KR20160083298A - Gas dispensing device for dehydogenation reactor - Google Patents

Abstract

The present invention relates to a gas dispersing device for a dehydrogenation reactor which comprises at least one elongated gas dispersing pipes adjacent to each other and arranged repeatedly along a circumference in a single line. In the gas dispersing device, each gas dispersing pipe comprises an inlet hole through which a reaction gas in introduced and an outlet partition having a plurality of discharge holes through which the reaction gas is dispersed into a cyclic reaction zone, wherein the discharge holes are spaced apart from each other by a predetermined distance along the longitudinal direction on the outlet partition to form rows, each row has a plurality of discharge holes aligned along the transverse direction, the discharge holes positioned in one row have a different number or area from the discharge holes positioned in another row. The present invention also relates to a dehydrogenation reactor comprising the gas dispersing device. According to the present invention, it is possible to control the flux of the reaction gas dispersed to the cyclic reaction zone depending on user′s purpose, and thus to minimize a deviation in flow rate between the upper portion and lower portion of the reactor.

Description

[0001] GAS DISPENSING DEVICE FOR DEHYDOGENATION REACTOR [0002]

The present invention relates to a gas dispersing apparatus for a dehydrogenation reactor, and more particularly, to a gas dispersing apparatus for a dehydrogenation reactor capable of uniformly dispersing a gas by controlling a flow rate of a gaseous reactant diffused into a catalyst bed in a reactor .

The dehydrogenation reaction, such as dehydrogenation of propane with propylene and isobutane with isobutene, produces olefins which are more reactive than alkane feedstocks and which are easier to form coke, at relatively high temperatures used for dehydrogenation. The dehydrogenation reactor is a very large, long columnar vertical structure with a diameter of about 5 to 30 feet and a length of 10 to 100 feet or more. The general structure of such a reactor can be injected into the inlet located at the bottom center of the vertical reactor, where the gas flows through the annular zone and passes radially outward through a porous catalyst bed or other suitable dehydrogenation catalyst Passes upwardly through the outer annular zone to be discharged at the top of the outer periphery of the reactor. These reactors are often referred to as "radial" reactors because the reactant gas flow through the catalyst bed is radial.

Generally, the radial flow reaction zone consists of cylindrical zones having various nominal cross-sectional areas, which are arranged vertically and coaxially to form reaction zones. Typically, the radial flow reaction zone includes a cylindrical reaction vessel having a cylindrical outer catalyst containing screen and a cylindrical inner catalyst containing screen coaxially disposed with the reaction vessel. The inner screen has a nominal inner cross-sectional area smaller than the outer screen and has a nominal inner cross-sectional area smaller than the reaction vessel. The reactant stream is introduced into the annular space present between the inner wall of the reaction vessel and the outer surface of the outer screen. The reactant stream flows radially through the annular space existing between the outer and inner screens through the outer screen and then through the inner screen. The collected stream into the cylindrical space inside the inner screen is withdrawn from the reaction vessel. The reaction vessel, the outer screen and the inner screen may be cylindrical, but they may also take any suitable form, for example, triangular, square, elliptical and diamond shapes, depending on various design, manufacturing and technical considerations. For example, the outer screen is not a continuous cylindrical screen, but instead is usually a separate elliptical tubular screen gas distributor, also referred to as a scallop, which is disposed along the circumference of the inner wall of the reaction vessel. The inner screen is usually a perforated center pipe covered with a screen along the outer circumference. Scallops are preferred for many radial flow reactors because of their low cost and simplicity of design compared to other continuous screen design configurations. The face of the screen is configured to support the distribution of pressure across the reactor surface in order to maintain the catalyst bed in place and facilitate the radial flow. The screen may be a mesh or punched plate of wire or other material.

Fig. 1 discloses a design of a gas distribution tube for use in a radial flow reactor according to the prior art. According to the disclosure of the patent document, the gas distribution tube structure 1 is a structure in which the fluid that has entered the inlet is dispersed into several regions via outlet holes 2. [ The size and number of the discharge holes (2) are the same throughout the gas distribution tube. Therefore, in the case of the gas separation module using the gas distribution module, a flow rate variation occurs in each gas distribution pipe section because a larger amount of flow is dispersed toward the inlet port. The flow rate increases at the discharge hole near the inlet and the flow rate at the inlet and the far outlet decreases so that the flow velocity difference between the upper and lower portions of the reactor becomes worse and there is a restriction on the smooth utilization of the catalyst layer.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the problems of the prior art described above and to provide a method and apparatus for injecting a fluid flowing into a reactor uniformly, And it is an object of the present invention to provide a gas distributing apparatus capable of extending its service life.

Another object of the present invention is to provide a dehydrogenation reactor capable of arbitrarily controlling a flow rate deviation of a gaseous reactant injected into a cyclic reaction zone according to the intended use.

According to one aspect of the present invention for achieving the above object,

The gas distribution device for a dehydrogenation reactor in which one or more long gas distribution tubes are repeatedly arranged in a circular shape along a circumference with a single row adjacent to each other is characterized in that each of the gas distribution tubes has an inlet hole as a hole through which the reaction gas flows, And a plurality of discharge holes having a plurality of discharge holes which are holes dispersed in the annular reaction region, wherein the discharge holes are formed in rows spaced apart at predetermined intervals in the longitudinal direction on the discharge partition wall, Wherein a plurality of discharge holes arranged in a row are formed in the column and discharge holes located in different rows are different in number or area or are different in number and area from each other .

According to another aspect of the present invention for achieving the above object,

A catalyst inlet, a reactor inlet for supplying a fluid reactant to the inside of the reactor, a reactor radially surrounding the center of the reactor, and a concentrator 1. A dehydrogenation reactor comprising a cyclic reaction zone defined by an inner screen and an outer screen of a catalyst bed on a reactor bed and a reactor outlet for withdrawing a reactant stream from within the reactor,

Characterized in that the gas dispersing apparatus of the present invention is installed adjacent to at least one of the inner screen and the outer screen.

According to the gas dispersion apparatus for a dehydrogenation reactor according to the present invention, it is possible to control the amount of the fluid of the reaction gas dispersed in the annular reaction zone, thereby minimizing the deviation in the flow velocity between the upper part and the lower part of the reactor. Therefore, by minimizing the flow velocity deviation in the upper and lower layers, the inner layer and the outer layer of the catalyst bed, the catalyst bed can be used evenly and the reactor performance can be maximized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a gas distribution tube design shape used in a radial flow reactor according to the prior art; FIG.
2 is a schematic cross-sectional view of a dehydrogenation reactor according to an embodiment of the present invention.
3 is a schematic plan view of a gas distribution apparatus according to an embodiment of the present invention.
4 is a schematic perspective view of a gas distribution tube according to an embodiment of the present invention.
5 is a graph showing a flow rate distribution of a gaseous reactant according to a longitudinal position of the gas dispersion pipe according to the prior art and a graph showing a flow rate distribution of a gaseous reactant according to a longitudinal position of the gas dispersion pipe according to Fig.
6 is a schematic perspective view of a gas distribution tube according to another embodiment of the present invention.
7 is a schematic perspective view of a gas distribution tube according to another embodiment of the present invention.
8 is a graph showing the flow rate of the gaseous reactant according to the longitudinal position of the gas distribution tube according to Figs. 6 and 7. Fig.
9 (a) is a schematic perspective view showing a single discharge hole according to an embodiment of the present invention, and FIG. 9 (b) is a sectional view of a discharge hole Fig.

The present invention will now be described in more detail with reference to the accompanying drawings. Although the terms used in the present invention have been selected as general terms that are widely used at present, there are some terms selected arbitrarily by the applicant in a specific case. In this case, the meaning described or used in the detailed description part of the invention The meaning must be grasped. Like reference numerals refer to like elements throughout the specification.

Although the drawings illustrate specific shapes of the dehydrogenation reactor of the present invention, such a dehydrogenation reactor may have various shapes suitable for the specific environment in which it is performed in a particular application, Moreover, the numbers in the figures represent a simplified schematic diagram of the dehydrogenation reactor of the present invention and only the major components are shown. Other pumps, moving pipes, valves, hatches, access outlets and other similar components have been omitted.

 The use of these components to modify the described dehydrogenation reactor is well known to those skilled in the art and does not depart from the scope and spirit of the appended claims.

As used herein, the term "fluid" means a gas, liquid, or gas or liquid containing a dispersed solid or a mixture thereof. The fluid may be in the form of a gas containing dispersed droplets.

As used herein, the term "reaction zone" means the space in the dehydrogenation reactor where the reactants are in contact with the catalyst on the catalyst bed.

Here, the direction of the flow of solids through the device in the downward or gravitational direction, that is to say through the cross-flow gas, is oriented, so the use of the terms 'downward' and 'upward' is relative to the direction of the gravitational direction.

The term "screen " as used herein has a broad meaning, including means suitable for limiting the catalyst to the catalyst bed, while allowing flow of the reactant stream across the catalyst bed. Because catalyst particles falling through the annular catalyst bed in the present invention are somewhat weak, it is desirable to design the internal and external catalyst holding screens to reduce catalyst wear. Alternatively, the screens may comprise punch plates, perforated plates or perforated pipes. The size of the pores should be such that the flow of reactants through the screen is facilitated, while the passage of the catalyst particles is inhibited. The holes of the perforated plate may be in the form of a circle, a square, a rectangle, a triangle, a narrow horizontal or vertical slot, or the like. The screens used in the present invention are not limited to cylindrical screens. Furthermore, the screens comprise a group of planar plates interconnected to form a catalyst particle retaining structure, such as a cylinder.

2 is a schematic cross-sectional view of a dehydrogenation reactor 100 according to an embodiment of the present invention.

Referring to FIG. 2, the dehydrogenation reactor 100 according to an embodiment of the present invention includes a housing 20 forming the inside of a dehydrogenation reactor, a reactor inlet 21 for supplying a fluid reactant into the reactor, An annular reaction zone (25) enclosing the catalyst bed of the catalyst particles (11) and containing a concentric catalyst bed and defined by an inner screen (23) and an outer screen (24) And a reactor outlet 26 for recovering the reactant stream The reactor inlet 21 is formed at the lower end of the reactor and the reactor outlet 26 is formed in the same reactor side as the reactor inlet 21 do. The dehydrogenation reactor 100 is configured to contact the reactant stream with the radial stream from the catalyst particles that are transferable to the annular catalyst bed by the gravity stream.

Referring to FIG. 2, the dehydrogenation reactor 100 is constituted by an outer cylindrical housing 20, and the annular reaction zone 25 including the catalyst bed accommodated therein is spaced radially from one another. The upper portion of the reaction zone of the housing 20 includes a catalyst inlet 10 connected in an open state to a space around the catalyst bed. This catalyst inlet 10 feeds the catalyst to the catalyst bed in the annular reaction zone 25. The catalyst particles 11 pass through at least one inlet passage 12 which opens into the upper portion of the housing 20 from the catalyst inlet 10 at the upper end of the housing 20 to form an annular reaction in the upper portion of the housing 20 Is introduced into the catalyst bed of the zone 25 and the catalyst is exhausted through the plurality of catalyst outlet pipes 27 located in the lower part of the catalyst bed in the annular reaction zone 25. [

The inner screen 23 and the outer screen 24 formed on the inside and the outside of the catalyst bed are large enough to allow the fluid flow stream to pass without flow resistance or a large pressure drop so that the accommodated catalyst particles 11 can not pass, And a screen or porous body having a mesh size small enough to be placed on the screen.

A reactor feed comprising a hydrocarbon to be treated at a suitable temperature and pressure in the dehydrogenation reactor of the present invention, ie, a reactant gas, flows through the reactor inlet 21 and enters the annular reaction zone containing the catalyst bed of the dehydrogenation reactor 100 (25). The reaction gas passes through the catalyst bed and is finally discharged to the reactant outlet 26 formed on the upper side of the reactor. The catalyst particles 11 flow under the annular reaction zone 25 and the annular reaction zone 25 is formed by the inner screen 23 and the outer screen 24 forming a particle holding volume for holding the catalyst bed. The reaction gas flows through the screen and the catalyst bed to react with the catalyst to produce product fluids, and also typically gases. The reactor uses a screen through which the gas flows to keep the catalyst inside.

The dehydrogenation reactor 100 according to the present invention is characterized in that it includes a gas dispersing device 300 for diffusing a reaction gas into the annular reaction zone 25 on the outside of the external screen 24. The gas distributor 300 is installed between the housing 20 and the annular reaction zone 25 and disperses the reaction gas introduced into the reactor inlet 21 into the catalyst bed. In one embodiment, the gas distributor 300 may be a vertical cylinder comprising orifices that diffuse the gas into the interior space. The gas dispersing apparatus 300 of the present invention can be installed in a dispersion zone between the outer wall of the reactor and the outer screen.

3 is a schematic plan view of a gas distribution apparatus according to an embodiment of the present invention. Referring to FIG. 3, the gas distributing apparatus 300 of the present invention is a gas distributing apparatus in which one or more long gas distributing pipes 30 are arranged in a circular shape along a circumference with a single row adjacent to each other. (33) and both sides (34). The gas distribution tubes 30 are circularly arranged in a single row around the catalyst bed, and the front surface of each gas distribution tube 30 is divided into an outlet partition wall 33 having a plurality of discharge holes for dispersing and distributing gas .

4 is a schematic perspective view of a gas distribution tube according to an embodiment of the present invention. 4, the gas distribution pipe 30 includes an outlet hole 31, which is a hole through which the reaction gas flows, and an outlet hole 33, which has a plurality of outlet holes 32, through which the reaction gas is discharged. .

As shown in FIG. 4, the discharge holes 32 are spaced apart from each other by a predetermined distance in the longitudinal direction. The discharge holes 32 are formed in a row in a transverse direction, that is, in a direction perpendicular to the longitudinal direction One or more discharge holes 32 spaced apart from one another are arranged. The gas distribution pipe 30 may be formed in a conduit shape. In FIG. 4, the gas distribution pipe 30 having a rectangular cross-section is shown. However, the cross-sectional shape of the gas dispersion pipe 30 may be a curved -rectangle < / RTI > or hemispherical gas distribution tubes 30 may also be considered.

The dehydrogenation reactor 100 of the present invention may be a structure in which the reaction flow passes from the reactor top via the gas distributor 300 through the catalyst bed and into the bottom of the final reactor, It may be a structure that passes through the dispersing device 300, passes through the catalyst bed, and exits to the upper portion of the final reactor.

4, according to the present invention, the discharge holes 32 of the gas distributing pipe 30 are arranged in such a manner that the area of the discharge holes 32 And the number of the discharge holes 32 gradually decreases. Thus, by varying the size and / or number of the discharge holes 32, it is possible to reduce the flow rate fluctuation of the fluid ejected from the discharge holes 32 by uniformly controlling the amount of fluid of the discharged gaseous reactant. 4, the number of the discharge holes 32 nearest to the inlet hole 31 is five, and the number of the discharge holes 32 farthest from the inlet hole 31 is two And the number and area of the discharge holes 32 can be freely adjusted by a person skilled in the art to which the present invention belongs.

FIG. 5 is a graph showing the distribution of the flow rate of the gaseous reactant according to the longitudinal position of the gas dispersion pipe according to the prior art, and a graph showing the distribution of the flow rate of the gaseous reactant according to the longitudinal position of the gas dispersion pipe according to FIG. to be. 5, in the case of a gas distribution tube having a constant size and number of discharge holes 32, the flow rate decreases from the upper portion A to the lower portion B, so that the flow rate of the gaseous reactant injected through the discharge hole In the case of the gas distribution pipe 30 according to FIG. 4, the flow rate of the gas reactant injected through the discharge holes 32 is uniformly distributed even when the gas reactant proceeds to the lower portion B, .

According to another embodiment of the present invention, it is also possible to control the flow rate of the gaseous reactant injected through the discharge holes 32 according to the user's request. 6 is a schematic perspective view of a gas distribution tube according to another embodiment of the present invention. Referring to FIG. 6, it can be seen that the area of the discharge holes 32 gradually decreases and the number of the discharge holes 32 gradually increases toward the lower portion of the gas distribution tube 30.

7 is a schematic perspective view of a gas distribution tube according to another embodiment of the present invention. Referring to FIG. 7, it can be seen that the area of the discharge holes 32 gradually increases and the number of the discharge holes 32 gradually decreases toward the lower portion of the gas distribution tube 30. In the case of FIG. 7, unlike FIG. 4, the degree of increase of the area of the discharge holes 32 may be adjusted to a larger width so that the flow rate of the gaseous reactant is moderately increased.

FIG. 8 is a graph showing the distribution of the flow rate of the gaseous reactant according to the longitudinal position of the gas distribution tube according to FIGS. 6 and 7. FIG. 6, the flow rate of the gas dispersion pipe according to FIG. 6 decreases sharply from the upper portion A to the lower portion B, and the gas dispersion pipe according to FIG. It can be seen that the flow rate of the gaseous reactant injected through the discharge holes 32 gradually increases.

9 (a) is a schematic perspective view showing a single discharge hole according to an embodiment of the present invention, and Fig. 9 (b) is a sectional view of a discharge hole Fig. 9 (b), a discharge hole cover 35 is formed on an upper portion of the discharge hole 32, which is a direction in which the fluid enters, so that the fluid discharged through the discharge holes 32 by the discharge hole cover 35 The direction and the flow rate of the fluid can be controlled to be constant.

In the present invention, the diameter of the discharge holes 32 is about 0.3 to 6 cm, and the extent to which the area of the discharge holes 32 increases or decreases is 3 to 200% as compared with the discharge holes 32 arranged in the adjacent rows. Of the total amount of water. The ratio is freely adjustable by an ordinary technician according to the user's intention. As described above, the gas distribution pipe 30 according to the present invention is capable of controlling the number of the discharge holes 32 by adjusting the area of the discharge holes 32 or adjusting the number of the discharge holes 32, It is possible to arbitrarily adjust the flow rate deviation according to the purpose of use. For example, when it is desirable that the flow rate distribution of the gaseous reactant is constant in each reaction zone, the area and / or number of the discharge holes 32 near the inlet holes 31 are reduced, The flow rate of the gaseous reactant that has been biased adjacent to the inlet hole 31 can be regulated.

The shape of the discharge holes 32 may be at least one selected from the group consisting of a circle, a square, a triangle, a star, a cross, and a rhombus, but is not limited thereto. In addition, the shape in which the discharge holes 32 are arranged in the transverse direction in the gas distribution tube 30 can be variously implemented in a straight line or a curved line, and can be arranged, for example, in a straight line or in a wave form But are not necessarily limited thereto.

2, in the dehydrogenation reactor 100 according to the present invention, in order to efficiently control the temperature when the catalyst temperature rises, a ring-shaped disk-shaped heat treatment unit 13 may be installed at an upper portion of the reactor have. In the heat treatment unit 13, the reactant is heated or cooled to a suitable temperature by contact with a reducing gas introduced through the heat treatment gas inlet 14. The heat transfer medium flowing in the heat treatment space supplies heat to the process gas Or recover heat from the process gas. In general, the heating and cooling means of the present invention comprise a heat treatment section 13 disposed with respect to at least one catalyst bed such that the gaseous process stream radially entering or exiting the at least one catalyst bed, if necessary, Can be cooled. In one embodiment, the heat treatment section 13 may be disposed in the reactor core region inside the annular portion of the innermost catalyst bed on a single catalyst bed or a series of radially spaced concentric annular catalyst beds.

Hereinafter, the dehydrogenation reaction in the dehydrogenation reactor of the present invention will be described. Referring to FIG. 2, the gaseous reactant introduced through the reactor inlet 21 is injected through the gas distributor 300 and radially passed through the annular reaction zone 25 to dehydrogenate the hydrocarbon to the desired end product. The reactant stream radially emerging from the annular reaction zone 25 through the inner screen 23 is transferred to the annular region, which is the collection zone or the reheating or cooling zone or both. The reacted reactant stream leaves the dehydrogenation reactor 100 via the reactor outlet 26 and is sent for further processing.

While the invention has been described in connection with various specific embodiments, it is to be understood that various modifications thereof will become apparent to those of ordinary skill in the art upon reading the specification. Accordingly, the invention as described herein is intended to embrace such modifications as fall within the scope of the appended claims.

100: dehydrogenation reactor 10: catalyst inlet
11: reaction catalyst 12:
13: heat treatment part 14: heat treatment gas inlet
20: Housing 21: Reactant inlet
22: purge gas inlet 23: inner screen
24: external screen 25: catalyst bed
26: reactor outlet 27: catalyst outlet pipe
300: gas distributor 30: gas distributor tube
31: inlet hole 32: outlet hole
33: outlet bulkhead 34: side
35: discharge hole cover

Claims (10)

The gas distribution device for a dehydrogenation reactor in which one or more long gas distribution tubes are repeatedly arranged in a circular shape along a circumference with a single row adjacent to each other is characterized in that each of the gas distribution tubes has an inlet hole as a hole through which the reaction gas flows, And a plurality of discharge holes having a plurality of discharge holes which are holes dispersed in the annular reaction region, wherein the discharge holes are formed in rows spaced apart at predetermined intervals in the longitudinal direction on the discharge partition wall, Wherein a plurality of discharge holes arranged in a row are formed in the column and discharge holes located in different rows are different in number or area or are different in number and area.
2. The method of claim 1, wherein the discharge holes increase in area toward the bottom of the gas distribution tube and the number of the discharge holes decreases to distribute the flow rate of the gaseous reactant dispersed to the annular reaction region through the discharge holes Wherein the gas-liquid separator is a gas-liquid separator.
2. The method of claim 1, wherein the discharge holes are reduced in area toward the lower portion of the gas distribution pipe, and the number of the discharge holes is increased to distribute the flow rate of the gas reactant dispersed to the annular reaction region through the discharge holes, Wherein the gas-liquid separator is a gas-liquid separator.
The gas dispersion apparatus for a dehydrogenation reactor according to claim 1, wherein the shape of the discharge holes is at least one selected from the group consisting of a circle, a square, a triangle, a star, a cross, and a rhombus.
The gas dispersion apparatus for a dehydrogenation reactor according to claim 1, wherein the shape in which the discharge holes are arranged in a transverse direction in the gas distribution tube is a linear shape or a wave form.
The gas dispersion apparatus for a dehydrogenation reactor according to claim 1, wherein the cross-sectional shape of the gas distribution pipe is a square, a rectangle, a curved-rectangle or a hemispherical shape.
The gas dispersion apparatus for a dehydrogenation reactor according to claim 1, wherein a discharge hole cover is formed on the discharge holes to adjust a direction and a flow rate of the fluid discharged through the discharge holes.
A catalyst inlet, a reactor inlet for supplying a fluid reactant to the inside of the reactor, a reactor radially surrounding the center of the reactor, and a concentrator 1. A dehydrogenation reactor comprising a cyclic reaction zone defined by an inner screen and an outer screen of a catalyst bed on a reactor bed and a reactor outlet for withdrawing a reactant stream from within the reactor,
Wherein a gas dispersing apparatus according to any one of claims 1 to 7 is provided adjacent to at least one of the inner screen and the outer screen.
The dehydrogenation reactor according to claim 8, wherein the dehydrogenation reactor is a structure in which the flow of the gaseous reactant passes through the gas dispersion unit at the upper end of the reactor, through the catalyst bed, and finally to the lower portion of the reactor.
The dehydrogenation reactor according to claim 8, wherein the dehydrogenation reactor is a structure in which the flow of the gaseous reactant passes through the gas dispersion unit at the bottom of the reactor, through the catalyst bed, and finally to the top of the reactor.

Images