuric acid, levulinic acid and small amount of other unidentified acid as shown in TABLE 2.

TABLE 2

[0035] The hydrolysate feed HYFD-2 was fed into the extraction vessel E-2, along with furfural extracting solvent FS-2. The liquid-liquid extraction separated the aqueous-rich stream R-2 containing mainly water from the furfural-rich stream EX -2 containing furfural, formic acid and levulinic acid. When desired, the aqueous-rich stream R-2 was subjected to a stream stripper (not shown in FIG. 5) to recover furfural and some formic acid residues. The furfural-rich stream EX-2 was analyzed by GC to quantify the amount of recovered levulinic acid. As shown in TABLE 2 and FIG. 7, at least 90% of the levulinic acid and 40% or more of formic acid were recovered from the E-2 extraction process.

[0036] The furfural-rich stream EX-2 was fed to a first vacuum distillation D-I, wherein the levulinic acid was isolated as a bottom stream BOT-I from the overhead stream OVHD-I. When desired, the OVHD-I stream was subjected to a stream stripping (not shown in FIG. 5) to provide OVHD-I Light portion and OVHD-I Heavy portion. The compositions of each stream were quantitatively determined using GC analysis. (TABLE 3, FIG. 8). TABLE 3

[0037] The isolated overhead stream OVHD-I stream and the furfural -rich stream EX-I were fed into a second vacuum distillation D-2. When desired, the OVHD-I and EX-I streams could be combined prior to feeding into the distillation vessel D-2. During distillation, water and furfural formed a low boiling point azeotrope that was isolatable as an overhead stream OVHD-2 from the bottom stream BOT-2 containing formic acid and furfural. The OVHD-2 stream was subjected to a stream stripping (not shown in FIG. 5) to provide OVHD-2 Light portion and OVHD-2 Heavy portion. The compositions of each stream were quantitatively determined using GC analysis. (TABLE 4 and FIG. 9)

TABLE 4

[0038] The bottom stream BOT-2 was then subjected to a third vacuum distillation D- 3 to isolate the formic acid from furfural solvent. The distillation provided the overhead stream OVHD-3 containing formic acid that was isolatable from the bottom stream BOT-3 containing mainly furfural solvent. (TABLE 5 and FIG. 10)

TABLE 5

[0039] When desired, the recovered furfural solvent in the bottom stream BOT-3 may be recycled back to the extraction vessels E-I and E-2 and reused as the extracting solvents for the condensate and the hydrolysate, respectively.

[0040] While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. It is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.

Claims

We Claim:

1. A process for isolating levulinic acid from an aqueous mixture comprising furfural, formic acid, and levulinic acid, characterized by a step of extracting the levulinic acid from the aqueous mixture using furfural as an extracting solvent.

2. The process of Claim 1, further characterized by a step of isolating the levulinic acid from the furfural extracting solvent.

3. The process of Claim 1, further characterized by a step of extracting the formic acid from the aqueous mixture using the furfural extracting solvent.

4. The process of Claim 3, further characterized by a step of isolating the formic acid from the furfural extracting solvent.

5. The process of Claim 1, wherein the aqueous mixture is obtained from an acidic hydrolysis of biomass.

6. The process of Claim 5, wherein the biomass comprises a member selected from the group consisting of rice straw materials, woody plant materials, paper materials, cotton materials, lignocellulosic materials, corn stalks, bagasse, sugar-based materials, carbohydrate materials, and mixtures thereof.

7. A levulinic acid obtained by the process of Claim 2.

8. A formic acid obtained by the process of Claim 4.

9. A process for isolating levulinic acid from an aqueous mixture comprising furfural, formic acid, and levulinic acid; wherein the process includes steps of: (a) flashing the aqueous mixture to provide an aqueous condensate portion comprising formic acid and furfural; and a hydrolysate portion comprising formic acid, furfural and levulinic acid; (b) providing furfural as an extracting solvent; (c) feeding the condensate, the hydrolysate and the furfural solvent into an extraction vessel;

(d) performing liquid-liquid extraction in the extraction vessel to generate an aqueous-rich phase containing water, formic acid and furfural; and a furfural-rich phase containing formic acid, levulinic acid and furfural; and

(e) subjecting the furfural-rich phase into a first distillation vessel to provide a first overhead stream comprising water, formic acid and furfural; and a first bottom stream comprising levulinic acid.

10. The process of Claim 9, further comprising a step of distillation of the first bottom stream to provide purified levulinic acid.

11. The process of Claim 9, further comprising steps of:

(f) subjecting the first overhead stream into a second distillation vessel to provide a second bottom stream comprising furfural and a second overhead stream comprising water, furfural and formic acid; and

(g) feeding the second overhead stream into a third distillation vessel to isolate formic acid.

12. The process of Claim 11, further comprising a step of recycling a fraction of the furfural solvent obtained in step (f) back to the extraction vessel.

13. The process of Claim 9, further comprising steps of:

(i) subjecting the first overhead stream into a second distillation vessel to provide a second overhead stream comprising water-furfural azeotrope and a second bottom stream comprising furfural and formic acid; and

(ii) feeding the second bottom stream into a third distillation vessel to separate a third overhead stream comprising formic acid from a third bottom stream comprising furfural.

14. The process of Claim 13, further comprising a step of recycling a fraction of the furfural solvent obtained in step (ii) back to the extraction vessel.

15. The process of Claim 9, wherein the aqueous mixture is obtained from acidic hydrolysis of biomass.

16. The process of Claim 15, wherein the biomass comprises a member selected from the group consisting of rice straw materials, woody plant materials, paper materials, cotton materials, lignocellulosic materials, corn stalks, bagasse, sugar-based materials, carbohydrate materials, and mixtures thereof.

17. The process of Claim 9, further comprising a step of concentrating the hydro lysate prior to feeding into the extraction vessel.

18. The process of Claim 17, further comprising a step of filtering the concentrated hydrolysate prior to feeding into the extraction vessel.

19. A levulinic acid obtained by the process of Claim 9.

20. A levulinic acid obtained by the process of Claim 10.

21. A formic acid obtained by the process of Claim 1 l(f).

22. A formic acid obtained by the process of Claim 13(ii).

23. A process for isolating levulinic acid from an aqueous mixture comprising furfural, formic acid, and levulinic acid; wherein the process includes steps of: (a) flashing the aqueous mixture to provide an aqueous condensate portion comprising formic acid and furfural; and a hydrolysate portion comprising formic acid, furfural and levulinic acid;

(b) providing furfural as an extracting solvent;

(c) feeding the hydrolysate and the furfural solvent into a second extraction vessel; (d) performing liquid-liquid extraction in the second extraction vessel to generate a second aqueous-rich phase containing water, formic acid and furfural; and a second furfural-rich phase containing water, formic acid, furfural and levulinic acid; and (e) subjecting the second furfural-rich phase into a first distillation vessel to provide a first overhead stream comprising water, formic acid and furfural; and a first bottom stream containing levulinic acid.

24. The process of Claim 23, further comprising a step of distillation of the first bottom stream to provide purified levulinic acid.

25. The process of Claim 23, further comprising a step of stream stripping the second aqueous-rich phase.

26. The process of Claim 23, further comprising steps of :

(f) feeding the condensate and the furfural solvent into a first extraction vessel;

(g) performing liquid-liquid extraction in the first extraction vessel to generate a first aqueous-rich phase containing water, formic acid and furfural; and a first furfural- rich phase containing water, formic acid and furfural;

(h) subjecting the first overhead stream and the first furfural-rich phase into a second distillation vessel to provide a second overhead stream containing water and furfural, and a second bottom stream containing formic acid and furfural; and (i) feeding the second bottom stream into a third distillation vessel to provide a third overhead stream containing formic acid; and a third bottom stream containing spent furfural solvent.

27. The process of Claim 25, wherein the first overhead stream and the first furfural-rich phase are combined prior to feeding into the second distillation vessel.

28. The process of Claim 25, further comprising a step of recycling a fraction of the spent furfural solvent back to at least one of the first and the second extraction vessels.

29. The process of Claim 23, further comprising a step of stream stripping the first aqueous- rich phase.

30. The process of Claim 23, further comprising a step of concentrating the hydrolysate prior to feeding into the second extraction vessel.

31. The process of Claim 30, further comprising a step of filtering the concentrated hydrolysate prior to feeding into the second extraction vessel.

32. The process of Claim 23, wherein the aqueous mixture is obtained from acidic hydrolysis of biomass.

33. The process of Claim 32, wherein the biomass comprises a member selected from the group consisting of rice straw materials, woody plant materials, paper materials, cotton materials, lignocellulosic materials, corn stalks, bagasse, sugar-based materials, carbohydrate materials, and mixtures thereof.

34. A levulinic acid obtained by the process of Claim 23.

35. A levulinic acid obtained by the process of Claim 24.

36. A formic acid obtained by the process of Claim 26(i).