A reaction system and method for continuously preparing 5-hydroxymethylfurfural

Abstract

A reaction system and method for continuously preparing 5-hydroxymethylfurfural, the reaction system comprising a raw material tank, a reaction device, a phase separation extraction device, a vacuum distillation column and a product collection tank connected in sequence, the reaction device being connected with a catalyst storage tank and a catalyst recovery tank, the reaction device having a vertical cylinder shell, a flow guide cylinder being arranged in the cylinder shell in a vertical direction, and a gas distributor being arranged at the bottom of the cylinder shell and below the flow guide cylinder. The present application can realize the continuous preparation of 5-hydroxymethylfurfural, avoid the yield limitation of interval production of the kettle type reaction device, and is a technology with broad application prospect for realizing the continuous and large-scale production of biomass sugar and 5-HMF.

Description

Technical Field

[0001] This invention relates to the field of green renewable energy, specifically to a reaction system and method for the continuous preparation of 5-hydroxymethylfurfural. Background Technology

[0002] Biomass resources are abundant and widely distributed, forming a crucial part of future sustainable energy. Their rational development and full utilization can bring considerable economic benefits. Furthermore, their unique renewability and zero-carbon emissions provide a timely and feasible optimized path for achieving "dual-carbon" goals and sustainable circular economy development. 5-Hydroxymethylfurfural (HMF) is an important platform compound connecting biomass resources and petrochemicals. It can be converted into biofuels and numerous high-value-added chemicals (levulinic acid, 2,5-furandicarboxylic acid, γ-valerolactone, etc.). Its oxidation product, 2,5-furandicarboxylic acid (FDCA), is the most promising biomass-based alternative to petroleum-based terephthalic acid. Developing low-cost, scalable routes for 5-HMF production has become a research hotspot in the field of biomass catalytic conversion. The 5-HMF molecule contains highly reactive furan rings, aldehyde groups, and hydroxymethyl groups. In the reaction system, it readily undergoes hydration reactions to generate levulinic acid and formaldehyde. The insoluble humin formed through intermolecular polymerization can easily deactivate the catalyst. Constructing a catalytic conversion system that can suppress side reactions and enable timely and efficient product separation is key to achieving high-yield production of 5-HMF from biomass sugars. Developing highly active catalysts and novel reaction devices is central to the design of this efficient catalytic system. Numerous research papers and patents have reported on functional catalysts for the catalytic conversion of biomass sugars to 5-HMF. However, the use of batch-type reactors catalyzed by inorganic acids results in low reaction efficiency and generates significant amounts of acidic wastewater, severely hindering the industrial production of 5-HMF. Therefore, the development of continuous biomass sugar conversion and separation devices is essential for promoting the industrial production of 5-HMF.

[0003] Patent document CN202210518680.0 proposes a process in which solid acid is used as a catalyst to catalyze the conversion of biomass sugars in a batch reactor, followed by extraction, distillation, and other subsequent processes to achieve continuous preparation of 5-HMF. Chinese patent CN202211242346.3 proposes a multi-reactor combined process to convert cellulosic biomass into furfural and 5-HMF under the catalytic action of inorganic acid hydrolysis. Chinese patent CN201910289227.5 proposes a process using two reactors in series, employing inorganic acid as a catalyst for homogeneous catalysis of fructose syrup to prepare 5-HMF. While these reports can achieve continuous preparation of 5-HMF, they all suffer from the problem of lengthy and complex batch reactor systems. Summary of the Invention

[0004] The present invention aims to provide a reaction system and method for the continuous preparation of 5-hydroxymethylfurfural, thereby achieving the continuous preparation of 5-hydroxymethylfurfural.

[0005] To solve the above technical problems, the specific solution adopted by the present invention is as follows: a reaction system for continuous preparation of 5-hydroxymethylfurfural, comprising a raw material tank, a reaction device, a phase separation and extraction device, a vacuum distillation column and a product collection tank connected in sequence. The reaction device is connected to a catalyst storage tank and a catalyst recovery tank. The reaction device has a vertical cylindrical shell, in which a guide tube is provided along the vertical distribution. A gas distributor is provided at the bottom of the cylindrical shell and below the guide tube.

[0006] Preferably, the top of the vacuum distillation column is connected to the inlet of the solvent recovery tank, and the outlet of the solvent recovery tank is connected to the phase separation extraction device.

[0007] Preferably, the device further includes a first heat exchanger and a second heat exchanger. The cooling path of the first heat exchanger is connected between the reaction device and the phase separation extraction device, and the heating path of the first heat exchanger is connected between the raw material tank and the reaction device. The cooling path of the second heat exchanger is connected between the vacuum distillation column and the solvent recovery tank, and the heating path of the second heat exchanger is connected between the solvent recovery tank and the phase separation extraction device.

[0008] Preferably, a first pipeline mixer is provided on the pipeline from the aqueous phase component outlet of the raw material tank and the phase separation extraction device to the reaction device; a second pipeline mixer is provided on the pipeline from the upper outlet of the reaction device and the solvent outlet of the solvent recovery tank to the phase separation extraction device.

[0009] Preferably, a raw material booster pump is provided between the raw material tank and the reaction device; a water booster pump is provided between the aqueous phase component outlet of the phase separation extraction device and the reaction device; and a solvent booster pump is provided between the solvent recovery tank and the phase separation extraction device.

[0010] Preferably, the gas distributor is connected to the nitrogen tank via a gas pressurization pump.

[0011] Preferably, a nitrogen circulation pipeline is provided between the gas pressurization pump and the top of the reaction device.

[0012] Preferably, the catalyst recovery tank has a tank body and a transverse filter screen installed in the tube body. The top of the tank body is connected to the reaction device through an inlet pipe, and the bottom of the tube body is connected to the reaction device through a drain pipe. The catalyst in the reaction device can enter the tank body with the liquid phase through the inlet pipe and be collected on the transverse filter screen. The liquid phase can be discharged into the reaction device through the drain pipe.

[0013] Preferably, a water pump is installed on the inlet pipe; and a drain pump is installed on the outlet pipe.

[0014] Preferably, a liquid distributor is also provided in the shell, located on the outer periphery of the gas distributor and at the lower end of the guide tube. The liquid distributor is connected to the drain pipe and can spray liquid phase into the guide tube to increase the circulation velocity in the reaction device.

[0015] Preferably, the liquid distributor is annular, and the upper edge of the liquid distributor is provided with water distribution holes that are evenly spaced along its circumference.

[0016] Preferably, the connection point between the inlet pipe and the shell is located near the liquid distributor and the gas distributor.

[0017] Preferably, the shell and the guide tube are made of Hastelloy or zirconium-based material and are fitted with a polytetrafluoroethylene anti-corrosion lining.

[0018] Preferably, the phase separation extraction device has a built-in flow tube and guide vanes, an oil drain pipe fixed at the top, and a drain pipe fixed at the bottom.

[0019] Preferably, the vacuum distillation column has a multi-layer plate structure.

[0020] A method for the continuous preparation of 5-hydroxymethylfurfural, wherein the above-described reaction system is used to prepare 5-hydroxymethylfurfural.

[0021] Preferably, when the raw material conversion rate in the reaction device is less than 30%, the deactivated catalyst in the reaction device is recovered through a catalyst recovery tank, and then a new catalyst is added to the reaction device through a catalyst storage tank.

[0022] Preferably, the deactivated catalyst in the catalyst recovery tank is regenerated and then circulated back into the catalyst storage tank.

[0023] The reaction apparatus of this invention comprises a shell, a guide tube, and a gas distributor. Gas is continuously introduced into the guide tube through the gas distributor, causing the liquid phase in the guide tube to rise and fall between the guide tube and the shell, thereby achieving gas-lift internal circulation. The reaction products are continuously discharged from the top of the reaction apparatus. Combined with phase separation, continuous extraction, and distillation purification processes, and through flexible control of catalytic conversion and interphase mass transfer, the yield limitations of batch production in batch reactors are avoided. This is a technology with broad application prospects for realizing the continuous and large-scale production of 5-HMF from biomass sugars.

[0024] Compared with existing continuous 5-HMF preparation processes, the present invention has the following outstanding advantages:

[0025] The airlift internal circulation reactor provides ample catalyst phase contact surface for the catalytic conversion of biomass sugars. The uniform distribution and intense turbulence of microporous bubbles provide better mass transfer and heat control for the reaction system, reducing the generation of byproducts caused by localized heating.

[0026] A cyclone oil-water phase separator with an internal guide tube, combined with a pipeline mixer, can achieve effective extraction of organic phase products and efficient separation of reactants from the aqueous phase.

[0027] Catalyst and solvent recovery systems can significantly reduce system operating costs, and the proper use of heat exchange components can effectively save system energy consumption and improve equipment production efficiency. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the reaction system for the continuous preparation of 5-hydroxymethylfurfural according to the present invention;

[0029] Figure 2 for Figure 1 A schematic diagram of the reaction apparatus section;

[0030] Figure 3 for Figure 1 A schematic diagram of the phase separation and extraction device in the diagram;

[0031] Figure 4 for Figure 1 A schematic diagram of the vacuum distillation tower section in the diagram;

[0032] The diagram is labeled as follows: 1. Reaction apparatus; 101. Shell; 102. Flow guide tube; 2. Phase separation and extraction apparatus; 3. Vacuum distillation column; 4. Catalyst storage tank; 5. Catalyst recovery tank; 501. Tank body; 502. Horizontal filter screen; 6-1. First heat exchanger; 6-2. Second heat exchanger; 7. Raw material tank; 8. Product collection tank; 9. Solvent recovery tank; 10. First pipeline mixer; 11. Second pipeline mixer; 12-1. Raw material booster pump; 12-2. Water booster pump; 12-3. Gas pressurization and inlet pump; 12-4. Solvent booster pump; 12-5. Drain pump; 12-6. Priming pump; 13. Liquid distributor; 14. Gas distributor. Detailed Implementation

[0033] like Figure 1 As shown, the reaction system for the continuous preparation of 5-hydroxymethylfurfural according to the present invention mainly includes a reaction device 1, a phase separation and extraction device 2, a vacuum distillation column 3, a catalyst storage tank 4, a catalyst recovery tank 5, a first heat exchanger 6-1, a second heat exchanger 6-2, a raw material tank 7, a product collection tank 8, and a solvent recovery tank 9.

[0034] The cooling path of the first heat exchanger 6-1 is connected between the reaction device 1 and the phase separation extraction device 2, and the heating path of the first heat exchanger 6-1 is connected between the raw material tank 7 and the reaction device 1. The cooling path of the second heat exchanger 6-2 is connected between the vacuum distillation column 3 and the solvent recovery tank 9, and the heating path of the second heat exchanger 6-2 is connected between the solvent recovery tank 9 and the phase separation extraction device 2. Furthermore, a first pipeline mixer 10 is installed on the pipeline from the aqueous phase outlet of the raw material tank 7 and the phase separation extraction device 2 to the reaction device 1; a second pipeline mixer 11 is installed on the pipeline from the upper outlet of the reaction device 1 and the solvent outlet of the solvent recovery tank 9 to the phase separation extraction device 2. A raw material booster pump 12-1 is installed between the raw material tank 7 and the reaction device 1; a water booster pump 12-2 is installed between the aqueous phase outlet of the phase separation extraction device 2 and the reaction device 1; and a solvent booster pump 12-4 is installed between the solvent recovery tank 9 and the phase separation extraction device 2.

[0035] Combination Figure 1 and Figure 2 As shown, the reaction apparatus 1 has a circular shell 101 and a guide tube 102 and a gas distributor 14 disposed within the shell 101. The shell 101 and the guide tube 102 are made of Hastelloy or zirconium-based material and coated with a polytetrafluoroethylene liner to effectively prevent corrosion of the vessel walls. The gas distributor 14 is located at the bottom of the guide tube 102 and is connected to a nitrogen tank via a gas pressurization pump 12-3. During the reaction, nitrogen gas is sprayed upward from the gas distributor 14, providing nitrogen protection on one hand, and on the other hand, the thrust of the nitrogen gas rising along the guide tube 102 drives the material in the guide tube 102 upward in the direction shown in the figure. After the material reaches the top of the guide tube 102 and overflows, it falls under the influence of gravity, thereby realizing a gas-lift internal circulation in the reaction apparatus 1, allowing the reaction products to be continuously discharged from the top of the reaction apparatus 1. To save nitrogen, a nitrogen circulation pipeline is provided between the gas pressurization pump 12-3 and the top of the reaction device 1. After the nitrogen is discharged from the top of the reaction device 1, it is recycled back into the reaction device 1 through the nitrogen circulation pipeline and the gas distributor 14.

[0036] Both the catalyst storage tank 4 and the catalyst recovery tank 5 are connected to the shell 101 of the reaction apparatus 1 via pipelines. The catalyst recovery tank 5 has a tank body 501 and a transverse filter 502 installed in the pipe body. The top of the tank body 501 is connected to the reaction apparatus 1 via an inlet pipe and a water pump 12-6, and the bottom of the pipe body is connected to the reaction apparatus 1 via a drain pipe and a drain pump 12-5. The catalyst in the reaction apparatus 1 can enter the tank body 501 with the liquid phase through the inlet pipe and be collected on the transverse filter 502. The liquid phase can be discharged into the reaction apparatus 1 by the drain pump 12-5 through the drain pipe. In this embodiment, a liquid distributor 13 is connected after the pipe extends into the bottom of the shell 101. The liquid distributor 13 is annular and distributed around the outer periphery of the gas distributor 14 to avoid interference with the nitrogen circulation. Multiple spray holes are evenly spaced along the circumference of the liquid distributor 13, and the liquid distributor 13 is located at the bottom of the guide tube 102. This allows the material with the catalyst removed to be sprayed upward along the guide tube 102, further accelerating the upward flow velocity of the material in the guide tube 102 and further promoting the deceleration of the material between the guide tube 102 and the shell 101. This increases the internal circulation velocity in the reaction device 1, allowing the deactivated catalyst to enter the catalyst recovery tank 5 through the inlet pipe for catalyst recovery as soon as possible. After the catalyst is deactivated, the deactivated catalyst can be recovered more quickly and fresh catalyst can be added, thereby improving the production efficiency of the reaction device 1 and ensuring continuous reaction production.

[0037] Because the density of the catalyst used in the production reaction is usually greater than the density of the liquid phase inside the reaction device 1, it will deposit at the bottom of the reaction device 1 when there is no gas or liquid thrust. In the preferred embodiment of the present invention, the connection point between the inlet pipe and the shell 101 is located near the liquid distributor 13 and the gas distributor 14. Thus, during the deactivated catalyst recovery process, the upward thrust generated by the gas distributor 14 and the liquid distributor 13, and the small amount of material escaping from the guide tube 102, slows down the rate at which the catalyst descends. This causes the catalyst to slow down at the inlet pipe position, facilitating its entry into the catalyst recovery tank 5 through the inlet pipe, thereby further accelerating the recovery rate of the deactivated catalyst and further ensuring the production efficiency of the reaction device 1.

[0038] Combination Figure 1 and Figure 3 As shown, the phase separation extraction device 2 has a built-in flow-through cylinder and guide vanes, an oil drain pipe fixed at the top, and a drain pipe fixed at the bottom. (Refer to the figures...) Figure 4 As shown, the vacuum distillation column 3 has a multi-layer plate structure.

[0039] Based on the above structure, the present invention provides a continuous process for preparing 5-hydroxymethylfurfural as follows:

[0040] The raw material liquid stored in the raw material tank 7 is transported to the first heat exchanger 6-1 for preheating via the raw material booster pump 12-1 and then enters the reaction device 1. The solid acid catalyst is added to the reaction device 1 through the catalyst storage tank 4. The reaction system is protected by nitrogen. The nitrogen inside the reaction device 1 is injected into the reaction device 1 through the gas pressurization pump 12-3. After the gas is distributed in the reaction device 1 by the built-in gas distributor 14, a gas-liquid-solid multiphase fluidized state is formed. After the liquid-solid phase is circulated in the reaction device 1 by the built-in guide tube 102, the temperature rises and the reaction is started to complete the biomass sugar catalytic conversion to prepare 5-HMF. After the reaction liquid is discharged from the upper outlet of the reaction device 1, it enters the first heat exchanger 6-1 to exchange heat with the feed liquid and cool down. Then, it enters tangentially along the inner wall of the phase separation extraction device 2, where oil and water phases are separated under the swirling action of the built-in flow tube. The oil phase is discharged from the upper outlet of the phase separation extraction device 2 and enters the vacuum distillation tower 3. The low-boiling-point solvent is discharged from the upper part of the vacuum distillation tower 3, and after being cooled by heat exchange with the recycled solvent in the second heat exchanger 6-2, it enters the solvent recovery tank 9. The recovered solvent is transported to the second heat exchanger 6-2 for reheating by the solvent booster pump 12-4, and then thoroughly mixed with the reaction liquid discharge by the second pipeline mixer 11 before entering the phase separation extraction device 2 for oil and water phase separation. The aqueous phase component in the phase separation extraction device 2 is discharged from the bottom outlet of the tank, and after being thoroughly mixed with the preheated feed liquid by the first pipeline mixer 10 via the water booster pump 12-2, it enters the reaction device 1. The final product of the reaction system, 5-HMF, enters the product collection tank 8 through the bottom of the vacuum distillation tower 3. If the sugar conversion rate in reaction device 1 is less than 30%, the catalyst is considered deactivated. The deactivated catalyst is discharged from the bottom of reaction device 1 into catalyst recovery tank 5, and after regeneration, it enters catalyst storage tank 4 for reuse.

[0041] In a specific embodiment of the continuous production of 5-hydroxymethylfurfural of the present invention, an aqueous solution of biomass sugar (such as glucose, fructose, or high-fructose corn syrup) is mixed with an organic solvent (such as methyl isobutyl ketone (MIBK), methyl tert-butyl ether (MTBE), n-butanol, cyclopentyl methyl ether, ethyl acetate, etc., preferably MIBK) in a certain proportion to prepare a raw material solution of a certain concentration. The solution is pumped to the first heat exchanger 6-1 by the raw material booster pump 12-1 for preheating and then enters the reaction device 1. Using solid acid (sulfonated activated carbon) as a catalyst, under nitrogen protection at 0.1-3 MPa (preferably 2 MPa) and airlift internal circulation reaction conditions, the temperature is raised to 120°C and reacted for a certain time. The reaction solution is discharged through the upper outlet of the reaction device 1 and then enters the first heat exchanger 6-1 to exchange heat with the feed solution and cool down. It then enters the phase separation extraction device 2 tangentially along the inner wall of the phase separation extraction device 2, where it is subjected to swirling flow under the action of the built-in flow tube. Oil-water two-phase separation is performed. The less dense MIBK is discharged from the upper outlet of the phase separation extraction device 2 and enters the vacuum distillation tower 3. The low-boiling-point solvent MIBK is discharged from the upper part of the vacuum distillation tower 3, cooled by heat exchange with recycled solvent MIBK in the second heat exchanger 6-2, and then enters the solvent recovery tank 9. The recovered solvent MIBK is transported to the second heat exchanger 6-2 again by the solvent booster pump 12-4 for reheating, and then fully mixed with the reaction liquid outlet by the second pipeline mixer 11 before entering the phase separation extraction device 2 for oil-water two-phase separation. The aqueous phase component in the phase separation extraction device 2 is discharged from the bottom outlet of the tank, and fully mixed with the preheated feed liquid by the first pipeline mixer 10 via the water booster pump 12-2 before entering the reaction device 1. The final product of the reaction system, 5-HMF, enters the product collection tank 8 through the bottom of the vacuum distillation tower 3.

Claims

1. A reaction system for the continuous preparation of 5-hydroxymethylfurfural, characterized in that: The apparatus includes a raw material tank (7), a reaction device (1), a phase separation and extraction device (2), a vacuum distillation column (3), and a product collection tank (8) connected in sequence. The reaction device (1) is connected to a catalyst storage tank (4) and a catalyst recovery tank (5). The reaction device (1) has a vertical cylindrical shell (101). A guide tube (102) is provided in the cylindrical shell (101) and is distributed vertically. A gas distributor (14) is provided at the bottom of the cylindrical shell (101) and below the guide tube (102). The catalyst recovery tank (5) has a tank body (501) and a transverse filter screen (502) installed in the tube body. The top of the tank body (501) is connected to the reaction device (1) through a lead pipe, and the bottom of the tube body is connected to the reaction device (1) through a drain pipe. The catalyst in the reaction device (1) can enter the tank body (501) with the liquid phase through the lead pipe and be collected on the transverse filter screen (502). The liquid phase can be discharged into the reaction device (1) through the drain pipe. A liquid distributor (13) is also provided in the shell (101) at the position of the outer periphery of the gas distributor (14) and the lower end of the guide tube (102). The liquid distributor (13) is connected to the drain pipe and can spray liquid phase into the guide tube (102) to increase the circulation speed in the reaction device (1). The connection point between the inlet pipe and the shell (101) is located near the liquid distributor (13) and the gas distributor (14).

2. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The top of the vacuum distillation column (3) is connected to the inlet of the solvent recovery tank (9), and the outlet of the solvent recovery tank (9) is connected to the phase separation extraction device (2).

3. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 2, characterized in that: It also includes a first heat exchanger (6-1) and a second heat exchanger (6-2). The cooling path of the first heat exchanger (6-1) is connected between the reaction device (1) and the phase separation extraction device (2). The heating path of the first heat exchanger (6-1) is connected between the raw material tank (7) and the reaction device (1). The cooling path of the second heat exchanger (6-2) is connected between the vacuum distillation column (3) and the solvent recovery tank (9). The heating path of the second heat exchanger (6-2) is connected between the solvent recovery tank (9) and the phase separation extraction device (2).

4. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 2, characterized in that: A first pipeline mixer (10) is provided on the pipeline from the outlet of the aqueous phase component of the raw material tank (7) and the phase separation extraction device (2) to the reaction device (1); a second pipeline mixer (11) is provided on the pipeline from the upper outlet of the reaction device (1) and the solvent outlet of the solvent recovery tank (9) to the phase separation extraction device (2).

5. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: A raw material booster pump (12-1) is provided between the raw material tank (7) and the reaction device (1); a water booster pump (12-2) is provided between the aqueous phase component outlet of the phase separation extraction device (2) and the reaction device (1); and a solvent booster pump (12-4) is provided between the solvent recovery tank (9) and the phase separation extraction device (2).

6. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The gas distributor (14) is connected to the nitrogen tank via a gas pressurization pump (12-3).

7. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 6, characterized in that: A nitrogen circulation pipeline is provided between the gas pressurization pump (12-3) and the top of the reaction device (1).

8. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: A water inlet pump (12-6) is installed on the inlet pipe; a drain pump (12-5) is installed on the outlet pipe.

9. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The liquid distributor (13) is annular, and the upper edge of the liquid distributor (13) is provided with water distribution holes that are evenly spaced along its circumference.

10. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The shell (101) and the guide tube (102) are made of Hastelloy or zirconium-based material and are fitted with a polytetrafluoroethylene anti-corrosion lining.

11. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The phase separation extraction device (2) has a built-in flow tube and guide vanes, an oil drain pipe fixed at the top, and a drain pipe fixed at the bottom.

12. The reaction system for the continuous preparation of 5-hydroxymethylfurfural as described in claim 1, characterized in that: The vacuum distillation column (3) has a multi-layer plate structure.

13. A method for the continuous preparation of 5-hydroxymethylfurfural, characterized in that: 5-Hydroxymethylfurfural is prepared using any of the reaction systems for the continuous preparation of 5-hydroxymethylfurfural according to claims 1-12.

14. The method for continuous preparation of 5-hydroxymethylfurfural as described in claim 13, characterized in that: When the conversion rate of raw materials in the reaction device (1) is less than 30%, the deactivated catalyst in the reaction device (1) is recovered through the catalyst recovery tank (5), and then a new catalyst is added to the reaction device (1) through the catalyst storage tank (4).

15. The method for continuous preparation of 5-hydroxymethylfurfural as described in claim 14, characterized in that: The deactivated catalyst in the catalyst recovery tank (5) is regenerated and then circulated into the catalyst storage tank (4).

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