A catalyst fluidized attrition classification method

Abstract

The present invention discloses a catalyst fluidized wear and grading method, comprising the following equipment, the equipment is composed of a catalyst storage system, a catalyst fluidized wear system, and a catalyst grading system; the catalyst storage system is composed of a catalyst storage tank and a carrier gas pipeline; the catalyst fluidized wear system is composed of a fluidized wear reactor, a catalyst feed pipe, and an auxiliary fluidized pipeline, a catalyst primary collision wear zone is set on the catalyst feed pipe, and a catalyst secondary collision wear zone is formed at the catalyst feed pipe outlet and the bottom of the fluidized wear reactor; the catalyst grading system is composed of a primary cyclone separator and a secondary cyclone separator. The equipment is used to perform fluidized wear and grading on catalyst particles to reduce the wear of the catalyst in the reaction device, reduce the generation of fine powder, reduce the solid content of the oil slurry in the catalytic cracking device, and reduce system failures caused by fine powder; and through the optimization of particle size distribution, the long-term stable operation of the catalytic cracking device is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a catalyst fluidized attrition classification method. Background Art

[0002] Catalytic cracking is an important means of converting heavy oil into light oil. Maintaining good activity and selectivity of the catalyst is the key to ensuring the normal operation of the device and improving efficiency. The catalyst is deactivated and revived by circulating between the reactor and the regenerator. However, the wear of the catalyst by the raw oil and the nozzle in the reactor, the wear between the catalyst particles in the regenerator, and the wear between the particles and the equipment can easily lead to a smaller catalyst particle size, and the generated catalyst fine powder enters the flue gas and oil gas. The increase in the content of catalyst fine powder in the flue gas and oil gas can easily cause catalyst loss, and a large amount of catalyst loss will cause a reduction in catalyst reserves and fluidization disorders, affecting the normal production of the device. The damaged catalyst fine powder enters the flue gas and oil slurry pipeline system, accelerating the wear of equipment and pipelines, thereby affecting the safe production of the device; at the same time, it leads to excessive catalyst consumption and increased costs. Therefore, the particle size distribution of the fresh catalyst, especially the content of fine powder with a particle size of less than 40 microns and the mechanical strength of the catalyst often determine the operating status of the device and the consumption of the catalyst.

[0003] Generally, catalytic cracking catalysts are produced industrially using the spray drying molding process. During the preparation process, many factors such as raw material properties, catalyst formulation, spray conditions (temperature, nozzle pressure, etc.), roasting, hydrothermal treatment, etc. will affect the appearance, particle size distribution and mechanical strength of the fresh catalyst. Therefore, industrially produced catalyst product particles often have problems such as depression, cracks, and adhesion. These problematic catalyst particles are very likely to undergo thermal collapse under hydrothermal conditions and are also easily worn and broken during the fluidization process, producing a large amount of fine powder; on the other hand, during the spray molding process, the catalyst particle size is normally distributed, and catalyst particles below 40 microns often account for 10-30% of the total weight of the catalyst. When the catalyst preparation or spray device operation is unstable, the proportion of fine powder will further increase. After the fine powder in the catalyst enters the system, it will cause the load of the three cyclones to increase; if the separation effect is not good, it will also cause a high catalyst content at the inlet of the smoke exhaust fan, affecting the long-term operation of the smoke exhaust fan. In terms of the settler, when the fine powder content in the catalyst is high, it is easy to be carried into the distillation tower by oil and gas, causing the catalyst in the oil slurry to increase or the solid content of the oil slurry to increase, reducing the operating cycle of the oil slurry pump, and posing a major hidden danger to the safe operation of the device.

[0004] In view of the above problems, the conventional method is to reduce the content of fine powder in the catalyst by adjusting the catalyst production process, optimizing the formula, circulating fine powder and other measures. For example, CN201510472307.6 discloses a method for preparing FCC catalysts that reduces the product of non-in-situ crystallization reaction. By controlling the crystallization reaction under different temperature gradients, the generation of fine powder in the synthetic FCC catalyst can be effectively reduced. However, while this method increases the mechanical strength of the catalyst, it is accompanied by problems such as small catalyst pore volume and low active component content, which will cause a loss in catalyst reaction performance.

[0005] There are also methods for reducing catalyst fines in the catalytic cracking unit system. Patent CN201610384174.1 discloses a recovery device and recovery method for catalytic cracking catalyst fines. The fines are collected by a fines collector before entering the reactor after a continuous regeneration device. After effectively treating the contaminated metals, the double-gel method is ground and slurried to regenerate a catalytic cracking (FCC) catalyst that meets the normal particle size distribution. Patent CN200480020352.8 discloses a method for contacting a quenched outflow gas stream from an oxygen-containing compound to an olefin conversion process with a liquid to capture catalyst fines, which is used to remove fines during the reaction process. CN103611581A discloses a method for recovering catalyst fines for re-granulation, which is applicable to a fluidized bed system for alcohol ether to olefins, where the catalyst fines are collected by means of a dust collector, and the collected catalyst fines directly enter the catalyst granulation process. The above method often requires adding a separate device inside the catalytic cracking unit for collecting fines, which will increase the complexity and cost of the device, and affect the circulating fluidization of the catalyst in the device.

[0006] In addition, in order to reduce fine powder in the catalyst, CN104858044B discloses a method for grading a catalyst carrier, which performs cyclone grading on a dispersion containing a catalyst carrier, and obtains a dispersion containing a target catalyst carrier in a target particle size range by controlling the conditions of the cyclone grading. CN206009234U discloses a negative pressure fluidized windmill type physical grading device for reforming catalysts. Although the above method has a certain particle grading effect, it is not suitable for catalytic cracking catalysts with small particle sizes, and cannot achieve the effect of catalyst pre-wear.

[0007] In summary, in order to solve the problem that catalytic cracking catalysts in industrial applications contain a large amount of fine powder and have poor appearance, which easily lead to the generation of fine powder in the catalyst, the existing solutions and technologies have the following problems: 1) There is no device and method to specifically solve the problem of catalyst wear; 2) In order to improve the wear resistance, the catalytic performance of the catalyst is sacrificed, but the problem of excessive catalyst fine powder cannot be avoided; 3) The existing grading device is not suitable for the grading treatment of catalytic cracking catalysts, and the grading effect is not ideal. Summary of the invention

[0008] In view of the above problems, the present invention provides a catalyst fluidized attrition classification method, which performs fluidized attrition pretreatment on industrial catalysts, abrasion treatment is performed on the particles in the catalyst that are prone to produce fine powder in advance, and then undergoes multi-stage cyclone classification to control the particle size of the catalyst particles within a range suitable for long-term operation of a catalytic cracking unit, thereby achieving the purpose of reducing the fine powder content in the catalyst and ensuring the smooth operation of the catalytic cracking unit.

[0009] The present invention adopts the following technical solution:

[0010] A catalyst fluidized attrition classification method, comprising the following equipment and process:

[0011] The equipment includes a catalyst storage system, a catalyst fluidized attrition system and a catalyst grading system which are connected in sequence; the catalyst storage system includes a catalyst storage tank and a carrier gas pipeline, a discharge valve is provided at the bottom of the catalyst storage tank, and is connected to the carrier gas pipeline through the discharge valve; a fast carrier gas pipeline is also connected to the carrier gas pipeline, and an outlet valve is provided on the fast carrier gas pipeline; the catalyst fluidized attrition system includes a fluidized attrition reactor, a catalyst feed pipe is plugged into the side wall of the fluidized attrition reactor, one end of the catalyst feed pipe is connected to the carrier gas pipeline, and the other end extends vertically downward to the bottom of the fluidized attrition reactor and there is a gap between the catalyst feed pipe and the bottom of the fluidized attrition reactor; a first auxiliary fluidized pipeline and a second auxiliary fluidized pipeline are also plugged into the side wall of the fluidized attrition reactor, and the first auxiliary fluidized pipeline and the second auxiliary fluidized pipeline are symmetrically distributed along the central axis of the fluidized attrition reactor; the catalyst grading system includes a plurality of cyclone separators connected in series in sequence, and the first cyclone separator is connected to the fluidized attrition reactor.

[0012] The process comprises the following steps:

[0013] S1: Open the discharge valve and the gas outlet valve, and transport the catalyst particles into the fluidized abrasion reactor through the fluidizing gas in the carrier gas pipeline and the fast carrier gas pipeline. The ratio of the superficial gas velocity of the carrier gas pipeline to the fast carrier gas pipeline is 1:1.5-5;

[0014] S2: After the catalyst particles collide and wear in the catalyst feed pipe, they rush into the bottom of the fluidized attrition reactor for further collision and wear. After two stages of collision and wear, the catalyst particles gradually accumulate at the bottom of the fluidized attrition reactor to form a catalyst bed.

[0015] S3: closing the gas outlet valve to keep the gas velocity and flow rate of the fluidizing gas in the carrier gas pipeline constant to further fluidize the catalyst;

[0016] S4: opening the first auxiliary fluidizing pipeline and the second auxiliary fluidizing pipeline, and under the joint action of multiple fluidizing gases in the auxiliary fluidizing pipeline and the catalyst feed pipe, ensuring uniform contact between the catalyst particles and the fluidizing gas, ensuring uniform wear of the catalyst particles;

[0017] S5: After the attrition is completed, the outlet valve is opened, and the gas velocity of the fluidizing gas in the first auxiliary fluidizing line and the second auxiliary fluidizing line is appropriately increased to be able to blow up the catalyst particles, and the catalyst particles in the fluidized attrition reactor are quickly transported into the catalyst grading system for grading to obtain catalyst particles of different particle size ranges.

[0018] The beneficial effects of the present invention are as follows:

[0019] By pre-treating the industrial samples of catalytic cracking catalysts, the catalyst particles with poor mechanical strength and easy to wear and produce fine powder (such as multiple microspheres sticking together, irregular shape, poor sphericity, defects such as depressions and cracks on the particle surface) and large-size catalyst particles are pre-treated to improve the strength of the catalyst. After the pre-treatment, the catalyst is passed through a multi-stage cyclone separator, and the pressure and gas velocity of the separator are strictly controlled. The worn catalyst is classified according to the particle size to remove the fine powder in the catalyst, which improves the fluidity of the fluidization, circulation and regeneration process of the catalytic cracking unit, improves the operating stability of the catalytic cracking unit, and has important guiding significance for the long-term recycling of catalytic cracking catalysts. At the same time, the fluidized attrition classification device has the characteristics of simple operation, good classification effect, and strong operation continuity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a catalyst fluidized attrition classification device of the present invention;

[0021] Figure 2 This is an electron microscope photo of a comparative example of the present invention;

[0022] Figure 3 This is an electron microscope photograph of Example 1 of the present invention;

[0023] Figure 4 This is an electron microscope photograph of Example 2 of the present invention;

[0024] Figure 5 This is an electron microscope photograph of Example 3 of the present invention;

[0025] In the figure, 1-catalyst storage tank, 2-unloading valve, 3-carrier gas pipeline, 4-gas outlet valve, 5-fast carrier gas pipeline, 6-fluidized abrasion reactor, 7-first auxiliary fluidized pipeline, 8-secondary collision and abrasion zone, 9-second auxiliary fluidized pipeline, 10-catalyst feed pipe, 11-primary collision and abrasion zone, 12-catalyst delivery pipe, 13-primary cyclone separator, 14-secondary cyclone separator, 15-exhaust pipeline. DETAILED DESCRIPTION

[0026] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1 As shown, the equipment used in the catalyst fluidized attrition classification method of the present invention includes a catalyst storage system, a catalyst fluidized attrition system and a catalyst classification system which are connected in sequence.

[0028] The catalyst storage system includes a catalyst storage tank 1 and a carrier gas pipeline 3. A discharge valve 2 is provided at the bottom of the catalyst storage tank 1, and is connected to the carrier gas pipeline 3 through the discharge valve 2. A fast carrier gas pipeline 5 is also connected to the carrier gas pipeline 3, and an outlet valve 4 is provided on the fast carrier gas pipeline 5.

[0029] The catalyst fluidized attrition system includes a fluidized attrition reactor 6, and a catalyst feed pipe 10 is inserted into the side wall of the fluidized attrition reactor 6. One end of the catalyst feed pipe 10 is connected to the carrier gas pipeline 3, and the other end extends vertically downward to the bottom of the fluidized attrition reactor 6 and there is a gap between the bottom of the fluidized attrition reactor 6; a first auxiliary fluidized pipeline 7 and a second auxiliary fluidized pipeline 9 are also inserted into the side wall of the fluidized attrition reactor 6, and the first auxiliary fluidized pipeline 7 and the second auxiliary fluidized pipeline 9 are symmetrically distributed along the central axis of the fluidized attrition reactor 6.

[0030] When in use, there is no special requirement for the configuration of the fluidized attrition reactor 6, and conventional columnar, conical or truncated cone reactors can achieve the fluidized attrition effect of the catalyst. Preferably, the fluidized attrition reactor 6 is conical in the upper part, columnar in the middle part, and inverted conical in the bottom, and the ratio of the diameter to the vertical height of the fluidized attrition reactor 6 is 1:2~5; the bottom of the inverted conical section of the fluidized attrition reactor 6 is a secondary collision wear zone 8, and the vertical cross-section of the secondary collision wear zone 8 is an elliptical arc, and the long axis of the elliptical arc is perpendicular to the outlet direction of the catalyst feed pipe 10, and the ratio of the long axis to the short axis is 1~3:1.

[0031] The bottom of the fluidized attrition reactor 6 is designed to be an inverted cone in order to quickly reduce the linear velocity of the catalyst particles after the catalyst particles change direction, thereby forming a dense bed of catalyst at the bottom of the reactor, strengthening the wear between the particles, and grinding off the small particles adhering to the catalyst, while achieving the purpose of improving the sphericity of the catalyst; the middle part is designed to be columnar, which is conducive to forming a uniform dense fluidized bed in the reactor, reducing the height of the dilute phase zone produced by particle entrainment at the interface of the dense bed, thereby improving the uniformity of catalyst wear and improving the processing efficiency; the top is designed to be conical, which is conducive to quickly transforming the catalyst bed from a turbulent bed to a conveying bed when the catalyst is transported out of the reactor with the fluidizing gas, thereby achieving the purpose of quickly transporting the catalyst, while reducing the dead zone inside the catalyst bed, and improving the fluidization quality and processing efficiency.

[0032] The catalyst feed pipe 10 can enter the fluidized attrition reactor 6 from any position, such as the side wall, the bottom, etc., as long as the catalyst can be transported into the fluidized attrition reactor 6. Preferably, the catalyst feed pipe 10 is L-shaped, one end of which is plugged into the upper side wall of the fluidized attrition reactor 6, and the other end of which extends vertically along the central axis of the fluidized attrition reactor 6 to above the secondary collision wear zone 8; the bent section of the catalyst feed pipe 10 is the primary collision wear zone 11.

[0033] The function of the primary collision wear zone 11 is: on the one hand, the catalyst particles entering the fluidized attrition reactor 6 at high speed collide strongly with the inner wall of the primary collision wear zone 11 to achieve the effect of collision wear; on the other hand, the direction of the catalyst and the airflow is changed to transport the catalyst into the fluidized attrition reactor 6. In order to increase the collision efficiency and reduce the interference of the reflection of the catalyst particles after the collision on the forward high-speed catalyst flow, the primary collision wear zone 11 is curved in an arc shape, and the vertical section of the primary collision wear zone 11 is an involute, and the r of the involute is 1 to 2 times the radius of the catalyst feed pipe 10, and the angle of the involute is preferably 70 to 90°. The function of the secondary collision wear zone 8 is similar to that of the primary collision wear zone 11, both of which play a role in collision wear while changing the direction of the catalyst flow.

[0034] At the same time, in order to uniformly fluidize and transport the catalyst particles in the fluidized attrition reactor 6, a plurality of first auxiliary fluidized pipelines 7 and second auxiliary fluidized pipelines 9 are arranged on the side wall of the fluidized attrition reactor 6. The first auxiliary fluidized pipelines 7 and the second auxiliary fluidized pipelines 9 can be arranged on the side wall of the columnar section in the middle of the fluidized attrition reactor 6, or on the side wall of the bottom inverted cone section, both of which can achieve the above purpose. Preferably, the total number of the first auxiliary fluidized pipelines 7 and the second auxiliary fluidized pipelines 9 is 2 to 12, and they are symmetrically distributed along the central axis of the fluidized attrition reactor 6 on the side wall of the bottom inverted cone section. The angle between the first auxiliary fluidized pipelines 7 and the second auxiliary fluidized pipelines 9 and the bottom inverted cone side wall of the fluidized attrition reactor 6 is 60 to 90°; the intersection of the first auxiliary fluidized pipelines 7 and the second auxiliary fluidized pipelines 9 and the bottom inverted cone side wall of the fluidized attrition reactor 6 is located at 1 / 3 to 2 / 3 of the vertical height of the bottom inverted cone section.

[0035] The catalyst classification system is composed of a plurality of cyclone separators connected in series. Preferably, the catalyst classification system is composed of a primary cyclone separator 13 and a secondary cyclone separator 14 connected in series. The primary cyclone separator 13 is connected to the fluidized attrition reactor 6 through a catalyst delivery pipe 12, and is connected in series with the secondary cyclone separator 14. The outlet of the secondary cyclone separator 14 is connected to an exhaust line 15. The present invention has no special requirements for the structure of the primary cyclone separator 13 and the secondary cyclone separator 14, and conventional cyclone separators in the art can achieve the purpose of classification.

[0036] The process comprises the following steps:

[0037] S1: Open the discharge valve 2 and the outlet valve 4, and transport the catalyst particles to the fluidized attrition reactor 6 through the catalyst feed pipe 10 by the fluidizing gas in the carrier gas pipeline 3 and the fast carrier gas pipeline 5, and the ratio of the superficial gas velocity of the carrier gas pipeline 3 to the fast carrier gas pipeline 5 is 1:1.5-5;

[0038] S2: After the catalyst particles collide and wear in the primary collision and wear zone 11 in the catalyst feed pipe 10, they rush into the secondary collision and wear zone 8 at the bottom of the fluidized attrition reactor 6 for further collision and wear. After the two-stage collision and wear, the catalyst particles gradually accumulate at the bottom of the fluidized attrition reactor 6 to form a catalyst bed.

[0039] Preferably, the instantaneous linear velocity of the catalyst particles and the airflow through the secondary collision wear zone 8 is not less than 3 m / s, and the more preferred instantaneous linear velocity is not less than 5 m / s; the instantaneous linear velocity of the catalyst particles and the airflow through the primary collision wear zone 11 is not less than 5 m / s, and the more preferred instantaneous linear velocity is not less than 10 m / s;

[0040] S3: closing the gas outlet valve 4 to keep the gas velocity and flow rate of the fluidizing gas in the carrier gas pipeline constant to further fluidize the catalyst particles;

[0041] S4: opening the first auxiliary fluidizing pipeline 7 and the second auxiliary fluidizing pipeline 9, and under the joint action of multiple fluidizing gases in the auxiliary fluidizing pipeline and the catalyst feed pipe, ensuring uniform contact between the catalyst particles and the fluidizing gas, ensuring uniform wear of the catalyst particles;

[0042] S5: After the attrition is completed, the outlet valve 4 is opened, and the gas velocity of the fluidizing gas in the first auxiliary fluidizing pipeline 7 and the second auxiliary fluidizing pipeline 9 is appropriately increased to be able to blow up the catalyst particles, and the catalyst particles in the fluidized attrition reactor are quickly transported into the catalyst grading system for grading to obtain catalyst particles of different particle size ranges.

[0043] In order to facilitate the entry of catalyst particles into the catalyst classification system, the gas flow rate and pressure in the first auxiliary fluidized pipeline 7 and the second auxiliary fluidized pipeline 9 are preferably equal, and they are increased and decreased synchronously; in order to achieve the purpose of optimizing the fluidization state of the catalytic cracking unit, reducing catalyst fines, and reducing the solid content of the oil slurry through the catalyst classification system, the preferred catalyst particle size range obtained by the first-level cyclone separator 13 is 30-150 microns, the catalyst particle size range obtained by the second-level cyclone separator 14 is not more than 45 microns, and the fine powder particle size discharged from the emptying pipeline 15 is not more than 10 microns. Further preferably, the catalyst particle size obtained by the first-level cyclone separator 13 is 40-130 microns, the catalyst particle size range obtained by the second-level cyclone separator 14 is 8-40 microns; the fine powder particle size discharged from the emptying pipeline 15 is not more than 8 microns.

[0044] The present invention has no special requirements on the type and temperature of the fluidizing gas in the carrier gas pipeline 3 and the fast carrier gas pipeline 5. Conventional fluidizing gases can play the role of fluidization, abrasion, and classification, such as air, nitrogen, water vapor, helium, etc. It can be one of the conventional fluidizing gases or a mixture of concentrated gases. In order to further strengthen the abrasion of the catalyst and reduce the fluidization abrasion time, it is preferred to use one or more of high-temperature nitrogen, air, and superheated water vapor as the fluidizing medium, and the temperature of the fluidizing medium is 50~1000℃. More preferably, the temperature of the fluidizing gas is 100~800℃. If the on-site conditions cannot make the gas reach the required temperature conditions, a heating device can be set on the outer wall of the fluidized abrasion reactor 6 to ensure that the catalyst bed is kept at a constant temperature within this temperature range.

[0045] The following is a specific example of using the method of the present invention to treat catalyst particles.

[0046] Comparative Example

[0047] A commercially available industrial catalytic cracking catalyst product was used as a comparative example without any wear pretreatment. Its particle size distribution, wear index and electron microscope test were tested. The results are listed in Tables 1 and Figure 2 .

[0048] Example 1

[0049] according to Figure 1 The catalyst fluidized attrition and classification device is shown in the figure, which is composed of a catalyst storage system, a catalyst fluidized attrition system, and a catalyst classification system. The catalyst storage system is composed of a catalyst storage tank, a carrier gas pipeline, and a fast carrier gas pipeline, and the ratio of the superficial gas velocity of the carrier gas pipeline 3 to the fast carrier gas pipeline 5 is 1:2. The catalyst fluidized attrition system is composed of a fluidized attrition reactor 6, a catalyst feed pipe 10, a first auxiliary fluidized pipeline 7, and a second auxiliary fluidized pipeline 9. The catalyst feed pipe 10 is connected to the carrier gas pipeline 3 of the catalyst storage system, and the catalyst feed pipe 10 enters from the upper side wall of the fluidized attrition reactor and extends vertically along the central axis to the bottom of the fluidized attrition reactor 6. An arc-shaped primary collision and wear zone 11 is set at the corner of the catalyst feed pipe 10, and the vertical section of the primary collision and wear zone 11 is an involute, and the radius of the involute is 1.5 times the radius of the catalyst feed pipe, and the angle of the involute is preferably 80°. The instantaneous linear speed of the catalyst particles and the airflow passing through the primary collision and wear zone 11 is 10m / s. The lower part of the fluidized attrition reactor 6 is in an inverted cone shape, the middle part is columnar, and the upper part is conical; the ratio of its diameter to vertical height is 1:4. A secondary collision wear zone 8 is set at the bottom of the fluidized attrition reactor 6 at a position corresponding to the outlet of the catalyst feed pipe 10. The secondary collision wear zone 8 is concave spherical, and the vertical cross-section is an elliptical arc. The ratio of the major axis to the minor axis of the elliptical arc is 3:1. The instantaneous linear velocity of the catalyst particles and the airflow through the secondary collision wear zone 8 is 8m / s. Two first auxiliary fluidized pipelines 7 and second auxiliary fluidized pipelines 9 symmetrically distributed along the central axis are set on the bottom inverted cone side wall of the fluidized attrition reactor 6. The angle between the auxiliary fluidized pipeline and the bottom inverted cone side wall of the fluidized attrition reactor 6 is 70°, and the intersection with the bottom inverted cone side wall is located at 1 / 2 of the vertical height of the bottom inverted cone.

[0050] The catalyst classification system is composed of a primary cyclone separator 13 and a secondary cyclone separator 14 connected in series. The primary cyclone separator can obtain catalyst particles of 40 to 130 microns, and the secondary cyclone separator can obtain catalyst particles of 8 to 40 microns; the particle size of fine powder in the exhaust pipeline 15 is not greater than 8 microns. The fluidizing gas uses high-temperature nitrogen at a temperature of 700°C.

[0051] The same commercially available industrial catalytic cracking catalyst product as in Comparative Example 1 was pretreated on the fluidized attrition classification device described in Example 1, and its particle size distribution, attrition index and electron microscope test were tested. The results are listed in Tables 1 and Figure 3 .

[0052] Example 2

[0053] according to Figure 1The catalyst fluidized wear and grading device is shown in the figure. The difference from Example 1 is that there is no fast carrier gas pipeline 5 in Example 2, and only a primary collision wear zone 11 is set at the corner of the catalyst feed pipe, and no secondary collision wear zone 8 is set. The vertical section of the primary collision wear zone 11 is an involute, the radius of the involute is twice the radius of the catalyst feed pipe, and the angle of the involute is preferably 90°. The instantaneous linear speed of the catalyst particles and the airflow passing through the primary collision wear zone is 5m / s. The fluidizing gas uses high-temperature steam at a temperature of 500°C. The rest is the same as Example 1.

[0054] The same commercially available industrial catalytic cracking catalyst product as in Comparative Example 1 was pretreated on the fluidized attrition classification device described in Example 2, and its particle size distribution, attrition index and electron microscope test were tested. The results are listed in Tables 1 and Figure 4 .

[0055] Example 3

[0056] according to Figure 1 The catalyst fluidized attrition classification device is shown in the figure. The difference from Example 1 is that Example 3 does not set a primary collision and abrasion zone at the corner of the feed pipeline, but only sets a secondary collision and abrasion zone 8. The vertical cross section of the secondary collision and abrasion zone is an elliptical arc, and the ratio of the major axis to the minor axis of the elliptical arc is 2:1. The instantaneous linear speed of the catalyst particles and the airflow passing through the secondary collision and abrasion zone is 10m / s. The rest is the same as Example 1.

[0057] The same commercially available industrial catalytic cracking catalyst product as in Comparative Example 1 was pretreated on the fluidized attrition classification device described in Example 2, and its particle size distribution, attrition index and electron microscope test were tested. The results are listed in Tables 1 and Figure 5 .

[0058] Table 1 Catalyst particle size distribution and attrition index

[0059]

[0060] It can be seen from Table 1 above that, compared with the comparative example, Example 1 significantly reduces the content of fine powder of 0-40 μm in the catalyst, and at the same time, large particles larger than 149 μm are significantly reduced, the wear index of the catalyst is significantly improved, and the electron microscope photograph also shows a good particle size distribution and sphericity. This is mainly because the catalyst fluidized attrition classification device can wear irregular catalyst particles in the catalyst and remove them in the form of fine powder.

Claims

1. A catalyst fluidized attrition classification method, characterized in that: Including the following equipment and processes: Equipment: including a catalyst storage system, a catalyst fluidized attrition system and a catalyst grading system which are connected in sequence; The catalyst storage system comprises a catalyst storage tank (1) and a carrier gas pipeline (3); a discharge valve (2) is provided at the bottom of the catalyst storage tank (1) and is connected to the carrier gas pipeline (3) via the discharge valve (2); a fast carrier gas pipeline (5) is also connected to the carrier gas pipeline (3), and a gas outlet valve (4) is provided on the fast carrier gas pipeline (5); The catalyst fluidized attrition system comprises a fluidized attrition reactor (6), the fluidized attrition reactor (6) having a conical upper portion, a columnar middle portion, and an inverted conical bottom portion, and a catalyst feed pipe (10) is plugged into the side wall of the fluidized attrition reactor (6), one end of the catalyst feed pipe (10) is connected to the carrier gas pipeline (3), and the other end of the catalyst feed pipe (10) vertically extends downward to the bottom of the fluidized attrition reactor (6) and there is a gap between the catalyst feed pipe (10) and the bottom of the fluidized attrition reactor (6); a first auxiliary fluidized pipeline (7) and a second auxiliary fluidized pipeline (9) are also plugged into the side wall of the fluidized attrition reactor (6), and the first auxiliary fluidized pipeline (7) and the second auxiliary fluidized pipeline (9) are symmetrically distributed along the central axis of the fluidized attrition reactor (6); The catalyst classification system comprises a plurality of cyclone separators connected in series, and the first cyclone separator is connected to the fluidized attrition reactor (6); Process: The following steps are included: S1: Open the discharge valve (2) and the gas outlet valve (4), and transport the catalyst particles to the fluidized attrition reactor (6) through the fluidizing gas in the carrier gas pipeline (3) and the fast carrier gas pipeline (5), wherein the ratio of the superficial gas velocity of the carrier gas pipeline (3) to the fast carrier gas pipeline (5) is 1:1.5-5; S2: After the catalyst particles collide and wear in the catalyst feed pipe (10), they rush into the bottom of the fluidized attrition reactor (6) for further collision and wear. After two stages of collision and wear, the catalyst particles gradually accumulate at the bottom of the fluidized attrition reactor (6) to form a catalyst bed; S3: closing the gas outlet valve (4) to keep the gas velocity and flow rate of the fluidizing gas in the carrier gas pipeline (3) constant, thereby further fluidizing the catalyst; S4: opening the first auxiliary fluidizing pipeline (7) and the second auxiliary fluidizing pipeline (9), and under the joint action of multiple fluidizing gases in the auxiliary fluidizing pipelines and the catalyst feed pipe (10), ensuring uniform contact between the catalyst particles and the fluidizing gas, thereby ensuring uniform wear of the catalyst particles; S5: After the abrasion is completed, the outlet valve (4) is opened, and the gas velocity of the fluidizing gas in the first auxiliary fluidizing pipeline (7) and the second auxiliary fluidizing pipeline (9) is appropriately increased to be able to blow up the catalyst particles, and the catalyst particles in the fluidized abrasion reactor (6) are quickly transported into the catalyst grading system for grading, so as to obtain catalyst particles of different particle size ranges.

2. A catalyst fluidized attrition classification method according to claim 1, characterized in that: The ratio of the diameter to the vertical height of the fluidized attrition reactor (6) in the device is 1:2-5.

3. A catalyst fluidized attrition classification method according to claim 2, characterized in that: The bottom of the inverted cone section of the fluidized abrasion reactor (6) in the device is a secondary collision abrasion zone (8), the vertical cross section of the secondary collision abrasion zone (8) is in the shape of an elliptical arc, and the ratio of the major axis to the minor axis of the elliptical arc is 1 to 3:

1.

4. A catalyst fluidized attrition classification method according to claim 2, characterized in that: In the device, the first auxiliary fluidizing pipeline (7) and the second auxiliary fluidizing pipeline (9) are located at 1 / 3 to 2 / 3 of the vertical height of the inverted cone section at the bottom of the fluidized attrition reactor (6), and the angle between the first auxiliary fluidizing pipeline (7) and the second auxiliary fluidizing pipeline (9) and the side wall of the inverted cone section at the bottom of the fluidized attrition reactor (6) is 60 to 90 degrees.

5. A catalyst fluidized attrition classification method according to claim 2, characterized in that: The total number of the first auxiliary fluidizing pipelines (7) and the second auxiliary fluidizing pipelines (9) in the device is 2 to 12.

6. A catalyst fluidized attrition classification method according to claim 1, characterized in that: The catalyst feed pipe (10) in the device is L-shaped, and the bent section of the catalyst feed pipe (10) is a primary collision wear zone (11).

7. A catalyst fluidized attrition classification method according to claim 6, characterized in that: The primary collision and wear zone (11) in the device is curved in an arc shape, and the vertical cross section of the primary collision and wear zone (11) is in the shape of an involute, the base circle radius of the involute is 1 to 2 times the radius of the catalyst feed pipe (10), and the extension angle of the involute is 70 to 90 degrees.

8. A catalyst fluidized attrition classification method according to claim 1, characterized in that: The catalyst classification system in the device comprises a primary cyclone separator (13) and a secondary cyclone separator (14); the inlet end of the primary cyclone separator (13) is connected to a catalyst delivery pipe (12), and is connected to the top of a fluidized attrition reactor (6) through the catalyst delivery pipe (12); the inlet end of the secondary cyclone separator (14) is connected to the outlet end of the primary cyclone separator (13), and the outlet end of the secondary cyclone separator (14) is connected to an exhaust pipeline (15).

9. A catalyst fluidized attrition classification method according to claim 8, characterized in that: The first-stage cyclone separator (13) obtains catalyst particles with a particle size range of 30 to 150 μm, the second-stage cyclone separator (14) obtains catalyst particles with a particle size range of no more than 45 μm, and the particle size of fine powder discharged from the exhaust pipeline (15) is no more than 10 μm.

10. A catalyst fluidized attrition classification method according to claim 1, characterized in that: The fluidizing gas is at least one of nitrogen, air and water vapor, and the gas temperature is 50-1000°C.

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