A process for producing mixture of furfurals and implementations thereof

Abstract

The present disclosure provides a process for producing a mixture of esters of 5- hydroxymethyl furfural (HMF), and halomethyl furfural (XMF), by contacting a biomass with a solvent in the presence of a catalyst for a period in the range of 1 minute to 5 hours, at a temperature in the range of 80 to 250 ℃.

Description

A PROCESS FOR PRODUCING MIXTURE OF FURFURALS AND IMPLEMENTATIONS THEREOFFIELD OF INVENTION

[0001] The present disclosure broadly relates to the field of biofuels. Particularly, the present disclosure relates to a process of producing a mixture of furfurals. More particularly, the present disclosure relates to producing a mixture of esters of 5- hydroxymethyl furfural (HMF), and halomethyl furfural (XMF), from whole or minimally processed or processed seaweed.BACKGROUND OF THE INVENTION

[0002] Fossil fuel is an umbrella term that covers multiple non-renewable energy resources, such as coal, crude oil and their products, natural and derived gases. They are carbon-based, and their combustion generates carbon dioxide, which accounts for nearly 65% of global emissions by gas. In 2022, fossil fuels alone accounted for 82% of the global energy consumption.

[0003] Alongside being primary sources for energy requirements, fossil fuels and derived petrochemicals have a myriad of other applications. They are raw materials for the production of several commodity chemicals and intermediate petrochemicals, such as ethylene, propylene, acetylene, benzene, and toluene, which are themselves feedstock for common household and commercial products used every day, such as plastics, textiles, electronics, personal care products, and pharmaceuticals. Fossil fuels are also substantial sources of ‘platform chemicals’ that are building blocks for producing other higher value-added chemicals. In 2004, the Department of Energy (DOE) identified 12 chemical building blocks and the updated list includes ethanol, furfural, 5-(hydroxymethyl)furfural (HMF), 2,5- furandicarboxylic acid (FDCA), glycerol, isoprene, succinic acid, 3- hydroxypropionic acid / aldehyde, levulinic acid (LA), lactic acid, sorbitol, and xylitol.

[0004] The finite nature, volatile prices, and adverse environmental effects of fossil fuels, coupled with the urge for transition to ‘net-zero emissions’, have prompted asteady shift to renewable resources for energy needs. In this context, biomass has been identified as a sustainable choice of feedstock to reduce dependence on fossil- fuel-based resources. Besides those naturally available, other sources of biomass are agricultural wastes (such as com stover, rice husk, and sugar cane bagasse), municipal solid wastes (MSW), and industrial waste, such as those from pulp and paper industries. As the concept of bio-refinery evolved, biomass feedstock has been processed and converted into a spectrum of products, such as platform chemicals and their respective value-added products. Global bio-based platform chemical market was estimated at US$ 17.6 Bn in 2023 and is forecasted to reach US$ 35.3 Bn by 2033.

[0005] Production of HMF and its hydrophobic congeners has been reported in prior art. Particularly, processes for synthesis of esters and ethers of HMF and 5- (halomethyl)furfurals (XMFs) from saccharides and pre-treated biomass have been described in prior art. US10259797B2 relates to a process for preparing a mixture comprising HMF and specific HMF esters. The process entails providing a starting mixture which includes one, two, or more carbohydrate compounds, a catalytically effective amount of one, two, or more alkali halide catalysts, and one or more carboxylic acid esters as the solvent or as a co-solvent for subjecting the starting mixture to reaction conditions so that a mixture comprising HMF and one or more HMF esters is obtained.

[0006] WO2023166503 Al describes a process for preparing an ester of HMF. The method comprises the addition of a C6 carbohydrate, an organic acid, and a salt, which is at most sparingly soluble in said organic acid to form a reaction mass. This is followed by heating and allowing the reaction to proceed, separating the salt from the liquid phase, and recovering a reaction product comprising an ester of HMF, further described as 5-(acetoxymethyl)furfural (AcMF). Embodiments illustrate the production of AcMF from fructose and sucrose.

[0007] US8795393B2 relates to a process for preparing a petroleum-alternative biofuel material, such as HMF, 5-alkoxymethyl-2-furfural, levulinic acid alkyl ester, etc. from a galactan extracted as a polysaccharide from marine algae. The galactan has been further described as comprising agar. A biofuel comprising atleast one of HMF and 5-alkoxymethyl-2-furfural is prepared by adding the galactan into a solvent together with at least one of an organic acid catalyst, an inorganic acid catalyst, a solid acid catalyst, or a metal catalyst.

[0008] Methods described in the prior arts for preparing furfurals and / or their esters utilize biomass-derived saccharides or lignocellulosic materials as substrates in illustrative examples. Processes that employ pure sugars, such as fructose as feedstock are disincentive to industrial scale production. In the case of lignocellulosic or woody biomass, lignin accounts for up to 30% of the material. Pre-treatment steps of saccharification and delignification of biomass feedstock are required before a directly usable substrate can be obtained. Feedstock, such as agricultural and municipal solid wastes require similar, if not greater, pre-treatment levels, adding to costs.

[0009] In view of the aforementioned issues, there is a need to develop sustainable, and economical methods for preparing furfurals and / or their esters from inexpensive and abundant biomass feedstock that preferably do not contain the lignin component and require minimal pretreatment.SUMMARY OF INVENTION

[0010] In an aspect of the present disclosure, there is provided a process for producing a mixture of esters of 5-(hydroxymethyl)furfural (HMF), and 5- (halomethyl)furfural (XMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours, at a temperature in the range of 80 to 250 °C to obtain a mixture of esters of HMF, and XMF.

[0011] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the disclosed subject matter, nor is it intended to be used to limit the scope of the disclosed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following drawings form a part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.

[0013] Figure 1 depicts the Thin Layer Chromatography (TLC) image of mixture of CMF and AcMF obtained by the process as described herein, alongside reference spots of CMF and AcMF, in accordance with the embodiments of the present disclosure.

[0014] Figure 2 depicts the FTIR (Fourier-transform infrared spectroscopy) spectra of CMF and AcMF, in accordance with the embodiments of the present disclosure.

[0015] Figure 3 depicts the 'H-NMR (Proton nuclear magnetic resonance) spectra of CMF and AcMF, in accordance with the embodiments of the present disclosure.

[0016] Figure 4 depicts the TLC image of purified CMF and AcMF synthesised under microwave conditions alongside reference samples CMF and AcMF, in accordance with the embodiments of the present disclosure.

[0017] Figure 5 depicts the TLC image of purified FMF and CMF, spotted alongside reference AcMF visualized under UV light (left) and after DNP staining (right), in accordance with the embodiments of the present disclosure.

[0018] Figure 6 depicts the FT-IR spectrum of FMF, in accordance with the embodiments of the present disclosure.

[0019] Figure 7 depicts the 'H-NMR spectrum of FMF in CDCL, in accordance with the embodiments of the present disclosure

[0020] Figure 8 depicts the TLC image of purified PrMF and CMF spotted alongside reference AcMF visualized under UV light (left) and after DNP staining (right), in accordance with the embodiments of the present disclosure.

[0021] Figure 9 depicts the FT-IR spectrum of PrMF, in accordance with the embodiments of the present disclosure.

[0022] Figure 10 depicts the 'H-NMR spectrum of PrMF in CDCL, in accordance with the embodiments of the present disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0023] Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features. Definitions

[0024] For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

[0025] The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

[0026] The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”.

[0027] Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps.

[0028] The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.

[0029] The term “seaweed” or “macroalgae”, used interchangeably throughout the present disclosure, refers to the macroscopic, multicellular marine plants that are naturally found in water bodies, such as oceans, seas, rivers, lakes, and ponds or cultivated. They include the species of Rhodophyta (red algae), Phaeophyta (brown algae), and Chlorophyta (green algae). Examples of species include but are notrestricted to those belonging to the genus of Kappaphycus, Halymenia, Gigartina, Chondrus, Gelidium, Gracilaria, Porphyra, Eucheuma, Fucus, Laminaria, Sargassum, Solieria, Hypnea, Mastocarpus, Furcerllaria, Iridea, Anatheca, Meristotheca, Ahnfeltia, Gynmogongrus, Phyllophora, or Ulva.

[0030] The term “biomass” or “substrate” as used herein refers to any organic material that may be obtained from plants, specifically from macroalgae or seaweed. The seaweed can be fresh seaweed or dried seaweed. Fresh seaweed refers to seaweed freshly harvested directly from its natural marine environment or habitat. The natural environment or habitat may accordingly be selected from a group comprising but not limiting to water bodies, such as oceans, seas, rivers, lakes, and ponds. Dried seaweed refers to seaweed biomass with moisture content less than or equal to 50% and is prepared by drying the fresh seaweed. Biomass can be in a form including but not limited to granules, flakes, powders, chips and whole dried seaweed as such. The seaweed biomass used for the experiments as described in the present invention were obtained from Bali, Indonesia.

[0031] Further, the biomass may be used as “whole biomass” that is “unprocessed biomass” (without any processing) or may be subjected to minimal processing. The term “minimally processed biomass” refers to either fresh or dried seaweed that may be subjected to further physical processes, including but not limited to cleaning of physical impurities, washing with water or solvent, squeezing, grinding, crushing, separation, rehydration, drying, or milling. Such minimally processed or unprocessed biomass for the purposes of the present disclosure is a biomass having an acid insoluble matter of at least 2%, preferably more than 5.

[0032] For the purposes of the present invention, the minimally processed biomass is minimally processed seaweed or macroalga. Similarly, the unprocessed biomass is unprocessed seaweed or macroalga.

[0033] The terms “processed biomass”, “processed seaweed” or “processed macroalgae” refers to semi-refined forms of the macroalgae or polysaccharide, obtained by subjecting the unprocessed or minimally processed seaweed or macroalgae to methods of processing known in the art, that retains most of the acid insoluble matter and the macroalgal polysaccharide in the seaweed. The processingmethods include but are not limited to alkali and / or acid treatment at high temperatures, drying and milling. The acid insoluble matter in processed biomass or processed seaweed is preferably more than 2%. Examples include but are not limited to semi refined carrageenans (SRC), such as - kappa semi refined carrageenan (kappa SRC), iota semi refined carrageenan (iota SRC), lambda semi refined carrageenan (lambda SRC) or hybrid forms thereof, semi refined forms of agar, agarose, fucoidan, porphyran, alginate, and ulvan.

[0034] The term “refined biomass” or “pure substrate” as used herein, refers to refined forms of the macroalgae or polysaccharide, obtained by subjecting the processed biomass or semi refined forms of the macroalgae or polysaccharide to further extraction and refining methods known in the art. These refined macroalgal polysaccharides contain lower content of acid insoluble matter, preferably less than 2%. Examples include but are not limited to refined forms of carrageenans such as - kappa refined carrageenan (kappa RC), iota refined carrageenan (iota RC), lambda refined carrageenan (lambda RC) or hybrid forms thereof and refined forms of agar, agarose, fucoidan, porphyran, alginate, and ulvan.

[0035] The term “acid insoluble matter” refers to the proportion of the substrate or the biomass, that remains undissolved or unhydrolyzed after treatment with a mineral acid at high temperature. Acid insoluble matter of the substrate or the biomass is dependent on the extent of processing and was measured as per method described in the Combined Compendium Of Food Additive Specifications, established by the Joint FAO / WHO Expert Committee on Food Additives (JECFA). In the context of the present invention, the biomass or substrates utilized contain an acid insoluble matter of at least 2%.

[0036] The term “carbon content” as used herein refers to the amount or proportion of carbon, either by weight or percentage, that is present in a material or substance. Based on the material, it can be estimated by various methods known in the art, including but not limited to combustion or elemental analysis and spectroscopy.

[0037] The term “carbon capture” refers to the extent to which the carbon contained in the substrate or biomass has been recovered or re-captured in the products. As the substrate or biomass is the source of carbon, estimation considers the maximumnumber of carbons that can be contributed by the biomass for product formation, the carbon content and the mass of the biomass as well as the product. Carbon capture or recovery is an effective measure for representing the sustainability of a product or a process.

[0038] The term “crude mixture” refers to an unreacted mixture of reactants or a partially reacted mixture comprising products and reactants or a mixture comprising products, all present in an unrefined state.

[0039] In the present invention, the carbon in the biomass is captured in the form of furfurals. Therefore, the combined as well as separate yields are represented as carbon captured in the form of esters of HMF, and 5-( halomethyl)furfural or as the carbon recovered from the biomass, in these products, on a moisture free basis. The yields of the esters of HMF, and 5-(halomethyl)furfural are also represented on weight basis of the moisture free biomass or substrate.

[0040] Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.

[0041] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.

[0042] As discussed, in the background, the patents WO2023166503 Al and US8795393B2 focus on the utilization of specific carbohydrate sources or polysaccharides extracted from seaweeds as starting materials for the synthesis of HMF, XMF and other platform chemicals. The usage of such refined starting materials will result in increased production costs. Also, continuous processes are feasible only with lower reaction times and minimally processed seaweed biomass.

[0043] Further, reported processes entail longer reaction times and usage of multiple reaction agents, adding to cost limitations and process limitations for large scale production. Particularly, synthesis methods for halomethyl furfurals, such as CMF, reported in prior literature, utilize biphasic reaction conditions and concentrated aqueous acid catalysts. Moreover, halomethyl furfurals are highly hydrophobic and unstable. It is necessary to keep CMF cold and dry for long-term storage. The high reactivity of CMF also makes it difficult to handle and isolate from the reaction mixture. Frequent intermittent extraction is required to prevent the decomposition of CMF in the reaction medium.

[0044] Further, HMF is highly hydrophilic and unstable, rehydrating easily to formic and levulinic acid. Recent toxicological studies have demonstrated that at high concentrations, HMF can adversely affect human health, such as irritation of the mucous membranes, skin, upper respiratory system, and eyes, as well as neurodegenerative, diabetes, and cardiovascular diseases. Hence, esters of HMF, such as AcMF, present as an eco-friendly, hydrophobic, thermally stable, and easily separable alternative. They do not pose toxic effects to human health and like XMFs - can be subject to further chemistries to provide a variety of commercially important compounds.

[0045] In view of the aforementioned issues, there is a need to develop methods for preparing esters of HMF along with XMFs (such as CMF) directly from marine biomass as feedstocks. In this respect, macroalgae or seaweed - considered third- generation biomass, is a desirable feedstock material, since it is non-competitive with food, does not require cultivable land, and can be farmed sustainably on a large scale.

[0046] Therefore, in an embodiment of the present disclosure, there is provided a one-pot, monophasic reaction process for concomitant production of esters of HMF, and XMF from seaweed biomass. The resultant stable mixture of esters of HMF, and XMF can be subsequently converted via various chemistries to obtain derivative products, including but not limited to FDCA, 2,5-furandimethanol (FDM), 2, 5 -dimethylfuran (DMF), 2, 5 -diformylfuran (DFF), 5-hydroxyferulic acid (HF A), linear alkanes, branched alkanes, and cycloalkanes. XMF, such as CMF andthe ester of HMF, such as AcMF, can be transformed into these high-value chemicals individually as known in the literature. The differential stability (e.g., thermal, hydrolytic, storage) of CMF and AcMF can be advantageous in transforming the mixture into two different products in the same pot.

[0047] In an embodiment of the present disclosure, there is provided a process for producing a mixture of esters of 5-(hydroxymethyl)furfural (HMF), and 5- (halomethyl)furfural (XMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours, at a temperature in the range of 80 to 250 °C to obtain a mixture of esters of 5-(hydroxymethyl)furfural, and 5-(halomethyl)furfural.

[0048] In the process as described herein, the biomass is contacted with the solvent in the presence of the catalyst for a period in the range of 1 minute to 5 hours, 5 minutes to 5 hours, 15 minutes to 5 hours, 20 minutes to 5 hours, 25 minutes to 5 hours, or 30 minutes to 5 hours. In some embodiments, the biomass is contacted with the solvent in the presence of the catalyst for a period in the range of 1 minute to 4 hours, 1 minute to 3 hours or 40 minutes to 3 hours.

[0049] In the process as described herein, the biomass is contacted with the solvent in the presence of the catalyst at a temperature in the range of 80 to 250 °C, 80 to 240 °C, 80 to 230 °C, or 80 to 220 °C. In some embodiments, the biomass is contacted with the solvent in the presence of the catalyst at a temperature in the range of 90 to 250 °C, 150 to 250 °C or 160 to 250 °C.

[0050] In a preferred embodiment, the biomass is contacted with the solvent in the presence of the catalyst at a temperature of 120 °C for a period of 4 hours.

[0051] In another embodiment of the present disclosure, there is provided a process for producing a mixture of esters of 5 -(hydroxy methyl)furfural (HMF), and 5- (halomethyl)furfural (XMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 220 °C to obtain a mixture of esters 5 -hydroxymethyl furfural, and halomethyl furfural.

[0052] In an embodiment of the present disclosure, the esters of 5 -hydroxymethyl furfural (HMF) are selected from 5-acetoxymethylfurfural (AcMF), 5-(formyloxymethyl)furfural (FMF), 5-(propionyloxymethyl)furfural (PrMF), 5- (butyryloxymethyl)furfural (BuMF), 5-(isobutyryloxymethyl)furfural (i-BuMF), 5- (pivaloyloxymethyl)furfural (PvMF), HMF esters of valeric acid, isovaleric acid, caproic acid, isocaproic acid, 2-hexanoic acid, enanthic acid, 2-heptanoic acid, caprylic acid, 2-octanoic acid, pelargonic acid, 2-nonanoic acid, caproic acid 2- decanoic acid, acrylic acid, crotonic acid, 3-methylcrotonic acid, 2-ethylbutyric acid, 3 -methylvaleric acid, sorbic acid, 2-ethylhexanoic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2,2-dimethylhexanoic acid, 2,2- dimethylheptanoic acid, 2,2-dimethyloctanoic acid,2,2-dimethylnonanoic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, malic acid, fumaric acid, maleic acid, pyruvic acid, fumaric acid, itaconic acid, adipic acid, suberic acid, azelaic sebacic acid, pimelic acid, methyl malonic acid, methyl succinic acid, methyl maleic acid, dimethyl maleic acid, methyl adipic acid, oleic acid, or combinations thereof, preferably the esters of HMF is selected from 5- acetoxymethylfurfural (AcMF), 5-(formyloxymethyl)furfural (FMF), or 5- (propi ony 1 oxy methy l)furfural (PrMF ) .

[0053] In an exemplary embodiment, the ester of HMF is 5- (acetoxymethyl)furfural (AcMF). In another exemplary embodiment the ester of HMF is 5-(formyloxymethyl)furfural (FMF). In yet another exemplary embodiment the ester of HMF is 5-(propionyloxymethyl)furfural (PrMF).

[0054] In an embodiment of the present disclosure, the 5-(halomethyl) furfural (XMF) is 5-(chloromethyl)furfural (CMF).

[0055] In some embodiments, the ester of HMF is 5-acetoxymethylfurfural (AcMF) and the 5-(halomethyl) furfural (XMF) is 5-(chloromethyl)furfural (CMF). In some other embodiments, the ester of HMF is 5-(formyloxymethyl)furfural (FMF) and the halomethyl furfural (XMF) is 5-(chloromethyl)furfural (CMF). In yet another embodiment the ester of HMF is 5-(propionyloxymethyl)furfural (PrMF) and the 5-(halomethyl) furfural (XMF) is 5-(chloromethyl)furfural (CMF).

[0056] In a first preferred embodiment of the present disclosure, there is provided a process for producing a mixture of 5-(acetoxymethyl) furfural (AcMF) and 5- (chloromethyl) furfural (CMF), the process comprising: contacting a biomass witha solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 250 °C to obtain a mixture of 5-(acetoxymethyl) furfural (AcMF) and 5-(chloromethyl) furfural (CMF).

[0057] In a second preferred embodiment of the present disclosure, there is provided a process for producing a mixture of 5-(formyloxymethyl)furfural (FMF) and 5-(chloromethyl) furfural (CMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 250 °C to obtain a mixture of 5-(formyloxymethyl)furfural (FMF) and 5-(chloromethyl) furfural (CMF).

[0058] In a third preferred embodiment of the present disclosure, there is provided a process for producing a mixture of 5-(propionyloxymethyl)furfural (PrMF) and 5-(chloromethyl) furfural (CMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 250 °C to obtain a mixture of 5-(propionyloxymethyl)furfural (PrMF) and 5-(chloromethyl) furfural (CMF).

[0059] In an embodiment of the present disclosure, the biomass is obtained from macroalgae.

[0060] In an embodiment of the present disclosure, the amount of biomass is in a weight range of 2 to 25% with respect to the total weight of the reaction mixture. In another embodiment of the present disclosure, the amount of biomass is in a weight range of 5 to 20%, 10 to 24%, 15 to 25%, or 16 to 25%, with respect to the total weight of the reaction mixture. In yet another embodiment of the present disclosure, the amount of biomass is in a weight range of 10 to 18%, with respect to the total weight of the reaction mixture

[0061] In an embodiment of the present disclosure, the macroalgae is selected from members of Rhodophyta, Chlorophyta or Phaeophyta. In another embodiment of the present disclosure, the macroalgae is selected from species of, including but not limited to, Kappaphycus, Halymenia, Gigartina, Chondrus, Gelidium, Gracilaria,Porphyra, Eucheuma, Fucus, Laminaria, Sargassum, Solieria, Hypnea, Mastocarpus, Furcerllaria, Iridea, Anatheca, Meristotheca, Ahnfeltia, Gynmogongrus, Phyllophora, or Ulva. In a preferred embodiment of the present disclosure, the macroalgae is selected from Eucheuma cottonii, Eucheuma denticulatum (spinosum), Euchuema isiforme, Kappaphycus alvarezii, Kappaphycus striatus, Gracilaria fisheri, gracilaria dura, Gracilaria edulis, Gracilaria gracilis, Gracilaria hainanensis, Gracilaria lemaneiformis, Gracilaria viridis, Halymenia durvillaea, Chondrus crispus, Solieria chordalis, Porphyra purpurea, Hypnea musciformis, Solieria fdiformis, Mastocarpus stellatus, Mastocarpus papillatus, Porphyra capensis, Gelidium amansii, or combinations thereof

[0062] In an embodiment of the present disclosure, the solvent is aliphatic carboxylic acid selected from formic acid, acetic acid, propanoic acid, butanoic acid, valeric acid, isovaleric acid, caproic acid, isocaproic acid, 2-hexanoic acid, enanthic acid, 2-heptanoic acid, caprylic acid, 2-octanoic acid, pelargonic acid, 2- nonanoic acid, caproic acid 2-decanoic acid, acrylic acid, crotonic acid, 3- methylcrotonic acid, 2-ethylbutyric acid, 3 -methylvaleric acid, sorbic acid, 2- ethylhexanoic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2,2- dimethylhexanoic acid, 2,2-dimethylheptanoic acid, 2,2-dimethyloctanoic acid, 2,2-dimethylnonanoic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, malic acid, fumaric acid, maleic acid, pyruvic acid, fumaric acid, itaconic acid, adipic acid, suberic acid, azelaic sebacic acid, pimelic acid, methyl malonic acid, methyl succinic acid, methyl maleic acid, dimethyl maleic acid, methyl adipic acid, oleic acid, or combinations thereof, preferably acetic acid; and the amount of solvent is in a weight range of 70 to 97%, with respect to the total weight of the reaction mixture. In yet another embodiment of the present disclosure, the solvent is acetic acid, preferably glacial acetic acid.

[0063] In an embodiment of the present disclosure, the catalyst is selected from ion exchange resins, organic acids, inorganic acids, salts, Lewis acids, zeolites, clays, metal catalysts, enzymes, organic ammonium salts, or combinations thereof.

[0064] In an embodiment of the present disclosure, the catalyst is an acidic ion exchange resin; and the amount of catalyst is in a weight range of 1 to 5%, 2 to 5%, 2.2 to 5%, 2.4 to 5%, 2.5 to 5%, or 2.5 to 4.5%, with respect to the total weight of the reaction mixture.

[0065] In an embodiment of the present disclosure, the process further comprises purifying the mixture of esters of 5-(hydroxymethyl)furfural, and 5- (halomethyl)furfural to obtain ester of 5-(hydroxymethyl)furfural, and 5- (halomethyl)furfural, individually. In another embodiment, the process further comprises purifying the mixture of 5 -(acetoxy methyl)furfural (AcMF) and 5- (chloromethyl)furfural (CMF) to obtain 5-(acetoxymethyl)furfural (AcMF), and 5- (chloromethyl)furfural (CMF), individually. In yet another embodiment, the process further comprises purifying the mixture of 5-(formyloxymethyl)furfural (FMF) and 5-(chloromethyl)furfural (CMF) to obtain 5-(formyloxymethyl) furfural (FMF), and 5-(chloromethyl)furfural (CMF), individually. In yet another embodiment, the process further comprises purifying the mixture of 5- (propionyloxymethyl)furfural (PrMF) and 5-(chloromethyl)furfural (CMF) to obtain 5-(propionyloxymethyl)furfural (PrMF), and 5-(chloromethyl)furfural (CMF), individually.

[0066] In an embodiment of the present disclosure, the purification is carried out by a technique selected from filtration, centrifugation, distillation, solvent extraction, trituration chromatographic techniques, adsorption, sublimation, recrystallization, or combinations thereof. In another embodiment of the present disclosure, the purification is carried out by a technique selected from filtration, distillation, or combinations thereof.

[0067] In an embodiment of the present disclosure, post purification, the ester of 5- hydroxymethyl furfural, and halomethyl furfural is further subjected to analyses selected from IR spectroscopy, mass spectroscopy, NMR spectroscopy, UV visible absorption spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy, ion exchange chromatography, gas chromatography, thin-layer chromatography (TLC), flash chromatography, thermal analysis, chemical andbiochemical assays, atomic absorption spectroscopy, CHNS, sulfur content, proximate and ultimate analysis, microscopy, or combinations thereof.

[0068] In an embodiment of the present disclosure, the process further comprises oxidizing the mixture of AcMF and CMF to obtain 2,5-furan-dicarboxylic acid (FDCA).

[0069] In an embodiment of the present disclosure, there is provided a process for producing 2,5-furan-dicarboxylic acid (FDCA), the process comprising: a) contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 250 °C, followed by purification to obtain a mixture of 5- (acetoxymethyl)furfural (AcMF) and 5-(chloromethyl)furfural (CMF); and b) oxidizing the mixture of 5-(acetoxymethyl)furfural (AcMF) and 5- (chloromethyl)furfural (CMF) to obtain 2,5-furan-dicarboxylic acid (FDCA).

[0070] In an embodiment of the present disclosure, the oxidation in step (b) is carried out using an oxidizing agent selected from nitric acid; catalysts based on manganese, cobalt, or bromine; or combinations thereof. In another embodiment, the oxidizing agent is aqueous nitric acid.

[0071] In an embodiment of the present disclosure, the yield of FDCA is in the range of 60 to 90%, with respect to the AcMF and CMF.

[0072] In an embodiment of the present disclosure, there is provided a process for producing a mixture of 5-(acetoxymethyl)furfural (AcMF) and 5- (chloromethyl)furfural (CMF), the process comprising: a) contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours at a temperature in the range of 80 to 250 °C, to obtain a first crude mixture of 5-(acetoxymethyl)furfural (AcMF) and 5- (chloromethyl)furfural (CMF); b) filtering the first crude mixture to separate solid fraction comprising humin, and a liquid filtrate; c) distilling the liquid filtrate to recover the solvent, and to obtain a second crude mixture; and d) extracting the second crude mixture using an organic solvent selected from chloroform, dichloromethane, di chloroethane, ethyl acetate or combinations thereof, to obtaina mixture of 5-(acetoxymethyl)furfural (AcMF) and 5-(chloromethyl)furfural (CMF).

[0073] In an embodiment of the present disclosure, there is provided a process as disclosed herein above, wherein the temperature at which the reaction is performed may vary but, in general, can be carried out at temperatures ranging from ambient to about 300°C. Temperature control can be achieved by means including but not limited to processing in an extruder, furnace, convection oven, microwaves, infrared heating, solar energy, heat exchangers, and direct or indirect contact with steam.

[0074] In an embodiment of the present disclosure, the process as described herein may be out as a batch, semi -batch, or continuous process.

[0075] In an embodiment of the present disclosure, the biomass is selected from unprocessed biomass, minimally processed biomass, processed biomass, or combination thereof, having an acid insoluble matter of at least 2%, with respect to the total weight of the biomass.

[0076] In an embodiment of the present disclosure, the process as described herein for producing a mixture of esters of 5 -(hydroxy methyl)furfural (HMF), and 5- (halomethyl)furfural (XMF), captures at least 3% of carbon in the biomass into a mixture of esters of HMF, and XMF of which at least 1% of carbon is present as XMF. In another embodiment, the process captures at least 3% of carbon in the biomass into AcMF, and CMF of which at least 1% of carbon is present as CMF.

[0077] In the process as described herein, the mixture of esters of HMF, and XMF has a yield of at least 1.5%, with respect to the total weight of the biomass on a moisture free basis.

[0078] In an embodiment of the present disclosure, the process as described herein for producing a mixture of esters of 5 -(hydroxy methyl)furfural (HMF), and 5- (halomethyl)furfural (XMF), is performed without the addition of halide salts.

[0079] Although the subject matter has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the subject matter, will become apparent to persons skilled in theart upon reference to the description of the subject matter. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present subject matter as defined.EXAMPLES

[0080] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may vary.Experiment 1: Production and Characterization of a mixture of ester of 5- (hydroxymethyl)furfural and CMF from biomass1.1. Process of production of mixture of ester of 5-(hydroxymethyl)furfural and CMF

[0081] In a glass pressure reactor, biomass (2 to 25%, seaweed biomass used in the examples was sourced from Indonesia, with 5 to 35% moisture content), dispersed in a solvent (70 to 97%) in the presence of a strongly acidic cation exchange resin (Amberlyst -15: catalyst, 1-5%), was reacted at a temperature of between 80 to 250 °C with a residence time of 1 minute to 5 hours. The choice of solvent is dependent on ester of 5-HMF to be synthesised. For AcMF, the solvent is glacial acetic acid, whereas for FMF, the solvent used is formic acid. After cooling to room temperature, the first crude mixture was subjected to vacuum filtration to separate the solid fraction and liquid filtrate. The liquid filtrate obtained was then subjected to distillation under vacuum at around 30 °C to separate the solvent and to obtain a second crude mixture. The second crude mixture was then diluted with chloroform(organic solvent) followed by deionized water and subjected to extraction with chloroform. The organic phase in chloroform was then dried over anhydrous Na2SO4 to remove moisture and evaporated in a rotary evaporator to get the product mixture of ester of 5-(hydroxymethy) furfural (AcMF, or FMF) and 5- (chloromethyl)furfural (CMF), which was further characterized and identified.

[0082] For the production of PrMF (ester of 5-(hydroxymethyl)furfural), a similar reaction, but with propionic acid as the solvent, was set up in a 100 mL ACE glass pressure reactor fitted Teflon cap in a preheated oil bath at 120 °C for 4 h. After the reaction, the reaction mixture was cooled down to room temperature. The excess propionic acid was neutralized using NaHCOs solution or distilled off under reduced vacuum. The crude products were extracted using chloroform and passed through small plug of silica to get pure CMF and PrMF.1.2. Process of production of mixture of ester of 5-(hydroxymethyl)furfural, and CMF in microwave assisted reactions

[0083] Biomass, and Amberlyst - 15 (catalyst) and glacial acetic acid (solvent for synthesis of AcMF; 70 to 97%) were taken in the microwave reaction vessel and sealed with a septum, placed in microwave apparatus, and the solution was heated at 180 to 220 °C with continuous stirring (300 rpm) for 1 min to 30 min. The mixture was cooled down to room temperature upon completion of the reaction, and pressure released by automatic ventilation of the microwave oven to obtain the first crude mixture. The solid fraction and liquid filtrate were separated through filtration of the first crude mixture. The liquid filtrate obtained was then subjected to distillation under vacuum at around 30 °C to separate acetic acid (solvent) and obtain a second crude mixture. The second crude mixture was then diluted with chloroform (organic solvent) followed by deionized water and subjected to extraction with chloroform. The organic phase in chloroform was then dried over anhydrous ISfeSCU (2 g) to remove moisture and evaporated in a rotary evaporator to get the product mixture of AcMF and CMF with some impurities.

[0084] The following examples as illustrated in Table 1 were performed and the data / result for the same is provided in Table 2. Table 3 illustrates the acid insolublematter in different biomass as used in the different examples. In the Example nos.1 to 14 and 17 to 19, glacial acetic acid was used as solvent for production of mixture of ACMF and CMF; in Example no. 15, formic acid was used as solvent for production of mixture of FMF and CMF; and in Example no. 16, propionic acid was used as solvent for production of mixture of PrMF and CMF. Example nos. 20 to 24 are comparative examples where pure or refined substrate was reacted with glacial acetic acid.Table 1: Examples for production of mixture of esters of 5 -(hydroxymethyl) furfural (AcMF, FMF, PrMF) and 5-(chloromethyl) furfural (CMF)Table 2: Result / observation for the Examples in Table 1Table 3: Acid Insoluble matter in different substrates / biomass used in examples ofTable 1Observation: As can be observed from the data illustrated in Table 1 and Table 2, the unprocessed biomass or minimally processed biomass or processed biomass (Example nos. 1 to 19) when subjected to the process conditions as described in the present disclosure, provided a product mixture of ester of 5- (hydroxymethyl)furfural (AcMF, FMF PrMF) and 5-(chloromethyl)furfural (CMF). On the other hand, for the refined substrates / biomass, only AcMF was detected in the crude product mixture, while CMF was not detected (Example nos. 20 to 24).1.3. Characterization of product mixture of 5-hydroxyxymethylfurfural and 5- (chloromethyl)furfural (CMF)

[0085] Thin Layer Chromatography (TLC), proton nuclear magnetic resonance spectrometry (1H NMR, 800 MHz Bruker Ascend™ spectrometer), and Fourier- transform infrared spectroscopy (FTIR) techniques were used to characterize and validate the presence of 5-(acetoxymethyl)furfural (AcMF) and 5-(chloromethyl) furfural (CMF) in a representative product mixture as obtained in Example 3 of Table 1 and 2.

[0086] The product mixture, comprising CMF and AcMF was subjected to purification using column chromatography (silica gel, 60 - 120 mesh) with chloroform as eluent followed by rotary evaporation at 50 °C to yield the pure compounds of CMF and AcMF. TLC was used to reaffirm the identity of the pure compounds.

[0087] TLC: TLC was done to identify the main components in the product mixture prepared using the method described herein above. The mixture was spotted on aTLC plate along with pure standards for CMF and AcMF and then placed in a chamber containing organic solvent (mixture of hexane and ethyl acetate or chloroform), which allowed it to develop. The plate was removed once eluted solvent front neared the top and was allowed to dry. Staining was carried out to visualize the spots on the TLC plate.

[0088] Two clear spots corresponding to both the pure standards were observed in the sample (Figure 1). Based on this, the components of the product mixture were identified as AcMF and CMF. Further, TLC identified the components of the product mixture as AcMF and CMF (obtained in Example no. 17 of Table 1 and 2) as shown in Figure 4 for microwave assisted reaction.

[0089] Similarly, other esters of HMF, such as, FMF, PrMF, and CMF, were purified and TLC analysis was done by spotting alongside AcMF samples.

[0090] As shown in Figure 5, TLC image reveals appearance of distinct spots for products as obtained in Example no. 15 of Table 1 and 2. FMF appears below CMF and AcMF spots, confirming the formation of FMF and its chemical distinction from AcMF and CMF.

[0091] Further, as shown in Figure 8, TLC reveals appearance of distinct spots of products as obtained in Example 16 of Table 1 and 2. The spot of PrMF appears between that of AcMF and CMF.

[0092] Proton nuclear magnetic resonance spectrometry (1HNMR): Proton nuclear magnetic resonance spectrometer (1H NMR, 800 MHz Bruker Ascend™ spectrometer, solvent - CDCL) was used to confirm the structure and identity of the purified reaction products, as esters of HMF, and CMF with a selectivity of > 80 %. Chemical shifts were expressed in ppm using deuterium labelled chloroform as the internal standard for 1H NMR. The 'H NMR spectra of AcMF, as obtained in Example no. 3 of Table 1 and 2 (Figure 3), showed characteristic signals for the acetyl group (2.05 ppm, CHs, s, 3H), aldehyde proton (9.53 ppm, CHO, s, 1H), furfuryl group protons (5.07 ppm, CH2, s, 2H), and aromatic protons (7.14 ppm, Fr- H, d, 1H; 6.51 ppm, Fr-H, d, 1H). Similarly, CMF's 'H NMR spectrum displayed signals for the chloromethyl group (4.60 ppm, CH2-CI, s, 2H), aldehyde proton (9.63 ppm, CHO, s, 1H), and aromatic protons (7.20 ppm, Fr-H, d, 1H; 6.58 ppm,Fr-H, d, 1H). The 'H NMR spectrum in Figure 7 confirmed the formation of FMF (as obtained in Example no. 15 of Table 1 and 2), with signals for the aldehyde proton (9.46 ppm, CHO, s, 1H), formyl proton (7.97 ppm, H-COOCEE, s, 1H), furfuryl methyl protons (5.07 ppm, CFL, s, 2H), and aromatic protons (7.11 ppm, Fr-H, d, 1H; 6.51 ppm, Fr-H, d, 1H). In Figure 10, the 'HNMR spectrum supported the formation of 5-(propionyloxy methyl)furfural (PrMF) (obtained in Example no. 16 of Table 1 and 2), with signals for the aldehyde proton (9.64 ppm, CHO, s, 1H), furfuryl methyl group (5.13 ppm, CH2, s, 2H), aromatic protons (7.22 ppm, Fr-H, d, 1H; 6.59 ppm, Fr-H, d, 1H), and propionic group protons (2.38 ppm, CH2-CO, q, 2H; 1.16 ppm, CH3-CH2-CO, t, 3H). The products formed could also be detected by Gas chromatography-mass spectrometry (GC-MS) analysis.

[0093] Fourier-transform infrared spectroscopy (FT-IR): Fourier-transform infrared spectroscopy (FT-IR ATR, Perkin Elmer spectrometer, in the range 4500 - 450 cm'1) was also used to confirm the structure and identify the purified reaction products, as esters of HMF and CMF. The FT-IR spectra of HMF esters and CMF are presented in Figures 2, 6, and 9.

[0094] AcMF's FT-IR spectrum of Example no. 3 from Table 1 and 2 (Figure 2) showed characteristic peaks for C-H stretching, ester C=O stretching, and aldehyde C=O stretching at 2914, 1745 and 1696 cm'1, respectively confirming AcMF formation. Similarly, CMF's spectrum (Ffigure 2) displayed peaks for C-H stretching (2914 cm '( aldehyde C=O stretching (1696 cm '( and C-Cl stretchingsupporting CMF formation.

[0095] The FT-IR spectrum in Figure 6 confirmed FMF formation (from Example no. 15 of Table 1 and 2) with peaks for C-H stretching (2924 cm '( ester C=O stretching (1729 cm '( and aldehyde C=O stretching (1680 cnr1).

[0096] Figure 9 shows PrMF's (as obtained in Example no. 16 of Table 1 and 2) spectrum with peaks for C-H stretching, ester C=O stretching and aldehyde C=O stretching appeared at 2921 cm 17411680 cm respectively, indicating PrMF formation.Experiment 2: Production of FDCA from AcMF and CMF mixture

[0097] A sealed glass reactor was charged with CMF and AcMF mixture (0.250 g each) and 5 ml of cone, nitric acid (HNO3, 69% aqueous) and the mixture was heated at 80-90 °C with stirring at 250 rpm for 6 h. 5 mL of HNO3 was added again and continued stirring with heating for an additional 6 h. The mixture was then carefully concentrated in a rotary evaporator, to precipitate solid FDCA. The solid product can be washed with cold water if required. Yield of FDCA = 0.201 g (40% by weight).ADVANTAGES OF THE PRESENT DISCLOSURE

[0098] The present disclosure provides a process of producing a mixture of esters of 5-(hydroxymethyl)furfural (HMF), and halomethyl furfural (XMF), particularly 5-(chloromethyl)furfural (CMF) from whole or minimally processed or processed seaweeds / macroalgae. The present disclosure has the ability to co-produce the XMF, more specifically 5-(chloromethyl)furfural (CMF) under the reaction conditions to produce esters of HMF without the addition of halide salts or halogenated solvents that would normally be required to produce CMF.

[0099] In addition, the present disclosure facilitates the synthesis of products in lesser reaction times compared to conventional processes. The present disclosure highlights that the extraction of polysaccharides from seaweed is not imperative. The reaction is carried out in a monophasic solvent system, enabling easy solvent recovery by distillation.

Claims

I / We Claim:

1. A process for producing a mixture of esters of 5-(hydroxymethyl)furfural (HMF), and 5-(halomethyl)furfural (XMF), the process comprising: contacting a biomass with a solvent in the presence of a catalyst, in a reaction mixture, for a period in the range of 1 minute to 5 hours, at a temperature in the range of 80 to 250 °C to obtain a mixture of esters of 5- hydroxymethyl furfural, and halom ethyl furfural.

2. The process as claimed in claim 1, wherein the esters of HMF is selected from 5-acetoxymethylfurfural (AcMF), 5-(formyloxymethyl)furfural (FMF), 5-(propionyloxymethyl)furfural (PrMF), 5- (butyryloxymethyl)furfural (BuMF), 5-(isobutyryloxymethyl)furfural (i- BuMF), 5-(pivaloyloxymethyl)furfural (PvMF), HMF esters of valeric acid, isovaleric acid, caproic acid, isocaproic acid, 2-hexanoic acid, enanthic acid, 2-heptanoic acid, caprylic acid, 2-octanoic acid, pelargonic acid, 2-nonanoic acid, caproic acid 2-decanoic acid, acrylic acid, crotonic acid, 3- methylcrotonic acid, 2 -ethylbutyric acid, 3 -methylvaleric acid, sorbic acid, 2-ethylhexanoic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2,2-dimethylhexanoic acid, 2,2-dimethylheptanoic acid, 2,2- dimethyloctanoic acid,2,2-dimethylnonanoic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, malic acid, fumaric acid, maleic acid, pyruvic acid, fumaric acid, itaconic acid, adipic acid, suberic acid, azelaic sebacic acid, pimelic acid, methyl malonic acid, methyl succinic acid, methyl maleic acid, dimethyl maleic acid, methyl adipic acid, oleic acid or combinations thereof, preferably the esters of HMF is selected from 5- (acetoxymethyl)furfural (AcMF), 5-(formyloxymethyl)furfural (FMF), or 5-(propionyloxymethyl)furfural (PrMF).

3. The process as claimed in claim 1, wherein the XMF is 5- (chloromethyl)furfural (CMF).

4. The process as claimed in claim 1, wherein the biomass is obtained from macroalgae.

5. The process as claimed in claim 1, wherein the amount of biomass is in a weight range of 2 to 25%, with respect to the total weight of the reaction mixture.

6. The process as claimed in claim 4, wherein the macroalgae is selected from members of Rhodophyta, Chlorophyta, or Phaeophyta.

7. The process as claimed in claim 6, wherein the macroalgae is selected from species of Kappaphycus, Halymenia, Gigartina, Chondrus, Gelidium, Gracilaria, Porphyra, Eucheuma, Fucus, Laminaria, Sargassum, Solieria, Hypnea, Mastocarpus, Furcerllaria, Iridea, Anatheca, Meristotheca, Ahnfeltia, Gynmogongrus, Phyllophora, or Ulva, preferably the macroalgae is selected from Eucheuma cottonii, Eucheuma denticulatum (spinosum), Euchuema isiforme, Kappaphycus alvarezii, Kappaphycus striatus, Gracilaria fisheri, gracilaria dura, Gracilaria edulis, Gracilaria fisheri, Gracilaria gracilis, Gracilaria hainanensis, Gracilaria lemaneiformis, Gracilaria viridis, Halymenia durvillaea, Chondrus crispus, Solieria chordalis, Porphyra purpurea, Hypnea musciformis, Solieria filiformis, Mastocarpus stellatus, Mastocarpus papillatus, Porphyra capensis, Gelidium amansii, or combinations thereof.

8. The process as claimed in claim 1, wherein the solvent is aliphatic carboxylic acid selected from formic acid, acetic acid, propanoic acid, butanoic acid, valeric acid, isovaleric acid, caproic acid, isocaproic acid, 2- hexanoic acid, enanthic acid, 2-heptanoic acid, caprylic acid, 2-octanoic acid, pelargonic acid, 2-nonanoic acid, caproic acid 2-decanoic acid, acrylic acid, crotonic acid, 3-methylcrotonic acid, 2-ethylbutyric acid, 3- methylvaleric acid, sorbic acid, 2-ethylhexanoic acid, 2,2-dimethylbutanoic acid, 2,2-dimethylpentanoic acid, 2,2-dimethylhexanoic acid, 2,2- dimethylheptanoic acid, 2,2-dimethyloctanoic acid, 2,2-dimethylnonanoic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, malic acid, fumaric acid, maleic acid, pyruvic acid, fumaric acid, itaconic acid, adipic acid, suberic acid, azelaic sebacic acid, pimelic acid, methyl malonic acid, methyl succinic acid, methyl maleic acid, dimethyl maleic acid,methyl adipic acid, oleic acid, or combinations thereof, preferably acetic acid; and the amount of solvent is in a weight range of 70 to 97%, with respect to the total weight of the reaction mixture.

9. The process as claimed in claim 1, wherein the catalyst is selected from ion exchange resins, organic acids, inorganic acids, salts, Lewis acids, zeolites, clays, metal catalysts, enzymes, organic ammonium salts, or combinations thereof.

10. The process as claimed in claim 9, wherein the catalyst is an acidic ion exchange resin; and the amount of catalyst is in a weight range of 1 to 5%, with respect to the total weight of the reaction mixture.

11. The process as claimed in claim 1, further comprising purifying esters of HMF, and XMF from the mixture of esters of HMF, and XMF.

12. The process as claimed in claim 11, wherein the purification is carried out by a technique selected from filtration, centrifugation, distillation, solvent extraction, trituration, chromatographic techniques, adsorption, sublimation, re-crystallization, or combinations thereof.

13. The process as claimed in 1, wherein the process is carried out as a batch, semi-batch, or continuous process.

14. The process as claimed in claim 1, wherein the ester of HMF is AcMF, and the 5-(halomethyl)furfural is CMF, and the process further comprises oxidizing the mixture of AcMF and CMF to obtain 2,5-furan-dicarboxylic acid (FDCA).

15. The process as claimed in claim 14, wherein the yield of FDCA is in the range of 40 to 90%, with respect to the AcMF and CMF.

16. The process as claimed in claim 1, wherein the biomass is selected from unprocessed biomass, minimally processed biomass, processed biomass or combination thereof, having an acid insoluble matter of at least 2%, with respect to the total weight of biomass.

17. The process as claimed in claim 1, wherein the process captures at least 3% of carbon in the biomass into a mixture of esters of HMF, and XMF of which at least 1% of carbon is present as XMF.

18. The process as claimed in claim 1, wherein the mixture of esters of HMF, and XMF has a yield of at least 1.5 %, with respect to the total weight of the biomass on moisture free basis.

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