Catalyst package based on distillation tower filler and its filling structure

Abstract

The present invention discloses a catalyst package based on distillation tower packing and a filling structure thereof, which comprises a wire mesh tube, on which a plurality of straight-line seals are arranged along the length direction, the angle between any two adjacent seals is 90°, and the seals divide the wire mesh tube into a plurality of catalyst mesh package units. The present invention has the following beneficial effects: the radial cross-sectional shapes of the catalyst mesh package units of the present invention are constantly changing, the liquid phase is more likely to have turbulence on the surface of the catalyst package, and is more likely to invade the wire mesh and contact the catalyst, thereby improving the gas-liquid mass transfer and the reaction rate; the straight-line seals at both ends of the catalyst mesh package unit are staggered at an angle of 90°, so that the catalyst mesh package itself has excellent deformation adaptability and deformation automatic recovery performance, so that the catalyst mesh package unit has both the tendency of being radially supported by the expansion force of the catalyst to be rounded and the ability to automatically rebound to be out of round, thereby protecting the small particle catalyst and the catalyst mesh package unit.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst filling of a distillation tower, in particular to a catalyst package based on distillation tower filler and a filling structure thereof. Background Art

[0002] A catalytic distillation tower is a chemical equipment that couples reaction and separation. The catalytic filler in the reaction section must play a role in both reaction and vapor-liquid mass transfer. Good catalyst loading technology is the key to improving the efficiency of catalytic distillation. Currently, most solid catalysts in industrial production use ion exchange resins, molecular sieves or solid superacids. In order to ensure that the catalyst does not hinder the flow of vapor and liquid in the catalytic filler section of the catalytic distillation tower reaction, and also plays a catalytic role, a variety of patents have proposed the use of small-particle solid catalyst technology.

[0003] For example, the patent publication number CN1569301A, "A catalytic distillation component and a catalytic distillation method using the component", proposes a technical solution of placing small particle catalysts into a cylindrical, elliptical, polygonal and other wire mesh containers to form a catalyst package. However, regardless of whether the catalyst package is cylindrical, elliptical or polygonal, the radial cross-section of the middle section is the same shape, and the catalyst is accumulated in the catalyst package. During the gas-liquid mass transfer process, the cylindrical catalyst package has a large resistance to movement in the long axis direction, and most of the flowing gas and liquid pass along the outer surface of the catalyst wire mesh. The catalyst in the wire mesh can only contact a small part of the gas and liquid. The catalyst is poorly suspended and dispersed in the catalyst package during the gas-liquid mass transfer process, resulting in poor efficiency of catalyst-enhanced effective reaction and low catalyst utilization. At the same time, the catalyst package formed by the catalyst in a cylindrical, elliptical, polygonal and other wire mesh container is difficult to handle or protect during the production, transportation, installation, and device startup and shutdown stages. Improper methods can easily cause the small-particle solid catalyst in the catalyst package to lose liquid or partially lose liquid and shrink. When the catalyst package is placed vertically, the small-particle solid catalyst in the catalyst package will fall and gather to fill the middle and lower part of the catalyst package. When the liquid is obtained again, the small-particle solid catalyst expands and is finally held by the wire mesh to form a compacted, tight cylindrical small-particle solid catalyst accumulation. Since the cylindrical catalyst package has no buffer margin in the radial direction when the small-particle catalyst expands from dry to wet, the particle catalyst in the middle and lower part of the catalyst package is bounded by the wire mesh in the radial direction and forms an embolism as soon as it expands, hindering the expansion path of the small-particle catalyst along the axial direction to the catalyst-free gap upward. Continuing to expand will burst the wire mesh or be overly bound by the wire mesh, causing the small-particle catalyst to squeeze each other and break into powder, and even cause the wire mesh to be damaged. The escaping catalyst will gather and cause a series of problems such as increased pressure drop in the distillation tower and filter clogging. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The purpose of the present invention is to provide a catalyst package based on distillation tower filler and its filling structure to solve the technical problems in the prior art that small particle catalyst packages have low mass transfer efficiency, slow reaction rate, and easy breakage of catalysts, which leads to increased pressure drop in the distillation tower and filter clogging.

[0006] (II) Technical solution

[0007] Content of the present invention: A catalyst package based on distillation tower packing comprises a wire mesh tube, on which a plurality of straight-line seals are arranged along the length direction, the angle between any two adjacent seals is 90°, the seals divide the wire mesh tube into a plurality of catalyst mesh package units, small-particle catalysts are installed in the catalyst mesh package units, the shapes of any cross sections of the catalyst mesh package units are different, the cross-sectional area of ​​the catalyst mesh package units gradually decreases from the center to both ends, the particle size of the small-particle catalyst is larger than the mesh aperture of the wire mesh tube, and the small-particle catalyst occupies 60%-80% of the space of the catalyst mesh package unit.

[0008] Furthermore, the ratio of the axial length to the circumference of the catalyst mesh bag unit is less than 3.

[0009] Furthermore, the wire mesh cylinder is made of stainless steel or glass fiber or polyamide fiber.

[0010] Furthermore, the mesh number of the wire mesh tube is 20-150 meshes.

[0011] Furthermore, the particle size of the small particle catalyst is 0.5 mm to 2.0 mm.

[0012] Preferably, the filling structure based on the catalyst package of the distillation tower packing includes a catalyst mesh bag unit and a cylindrical packing bed layer, and a plurality of the catalyst mesh bag units are inserted in the packing bed layer.

[0013] Furthermore, the packing bed layer includes a plurality of vertically arranged porous corrugated plates, the upper and lower ends of all the porous corrugated plates are aligned, the corrugations of any two adjacent porous corrugated plates are in opposite directions, and the catalyst mesh bag unit is inserted in the trough of the porous corrugated plates.

[0014] Furthermore, a porous mesh plate is connected to the bottom end of the packing bed.

[0015] Furthermore, the angle between the corrugation direction of the porous corrugated plate and the axis of the distillation tower is 30°-45°.

[0016] Furthermore, the porous corrugated plate is made by calendering a stainless steel wire mesh.

[0017] (III) Beneficial effects

[0018] Beneficial effects of the present invention: the radial cross-sectional shapes of the catalyst mesh bag unit of the present invention are constantly changing, the liquid phase is more likely to have turbulence on the surface of the catalyst bag, and is more likely to invade the wire mesh to contact the small particle catalyst. At the same time, under the stirring effect of the rising vapor phase, the small particle catalyst is more likely to remain in a suspended and dispersed state in the liquid phase, thereby improving the vapor-liquid mass transfer and reaction rate, and increasing the product output; the radial cross-sectional shapes of the catalyst mesh bag unit are constantly changing and are not round. During the production, transportation, installation, start-up and shutdown of the catalyst mesh bag, the small particle catalyst may lose liquid or partially lose liquid and shrink, and then expand after gaining liquid, and the catalyst The radial expansion of the catalyst in the mesh bag unit drives the radial cross-section of the catalyst bag to change from non-circular to circular, thereby buffering the expansion force, reducing the crushing and pulverization rate of small-particle catalysts, and preventing small-particle catalysts from escaping from the catalyst bag and causing adverse effects on the production system; the straight-line seals at both ends of the catalyst mesh bag unit are staggered at an angle of 90°, so that the catalyst mesh bag unit itself has excellent deformation adaptability and automatic deformation recovery performance, and the catalyst mesh bag unit has both the tendency to be radially supported by the expansion force of the catalyst to be round and the ability to automatically rebound to a non-circular state, thereby protecting the small-particle catalyst and the catalyst mesh bag unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of vapor-liquid mass transfer of the catalyst mesh bag unit of the present invention;

[0020] Figure 2 for Figure 1 Section views along AA, BB, CC, DD, and EE;

[0021] Figure 3 A three-dimensional diagram of the catalyst mesh bag unit of the present invention;

[0022] Figure 4 This is a diagram showing the installation position of the catalyst mesh package unit in the porous mesh plate of the present invention;

[0023] Figure 5 is a three-dimensional diagram of the packing bed of the present invention;

[0024] Figure 6 This is a schematic diagram of the application of the packing bed of the present invention;

[0025] In the figure, there are seal 2, small particle catalyst 3, porous corrugated plate 4, catalyst mesh package unit 6, and porous mesh plate 7. DETAILED DESCRIPTION

[0026] Example 1

[0027] like Figures 1 to 3As shown, the present invention is applied to the reactive distillation production process for preparing glycolic acid by hydrolyzing methyl glycolate, 5 straight seals 2 are arranged on the wire mesh cylinder along the length direction, the seals 2 can be realized by resistance welding, the angle between any two adjacent seals 2 is 90°, the seals 2 divide the wire mesh cylinder into 4 catalyst mesh bag units 6, small particle catalyst 3 is installed in the catalyst mesh bag unit 6, the shape of any cross section of the catalyst mesh bag unit 6 is different, the cross-sectional area of ​​the catalyst mesh bag unit 6 gradually decreases from the center to both ends, the small particle catalyst 3 occupies 70% of the space of the catalyst mesh bag unit 6, the charging volume of a single catalyst mesh bag unit 6 is about 45mm³, the total charging volume is 2.5m³, and the specific catalyst mesh bag unit 6 has an axial length and a circumference ratio of 1.0, the wire mesh cylinder is made of stainless steel, the mesh number of the wire mesh cylinder is 30 meshes, the diameter of the wire mesh cylinder is 10mm, the small particle catalyst 3 uses a commonly used cation exchange resin catalyst, and the particle size of the small particle catalyst 3 is 1.0mm.

[0028] like Figures 4 to 6 As shown, the filling structure of the catalyst package based on the distillation tower packing includes a catalyst mesh bag unit 6 and a cylindrical packing bed layer, in which a plurality of the catalyst mesh bag units 6 are inserted; the packing bed layer includes a plurality of vertically arranged porous corrugated plates 4, the upper and lower ends of all the porous corrugated plates 4 are aligned, and the corrugations of any two adjacent porous corrugated plates 4 are in opposite directions, and the catalyst mesh bag unit 6 is inserted in the trough of the porous corrugated plate 4. In order to prevent the catalyst mesh bag unit 6 from falling off, The bottom end of the packing bed is connected to a porous mesh plate 7, the angle between the corrugation direction of the porous corrugated plate 4 and the axis of the distillation tower is 40°, the porous corrugated plate 4 is made of stainless steel wire mesh rolled into a corrugated shape or directly rolled into a corrugated shape by a stainless steel porous plate. Specifically, the circular packing bed can be spliced ​​by multiple packing bed units, and each packing bed unit can be wrapped and fixed with stainless steel wire mesh on all sides. The packing bed loaded in the distillation tower is 27 layers, and the selected distillation tower is a T403 distillation tower with an inner diameter of 1400 mm.

[0029] like Figures 1 to 3As shown in the figure, the radial cross-sectional shapes of the catalyst mesh bag unit 6 of the present invention are constantly changing. The liquid phase L1 is more likely to have turbulence on the surface of the catalyst mesh bag unit 6, and is more likely to invade the wire mesh to contact the small particle catalyst. At the same time, under the stirring effect of the rising vapor phase L2, the small particle catalyst 3 is more likely to remain in a suspended and dispersed state in the liquid phase, thereby improving the vapor-liquid mass transfer and reaction rate; the radial cross-sectional shapes of the catalyst mesh bag unit 6 are constantly changing and are not round. During the production, transportation, installation, start-up and shutdown of the catalyst mesh bag unit 6, the small particle catalyst 3 may lose liquid or partially lose liquid and shrink, and expand again after gaining liquid. The small particle catalyst in the catalyst mesh bag unit 6 The radial expansion of the catalyst 3 drives the radial cross-section of the catalyst mesh bag unit 6 to change from a non-circular shape to a circular shape, thereby buffering the expansion force, reducing the crushing and pulverization rate of the small-particle catalyst 3, and avoiding damage to the small-particle catalyst 3 and the escape of the small-particle catalyst 3, which may have an adverse effect on the production system; the two ends of the catalyst mesh bag unit 6 have a straight-line seal structure with an angle of 90°, so that the catalyst mesh bag unit 6 itself has excellent deformation adaptability and automatic deformation recovery performance, so that the catalyst mesh bag unit 6 has both the tendency of being radially supported by the expansion force of the small-particle catalyst 3 to become round and the ability to automatically rebound to a non-circular shape, thereby protecting the small-particle catalyst 3 and the catalyst mesh bag unit 6.

[0030] Comparative Example 1

[0031] A cylindrical conventional catalyst mesh bag is used, and the small particle catalyst 3 occupies 70% of the space of the conventional catalyst mesh bag. The loading volume of a single conventional catalyst mesh bag is also about 180 mm³ (ie, 45 mm³×4), and the total loading volume is also 2.5 m³. Other process conditions are the same as those in Example 1.

[0032] The following table records the comparison of the weight of the ethanolic acid product produced by Example 1 and Comparative Example 1 after running for 7 days. It can be seen that when other process conditions are the same, the catalyst mesh bag unit 6 with the structure of the present invention can increase the output by about 20%.

[0033] Output (tons) d1 d2 d3 d4 d5 d6 d7 Average daily output Total production Example 1 24.5 24.3 23.9 23.7 24.2 24.5 24.3 24.20 169.4 Comparative Example 1 19.8 20.0 20.8 19.6 20.1 20.3 20.2 20.11 140.8

[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A catalyst package based on a distillation tower packing, characterized in that: The invention comprises a wire mesh cylinder, on which a plurality of straight-line seals (2) are arranged along the length direction, the angle between any two adjacent seals (2) is 90°, the seals (2) divide the wire mesh cylinder into a plurality of catalyst mesh bag units (6), small-particle catalysts (3) are contained in the catalyst mesh bag units (6), the shapes of any cross sections of the catalyst mesh bag units (6) are different, the cross-sectional area of ​​the catalyst mesh bag units (6) gradually decreases from the center to both ends, the particle size of the small-particle catalysts (3) is larger than the mesh hole size of the wire mesh cylinder, and the small-particle catalysts (3) occupy 60%-80% of the space of the catalyst mesh bag units (6).

2. The catalyst package based on distillation tower packing according to claim 1, characterized in that: The wire mesh cylinder is made of stainless steel or glass fiber or polyamide fiber.

3. The catalyst package based on distillation tower packing according to claim 1, characterized in that: The mesh number of the wire mesh cylinder is 20-150 meshes.

4. The catalyst package based on distillation tower packing according to claim 1, characterized in that: The particle size of the small particle catalyst (3) is 0.5 mm to 2.0 mm.

5. The filling structure based on the catalyst package of the distillation tower packing is characterized by: It comprises the catalyst mesh bag unit (6) as claimed in any one of claims 1 to 4, and a cylindrical packing bed, in which a plurality of the catalyst mesh bag units (6) are inserted.

6. The filling structure based on the distillation tower filler catalyst package according to claim 5, characterized in that: The packing bed layer comprises a plurality of vertically arranged porous corrugated plates (4), the upper and lower ends of all the porous corrugated plates (4) are aligned, the corrugations of any two adjacent porous corrugated plates (4) run in opposite directions, and the catalyst mesh bag unit (6) is inserted into the trough of the porous corrugated plates (4).

7. The filling structure based on the distillation tower filler catalyst package according to claim 6, characterized in that: A porous mesh plate (7) is connected to the bottom end of the packing bed.

8. The filling structure based on the distillation tower filler catalyst package according to claim 7, characterized in that: The angle between the corrugation direction of the porous corrugated plate (4) and the axis of the distillation tower is 30°-45°.

9. The filling structure based on the catalyst package of the distillation tower filler according to claim 8, characterized in that: The porous corrugated plate (4) is made by calendering a stainless steel wire mesh.

Images