CN109382070B

CN109382070B - Alkylation multistage reactor and alkylation reaction method

Info

Publication number: CN109382070B
Application number: CN201710671848.0A
Authority: CN
Inventors: 袁忠勋
Original assignee: Sinopec Engineering Inc; Sinopec Engineering Group Co Ltd
Current assignee: Sinopec Engineering Inc; Sinopec Engineering Group Co Ltd
Priority date: 2017-08-08
Filing date: 2017-08-08
Publication date: 2020-08-07
Anticipated expiration: 2037-08-08
Also published as: CN109382070A

Abstract

The present disclosure relates to an alkylation multistage reactor and an alkylation reaction method. The reactor comprises a mixing-reaction element with a specific structure, wherein a liquid catalyst and a reaction feed in the mixing-reaction element enter a reaction zone through a pore channel in a 'hedging injection' mode to perform mixing reaction, so that the reaction feed and the liquid catalyst can be fully mixed and contacted in the reaction zone, the mixing and reaction efficiency is high, the selectivity and the product quality are improved, multi-stage reaction can be realized, the alkane-alkene ratio is optimized, the reaction efficiency is improved, and the investment and the occupied area of the reactor are reduced; through setting up the interstage communicating pipe, make the mixture of liquid catalyst and last order reaction product get into the second liquid channel that takes place alkylation reaction through the reaction feed zone of next stage module, interstage reaction feeding all gets into the second liquid channel through first liquid channel, and the material flow direction matches with the flow proportion of the interior material of reactor, more is favorable to the improvement of alkylation reaction efficiency.

Description

Alkylation multistage reactor and alkylation reaction method

Technical Field

The disclosure relates to the field of petrochemical industry, in particular to an alkylation multistage reactor and an alkylation reaction method.

Background

The reaction in the alkylation reactor of petrochemical industry is carried out under the action of catalyst, the catalyst is divided into two forms of solid and liquid, and the liquid catalyst is usually acidic ionic liquid. It is known from the research of reaction mechanism that for the alkylation reaction process using liquid catalyst, the reaction is mainly completed at the interface of two phases of liquid phase catalyst and hydrocarbon reaction raw material, and the renewal rate of the interface and the ratio of alkane to alkene (alkane-alkene ratio) near the interface are the key factors affecting the selectivity of the main reaction. To achieve higher selectivity for the alkylated product, the alkylation reaction requires strong liquid-liquid mixing and a higher ratio of reacted alkane to alkene.

The existing liquid alkylation technology basically adopts a reactor similar to a static mixer and adopts a mode of multi-section feeding of a plurality of reactors to improve the alkane-olefin ratio in the reactor and strengthen liquid-liquid mixed mass transfer so as to achieve the purposes of improving the selectivity of alkylate oil and improving the product quality. However, the reactor of the type has poor mixing effect, needs a plurality of independent horizontal reactors, and has high investment and large floor area.

Disclosure of Invention

The present disclosure provides an alkylation multistage reactor and an alkylation reaction method, which have good liquid-liquid mixing mass transfer effect, can effectively promote alkylation reaction and inhibit side reaction, and can greatly improve the selectivity and product quality of alkylate oil compared with other mixing forms.

To achieve the above objects, a first aspect of the present disclosure provides an alkylation multistage reactor comprising a housing, a mix-reaction module, an interstage partition, a first stage reaction feed inlet, a liquid catalyst inlet, an interstage reaction feed inlet, and a discharge outlet; the first-stage reaction feeding inlet is positioned at the top of the shell, the discharging port is positioned at the bottom of the shell, and a plurality of stages of mixing-reaction modules are arranged in the shell at intervals from top to bottom; the mixing-reaction module comprises an upper partition plate, a lower partition plate and a plurality of mixing-reaction elements which are arranged in parallel at intervals, the end edges of the upper partition plate and the lower partition plate are respectively and fixedly connected with the inner wall of the shell in a sealing way so as to form a reaction feeding area between the upper partition plate and the lower partition plate, each mixing-reaction element vertically penetrates through the reaction feeding area and is respectively and fixedly connected with the upper partition plate and the lower partition plate in a sealing way, and the liquid catalyst inlet is arranged on the shell between the upper partition plate and the lower partition plate of the first-stage mixing-reaction module positioned at the top end of the shell; said interstage diaphragms being disposed horizontally between said mixing-reaction modules of adjacent stages, the end edges of said interstage diaphragms being in sealing fixed connection with the inner wall of said shell such that said interstage diaphragms form reaction feed distribution chambers with the adjacent upper and inner walls of said shell, said interstage diaphragms forming reaction product and liquid catalyst collection chambers with the adjacent lower and inner walls of said shell, said interstage diaphragms having downwardly extending interstage communication tubes to communicate the reaction product and liquid catalyst collection chambers with the reaction feed regions of said mixing-reaction modules of adjacent stages; an interstage reaction feed inlet is arranged on the shell corresponding to each reaction feed distribution chamber; each of the mixing-reaction elements comprises a first tubular member and a second tubular member arranged axially; the inner part of the first tubular part is formed into a first liquid channel, and the second tubular part is sleeved outside the first tubular part to form a second liquid channel between the tube walls of the first tubular part and the second tubular part; the bottom end of the first tubular part is closed, the pipe wall of the first tubular part is provided with a plurality of first holes, and the top end of the first tubular part is provided with a first opening; the pipe wall of the second tubular part is provided with a plurality of second open holes, the bottom end of the second tubular part is provided with a second opening, and the top end of the second tubular part is in sealing connection with the top end of the first tubular part; the space above the upper baffle plate is in fluid communication with the interior space of the mixing-reaction element only through the first opening, the reaction feed zone is in fluid communication with the second liquid passage only through the second opening, and the space below the lower baffle plate is in fluid communication with the interior space of the mixing-reaction element only through the second opening.

Optionally, the top end opening of the interstage communication tube is located in the center of the interstage diaphragm.

Optionally, the number of stages of the mixing-reaction module is 2-12 stages.

Optionally, each of the mixing-reaction modules comprises a plurality of mixing-reaction elements distributed uniformly.

Optionally, the first tubular member is a round tube or a conical tube with an open upper end.

Optionally, the second tubular member is a circular tube or a conical tube with an open lower end.

Optionally, the diameter of the first opening is 1-10 mm, and the sum of the opening areas of all the first openings in each mixing-reaction element accounts for 1% -50% of the side wall area of the first tubular member.

Optionally, the diameter of the second openings is 1-10 mm, and the sum of the opening areas of all the second openings in each mixing-reaction element accounts for 1% -60% of the side wall area of the second tubular member.

In a second aspect of the present disclosure, there is provided a process for carrying out an alkylation reaction using the alkylation multistage reactor provided in the first aspect of the present disclosure, the process comprising the steps of: passing a first stage reaction feed from said first stage reaction feed inlet into said alkylation multistage reactor, then through a first opening in said first tubular member into said first liquid passage of a first stage mixing-reaction module, and then through said first opening into said second liquid passage; allowing liquid catalyst to enter the reaction feed region of the first-stage mixing-reaction module from the liquid catalyst inlet, allowing the liquid catalyst in the reaction feed region to enter the second liquid channel through the second opening, mixing with the first-stage reaction feed entering the second liquid channel through the first opening in a counter-jet manner, and performing alkylation reaction, wherein the obtained first-stage reaction product and liquid catalyst mixture flows out of the second opening, enters a reaction product and liquid catalyst collecting chamber, and then enters the reaction feed region of the second-stage mixing-reaction module through the interstage communication tube; passing a second stage reaction feed from said interstage reaction feed inlet into a reaction feed distribution chamber, then through a first opening of said first tubular member into said first liquid passage of a second stage mixing-reaction module, and then through said first opening into said second liquid passage; and the mixture of the first-stage reaction product and the liquid catalyst in the reaction feeding area enters the second liquid channel through the second opening, is mixed with the second-stage reaction feed entering the second liquid channel through the first opening in a counter-jet mode and is subjected to alkylation reaction, and the obtained mixture of the second-stage reaction product and the liquid catalyst flows out of the second opening, enters the reaction feeding area of the mixing-reaction module of the third stage through the interstage communicating pipe, or leaves the alkylation multistage reactor through the discharge hole.

Optionally, the liquid catalyst is an acidic ionic liquid catalyst.

Alternatively, the reaction feed is a mixture of olefins from C2 to C6 and isoparaffins from C2 to C6.

Through the technical scheme, the alkylation multistage reactor disclosed by the invention comprises a mixing-reaction element with a specific structure, wherein a liquid catalyst and a reaction feed in the mixing-reaction element enter a reaction zone in a second liquid channel in a counter-jet mode through a first opening and a second opening which are oppositely arranged to perform mixing reaction, so that the reaction feed and the liquid catalyst can be fully mixed and contacted in the reaction zone, the mixing and reaction efficiency is high, and the selectivity and the product quality are improved; the alkylation multistage reactor is internally provided with a plurality of mixing-reaction modules containing mixing-reaction elements to form a multistage reactor with graded feeding, and the alkylation multistage reactor and the method for carrying out alkylation reaction by using the alkylation multistage reactor can realize multistage reaction in one reactor, optimize the alkane-alkene ratio, improve the reaction efficiency, and reduce the investment and the occupied area of the reactor; meanwhile, in the alkylation multistage reactor disclosed by the invention, by arranging the interstage communicating pipe, a mixture of the liquid catalyst and the reaction product flowing out of the previous-stage module enters the second liquid channel for alkylation reaction through the reaction feeding area between the upper partition plate and the lower partition plate of the next-stage module, interstage reaction feeding enters the second liquid channel through the first liquid channel of the mixing-reaction element, the flow direction of the material is matched with the flow proportion of the material in the reactor, and the improvement of the alkylation reaction efficiency is better facilitated.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a schematic diagram of one embodiment of an alkylation multistage reactor provided by the present disclosure.

FIG. 2 is a schematic block diagram of a first stage hybrid-reaction module of one embodiment of an alkylation multistage reactor provided by the present disclosure.

FIG. 3 is a schematic top view of a first stage mixing-reaction module of one embodiment of an alkylation multistage reactor provided by the present disclosure (i.e., the AA cross-sectional view of FIG. 2).

FIG. 4 is a schematic diagram of a second stage to last stage hybrid-reaction module configuration of one embodiment of an alkylation multistage reactor provided by the present disclosure.

Fig. 5 is a schematic top view of a second stage to last stage hybrid-reaction module of one embodiment of an alkylation multistage reactor provided by the present disclosure (i.e., the BB cross-sectional view of fig. 4).

FIG. 6 is a schematic diagram of a hybrid-reactive element configuration of one embodiment of an alkylation multistage reactor provided by the present disclosure.

FIG. 7 is a schematic diagram of a hybrid-reactive element configuration of another embodiment of an alkylation multistage reactor provided by the present disclosure.

FIG. 8 is a schematic flow diagram of liquid flow within a mixing-reaction element of one embodiment of an alkylation multistage reactor provided by the present disclosure.

FIG. 9 is a schematic in-reactor liquid flow diagram for one embodiment of an alkylation multistage reactor provided by the present disclosure.

Description of the reference numerals

1 casing 2 Upper end socket

3 lower end socket 4 mixing-reaction module

6 reaction product and liquid catalyst collecting chamber

7 reaction feed distribution chamber 8 interstage baffle

9 interstage communicating tube 10 first stage reaction feed inlet

11 liquid catalyst inlet 12 interstage reaction feed inlet

13 discharge port 14 mixing-reaction element

15 upper partition board 16 lower partition board

17 first tubular member 18 second tubular member

19 second liquid passage 20 first opening

21 second opening 22 reaction feed zone

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, unless otherwise stated, the use of directional words such as "upper" and "lower" generally refers to "upper" and "lower" of the device in normal use, and specifically refer to the directions of the drawings of fig. 1-2, 6-9. "inner and outer" refer to the outline of the device.

As shown in fig. 1, a first aspect of the present disclosure provides an alkylation multistage reactor comprising a housing 1, a mixing-reaction module 4, an interstage partition 8, a first stage reaction feed inlet 10, a liquid catalyst inlet 11, an interstage reaction feed inlet 12, and a discharge outlet 13; the first-stage reaction feeding inlet 10 is positioned at the top of the shell 1, the discharging outlet 13 is positioned at the bottom of the shell 1, and a plurality of stages of mixing-reaction modules 4 are arranged in the shell 1 at intervals from top to bottom; the mixing-reaction module 4 comprises an upper partition 15, a lower partition 16 and a plurality of mixing-reaction elements 14 which are arranged in parallel and spaced apart, the end edges of the upper partition 15 and the lower partition 16 are respectively and fixedly connected with the inner wall of the shell 1 in a sealing manner to form a reaction feed area 22 between the upper partition 15 and the lower partition 16, each mixing-reaction element 14 vertically penetrates through the reaction feed area 22 and is respectively and fixedly connected with the upper partition 15 and the lower partition 16 in a sealing manner, and the liquid catalyst inlet 11 is arranged on the shell 1 between the upper partition 15 and the lower partition 16 of the first-stage mixing-reaction module 4 at the top end of the shell 1; the interstage diaphragms 8 are horizontally arranged between the mixing-reaction modules 4 of the adjacent two stages, the end edges of the interstage diaphragms 8 are fixedly connected with the inner wall of the shell 1 in a sealing way, so that the interstage diaphragms 8, the adjacent upper diaphragms 15 and the inner wall of the shell 1 form reaction feed distribution chambers 7, the interstage diaphragms 8, the adjacent lower diaphragms 16 and the inner wall of the shell 1 form reaction product and liquid catalyst collecting chambers 6, and the interstage diaphragms 8 are provided with interstage communicating pipes 9 extending downwards so as to communicate the reaction product and liquid catalyst collecting chambers 6 of the mixing-reaction modules 4 of the adjacent two stages with a reaction feed area 22; an interstage reaction feed inlet 12 is arranged on the shell 1 corresponding to each reaction feed distribution chamber 7; each of said mixing-reaction elements 14 comprises a first tubular member 17 and a second tubular member 18, axially arranged; the first tubular member 17 is internally formed into a first liquid passage, and the second tubular member 18 is sleeved outside the first tubular member 17 to form a second liquid passage 19 between the tube walls of the first tubular member and the second tubular member; the bottom end of the first tubular member 17 is closed, the tube wall has a plurality of first openings, and the top end has a first opening 20; the pipe wall of the second tubular part 18 is provided with a plurality of second holes, the bottom end of the second tubular part is provided with a second opening 21, and the top end of the second tubular part is connected with the top end of the first tubular part 17 in a sealing way; the space above the upper partition 15 is in fluid communication with the interior space of the mixing-reaction element 14 only through the first openings 20, the reaction feed zone 22 is in fluid communication with the second liquid passage 19 only through the second openings, and the space below the lower partition 16 is in fluid communication with the interior space of the mixing-reaction element 14 only through the second openings 21.

The alkylation multistage reactor comprises a mixing-reaction element with a specific structure, wherein at least part of first openings and at least part of second openings are oppositely arranged, and a liquid catalyst and a reaction feed in the mixing-reaction element enter a reaction zone in a second liquid channel in a mode of opposed jet through the oppositely arranged first openings and second openings respectively to carry out mixing reaction, so that the reaction feed and the liquid catalyst can be fully mixed and contacted in the reaction zone, the mixing and reaction efficiency is high, and the selectivity and the product quality are improved; the alkylation multistage reactor is internally provided with a plurality of mixing-reaction modules containing mixing-reaction elements to form a multistage reactor with graded feeding, and the alkylation multistage reactor and the method for carrying out alkylation reaction by using the alkylation multistage reactor can realize multistage reaction in one reactor, optimize the alkane-alkene ratio, improve the reaction efficiency, and reduce the investment and the occupied area of the reactor; meanwhile, in the alkylation multistage reactor disclosed by the invention, by arranging the interstage communicating pipe, a mixture of the liquid catalyst and the reaction product flowing out of the previous-stage module enters the second liquid channel for alkylation reaction through the reaction feeding area between the upper partition plate and the lower partition plate of the next-stage module, interstage reaction feeding enters the second liquid channel through the first liquid channel of the mixing-reaction element, the flow direction of the material is matched with the flow proportion of the material in the reactor, and the improvement on the efficiency of alkylation reaction is facilitated.

Interstage crossover tube 9 may be a crossover tube that communicates reaction product and liquid catalyst collection chamber 6 of a previous stage mixing-reaction module with reaction feed region 22 between an upper and lower partition of an adjacent next stage mixing-reaction module, in accordance with the present disclosure. Reaction products and liquid catalyst may pass from reaction products and liquid catalyst collection chamber 6 via this inter-stage communicating tube into reaction feed region 22 of the next adjacent stage mixing-reaction module and then into each mixing-reaction element 14. The top end opening of the interstage crossover tube 9 may be located at any horizontal position of the interstage diaphragm. Further, in order to promote the rapid and uniform distribution of the fluid in each mixing-reaction module 4, in a preferred embodiment of the present disclosure, as shown in fig. 4 to 5, the top end opening of the interstage communication tube 9 is located at the center of the interstage diaphragm 8, and the outer edge of the top end opening of the interstage communication tube 9 may be sealingly connected with the interstage diaphragm 8.

According to the present disclosure, the interstage diaphragm 8 may be a circular diaphragm installed horizontally in the space between adjacent mixing-reaction modules, and the outer edge of the circular diaphragm is sealingly fixed to the inner wall of the casing to isolate the fluids on the upper and lower sides of the interstage diaphragm 8. Above the interstage partition 8 is the reaction product and liquid catalyst collection chamber 6 of the previous stage mixing-reaction module, where the reaction product and liquid catalyst mixture leaving each mixing-reaction element 14 of the previous stage mixing-reaction module 4 is collected. Below the interstage diaphragm 8 is a reaction feed distribution chamber 7 of the stage mixing-reaction module, from which the reaction feed enters the individual mixing-reaction elements 14 of the stage mixing-reaction module.

According to the present disclosure, in order to realize a multi-stage reaction, further optimize an alkane-alkene ratio and improve reaction efficiency, preferably, the number of the mixing-reaction modules 4 in the housing 1 may be 2 to 12, and more preferably 9.

In order to further enhance the liquid-liquid mixing efficiency in each mixing-reaction module 4 according to the present disclosure, each mixing-reaction module 4 may preferably include a plurality of mixing-reaction elements 14 uniformly distributed in the feeding zone 22, and the number of mixing-reaction elements 14 may be determined by calculation according to the specific conditions of the alkylation reaction.

According to the present disclosure, the shape of the first tubular member 17 and the second tubular member 18 is not particularly required, and may be any shape of a conventional type, as long as it is ensured that at least a part of the first opening and at least a part of the second opening of the tube wall of the first tubular member 17 and the second tubular member 18 are opposite to each other, and the material of the first tubular member 17 and the second tubular member 18 may also be a conventional material, preferably a porous metal powder metallurgy or a mesh sintered tube. The first tubular member 17 is preferably a round or conical tube open at the upper end, and the second tubular member 18 is preferably a round or conical tube open at the lower end. For example, in one embodiment of the present disclosure, as shown in fig. 6, the first tubular member 17 is a circular tube with an open upper end, and the second tubular member 18 is a circular tube with an open lower end. In another embodiment of the present disclosure, as shown in fig. 7, the first tubular member 17 is a conical tube with an open upper end, the second tubular member 18 is a circular tube with an open lower end, and the tube diameter of the first tubular member gradually decreases from top to bottom. In the preferred embodiment described above, the first tubular member 17 and the second tubular member 18 are more efficient in liquid mixing through their respective openings and are easy to form.

According to the present disclosure, the tube walls of the first tubular member 17 and the second tubular member 18 may be respectively formed with uniform or non-uniform openings, the size and number of the openings may vary within a wide range, the diameter of the first openings may be 1-10 mm, preferably 3mm, and the sum of the opening areas of all the first openings in each mixing-reaction element 14 may account for 1-50%, preferably 5-40%, and most preferably 10-30% of the side wall area of the first tubular member; the diameter of the second openings may be 1 to 10mm, preferably 3mm, and the sum of the open areas of all the second openings in each mixing-reaction element 14 may account for 1 to 60%, preferably 10 to 50%, most preferably 20 to 40% of the side wall area of the second tubular member. The optimized opening area is more matched with the liquid flow in the reactor, thereby being beneficial to the mixing of the liquid in the reactor and the improvement of the reaction efficiency.

In a preferred embodiment of the present disclosure, as shown in fig. 2-3, the upper partition 15 is formed with the same number of circular holes as the mixing-reaction elements 14, the diameter of the circular holes is slightly larger than the outer diameter of the second tubular member 18 of the mixing-reaction elements 14, the top of each mixing-reaction element 14 is hermetically fixed in the corresponding circular hole of the upper partition 15, the first opening 20 at the top of the first tubular member 17 is concentric with the circular hole of the upper partition 15 and can be used as an inlet for the liquid catalyst or the mixture of the reaction product and the liquid catalyst, and the outer edge of the upper partition 15 is hermetically fixed to the inner wall of the alkylation multistage reactor shell 1. In addition to the first stage mixing-reaction module, the upper partition 15 of each of the other stages of mixing-reaction modules is further provided with a central circular hole, as shown in fig. 4 to 5, the size, the geometric shape and the horizontal position of the central circular hole correspond to the interstage communicating pipe 9, the lower opening edge of the interstage communicating pipe 9 is fixedly connected with the central circular hole of the upper partition of the next stage mixing-reaction module 4, and the interstage communicating pipe 9 is in fluid communication with the reaction feed region 22 of the next stage mixing-reaction module 4 through the central circular hole of the adjacent stage partition. The lower partition 16 is also provided with circular holes having the same number as the mixing-reaction elements 14, and the circular holes of the lower partition 16 are in one-to-one concentric correspondence with the horizontal positions of the circular holes of the upper partition 15. The mixing-reaction element 14 further comprises a closing cover plate, through which the top end of the second tubular member 18 is sealingly connected to the first tubular member 17, the outer edge of the closing cover plate being sealingly and fixedly connected to the circumference of the circular hole of the upper partition 15, and the second opening 21 of the second tubular member 18 being sealingly and fixedly connected to the circumference of the circular hole of said lower partition 16.

In a second aspect of the present disclosure, there is provided a process for carrying out an alkylation reaction using the alkylation multistage reactor provided in the first aspect of the present disclosure, the process comprising the steps of: the first stage reaction feed enters the alkylation multistage reactor from a first stage reaction feed inlet 10, then enters a first liquid channel of the first stage mixing-reaction module 4 through a first opening 20 of a first tubular member 17, and enters a second liquid channel 19 through a first opening; the liquid catalyst enters the reaction feeding area 22 of the first-stage mixing-reaction module 4 from the liquid catalyst inlet 11, the liquid catalyst in the reaction feeding area 22 enters the second liquid channel 19 through the second opening, and is mixed with the first-stage reaction feeding entering the second liquid channel 19 through the first opening in a counter-jet mode and is subjected to alkylation reaction, and the obtained mixture of the first-stage reaction product and the liquid catalyst flows out of the second opening 21 and enters the reaction feeding area 22 of the second-stage mixing-reaction module 4 through the interstage communication tube 9; passing the second stage reaction feed from interstage reaction feed inlet 12 into reaction feed distribution chamber 7, then through first opening 20 of first tubular member 17 into the first liquid passage of second stage mixing-reaction module 4, and then through the first opening into second liquid passage 19; the mixture of the first-stage reaction product and the liquid catalyst in the reaction feeding area 22 enters the second liquid channel 19 through the second opening, and is mixed with the second-stage reaction feed entering the second liquid channel 19 through the first opening in a counter-jet manner to carry out alkylation reaction, and the obtained mixture of the second-stage reaction product and the liquid catalyst flows out of the second opening 21, enters the reaction product and liquid catalyst collecting chamber 6, enters the reaction feeding area 22 of the third-stage mixing-reaction module 4 through the interstage communication pipe 9, or leaves the alkylation multistage reactor through the discharge port 13.

The alkylation method of the alkylation multistage reactor can enable the liquid catalyst and the reaction feed to enter the reaction zone through the pore channels respectively in a mode of 'opposed injection' in the mixing-reaction element for mixing reaction, can enable the reaction feed and the liquid catalyst to be fully mixed and contacted in the reaction zone, has high mixing and reaction efficiency, and improves the selectivity and the product quality; the alkylation multistage reactor comprises a plurality of mixing-reaction modules containing mixing-reaction elements, and can realize multistage reaction, thereby optimizing alkane-alkene ratio, improving reaction efficiency, and reducing reactor investment and floor area.

In accordance with the present disclosure, the liquid catalyst can be any of a variety of conventional liquid catalysts suitable for alkylation reactions, preferably an acidic ionic liquid catalyst.

According to the present disclosure, the reaction feed may be a mixture of hydrocarbons including olefins and paraffins, preferably a mixture of olefins containing C2 to C6 and isoparaffins containing C2 to C6, more preferably a C4 component containing olefins and paraffins. The alkane-olefin ratio of the reaction feed mixture can be 5-20, preferably 8-15, wherein the 'alkane-olefin ratio' refers to the molar ratio of isoparaffin to olefin in the mixture.

In a preferred embodiment of the present disclosure, as shown in fig. 8-9, a method for performing an alkylation reaction using an alkylation multistage reactor comprises the steps of:

(1) the first stage reaction feed enters the alkylation multistage reactor from a first stage reaction feed inlet 10, fills the upper space of the partition plate 15 on the first stage mixing-reaction module, enters the first liquid channel of the first stage mixing-reaction module 4 through the first opening 20 of the first tubular member 17, and enters the second liquid channel 19 through the first opening; (2) the liquid catalyst enters a reaction feeding area 22 between an upper partition plate and a lower partition plate of a first-stage mixing-reaction module 4 from a liquid catalyst inlet 11 arranged on the side surface of a reactor shell, the liquid catalyst in the reaction feeding area 22 enters a second liquid channel 19 through second openings of all mixing-reaction elements respectively, and is mixed with first-stage reaction feeding entering the second liquid channel 19 through the first openings in a counter-jet mode to carry out alkylation reaction; (3) the resulting first-stage reaction product and liquid catalyst mixture flows downward in the second liquid passage 19 and then exits the first-stage mixing-reaction module through the second openings 21 of the mixing-reaction elements, respectively; (4) in order to maintain the required alkane-to-alkene ratio for the reaction and to increase selectivity, it is necessary to supplement the second stage mixing-reaction module with part of the reaction feed, and the supplemented reaction feed enters the reaction feed distribution chamber 7 from the interstage reaction feed inlet 12 of the second stage, then enters the first liquid channel of the second stage mixing-reaction module 4 through the first opening 20 of the first tubular member 17, and then enters the second liquid channel 19 through the first opening; the mixture of the first-stage reaction product and the liquid catalyst leaving the first-stage mixing-reaction module enters a reaction product and liquid catalyst collecting chamber 6 and then enters a reaction feeding area 22 of the second-stage mixing-reaction module 4 through an interstage communicating pipe 9; and enters the second liquid channel 19 through the second opening of the mixing-reaction element, and is mixed with the second-stage reaction feed entering the second liquid channel 19 through the first opening in a counter-jet manner and is subjected to alkylation reaction, and then the reaction product and liquid catalyst mixture enters the reaction product and liquid catalyst collecting chamber 6, and then leaves the second-stage mixing-reaction module through the second-stage interstage communication tube 9 and enters the reaction feed region 22 of the third-stage mixing-reaction module 4; (5) the reaction product and liquid catalyst mixture leaving the last mixing-reaction module enter the lowermost space of the reactor and then leave the alkylation multistage reactor through the discharge port 13; (6) the mixture of reaction products and liquid catalyst leaving the reactor is sent to a subsequent separation facility for separation, so that the alkylation products and the liquid catalyst are separated, and the liquid catalyst is sent back to the alkylation multistage reactor for recycling.

The present disclosure is further illustrated with reference to the following examples, but the present disclosure is not to be construed as being limited thereto.

Example 1:

as shown in fig. 1-6, this example provides an alkylation multistage reactor with a built-in 4-stage mixing-reaction module. The method comprises the following steps: the reactor comprises a shell 1 with the inner diameter of 2800mm and the length of 6000mm, an upper seal head 2 and a lower seal head 3, wherein the upper seal head 2 and the lower seal head 3 are respectively welded at two ends of the shell 1 in a sealing manner to form a closed reactor shell, 4 groups of mixing-reaction modules 4 with the thickness of 600mm are installed in the shell 1, the upper seal head 2 is in an ellipsoid shape, the top of the upper seal head is provided with a first-stage reaction feeding inlet 10 of DN100, the upper part of the side surface of the shell 1 is provided with a liquid catalyst inlet 11 of DN200, the middle lower part of the side surface of the shell 1 is provided with 3 interstage reaction feeding inlets 12 of DN100, the lower seal head 3 is in an ellipsoid shape, and the bottom of the lower seal head;

3 interstage separators 8 are arranged between each stage of mixing-reaction modules, and each interstage separator is provided with a downward extending interstage communicating pipe 9 of DN 250; the height of the space of the reaction product and liquid catalyst collecting chamber 6 is 450mm, and the height of the space of the reaction feed distribution chamber 7 is 300 mm; the mixing-reaction module comprises 12 mixing-reaction elements 14, and an upper partition plate 15 and a lower partition plate 16 are respectively fixed with the shell in a sealing and welding way;

the mixing-reaction element 14 comprises a first tubular member 17 of equal diameter with an internal diameter of 40mm and a second tubular member 18 of internal diameter of 200mm, the first tubular member 17 being 350mm long, the diameter of the holes being 3mm and the aperture ratio being 25% of the surface area of the tube wall; the second fluid passage 19 has a radial spacing (the distance between the outer diameter of the first tubular member 17 and the inner diameter of the second tubular member 18) of 76 mm; the second tubular member 18 is a metal powder metallurgy fired tube with a porosity of 30% of the tube wall surface area; the diameter of the first opening 20 of the mixing-reaction element is 40mm and the diameter of the second opening 21 of the mixing-reaction element is 150 mm;

the liquid catalyst is an acidic ionic liquid catalyst containing chloride; the reaction feed composition (% by weight) is shown in table 1.

TABLE 1

Reaction feed Components	Content (wt%)
		Propane	0.08
Propylene (PA)	0.02
		Isobutane	43.0
N-butane	23.0
		Trans-2-butene	12.5
1-butene	12.5
		Isobutene	0.02
Cis-2-butene	7.9
		1, 3-butadiene	0.2
Others	0.78
		Total up to	100.0

Reaction conditions are as follows: the average reaction temperature was 20 ℃; the feed alkane to alkene ratio averaged 10.0 (molar ratio).

The yield of the alkylate was 81.5%.

Example 2:

the only difference from example 1 is that: the shape of the first tubular member 17 provided in the mixing-reaction element 14 is an inverted conical tube having a large top diameter and a small bottom diameter as shown in fig. 7, and the ratio of the upper and lower diameters is 1: 0.65, the length of the first tubular member 17 is 350mm, the diameter of the hole is 3mm, and the opening rate is 28 percent of the surface area of the tube wall;

the second fluid passage 19 is spaced radially above (the distance between the outer diameter of the first tubular member 17 and the inner diameter of the second tubular member 18) by 76 mm; the lower part is 87 mm; the second tubular member 18 is a metal mesh fired tube with a porosity of 30% of the surface area of the tube wall and the diameter of the second opening 21 of the mixing-reaction element is 150 mm.

The yield of the alkylate was 81.2%.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. An alkylation multistage reactor, characterized in that it comprises a housing (1), a mixing-reaction module (4), an interstage partition (8), a first stage reaction feed inlet (10), a liquid catalyst inlet (11), an interstage reaction feed inlet (12), and a discharge outlet (13);

the first-stage reaction feeding inlet (10) is positioned at the top of the shell (1), the discharging outlet (13) is positioned at the bottom of the shell (1), and a plurality of stages of mixing-reaction modules (4) are arranged in the shell (1) at intervals from top to bottom;

the mixing-reaction module (4) comprises an upper partition plate (15), a lower partition plate (16) and a plurality of mixing-reaction elements (14) which are arranged in parallel at intervals, the end edges of the upper partition plate (15) and the lower partition plate (16) are respectively and fixedly connected with the inner wall of the shell (1) in a sealing way so as to form a reaction feeding area (22) between the upper partition plate (15) and the lower partition plate (16), each mixing-reaction element (14) vertically penetrates through the reaction feeding area (22) and is respectively and fixedly connected with the upper partition plate (15) and the lower partition plate (16) in a sealing way, and the liquid catalyst inlet (11) is arranged on the shell (1) between the upper partition plate (15) and the lower partition plate (16) of the first-stage mixing-reaction module (4) positioned at the top end of the shell (1);

the interstage diaphragm (8) is arranged between the mixing-reaction modules (4) of the adjacent two stages along the horizontal direction, the end edge of the interstage diaphragm (8) is fixedly connected with the inner wall of the shell (1) in a sealing way, so that the interstage diaphragm (8) forms a reaction feed distribution chamber (7) with the adjacent upper diaphragm (15) and the inner wall of the shell (1), the interstage diaphragm (8) forms a reaction product and liquid catalyst collecting chamber (6) with the adjacent lower diaphragm (16) and the inner wall of the shell (1), and the interstage diaphragm (8) is provided with a communicating pipe (9) extending downwards, so that the reaction product and liquid catalyst collecting chamber (6) of the mixing-reaction modules (4) of the adjacent two stages are communicated with a reaction feed area (22); an interstage reaction feed inlet (12) is arranged on the shell (1) corresponding to each reaction feed distribution chamber (7);

each of said mixing-reaction elements (14) comprises a first tubular member (17) and a second tubular member (18) arranged axially; the inside of the first tubular member (17) is formed into a first liquid passage, and the second tubular member (18) is sleeved outside the first tubular member (17) to form a second liquid passage (19) between the tube walls of the first tubular member and the second tubular member; the bottom end of the first tubular member (17) is closed, the tube wall is provided with a plurality of first openings, and the top end of the first tubular member is provided with a first opening (20); the pipe wall of the second tubular part (18) is provided with a plurality of second open holes, the bottom end of the second tubular part is provided with a second opening (21), and the top end of the second tubular part is hermetically connected with the top end of the first tubular part (17); at least a portion of the first opening and at least a portion of the second opening of the mixing-reaction element (14) are oppositely disposed; the space above the upper partition (15) is in fluid communication with the interior space of the mixing-reaction element (14) only through the first opening (20), the reaction feed zone (22) is in fluid communication with the second liquid passage (19) only through the second opening, and the space below the lower partition (16) is in fluid communication with the interior space of the mixing-reaction element (14) only through the second opening (21).

2. The alkylation multistage reactor according to claim 1, wherein the top end opening of the interstage communication tube (9) is located in the center of the interstage diaphragm (8).

3. The alkylation multistage reactor according to claim 1, wherein the number of stages of the mixing-reaction module (4) is 2 to 12 stages.

4. The alkylation multistage reactor according to claim 1, wherein each of the mixing-reaction modules (4) comprises a plurality of mixing-reaction elements (14) distributed uniformly.

5. The alkylation multistage reactor according to claim 1, wherein the first tubular member (17) is a circular or conical tube open at the upper end and the second tubular member (18) is a circular or conical tube open at the lower end.

6. The alkylation multistage reactor according to claim 1, wherein the first apertures have a diameter of 1 to 10mm, and the sum of the aperture areas of all the first apertures in each mixing-reaction element (14) accounts for 1 to 50% of the side wall area of the first tubular member (17).

7. The alkylation multistage reactor according to claim 1, wherein the diameter of the second openings is 1-10 mm, and the sum of the open area of all the second openings in each mixing-reaction element (14) accounts for 1-60% of the side wall area of the second tubular member (18).

8. A method of conducting an alkylation reaction using the alkylation multistage reactor according to any one of claims 1 to 7, the method comprising the steps of:

-passing a first stage reaction feed from said first stage reaction feed inlet (10) into said alkylation multistage reactor, then through a first opening (20) of said first tubular member (17) into said first liquid passage of a first stage mixing-reaction module (4), and then through said first opening into said second liquid passage (19); passing liquid catalyst from said liquid catalyst inlet (11) into said reaction feed zone (22) of the first stage mixing-reaction module (4), liquid catalyst in said reaction feed zone (22) passing through said second opening into said second liquid channel (19), mixing and alkylating in counter-jet with first stage reaction feed passing through said first opening into said second liquid channel (19), and passing the resulting first stage reaction product and liquid catalyst mixture out of said second opening (21) through said inter-stage communication tube (9) into the reaction feed zone (22) of the second stage mixing-reaction module (4);

-passing a second stage reaction feed from said interstage reaction feed inlet (12) into a reaction feed distribution chamber (7) and then through a first opening (20) of said first tubular member (17) into said first liquid passage of a second stage mixing-reaction module (4) and through said first opening into said second liquid passage (19); the mixture of the first-stage reaction product and the liquid catalyst in the reaction feed area (22) enters the second liquid channel (19) through the second opening, is mixed with the second-stage reaction feed entering the second liquid channel (19) through the first opening in a mode of opposed jet and is subjected to alkylation reaction, and the obtained mixture of the second-stage reaction product and the liquid catalyst flows out of the second opening (21), enters a reaction product and liquid catalyst collecting chamber (6) and then enters the reaction feed area (22) of the mixing-reaction module (4) of the third stage through the interstage communication pipe (9), or leaves the alkylation multistage reactor through the discharge hole (13).

9. The method of claim 8, wherein the liquid catalyst is an acidic ionic liquid catalyst.

10. The method of claim 8, wherein the reaction feed is a mixture of C2-C6 olefins and C2-C6 isoparaffins.