A high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid

Abstract

The present invention discloses a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid: the interior of the tower includes three parts from top to bottom: the upper part is a distillation section, the middle part is a catalytic reaction section, and the lower part is a stripping section. The distillation section and the stripping section are filled with tower internals, and the catalytic reaction section is filled with a combined structured packing filled with catalyst. A gas phase outlet is provided at the top of the tower, a reflux port is provided at the upper part of the tower wall, an excess monomer inlet I is provided at the middle and upper part of the tower wall and is connected to the bottom of the distillation section, or an excess monomer inlet II is provided at the middle and lower part of the tower wall and is connected to the top of the stripping section; an inlet for a mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate is provided at the middle part of the tower wall and is connected to the lower part of the catalytic reaction section, and a discharge port is provided at the bottom of the tower; a gas phase outlet is connected to a condenser, and the outlet of the condenser is connected to a phase separation tank. The present invention solves the technical problem of insufficient catalytic and separation capacity of a catalytic distillation tower for esterification of ethylene glycol and acetic acid.

Description

Technical Field

[0001] The invention relates to a catalytic distillation tower for esterification of ethylene glycol and acetic acid, in particular to a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid. Background Art

[0002] The industrial production of ethylene glycol diacetate by esterification of ethylene glycol and acetic acid is a common technical route, and the production process involves multiple applications of catalytic distillation towers.

[0003] Chinese patents CN 104045554 A and CN 109369396 A disclose a method for producing ethylene glycol diacetate using acetic acid and ethylene glycol as raw materials. The catalytic distillation tower in the production process has a problem of producing wastewater containing more than 5% acetic acid at the top of the tower due to insufficient catalytic capacity and separation capacity, resulting in wastewater containing more than 5% acetic acid at the top of the tower, causing waste of raw acetic acid. The high acetic acid content in the wastewater is difficult to handle, resulting in reduced economic benefits and environmental pressure, and the ethylene glycol diacetate product at the bottom of the tower has a high impurity content. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid in view of the deficiencies in the prior art, so as to solve the technical problem of insufficient catalytic and separation capacity of the existing catalytic distillation tower for esterification of ethylene glycol and acetic acid.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid, the tower interior comprises three parts from top to bottom: the upper part is a distillation section, the middle part is a catalytic reaction section, and the lower part is a stripping section, the distillation section and the stripping section are filled with tower internals, and the catalytic reaction section is filled with a catalyst assembly;

[0007] Tower exterior: a gas phase outlet is provided at the tower top; a reflux port is provided at the upper part of the tower wall, and the reflux port is connected to the top of the distillation section; an excess monomer inlet I is provided at the middle and upper part of the tower wall, and the excess monomer inlet I is connected to the bottom of the distillation section, or an excess monomer inlet II is provided at the middle and lower part of the tower wall, and the excess monomer inlet II is connected to the top of the stripping section; an inlet for a mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate is provided at the middle part of the tower wall, and the inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate is connected to the lower part of the catalytic reaction section; a discharge port is provided at the bottom of the tower.

[0008] In the above technical solution, the catalytic distillation tower, the excess monomer inlet I and the excess monomer inlet II are connected to a device capable of providing ethylene glycol or acetic acid according to the different functions of the catalytic distillation tower.

[0009] In the above technical solution, when the monomer introduced into the catalytic distillation tower is ethylene glycol, an excess monomer inlet I is provided at the upper middle part of the tower wall, and the excess monomer inlet I is connected to a device capable of providing ethylene glycol.

[0010] In the above technical solution, when the monomer introduced into the catalytic distillation tower is acetic acid, an excess monomer inlet II is provided at the lower middle part of the tower wall, and the excess monomer inlet II is connected to a device capable of providing acetic acid.

[0011] In the above technical solution, the gas phase outlet is connected to a condenser having a cooling or condensing function, and the outlet of the condenser is connected to a phase separation tank having a phase separation function.

[0012] In the above technical scheme, there is an entrainer in the phase separation tank. After phase separation, the upper layer is the entrainer, which flows out through the corresponding outlet and then returns to the catalytic distillation tower through the reflux port. The material in the lower layer flows out through the corresponding outlet and then is connected to other devices or storage tanks.

[0013] In the above technical solution, the inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate is connected to a device capable of providing the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate.

[0014] In the above technical solution, the discharge port is connected to a downstream device or a product storage tank.

[0015] In the above technical solution, the tower internals filled in the stripping section and the rectifying section are tower plates, and the number of tower plates N is: 1<N<200, preferably 5<N<100; the distance between the tower plates is 400-600mm.

[0016] In the above technical solution, the catalyst assembly loaded in the catalytic reaction section is the combined structured packing for loading catalysts recorded in CN204656548U, and the catalyst loaded in the combined structured packing for loading catalysts is catalyst A.

[0017] In the above technical solution, the catalyst A is a solid acid catalyst, preferably a macroporous sulfonic acid cationic resin catalyst.

[0018] In the above technical scheme, the combined regular packing for loading catalyst in CN204656548U includes catalyst mold pieces and metal filler sheet groups; the catalyst mold pieces are formed by pressing a metal diamond plate mesh lined with a metal wire mesh of the same material into a specified shape, loading catalyst A particles and spot welding and sealing; the metal filler sheets are formed by filling metal wire mesh corrugated fillers or metal perforated plate corrugated fillers between catalyst mold pieces and welding; the catalyst mold pieces and filler sheets are arranged linearly and evenly spaced along the diameter direction of the distillation tower, and are formed into a catalytic distillation element module by using a steel belt bundle of the same material as the diamond plate mesh; the catalyst mold pieces are made of stainless steel diamond plate mesh and 60-mesh stainless steel wire mesh of the same material, which are spot welded and pressed into two isosceles trapezoidal structures with a bottom angle of not less than 60°, and sealed at both ends; the catalyst mold pieces and the metal filler sheet group are assembled and combined by one or more modules.

[0019] In the above technical solution, the feed amount of the excess monomer inlet I or the excess monomer II ensures that in the mixture in the catalytic distillation tower, the molar ratio of the total reactive groups of the excess monomer to the other reactive groups is 1.0 to 2.0:1, preferably 1.2:1.

[0020] In the above technical scheme, when the high-efficiency catalytic distillation tower of the present invention is used for esterification of ethylene glycol and acetic acid, the material ratio of ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate, etc., the space velocity and the reaction conditions can be operated according to conventional procedures.

[0021] The advantages of the technical solution of the present invention are:

[0022] (1) The excess monomer inlet of the present invention can be used to introduce different monomers according to different functional requirements of the catalytic distillation tower. When the monomer is ethylene glycol, an excess monomer inlet I is set at the bottom of the rectifying section, and the material in the lower layer of the phase separation tank at the top of the tower is wastewater. The acetic acid content in the wastewater is less than 100 ppm, which can be directly discharged into a sewage treatment plant without generating other pollution sources. Therefore, the present invention has both obvious environmental advantages and obvious economic advantages of saving material acetic acid. When the monomer is acetic acid, a monomer inlet II is set at the top of the stripping section, and the product quality of the bottom discharge is excellent: the concentration of ethylene glycol diacetate is ≥99.5%, the concentration of ethylene glycol monoacetate is ≤0.2%, water is ≤0.1%, acetic acid is ≤0.2%, and ethylene glycol is ≤0.001%.

[0023] (2) The catalytic section of the catalytic distillation tower of the present invention is filled with structured packing, and the efficiency of catalyst reaction and separation is higher.

[0024] (3) Small footprint and effective use of space;

[0025] (4) The equipment has a simple structure, is easy to manufacture, and requires low investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : A schematic diagram of the overall structure of a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid according to the present invention;

[0027] Figure 2 : A schematic diagram of the overall structure of a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid according to the present invention (when the monomer is ethylene glycol);

[0028] Figure 3 : A schematic diagram of the overall structure of a high-efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid according to the present invention (when the monomer is acetic acid);

[0029] Among them: 1 is the gas phase outlet, 2 is the reflux port; 3 is the distillation section; 41 is the excess monomer inlet I; 42 is the excess monomer inlet II; 5 is the catalytic reaction section; 6 is the inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate; 7 is the stripping section; and 8 is the discharge port. DETAILED DESCRIPTION

[0030] The following is a detailed description of the specific implementation of the technical solution of the present invention, but the present invention is not limited to the following description:

[0031] A high efficiency catalytic distillation tower for esterification of ethylene glycol and acetic acid, such as Figure 1-3 As shown: the interior of the tower includes three parts from top to bottom: the upper part is the rectification section 3, the middle part is the catalytic reaction section 5, and the lower part is the stripping section 7;

[0032] The rectifying section and the stripping section are filled with tower internals, the tower internals are tower plates, the number of tower plates N is: 1<N<200, preferably 5<N<100; the distance between tower plates is 400-600mm;

[0033] The catalytic reaction section is filled with a catalyst assembly; the catalyst assembly is a combined structured packing filled with catalysts recorded in CN204656548U, the catalyst loaded in the combined structured packing filled with catalysts is catalyst A, catalyst A is a solid acid catalyst, preferably a macroporous sulfonic acid cationic resin catalyst;

[0034] A gas phase outlet 1 is provided at the top of the tower, a reflux port 2 is provided at the upper part of the tower wall, and the reflux port is connected to the top of the distillation section; the gas phase outlet is connected to a condenser with a cooling or condensing function, and the outlet of the condenser is connected to a phase separation tank with a phase separation function; there is an entrainer in the phase separation tank, and after phase separation, the upper layer is the entrainer, which flows out through the corresponding outlet and then returns to the catalytic distillation tower through the reflux port, and the material in the lower layer flows out through the corresponding outlet and then is connected to other devices or storage tanks;

[0035] An excess monomer inlet I 41 is provided at the upper middle portion of the tower wall, and the excess monomer inlet I is connected to the bottom of the rectifying section, and in this case, the excess monomer inlet I is connected to a device capable of providing ethylene glycol; or an excess monomer inlet II 42 is provided at the lower middle portion of the tower wall, and the excess monomer inlet II is connected to the top of the stripping section, and the excess monomer inlet II is connected to a device capable of providing acetic acid, such as Figure 2 and 3 As shown;

[0036] An inlet (6) for a mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate is provided in the middle of the tower wall, and the inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate is connected to the lower part of the catalytic reaction section; the inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate is connected to a device capable of providing a mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate;

[0037] A discharge port 8 is provided at the bottom of the tower, and the discharge port is connected to a downstream device or a product storage tank.

[0038] In the present invention, the combined regular filler for loading catalyst in CN204656548U comprises a catalyst die and a metal filler sheet group; the catalyst die is formed by pressing a metal diamond plate mesh lined with a metal wire mesh of the same material into a specified shape, loading catalyst A particles and spot welding and sealing; the metal filler sheet is formed by filling a metal wire mesh corrugated filler or a metal perforated plate corrugated filler sheet between the catalyst die and welding; the catalyst die and the filler sheet are arranged linearly and equidistantly along the diameter direction of the distillation tower at intervals, and a catalytic distillation element module is formed by using a steel belt bundle of the same material as the diamond plate mesh; the catalyst die is made of a stainless steel diamond plate mesh and a 60-mesh stainless steel wire mesh of the same material, which are spot welded and pressed into two isosceles trapezoidal structures with a cross-section bottom angle of not less than 60°, and sealed at both ends; the catalyst die and the metal filler sheet group are assembled and combined by one or more modules.

[0039] In the present invention, the feed amount of the excess monomer inlet I or the excess monomer II ensures that the molar ratio of the total reactive groups of the excess monomer to the other reactive groups in the mixture in the catalytic distillation tower is 1.0-2.0:1, preferably 1.2:1.

[0040] In the present invention, when the high-efficiency catalytic distillation tower of the present invention is used for esterification of ethylene glycol and acetic acid, the material ratio of ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate, etc., the space velocity, the reaction conditions, etc. can all be operated according to conventional procedures.

[0041] The present invention will be described below in conjunction with specific embodiments:

[0042] Embodiment 1:

[0043] A high-efficiency catalytic distillation tower is used for the esterification of ethylene glycol and acetic acid. The equipment structure of this embodiment is shown in Figure 2 , specifically including the following steps:

[0044] The test was conducted on a pilot 500L catalytic distillation tower device. The flow rates of the various substances in the feed of the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate inlet 6 were: ethylene glycol 10 mol / h, acetic acid 70 mol / h, ethylene glycol monoacetate 10 mol / h, and ethylene glycol diacetate 80 mol / h; the flow rate of ethylene glycol in the feed of the excess monomer inlet 4 was 74 mol / h;

[0045] In the high-efficiency catalytic distillation tower: the theoretical number of plates in the distillation section is 25 (with a spacing of 500 mm), and the reflux ratio is 1; the height of the combined regular packing in the catalytic reaction section is 1 meter, and the theoretical number of plates in the stripping section is 25 (with a spacing of 500 mm).

[0046] The operating conditions of the catalytic distillation tower top are: temperature 85-90℃, pressure 0.10-0.15Mpa, and the operating conditions of the tower bottom are: temperature 165-170℃, pressure 0.25-0.30Mpa. The operating conditions of the catalytic distillation reaction section are: space velocity 2h -1 , the reaction temperature is 100-110°C, and the reaction pressure is 0.15-0.20Mpa;

[0047] In this embodiment, the lower layer of the tower top phase separation tank (i.e., reflux tank) is wastewater, and the acetic acid content in the wastewater is less than 100 ppm, which can be directly discharged from the device and sent to a sewage treatment plant; under the efficient catalytic and separation effect of the reaction section combined regular filler, the acetic acid conversion rate reaches 99.85%.

[0048] Embodiment 2:

[0049] A high-efficiency catalytic distillation tower is used for the esterification of ethylene glycol and acetic acid. The equipment structure of this embodiment is shown in Figure 3 , specifically including the following steps:

[0050] The test was conducted on a pilot 500L catalytic distillation tower device. The flow rates of the various substances in the feed of the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate inlet 6 were: ethylene glycol 19.36 mol / h, acetic acid 0.36 mol / h, ethylene glycol monoacetate 69.64 mol / h, ethylene glycol diacetate 85 mol / h; the flow rate of acetic acid in the feed of the excess monomer inlet 4 was 177.6 mol / h;

[0051] In the high-efficiency catalytic distillation tower: the theoretical number of plates in the distillation section is 25 (with a spacing of 500 mm), and the reflux ratio is 1; the height of the combined regular packing in the catalytic reaction section is 1 meter, and the theoretical number of plates in the stripping section is 25 (with a spacing of 500 mm).

[0052] The operating conditions of the top of the catalytic distillation tower are: temperature 110-115°C, pressure 0.10-0.15Mpaa, the operating conditions of the bottom of the tower are: temperature 180-185°C, pressure 0.25-0.30Mpa; the reaction conditions of the reaction section of the catalytic distillation tower are: space velocity 2h -1 , the reaction temperature is 115-120°C, and the reaction pressure is 0.15-0.20Mpa.

[0053] In this embodiment, the concentration of ethylene glycol diacetate in the bottom discharge is 99.5%, the concentration of ethylene glycol monoacetate is 0.2%, water ≤ 0.1%, acetic acid ≤ 0.2%, and ethylene glycol ≤ 0.001%. Under the efficient catalytic and separation effect of the reaction section combined regular packing, it can be seen that the ethylene glycol conversion rate reaches 99.81%.

[0054] The above examples are only for illustrating the technical concept and technical features of the present invention, and cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower, characterized in that: The interior of the catalytic distillation tower used comprises three parts from top to bottom: the upper part is a distillation section (3), the middle part is a catalytic reaction section (5), and the lower part is a stripping section (7). The distillation section and the stripping section are filled with tower internals, and the catalytic reaction section is filled with a catalyst assembly. The tower is provided with a gas phase outlet (1) at the top of the tower; a reflux port (2) is provided at the upper part of the tower wall, and the reflux port is connected to the top of the distillation section; an excess monomer inlet I (41) is provided at the upper middle part of the tower wall, and the excess monomer inlet I is connected to the bottom of the distillation section; an ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate mixture inlet (6) is provided at the middle part of the tower wall, and the ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate mixture inlet is connected to the lower part of the catalytic reaction section; a discharge port (8) is provided at the bottom of the tower; the excess monomer inlet I (41) is connected to a device capable of providing ethylene glycol; The method for esterifying ethylene glycol and acetic acid using a catalytic distillation tower specifically comprises the following steps: the flow rates of the various substances in the feed of the mixture inlet of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate are: 10 mol / h of ethylene glycol, 70 mol / h of acetic acid, 10 mol / h of ethylene glycol monoacetate, and 80 mol / h of ethylene glycol diacetate; the flow rate of ethylene glycol in the feed of the excess monomer inlet I is 74 mol / h; : The number of theoretical plates in the rectification section is 25, the spacing is 500mm, the reflux ratio is 1, the height of the catalytic reaction section combination packing is 1 meter, the number of theoretical plates in the stripping section packing is 25, and the spacing is 500mm; the operating conditions of the top of the catalytic distillation tower are: temperature is 85-90℃, pressure is 0.10-0.15Mpa; the operating conditions of the bottom of the tower are: temperature is 165-170℃, pressure is 0.25-0.30Mpa; the operating conditions of the catalytic distillation reaction section are: space velocity is 2h -1 , the reaction temperature is 100-110°C, and the reaction pressure is 0.15-0.20Mpa.

2. A method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower, characterized in that: The interior of the catalytic distillation tower used comprises three parts from top to bottom: the upper part is a distillation section (3), the middle part is a catalytic reaction section (5), and the lower part is a stripping section (7). The distillation section and the stripping section are filled with tower internals, and the catalytic reaction section is filled with a catalyst assembly. The tower is provided with a gas phase outlet (1) at the top of the tower; a reflux port (2) is provided at the upper part of the tower wall, and the reflux port is connected to the top of the distillation section; an excess monomer inlet II (42) is provided at the middle and lower part of the tower wall, and the excess monomer inlet II is connected to the top of the stripping section; an ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate mixture inlet (6) is provided at the middle part of the tower wall, and the ethylene glycol, acetic acid, ethylene glycol monoacetate, ethylene glycol diacetate mixture inlet is connected to the lower part of the catalytic reaction section; a discharge port (8) is provided at the bottom of the tower; the excess monomer inlet II (42) is connected to a device capable of providing acetic acid; The method for esterifying ethylene glycol and acetic acid using a catalytic distillation tower specifically comprises the following steps: the flow rates of the various substances in the feed of the mixture inlet (6) of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate are: 19.36 mol / h of ethylene glycol, 0.36 mol / h of acetic acid, 69.64 mol / h of ethylene glycol monoacetate, and 85 mol / h of ethylene glycol diacetate; the flow rate of acetic acid in the feed of the excess monomer inlet (4) is 177.6 mol / h; the high efficiency catalytic distillation tower is used for the esterification of ethylene glycol and acetic acid, and the flow rate of the various substances in the feed of the mixture inlet (6) of ethylene glycol, acetic acid, ethylene glycol monoacetate, and ethylene glycol diacetate is 19.36 mol / h, 0.36 mol / h of acetic acid, 69.64 mol / h of ethylene glycol diacetate, and the flow rate of the acetic acid in the feed of the excess monomer inlet (4) is 177.6 mol / h; the high efficiency catalytic distillation tower is used for the esterification of ethylene glycol and acetic acid ... In the distillation tower: the number of theoretical plates in the distillation section is 25, the spacing is 500mm, and the reflux ratio is 1; the height of the catalytic reaction section combined regular packing is 1 meter, and the number of theoretical plates of the stripping section packing is 25, and the spacing is 500mm; the operating conditions of the top of the catalytic distillation tower are: temperature is 110-115℃, pressure is 0.10-0.15Mpaa, and the operating conditions of the bottom of the tower are: temperature is 180-185℃, pressure is 0.25-0.30Mpa; the reaction conditions of the reaction section of the catalytic distillation tower are: space velocity is 2h -1 , the reaction temperature is 115-120°C, and the reaction pressure is 0.15-0.20Mpa.

3. The method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower according to claim 1 or 2, characterized in that: The gas phase outlet is connected to a condenser with a cooling or condensing function, and the outlet of the condenser is connected to a phase separation tank with a phase separation function.

4. The method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower according to claim 3, characterized in that: There is an entrainer in the phase separation tank. After phase separation, the upper layer is the entrainer, which flows out through the corresponding outlet and returns to the catalytic distillation tower through the reflux port. The material in the lower layer flows out through the corresponding outlet and is connected to other devices or storage tanks.

5. The method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower according to claim 1 or 2, characterized in that: The inlet for the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate is connected to a device capable of providing the mixture of ethylene glycol, acetic acid, ethylene glycol monoacetate and ethylene glycol diacetate.

6. The method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower according to claim 1 or 2, characterized in that: The discharge port is connected to a downstream device or a product storage tank.

7. The method for esterification of ethylene glycol and acetic acid using a catalytic distillation tower according to claim 1 or 2, characterized in that: The catalyst assembly filled in the catalytic reaction section is a combined regular filler filled with catalyst: it includes a catalyst die and a metal filler sheet group; the catalyst die is formed by pressing a metal diamond plate mesh lined with a metal wire mesh of the same material into a specified shape, loading catalyst A particles and spot welding and sealing; the metal filler sheet is formed by filling a metal wire mesh corrugated filler or a metal perforated plate corrugated filler sheet between the catalyst die and welding; the catalyst die and the filler sheet are arranged linearly and evenly spaced along the diameter direction of the distillation tower at intervals, and a catalytic distillation element module is formed by using a steel belt bundle of the same material as the diamond plate mesh; the catalyst die is made of a stainless steel diamond plate mesh and a 60-mesh stainless steel wire mesh of the same material, which are spot welded and pressed into two isosceles trapezoidal structures with a cross-section bottom angle of not less than 60°, and the two ends are sealed; the catalyst die and the metal filler sheet group are assembled and combined by one or more modules; the catalyst A is a solid acid catalyst.

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