PROCESS FOR CONVERTING FRUCTOSE INTO

5-HYDROXYMETHYLFURFURAL USING A MESOPOROUS SILICA BASED CATALYST IMPREGNATED WITH RARE EARTH METALS

FIELD OF INVENTION

This invention related to method of producing 5-ydroxymethylfurfural (HMF) from fructose by using heterogeneous solid acid catalyst ICaT-2 without giving any considerable byproduct. This process is very economical as it involved high yield and simple separation process for the product. The use of the green solvents and heterogeneous ICaT-2 catalyst makes this process clean and sustainable. All the operations are carried out in batch reactor. The process is tolerance towards high fructose loading. The catalyst found to be very active without any substantial deactivation. The simplification in work-up, separation of product and very good recyclability of the catalyst make the process cost-effective and efficient. Isolation procedure for 5- hydroxymethyl furfural is also discussed.

BACKGROUND OF THE INVENTION

Chemicals derived from biomass feedstock are bringing the world on a sustainable platform. Carbohydrate feedstock has a remarkable opportunity to act as a future renewable biomass resource for substituting petroleum feedstock. 5- hydroxymethylfurfural (HMF) obtained from carbohydrate serve as a prospective building block.

5-hydroxymethylfurfural (HMF) produced from renewable resources act as platform chemical because of the wide range of the chemical intermediates and end products is produced from these compounds which used in the polymer industry, fuel and pharmaceutical industries. HMF possesses a high potential industrial demand, and is reviewed as a sleeping giant to produce intermediate chemical from bio based renewable resources. HMF is versatile chemical compound; however, no technical process has been constructed through sugar route till now. The reasons are low selectivity to HMF, requirement of strong acids, which requires neutralization and lead to large amount of acid waste. The high boiling polar solvents like dimethylsulfoxide, dimethylformamide, acetonitrile, poly(glycol ether) etc. give good selectivity to HMF but makes separation process most expensive. WO 012445A1 disclose a method of producing HMF by mixing or agitating an aqueous solution of fructose and inorganic acid catalyst with water immiscible organic solvent to form an emulsion. The mixture is heated to 240 °C to 270 °C in a flow reactor at high pressure and then separated into aqueous and organic phase to obtain HMF. US 313889A1 disclose the process for making hydroxymethylfurfural from saccharide. A metal complex of an N-heterocyclic carbine and ionic liquid is used. Reaction mixture contains solvent immiscible with ionic liquid to extract 5-hydroxymethylfurfural from ionic liquid. US 156841 Al disclose a method of producing substantially pure HMF, HMF esters and other derivatives from carbohydrate source. Carbohydrate solution containing organic acid is heated and continuously flowed through a solid phase catalyst to form HMF or/and HMF ester. US 033188A1 disclose the process for converting sugars to furan derivatives by using a biphasic reactor containing reactive aqueous phase and an organic extracting phase. The aqueous reaction solution contains an acid catalyst. Both aqueous solution and organic extraction solution contain at least one modifier such as dimethylsulfoxide, dimethylformamide, N-methylpyrrolidinone, acetonitrile, butyrolactone, dioxane and pyrrolidinone.

US 033187A1 disclose the process for converting carbohydrate to 5- hydroxymethylfurfural in the presence of metal halide and acid catalyst. In this process ionic liquids are used as solvent to dissolve carbohydrates. US 142599A1 disclose the process for preparation and purification of 5- hydroxymethyfurfural. In this process high fructose corn syrup is used as convenient fructose source and 5-hydroxymethylfurfural is prepared by using ion exchange resin in presence of 1 -methyl-2-pyrrolidinone, dimethylacetamide, dimethylformamide and combinations.

US 4590283A disclose the process for manufacturing 5-hydroxymethyfurfural from hexose by heterogeneous catalyst comprising of strong acid cation exchange resin. This process is carried out continuously, particularly by the countercurrent principle. Strongly polar aprotic solvent such as dimethylsulfoxide, dimethylformamide, N- methylpyrrolidone, are used, this makes product isolation tedious and costly.

According to the process in Green Chemistry 9 (2007) 342-350; 5-hydroxymethylfurfural is produce by dehydration of fructose and glucose using a biphasic reactor system, comprised of reactive aqueous phase modified with DMSO, combined with an organic extracting phase consisting of a 7:3 (w/w) MIBK-2-butanol mixture or dichloromethane by using mineral acid catalyst such as HC1, H ₂ S0 ₄ , H ₃ P0 ₄ .

According to the process in Journal of Molecular Catalysis A: Chemical 253 (2006) 165- 169; acid catalyzed dehydration of fructose and sucrose into 5-hydroxymethylfurfural is achieved in the presence of l-H-3 -methyl imidazolium chloride acting as both solvent and catalyst.

According to the process in Catalysis Communication 4 (2003) 517-520; dehydration of fructose into 5-hydroxymethylfurfural in presence of ionic liquid such as l-butyl-3- methyl imidazolium tetrafluroborate and l-butyl-3 -methyl imidazolium hexaflurophosphate as solvent and Amberlyst-15 as catalyst and DMSO as co-solvent was used. According to the process in the Journal of Molecular Catalysis A: Chemical 1 12 (1996) L163-L165; the relationship between the catalytic activity of lanthanoide (III) ions for dehydration of D-glucose to 5-hydroxymthyl furfural with the atomic number of the ions has been studied.

According to the process in Catalysis Communication 9 (2008) 2244-2249; production of 5-hydroxymethylfurfural from glucose and fructose by using Ti0 ₂ and Zr0 ₂ under microwave irradiation was studied. HMF yield was 38.1 % and fructose conversion was 83.6% for 5 min reaction time in presence of Ti0 ₂ catalyst was achieved. While HMF yield of 30.5% for fructose conversion of 65% was obtained for 5 min reaction time in presence of Zr0 ₂ . But these catalysts are suffered with poor reusability.

According to the process in Applied Catalysis A: General 275 (2004) 1 1 1-1 18; vanadyl phosphate was used as acid catalyst in the dehydration of fructose solution to afford 5- hydroxymethylfurfural . The dehydration of fructose to HMF was carried out by using mineral acids (such as HC1, H ₃ P0 ₄ , H ₂ S0 ₄ ), ion exchange resins, zeolites, transition metal ions and solid metal phosphates. Mineral acid catalysts are give high fructose conversion with low selectivity to HMF yield and major disadvantage is corrosion of reactor, separation of the product and large amount of acid waste. Solid acid catalysts, such as H-zeolite and metal phosphates (vanadyl phosphate) give low conversion and low selectivity. Several heterogeneous catalysts have been reported but these are also suffered with poor HMF yield and poor catalyst reusability.

This invention deals with to replace the mineral acid catalysts by stable, reusable, non- toxic solid acid catalyst. This invention discloses a method for producing 5- hydroxymethylfurfural from fructose by using reusable ICaT-2 catalyst. Reactions are carried out in batch reactor by using mixture of solvents. OBJECTIVE OF THE INVENTION

The objective of the present invention is to develop a process for production of 5- hydroxymethylfurfural from fructose with simplest reaction workup and with minimum production cost.

Another objective of the present invention is to develop process for production of 5- hydroxymethylfurfural which utilizes batch mode reactor or batch reactor system in series. Yet another objective of the present invention is to develop an improved method for 5- hydroxymethylfurfural production from fructose whereby drawbacks of prior art approaches are avoided and to get the easiest reaction procedure with maximum fructose concentration utilized in the reaction. Another objective of the present invention is to provide an environmentally safe and easy process for production of 5 -hydroxymethylfurfural from fructose at low cost to validate the possibility of its extrapolation to the chemical industry.

Another objective of the present invention is reacting feedstock solution comprising of fructose with the heterogeneous ICaT-2 catalyst by using mixed solvent system to yield 5 -hydroxymethylfurfural in good yield.

Yet another objective of the present invention is to use of cheaper and readily available biomass resources such as fructose to develop industrially feasible 5- hydroxymethylfurfural process.

Yet another objective of the present invention is to develop process for production of 5- hydroxymethylfurfural which utilizes mixture of various solvents to increase the product selectivity and reduces production cost by avoiding tedious reaction workup. Another objective of the present invention is to develop process for production of 5- hydroxymethylfurfural in which product is isolated in pure form by extraction and distillation. Another objective of the present invention is to utilize minimum quantity of heterogeneous reusable solid acid catalyst to produce 5-hydroxymethylfurfural from fructose.

Another objective of the present invention is to develop method for preparation of 5- hydroxymethylfurfural from fructose, which utilizes minimum energy and gives minimum waste.

SUMMARY OF INVENTION

The group of invention directed to a convenient method for production of 5- hydroxymethylfurfural (HMF) form renewable feedstock more precisely from fructose has been developed wherein fructose is dehydrated to 5-hydroxymethylfurfural by using ICaT-2 (Institute of Chemical Technology) catalyst in the presence of mixture of the solvents. Solvent selected from the group of water, methanol, ethanol, butanol, acetone, acetonitrile, dimethyl formamide, dimethyl sulfoxide and/or mixture thereof.

ICaT-2 catalyst is heterogeneous solid acid catalyst. It comprises of rare earth metal complex anchored with organic-inorganic porous silica as base metal through organic linkage. This process has been developed for batch mode operation. 5- hydroxymethylfurfural is isolated from reaction mass by extraction followed by distillation.

BRIEF DISCRIPTION OF DRAWINGS

Drawing 1 : Effect of catalyst loading

Drawing 2: Effect of fructose concentration

Drawing 3: Effect of temperature STATEMENT OF INVENTION

A present invention deals with the process for production of 5-hydroxymethylfurfural at substantial yield and purity from fructose in presence of heterogeneous mesoporous solid acid (ICaT-2) catalyst and mixed solvents system.

Process of invention comprises steps of

A) Mixing fructose with the mixture of solvents, up to limit of its solubility to form homogeneous solution.

B) Contacting homogeneous solution of fructose with heterogeneous mesoporous ICaT-2 catalyst at reaction temperature for particular reaction time to produce 5-hydroxymethylfurfural.

C) Filtrating and washing catalyst with organic solvent.

D) Isolating 5-hydroxymethylfurfural from product mixture of step A) to C) by a process selected from the group comprising of filtration, evaporation, extraction and distillation alone or in combination.

E) Distillation under reduced pressure to form pure 5-hydroxymethylfurfural product.

In the process, heterogeneous solid acid catalyst (ICaT-2) comprises of rare earth metal complex anchored with hexagonal organic-inorganic mesoporous silica through organic linkage.

Reaction of invention is performed in batch reactor or a batch reactor system in series for production of 5-hydroxymethylfurfural from fructose. Fructose solution are used in the range of 0.1% to 70% wt/wt, more preferably in the range of 1.0% to 50 % wt/wt of fructose solution and contacting of homogeneous solution of fructose with heterogeneous mesoporous ICaT-2 catalyst is done percentage in the range of 0.1 % to 50% wt wt percentage.

Solvent used in the process of invention is selected from the group of solvents such as water, methanol, ethanol, butanol, acetone, acetonitrile, dimethyl formamide, dimethyl sulfoxide, N-methyl pyrrolidone and/or mixture thereof and solvent can be preferably the mixture of water: methanol, water: ethanol, water: acetone and water: acetonitrile and/or mixture thereof. Water content in organic solvent is in the range of 1 to 90 %, more preferably in the range of 5 to 50 %.

The process of invention for production of 5-hydroxymethylfurfural from fructose, wherein reactions temperature is in the range. 50 °C to 300 °C, more preferably in the range of 80 °C to 250 °C and reaction time for contacting step is at least 10 hrs, more preferably in the range 1.0 min to 3 hrs.

Contacting of homogeneous solution of fructose with heterogeneous mesoporous ICaT-2 catalyst is carried out in the range of 1 bar to 30 bar, wherein pressure is autogeneous pressure or external pressure of the reaction.

The process for production of 5-hydroxymethylfurfural from fructose, wherein isolating pure 5-hydroxymethylfurfural from final reaction mixture is carried out by filtration, extraction with organic solvent such as ethyl acetate, diethyl ether, methyl isobutyl ketone, dichloromethane, methyl-tertiary-butyl ether, butyl acetate and/or mixture thereof; followed by vacuum distillation

DETAIL DESCRIPTION OF INVENTION

In accordance with the principle of the present invention process for preparation of a platform chemical, 5 -hydroxymethy furfural from renewable biomass such as from fructose has been developed, wherein fructose is reacted with ICaT-2 (Institute of Chemical Technology) catalyst to prepare 5-hydroxymethylfurfural (HMF) with high selectivity is described. ICaT-2 catalyst is comprises of rare earth metal complex anchored with organic-inorganic hexagonal porous silica as base metal through organic linkage. The present invention, utilizes heterogeneous ICaT-2 which is easily re-generable and shows excellent reusability for 5-hyroxymethylfurfural process. The ICaT-2 catalyst composition has specific surface area in the range of 50 m ² /g to 1000 m ² /g and pore diameter in the range of 20-100 A. In the present invention, fructose dehydration reaction is carried out under moderate conditions by using ICaT-2 as catalyst and mixture of solvents. 5 -hydroxymethylfurfural (HMF) produced from renewable resources act as platform chemical because of the wide range of the chemical intermediates and end products is produced from these compounds which used in the polymer industry, fuel and pharmaceutical industries. The reaction is shown as below:

Dehydration of Fructose to 5-hydoxymethylfurfural (HMF)

In the further accord with the present invention, fructose dehydration is carried out in batch mode operation by using an autoclave reactor. Reaction is agitated with four bladed pitch turbine impeller and temperature is maintained at +1°C of the desired value by PID controller.

One of the embodiments of the present invention for 5-hydroxymethylfurfural production method, wherein reactions are carried'out using heterogeneous ICaT-2 solid acid catalyst. It gives high efficiency for fructose conversion and excellent selectivity for 5- hydroxymethylfurfural. ICaT-2 catalyst is easily separable, regenerable, reusable and cost effective catalyst. In accord with the present invention for dehydration of fructose to 5- hydroxymethylfurfural process, wherein 1.0 % to 50 % wt/wt fructose is present to the reaction mixture. In accord with the present invention wherein fructose dehydration is carried out by using the solvent selected from the group of solvent such as water, methanol, ethanol, butanol, acetone, acetonitrile, dimethyl formamide, dimethyl sulfoxide and/or mixture thereof. In accord with the present invention for dehydration of fructose to 5- hydroxymethylfurfural process, wherein typically about 0.1 to 50% amount of the catalyst based on weight of the fructose are used in the reaction mixture. The used catalyst is recycled several times to check process feasibility for industrial utilization. The process of invention for 5-hydroxymethylfurfural production from fructose, wherein solvent used for reaction is the mixture of aqueous and organic solvent. Organic solvents used are such as methanol, ethanol, acetonitrile and acetone and/or mixture of thereof in the range of 1 to 90 %, more preferably in the range of 5 to 50 %. One of the embodiments of the present invention for dehydration of fructose to 5- hydroxymethylfurfural process, wherein reaction temperature is in the range of 50 °C to 300 °C, more preferably in the range of 50 °C to 250 °C are selected.

In accord with the present invention for dehydration of fructose to 5- hydroxymethylfurfural process is carried out for the time 1.0 min to 10 hours, more preferably for 1.0 min to 3 hours depending upon the type of solvent and amount of catalyst used.

One of the embodiments of the present invention is that the reaction is online monitor on HPLC by using RI detector and ultraviolet (UV) detector both.

In accord with the present invention is that product 5-hydroxymethylfurfural is separated from reaction mixture by extraction and simple distillation technique. A few of the numerous examples for the fructose dehydration to 5-hydroxymethylfurfural are considered as illustrative in terms of principles f the invention are listed below. EXAMPLE 1: Preparation of ICaT-2 catalyst

ICaT-2 is prepared by a co-condensation sol-gel route. Hexadecyl amine was dissolved in ethanol and water mixture. Mixture of tetraethyl orthosilicate and 3- (mercaptopropyl)trimethoxysilane were added to the above solution. It is treated with lanthanum chloride (400 mg) for 2 h. The slurry was filtered and treated with trifluromethanesulfonic acid (5.4 mmol) at 30 °C for 2 h. The slurry was filtered and washed with water and dried under vacuum to get the active ICaT-2 catalyst.

EXAMPLE 2-6:

All the reactions are carried out in batch mode operation. The reaction is performed by loading autoclave reactor with fructose (0.025 mol), 100 ml mixture of solvents (acetone and water 7:3) and specific amount of the ICaT-2 catalyst. The reactor is purged with nitrogen and temperature is raised to 160 °C. The experiments are carried out in a 300 cm stainless steel Parr autoclave. Reaction mixture is agitated with a four bladed pitch turbine impeller. The reaction temperature is maintained at 160 °C with an accuracy of + 1 °C by PID controller. Specific amount of ICaT-2 catalyst is added to reaction mixture (mentioned in Table 1). The effect of catalyst loading is studied with respect to variation in the quantity of catalyst (Drawing 1). The progress of the reaction is monitor on HPLC by using UV and RI detector. Calibration curve method is adopted for calculating percentage conversion and percentage yield quantitatively. Increase in catalyst loading results in higher conversion of fructose and HMF yield, due to a proportional increase in the number of active sites of the catalyst. After completion of the reaction, catalyst is filtered and washed with acetone. Extraction and distillation procedures are employed for isolation of 5-hydroxymethylfurfural from the reaction mixture.

EXAMPLE 7-11:

All the reactions are carried out in batch mode operation. The reaction is performed by loading autoclave reactor with fructose (0.025 mol), 100 ml mixture of solvents (7:3) and specific amount of the ICaT-2 catalyst (0.01 gm/cc). The reactor is purged with nitrogen and temperature is raised to 160 C. The experiments are carried out in a 300 cm stainless steel Parr autoclave. Reaction mixture is agitated with a four bladed pitch turbine impeller. The reaction temperature is maintained at 160 °C with an accuracy of + 1 °C by PID controller. The different mixture of solvents is used in these examples to evaluate the effect of solvent (mentioned in Table-2). The progress of the reaction is monitor on HPLC by using UV and RI detector. Calibration curve method is adopted for calculating percentage conversion and percentage yield quantitatively. After completion of the reaction, catalyst is filtered and washed with acetone. Extraction and distillation procedures are employed for isolation of 5-hydroxymethylfurfural from the reaction mixture.

'

EXAMPLE 12-16:

All the reactions are carried out in batch mode operation. The reaction is performed by loading autoclave reactor with fructose, 100 ml mixture of solvents (acetone :water 7:3) and specific amount of the ICaT-2 catalyst (0.01 gm/cc). The reactor is purged with nitrogen and temperature is raised to 160 °C. The experiments are carried out in a 300 cm stainless steel Parr autoclave. Reaction mixture is agitated with a four bladed pitch turbine impeller. The reaction temperature is maintained at 160 °C with an accuracy of + 1 °C by PID controller. Specific amount of fructose is added to reaction mixture (mentioned in Table-3). The progress of the reaction is monitor on HPLC by using UV and RI detector. Calibration curve method is adopted for calculating percentage conversion and percentage yield quantitatively. The different amount of fructose is used in these examples to evaluate its effect on conversion and yield (Drawing 2). After completion of the reaction, catalyst is filtered and washed with acetone. Extraction and distillation procedures are employed for isolation of 5-hydroxymethylfurfural from the reaction mixture.

EXAMPLE 17-20:

All the reactions are carried out in batch mode operation. The reaction is performed by loading autoclave reactor with fructose (0.025 mol), 100 ml mixture of solvents (acetone :water 7:3) and specific amount of the ICaT-2 catalyst (0.01 gm/cc). The reactor is purged with nitrogen and temperature is raised to desire value. The experiments are carried out in a 300 cm ³ stainless steel Parr autoclave. Reaction mixture is agitated with a four bladed pitch turbine impeller. The reaction temperature is maintained at desire value with an accuracy of + 1 °C by PID controller. The temperature of the reaction is varied in these examples (mentioned in Table-4). The progress of the reaction is monitor on HPLC by using UV and RI detector. Calibration curve method is adopted for calculating percentage conversion and percentage yield quantitatively. The effect of temperature in conversion and yield are shown in drawing 3. After completion of the reaction, catalyst is filtered and washed with acetone. Extraction and distillation procedures are employed for isolation of 5-hydroxymethylfurfural from the reaction mixture.

EXAMPLE 21-24:

All the reactions are carried out in batch mode operation. The reaction is performed by loading autoclave reactor with fructose (0.025 mol), 100 ml mixture of solvents (acetone rwater 7:3) and specific amount of the ICaT-2 catalyst (0.01 gm/cc). The reactor is purged with nitrogen and temperature is raised to 160 °C. The experiments are carried out in a 300 cm stainless steel Parr autoclave. Reaction mixture is agitated with a four bladed pitch turbine impeller. The reaction temperature is maintained at 160 °C with an accuracy of + 1 °C by PID controller. The progress of the reaction is monitor on HPLC by using UV and RI detector. Calibration curve method is adopted for calculating percentage conversion and percentage yield quantitatively. The reusability of the catalyst is tested by conducting four runs. After completion of the reaction, the catalyst is filtered and washed with acetone. Then it is refluxed with 50 cm ³ of acetone for 30 min and dried at 120 °C for 2 h. The reusability of the catalyst is mentioned in these examples (Table 5). Extraction and distillation procedures are employed for isolation of 5- hydroxymethylfurfural from the reaction mixture.

EXAMPLE 25:

The isolation and purification of 5-hydroxymethylfurfural is carried out by a process selected from the group consisting of filtration, evaporation, extraction and distillation. Reaction mass is filtered through filter paper to remove solid heterogeneous ICaT-2 catalyst. Catalyst was washed with 50 cm of acetone. Reaction mass is distilled under reduced pressure to remove acetone and then aqueous mother liquor is extracted with 100 X 3 times organic solvent such as ethyl acetate, diethylether, methyl isobutyl ketone, dichloromethane, methyl -tertiary-butyl ether, butyl acetate. Organic layer is dried by using sodium sulfate and distilled under reduced pressure to get pure 98 % HMF.