Novel catalytic distillation module

Abstract

The utility model relates to the technical field of catalytic distillation, and provides a novel catalytic distillation module, which comprises a structured packing assembly and a catalyst, the structured packing assembly is formed by alternately stacking a plurality of structured packing, two adjacent structured packing form a hollow channel, and the catalyst is in bulk in the hollow channel of the whole structured packing assembly. The structured packing comprises a first pore plate, a second pore plate and a metal wire mesh which are sequentially connected, and the first pore plate, the metal wire mesh and the second pore plate are tightly attached and pressed into a corrugated plate shape. The pressure drop of the distillation tower is not increased while the high filling amount is ensured, and the reaction air speed can be adjusted in a large range.

Description

Technical Field

[0001] This utility model relates to the field of catalytic distillation technology, and in particular to a novel catalytic distillation module. Background Technology

[0002] Catalytic distillation is a technique that combines reaction and separation processes within the same apparatus. Based on the difference in boiling points between reactants and products, it separates them simultaneously during the reaction. This process rapidly transfers products generated at the active reaction sites away from the reaction zone. Furthermore, the heat of catalytic reaction serves as the heat of vaporization in the distillation process, simplifying the reaction and improving efficiency. The core component of a catalytic distillation apparatus is the packing material; its form and arrangement have a decisive impact on catalytic distillation. Initially, apparatus used packed packing materials, some of which encapsulated solid particulate catalyst in stainless steel wire mesh, forming spiral bundles for packing within the apparatus. Later, catalysts were mixed into structured packing. These can be categorized into bundled catalyst packing and modular catalyst packing.

[0003] For example, CN2631602Y discloses a catalytic distillation column component, including a catalyst and a structured packing that supports the catalyst and facilitates efficient mass transfer. The catalyst particles are loaded into a mesh bag, which is placed within the troughs of the structured packing. Because the catalyst is loaded into the mesh bag in the same way as in a bundled package, the mass transfer resistance is relatively high.

[0004] For example, CN1042664A discloses a catalytic distillation device, which is set up with several beds and a fractionation tray between two beds. The catalyst in the reaction bed is packed in bulk. This type of method is not much different from the bulk form.

[0005] For example, CN 207628382U discloses a high-permeability catalytic distillation module, which uses high-permeability glass fiber fabric instead of dense stainless steel wire mesh as the coating material for fine particulate resin catalyst, and is supplemented with stainless steel calendered perforated mesh box to process into "resin blocks"; and then arranged and combined with "filler blocks" processed from stainless steel calendered perforated mesh corrugated filler with a corrugated shape of zigzag, in an alternating manner in the horizontal direction. The catalyst as a whole is still wrapped in the catalyst pack, which makes the loading and unloading of the catalyst more troublesome, and the mass transfer resistance drop is relatively large.

[0006] For example, CN107812392A discloses a packing structure and filling method for a methyl tert-butyl ether catalytic distillation tower. The random catalyst packing is filled in the gaps between adjacent structured packings, which can effectively reduce the dead zone and short circuit of the catalyst bed, improve the catalyst efficiency, increase the looseness of the catalyst bed, and avoid compaction and crushing.

[0007] For example, in CN107812392A, the structured packing is an open structure, and the scattered catalyst ions can flow between the structured packing. This will increase the wear of the catalyst. Moreover, in the reactor, the smaller the pressure drop, the higher the gas velocity, and the easier it is to blow the scattered catalyst ions to the area with a large pressure drop, which will aggravate the problem of uneven distribution of the catalyst in the reactor and easily lead to adverse conditions such as channeling and short circuit.

[0008] However, in existing technologies, traditional catalysts need to be wrapped in asbestos cloth, or a dense wire mesh needs to be added to the outside of the structured packing box. These methods increase the mass transfer resistance between the material and the catalyst, reduce the probability of the catalyst and material contacting each other in the middle position, and reduce the full utilization of catalytic performance. In these methods, when the outer catalyst is deactivated, the inner catalyst has not completely lost its activity, which leads to an increase in operating costs. At the same time, because the catalytic distillation components in these patented technologies are all in a wrapped state, it is not conducive to the conduction of reaction heat, which can easily lead to the temperature inside the wrapping body rising and triggering side reactions. Utility Model Content

[0009] The purpose of this invention is to solve the problem that in the existing technology, the catalyst needs to be wrapped in asbestos cloth or a dense wire mesh needs to be added outside the structured packing box. These methods will increase the mass transfer resistance between the material and the catalyst, reduce the probability of the catalyst contacting the material in the middle position, and reduce the full utilization of catalytic performance.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: a novel catalytic distillation module, comprising a structured packing assembly and a catalyst, wherein the structured packing assembly is composed of multiple structured packings stacked alternately, with adjacent two structured packings forming a hollow channel, and the catalyst being loosely packed in the hollow channel of the structured packing assembly, wherein the structured packing includes a first perforated plate, a second perforated plate, and a metal wire mesh, which are connected in sequence as the first perforated plate, the metal wire mesh, and the second perforated plate, and are tightly bonded and pressed into a corrugated plate shape.

[0011] In a preferred embodiment, the corrugated cross section of the structured packing is a sine wave with an amplitude of 100-300 mm, a period of 400-600 mm, and a thickness of 1.5-6 mm.

[0012] In a preferred embodiment, the holes in the first and second perforated plates are either nail-shaped holes or bridge-shaped holes.

[0013] In a preferred embodiment, the opening size of the nail hole or bridge hole is: width: 0.8-10mm, height: 0.2-1mm, and the opening ratio of the hole plate is greater than 40%.

[0014] In a preferred embodiment, the opening directions of the nail holes or bridge holes on the first and second perforated plates are consistent.

[0015] In one preferred embodiment, the mesh size of the metal wire mesh is 10-200 mesh.

[0016] In a preferred embodiment, the bonding method between the first perforated plate, the second perforated plate and the wire mesh is one of hot pressing, welding, bonding and screw connection.

[0017] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0018] This invention improves processing capacity by increasing the catalyst loading of the catalytic distillation module. The catalytic distillation module can ensure a sufficiently large void ratio to meet the throughput requirements of the gas-liquid two-phase system. It ensures high loading without increasing the pressure drop of the distillation column and allows for a wide range of adjustment of the reaction space velocity. Attached Figure Description

[0019] Figure 1 A schematic diagram of a structured packing for a novel catalytic distillation module provided by this utility model;

[0020] Figure 2 A schematic diagram of a structured packing assembly and a catalyst-filling structure for a novel catalytic distillation module provided by this utility model;

[0021] Figure 3 This utility model provides a schematic diagram of a novel catalytic distillation module in which the air inlet changes its flow direction through a structured packing orifice plate. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1-3 This utility model provides a technical solution: a novel catalytic distillation module, including a structured packing assembly and a catalyst. The structured packing assembly is composed of multiple structured packings stacked alternately, with adjacent structured packings forming a hollow channel. The catalyst is dispersed in the hollow channel of the structured packing assembly. The structured packing includes a first perforated plate, a second perforated plate, and a metal wire mesh, which are connected in sequence. The three are tightly bonded and pressed into a corrugated plate shape.

[0024] like Figure 1-3 As shown, the corrugations on the cross-section of the structured packing are sinusoidal waves with an amplitude of 100-300 mm, a period of 400-600 mm, and a thickness of 1.5-6 mm.

[0025] like Figure 1-3 As shown, the holes in the first and second perforated plates are either nail-shaped holes or bridge-shaped holes.

[0026] like Figure 1-3 As shown, the opening dimensions of the nail-shaped hole or bridge-shaped hole are: width: 0.8-10mm, height: 0.2-1mm, and the opening ratio of the hole plate is greater than 40%.

[0027] like Figure 1-3 As shown, the opening directions of the nail holes or bridge holes on the first and second perforated plates are consistent.

[0028] like Figure 1-3 As shown, the mesh size of the metal wire mesh is 10-200 mesh.

[0029] like Figure 1-3 As shown, the bonding method between the first perforated plate, the second perforated plate and the wire mesh is one of the following: hot pressing, welding, bonding, or screw connection.

[0030] Working principle: In use, the catalytic distillation module is used for the production of methyl tert-butyl ether, using methanol and C4 mixture as raw materials.

[0031] Fabrication of the structured packing assembly: The first and second perforated plates are made of the same material, thickness, and have the same opening size. The perforated plates are 1mm thick and made of stainless steel. The openings are nail-shaped, 10mm wide, and 0.6mm high. The wire mesh has a 100-mesh opening and a thickness of 0.8mm. A layer of wire mesh is sandwiched between the two perforated plates. The three are welded together by spot welding and then bent and pressed into a sine wave-shaped corrugated plate. The amplitude of the sine wave is 300mm and the period is 500mm, which is the structured packing. The structured packing is stacked in multiple layers to form a structured packing assembly. The corrugated edges of two adjacent structured packings are perpendicular, and a hollow channel is formed between two adjacent structured packings. The catalyst is spherical particles with a diameter between 0.8 and 3mm.

[0032] The catalytic distillation column has an inner diameter of 1.5m. Structured packing is pre-fixed into small sections according to angles (the corrugated edges of adjacent sections are perpendicular to each other). These sections are introduced through a manhole, and the packing must be smaller than the manhole itself. They are placed on a support plate (the support plate has a horizontally placed 80-mesh wire mesh for supporting catalyst particles). Multiple sections of structured packing are successively added and assembled into a complete set of structured packing components inside the column. Each set of components is 20cm high and cylindrical. The gaps between the sides and the column wall are filled with asbestos cloth, tightened to prevent catalyst leakage. Then, catalyst is added to the channels of the components (the hollow channel openings of the components extend longitudinally upwards along the distillation column). Depending on the column's inner diameter, more structured packing components are added to each set until the overall height reaches approximately 10 meters, completing one section of the catalytic distillation unit. This process is repeated every 0.4-1 meter upwards to add other catalytic distillation units until the design requirements of the catalytic distillation column are met.

[0033] The catalytic distillation tower using this patented technology, in the MTBE catalytic distillation reaction, when the feed contains isobutylene with a mass percentage not exceeding 2.5% and the molar ratio of methanol to isobutylene is greater than 1, the mass percentage content of isobutylene in the outlet product gas is less than 0.4%, thus achieving the goal of fully utilizing isobutylene.

[0034] The catalytic distillation tower using this patented technology, in the MTBE catalytic distillation reaction, when the feed contains isobutylene with a mass percentage not exceeding 2.5% and the molar ratio of methanol to isobutylene is less than 0.96, the mass percentage content of methanol in the outlet product gas is not greater than 0.5%, thus achieving the goal of fully utilizing methanol. Under this operating condition, the wastewater discharge of the downstream water extraction tower can be greatly reduced, which is conducive to clean production.

[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or equivalent variations to the above-disclosed technical content and apply them to other fields. However, any simple modifications, equivalent variations and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A novel catalytic distillation module comprising a structured packing assembly and a catalyst, characterized by: The structured packing assembly is composed of multiple structured packing layers which are alternately stacked, and two adjacent structured packings form a hollow channel, the catalyst is bulk packed in the hollow channel of the whole structured packing assembly, and the structured packing comprises a first perforated plate, a second perforated plate and a metal wire mesh, and the first perforated plate, the metal wire mesh and the second perforated plate are connected in sequence and tightly adhere to each other and are pressed into a corrugated plate shape.

2. A novel catalytic distillation module according to claim 1, characterized in that: The corrugation of the structured packing is a sine wave, the amplitude is 100-300 mm, the period is 400-600 mm, and the thickness is 1.5-6 mm.

3. A novel catalytic distillation module as claimed in claim 1, wherein: The holes of the first perforated plate and the second perforated plate are one of a nail hole and a bridge hole.

4. A novel catalytic distillation module according to claim 3, wherein: The opening size of the nail hole or the bridge hole is width: 0.8-10 mm and height: 0.2-1 mm, and the opening rate of the hole plate is greater than 40%.

5. A novel catalytic distillation module according to claim 4, wherein: The opening directions of the nail holes or the bridge holes on the first perforated plate and the second perforated plate are consistent.

6. A novel catalytic distillation module according to claim 1, wherein: The mesh size of the metal wire mesh is 10 mesh-200 mesh.

7. A novel catalytic distillation module as claimed in claim 1, wherein: The adhering manufacturing mode of the first perforated plate, the second perforated plate and the metal wire mesh is one of hot pressing, welding, bonding and screw connection.

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