Method and system for removing acetal from dehydration reactions in a bdo purification process

Abstract

A method and system for removing acetals via dehydration reaction in BDO refining is disclosed. This method converts 1,4-butanediol to tetrahydrofuran via dehydration, recovers the tetrahydrofuran by distillation, and removes the acetal, thereby achieving acetal removal. Specifically, it includes the following steps: a. raw material vaporization; b. dehydration reaction; c. product distillation. Compared with existing methods for removing acetals via hydrogenation or dehydrogenation in 1,4-butanediol refining, this invention is more energy-efficient, has a simpler process flow, achieves a 1,4-butanediol conversion rate of over 98%, and a tetrahydrofuran selectivity of over 99%. It can effectively remove various acetals from BDO products and improve the economic efficiency of 1,4-butanediol production equipment.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and in particular to the production and refining of a chemical intermediate raw material, especially to a method and system for removing acetal through a dehydration reaction during the refining process of BDO. Background Technology

[0002] 1,4-Butanediol (BDO) and tetrahydrofuran (THF) are important organic and fine chemical raw materials, widely used in pharmaceuticals, chemicals, textiles, papermaking, automobiles, and daily chemical products. BDO can be used to produce tetrahydrofuran (THF), gamma-butyrolactone (GBL), polybutylene succinate (PBS), and polybutylene terephthalate (PBT), among others. THF can be used to produce polytetramethylene butylene glycol (PTMEG), a raw material for synthesizing high-elasticity spandex. Spandex is mainly used in the production of high-elasticity knitwear such as high-end sportswear and swimwear.

[0003] Currently, the main production methods for BDO include: the acetylacetonate method, the maleic anhydride method, the butadiene method, and the propylene oxide method. Domestic BDO producers primarily use the acetylacetonate and maleic anhydride methods. Regardless of the method used, various acetals are inevitably generated during BDO production. The acetylacetonate method produces hydroxybutyral and acetal, while the maleic anhydride esterification and hydrogenation method produces acetal 2-(4-hydroxybutoxy)tetrahydrofuran (HBTHF). These are impurities that are difficult to separate from BDO products. In particular, HBTHF forms an azeotrope with BDO, and ordinary distillation is insufficient to separate HBTHF from the BDO product. Often, the BDO in this azeotrope must be sacrificed to ensure the purity of the main BDO product meets standards.

[0004] CN1089744C provides a method for purifying a 1,4-butanediol feed containing a small amount of cyclic acetal 2-(4-hydroxybutoxy)-tetrahydrofuran. The method includes hydrogenating the 1,4-butanediol feed in a hydrogenation section in the presence of a small amount of water and a hydrogenation catalyst, and then recovering the 1,4-butanediol product from the hydrogenation section.

[0005] CN101052607B discloses a method for hydrogenating and purifying 1,4-butanediol, which converts acetal 2-(4-hydroxybutoxy)-tetrahydrofuran and / or its precursor into 1,4-butanediol under the action of a heterogeneous liquid copper catalyst, thereby obtaining a high-purity 1,4-butanediol product.

[0006] CN103796981B discloses a method for purifying 1,4-butanediol, which involves hydrogenating a crude 1,4-butanediol product containing 2-(4-hydroxybutoxy)-tetrahydrofuran and (4-hydroxybutyl)-4-hydroxybutyric acid in the presence of a hydrogenation catalyst, and recovering 1,4-butanediol from the hydrogenation zone.

[0007] CN103360206B discloses a method for producing 1,4-butanediol, tetrahydrofuran, γ-butyrolactone, and butanol. The method employs a diesterization reaction in an esterification unit using a fixed-bed reactor combined with a catalytic distillation column. After separating tetrahydrofuran from the reaction product, butanol is obtained through a butanol unit. The stream containing 1,4-butanediol and γ-butyrolactone is first partially separated from acetal along with 1,4-butanediol, thus obtaining a 1,4-butanediol product with the required purity. The 1,4-butanediol discharged along with the acetal is converted to γ-butyrolactone through a dehydrogenation reaction and then enters the γ-butyrolactone purification unit together with the acetal, achieving separation of the acetal and γ-butyrolactone.

[0008] CN107778141B discloses a purification method for 1,4-butanediol. The method includes: contacting crude 1,4-butanediol containing aldehyde compounds and / or acetal compounds as impurities with a silver-supported resin catalyst under hydrogen conditions to obtain purified 1,4-butanediol with a color intensity of less than 10 APHA.

[0009] CN114436778A discloses a method for purifying 1,4-butanediol by hydrogenation of acetal. The process involves simultaneously introducing water and hydrogen into crude 1,4-butanediol. After dissolving the hydrogen and water, the crude 1,4-butanediol is passed into a hydrogenation reactor for hydrogenation. The product is then distilled to obtain purified 1,4-butanediol.

[0010] The purification methods for 1,4-butanediol described in the aforementioned patent can be divided into two methods: hydrogenation and dehydrogenation. The hydrogenation method removes acetal by hydrogenating all crude BDO products containing HBTHF under specific hydrogenation catalysis, converting the acetal to BDO, followed by distillation to obtain BDO products of acceptable purity. The dehydrogenation method removes acetal by dehydrogenating a portion of the crude BDO product containing HBTHF to γ-butyrolactone under the action of hydrogenation and dehydrogenation catalysts, followed by purification of γ-butyrolactone to remove the acetal. The hydrogenation method requires hydrogenation of all crude BDO products in the production process, resulting in high energy consumption. The dehydrogenation method requires reaction under hydrogenation conditions, necessitating the use of a circulating hydrogen compressor, making the process more complex and the operating conditions more demanding. Summary of the Invention

[0011] The main objective of this application is to provide a method and system for removing acetals through dehydration reaction in the BDO refining process. The method involves using the azeotrope at the top of the BDO product column during 1,4-butanediol production to generate THF through a BDO dehydration reaction, followed by distillation to separate the acetal and recovery of the byproduct tetrahydrofuran. This invention features a short process flow, low energy consumption, and the ability to recover the more economically valuable THF product, thereby improving the economic efficiency of the 1,4-butanediol production plant.

[0012] To achieve the above objectives, in a first aspect, this application provides a method for removing acetal via dehydration reaction during BDO refining, comprising the following steps:

[0013] S1. The azeotrope at the top of the BDO product tower during the BDO production process is heat-exchanged and then enters the vaporizer for vaporization. The vaporized material is heated and then enters the dehydration reactor for reaction. The unvaporized material is pressurized by the dehydration vaporization circulation pump and then sent to the dehydration heater for heating. The heated material is returned to the vaporizer, and the unvaporized heavy components are sent to the waste liquid tank.

[0014] S2. The vaporized material enters from the top of the dehydration reactor and undergoes a dehydration reaction through the catalyst inside the dehydration reactor. The reaction products leave from the bottom of the dehydration reactor. The dehydration reaction includes a main dehydration reaction and a side dehydration reaction. The main dehydration reaction is the intramolecular dehydration of one molecule of BDO to generate one molecule of tetrahydrofuran and one molecule of water. The side dehydration reaction is the intermolecular dehydration of two molecules of BDO to generate one molecule of dibutylene glycol and one molecule of water.

[0015] S3. After the dehydration reaction, the reaction products are cooled by a heat exchanger and then enter the THF recovery tower. The gas phase at the top of the THF tower is condensed, and the non-condensable gas is sent to the incinerator for combustion. The condensate enters the THF recovery tower reflux tank. After being pressurized by the THF recovery tower reflux pump, part of the condensate is sent to the top of the THF recovery tower, and the other part is sent to the THF product refining unit for refining. The wastewater from the bottom of the THF recovery tower is sent to an external water treatment plant for water treatment.

[0016] A further improvement is that the wastewater from the bottom of the THF recovery tower is heated by steam in the THF recovery tower reboiler and then returned to the THF recovery tower.

[0017] A further improvement is that the catalyst is an Al2O3 catalyst.

[0018] A further improvement is that the catalyst is a magnesium-containing mesoporous γ-alumina dehydration catalyst.

[0019] A further improvement is that, in step S1, the operating pressure of the vaporizer is 0.1–0.5 MPa, the operating temperature is 150–250 °C, the water-to-alcohol mass ratio is 0.5–2, the temperature of the material after being heated by the dehydration heat exchanger is 200–240 °C, and the pressure of the saturated steam is 4.0–4.5 MPa.

[0020] A further improvement is that in step S2, during the dehydration reaction, the reaction temperature is 220–290℃, the reaction pressure is 0.1–0.5 MPa, and the mass hourly space velocity is 1–3.

[0021] A further improvement is that, in step S3, the THF recovery tower has a top pressure of 110–130 kPa, a top temperature of 40–80°C, a reflux ratio of 5–10, and a bottom temperature of 100–130°C.

[0022] A further improvement is that the acetal includes 2-(4-hydroxybutoxy)tetrahydrofuran.

[0023] At least one of hydroxybutyraldehyde and acetal. The crude 1,4-butanediol raw material containing acetal accounts for 1-10% of the BDO product in the BDO production process, and the acetal content in the crude 1,4-butanediol raw material is 0.1%-5% by mass.

[0024] To achieve the above objectives, in a second aspect, this application provides a system for removing acetals through a dehydration reaction in the BDO refining process, including a vaporization and dehydration component and a product distillation component.

[0025] The vaporization and dehydration assembly includes a vaporizer, a dehydration feed preheater connected to the top of the vaporizer, a dehydration reactor connected to the top of the dehydration feed preheater, and a dehydration heat exchanger connected to the bottom of the dehydration reactor. The dehydration heat exchanger is connected to a raw material inlet. The vaporizer is connected to a steam interface. The bottom of the vaporizer is connected to a dehydration vaporizer circulation pump. The dehydration vaporizer circulation pump is connected to a dehydration heater and a waste liquid tank. The dehydration heater is connected to the vaporizer.

[0026] The product distillation assembly includes a THF recovery tower, a THF recovery tower condenser connected to the top of the THF recovery tower, a THF recovery tower reflux tank connected to the THF recovery tower condenser, an incinerator connected to the THF recovery tower condenser and the THF recovery tower reflux tank, a THF recovery tower reflux pump connected to the THF recovery tower reflux tank, a THF recovery tower bottom pump connected to the bottom of the THF recovery tower, an external water treatment device connected to the THF recovery tower, and the THF recovery tower reflux pump connected to both the THF recovery tower and the refining unit.

[0027] A further improvement is that the bottom of the THF recovery tower is connected to a THF recovery tower reboiler.

[0028] A further improvement is that the steam interface is connected to the steam pipeline network.

[0029] A further improvement is that the dehydration reactor includes a shell and a series of tubes disposed within the shell, with heat transfer oil disposed in the cavity of the shell and a catalyst disposed within the series of tubes.

[0030] A further improvement is that the THF recovery tower is a plate distillation tower with a theoretical number of 10 to 30 plates.

[0031] A further improvement is that the vaporizer is equipped with metal Pall ring packing, with a theoretical number of 5 to 10 plates.

[0032] The present invention provides a method and system for removing acetals through dehydration reaction in the BDO refining process. Compared with the prior art, its advantages are as follows:

[0033] 1. The present invention provides a method for removing acetals through dehydration reaction in the production of 1,4-butanediol. The conversion rate of BDO is above 98%, the selectivity of THF is above 99%, and the crude THF recovered by distillation is basically free of acetals and other byproducts. Furthermore, the output ratio of byproduct THF in the 1,4-butanediol unit can be adjusted by appropriately adjusting the feed rate to meet market demand.

[0034] 2. Compared with the hydrogenation acetal removal process, the present invention only requires the dehydration of the azeotropic crude product at the top of the BDO product tower, instead of processing all the crude BDO products. This not only simplifies the process and reduces equipment investment, but also reduces operating costs. The BDO dehydration reaction products have a simple composition and are easy to separate, which also reduces separation energy consumption. This allows the method of the present invention to significantly reduce the production cost of 1,4-butanediol.

[0035] 3. Compared with the dehydrogenation and acetal removal process, the present invention does not require hydrogen-containing reaction conditions, the reaction conditions are simpler, the catalyst life is longer, the separation is simpler, and all equipment in the process of the present invention can be made of carbon steel, resulting in lower investment costs. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0037] Figure 1 This is a system flowchart of the present invention;

[0038] Figure 2 This is the flow chart of the BDO refining unit.

[0039] The components are as follows: V-101, vaporizer; E-101, dehydration heater; E-102, dehydration feed preheater; R-101, dehydration reactor; E-103, dehydration heat exchanger; T-101, THF recovery tower; E-104, THF recovery tower condenser; V-102, THF recovery tower reflux tank; E-105, THF recovery tower reboiler; P-101, dehydration vaporizer circulating pump; P-102, THF recovery tower bottom pump; P-103, THF recovery tower reflux pump; T-3430, BDO product tower; E-3431, BDO product tower condenser. Equipment; E-3432, BDO product column subcooler; E-3430, BDO product column reboiler; E-3433, BDO product column water cooler; V-3433, BDO product column reflux tank; E-3441, BDO product condenser; E-3442, BDO product cooler; P-3433A / B, BDO product column vacuum pump; P-3430A / B, BDO product column bottom pump; P-3431A / B, BDO product column reflux pump; P-3432A / B, BDO product column side-stream pump; V-3510, BDO dehydration feed tank. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0043] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0044] In addition, the term "multiple" should mean two or more.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] The formation process of azeotrope 1 at the top of the BDO product column is as follows: Figure 2 As shown, crude 1,4-butanediol is pumped from the bottom of the GBL recovery tower to the BDO product tower T-3430. The BDO product tower T-3430 is a vacuum packed tower. The overhead stream from the BDO product tower is partially condensed in the BDO product tower condenser E-3431 (simultaneously producing low-pressure steam as a byproduct), and then cooled in the BDO product tower subcooler E-3432. The overhead product is separated in the BDO product tower reflux tank V-3433. The condensate is pressurized by the BDO product tower reflux pump P-3431A / B and divided into two parts. One part of the condensate is returned to the tower, and the other part is cooled by the BDO product tower water cooler E-3433 and further divided into two parts, returning to the BDO product tower reflux tank V-3433 to remove uncondensed gas from the BDO collection tank and the 1,4-butanediol (BDO) tower reflux tank. The remaining BDO product tower condensate is sent to the BDO dehydration feed tank V-3510. This part is the azeotrope of BDO and acetal HBTHF, which needs to be dehydrated to ensure that the BDO product produced from the side stream meets the standards. Otherwise, the purity of the BDO product will be reduced, resulting in unqualified products.

[0047] The BDO product tower reboiler E-3430 is heated by medium-pressure steam, and the heavy components at the bottom of the tower are sent back to the GBL recovery tower by the BDO product tower bottom pump P-3430A / B.

[0048] BDO product is drawn out by the BDO product tower side-line sampling pump P-3432A / B, condensed by the BDO product condenser E-3441 (simultaneously producing low-pressure steam as a byproduct), and then pumped to the BDO product testing tank in the intermediate tank area by the BDO product cooler E-3442.

[0049] The BDO product column has two functions: first, to remove azeotropic substances from the top of the column; and second, to remove heavy components from the bottom of the column. The heavy component is dibutanediol, CAS No. 3403-82-5 (4,4'-oxybis(but-1-ol)).

[0050] The following are specific embodiments of the treatment of the azeotrope of BDO and acetal HBTHF in this application.

[0051] Example 1

[0052] a. According to the appendix Figure 1 As shown, the 750 kg / h BDO product azeotrope 1 from the top of the column is heated to 240°C by the dehydration heat exchanger E-103 and then fed into the top of the vaporizer V101. 4.0 MPaG steam 2 from the steam network is fed into the bottom of the vaporizer V101. The BDO azeotrope feedstock is vaporized in the vaporizer V101, and the top vapor phase 5 is heated to 280°C by the dehydration feed preheater E-102 before entering the dehydration reactor R-101. The bottom material of the vaporizer is extracted by the dehydration vaporizer circulation pump P-101, from which a small portion 4 (heavy components) is separated and sent to the waste tank, while the remaining 3 is heated to 240°C by the dehydration heater E-101 and then returned to the vaporizer.

[0053] The operating pressure of vaporizer V101 is 0.05 MPaG, the operating temperature at the top of the vaporizer is 185℃, and the operating temperature at the bottom of the vaporizer is 236℃. The steam to feed mass ratio is 1.

[0054] b. As per attachment Figure 1 As shown, in dehydration reactor R-101, BDO undergoes a dehydration reaction to produce THF and water. The reaction temperature is 280℃, the reaction pressure is 0.04 MPaG, the water-to-ethanol mass ratio is 1, and the mass hourly space velocity (HHSV) is 2. The catalyst used is Al₂O₃. The dehydration reactor employs a shell-and-tube heat exchanger structure. The tube side contains the catalyst and the reactants pass through it. The shell side uses 300℃ high-temperature heat transfer oil to heat the tube-side material, providing the heat required for the reaction. The gaseous feedstock enters from the top of the reactor, passes through the tubes, and undergoes a dehydration reaction under the action of the catalyst to produce THF and water, which exit from the bottom of the reactor.

[0055] The dehydration reaction is exothermic. The dehydrated product 6 is cooled to 145°C by the dehydration heat exchanger E-103 and then directly enters the THF recovery tower.

[0056] c. As per attachment Figure 1 As shown, the THF recovery tower is a plate tower, and the reboiler E-105 is heated by steam. The top vapor phase 7 is condensed to 60°C in the THF recovery tower condenser E-104, and the non-condensable gas 8 is sent to the incinerator for combustion. The condensate enters the THF recovery tower reflux tank V-102, and after being pressurized by the THF recovery tower reflux pump, it is divided into two parts: one part 9 is refluxed back to the top of the THF recovery tower, and the other part 10 is sent as crude THF product to the THF product refining unit. The THF recovery tower bottom wastewater 11 is pressurized by the THF recovery tower bottom pump and sent to an external water treatment plant.

[0057] The analysis results of the raw materials and products in this embodiment are shown in Table 1.

[0058] Table 1

[0059]

[0060] As shown in Table 1, under the conditions of Example 1, the conversion rate of BDO was 99.93% and the THF selectivity was 99.43%.

[0061] Example 2

[0062] The implementation process is the same as in Example 1, except that the conditions for the BDO dehydration reaction are changed: the reaction temperature is 280°C, the reaction pressure is 0.04 MPaG, the water-to-alcohol mass ratio is 0.5, and the mass hourly space velocity (HHSV) is 2. All other conditions and procedures are the same as in Example 1.

[0063] The analysis results of the raw materials and products in this embodiment are shown in Table 2.

[0064] Table 2

[0065]

[0066] As shown in Table 2, under the conditions of Example 2, the conversion rate of BDO was 99.69%, and the THF selectivity was 99.34%.

[0067] Example 3

[0068] The implementation process is the same as in Example 1, except that the conditions for the BDO dehydration reaction are changed: the reaction temperature is 250°C, the reaction pressure is 0.04 MPaG, the water-to-alcohol mass ratio is 1, and the mass hourly space velocity (HHSV) is 2. All other conditions and procedures are the same as in Example 1.

[0069] The analysis results of the raw materials and products in this embodiment are shown in Table 3.

[0070] Table 3

[0071]

[0072] As shown in Table 3, under the conditions of Example 3, the conversion rate of BDO was 98.32%, and the THF selectivity was 99.18%.

[0073] Comparing the results of Examples 1-3, as the reaction temperature for the dehydration of 1,4-butanediol increased and the mass ratio of water to alcohol increased, the conversion rate of 1,4-butanediol gradually increased, the selectivity of tetrahydrofuran remained above 99%, and there was no acetal in the crude THF product, so the acetal could be completely removed.

[0074] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for removing acetal via dehydration reaction during BDO refining, characterized in that, Includes the following steps: S1. The azeotrope at the top of the BDO product tower during the BDO production process is vaporized after heat exchange in a vaporizer. The vaporized material is heated and then fed into a dehydration reactor for reaction. The unvaporized material is pressurized by a dehydration vaporization circulation pump and then sent to a dehydration heater for heating. The heated material is returned to the vaporizer. The unvaporized heavy components are sent to a waste liquid tank. The operating pressure of the vaporizer is 0.1-0.5 MPa, the operating temperature is 150-250°C, the water-to-alcohol mass ratio is 0.5-2, the temperature of the material after heating in the dehydration heat exchanger is 200-240°C, and the pressure of the saturated steam is 4.0-4.5 MPa. S2. The vaporized material enters from the top of the dehydration reactor and undergoes a dehydration reaction through the catalyst inside the reactor. The reaction products exit from the bottom of the dehydration reactor. The dehydration reaction includes a main dehydration reaction and a side dehydration reaction. The main dehydration reaction is the intramolecular dehydration of one molecule of BDO to produce one molecule of tetrahydrofuran and one molecule of water. The side dehydration reaction is the intermolecular dehydration of two molecules of BDO to produce one molecule of dibutyl ether glycol and one molecule of water. The catalyst is an Al2O3 catalyst. In the dehydration reaction, the reaction temperature is 220-290℃, the reaction pressure is 0.1-0.5 MPa, and the mass hourly space velocity is 1-3. S3. The reaction products after dehydration reaction are cooled by a heat exchanger and then enter the THF recovery tower. The gas phase at the top of the THF tower is condensed, and the non-condensable gas is sent to the incinerator for combustion. The condensate enters the reflux tank of the THF recovery tower. After being pressurized by the reflux pump of the THF recovery tower, part of the condensate is sent to the top of the THF recovery tower, and the other part of the condensate is sent to the THF product refining unit for refining. The wastewater from the bottom of the THF recovery tower is sent to an external water treatment device for water treatment. The pressure at the top of the THF recovery tower is 110-130 kPa, the temperature at the top of the tower is 40-80°C, the reflux ratio is 5-10, and the temperature at the bottom of the tower is 100-130°C.

2. The method for removing acetal through dehydration reaction in the BDO refining process as described in claim 1, characterized in that: The wastewater from the bottom of the THF recovery tower is heated by steam in the THF recovery tower reboiler and then returned to the THF recovery tower.

3. The method for removing acetal through dehydration reaction in the BDO refining process as described in claim 1, characterized in that: The catalyst is a magnesium-containing mesoporous γ-alumina dehydration catalyst.

4. The method for removing acetal through dehydration reaction in the BDO refining process as described in claim 1, characterized in that: The acetal includes at least one of HBTHF, hydroxybutyral, or acetal.

5. A system for the method of removing acetal via dehydration reaction in the BDO refining process according to claim 1, characterized in that: Includes vaporization and dehydration components, and product distillation components. The vaporization and dehydration assembly includes a vaporizer, a dehydration feed preheater connected to the top of the vaporizer, a dehydration reactor connected to the top of the dehydration feed preheater, and a dehydration heat exchanger connected to the bottom of the dehydration reactor. The dehydration heat exchanger is connected to a raw material inlet. The vaporizer is connected to a steam interface. The bottom of the vaporizer is connected to a dehydration vaporizer circulation pump. The dehydration vaporizer circulation pump is connected to a dehydration heater and a waste liquid tank. The dehydration heater is connected to the vaporizer. The product distillation assembly includes a THF recovery column, a THF recovery column condenser connected to the top of the THF recovery column, a THF recovery column reflux tank connected to the THF recovery column condenser, an incinerator connected to the THF recovery column condenser and the THF recovery column reflux tank, a THF recovery column reflux pump connected to the THF recovery column reflux tank, a THF recovery column bottom pump connected to the bottom of the THF recovery column, an external water treatment device connected to the THF recovery column bottom pump, and the THF recovery column reflux pump connected to both the THF recovery column and the refining unit.

6. The system according to claim 5 for the method of removing acetal by dehydration reaction in the BDO refining process according to claim 1, characterized in that: The THF recovery tower is connected to a THF recovery tower reboiler in its bottom.

7. The system according to claim 5 for use in the dehydration reaction to remove acetal during the BDO refining process according to claim 1, characterized in that: The steam interface is connected to the steam pipeline network.

8. The system according to claim 5 for use in the dehydration reaction to remove acetal during the BDO refining process according to claim 1, characterized in that: The dehydration reactor includes a shell and a series of tubes disposed within the shell. The cavity of the shell is filled with heat-conducting oil, and the series of tubes is filled with a catalyst.

9. The system according to claim 5 for use in the dehydration reaction to remove acetal during the BDO refining process according to claim 1, characterized in that: The THF recovery tower is a plate distillation tower with a theoretical number of 10 to 30 plates.

10. The system according to claim 5 for the method of removing acetal by dehydration reaction in the BDO refining process according to claim 1, characterized in that: The vaporizer is equipped with metal Pall ring packing, with a theoretical number of 5 to 10 plates.

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