Tube pass built-in structural member tube pass fixed bed reactor and its application

Abstract

This invention provides a tubular fixed-bed reactor with an internal structural component in the tube side. The top and bottom of the tube side are sealed with ceramic balls, and the interior of the tube side is filled with a foamed metal internal component. The foamed metal internal component has through holes, including a large hole D and a small hole d; wherein the largest diameter of the large hole D is D0. max With minimum aperture D min The ratio D max / D min ≤3, the average pore diameter Da of the large pore D is 1.0mm~5mm, and 1.0mm≤D min ≤D max ≤10mm, the maximum diameter d in the small hole d max With minimum aperture d min The ratio d max / d min ≤10, the average pore diameter da of the small hole d is 0.05mm~0.6mm, and 0.05mm≤d min ≤d max ≤1.0mm; the ratio of the average pore diameter da of the small pore d to the average pore diameter Da of the large pore D is ≤0.155. This invention improves the mass and heat transfer capacity within the reactor tubes by combining built-in structural components with catalyst particle size and reaction pressure, without increasing the catalyst bed pressure drop or sacrificing reactor production capacity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fixed tube reactor, in particular to a fixed tube reactor with internal structure in tube. BACKGROUND

[0002] Currently, the strong exothermic reactors applied in industry include slurry bed reactor, fluidized bed reactor and fixed tube reactor. Among them, the fixed tube reactor has been concerned by people due to its simple structure, small back mixing, small catalyst abrasion and easy separation of products. However, the mass transfer and heat transfer problems exist when the fixed tube reactor is used for strong exothermic reaction. In order to reduce the pressure drop of catalyst bed and the energy consumption of equipment in industrial production, the catalyst particles filled in the fixed tube reactor are usually greater than 1mm, at this time, the internal diffusion limitation of catalytic reaction becomes very important, which greatly affects the product selectivity. At the same time, due to the small ratio of the tube diameter to the catalyst diameter in the fixed tube reactor, the wall effect in the tube is serious, and combined with the poor heat conduction performance of the catalyst, the radial heat transfer in the tube is greatly limited, which easily leads to local overheating of the catalyst bed and even "flying temperature" phenomenon, which makes the active components of the catalyst sinter and the performance of the catalyst decrease.

[0003] The current methods to solve or improve these problems are to prepare catalysts with metal foam as carrier or add internal members in the tube.

[0004] CN200410096609.X loads active metal on foam metal to improve the heat conduction performance of the catalyst and reduce the pressure drop, and the obtained catalyst has the advantages of high catalytic activity and good heat conduction performance. However, the catalyst with foam metal as carrier can reduce the pressure drop, improve the heat conduction performance and eliminate the influence of internal diffusion, but due to the large porosity and low specific surface area of the foam metal, the catalyst loading capacity is low, and it is difficult to control the uniform dispersion of active components on the foam metal carrier, which is difficult for large-scale production.

[0005] CN202310311711.X fixes and connects several internal members on the inner wall of the tube of the fixed tube reactor, the internal member is a plate-shaped structure, uniformly distributed along the axial direction and extended along the axial direction, which reduces the bed pressure drop and strengthens the radial heat transfer of the reactor tube. However, the internal member fixed and connected with the wall will reduce the catalyst packing density and reduce the production capacity, and the internal member fixed in the tube of the reactor is not conducive to the loading and dismounting of the catalyst.

[0006] CN202180074473.4 describes inserting a tubular insert into a tubular reactor. This insert has an internal channel with varying diameter, and by manipulating the internal channel, the profile of the internal reaction chamber is altered, thereby improving the temperature distribution of the catalyst bed. However, in this technology, the introduced tubular insert sacrifices some reactor volume, leading to a decrease in reactor production capacity. Furthermore, since the tubular insert is mainly placed in the upstream section of the catalyst bed, which is where hot spots are prone to form, the catalyst inevitably deactivates gradually during the strongly exothermic Fischer-Tropsch synthesis reaction. At this point, the hot spots move downstream of the catalyst bed, rendering the tubular insert unable to continue its heat-removing function. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a tubular fixed-bed reactor with built-in structural components in the tube side. By combining the built-in structural components with the catalyst particle size and reaction pressure, the mass and heat transfer capacity in the reactor tube side is improved without increasing the catalyst bed pressure drop or sacrificing the reactor's production capacity.

[0008] To achieve the objectives of this invention, the following technical solution is adopted:

[0009] The present invention provides a tubular fixed-bed reactor with built-in structural components in the tube side in a first aspect. The top and bottom of the tube side of the tubular fixed-bed reactor are sealed with springs and ceramic balls. The interior of the tube side is filled with foam metal internal components. The foam metal internal components are provided with through holes, and the through holes include large holes D and small holes d.

[0010] Among them, the maximum aperture D in the large hole D max With minimum aperture D min The ratio is ≤3, the average pore diameter Da of the large pore D is 1.0mm~5mm, and 1.0mm≤D min ≤D max ≤10mm; the maximum diameter d in the small hole d max With minimum aperture d min The ratio is ≤10, the average pore diameter da of the small hole d is 0.05mm~0.6mm, and 0.05mm≤d min ≤d max ≤1.0mm; the ratio of the average pore diameter da of the small pores d to the average pore diameter Da of the large pores D is ≤0.155. In some preferred embodiments, the ratio of the total volume of the small pores d to the total volume of the large pores D in the foamed metal internal component is 0.08 to 0.8, for example, 0.10, 0.20, 0.25, 0.50, 0.60, 0.70.

[0011] In the tubular fixed-bed reactor provided by this invention, foamed metal internal components are placed in the tube side of the reactor. The foamed metal internal components have a dual-pore structure (i.e., including macropores D and micropores d), or in other words, the foamed metal internal components are a metal support composed of countless open-cell units arranged in a specific pattern. The foamed metal internal components are generally cylindrical, and the difference between their cylindrical diameter M and the inner diameter N of the tube side should generally satisfy: 0.1 ≤ NM ≤ 1 mm. This facilitates the placement of the foamed metal into the tubular reactor and allows for enhanced convection heat transfer through the small annular gaps between the foamed metal and the inner wall of the tubular reactor.

[0012] In a tubular fixed-bed reactor, the catalyst is not loaded onto the foamed metal internal components, but rather introduced into the large pores of the foamed metal internal components by gravity. This facilitates production and loading / unloading, and allows for controlled catalyst particle size. satisfy: In some specific embodiments, the minimum pore diameter D in the macropore D of the foamed metal internal component is... min Maximum particle size of catalyst particles ratio Preferred In some specific embodiments, the manufacturing methods of foam metal internal components can be sintering, electroplating, pressure casting, foaming, and 3D printing, etc.

[0013] The small pores in the foamed metal internal components of the tubular fixed-bed reactor provided by this invention are used for fluid passage, which increases the porosity of the catalyst bed, reduces the pressure drop of the catalyst bed, enhances the mass transfer capacity within the tube side of the tubular reactor, and improves product distribution. In some specific embodiments, the porosity ε of the foamed metal internal components is 0.88≤ε≤0.98, for example, 0.90, 0.93, 0.95.

[0014] In this invention, the number of open-cell foamed metal internal components packed in each tubular fixed-bed reactor is not specifically required, but for ease of loading and unloading, a number of 1 to 10 is preferred. In some specific embodiments, the volume occupied by the foamed metal internal components in the tube side of the tubular fixed-bed reactor is 0.50 to 0.95, for example, 0.60, 0.65, 0.70, 0.80, 0.85.

[0015] In some specific embodiments, in order to enhance the heat transfer effect, the ratio of the inner diameter of the tube side of the tubular fixed bed reactor to the average pore diameter Da of the macropores D in the foam metal internal components is 2 to 40, for example, 4, 5, 30, 35; preferably 6 to 20, for example, 8, 10, 15, 18.

[0016] In the tubular fixed-bed reactor provided by this invention, the thermal conductivity of the foamed metal internal components is greater than 10 W / m / K, preferably greater than 100 W / m / K; more specifically, the material of the foamed metal internal components is preferably selected from one or more of copper, iron, aluminum, titanium, stainless steel, or iron-chromium alloy. It should be noted that the material selected for the foamed metal internal components will not impair the activity of the catalyst.

[0017] In the tubular fixed-bed reactor provided by the present invention, the through holes on the foam metal internal components are circular, elliptical, pentagonal or hexagonal.

[0018] In the tubular fixed-bed reactor described in this invention, the tube dimensions (internal diameter N and height H) can be arbitrary. In some preferred embodiments, the inner diameter of the tubes is 20mm to 60mm, for example, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, and 55mm, and the internal height of the tubes is 1m to 15m, for example, 2m, 4m, 6m, 8m, 10m, 12m, and 14m. The number of tubes is not specifically limited, but is preferably 100 to 10,000.

[0019] In a second aspect, the present invention provides an application of the above-described tubular fixed-bed reactor for performing strongly exothermic reactions, such as Fischer-Tropsch synthesis and methanol synthesis.

[0020] In some specific embodiments, the conditions for the Fischer-Tropsch synthesis reaction are: pressure of 2-8 MPa, preferably 4-6 MPa; and temperature of 180-350°C, preferably 200-250°C.

[0021] In some specific embodiments, the catalyst active component of the Fischer-Tropsch synthesis reaction is one or more selected from iron, iridium, cobalt, ruthenium, rhodium, nickel, platinum, molybdenum, or tungsten; the catalyst support is selected from alumina, titanium dioxide, silica, activated carbon, zeolite, or molecular sieve. The catalyst of the present invention can be prepared by precipitation, impregnation, kneading, etc.

[0022] The above technical solution achieves the following technical effects:

[0023] The tubular fixed-bed reactor of the present invention improves the mass and heat transfer capacity within the reactor tubes by incorporating a foamed metal internal component with dual pore sizes (large pores D and small pores d) in the tubes, which is combined with the catalyst particle size and reaction pressure, without increasing the catalyst bed pressure drop or sacrificing the reactor's production capacity.

[0024] The tubular fixed-bed reactor provided by this invention improves the mass transfer capacity in the tube side, improves product distribution, and at the same time improves the heat transfer capacity in the tube side, thus improving temperature distribution. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 : schematic diagram of the packing structure of the fixed bed reactor with tubes;

[0026] Figure 2 : schematic diagram of the appearance of the foam metal inner member;

[0027] Figure 3 : schematic diagram of the microstructure of the through hole of the foam metal inner member;

[0028] Figure 4 : schematic diagram of the dual pore size distribution of the foam metal inner member;

[0029] Figure 5 : schematic diagram of the dual pore size distribution of the foam metal inner member in the Fischer-Tropsch synthesis reaction in Comparative Example 6;

[0030] In the figure, 1 is the fixed bed reactor with tubes, 2 is the porcelain ball, 3 is the foam metal inner member, 4 is the catalyst, 5 is the large hole, and 6 is the small hole. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present application, the present application will be further described below in conjunction with examples. It should be understood that the following examples are only for better understanding of the present application, and do not mean that the present application is limited to the following examples only.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0033] If the specific experimental steps or conditions are not specified in the examples, they can be operated according to the corresponding conventional experimental steps or conditions in the technical field. If the instruments used are not specified by the manufacturer, they are conventional products that can be obtained by purchase.

[0034] In the following examples, the pore size distribution and porosity are determined by mercury intrusion method.

[0035] Example 1

[0036] In this example, the inner diameter of the tube passage of the fixed bed reactor with tubes is 32 mm, and the height is 130 cm. The outer part of the tube passage is saturated water for heat removal. Three foam metal inner members are placed in the tube passage, which are made of 6061 type aluminum alloy by pressure casting method, and the thermal conductivity is 155 W / m / K, and the porosity ε is 0.90. The through hole of the foam metal inner member has a dual pore size (as shown in Figure 3 , 4 The diameter of the large hole D is 31 mm, the height is 105 mm, the average pore size Da of the large hole D is 2 mm, the average pore size da of the small hole d is 0.15 mm, and the maximum pore size D of the large hole D is 3 mm.max With minimum aperture D min The ratio D max / D min For 2, 1.5mm≤D min ≤D max ≤3mm, the maximum aperture d in the small hole d max With minimum aperture d min The ratio d max / d min =5, 0.06mm≤d min ≤d max ≤0.3mm; the volume of the foamed metal internal components occupies 0.9 of the tube side. The ratio of the total volume of the small holes to the total volume of the large holes is 0.33.

[0037] The catalyst is in spherical particle form, supported by alumina, and the active component is Co, with a Co content of 25%. The average particle size obtained by the impregnation method is... The minimum pore diameter D in the large pore D of the foamed metal internal component is 0.6 mm. min Maximum particle size of catalyst particles The ratio is 2.

[0038] Will as Figure 2 The foamed metal internal component with the above-mentioned properties, as shown, is placed in a tube array, such as... Figure 1 As shown, the catalyst is loaded into the tubular fixed-bed reactor by gravity, and the catalyst passes through and fills the large pores of the foamed metal internal components (e.g., Figure 4 As shown in the figure, if necessary, gently tap the reactor with a wooden hammer to ensure that the catalyst is packed tightly. The final catalyst packing volume is 0.77 times the macropore volume, the packing amount is 735g, and the packing height is 105cm.

[0039] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 4.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0040] Example 2

[0041] In this embodiment, the tubular fixed-bed reactor has an inner diameter of 32 mm and a height of 130 cm, with saturated water outside the tubes for heat extraction. Inside the tubes is a foamed metal internal component, made of 6061 aluminum alloy produced by pressure casting, with a thermal conductivity of 131 W / m / K and a porosity ε of 0.88. The foamed metal internal component has a dual-pore size, with a diameter of 31 mm and a height of 105 mm. The average pore diameter Da of the larger pore D is 2.5 mm, and the average pore diameter da of the smaller pore d is 0.2 mm. The largest pore diameter D in the larger pore D is... max With minimum aperture D min The ratio Dmax / D min For 1.5, 2mm≤D min ≤D max ≤3mm, the maximum aperture d in the small hole d max With minimum aperture d min The ratio d max / d min For 6, 0.05mm≤d min ≤d max ≤0.3mm; the volume occupied by the foamed metal internal components in the tube is 0.92. The ratio of the volume of the small hole to the volume of the large hole is 0.28.

[0042] The catalyst is in spherical particle form, supported by alumina, and the active component is Co, with a Co content of 25%. The average particle size obtained by the impregnation method is... The minimum pore diameter D in the large pore D of the foamed metal internal component is 0.4 mm. min Maximum particle size of catalyst particles The ratio is 3.5.

[0043] The catalyst was loaded into the foam metal macropores of the tubular fixed bed reactor by gravity. If necessary, the reactor was gently tapped with a wooden hammer to ensure that the catalyst was packed tightly. The final catalyst loading volume was 0.80 times the macropore volume, the loading amount was 770g, and the loading height was 105cm.

[0044] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 5.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0045] Example 3

[0046] In this embodiment, the tubular fixed-bed reactor has an inner diameter of 32 mm and a height of 130 cm, with saturated water outside the tubes for heat extraction. Five foamed metal internal components, made of stainless steel and fabricated using 3D printing, are embedded within the tubes. These components have a thermal conductivity of 53 W / m / K and a porosity ε of 0.95. The foamed metal internal components have a dual-pore size, with a diameter of 31 mm and a height of 105 mm. The average pore diameter Da of the large pore D is 4 mm, and the average pore diameter da of the small pore d is 0.25 mm. The largest pore diameter D among the large pores D is... max With minimum aperture D min The ratio D max / D min For 2.5, 3mm≤D min ≤D max ≤7.5mm, maximum aperture d in small hole d max With minimum aperture d min The ratio d max / dmin d < 0.6 mm; the volume of the foam metal inner member in the tube pass is 0.85. The ratio of the volume of the small holes to the volume of the large holes is 0.33. min d < 0.6 mm; the volume of the foam metal inner member in the tube pass is 0.85. The ratio of the volume of the small holes to the volume of the large holes is 0.33. max d < 0.6 mm; the volume of the foam metal inner member in the tube pass is 0.85. The ratio of the volume of the small holes to the volume of the large holes is 0.33.

[0047] The catalyst is spherical granular, the carrier is silica, the active component is Co, the Co content is 30%, the average particle size is 0.55 mm, and the catalyst is prepared by the impregnation method. The ratio of the maximum hole diameter D min to the minimum hole diameter D of the large holes D of the foam metal inner member is 4.

[0048] The above catalyst is loaded into the large holes of the foam metal inner member of the tube-pass fixed bed reactor by gravity, and the reactor is gently tapped with a wooden hammer if necessary so as to pack the catalyst, the final catalyst packing volume is 0.39 times the volume of the large holes, the packing amount is 746 g, and the packing height is 105 cm.

[0049] The Fischer-Tropsch synthesis reaction is carried out under the conditions of H2 / CO = 2, space velocity 570 h-1, reaction pressure 3.5 MPa, and reaction temperature 220°C, and the experimental results are shown in Table 1. -1 The Fischer-Tropsch synthesis reaction is carried out under the conditions of H2 / CO = 2, space velocity 570 h-1, reaction pressure 3.5 MPa, and reaction temperature 220°C, and the experimental results are shown in Table 1.

[0050] Example 4

[0051] The tube-pass fixed bed reactor used in this example has a tube pass with an inner diameter of 32 mm and a height of 130 cm, and the tube pass is externally cooled by saturated water. Five foam metal inner members made of 1070 type aluminum alloy prepared by foaming have a thermal conductivity of 226 W / m / K and a porosity ε of 0.92. The foam metal inner member has a double-pore diameter, a diameter of 31 mm, and a height of 105 mm, and the average pore diameter Da of the large holes D is 5 mm, and the average pore diameter da of the small holes d is 0.3 mm. The ratio of the maximum hole diameter D max to the minimum hole diameter D min of the large holes D is D max / D min = 2, 4 mm ≤ D min ≤ D max ≤ 8 mm, and the ratio of the maximum hole diameter d max to the minimum hole diameter d min of the small holes d is d max / d min = 3, 0.2 mm ≤ d min ≤ d max ≤ 0.6 mm; the volume of the foam metal inner member in the tube pass is 0.85. The ratio of the volume of the small holes to the volume of the large holes is 0.33.

[0052] The catalyst is in the form of spherical particles, supported by titanium dioxide, and the active component is Co, with a Co content of 25%. The average particle size obtained by precipitation method is... The minimum pore diameter D in the large pore D of the foamed metal internal component is 0.80 mm. min Maximum particle size of catalyst particles The ratio is 3.

[0053] The catalyst was loaded into the foam metal macropores of the tubular fixed bed reactor by gravity. If necessary, the reactor was gently tapped with a wooden hammer to ensure that the catalyst was packed tightly. The final catalyst loading volume was 0.39 times the macropore volume, the loading amount was 703g, and the loading height was 105cm.

[0054] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 3.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0055] Comparative Example 1

[0056] This comparative example uses a tubular fixed-bed reactor with an inner diameter of 32 mm and a height of 130 cm in the tube side, with saturated water for heat extraction outside the tube side. A catalyst is directly loaded into the tube side; specifically, the catalyst is cloverleaf-shaped, the support is alumina, and the active component is Co, with a Co content of 25%, prepared by impregnation. The catalyst length is 5–10 mm, the cross-sectional diameter is 1.6 mm, the catalyst loading is 850 g, and the loading height is 105 cm. Both the upper and lower ends of the catalyst bed are coated with... Ceramic balls are used for filling.

[0057] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The reaction was carried out at a pressure of 3.0 MPa and a temperature of 220 °C. The experimental results are shown in Table 1.

[0058] Comparative Example 2

[0059] In this comparative example, the tubular fixed-bed reactor has an inner diameter of 32 mm and a height of 130 cm, with saturated water outside the tubes for heat extraction. Two foamed metal internal components are embedded within the tubes, made of 6061 aluminum alloy produced by pressure casting. These components have a thermal conductivity of 155 W / m / K and a porosity ε of 0.90. The foamed metal internal components have a single pore size with an average pore diameter of 2 mm, a total diameter of 31 mm, and a height of 105 mm.

[0060] The catalyst is in spherical particle form, supported by alumina, and the active component is Co, with a Co content of 25%. The average particle size obtained by the impregnation method is... The thickness is 0.6 mm. The catalyst loading amount is 980 g, and the loading height is 105 cm.

[0061] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 4.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0062] Comparative Example 3

[0063] In this comparative example, the tubular fixed-bed reactor has an inner diameter of 32 mm and a height of 130 cm, with saturated water outside the tubes for heat extraction. Inside the tubes is a single foamed metal internal component, made of 6061 aluminum alloy produced by pressure casting, with a thermal conductivity of 155 W / m / K and a porosity ε of 0.90. The foamed metal internal component has a single pore size, with an average pore diameter of 0.8 mm, a diameter of 31 mm, and a height of 105 mm.

[0064] The catalyst is in the form of spherical particles, supported by titanium dioxide, and the active component is Co, with a Co content of 40%. The average particle size obtained by precipitation method is... The catalyst particles were 0.04 mm thick. The prepared catalyst particles were coated onto a metal foam using a sol-gel method, with a coating thickness of 0.1 mm. The catalyst loading amount was 165 g, and the loading height was 105 cm.

[0065] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 3.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0066] Comparative Example 4

[0067] In this comparative example, the tubular fixed-bed reactor has an inner diameter of 32 mm and a height of 130 cm, with saturated water outside the tubes for heat extraction. The tubes contain three internal foam metal components made of 6061 aluminum alloy, fabricated by pressure casting. These components have a thermal conductivity of 155 W / m / K and a porosity ε of 0.95. The foam metal internal components have a single pore size, with an average pore diameter of 2 mm, a total diameter of 31 mm, and a height of 105 mm.

[0068] The catalyst is in spherical particle form, supported by alumina, and the active component is Co, with a Co content of 25%. The average particle size obtained by the impregnation method is... The thickness is 0.3 mm. The catalyst loading amount is 1117 g, and the loading height is 105 cm.

[0069] With H2 / CO = 2 and space velocity 570 h⁻¹, -1 The Fischer-Tropsch synthesis reaction was carried out at a reaction pressure of 3.0 MPa and a reaction temperature of 220 °C. The experimental results are shown in Table 1.

[0070] Comparative Example 5

[0071] The same material, method and pore size distribution as in Example 1 were used to prepare the foam metal inner structure, and the catalyst was also the same. The difference was that the porosity ε was 0.50, which not only resulted in a catalyst loading of only 382 g in the reactor, but also resulted in a reactor production capacity of only 43.5 kg / h / m3under the same reaction conditions as in Example 1. 3 Moreover, it resulted in a significant increase in pressure drop to 491 Pa.

[0072] Comparative Example 6

[0073] A tubular fixed bed reactor was used, in which the inner diameter of the tube was 32 mm and the height was 130 cm. The tube was externally cooled by saturated water. Two foam metal inner structures were placed in the tube, which were made of 1070 aluminum alloy by pressure casting and had a thermal conductivity of 226 W / m / K and a porosity ε of 0.93. The foam metal inner structure had a double pore size, with a diameter of 31 mm and a height of 105 mm. The average pore diameter Daof the large pores D was 1.5 mm, and the average pore diameter daof the small pores d was 0.4 mm. The ratio of the maximum pore diameter D max to the minimum pore diameter D min of the large pores D was D max / D min = 5, and 1 mm ≤ D min ≤ D max ≤ 5 mm. The ratio of the maximum pore diameter d max to the minimum pore diameter d min of the small pores d was d max / d min = 3, and 0.2 mm ≤ d min ≤ d max ≤ 0.6 mm. The volume of the foam metal inner structure occupied 0.85 of the volume of the tube. The ratio of the volume of the small pores to the volume of the large pores was 0.43.

[0074] The catalyst of Example 4 was loaded into the large pores of the foam metal of the tubular fixed bed reactor, and the final catalyst loading volume was 0.3 of the volume of the large pores. The loading amount was 600 g, and the loading height was 105 cm. Under the same reaction conditions as in Example 4, the axial temperature difference was 18°C, the radial temperature difference was 13°C, and the catalyst space-time yield was 0.081 g CH2 / g catalyst / h. The larger temperature difference was due to the ratio of the average pore diameter da(0.4 mm) of the small pores d to the average pore diameter Da(1.5 mm) of the large pores D being > 0.155, which resulted in partial defects in the foam metal structure, with the small pores and the large pores partially merging (see the arrows indicating the partial merging). The heat removal capacity of the defective portion was reduced, resulting in a local temperature that was too high. Moreover, Figure 5 ​The catalyst is easy to bridge during catalyst loading process, the loading amount is reduced, the bridging will cause the gas flow to appear channeling, which affects the reaction effect, the reduction of loading amount will reduce the reactor productivity, which leads to the decrease of C 5+ space-time yield.

[0075] Table 1 comparison of test results

[0076]

[0077]

[0078] From the data in Table 1, compared with no foam metal inner member (Comparative Example 1), after adding the inner member, although the loading amount of the catalyst is slightly reduced, the utilization rate of the catalyst bed is improved due to the reduction of the axial radial temperature difference, the CO conversion rate is improved, the selectivity of C5 + in the target product is improved after the reduction of the catalyst particle, therefore, the C5 + space-time yield is increased, and the reactor production capacity is not reduced.

[0079] From Comparative Examples 2 and 4, when the particle of the catalyst is reduced, only through the single pore size foam metal and the increase of the pressure, although the axial radial temperature difference is improved, the catalyst activity and the reactor production capacity are improved, but the pressure drop of the catalyst bed is greatly increased, which is not good for the catalyst and the equipment. In Comparative Example 3, the catalyst is coated on the foam metal, the axial radial temperature difference is the smallest, the catalyst conversion rate is also high, and the pressure drop of the catalyst bed is significantly reduced, but the reactor production capacity is greatly reduced, which will affect the economic efficiency of the enterprise.

Claims

1. A fixed bed reactor of the shell-and-tube type with internal structural elements in the tube pass, characterized in that, The top and bottom of the tube passage of the fixed bed reactor are blocked by porcelain balls, the inside of the tube passage is filled with a foamed metal inner member, the foamed metal inner member is provided with through holes, and the through holes include large holes D and small holes d; Wherein, the ratio of the maximum pore diameter D max to the minimum pore diameter D min D max / D min ≤3, the average pore diameter Da of the macropore D is 1.0 mm~5mm, and 1.0 mm≤D min ≤D max ≤10 mm; The maximum diameter d in the small hole d max With minimum aperture d min The ratio d max / d min ≤10, the average pore diameter da of the small hole d is 0.05 mm~0.6 mm, and 0.05 mm≤d min ≤d max ≤1.0 mm; The ratio of the average pore diameter da of the small holes d to the average pore diameter Da of the large holes D is ≤0.155; The particle size ø of the catalyst particles filled in the fixed bed reactor satisfies: d < ø < D.

2. The fixed tube sheet reactor of claim 1, wherein, The porosity ε of the foamed metal inner member is 0.88 ≤ ε ≤ 0.

98.

3. The fixed tube sheet reactor of claim 2, wherein, The ratio of the total volume of the small holes d to the large holes D in the foamed metal inner member is 0.08-0.

8.

4. The fixed bed reactor according to claim 2, wherein The volume of the foamed metal inner member in the tube passage is 0.5-0.95, and the number of the foamed metal inner members in the tube passage of the fixed bed reactor is 1-10.

5. The fixed-tube-sheet reactor of any one of claims 1 to 4, wherein, the minimum pore diameter D of the large pores D min the ratio of the maximum particle diameter ø of the catalyst particles max 2≤D min / ø max ≤20.

6. The fixed tube sheet reactor of claim 5, wherein, the minimum pore diameter D of the large pores D min the ratio of the maximum particle diameter ø of the catalyst particles max 4 ≤ D min / ø max ≤ 12.

7. The fixed bed reactor according to claim 5, wherein The ratio of the internal diameter of the tube passage of the fixed bed reactor to the average pore diameter Da of the large holes D in the foamed metal inner member is 2-40.

8. The fixed tube sheet reactor of claim 7, wherein, The ratio of the internal diameter of the tube passage of the fixed bed reactor to the average pore diameter Da of the large holes D in the foamed metal inner member is 6-20.

9. The fixed tube sheet reactor of claim 7, wherein, The internal diameter of the tube passage is 20 mm-60 mm, and the height is 1 m-15 m.

10. The fixed tube sheet reactor of claim 7, wherein, The thermal conductivity of the foamed metal inner member is greater than 10 W / m / K.

11. The fixed-bed reactor according to claim 10, wherein The thermal conductivity of the foamed metal inner member is greater than 100 W / m / K.

12. The fixed tube sheet reactor of claim 10, wherein, The material of the foamed metal inner member is selected from one or more of copper, iron, aluminum, titanium, stainless steel, or iron-chromium alloy.

13. The fixed bed reactor according to claim 10, wherein The shape of the through holes on the foamed metal inner member is circular, oval, pentagonal, or hexagonal.

14. Use of a fixed tube bed reactor according to any one of claims 1 to 13, characterized in that Applied to strong exothermic reactions.

15. Use according to claim 14, characterized in that, The strong exothermic reaction is a Fischer-Tropsch synthesis reaction or a methanol synthesis reaction.

16. Use according to claim 15, characterized in that, The conditions of the Fischer-Tropsch synthesis reaction are: a pressure of 2-8 MPa and a temperature of 180-350℃.

17. Use according to claim 16, characterized in that, The conditions of the Fischer-Tropsch synthesis reaction are: a pressure of 4-6 MPa and a temperature of 200-250℃.

18. The use according to claim 16, characterized in that, The active component of the catalyst of the Fischer-Tropsch synthesis reaction is one or more of iron, iridium, cobalt, ruthenium, rhodium, nickel, platinum, molybdenum, or tungsten. The carrier of the catalyst is selected from aluminum oxide, titanium dioxide, silicon dioxide, activated carbon, zeolite, or molecular sieve.

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