CN112745887A

CN112745887A - Riser reactor for refining mixed aromatic hydrocarbon from crude heavy aromatic hydrocarbon

Info

Publication number: CN112745887A
Application number: CN201911037582.XA
Authority: CN
Inventors: 程键雄; 胡敏达
Original assignee: Zhejiang Meifu Petroleum Chemical Co ltd
Current assignee: Zhejiang Meifu Petroleum Chemical Co ltd
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2021-05-04

Abstract

The invention relates to a riser reactor for recycling mixed aromatic hydrocarbon of crude and heavy aromatic hydrocarbon, which comprises a riser reaction zone, a settler and a regenerator, wherein the riser reaction zone comprises a pre-lifting section, a cracking reaction section, an expanding section and a leading-in section which are communicated from bottom to top; the outlet of the leading-in section is connected with a coarse cyclone, the gas phase outlet of the coarse cyclone is connected with the inlet of a first cyclone separator in a settler, the lower part of the settler is provided with a stripping zone, and the lower end of the stripping zone is communicated with a regenerator; the side wall of the regenerator is provided with a to-be-regenerated inclined pipe, the side wall of the regenerator is also provided with an air inlet pipe, a second cyclone separator is arranged above the regenerator, and a lower plug valve is arranged below the regenerator. The method has the beneficial effects of improving the catalytic cracking capability of crude heavy aromatics, improving the yield of mixed aromatics and the like.

Description

Riser reactor for refining mixed aromatic hydrocarbon from crude heavy aromatic hydrocarbon

Technical Field

The invention relates to a riser reactor, in particular to a riser reactor for refining mixed aromatic hydrocarbon by crude heavy aromatic hydrocarbon, belonging to the technical field of petrochemical industry.

Background

The riser reactor is the core equipment on a catalytic cracking unit, which is a vertically installed tubular reactor having a length of about 40 meters and a diameter of about 0.5 meters to 1.0 meter. In the production process, raw oil is continuously fed into a tubular reactor to carry out cracking reaction at the high temperature of 500 ℃ and under the condition of a catalyst, and the catalytic cracking riser reactor generally comprises a bottom pre-lifting section, a cracking reaction section with middle feeding in contact and mixing, an upper reaction termination section and a tail end gas-solid rapid separation section according to the internal function. The raw oil is atomized and reacts at an average flow speed of about 10-15 m/s for about 3s, and research results show that the reaction result of catalytic cracking directly depends on the structure and design parameters of a riser reactor.

The Mixed Aromatics (Mixed Aromatics) are aromatic hydrocarbon mixtures containing C₅-C₉Low molecular weight organic compounds, etc., as well as some other impurities: sulfur, benzene, olefins, non-aromatics, and the like. The low-density mixed aromatic hydrocarbon can be used for gasoline blending, and can also be used for extracting and diluting pesticides, paints and other chemical products; the high-density mixed aromatic hydrocarbon (heavy aromatic hydrocarbon) is an important raw material of chemical products such as petroleum resin, solvent oil and the like, and can also be used for blending diesel oil, and the high-density mixed aromatic hydrocarbon (namely the heavy aromatic hydrocarbon) subjected to hydrogenation treatment can also be used for blending gasoline, but the cost is relatively high. Along with the high demand of downstream products, the global demand of mixed aromatics is also gradually increased, the capacity of the new domestic mixed aromatics technology is continuously increased, the industry competition is increased, and the improvement of the output value of the mixed aromatics is imperative.

Disclosure of Invention

The invention mainly aims at the problem of low yield of mixed aromatic hydrocarbon in catalytic cracking of the existing riser reactor, and provides the riser reactor for recycling the mixed aromatic hydrocarbon, which can improve the catalytic cracking capability of crude heavy aromatic hydrocarbon and the yield of the mixed aromatic hydrocarbon.

The purpose of the invention is mainly realized by the following scheme:

a riser reactor for refining mixed aromatic hydrocarbon from crude and heavy aromatic hydrocarbon comprises a riser reaction zone, a settler and a regenerator, wherein the riser reaction zone comprises a pre-lifting section, a cracking reaction section, an expanding section and a leading-in section which are communicated from bottom to top; the outlet of the leading-in section is connected with a coarse cyclone in the settler, the gas phase outlet of the coarse cyclone is connected with the inlet of a first cyclone separator in the settler, the lower part of the settler is provided with a stripping zone, a stripper is arranged in the stripping zone, and the lower end of the stripping zone is communicated with the regenerator through a tube to be regenerated; the side wall of the lower part of the regenerator is provided with a to-be-regenerated inclined pipe and is connected with the to-be-regenerated inclined pipe, the side wall of the regenerator is also provided with an air inlet pipe, a second cyclone separator is arranged above the inside of the regenerator, and a lower plug valve matched with the to-be-regenerated pipe is arranged below the inside of the regenerator. The catalyst entering the expanding section has enough buffering space, so that the pressure fluctuation of the regenerated inclined tube blanking can be reduced, the horizontal force action can be eliminated, the bias flow generated by the S-shaped motion track is eliminated, the fluidized steam is favorable for the catalyst to be distributed to the center of the riser reactor, the coarse heavy aromatic hydrocarbon and the catalyst are uniformly mixed and reacted, the yield of a target product is improved, and the agent-oil ratio of the expanding section can be increased.

Preferably, the regeneration inclined pipe and the to-be-regenerated inclined pipe are connected through a single-action slide valve, and steam is prevented from being connected with each other to the regenerator.

Preferably, a gas-phase outlet of the first cyclone separator is connected with a gas collection chamber, and the gas collection chamber is externally connected with an oil-gas separation pipeline and used for separating products after catalytic cracking of the crude heavy aromatics.

Preferably, the diameter of the expanding section is 2-3 times of the diameter of the cracking reaction section, the diameters of the pre-lifting section, the cracking reaction section and the introduction section are equal, and the diameter of the expanding section is larger than that of the pre-lifting section and smaller than that of the expanding section.

Preferably, the top of the regenerator is communicated with a flue gas outlet, so that flue gas of the regenerator after the spent catalyst is regenerated can be conveniently discharged.

Preferably, the regenerator is arranged coaxially with the settler and the regenerator is located below the settler.

Preferably, the gaseous medium of the stripper in the settler is steam.

Preferably, the number of the raw material inlets is 1-3, a plurality of raw material inlets can be arranged according to actual conditions, and the raw material inlets are uniformly distributed along the axis of the pre-lifting section.

Therefore, the invention has the following advantages: (1) the catalyst in the expanding section has enough buffer space, so that the pressure fluctuation of the regenerated inclined tube blanking can be reduced, and the action of the horizontal force of the regenerated inclined tube blanking can be eliminated, thereby eliminating the bias current generated by the S-shaped motion track; (2) the fluidized steam sprayed out of the fluidized ring flows upwards from an annular space formed by the pre-lifting steam pipe and the extraction pipe, and further supplies steam to the side wall of the riser reaction zone, so that the catalyst is favorably distributed to the center of the riser reaction zone, the raw oil and the catalyst are uniformly mixed and react, and the yield of a target product is improved; (3) the reaction zone of the expanding section is adopted, so that the higher reaction temperature and the catalyst-oil ratio at the bottom of the conventional riser reactor are reserved to increase the primary cracking reaction, the overcracking and the thermal cracking reaction at the top are inhibited, and the reaction time is prolonged at the lower reaction temperature at the middle upper part of the reactor; (4) the leading-in section is connected with the lower part of the diameter expanding section through a return pipe, and after entering the diameter expanding section, the oil gas is contacted with a supplementary catalyst which passes through the return pipe and is controlled by a return slide valve, so that the ratio of reactants to oil is increased, and the catalytic cracking effect is improved.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention;

fig. 2 is a schematic view of the structure of an enlarged section of the present invention.

Illustration of the drawings: 1-riser reaction zone, 2-settler, 3-regenerator, 4-pre-lifting section, 5-cracking reaction section, 6-expanding section, 7-leading-in section, 8-expanding section, 9-fluidization ring, 10-pre-lifting steam nozzle, 11-pre-lifting steam pipe, 12-leading-out pipe, 13-regeneration inclined pipe, 14-pre-lifting section, 15-coarse cyclone, 16-first cyclone separator, 17-stripping zone, 18-stripper, 19-waiting pipe, 20-waiting inclined pipe, 21-air inlet pipe, 22-second cyclone separator, 23-lower plug valve, 24-single-acting slide valve, 25-gas collection chamber, 26-oil-gas separation pipeline, 27-flue gas outlet, 28-return pipe and 29-return slide valve.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.

As shown in figures 1 and 2, the invention provides a technical scheme, a riser reactor for recycling mixed aromatic hydrocarbon of crude heavy aromatic hydrocarbon, which comprises a riser reaction zone 1, a settler 2 and a regenerator 3, wherein the riser reaction zone 1 comprises a pre-lifting section 4, a cracking reaction section 5, an expanding section 6 and an introduction section 7 which are connected from bottom to top in a through way, the lower part of the pre-lifting section 4 is also connected with an expanding section 8, a fluidization ring 9, a pre-lifting steam nozzle 10, a pre-lifting steam pipe 11 and an extraction pipe 12 are arranged in the expanding section 8, a pre-lifting steam pipe 11 is arranged in the extraction pipe 12, the upper part of the pre-lifting steam pipe 11 is provided with the pre-lifting steam nozzle 10, the fluidization ring 9 is arranged at the lower part of the pre-lifting steam nozzle 10, the side wall of the expanding section 8 is provided with a regeneration inclined pipe 13, the side wall above the pre-lifting section 4 is provided with a raw material inlet 14, the return pipe 28 is provided with a return slide valve 29; the diameter of the diameter expanding section 6 is 2 times of that of the cracking reaction section 5, the diameters of the pre-lifting section 4, the cracking reaction section 5 and the introduction section 7 are equal, and the diameter of the expanding section 8 is larger than that of the pre-lifting section 4 and smaller than that of the diameter expanding section 6.

The outlet of the leading-in section 7 is connected with a coarse cyclone 15 in the settler 1, the gas phase outlet of the coarse cyclone 15 is connected with the inlet of a first cyclone separator 16 in the settler 2, the gas phase outlet of the first cyclone separator 16 is connected with a gas collection chamber 25, the gas collection chamber 25 is externally connected with an oil-gas separation pipeline 26, the lower part of the settler 2 is provided with a stripping zone 17, a stripper 18 is arranged in the stripping zone 17, the gas medium of the stripper 18 in the settler 2 is water vapor, the lower end of the stripping zone 17 is communicated with a regenerator 3 through a pipe 19 to be regenerated, and the regenerator 3 and the settler 2 are coaxially arranged; the side wall of the lower part of the regenerator 3 is provided with a to-be-regenerated inclined pipe 20 and is connected with a regeneration inclined pipe 13 through a single-action slide valve 24, the side wall of the regenerator 3 is also provided with an air inlet pipe 21, a second cyclone separator 22 is arranged above the inside of the regenerator 3, a lower plug valve 23 matched with the to-be-regenerated pipe 19 for use is arranged below the inside of the regenerator 3, and the top of the regenerator 3 is communicated with a flue gas outlet 27.

The implementation of the riser reactor for the crude heavy aromatics recycling mixed aromatics of the invention comprises the following reaction processes: the high-temperature novel petroleum catalyst R-MGOO-MF/B flows into the expansion section 8 from the regenerator 3 through the inclined tube to be regenerated 20 and the inclined tube to be regenerated 13, forms a fluidization state under the action of the fluidization ring 9 at the bottom, the fluidization steam flowing out of the fluidization ring 9 keeps the catalyst at the bottom of the expansion section 8 in a dense-phase fluidization state, and carries and mixes the surrounding catalyst to form 65kg/m through the jet adsorption effect of high-speed steam flow sprayed from the pre-lifting steam nozzle 10³A high-speed catalyst flow with concentration, wherein the high-speed catalyst forms a high-speed catalyst flow stream under the lifting action of pre-lifting steam, flows through the outlet pipe 12, is injected into the cracking reaction section 5, is fully mixed with the coarse heavy aromatics injected from the raw material inlet 14, and then is subjected to catalytic cracking reaction in a high-temperature environment of 525-545 ℃, in order to enhance the modification effect, catalyst return pipes 28 are arranged on the introduction section 7 and the diameter expanding section 6, and part of catalyst is introduced from the introduction section above the low-temperature reaction zone and returns to the diameter expanding section 8, so that the catalyst-oil ratio in the catalyst return pipes is increased; reaction oil gas and a circulating catalyst enter a settler 2 through an introduction section 7, a coarse cyclone 15 and a first cyclone separator 16, the catalyst is separated from the oil gas and enters a stripping zone 17, the catalyst flows to a regenerator 3 from a spent tube 19 and is regenerated through regeneration medium air, the regenerated catalyst flows to an expansion section 8 through a spent inclined tube 20 and a regeneration inclined tube 13 for circulation, and flue gas generated in the regeneration process is discharged through a flue gas outlet 27.

Experiments show that when the catalyst-oil ratio is 5, the reaction time is 3s, and the cracking reaction temperature is 525 ℃, 535 ℃, 545 ℃, the proportion of mixed aromatic hydrocarbons with a dry point of 190 ℃ generated by cracking is 19.15%, 19.26%, 20.04%, the proportion of aromatic hydrocarbon components with higher added values in the mixed aromatic hydrocarbons is 5.79%, 5.88%, 6.33%, the mixed aromatic hydrocarbons can provide raw materials for a downstream aromatic hydrocarbon extraction device, and a novel petroleum catalyst R-MGOO-MF/B catalyst is adopted, so that the cracking capability of heavy aromatic hydrocarbons is improved, the coke yield is reduced, and the yield of the product mixed aromatic hydrocarbons is finally increased.

It is to be understood that the settler, regenerator, fluidizing ring, cyclone, stripper, lower plug valve, slide valve, etc. in this embodiment are all components known in the art or by those skilled in the art, the structure and principle of which are known to those skilled in the art through technical manuals or through routine experimentation, and it is to be understood that this embodiment is only for the purpose of illustration and is not intended to limit the scope of the invention, which will be defined by the appended claims after reading the teaching of the present invention.

Claims

1. A riser reactor for refining mixed aromatic hydrocarbon from crude heavy aromatic hydrocarbon is characterized in that: the riser reactor comprises a riser reaction zone (1), a settler (2) and a regenerator (3), wherein the riser reaction zone (1) comprises a pre-lifting section (4), a cracking reaction section (5), an expanding section (6) and a leading-in section (7) which are communicated from bottom to top, the lower part of the pre-lifting section (4) is also connected with an expanding section (8), a fluidization ring (9), a pre-lifting steam nozzle (10), a pre-lifting steam pipe (11) and a leading-out pipe (12) are arranged in the expanding section (8), a pre-lifting steam pipe (11) is arranged in the leading-out pipe (12), the upper part of the pre-lifting steam pipe (11) is provided with the pre-lifting steam nozzle (10), the fluidization ring (9) is arranged at the lower part of the pre-lifting steam nozzle (10), a regeneration inclined pipe (13) is arranged on the side wall of the expanding section (8), a raw material inlet (14) is arranged on the, the leading-in section (7) is connected with the lower part of the diameter expanding section (6) through a return pipe (28), and a return slide valve (29) is arranged on the return pipe (28); an outlet of the leading-in section (7) is connected with a coarse cyclone (15) in the settler (1), a gas phase outlet of the coarse cyclone (15) is connected with an inlet of a first cyclone separator (16) in the settler (2), a stripping zone (17) is arranged at the lower part of the settler (2), a stripper (18) is arranged in the stripping zone (17), and the lower end of the stripping zone (17) is communicated with the regenerator (3) through a tube (19) to be regenerated; the side wall of the lower part of the regenerator (3) is provided with a to-be-regenerated inclined pipe (20) and is connected with a regenerated inclined pipe (13), the side wall of the regenerator (3) is also provided with an air inlet pipe (21), a second cyclone separator (22) is arranged above the inside of the regenerator (3), and a lower plug valve (23) matched with the to-be-regenerated pipe (19) is arranged below the inside of the regenerator (3).

2. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 1, wherein: the regeneration inclined pipe (13) and the to-be-regenerated inclined pipe (20) are connected through a single-action slide valve (24).

3. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 1, wherein: and a gas-phase outlet of the first cyclone separator (16) is connected with a gas collection chamber (25), and the gas collection chamber (25) is externally connected with an oil-gas separation pipeline (26).

4. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 1, wherein: the diameter of the diameter expanding section (6) is 2-3 times of that of the cracking reaction section (5).

5. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 4, wherein: the diameters of the pre-lifting section (4), the cracking reaction section (5) and the leading-in section (7) are equal.

6. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 5, wherein: the diameter of the expanding section (8) is larger than that of the pre-lifting section (4) and smaller than that of the expanding section (6).

7. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 1, wherein: the top of the regenerator (3) is communicated with a flue gas outlet (27).

8. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 7, wherein: the regenerator (3) and the settler (2) are coaxially arranged, and the regenerator (3) is positioned below the settler (2).

9. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 8, wherein: the gaseous medium of the stripper (18) in the settler (2) is steam.

10. The riser reactor for the primary heavy aromatics recycle of mixed aromatics according to claim 1, wherein: the number of the raw material inlets (14) is 1-3.