CN111036151B

CN111036151B - Slurry bed reactor with multi-stage perforated structure distribution plate

Info

Publication number: CN111036151B
Application number: CN201911394927.7A
Authority: CN
Inventors: 赵陆海波; 彭词; 唐志永
Original assignee: Shanghai Ruicheng Carbon Energy Technology Co ltd
Current assignee: Shanghai Ruicheng Carbon Energy Technology Co ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2022-02-11
Anticipated expiration: 2039-12-30
Also published as: CN111036151A

Abstract

The invention provides a slurry bed reactor, which comprises a distribution plate, wherein the distribution plate comprises a plurality of primary perforations and a plurality of secondary perforations, the primary perforations are distributed in the form of two to twelve spiral arms relative to the geometric center of the plate, the secondary perforations are distributed in each spiral arm, and one to six secondary perforations associated with each primary perforation are arranged near each primary perforation.

Description

Slurry bed reactor with multi-stage perforated structure distribution plate

Technical Field

The invention belongs to the field of chemical equipment devices, and particularly relates to a slurry bed reactor, wherein a distribution plate of the slurry bed reactor is provided with a specially designed multistage perforated structure, preferably a fractal perforated structure.

Background

In the fields of chemical industry, biological engineering, environmental protection and the like, processes such as chemical reaction, biological engineering cultivation and the like are often required to be carried out in a multiphase reaction system in which gaseous, liquid and solid materials exist simultaneously, specific examples of such processes may include biological fermentation, wastewater treatment, tail gas treatment, chemical synthesis, and the like, the gaseous and liquid materials used therein may include various reactants and process aids, the solid paste may be either a reactant, a culture substrate, or a reaction catalyst or other process aids, these biological or chemical processes are usually carried out using various three-phase reactors, such as stirred bubble-tank reactors, bubble column reactors, plate reactors, packed column reactors, tubular reactors, jet reactors, etc., of which one of the most important is a bubble reactor, e.g. a slurry bed reactor.

The major problems with slurry bed reactors are that the uniformity of the overall material concentration and flow velocity distribution is difficult to control, unavoidable and difficult to control turbulence, back-mixing, etc. may occur locally, and that dead zones may also be present, the above problems of uniform mass transfer and uniform heat transfer having a great adverse effect on the quality of the process product and on the routine operation and maintenance of the slurry bed. In order to overcome the above problems, a great deal of research has been conducted on slurry bed reactors so far, and the specific means adopted is not limited to arranging a greater number of nozzles, baffles, heat exchange pipes, reflux circulation structures and the like at different positions in the reactor so as to improve the material circulation and energy exchange at various positions in the slurry bed reactor. Although the above-mentioned improvement can alleviate the existing problems to some extent, these additional components can significantly increase the complexity of the design and operation of the slurry bed reactor, resulting in a substantial increase in capital and routine maintenance costs, and these newly added components can introduce many new blocking points inside the reactor, and even possibly bring new adverse effects to the mass and heat transfer in the reactor, and bring new problems while solving the original problems. The continuing development of this concept in accordance with the prior art has resulted in the fact that technicians are required to monitor and adjust more and more parameters while operating the plant, the complexity of the reaction system is increasing and the improvement in overall mass and heat transfer is in fact limited.

In order to solve the above problems, the inventors of the present application have conducted extensive studies and found that by specially designing the structure of the distributor, the overall uniformity of mass and heat transfer in the slurry bed reactor can be significantly improved, the contact and interaction (chemical reaction, biochemical reaction, biological action, physical adsorption, etc.) between the gas, liquid and solid phases can be effectively improved, the back mixing and dead zone problems can be eliminated or greatly reduced, and the overall efficiency of the system can be significantly improved by adopting a significantly simplified reactor design without adopting additional components and structures such as nozzles, baffles, return pipes, etc., which are conventionally used in the prior art. In addition, the inventor also finds that the heat transfer and mass transfer effects of the system can be further improved by additionally adopting a special heat exchange pipe arrangement mode in the reactor. Based on the research results, the technical purpose of the invention is realized.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a slurry bed reactor having a multi-stage perforated structured distribution plate, the slurry bed reactor comprising a housing, an inlet at the bottom of the housing, an outlet at the top of the housing, a distribution plate in an interior space enclosed by the housing, and a separator in the interior of the space above the distributor, characterized in that:

the distribution plate including a first set of perforations including a plurality of primary perforations and a second set of perforations including a plurality of secondary perforations,

a plurality of primary perforations in the first group of perforations are distributed in a form of two to twelve spiral arms relative to the geometric center of the plate, a connecting line of the geometric centers of the primary perforations included in each spiral arm forms a nonlinear spiral line extending from the geometric center of the distribution plate to the edge of the distribution plate, and the aperture of the primary perforations in the same spiral arm is 0.5-10 mm, preferably 0.5-5 mm;

a plurality of secondary perforations of the second set of perforations are distributed in each spiral arm, one to six associated secondary perforations are arranged in the vicinity of each primary perforation, and the ratio of the aperture of each primary perforation to the aperture of each associated secondary perforation is 3:2 to 10: 1. According to a preferred embodiment, the apertures of the primary perforations in the same radial arm are gradually larger and then gradually smaller in the direction from the geometric center of the distribution plate toward the edge of the distribution plate.

According to a second aspect of the present invention there is provided the use of a slurry bed reactor as described above, for a process selected from the group consisting of: physical adsorption processes, such as automobile exhaust treatment and plant exhaust treatment; chemical reactions such as fischer-tropsch synthesis, hydrogenation, oxidation, chlorination, sulfonation, alkylation, carbonylation, esterification, transesterification, catalytic isomerization, and chemical absorption of the off-gas; bioengineering, such as biological fermentation, bacterial culture, algae culture, etc.

In the following detailed description section, the structural design of the slurry bed reactor developed in the present application is described with reference to the accompanying drawings.

Drawings

The drawings show some of the designs of the present invention and prior art.

Fig. 1 shows the general structure of a slurry bed reactor.

Fig. 2A-2D illustrate the construction of a distribution plate designed according to some embodiments of this invention.

Fig. 3A-3B illustrate the construction of a distribution plate designed according to the prior art, wherein the perforations of the various levels are arranged in a uniform pattern.

Fig. 4 shows a structure of a distribution plate according to another embodiment of the present invention.

Fig. 5 and 6 show the structure of heat exchange tubes designed according to two different embodiments of the present invention, respectively.

Fig. 7A and 7B show graphical diagrams of the functions that generate the perforation pattern.

Detailed Description

The "ranges" disclosed herein are in the form of lower and upper limits. There may be one or more lower limits, and one or more upper limits, respectively. The given range is defined by the selection of a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges that can be defined in this manner are inclusive and combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, ranges of 60-120 and 80-110 are listed for particular parameters, with the understanding that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.

In the present invention, unless otherwise stated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "0 to 5" indicates that all real numbers between "0 to 5" have been listed herein, and "0 to 5" is only a shorthand representation of the combination of these numbers.

The term "two" as used herein means "at least two" if not otherwise specified.

In the present invention, all embodiments and preferred embodiments mentioned herein may be combined with each other to form a new technical solution, if not specifically stated.

In the present invention, all the technical features mentioned herein and preferred features may be combined with each other to form a new technical solution, if not specifically stated.

In the present invention, all the steps mentioned herein may be performed sequentially or randomly, if not specifically stated, but preferably sequentially. For example, the method comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, and may also comprise steps (b) and (a) performed sequentially. For example, reference to the process further comprising step (c) means that step (c) may be added to the process in any order, for example, the process may comprise steps (a), (b) and (c), may also comprise steps (a), (c) and (b), may also comprise steps (c), (a) and (b), etc.

In the present invention, the term "comprising" as used herein means either an open type or a closed type unless otherwise specified. For example, the term "comprising" may mean that other components not listed may also be included, or that only listed components may be included.

In the present invention, when describing the spatial relationship of a particular component or object relative to other components or objects, the terms "inner", "outer", "above", "below", and the like, are used to indicate that the former is located inside, outside, above or below the latter, which may be in direct contact with each other, may be separated by a certain distance, or may be separated by a third component or object.

It is emphasized here that the embodiments shown in the figures and described below are merely exemplary embodiments of the invention, to which the scope of protection of the invention is not limited. The scope of the invention is defined by the claims and may include any embodiments within the scope of the claims, including but not limited to further modifications and alterations to these embodiments.

Some preferred slurry bed reactors are hereinafter characterized primarily on the basis of the fischer-tropsch synthesis reaction for mass and heat transfer, but it is emphasized here that the use of the slurry bed reactor of the invention is not limited to only the fischer-tropsch synthesis reaction, but can also be used in any other process that can be carried out in a three-phase system, and that it also allows these other processes to gain technical improvements and gains from mass and heat transfer, examples of which include physical adsorption processes, such as automobile exhaust gas treatment and plant off-gas treatment; chemical reactions such as hydrogenation, oxidation, chlorination, sulfonation, alkylation, carbonylation, esterification, transesterification, catalytic isomerization, and chemical absorption of the off-gas; bioengineering, such as biological fermentation, bacterial culture, algae culture, etc.

Fig. 1 shows the general structure of a slurry bed reactor comprising a housing 1 and, in order from bottom to top, an inlet 5 at the bottom, a distributor 2 (in the form of a distribution plate in the figure), a separator 4 and an outlet 6 at the top. According to one embodiment, the slurry bed reactor is pre-loaded with solid material, or with a mixture of solid and liquid, before the start of the reaction, and liquid and/or gaseous material is fed in at the start of the reaction from the lower inlet 5, preferably gaseous material is fed in through the lower inlet 5. After the gaseous material or the mixture of the gaseous material and the liquid paste is fed from the inlet 5, the gaseous material or the mixture of the gaseous material and the liquid paste is dispersed into bubbles or liquid droplets with smaller sizes under the action of the distribution plate 2, enters the inner space of the reactor above the distribution plate 2 with a specific size distribution and flow pattern, and the gas, liquid and solid materials in the inner space contact with each other while ascending, so that the target reaction, such as the Fischer-Tropsch reaction, is generated to generate the target products, such as hydrocarbons with different chain lengths. The material then rises further and the target product is separated out by the separator 4 and is transported out of the top outlet 6 to a subsequent process or storage vessel, while other materials than the target product (e.g. gaseous and liquid reaction materials, solid materials, etc.) can be returned to the inner space of the reactor for further reaction, and a part of the separated materials (e.g. by-products) can be transported out of the reactor via a separate discharge mechanism and discharged directly or after-treatment.

The housing is intended to enclose an inner space surrounding the reaction chamber and may be, for example, a stainless steel housing. In the reactor shown in fig. 1, the cross-sectional diameter of the upper portion of the shell is larger than the cross-sectional diameter of the lower portion, but the scope of the invention is not limited thereto and the reactor shell of the present application may have any desired shape and size, for example, may have the same cross-sectional diameter from top to bottom. According to a preferred embodiment of the invention, the reactor has a longitudinal (axial) height of 5 to 50 meters, for example 10 to 40 meters, preferably 20 to 35 meters. According to another preferred embodiment of the invention, the reactor has the same cross-sectional diameter along the longitudinal axis from top to bottom. According to another preferred embodiment of the invention, the reactor has a smaller cross-sectional diameter along the longitudinal axis at the height of the lower part 1/5 to 4/5, such as 1/3 to 1/2, for example an internal diameter of 0.5 to 10 meters, such as 0.8 to 8 meters, or 0.9 to 7 meters, or 1 to 5 meters, or 1.2 to 3 meters, or 1.5 to 2 meters, or 1.6 to 1.8 meters, since the reaction of the gas-liquid-solid three phases takes place mainly in this part, which can be referred to as "three-phase reaction part"; the three-phase reaction section has a larger cross-sectional diameter above it, for example an internal diameter of 0.8-15 meters, for example 1-12 meters, or 1.5-10 meters, or 1.8-8 meters, or 2-6 meters, or 1.5-5 meters, or 1.6-4 meters, or 1.7-3 meters, since this portion is predominantly gas phase material and recovered liquid and solid material descends back to the three-phase reaction section via this portion, and this portion may therefore be referred to as "gas phase" or "downcomer". According to a preferred embodiment of the invention, the liquid level in the reactor substantially coincides with the upper limit of said "three-phase reaction section", so that the height of the "three-phase reaction section" can be defined in the following specific experiments by the "slurry bed liquid level".

In the embodiment shown in fig. 1, the inlet is simply connected to one pipe, but it may be further modified as needed. For example, one or more devices selected from the group consisting of: valves, flow meters, heat exchange devices, baffles, flanges, threads, pins, fins, and any combination thereof. In addition, a plurality of inlets may be provided at the bottom of the reactor, and the plurality of inlets may be provided at the bottom of the reactor in any manner, for example, uniformly at the periphery or at the central position of the bottom of the reactor, and may be in the form of simple openings or nozzles.

Above the inlet there is a distribution plate having a specially designed pattern of perforations therein, specifically the distribution plate comprises a first set of perforations comprising a plurality of primary perforations and a second set of perforations comprising a plurality of secondary perforations. According to a preferred embodiment of the present invention, the distribution plate includes a third set of perforations including a plurality of tertiary perforations. In accordance with another preferred embodiment of the present invention the distribution plate includes a third set of perforations including a plurality of tertiary perforations. According to another preferred embodiment of the present invention, the distribution plate comprises a fourth set of perforations comprising a plurality of quaternary perforations.

The preferred embodiments of the present invention described below with reference to the drawings all include a one-stage to four-stage perforated design.

Referring to fig. 2A of the present application, three radial arms are shown that are centered symmetrically with respect to the geometric center of the distribution plate. Each radial arm is composed of a first group of through holes to a fourth group of through holes, the connecting line of the geometric centers of the primary through holes in the first group of through holes forms a nonlinear spiral line extending from the geometric center of the distribution plate to the edge of the distribution plate, and the aperture of the primary through holes in the same radial arm is 0.1-20 mm, such as 0.2-18 mm, 0.5-15 mm, 0.6-14 mm, 0.7-13 mm, 0.8-12 mm, 0.9-11 mm, 1-10 mm, 2-9 mm, 3-8 mm, 4-7 mm, 5-6 mm, or in the numerical range formed by combining any two of the above numerical values. Throughout the present invention, the primary perforations, secondary perforations, and optionally tertiary and quaternary perforations, have a shape selected from: circular, elliptical, oval, diamond, rounded diamond, square, rounded square, rectangular, rounded rectangle, irregular, and combinations thereof. When the perforations are circular, the aperture is the diameter of the circle. When the perforations are of any other shape than circular, the aperture means having a cross-sectional area corresponding to the perforationsThe diameter of an "equivalent circle" of the same area. It is noted here that the "equivalent circle" does not actually exist, but is used to scale an imaginary circle of the aperture. For example, assuming that the perforations are rectangular with a length of 2mm × 1mm, the aperture of the perforations is 2mm in cross-sectional area²The diameter of the "equivalent circle" of (2) can be easily converted. According to a preferred embodiment, the primary, secondary, tertiary and quaternary perforations are all circular.

According to the preferred embodiment of the present invention, the apertures of the primary perforations in the same radial arm become gradually larger and smaller in the direction from the geometric center of the distribution plate to the edge of the distribution plate. Preferably, the aperture of any one primary perforation (including the largest primary perforation and the smallest primary perforation) is 20% to 200% of the average aperture compared to the average aperture of all primary perforations in the same radial arm. It is particularly pointed out here that by primary perforations of the first set of perforations is mainly meant that these primary perforations do not have sharp abrupt changes in curvature during their extension along the central connecting line (hereinafter simply referred to as "primary perforation central connecting line"). In the present specification, the term "abrupt change in curvature" means that the rate of change in curvature at any one site is not more than 50%, for example not more than 40%, or not more than 30%, or not more than 20%, or not more than 10%.

The secondary perforations in the second set of perforations are distributed in each spiral arm, one to six secondary perforations are arranged in the vicinity of each primary perforation, and the relation means that the included angle between the connecting line of the centers of the secondary perforations and the center of the corresponding primary perforation and the tangential direction of the center of the primary perforation on the connecting line of the centers is 10-170 degrees, such as 10-90 degrees, and the specific included angle between the centers of the secondary perforations and the center of the primary perforation is 110-300 percent, such as 120-200 percent (namely, arranged in the vicinity of the primary perforation), and if the secondary perforations and the primary perforations satisfy the relation, the secondary perforations and the primary perforations are considered to be in "relation". If the secondary perforations do not satisfy the above relationship with the primary perforations, the secondary perforations are considered not "associated" with the primary perforations. According to a preferred embodiment, the ratio of the aperture of each primary perforation to the aperture of each secondary perforation associated therewith is between 3:2 and 10: 1.

According to a preferred embodiment of the present invention, the distribution plate comprises a third set of perforations, wherein a plurality of tertiary perforations are distributed in each spiral arm, and one to six tertiary perforations are associated with each secondary perforation in the vicinity of the third set of perforations. The relationship between the secondary perforations and the tertiary perforations is similar to that between the secondary perforations and the primary perforations, that is, the term "the secondary perforations are associated with the tertiary perforations" means that the line connecting the center of the tertiary perforation and the center of the corresponding secondary perforation forms an angle of 10 ° to 170 °, for example, 10 ° to 90 °, with the tangential direction of the center of the secondary perforation on the line connecting the centers, and the center of the tertiary perforation is specifically 110% to 200% of the radius length of the secondary perforation (i.e., is disposed "near" the secondary perforation), and the tertiary perforation and the secondary perforation are considered to be "associated" if they satisfy the above relationship. If the relationship above is not satisfied by the tertiary and secondary perforations, the tertiary perforation is considered not "associated" with the secondary perforation. According to a preferred embodiment, the ratio of the aperture of each secondary perforation to the aperture of each associated tertiary perforation is between 3:2 and 10: 1.

According to a preferred embodiment of the present invention, the distribution plate comprises a fourth set of perforations, wherein a plurality of fourth-level perforations are distributed in each spiral arm, and one to six fourth-level perforations are associated with each fourth-level perforation in the vicinity of each third-level perforation. The relationship between the tertiary perforations and the quaternary perforations described herein is similar to the relationship between the secondary perforations and the primary perforations described above, that is, by "tertiary perforations are associated with quaternary perforations" it is meant that the line connecting the center of the quaternary perforations to the center of the corresponding tertiary perforations makes an angle of 10 ° to 170 °, for example 10 ° to 90 °, with the tangential direction of the center of the tertiary perforations on the line connecting the centers, and that the radius between the center of the quaternary perforations and the center of the tertiary perforations is in particular 110% to 200% (i.e. disposed "near" the tertiary perforations), and that the quaternary perforations and the tertiary perforations are considered "associated" if they satisfy the above relationship. If the relationship above is not satisfied by the four-level perforations and the three-level perforations, then the four-level perforations and the three-level perforations are not considered to be "associated". According to a preferred embodiment, the ratio of the aperture of each tertiary perforation to the aperture of each associated quaternary perforation is between 3:2 and 10: 1.

Each individual primary perforation is progressively smaller in pore size than the secondary, tertiary and quaternary perforations with which it is "associated" according to the above definition. However, it is not necessary to follow such a relationship that the aperture becomes smaller in steps between each perforation and the next perforation that is "not associated" therewith.

According to one embodiment of the present application, the primary perforations, secondary perforations, and optionally tertiary and quaternary perforations, have a shape selected from the group consisting of: circular, elliptical, oval, diamond, rounded diamond, square, rounded square, rectangular, rounded rectangle, irregular, and combinations thereof. According to a preferred embodiment of the invention, the primary perforations, the secondary perforations, and optionally the tertiary and quaternary perforations, have the same shape, for example circular.

According to an embodiment of the present invention, the distribution plate includes one to twelve cantilevers, such as one cantilever, two cantilevers, three cantilevers, four cantilevers, five cantilevers, six cantilevers, seven cantilevers, eight cantilevers, nine cantilevers, ten cantilevers, eleven cantilevers, or twelve cantilevers.

According to an embodiment of the present invention, the total area percentage (also called the open area ratio) of all the perforations in the distribution plate is 10-40% based on the total area of the distribution plate, and may be, for example, within a range of values where any two of the following values are combined with each other as end values: 10%, 10.5%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%.

According to one embodiment of the present application, in each radial arm, the primary perforations, the secondary perforations, and optionally the tertiary and quaternary perforations collectively form a multi-level fractal non-uniform spiral pattern. Preferably, the overall distribution pattern of all perforations in each spiral arm is a multi-level fractal non-uniform spiral pattern defined at least in part by Julia set fractal.

According to a preferred embodiment of the invention, the Julia set is obtained from a number of iterations as follows:

f_c(z)＝z²+c

a detailed schematic of this function is shown in fig. 7A and 7B. FIG. 7A shows f (z) ═ z²Case of time | z | ═ 1, if z is within J, iteration f^k(z) → 0, if z is outside J, | f^k(z) | → ∞. The applicant of the present application regards the function f (z) z shown in fig. 7A²Adding perturbation parameter c to obtain function f_c(z)＝z²+ c, whereby the corresponding function pattern can be changed by iteration as shown in fig. 7B. Where z is a number satisfying f^kPoint z ∈ C boundary, f → ∞ of (z) → ∞^k(z) the kth iteration f (f (·. f (z). cndot.)) of z, taking some z₀The value as the initial value may usually take 0, where c is a complex number a + bi, and a has a value in the range of [ -1,1 [ ]]For example, a can be within a range consisting of any two of the following values: -0.99, -0.95, -0.90, -0.87, -0.85, -0.80, -0.77, -0.75, -0.70, -0.68, -0.65, -0.60, -0.58, -0.55, -0.50, -0.48, -0.45, -0.40, -0.35, -0.32, -0.25, -0.22, -0.20, -0.18, -0.15, -0.12, -0.10, -0.08, -0.03,0.02,0.05,0.08,0.10,0.12,0.14,0.15,0.18,0.20,0.22,0.25,0.28,0.30,0.32,0.35,0.40,0.42,0.45,0.48,0.50,0.52,0.55,0.58,0.60,0.62,0.65,0.68,0.70,0.72,0.75,0.78,0.80,0.82,0.85,0.88,0.90,0.92,0.95,0.98. Most preferably, a is-0.77. The value range of b is [ -1,1 [ ]]For example, b can take the following valuesWithin the range of any two values: -0.99, -0.95, -0.90, -0.87, -0.85, -0.80, -0.77, -0.75, -0.70, -0.68, -0.65, -0.60, -0.58, -0.55, -0.50, -0.48, -0.45, -0.40, -0.35, -0.32, -0.25, -0.22, -0.20, -0.18, -0.15, -0.12, -0.10, -0.08, -0.03,0.02,0.05,0.08,0.10,0.12,0.14,0.15,0.18,0.20,0.22,0.25,0.28,0.30,0.32,0.35,0.40,0.42,0.45,0.48,0.50,0.52,0.55,0.58,0.60,0.62,0.65,0.68,0.70,0.72,0.75,0.78,0.80,0.82,0.85,0.88,0.90,0.92,0.95,0.98. Most preferably, b is 0.22. The number of iterations k is 5-200, for example k may be in the range of any two values: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195. Most preferably, k is 150. Theoretically, the image formed can be changed correspondingly through different parameter selections. According to a preferred embodiment of the invention, the function iteration is performed based on the above-mentioned parameter selection to obtain a corresponding function image, which corresponds to the pattern of the perforations in any one of the radial arms of the distribution plate according to the invention. More specifically, the relative position and aperture of each (primary, secondary, optional tertiary, and optional quaternary) perforation is determined according to the functional pattern described above, generally forming a pattern of perforations in one radial arm, which is rotated as necessary relative to the geometric center of the distribution plate to obtain the overall pattern of the present invention having from 2 to 12 radial arms.

According to a preferred embodiment of the invention, 2 to 12 radial arms are provided in the distribution plate, the perforation patterns of the various stages in each radial arm being obtained on the basis of Julia sets as described above. Fig. 2A-2D illustrate multi-stage perforation designs including three, four, five, and six radial arms, respectively.

Without wishing to be bound by any particular theory, the applicant has found in his research that by using the above-described perforation design, in particular the fractal perforation structure design based on Julia set, the uniformity of mass and heat transfer in the whole slurry bed reactor can be significantly improved without adding any additional devices (e.g. spray heads, nozzles, material withdrawal pipes, etc.). The most important technical improvement is that, according to the general knowledge of the prior art, it is usually intended to make the perforations on the distribution plate have a distribution pattern as uniform as possible, for example, fig. 3A and 3B respectively show the case where perforations having the same total area (aperture ratio) are uniformly distributed in the distribution plate in different ways, as is the case with the design idea of the prior art. The present invention, in contradistinction to this common general knowledge, employs a non-uniform distribution of a particular pattern of perforations in the distribution plate, particularly where the perforations in each of the arms are arranged in a non-uniform manner, and as a result, it has been unexpectedly discovered that such non-uniformity actually achieves a significant improvement in the uniformity of mass and heat transfer in the system, thereby significantly reducing the effects of adverse back-mixing, dead zones, etc. in the reaction system, ultimately resulting in a significant improvement in the selectivity of the desired product. Fig. 4 shows another way of arranging the perforations in a manner other than Julia collection according to an embodiment of the invention, wherein the perforations of each stage in each radial arm are each arranged according to the equation f (x) ASin (ω x), where a has a value greater than 0 and smaller than the reactor radius, here 0.5, and ω has a value k pi, here pi.

In order to effectively compare the influence of the perforation pattern distribution on the mass and heat transfer, excluding the influence of the total area of the perforations, the distribution plates shown in fig. 2A to 2D, 3A to 3B and 4 of the present invention have the same diameter and thickness themselves, and are installed at the exact same position in the reactor. Fig. 3A shows a design with two-stage perforations evenly distributed in the distribution plate, and the total area of all perforations shown in fig. 3A is the same as the total area of the perforations of fig. 2D of the present invention. Fig. 3B shows a two-stage design of perforations in a distribution plate in the form of three straight radial arms, where the total area of all perforations shown in fig. 3B is the same as the total area of perforations (open area ratio) of fig. 2A of the present invention. As described above, FIG. 4 shows a pattern in which four perforation arms are arranged in a manner other than Julia's collection, and the total area of all the perforations in the perforation pattern shown in FIG. 4 is the same as the total area of the perforations (open area ratio) of FIG. 2B of the present invention.

In the internal space above the distribution plate, especially below the liquid level of the slurry bed, the gas-liquid-solid three-phase materials contact each other and react, such as Fischer-Tropsch reaction. According to a preferred embodiment, a heat exchanger is arranged within the "three-phase reaction section", said heat exchanger comprising at least two heat exchange tubes which extend in a spiral form. The heat exchange tube may be made of a material selected from the group consisting of: stainless steel, copper, iron, ceramic, glass, aluminum, and the like. According to a preferred embodiment, as shown in FIG. 5, the at least two heat exchange tubes are arranged in a DNA-like double helix shape extending around the longitudinal axis of the reactor. The two heat exchange tubes may not be in fluid communication with each other or may be in fluid communication with each other. In the heat exchange tube structure shown in fig. 5, a plurality of transverse tubes are arranged between two heat exchange tubes, and the transverse tubes may be made of the same or different materials as the two heat exchange tubes, and are preferably made of the same material. These transverse tubes may or may not be in fluid communication with the heat exchange tubes, preferably not. During the reaction, a heat exchange fluid (e.g., water, heat exchange oil) flows through the heat exchange tubes, and the temperature in the reactor is finely adjusted. In the prior art, a U-shaped or snake-shaped heat exchange tube is generally adopted, and a single heat exchange tube is generally adopted. According to a preferred embodiment of the present invention, the heat exchange tube of the DNA double helix shape exhibits a uniform helix diameter, as viewed from the top of the reactor, which is 10 to 95%, for example, 15 to 90%, or 20 to 80%, or 15 to 70%, or 20 to 60%, or 15 to 50%, or 20 to 40%, or 20 to 30%, or a range of any two of the above values, of the inner diameter of the reactor.

According to another preferred embodiment of the present application, as shown in fig. 6, three heat exchange tubes are provided in the reactor, which are arranged in the form of concentric spirals extending along the longitudinal axis of the reactor, and the transverse dimension of each spiral becomes progressively larger in the direction from the bottom to the top. According to a preferred embodiment, the transverse diameter of each turn of the helix is increased by 2% to 50%, for example 5% to 20%, relative to the transverse diameter of the immediately underlying turn of the helix. According to a preferred embodiment, each heat exchange tube comprises five to fifty turns of the helix, for example eight to forty turns of the helix, or ten to thirty turns of the helix, or fifteen to twenty-five turns of the helix, or twenty turns of the helix. According to a preferred embodiment of the present invention, each turn of the spiral of the heat exchange tube has the same inner diameter of the heat exchange tube as compared with the spirals above and below the heat exchange tube, and the interval between the heat exchange tubes is also maintained constant. According to a preferred embodiment of the present invention, each of the helically shaped heat exchange tubes exhibits a decreasing helical diameter, as seen from a top view of the reactor, wherein the diameter of the largest one turn of the helix is 10-95%, such as 15-90%, or 20-80%, or 15-70%, or 20-60%, or 15-50%, or 20-40%, or 20-30%, or a range of any two of the above values, of the inner diameter of the reactor. The diameter of the largest spiral of each inner spiral in top view is 50-90%, such as 60-80%, or 65-75% of the diameter of the spiral of its immediately adjacent outer spiral.

Without wishing to be bound by any particular theory, the inventors have surprisingly found through research that the arrangement of the heat exchange tubes not only can bring about improvement of heat transfer efficiency, but also can simultaneously realize improvement of mass transfer due to specific structural design, thereby reducing the influence of adverse factors such as adverse back mixing, dead zones and the like in a reaction system, and finally showing further improvement of selectivity of the target product.

The upper part of the inner space of the reactor is provided with a separator to which the gaseous stream, which is entrained with a part of the liquid and solids, rises after the reaction has taken place. The separator 30 may be any separator known in the art that can be used to perform three phase gas, liquid, and solid separations, preferably a cyclone separator. According to a preferred embodiment, the separator further comprises downstream thereof a baffle, a demister or the like. After the separation of the liquid and solids in the separator, the gaseous material rises from the separator through a baffle and is passed through a demister to remove the remaining foam, i.e. a small amount of residual liquid, and is then discharged from the reactor top outlet 6. While the liquid and solid components separated in the separator flow back down into the slurry. According to a preferred embodiment, the separator is a cyclone separator comprising a dipleg, the lower end of which extends below the liquid level in the reactor. In a preferred embodiment of the invention, the reactor according to the invention comprises 1 to 20, preferably 1 to 10, separation devices 4, which separation devices 4 are evenly distributed around the inner wall below the partition.

In the embodiment shown in fig. 1, the outlet 6 is simply connected to one pipe, but may be further modified as required. For example, one or more devices selected from the group consisting of: valves, flow meters, heat exchange devices, baffles, flanges, threads, pins, fins, and any combination thereof.

In addition to the apparatus shown in FIG. 1, the reactor of the present invention may also include other apparatuses as needed, for example: a settling tube, which may be a ratio pipe having an inner diameter smaller than the diameter of the cross-section of the reactor, disposed in the inner space of the reactor in a direction parallel to the longitudinal axis of the reactor for guiding the material to settle down in the tube; a material circulation system comprising a circulation inlet located on the wall of the shell in the middle of the reactor, a circulation pipe located outside or inside the shell of the reactor, and a circulation outlet located at the bottom of the reactor (but above the inlet at the bottom of the shell), the circulation system being adapted to draw a portion of the material in the reactor from the circulation inlet during the course of the reaction and transport it via the circulation pipe to the circulation outlet at the bottom, thereby establishing an additional circulation of the material in the reactor to promote mass and heat transfer; a heating/cooling device; temperature/pressure/flow rate sensors; flow control members such as baffles, flow directing plates, fins, stirring blades, and the like. One or more of the above-mentioned means may be additionally added to the slurry bed reactor as needed, but according to a preferred embodiment of the present invention, the desired superior properties of mass and heat transfer are achieved without the use of the above-mentioned other means by the preferred design of the distribution plate.

Any two or more of the above-described embodiments of the present invention may be combined with each other arbitrarily, and such combinations are also included in the present general inventive concept.

Examples

Preferred embodiments of the present invention are specifically exemplified in the following examples, but it should be understood that the scope of the present invention is not limited thereto.

In the following examples and comparative examples, a plurality of reaction systems were constructed, and the influence of the reaction systems on the Fischer-Tropsch reaction was examined by designing distribution plates and heat exchangers therein.

In the following examples and comparative examples, the slurry bed reactor shown in FIG. 1 was used, the reactor having a casing made of stainless steel, a "three-phase reaction part" for receiving the slurry thereunder, the height from the distribution plate to the liquid surface being 15 m, the inner diameter of the reactor in the three-phase reaction part being 2m, the total axial height of the reactor being 35 m, 1 gas-liquid/solid cyclone separating means being disposed at the top of the reactor, and the three-phase reaction part in the reactor being previously charged with 60 tons of liquid paraffin and 3 tons of cobalt-based catalyst (the chemical formula of which is Co) having the chemical formula of 60 tons before the start of the reaction₂C, according to DOI: 10.1038/nature 19786), the catalyst being present in the slurry in an amount of 5 wt%.

At the start of the reaction, the raw material gas was made to flow at 0.2 m.s^-1Is fed into the reactor from an inlet at the bottom of the reactor, so that 7500 standard square feed gas comprising 49% by volume of hydrogen, 49% by volume of CO and 2% by volume of nitrogen is fed into the reactor per hour. The pressure in the reactor was maintained at 1.0MPa and the temperature at 220 ℃ during the reaction. The raw material gas input from the inlet is subjected to gas distribution through the distribution plate, and then rises in a slurry bed layer in a dispersed manner, bubbles drive slurry in the bed layer and a catalyst to flow upwards together to reach the surface of the slurry, in the process, the raw material gas, liquid paraffin and the catalyst are contacted with each other, the raw material gas is subjected to Fischer-Tropsch synthesis reaction under the action of the catalyst to generate wax and hydrocarbon oil, and meanwhile, part of byproduct light hydrocarbons are generated. The gaseous material is separated from the surface of the slurry and carriedThe mixture of product and by-product was taken out of the outlet after separation by a cyclone with a portion of droplets and fine solids rising, and characterization and analysis of the product were carried out using a gas chromatograph model GC-14C from Shimadzu, and the results are summarized in Table 1. The majority of the liquid and solid material moves laterally at the slurry surface towards the reactor housing, descends along the housing back to the distributor plate, repeats the slurry bed reaction process described above, and the liquid and solids recovered at the cyclone return to the level of the slurry bed via the blanking leg of the cyclone, also moves laterally towards the reactor housing, descends along the housing back to the distributor plate, repeats the slurry bed reaction process described above.

The different designs of the comparative examples and examples of the invention are as follows:

example 1

The slurry bed reactor of example 1 was designed in the manner as described above, using a distribution plate (opening rate of 16.11%) as shown in fig. 2A comprising three radial arms, which was disposed at the lower part of the reactor as shown in fig. 1, and which was manufactured using a circular steel plate having a diameter of 2m, and the perforations at each stage in each radial arm were designed based on Julia group. Specifically, the complex function f is performed using Microsoft Visual C + + software with parameter settings of a-0.77, b-0.22, and k-150_c(z)＝z²And c, obtaining a perforation pattern of one radial arm, and forming 3 radial arms on the steel plate according to the perforation pattern to obtain the distribution plate shown in fig. 2A. The reactor used a conventional U-shaped heat exchange tube, which was a stainless steel tube with an internal diameter of 27 mm, extending from 10 cm below the liquid level to 10 cm above the distributor plate. Condensed water was supplied into the heat exchange tube at a flow rate of 1 m/sec.

Example 2

The slurry bed reactor of example 2 was designed in the same manner as in example 1 using the same process conditions except that a distribution plate including four radial arms (having an opening ratio of 21.26%) as shown in fig. 2B was used.

Example 3

The slurry bed reactor of example 3 was designed in the same manner as in example 1 using the same process conditions except that a distribution plate including five radial arms (having an opening ratio of 26.41%) as shown in fig. 2C was used.

Example 4

The slurry bed reactor of example 4 was designed in the same manner and under the same process conditions as in example 1, except that a distribution plate comprising six radial arms (having an opening ratio of 31.04%) as shown in fig. 2D was used.

Comparative example 1

The slurry bed reactor of comparative example 1 was designed in the same manner as in example 1, using the same process conditions, except that the distribution plate shown in fig. 3A was used, the multistage perforations in the distribution plate of fig. 3A were uniformly distributed throughout the distribution plate, and the total area of all the perforations was equal to the total area of the perforations in the distribution plate of fig. 2D of the present invention (i.e., the porosity was equal).

Comparative example 2

The slurry bed reactor of comparative example 2 was designed in the same manner as in example 1 except that the distributor plate shown in fig. 3B was used, the multistage perforations in the distributor plate of fig. 3B were distributed in the form of straight spiral arms, and the total area of all the perforations was equal to that of the perforations of the distributor plate shown in fig. 2A of the present invention (i.e., the porosity was equal).

Example 5

The slurry bed reactor of example 5 was designed in the same manner as in example 1 except that the heat exchange tubes shown in FIG. 5, which were formed in a DNA-like spiral structure and spirally ascended around the longitudinal axis of the reactor, were additionally used, and the two heat exchange tubes had an inner diameter of 27 mm, a diameter of 42 cm per spiral period in a cross section perpendicular to the longitudinal axis of the reactor, and an ascending diameter of 150 cm per spiral period. The heat exchange tubes are arranged in the slurry layer, and the total height of the heat exchange tubes is 15 meters. During the reaction, condensed water was fed into each heat exchange tube at a flow rate of 1 m/sec.

Example 6

The slurry bed reactor of example 6 was designed in the same manner as in example 1 except that three heat exchange tubes as shown in fig. 7, which were formed in a concentric spiral structure having a small lower portion and a large upper portion and spirally raised around the longitudinal axis of the reactor, were additionally used, each heat exchange tube had an inner diameter of 27 mm, a rise of 150 cm per one spiral period, and the diameter of the spiral period increased by 10% in a cross section perpendicular to the longitudinal axis of the reactor by one spiral period per one rise. The heat exchange tubes are arranged in the slurry layer, and the total height of the heat exchange tubes is 15 meters. The diameter of the uppermost circle (the largest size) of the outermost circle of heat exchange tubes on the top view of the reactor is 180 cm, the largest diameter of the middle circle of heat exchange tubes is 70% of the largest diameter of the outer circle of heat exchange tubes, and the largest diameter of the inner circle of heat exchange tubes is 70% of the largest diameter of the middle circle of heat exchange tubes. During the reaction, condensed water was fed into each heat exchange tube at a flow rate of 1 m/sec.

Example 7

The slurry bed reactor of example 7 was designed in the same manner as in example 5 except that a distribution plate including six radial arms as shown in fig. 2D was used.

Example 8

The slurry bed reactor of example 8 was designed in the same manner as in example 6 except that a distribution plate including six radial arms as shown in fig. 2D was used.

Example 9

The slurry bed reactor of example 9 was designed in the same manner as in example 5 except that a conventional spiral heat exchange tube having an inner diameter of 27 mm was used to spirally ascend around the longitudinal axis of the reactor and a diameter of 42 cm per spiral period in a cross section perpendicular to the longitudinal axis of the reactor, and the ascension of 150 cm per spiral period was carried out. The heat exchange tubes are arranged in the slurry layer, and the total height of the heat exchange tubes is 15 meters. During the reaction, condensed water was fed into each heat exchange tube at a flow rate of 1 m/sec.

Example 10

The slurry bed reactor of example 10 was designed in the same manner as in example 2 except that the distribution plate comprising four radial arms shown in fig. 4 was used, and the perforation pattern in each radial arm in fig. 4 was not set according to Julia set, but was designed according to a sine function (the opening ratio of the pattern shown in fig. 4 was the same as that of fig. 2B).

The applicant characterized the products of all the inventive and comparative examples described above and characterized and analyzed the composition of the product drawn off at the outlet of the reactor using a gas chromatograph model GC-14C, manufactured by shimadzu corporation. In addition, in order to monitor the temperature distribution in the reactor, a temperature sensor is arranged in the slurry bed layer in the reactor from the distribution plate at intervals of 0.5 meter in height adherence, the reading of each temperature sensor is read after the reaction is stable, and the average value T of all the temperature sensors is taken_{Are all made of}And then obtaining the value of T in the readings of the temperature sensors_{Are all made of}The mean Δ T of the absolute values of all differences was taken as the "mean temperature float absolute value" to rate the heat transfer efficiency within the system.

The results are summarized in table 1 below:

from the experimental results presented in the above table, it can be seen that the present invention, by making the pattern of the perforations in the distribution plate exclusively asymmetric compared to the most homogeneous pattern design concept generally adopted in the prior art, surprisingly allows a significant improvement in both the feed gas conversion and the selectivity of the high-carbon high-value product. The inventors surmise that such asymmetric perforation pattern design may have a certain particularly advantageous effect on mass transfer in a gas-liquid-solid three-phase slurry, promoting conversion and selectivity of the catalytic reaction. In addition, the inventors have also found that with two specially designed heat exchange tube configurations, more significant heat and mass transfer efficiencies are achieved, as shown in examples 5-8, resulting in further significant improvements in feed gas conversion and selectivity to high carbon high value products.

Claims

1. A slurry bed reactor comprising a housing, an inlet at the bottom of the housing, an outlet at the top of the housing, a distribution plate in the interior space surrounded by the housing, and a separator in the interior of the space above the distribution plate, characterized in that:

a plurality of primary perforations in the first group of perforations are distributed in a form of two to twelve spiral arms relative to the geometric center of the distribution plate, a connecting line of the geometric centers of the primary perforations included in each spiral arm forms a nonlinear spiral line extending from the geometric center of the distribution plate to the edge of the distribution plate, and the aperture of the primary perforations in the same spiral arm is 0.5-10 mm;

a plurality of secondary perforations in the second set of perforations are distributed in each spiral arm, one to six associated secondary perforations are arranged near each primary perforation, and the ratio of the aperture of each primary perforation to the aperture of each associated secondary perforation is 3:2 to 10: 1; the included angle between the connecting line of the centers of the secondary perforations and the center of the corresponding primary perforation and the tangential direction of the center of the primary perforation on the central connecting line is 10-170 degrees, and the distance between the center of the secondary perforation and the center of the primary perforation is 110-300 percent of the radius length of the primary perforation.

2. The slurry bed reactor of claim 1 wherein the distributor plate further comprises a third set of perforations comprising a plurality of tertiary perforations, the plurality of tertiary perforations in the third set of perforations being distributed in each spiral arm, one to six associated tertiary perforations being provided adjacent to each secondary perforation, the ratio of the pore size of each secondary perforation to the pore size of each associated tertiary perforation being from 3:2 to 10: 1; the included angle between the connecting line of the centers of the three-stage perforations and the center of the corresponding second-stage perforation and the tangent direction of the center of the second-stage perforation on the connecting line of the centers is 10-170 degrees, and the distance between the center of the third-stage perforation and the center of the second-stage perforation is 110-200 percent of the radius length of the second-stage perforation.

3. The slurry bed reactor of claim 2 wherein the distribution plate further comprises a fourth set of perforations comprising a plurality of fourth stage perforations, the plurality of fourth stage perforations in the fourth set of perforations being distributed in each spiral arm, one to six associated fourth stage perforations being provided adjacent to each third stage perforation, the ratio of the pore size of each third stage perforation to the pore size of each associated fourth stage perforation being from 3:2 to 10: 1; the included angle between the connecting line of the center of the four-level perforation and the center of the corresponding three-level perforation and the tangential direction of the center of the three-level perforation on the connecting line of the centers is 10-170 degrees, and the distance between the center of the four-level perforation and the center of the three-level perforation is 110-200 percent of the length of the radius of the two-level perforation.

4. The slurry bed reactor according to any one of claims 1 to 3 wherein the two to twelve spiral arms are in a centrosymmetric relationship with respect to the geometric center of the distributor plate; and/or

The primary perforations, secondary perforations, and optionally tertiary and quaternary perforations, have a shape selected from the group consisting of: circular, elliptical, oval, rhomboid, rounded rhomboid, square, rounded square, rectangular, rounded rectangle, irregular, and combinations thereof; and/or

And the aperture of the primary through holes in the same spiral arm is gradually increased and then gradually decreased along the direction from the geometric center of the distribution plate to the edge of the distribution plate.

5. The slurry bed reactor according to any one of claims 1-3, wherein the overall distribution pattern of all perforations in each spiral arm is a multi-level fractal non-uniform spiral pattern.

6. The slurry bed reactor of any one of claims 1-3, wherein the overall distribution pattern of all perforations in each spiral arm is a multi-level fractal non-uniform spiral pattern defined at least in part by Julia set fractal.

7. The slurry bed reactor of claim 6, wherein the Julia set is obtained from an iteration of a complex function of the formula:

f_c(z)＝z²+c

wherein the initial value of Z is Z₀Is 0, c is a plurality of a + bi, a is more than or equal to-1 and less than or equal to 1, b is more than or equal to 1 and more than or equal to 1, the iteration is carried out for k times, and k is more than or equal to 5 and less than or equal to 200.

8. The slurry bed reactor of claim 7,

-0.92≤a≤-0.23；

0.08≤b≤0.73；

20≤k≤190。

9. the slurry bed reactor of claim 7,

-0.85≤a≤-0.36；

0.12≤b≤0.68；

50≤k≤180。

10. the slurry bed reactor of claim 7,

-0.80≤a≤-0.51；

0.18≤b≤0.51；

80≤k≤170。

11. the slurry bed reactor of claim 7,

-0.79≤a≤-0.62；

0.20≤b≤0.36；

100≤k≤160。

12. the slurry bed reactor of claim 7,

a＝-0.77；

b＝0.22；

k＝150。

13. the slurry bed reactor according to any one of claims 1 to 3, further comprising a heat exchanger disposed in the interior space enclosed by the reactor housing, the heat exchanger comprising at least two heat exchange tubes disposed in a DNA-like double helix shape extending around the longitudinal axis of the reactor.

14. The slurry bed reactor according to any one of claims 1 to 3, further comprising a heat exchanger disposed in the inner space surrounded by the reactor shell, the heat exchanger comprising at least two heat exchange tubes disposed in the form of concentric spirals extending along the longitudinal axis of the reactor, and each spiral having a gradually increasing transverse dimension in a direction from bottom to top.