An apparatus and method for continuous sugar dehydration to produce 5-hydroxymethylfurfural

Abstract

The application belongs to the technical field of catalytic chemistry and biomass resource utilization, and specifically discloses a device and method for continuously preparing 5-hydroxymethylfurfural through sugar dehydration, which comprises a storage tank, a raw material tank and a reaction mechanism, the surface of the storage tank is connected with a conveying pipe, the surface of the conveying pipe is provided with a first pump body for pumping the internal storage extractant of the storage tank into the reaction mechanism, the raw material is conveyed from top to bottom, and the extractant is conveyed from bottom to top, so that the downward raw material is in contact with the catalyst to generate 5-HMF through a dehydration reaction, the generated 5-HMF is immediately extracted into an organic phase by the upward extractant droplets, in-situ extraction greatly reduces the residence time of 5-HMF in the aqueous phase, effectively inhibits the side reaction, and the countercurrent operation maximizes the mass transfer efficiency, the method can effectively avoid the low production efficiency of the traditional reaction mode, the product in the organic phase is extracted from the aqueous phase to avoid excessive reaction, the product yield is improved, and the continuous process improves the product production efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalytic chemistry and biomass resource utilization, and specifically discloses a device and method for continuously preparing 5-hydroxymethylfurfural through sugar dehydration. BACKGROUND

[0002] 5-hydroxymethylfurfural (HMF) is an important intermediate compound connecting biomass and chemical raw materials, and can be used to synthesize a series of other furan derivatives with high added value, such as 2,5-furandicarboxylic acid and 2,5-tetrahydrofuran dimethanol, through hydrogenation, oxidation, etherification and esterification, and has great application prospect and value.

[0003] At present, the preparation methods of 5-hydroxymethylfurfural mainly include: (1) directly dehydrating fructose; (2) isomerizing glucose and then dehydrating; and (3) synthesizing 5-hydroxymethylfurfural after hydrolysis of cellulose, and mainly using a batch kettle for reaction to generate, which has low production efficiency and complicated operation.

[0004] Therefore, the technical personnel in the field propose a device and method for continuously preparing 5-hydroxymethylfurfural through sugar dehydration. SUMMARY

[0005] Therefore, the technical personnel in the field propose a device and method for continuously preparing 5-hydroxymethylfurfural through sugar dehydration.

[0006] To achieve the above purposes, the application provides a device and method for continuously preparing 5-hydroxymethylfurfural through sugar dehydration, which comprises a storage tank, a raw material tank and a reaction mechanism, the surface of the storage tank is communicated with a conveying pipe, the surface of the conveying pipe is provided with a first pump body for pumping the extraction agent stored in the storage tank into the reaction mechanism, the surface of the conveying pipe is communicated with a gas injection pipe, the surface of the raw material tank is communicated with a material conveying pipe, the surface of the material conveying pipe is provided with a second pump body for pumping the raw material in the raw material tank into the reaction mechanism, one side of the reaction mechanism is provided with a vacuum distillation column, the bottom of the vacuum distillation column is communicated with a product tank, the top of the vacuum distillation column is communicated with a recovery pipe, the surface of the vacuum distillation column is communicated with an output pipe, the other end of the output pipe is communicated with the reaction mechanism, one side of the vacuum distillation column is provided with an extraction agent recovery tank communicated with the other end of the recovery pipe, one side of the extraction agent recovery tank is provided with a third pump body for guiding the recovered extraction agent in the extraction agent recovery tank into the storage tank.

[0007] The raw material is fed from the raw material tank into the reaction mechanism from top to bottom, the extractant is fed from the storage tank into the reaction mechanism from bottom to top, the product formed in the reaction mechanism is fed into the vacuum distillation column for separation to obtain the extractant and the product 5-HMF, the extractant is stored in the extractant recovery tank and is pumped into the storage tank by the third pump body for reuse, and the product 5-HMF is stored in the product tank.

[0008] In the technical scheme, preferably, the reaction mechanism comprises a reaction kettle, a temporary storage kettle is arranged at the top of the reaction kettle, a discharge pipe is communicated with the top of the reaction kettle, the upper end of the discharge pipe is communicated with the temporary storage kettle, a waste liquid pipe is communicated with the bottom of the reaction kettle, a discharge pipe is communicated with the bottom of the temporary storage kettle, and an auxiliary assembly is arranged in the reaction kettle.

[0009] In the technical scheme, preferably, one end of the conveying pipe is communicated with the lower end of the surface of the reaction kettle, and one end of the feeding pipe is communicated with the upper end of the surface of the reaction kettle.

[0010] In the technical scheme, preferably, the auxiliary assembly comprises a plurality of tower plates, the plurality of tower plates are fixedly and uniformly connected to the inner wall of the reaction kettle from top to bottom, the center of each tower plate forms a passing area, a plurality of sieve holes are arranged on the surface of the passing area, and a reaction area is formed between two adjacent tower plates.

[0011] In the technical scheme, preferably, a flow guide pipe is communicated with the surface of the tower plate, the lower end of the flow guide pipe penetrates the tower plate and is communicated with the adjacent reaction area below, and the upper end of the flow guide pipe is flush with the top surface of the tower plate.

[0012] In the technical scheme, preferably, the flow guide pipes arranged on two adjacent tower plates are symmetrically arranged, a cofferdam is fixedly connected to the top of the tower plate, the cofferdam is in a circular ring shape, and the inner side of the cofferdam is communicated with the flow guide pipes.

[0013] In the technical scheme, preferably, a plurality of baffle plates are arranged on the top of the tower plate, both ends of each baffle plate are fixedly connected to the inner wall of the reaction kettle, and a plurality of through holes are arranged on the surface of each baffle plate.

[0014] A method for preparing 5-hydroxymethylfurfural by continuous dehydration of sugar, comprising the following method steps:

[0015] S1, the prepared sugar aqueous solution raw material is stored in the inside of the raw material tank, and the extractant is stored in the inside of the storage tank, the extractant and the raw material are pumped into the inside of the reaction mechanism by the first pump body and the second pump body;

[0016] S2, after the reaction is completed, the generated organic phase can be temporarily stored in the inside of the temporary storage kettle, and the final gravity sedimentation separation can be carried out at the same time, the separated organic extractant is discharged through the output pipe, the water phase is discharged through the discharge pipe, the product purity is improved, and the processing time of the subsequent vacuum distillation tower is reduced;

[0017] S3, the organic phase entering the inside of the vacuum distillation tower is separated by the vacuum distillation tower to obtain the extractant and the product, and the recovered extractant is pumped into the storage tank by the third pump body for recycling;

[0018] S4, the product is introduced into the inside of the product tank for storage, and the waste liquid and the water phase generated in the reaction process of the reaction mechanism are discharged separately.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. By conveying the raw material from top to bottom and the extractant from bottom to top, the downward raw material is contacted with the catalyst to generate 5-HMF by dehydration reaction, and the generated 5-HMF is immediately extracted into the organic phase by the rising extractant droplets, in-situ extraction greatly reduces the residence time of 5-HMF in the water phase, effectively inhibits the side reaction, and maximizes the mass transfer efficiency of the countercurrent operation. This kind of way can effectively avoid the low production efficiency of traditional reaction method, and avoid excessive reaction of the product extracted from the organic phase to the water phase, improve the product yield, and at the same time, the continuous process improves the product production efficiency.

[0021] 2. By setting the auxiliary assembly, the extractant is sheared into small droplets when passing through the screen hole, and naturally floats due to the smaller density than the water phase, and due to the setting of the cofferdam, the extractant is prevented from being driven by the raw material flow through the flow guide pipe into the inside of the lower reaction zone, and at the same time, the small droplets of the extractant are further sheared by the setting of the partition plate and the through hole, so that finer droplets can be formed to enhance the extraction effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present application;

[0023] Figure 2 It is a sectional view of the reaction mechanism of the present application;

[0024] Figure 3 It is a connection diagram of the tray and the reaction kettle of the present application;

[0025] Figure 4 It is a sectional view of the reaction kettle of the present application;

[0026] Figure 5 It is a distribution diagram of the partition plate and the tray of the present application;

[0027] Figure 6A flow chart of the present application;

[0028] Figure 7 A flow chart of the present application.

[0029] In the figure: 1, storage tank; 101, gas injection pipe; 102, conveying pipe; 103, first pump body; 2, raw material tank; 201, feed pipe; 202, second pump body; 3, reaction mechanism; 301, reaction kettle; 302, waste liquid pipe; 303, temporary storage kettle; 304, discharge pipe; 305, discharge pipe; 31, auxiliary assembly; 3101, tray; 3102, screen hole; 3103, flow guide pipe; 3104, partition; 3105, through hole; 3106, cofferdam; 4, output pipe; 5, vacuum distillation column; 501, product tank; 6, recovery pipe; 7, extractant recovery tank; 701, third pump body. DETAILED DESCRIPTION

[0030] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0031] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the present application is not limited to the specific embodiments disclosed below.

[0032] As Figures 1-7 shown in a kind of continuous sugar dehydration preparation 5-hydroxymethylfurfural device and method, including storage tank 1, raw material tank 2 and reaction mechanism 3, the surface of storage tank 1 is communicated with conveying pipe 102, the surface of conveying pipe 102 is provided with first pump body 103 for pumping the extractant in the inside of storage tank 1 into reaction mechanism 3, the surface of conveying pipe 102 is communicated with gas injection pipe 101, the surface of raw material tank 2 is communicated with feed pipe 201, the surface of feed pipe 201 is provided with second pump body 202 for pumping raw material in the inside of raw material tank 2 into reaction mechanism 3, one side of reaction mechanism 3 is provided with vacuum distillation column 5, the bottom of vacuum distillation column 5 is communicated with product tank 501, the top of vacuum distillation column 5 is communicated with recovery pipe 6, the surface of vacuum distillation column 5 is communicated with output pipe 4, the other end of output pipe 4 is communicated with reaction mechanism 3, one side of vacuum distillation column 5 is provided with extractant recovery tank 7 communicated with the other end of recovery pipe 6, one side of extractant recovery tank 7 is provided with third pump body 701 for guiding the extractant recovered in the inside of extractant recovery tank 7 into the inside of storage tank 1;

[0033] The raw materials are fed from the raw material tank 2 into the reaction mechanism 3 from top to bottom, and the extractant is fed from the storage tank 1 into the reaction mechanism 3 from bottom to top. The product formed in the reaction mechanism 3 is fed into the vacuum distillation tower 5 for separation to obtain the extractant and 5-HMF. The extractant is stored in the extractant recovery tank 7 and pumped into the storage tank 1 for reuse by the third pump body 701. The product 5-HMF is stored in the product tank 501.

[0034] The raw materials and the extractant are synchronously transported to the interior of the reaction mechanism 3 by the first pump body 103 and the second pump body 202 for reaction. The interior of the reactor 301 is filled with a catalyst. Specifically, the raw materials are glucose, fructose or fructose-glucose syrup as raw materials, and water is used as a solvent to prepare a sugar aqueous solution;

[0035] The extractant includes tetrahydrofuran, alkylphenol, n-butanol and dimethyl sulfoxide, etc., preferably tetrahydrofuran.

[0036] The product after treatment by the reaction mechanism 3 is introduced into the interior of the vacuum distillation tower 5 through the output pipe 4, and is separated by the vacuum distillation tower 5 to obtain the extractant and the product. The product is introduced into the interior of the product tank 501 for storage, and the recovered extractant can be pumped into the interior of the storage tank 1 for recycling.

[0037] like Figures 1-6 As shown, the reaction mechanism 3 includes a reactor 301, a temporary storage reactor 303 is provided on the top of the reactor 301, the top of the reactor 301 is connected to a discharge pipe 305, the upper end of the discharge pipe 305 is connected to the temporary storage reactor 303, the bottom of the reactor 301 is connected to a waste liquid pipe 302, the bottom of the temporary storage reactor 303 is connected to a discharge pipe 304, and an auxiliary component 31 is provided inside the reactor 301.

[0038] One end of the delivery pipe 102 is connected to the lower end of the surface of the reactor 301 , and one end of the material delivery pipe 201 is connected to the upper end of the surface of the reactor 301 .

[0039] The raw material is injected from the top of the reactor 301 downward through the feed pipe 201, while the extractant is injected from the bottom of the reactor 301 upward through the feed pipe 102 to react. After a period of equilibrium, the reaction maintains a state in which the upper layer is an organic layer containing the product and the lower layer is an aqueous layer. The upper organic layer containing the product can be introduced into the interior of the temporary tank 303 through the discharge pipe 305, thereby providing sufficient residence time and space for the organic layer, allowing the mixture discharged from the top of the reactor 301 (mainly the light organic extractant phase and the heavy aqueous phase) to undergo final gravity sedimentation separation. The further separated organic extractant is discharged separately through the output pipe 4, and the aqueous phase is discharged separately through the discharge pipe 304. This improves the purity of the product and reduces the subsequent processing time in the vacuum distillation column 5.

[0040] like Figures 1-6As shown, the auxiliary component 31 includes a plurality of tower plates 3101, which are evenly fixed to the inner wall of the reactor 301 from top to bottom. The center of the tower plate 3101 forms a passing zone, and the surface of the passing zone is provided with evenly distributed sieve holes 3102. A reaction zone is formed between two adjacent tower plates 3101.

[0041] The surface of the tower plate 3101 is connected to a draft tube 3103 , the lower end of the draft tube 3103 passes through the tower plate 3101 and is connected to the adjacent reaction zone below, and the upper end of the draft tube 3103 is flush with the top surface of the tower plate 3101 .

[0042] The flow guide pipes 3103 provided on two adjacent tower plates 3101 are symmetrically arranged, and a cofferdam 3106 is fixedly connected to the top of the tower plate 3101. The cofferdam 3106 is annular, and the inner side of the cofferdam 3106 is connected to the flow guide pipe 3103.

[0043] The top of the tower plate 3101 is provided with evenly distributed partitions 3104 . Both ends of the partitions 3104 are fixedly connected to the inner wall of the reactor 301 . Evenly distributed through holes 3105 are opened on the surface of the partitions 3104 .

[0044] Because the raw material is transported from top to bottom while the extractant is transported in the opposite direction, the descending raw material comes into contact with the catalyst, undergoing a dehydration reaction to produce 5-HMF. The generated 5-HMF is immediately extracted into the organic phase by the rising extractant droplets. This method effectively avoids the low production efficiency of traditional reaction methods. The organic phase extracts the product in the aqueous phase, avoiding overreaction and improving product yield. At the same time, the continuous process improves product production efficiency.

[0045] The downward raw material can be introduced into the interior of the reaction zone below through the draft tube 3103. Since the draft tubes 3103 provided on two adjacent trays 3101 are symmetrically arranged, the raw material can pass through the reaction zone and be introduced into the interior of the next reaction zone from the other draft tube 3103. The extractant can fully contact the raw material during its ascent through the sieve holes 3102, thereby extracting the generated 5-HMF. When the extractant passes through the sieve holes 3102, it is sheared into tiny droplets, which naturally float upward because their density is lower than that of the aqueous phase. The provision of the cofferdam 3106 can prevent the extractant from being carried by the raw material flow through the draft tube 3103 and discharged into the interior of the lower reaction zone. At the same time, the provision of the partition 3104 and the through hole 3105 can further shear the tiny droplets sheared by the extractant, so that they can form finer droplets to enhance the extraction effect.

[0046] A method for preparing 5-hydroxymethylfurfural by continuous sugar dehydration comprises the following steps:

[0047] S1, the prepared sugar solution raw material is stored in the inside of the raw material tank 2, and the extractant is stored in the inside of the storage tank 1, the extractant and the raw material are pumped into the inside of the reaction mechanism 3 through the first pump body 103 and the second pump body 202;

[0048] S2, after the reaction is completed, the generated organic phase can be temporarily stored in the inside of the temporary storage tank 303, and the final gravity sedimentation separation can be carried out at the same time, the separated organic extractant is discharged through the output pipe 4, the aqueous phase is discharged through the discharge pipe 304, the product purity is improved, and the processing time of the subsequent entering into the vacuum distillation column 5 is reduced;

[0049] S3, the organic phase entering into the inside of the vacuum distillation column 5 is separated through the vacuum distillation column 5 to obtain the extractant and the product, the recovered extractant is pumped into the storage tank 1 through the third pump body 701 and is recycled;

[0050] S4, the product is introduced into the inside of the product tank 501 and is stored, and the waste liquid and the aqueous phase generated in the reaction process of the reaction mechanism 3 are discharged separately.

[0051] The above shows and describes the basic principle, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application.

Claims

1. A device for continuously dehydrating sugar to prepare 5-hydroxymethylfurfural, comprising a storage tank (1), a raw material tank (2) and a reaction mechanism (3), characterized in that: The surface of the storage tank (1) is connected to a delivery pipe (102), and the surface of the delivery pipe (102) is provided with a first pump body (103) for pumping the extractant stored in the storage tank (1) into the reaction mechanism (3). The surface of the delivery pipe (102) is connected to a gas injection pipe (101). The surface of the raw material tank (2) is connected to a delivery pipe (201), and the surface of the delivery pipe (201) is provided with a second pump body (202) for pumping the raw material in the raw material tank (2) into the reaction mechanism (3). A vacuum distillation tower (5 ), the bottom of the vacuum distillation tower (5) is connected to a product tank (501), the top of the vacuum distillation tower (5) is connected to a recovery pipe (6), the surface of the vacuum distillation tower (5) is connected to an output pipe (4), the other end of the output pipe (4) is connected to the reaction mechanism (3), one side of the vacuum distillation tower (5) is provided with an extractant recovery tank (7) connected to the other end of the recovery pipe (6), and one side of the extractant recovery tank (7) is provided with a third pump body (701) for introducing the extractant recovered in the extractant recovery tank (7) into the storage tank (1); The raw materials are fed from the raw material tank (2) into the reaction mechanism (3) from top to bottom, the extractant is fed from the storage tank (1) into the reaction mechanism (3) from bottom to top, the product formed in the reaction mechanism (3) is fed into the vacuum distillation tower (5) for separation to obtain the extractant and the product 5-HMF, the extractant is stored in the extractant recovery tank (7) and pumped into the storage tank (1) for reuse through the third pump body (701), and the product 5-HMF is stored in the product tank (501); The reaction mechanism (3) comprises a reactor (301), a temporary storage reactor (303) is provided on the top of the reactor (301), the top of the reactor (301) is connected to a discharge pipe (305), the upper end of the discharge pipe (305) is connected to the temporary storage reactor (303), the bottom of the reactor (301) is connected to a waste liquid pipe (302), the bottom of the temporary storage reactor (303) is connected to a discharge pipe (304), and an auxiliary component (31) is provided inside the reactor (301); The auxiliary component (31) includes a plurality of trays (3101), wherein the plurality of trays (3101) are evenly fixedly connected to the inner wall of the reactor (301) from top to bottom, the center of the tray (3101) forms a passing zone, the surface of the passing zone is provided with evenly distributed sieve holes (3102), and a reaction zone is formed between two adjacent trays (3101); The surface of the tower plate (3101) is connected to a draft tube (3103), the lower end of the draft tube (3103) passes through the tower plate (3101) and is connected to the adjacent reaction zone below, and the upper end of the draft tube (3103) is flush with the top surface of the tower plate (3101); The flow guide pipes (3103) provided on two adjacent tower plates (3101) are symmetrically arranged, and a cofferdam (3106) is fixedly connected to the top of the tower plate (3101), the cofferdam (3106) is annular, and the inner side of the cofferdam (3106) is connected to the flow guide pipe (3103); A uniformly distributed partition (3104) is provided on the top of the tower plate (3101), both ends of the partition (3104) are fixedly connected to the inner wall of the reactor (301), and the surface of the partition (3104) is provided with uniformly distributed through holes (3105).

2. The device for preparing 5-hydroxymethylfurfural by continuous sugar dehydration according to claim 1, characterized in that: One end of the delivery pipe (102) is connected to the lower end of the surface of the reactor (301), and one end of the material delivery pipe (201) is connected to the upper end of the surface of the reactor (301).

3. A method for preparing 5-hydroxymethylfurfural by continuous sugar dehydration, applied to the apparatus for preparing 5-hydroxymethylfurfural by continuous sugar dehydration according to claim 2, characterized in that: The method comprises the following steps: S1, the prepared sugar aqueous solution raw material is stored in the raw material tank (2), and the extractant is stored in the storage tank (1), and the extractant and raw material are pumped into the reaction mechanism (3) through the first pump body (103) and the second pump body (202); S2. After the reaction is completed, the generated organic phase can be temporarily stored in the temporary storage kettle (303), and can be finally separated by gravity sedimentation. The separated organic extractant is discharged separately through the output pipe (4), and the aqueous phase is discharged separately through the discharge pipe (304), thereby improving the purity of the product and reducing the subsequent processing time of entering the vacuum distillation tower (5); S3, the organic phase entering the vacuum distillation tower (5) is separated into an extractant and a product by the vacuum distillation tower (5), and the recovered extractant is pumped into the storage tank (1) through the third pump body (701) for recycling; S4. The product is introduced into the internal storage of the product tank (501), while the waste liquid and the aqueous phase generated during the reaction process of the reaction mechanism (3) are discharged separately.

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