Efficient preparation system of hydroxymethyl lignin polyol

Abstract

The utility model relates to the technical field of extraction equipment, in particular to an efficient preparation system of hydroxymethyl lignin polyol, which comprises a crushing and stirring unit, a drying unit, an extraction and separation unit, an alkali reaction unit, a modification unit and a crystallization unit, the alkali reaction unit is used for dissolving lignin in the extracted and separated lignin solution into an alkaline solution, the modification unit is used for adding an acid solution into the lignin alkaline solution to enable the solution to be acidic and adding a catalyst to modify the lignin, and the crystallization unit is used for purifying separated hydroxymethyl lignin polyol. By arranging the crushing and stirring unit, the drying unit, the extraction and separation unit, the alkali reaction unit, the modification unit and the crystallization unit, hydroxymethyl lignin polyol extraction equipment is integrally arranged, so that the activity of lignin and the yield of participating in preparation of degradable polymers are greatly improved, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of extraction equipment, in particular to a high-efficiency preparation system of hydroxymethyl lignin polyol. Background Art

[0002] Lignin polyol is a mixture extracted from plant cell walls. It has good hydrophilicity due to the presence of multiple hydroxyl groups in its structure. As a natural polyphenol compound, lignin polyol has a variety of biological activities, including antioxidant, anti-inflammatory, antibacterial, anti-tumor, etc. It also exhibits high reactivity, which enables it to participate in reactions quickly and effectively when preparing various chemical products. Compared with other polyether polyols, the functionality of lignin polyol is highly adjustable, which provides greater flexibility in its application in chemical reactions and increases its application range in polyol mixtures.

[0003] The production and use of lignin polyols have little impact on the environment, which is in line with the current pursuit of green chemistry. Therefore, it has a wide range of uses: in the field of polyurethane, it is used to prepare two-component polyurethane paints, elastomers, sponge materials, etc.; in the field of epoxy resins, it participates in reactions and is used to produce epoxy resin coatings, adhesives, composite materials, etc.; in other fields: it is used for synthetic fibers, flame retardant materials, super adsorbents, medical materials, etc. However, traditional lignin polyols have poor chemical activity, and the yield of participating in the preparation of degradable polymers (such as polyesters, polyurethanes, polylactic acid copolymers, etc.) is as low as 60%, which has the defect of low yield, and the efficiency of preparing lignin polyols in the prior art is low. Utility Model Content

[0004] The technical problem to be solved by the utility model is: in order to overcome the defects of poor chemical activity of traditional lignin polyols in the prior art, a yield of 60% lower than that of participating in the preparation of degradable polymers (such as polyesters, polyurethanes, polylactic acid copolymers, etc.), and low yield, and the problem of low efficiency in preparing lignin polyols in the prior art, a high-efficiency preparation system of hydroxymethyl lignin polyols is provided.

[0005] The technical solution adopted by the utility model to solve the technical problem is: an efficient preparation system of hydroxymethyl lignin polyol, including a crushing and stirring unit, a drying unit, an extraction and separation unit, an alkali reaction unit, a modification unit and a crystallization unit.

[0006] The pulverizing and stirring unit is used for pulverizing the raw material containing lignin polyol;

[0007] The drying unit is used to dry the raw material containing lignin polyol after being crushed, and the input end of the drying unit is connected to the output end of the crushing and stirring unit;

[0008] The extraction and separation unit is used to extract and separate lignin from the dried raw material, and the input end of the extraction and separation unit is connected to the output end of the drying unit;

[0009] The alkali reaction unit is used to dissolve the lignin in the lignin solution separated by extraction into an alkaline solution, and the input end of the alkali reaction unit is connected to the output end of the extraction and separation unit;

[0010] The modification unit is used to add an acid solution to a lignin alkaline solution to make the solution acidic and add a catalyst to modify the lignin, and the input end of the modification unit is connected to the output end of the alkaline reaction unit;

[0011] The crystallization unit is used to purify the precipitated hydroxymethyl lignin polyol. The input end of the crystallization unit is connected to the output end of the modification unit. By arranging a crushing and stirring unit, a drying unit, an extraction and separation unit, an alkali reaction unit, a modification unit and a crystallization unit, the equipment for extracting the hydroxymethyl lignin polyol is integrated. The raw material straw for extracting the hydroxymethyl lignin polyol can be directly crushed to extract lignin, and the lignin is modified to prepare the hydroxymethyl lignin polyol. The hydroxymethyl lignin polyol extraction device solves the problem that the yield of participating in the preparation of degradable polymers (such as polyester, polyurethane, polylactic acid copolymer, etc.) is less than 60% due to the poor chemical activity of traditional lignin, greatly increases the activity of lignin and the yield of participating in the preparation of degradable polymers, improves production efficiency, increases its functionality, and the entire operation process is simple and convenient, reduces production costs, and increases corporate profits.

[0012] In order to solve the problem of how to arrange the crushing and mixing unit, the crushing and mixing unit further includes a crushing box, a horizontal screw conveyor, a vertical screw conveyor and a crusher. The horizontal screw conveyor is provided with a feeding hopper for supplying raw materials. The output end of the horizontal screw conveyor is connected with the input end of the vertical screw conveyor. The vertical screw conveyor extends into the crushing box. The crusher is arranged in the crushing box. The output end of the vertical screw conveyor faces the crusher. A crushing discharge port is provided on the crushing box.

[0013] In order to solve the problem of low lignin extraction efficiency caused by excessive residual moisture in the raw materials, the drying unit further includes a loading conveyor, a dryer and a feeding conveyor. The loading conveyor is used to transport the crushed raw materials to the feed end of the dryer, the output end of the loading conveyor is connected to the input end of the dryer, and the output end of the dryer is connected to the input end of the feeding conveyor. The dryer is used to dry the raw materials.

[0014] In order to solve the problem of low lignin extraction efficiency in raw materials, the extraction and separation unit further includes an extraction shell, an extraction heating mechanism and an extraction stirring mechanism. The extraction shell is provided with an extraction feed port, an extraction discharge port and a n-hexane addition port. The extraction heating mechanism is arranged on the outside of the extraction shell, and the extraction stirring mechanism is arranged inside the extraction shell. The extraction stirring mechanism is used to stir the solution in the extraction shell.

[0015] The invention further comprises an alkali reaction unit including a reaction shell, a reaction stirring mechanism, a dispersion plate and an air pump. A dissolved oxygen detector and a pH detector are installed on the reaction shell. An alkali reaction feed port, an alkali solution addition port, an alkali reaction discharge port and an exhaust port are provided on the alkali reaction shell. The dispersion plate and the reaction stirring mechanism are both arranged in the reaction shell. The dispersion plate is located below the reaction stirring mechanism. A plurality of air holes are provided on the dispersion plate. The air holes of the dispersion plate are connected to the output end of the air pump.

[0016] In order to solve the problem that the chemical activity of lignin polyol is poor and the yield of participating in the preparation of degradable polymers (such as polyester, polyurethane, polylactic acid copolymer, etc.) is as low as 60%, which has the defect of low yield, the modification unit further includes a modification shell, a modification stirring mechanism and a collecting bucket. The modification shell is provided with a modification feed inlet, a catalyst addition port, a modification steam outlet and a modification discharge port. The modification stirring mechanism and the collecting bucket are both arranged in the modification shell. The collecting bucket is arranged below the modification stirring mechanism. The output end of the collecting bucket is connected to the modification discharge port. The modification stirring mechanism is used to stir the solution in the modification shell.

[0017] The invention further comprises a crystallization unit including a crystallization shell, a heat exchanger, an elutriation column and a plurality of reflux mechanisms. The crystallization shell is provided with a crystallization feed port and a crystallization steam outlet. The first medium input end of the heat exchanger is connected to the lower part of the crystallization shell, the first medium output end of the heat exchanger is connected to the upper part of the crystallization shell, the input end of the elutriation column is connected to the output end of the crystallization shell, and the reflux mechanism is arranged in the crystallization shell, and the reflux mechanism is used to accelerate the upper and lower exchange of the solution in the crystallization shell.

[0018] The beneficial effects of the utility model are as follows: the utility model provides an efficient preparation system of hydroxymethyl lignin polyol, which integrates the equipment for extracting hydroxymethyl lignin polyol by setting a crushing and stirring unit, a drying unit, an extraction and separation unit, an alkali reaction unit, a modification unit and a crystallization unit, and can directly crush the raw material straw for extracting hydroxymethyl lignin polyol to extract lignin, and modify it to prepare hydroxymethyl lignin polyol;

[0019] The hydroxymethyl lignin polyol extraction device solves the problem that the yield of the preparation of degradable polymers (such as polyester, polyurethane, polylactic acid copolymer, etc.) is less than 60% due to the poor chemical activity of traditional lignin. It greatly increases the activity of lignin and the yield of the preparation of degradable polymers, improves production efficiency, and increases its functionality. The entire operation process is simple and convenient, reduces production costs, and increases corporate profits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 It is a structural schematic diagram of the utility model;

[0022] Figure 2 It is a structural schematic diagram of a crushing and stirring unit provided by the utility model;

[0023] Figure 3 It is a structural schematic diagram of a drying unit provided by the utility model;

[0024] Figure 4 It is a structural schematic diagram of the extraction and separation unit provided by the utility model;

[0025] Figure 5 It is a structural schematic diagram of the alkali reaction unit provided by the utility model;

[0026] Figure 6 It is a structural schematic diagram of the modification unit provided by the utility model;

[0027] Figure 7 It is a structural schematic diagram of a crystallization unit provided by the utility model.

[0028] In the figure: 1, crushing and mixing unit, 11, crushing box, 12, horizontal screw conveyor, 13, vertical screw conveyor, 14, crusher, 15, feed hopper;

[0029] 2. Drying unit, 21. Loading conveyor, 22. Drying machine, 23. Feeding conveyor;

[0030] 3. extraction and separation unit, 31. extraction shell, 311. extraction feed port, 312. extraction discharge port, 313. n-hexane addition port, 32. extraction heating mechanism, 33. extraction stirring mechanism;

[0031] 4. Alkali reaction unit, 41. reaction shell, 411. alkali reaction feed port, 412. alkali solution addition port, 413. alkali reaction discharge port, 414. exhaust port, 42. reaction stirring mechanism, 43. dispersion plate, 44. air pump, 45. dissolved oxygen detector, 46. pH detector;

[0032] 5. modification unit, 51. modification shell, 511. modification feed port, 512. catalyst adding port, 513. modification steam outlet, 514. modification discharge port, 52. modification stirring mechanism, 53. collection bucket;

[0033] 6. Crystallization unit, 61. Crystallization shell, 611. Crystallization feed inlet, 612. Crystallization steam outlet, 62. Heat exchanger, 63. Elutriation column, 64. Reflux mechanism. DETAILED DESCRIPTION

[0034] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0035] like Figure 1 The utility model is a schematic diagram of the structure of a high-efficiency preparation system of hydroxymethyl lignin polyol, comprising a crushing and stirring unit 1, a drying unit 2, an extraction and separation unit 3, an alkali reaction unit 4, a modification unit 5 and a crystallization unit 6.

[0036] like Figure 2 As shown, the pulverizing and stirring unit 1 is used to pulverize raw materials containing lignin polyols, and the raw materials containing lignin polyols include straw, wood chips, etc.; the pulverizing and stirring unit 1 includes a pulverizing box 11, a horizontal screw conveyor 12, a vertical screw conveyor 13 and a pulverizer 14, the horizontal screw conveyor 12 is provided with a feeding hopper 15 for feeding raw materials, the output end of the horizontal screw conveyor 12 is connected to the input end of the vertical screw conveyor 13, the horizontal screw conveyor 12 and the vertical screw conveyor 13 are used to transport raw materials, the vertical screw conveyor 13 extends into the pulverizing box 11, and the pulverizer 14 is arranged in the pulverizing box 11, the pulverizer 14 includes a pulverizing shaft, a pulverizing motor for driving the pulverizing shaft, and a pulverizing tool arranged on the pulverizing shaft, the output end of the vertical screw conveyor 13 faces the pulverizer 14, and a pulverizing discharge port is opened on the pulverizing box 11.

[0037] like Figure 3 As shown, the drying unit 2 is used to dry the raw material containing lignin polyol after crushing, and the input end of the drying unit 2 is connected to the output end of the crushing and mixing unit 1; the drying unit 2 includes a loading conveyor 21, a dryer 22 and a feeding conveyor 23, the loading conveyor 21 is used to transport the crushed raw material to the feeding end of the dryer 22, the output end of the loading conveyor 21 is connected to the input end of the dryer 22, the output end of the dryer 22 is connected to the input end of the feeding conveyor 23, the dryer 22 is used to dry the raw material, and the dryer 22 can be a drum dryer.

[0038] like Figure 4As shown, the extraction and separation unit 3 is used to extract and separate lignin from the dried raw material, and the input end of the extraction and separation unit 3 is connected to the output end of the drying unit 2; the extraction and separation unit 3 includes an extraction shell 31, an extraction heating mechanism 32 and an extraction stirring mechanism 33, the extraction shell 31 is provided with an extraction feed port 311, an extraction discharge port 312 and a n-hexane addition port 313, the extraction heating mechanism 32 is arranged on the outside of the extraction shell 31, the extraction stirring mechanism 33 is arranged in the extraction shell 31, the extraction stirring mechanism 33 is used to stir the solution in the extraction shell 31, and the extraction stirring mechanism 33 includes an extraction stirring shaft, an extraction stirring motor driving the extraction stirring shaft to rotate, and an extraction stirring paddle arranged on the extraction stirring shaft.

[0039] like Figure 5 As shown, the alkali reaction unit 4 is used to dissolve the lignin in the lignin solution extracted and separated into the alkaline solution, and the input end of the alkali reaction unit 4 is connected to the output end of the extraction and separation unit 3; the alkali reaction unit 4 includes a reaction shell 41, a reaction stirring mechanism 42, a dispersion disk 43 and an air pump 44, the reaction shell 41 is installed with a dissolved oxygen detector 45 and a pH detector 46, the alkali reaction shell 41 is provided with an alkali reaction feed port 411, an alkali solution addition port 412, an alkali reaction discharge port 413 and an exhaust port 414, the dispersion disk 43 and the reaction stirring mechanism 42 are both arranged in the reaction shell 41, the dispersion disk 43 is located below the reaction stirring mechanism 42, the dispersion disk 43 has a plurality of air holes, the air holes of the dispersion disk 43 are connected to the output end of the air pump 44, the dispersion disk 43 is used to disperse and output the gas into the solution, the reaction stirring mechanism 42 includes a reaction stirring shaft, a reaction stirring motor driving the reaction stirring shaft to rotate, and a reaction stirring paddle arranged on the reaction stirring shaft.

[0040] like Figure 6 As shown, the modification unit 5 is used to add an acid solution to an alkaline solution of lignin to make the solution acidic and add a catalyst to modify the lignin. The input end of the modification unit 5 is connected to the output end of the alkali reaction unit 4; the modification unit 5 includes a modification shell 51, a modification stirring mechanism 52 and a collecting bucket 53. The modification shell 51 has a modification feed inlet 511, a catalyst addition port 512, a modification steam outlet 513 and a modification discharge port 514. The modification stirring mechanism 52 and the collecting bucket 53 are both arranged in the modification shell 51, and the collecting bucket 53 is arranged below the modification stirring mechanism 52. The output end of the collecting bucket 53 is connected to the modification discharge port 514. The modification stirring mechanism 52 is used to stir the solution in the modification shell 51. The modification stirring mechanism 52 includes a modification stirring shaft, a modification stirring motor for driving the modification stirring shaft to rotate, and a modification stirring paddle arranged on the modification stirring shaft.

[0041] like Figure 7As shown, the crystallization unit 6 is used to purify the precipitated hydroxymethyl lignin polyol, and the input end of the crystallization unit 6 is connected to the output end of the modification unit 5; the crystallization unit 6 includes a crystallization shell 61, a heat exchanger 62, an elutriation column 63 and a plurality of reflux mechanisms 64, the crystallization shell 61 is provided with a crystallization feed port 611 and a crystallization steam outlet 612, the first medium input end of the heat exchanger 62 is connected to the lower part of the crystallization shell 61, the first medium output end of the heat exchanger 62 is connected to the upper part of the crystallization shell 61, the input end of the elutriation column 63 is connected to the output end of the crystallization shell 61, the reflux mechanism 64 is arranged in the crystallization shell 61, the reflux mechanism 64 is used to accelerate the upper and lower exchange of the solution in the crystallization shell 61, the elutriation column 63 is filled with strong cation exchange fillers such as amino groups, which have strong adsorption to organic matter and are suitable for preparing high-purity organic reagents.

[0042] By setting a crushing and stirring unit 1, a drying unit 2, an extraction and separation unit 3, an alkali reaction unit 4, a modification unit 5 and a crystallization unit 6, the equipment for extracting hydroxymethyl lignin polyol is integrated, and the raw material straw for extracting hydroxymethyl lignin polyol can be directly crushed to extract lignin, and the lignin can be modified to prepare hydroxymethyl lignin polyol;

[0043] The hydroxymethyl lignin polyol extraction device solves the problem that the yield of the preparation of degradable polymers (such as polyester, polyurethane, polylactic acid copolymer, etc.) is less than 60% due to the poor chemical activity of traditional lignin. It greatly increases the activity of lignin and the yield of the preparation of degradable polymers, improves production efficiency, and increases its functionality. The entire operation process is simple and convenient, reduces production costs, and increases corporate profits.

[0044] When using the high-efficiency extraction device of hydroxymethyl lignin polyol, first add the raw materials such as straw and wood chips to be used for extracting lignin polyol into the feed hopper 17 of the crushing and stirring unit 1, start the horizontal screw conveyor 12 and the vertical screw conveyor 13 to transport the raw materials into the crushing box 11, and after being crushed into wet materials by the crusher 14, transport them from the discharge port to the feeding conveyor 21 of the drying unit 2 and transport them to the dryer 22; start the dryer 22, and after being dried by the dryer 22, transport them to the extraction and separation unit 3 by the feeding conveyor 23; the dried straw dry material is introduced into the device from the extraction feed port 311, and 60% n-hexane is added to the n-hexane addition port 313. The content ratio of straw dry material to n-hexane is 1:3, the starting temperature of the extraction heating mechanism 31 is controlled at about 70°C, and the mixture is fully mixed after being stirred by the extraction stirring mechanism 33, and the extraction process is carried out. After the reaction is completed, the solution is layered, and the crude lignin is extracted and separated, placed on the upper layer of the solution, and flows out from the extraction outlet 312. In this process, the waste liquid is discharged until the crude lignin solution is seen, and then it is introduced into the alkali reaction unit 4; the solution enters the reaction shell 41 from the alkali reaction feed port 411 through a pipeline; the reaction shell 41 contains an alkaline solution, and due to the characteristic that lignin can be used in a strong alkaline solution, the lignin will dissolve in the added alkaline solution, and the reaction is started. The stirring mechanism 42 plays a stirring role, and the dissolved oxygen content and pH value are controlled by the dissolved oxygen detector 45 and the pH detector 46, so that the lignin in the solution is dissolved as much as possible in the added alkaline solution. It is worth noting that during the whole process, after the alkaline solution is added, the pH value of the liquid in the crushing device should not be greater than 10 to prevent cellulose from dissolving into the liquid; the air pump 44 is turned on to increase the mixing degree, and the alkali reaction discharge port 413 is opened to allow the lignin solution to flow out; the lignin solution enters the modification shell 51 from the modification feed port 511 through the pipeline, and a proper amount of acid is added to the modification shell 51 to change the pH value of the solution to the acidic solution, and the catalyst is added to the catalyst addition port 512. The hydroxymethyl lignin polyol solution is then flowed to the crystallization feed port 61 of the crystallization unit 6 via a pipeline, and the heater 62 is turned on to evaporate and crystallize it, thereby obtaining hydroxymethyl lignin polyol crystals, which are easier to store than the solution. In this process, the reflux mechanism 64 is turned on to block the heat exchange of the solution in the crystallization shell 61, and the solution evaporates and cools at the liquid surface to reach an oversaturated state, wherein part of the solute is deposited on the surface of the suspended particles to form crystals, and the crystals sink to the bottom and enter the elutriation column 63, and the crystallized product is discharged from the lower part of the elutriation column.

[0045] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An efficient preparation system of hydroxymethyl lignin polyol, characterized in that: It comprises a crushing and stirring unit (1), a drying unit (2), an extraction and separation unit (3), an alkali reaction unit (4), a modification unit (5) and a crystallization unit (6), The pulverizing and stirring unit (1) is used to pulverize the raw material containing lignin polyol; The drying unit (2) is used to dry the raw material containing lignin polyol after being crushed, and the input end of the drying unit (2) is connected to the output end of the crushing and stirring unit (1); The extraction and separation unit (3) is used to extract and separate lignin from the dried raw material, and the input end of the extraction and separation unit (3) is connected to the output end of the drying unit (2); The alkaline reaction unit (4) is used to dissolve the lignin in the lignin solution extracted and separated into an alkaline solution, and the input end of the alkaline reaction unit (4) is connected to the output end of the extraction and separation unit (3); The modification unit (5) is used to add an acid solution to a lignin alkaline solution to make the solution acidic and add a catalyst to modify the lignin, and the input end of the modification unit (5) is connected to the output end of the alkali reaction unit (4); The crystallization unit (6) is used to purify the precipitated hydroxymethyl lignin polyol, and the input end of the crystallization unit (6) is connected to the output end of the modification unit (5).

2. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The pulverizing and mixing unit (1) comprises a pulverizing box (11), a horizontal screw conveyor (12), a vertical screw conveyor (13) and a pulverizer (14); the horizontal screw conveyor (12) is provided with a feed hopper (15) for feeding raw materials; the output end of the horizontal screw conveyor (12) is connected to the input end of the vertical screw conveyor (13); the vertical screw conveyor (13) extends into the pulverizing box (11); the pulverizer (14) is arranged in the pulverizing box (11); the output end of the vertical screw conveyor (13) faces the pulverizer (14); and the pulverizing box (11) is provided with a pulverizing discharge port.

3. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The drying unit (2) comprises a loading conveyor (21), a drying machine (22) and a feeding conveyor (23); the loading conveyor (21) is used to transport the crushed raw materials to the feeding end of the drying machine (22); the output end of the loading conveyor (21) is connected to the input end of the drying machine (22); the output end of the drying machine (22) is connected to the input end of the feeding conveyor (23); and the drying machine (22) is used to dry the raw materials.

4. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The extraction separation unit (3) comprises an extraction shell (31), an extraction heating mechanism (32) and an extraction stirring mechanism (33); the extraction shell (31) is provided with an extraction feed port (311), an extraction discharge port (312) and an n-hexane addition port (313); the extraction heating mechanism (32) is arranged outside the extraction shell (31); the extraction stirring mechanism (33) is arranged inside the extraction shell (31); and the extraction stirring mechanism (33) is used to stir the solution in the extraction shell (31).

5. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The alkali reaction unit (4) comprises a reaction shell (41), a reaction stirring mechanism (42), a dispersion plate (43) and an air pump (44); a dissolved oxygen detector (45) and a pH detector (46) are installed on the reaction shell (41); an alkali reaction feed port (411), an alkali solution addition port (412), an alkali reaction discharge port (413) and an exhaust port (414) are provided on the reaction shell (41); the dispersion plate (43) and the reaction stirring mechanism (42) are both arranged in the reaction shell (41); the dispersion plate (43) is located below the reaction stirring mechanism (42); a plurality of air holes are provided on the dispersion plate (43); and the air holes of the dispersion plate (43) are connected to the output end of the air pump (44).

6. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The modification unit (5) comprises a modification shell (51), a modification stirring mechanism (52) and a collecting hopper (53); the modification shell (51) is provided with a modification feed port (511), a catalyst addition port (512), a modification steam outlet (513) and a modification outlet (514); the modification stirring mechanism (52) and the collecting hopper (53) are both arranged in the modification shell (51); the collecting hopper (53) is arranged below the modification stirring mechanism (52); the output end of the collecting hopper (53) is connected to the modification outlet (514); the modification stirring mechanism (52) is used for stirring the solution in the modification shell (51).

7. The efficient preparation system of hydroxymethyl lignin polyol according to claim 1, characterized in that: The crystallization unit (6) comprises a crystallization shell (61), a heat exchanger (62), an elutriation column (63) and a plurality of reflux mechanisms (64); the crystallization shell (61) is provided with a crystallization feed port (611) and a crystallization steam outlet (612); the first medium input end of the heat exchanger (62) is connected to the lower part of the crystallization shell (61); the first medium output end of the heat exchanger (62) is connected to the upper part of the crystallization shell (61); the input end of the elutriation column (63) is connected to the output end of the crystallization shell (61); the reflux mechanism (64) is arranged in the crystallization shell (61); and the reflux mechanism (64) is used to accelerate the upper and lower exchange of the solution in the crystallization shell (61).

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