Dry process for separating white clay catalyst fines

Abstract

The application discloses a dry separation device for white powder of full clay catalyst, which comprises a rotary flash dryer, a first cyclone separator, a second cyclone separator and a bag-type dust collector connected in sequence. The application also discloses a dry separation method for white powder of full clay catalyst, which comprises the following steps: heating, scattering and fluidizing the full clay catalyst filter cake, and separating fine-particle white powder in the full clay catalyst filter cake through two-stage cyclone separation, so that the use standard of the full clay catalyst is reached. The method does not discharge and treat waste water, greatly reduces the investment and energy consumption of equipment, and reduces the production cost of the full clay catalyst.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil refining catalyst production, and particularly relates to a dry separation device for white powder of full-clay catalyst, and the present application also relates to a method for separating catalysts using the above device. BACKGROUND

[0002] Full-clay catalysts have high activity index, strong resistance to heavy metals, good hydrothermal stability, and pore distribution meeting the requirements of residue cracking, and therefore have wide application in the catalytic cracking industry. With the continuous progress of oil refining technology in China, the market demand is increasing, and the production capacity of catalyst manufacturers is continuously expanding. Full-clay catalysts used in the refining industry generally require a particle size of not less than 40 μm, and during the production of full-clay, about 30% of the fine powder produced is less than 40 μm, which is referred to as "white powder" and needs to be separated before being used as a catalyst for refining production.

[0003] Currently, the main method for separating catalyst white powder is as follows: after the full-clay catalyst is synthesized, it is first crystallized in a crystallization kettle, and then subjected to liquid-solid separation in a plate and frame filter, the filter cake is then subjected to beating in a beater tank, the full-clay catalyst slurry after beating is subjected to separation of white powder in a hydrocyclone, and the large-particle full-clay catalyst material after separation is subjected to drying treatment in a flash dryer, and the separated white powder and wastewater are subjected to subsequent wastewater treatment. This separation method mainly has the following shortcomings:

[0004] (1) The method of using a hydrocyclone for white powder separation requires a large amount of water for beating the full-clay catalyst filter cake, which on the one hand increases the consumption of fresh water, causing waste of water resources, and on the other hand, the beater tank consumes a large amount of electricity, and the feed of the hydrocyclone requires a feed pump, also increasing the electricity consumption of the system, thus increasing the production cost of full-clay catalysts;

[0005] (2) The use of a hydrocyclone for white powder separation produces a large amount of wastewater, as the white powder is suspended in the liquid, increasing the difficulty of subsequent wastewater treatment, and with the continuous improvement of the production capacity of full-clay catalysts, the subsequent wastewater treatment system needs to be modified, which not only increases the investment in equipment, but also consumes a large amount of energy during the wastewater treatment process, greatly increasing the production cost of full-clay catalysts.

[0006] Therefore, it is an urgent need in the field to adopt a reasonable, simple and efficient white powder separation method. SUMMARY

[0007] The present application aims to provide a dry separation method of full clay catalyst white powder, which does not need to use water, reduces water consumption, does not need to carry out wastewater treatment, and reduces the production cost of full clay catalyst.

[0008] Another object of the present application is to provide a separation device used in the above dry separation method.

[0009] The technical scheme adopted by the present application is a dry separation device of full clay catalyst white powder, which comprises a rotary flash dryer, a first cyclone separator, a second cyclone separator and a bag-type dust collector connected in sequence.

[0010] The present application is also characterized in that:

[0011] The lower part of the rotary flash dryer is connected with an electric heater, and the other end of the electric heater is connected with a blower, which is in communication with external air.

[0012] The feed inlet of the rotary flash dryer is connected with a rotary flash drying screw conveyor, and the bottom of the rotary flash dryer is provided with a scatterer.

[0013] The bottom of the first cyclone separator and the second cyclone separator is respectively provided with a first rotary unloading valve and a second rotary unloading valve.

[0014] The bottom of the bag-type dust collector is provided with a bag-type rotary unloading valve, and the top of the bag-type dust collector is connected with an induced draft fan.

[0015] Another technical scheme adopted by the present application is a dry separation method of full clay catalyst white powder, which heats, scatters and fluidizes the full clay catalyst filter cake in the rotary flash dryer, then separates the dispersed catalyst particles through a first cyclone dust collector and a second cyclone dust collector in sequence, obtains fine particle white powder at the top of the second cyclone dust collector, and finally separates the fine particle white powder in a bag-type dust collector to obtain full clay catalyst white powder.

[0016] The present application is also characterized in that:

[0017] The dry separation method of full clay catalyst white powder is implemented according to the following steps:

[0018] Step 1, start the blower and the electric heater, so that hot air enters the bottom of the rotary flash dryer tangentially;

[0019] Step 2, the full clay catalyst filter cake is conveyed to the rotary flash dryer by the rotary flash drying screw conveyor, and under the action of hot air and the scatterer, the filter cake is heated, scattered, fluidized, and then rises to the top of the rotary flash dryer;

[0020] Step 3: The full clay catalyst after drying and dispersion in step 2 is discharged from the top of the flash dryer into a primary cyclone dust collector, and is preliminarily separated therein, most of the large-particle materials being separated, and the separated large-particle materials being discharged from the bottom of the primary cyclone dust collector;

[0021] Step 4: The fine-particle catalyst after separation in step 3 enters a secondary cyclone dust collector from the top of the primary cyclone dust collector, and is further separated therein, the separated full clay catalyst large-particle materials being discharged from the bottom of the secondary cyclone dust collector, and the fine-particle white powder rising with the airflow to the top of the secondary cyclone dust collector;

[0022] Step 5: The white powder of the full clay catalyst after separation in step 4 enters a bag dust collector, where gas-solid separation is performed, the separated white powder being discharged from the bottom of the bag dust collector, and the dry tail gas after purification being discharged by an induced draft fan to a subsequent treatment system.

[0023] The temperature of the hot air in step 1 is 150-180℃.

[0024] The hot air flow in the flash dryer in step 2 is 800-1200kg / h.

[0025] The dust removal critical particle diameter of the primary cyclone dust collector is 80 microns, and the dust removal critical particle diameter of the secondary cyclone dust collector is 40 microns.

[0026] The beneficial effects of the present application are:

[0027] (1) The method of the present application can separate the white powder and catalyst large particles of different particle sizes by using dry separation technology, without additional consumption of fresh water and generation of wastewater, thereby saving a large amount of water resources; the method of the present application has no wastewater discharge and treatment, greatly reduces the investment and energy consumption of the equipment, and reduces the production cost of the full clay catalyst;

[0028] (2) The method of the present application uses a flash dryer + two-stage cyclone separation system to replace the original beating tank + liquid cyclone separation + flash dryer + wastewater treatment system, shortens the process flow of the full clay catalyst production process, uses a two-stage cyclone dust collector in series to achieve the separation effect of the existing liquid cyclone separator, and is simpler to operate, with greatly reduced equipment investment, land occupation and energy consumption;

[0029] (3) The method of the present application has no wastewater discharge, and the dry tail gas after dust removal and purification is directly discharged to the existing washing and dust removal system, greatly reducing the discharge of wastewater, and having important significance for environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Fig. 1 is a structural schematic diagram of the dry separation device of the present application.

[0031] In the diagram, 1. Blower, 2. Electric heater, 3. Rotary flash dryer, 4. Rotary flash dryer screw conveyor, 5. Primary cyclone separator, 6. Secondary cyclone separator, 7. Bag filter, 8. Exhaust fan, 9. Primary rotary discharge valve, 10. Secondary rotary discharge valve, 11. Bag rotary discharge valve. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0033] This invention discloses a dry separation device for white powder from all-clay catalyst, such as... Figure 1 As shown, the system includes a cyclone dryer 3, a primary cyclone separator 5, a secondary cyclone separator 6, and a bag filter 7 connected in sequence. An electric heater 2 is connected to the lower part of the cyclone dryer 3, and a blower 1 is connected to the other end of the electric heater 2. The blower 1 is connected to the outside air, and the outside air enters the electric heater 2 under the action of the blower 1, is heated to a certain temperature, and then enters tangentially from the lower part of the cyclone dryer 3. A cyclone drying screw conveyor 4 is connected to the feed inlet of the cyclone dryer 3, and the kaolin material to be separated enters the cyclone dryer 3 through the cyclone drying screw conveyor 4. A dispersant is installed at the bottom of the cyclone dryer 3. The bottom of the primary cyclone separator 5 and the secondary cyclone separator 6 are respectively equipped with a primary rotary discharge valve 9 and a secondary rotary discharge valve 10; the bottom of the bag filter 7 is equipped with a bag rotary discharge valve 11; the top of the bag filter 7 is connected to an induced draft fan 8, which discharges the purified and dried exhaust gas in the bag filter 7 to the subsequent treatment system.

[0034] This invention discloses a dry separation method for white powder from all-clay catalyst, which is implemented according to the following steps:

[0035] Step 1: Start the blower 1 and the electric heater 2 to ensure that the temperature of the hot air that passes through the electric heater 2 and reaches the bottom of the flash dryer 3 reaches 150℃~180℃. The hot air enters tangentially from the bottom of the flash dryer 3.

[0036] The heat source during the drying process can be hot air or hot flue gas. If hot air is used as the heat source, the heater can be an electric heater or a steam-heated finned tube heat exchanger. If factory flue gas is used as the heat source, the hot flue gas can directly enter the cyclone flash dryer 3 without the need for a blower 1 and an electric heater 2.

[0037] Step 2, the full clay catalyst filter cake with a moisture content of about 40% at 30-40℃ from the upstream plate and frame filter is fed into the spin flash dryer screw conveyor 4, and then is conveyed to the spin flash dryer 3, and falls into the bottom of the spin flash dryer 3, and the disperser in the bottom rotates at high speed to disperse the full clay catalyst filter cake; under the action of the air blower 1 and the electric heater 2, hot air or hot flue gas at 150-180℃ enters the bottom of the spin flash dryer 3 tangentially, the full clay catalyst material is fluidized, and rises spirally to the top of the spin flash dryer with the hot air or hot flue gas, in the process, the moisture in the full clay catalyst is continuously evaporated, and the full clay catalyst with a moisture content of about 4% is obtained at the outlet of the spin flash dryer 3;

[0038] Step 3, the full clay catalyst after drying and dispersion in step 2, the drying tail gas and the water evaporated in the evaporation process are discharged from the top of the spin flash dryer 3 to the primary cyclone dust collector 5, in the primary cyclone dust collector 5, the full clay catalyst is preliminarily separated, and most of the large particle materials are separated, and the separated large particle materials are discharged from the primary rotary discharge valve 9 to the subsequent system;

[0039] Step 4, the drying tail gas and part of the full clay catalyst particles after separation in the primary cyclone dust collector 5 are then fed into the secondary cyclone dust collector 6, in the secondary cyclone dust collector 6, the full clay catalyst large particle material is further separated, the separated full clay catalyst large particle material is discharged from the secondary rotary discharge valve 10 to the subsequent system, and the fine particle white powder rises to the top of the secondary cyclone dust collector 6 with the airflow;

[0040] Step 5, the drying tail gas and the full clay catalyst white powder after separation in the secondary cyclone dust collector 6 are fed into the bag dust collector 7, and gas-solid separation is carried out here, the white powder generated by separation is discharged from the bag rotary discharge valve 11, and the purified drying tail gas is discharged to the subsequent treatment system through the induced draft fan 8.

[0041] Example 1

[0042] The embodiment uses an electric heater to heat air to 150-160°C and pass into the rotary flash dryer 3. The temperature of the full clay catalyst filter cake is 30°C and the moisture content is 41-43%. The filter cake is transported to the rotary flash dryer 3 by the rotary flash drying screw conveyor 4. The wet material directly contacts and exchanges heat with the hot air. The hot air flow is 800-1000 kg / h. The dried material is taken out of the rotary flash dryer 3 by the drying tail gas. The temperature of the drying tail gas is 120-130°C. Then the drying tail gas enters the primary cyclone separator 5 to perform the initial gas-solid separation. The primary cyclone separator 5 is designed according to a critical diameter of 80 microns to separate most of the particles above 80 microns. Then the drying tail gas enters the secondary cyclone separator 6 which is designed according to a critical diameter of 40 microns to further separate the particles above 40 microns. The separated drying tail gas and part of the dust enter the bag-type dust collector 7 to remove the white powder. After two-stage separation, the solid particles above 40 microns account for 87.8% and the solid particles below 40 microns account for 12.2%. The yield of the required product, the solid particles above 40 microns, is 93.6%. The pressure drop of each cyclone separator is 300-500 Pa. It has been verified that, after the full clay catalyst is separated by the hydrocyclone, the solid particles above 40 microns account for 85-90%. The dry separation method of the present application can also achieve similar separation effect.

[0043] Example 2

[0044] In this embodiment, an electric heater is used. The temperature of the hot air passing through the electric heater 2 and reaching the bottom of the rotary flash dryer 3 is 160-180°C. The hot air flow is 1000-1200 kg / h. The rest is the same as in Example 1. The yield of the separated solid particles above 40 microns is 94.5%.

[0045] Example 3

[0046] In this embodiment, hot flue gas is directly introduced into the rotary flash dryer 3. The temperature of the hot flue gas is 170-180°C. The hot air flow is 1000-1200 kg / h. The rest is the same as in Example 1. The yield of the separated solid particles above 40 microns is 92.4%.

Claims

1. A dry separation device for white powder from all-clay catalyst, characterized in that, It includes a cyclone flash dryer (3), a primary cyclone separator (5), a secondary cyclone separator (6), and a bag filter (7) connected in sequence. The lower part of the flash dryer (3) is connected to an electric heater (2), and the other end of the electric heater (2) is connected to a blower (1), which is connected to the outside air. The feed inlet of the flash dryer (3) is connected to a flash dryer screw conveyor (4), and a dispersant is provided at the bottom of the flash dryer (3). The bottom of the primary cyclone separator (5) and the secondary cyclone separator (6) are respectively provided with a primary rotary discharge valve (9) and a secondary rotary discharge valve (10). The bottom of the bag filter (7) is provided with a bag rotary unloading valve (11), and the top of the bag filter (7) is connected to an induced draft fan (8).

2. A dry separation method for white powder from all-natural clay catalyst, characterized in that, The dry separation apparatus as described in claim 1 is implemented specifically according to the following steps: Step 1: Start the blower (1) and electric heater (2) to allow hot air to enter the bottom of the cyclone dryer (3) tangentially; Step 2: The whole clay catalyst filter cake is conveyed to the flash dryer (3) by the flash dryer screw conveyor (4). Under the action of hot air and the disperser, the filter cake is heated, dispersed and fluidized, and then rises to the top of the flash dryer (3). Step 3: The whole clay catalyst, after being dried and dispersed in step 2, is discharged from the top of the flash dryer (3) into the first-stage cyclone separator (5), where it is initially separated. Most of the large particles are separated and discharged from the bottom of the first-stage cyclone separator (5). Step 4: The finer particles of catalyst separated in step 3 enter the secondary cyclone separator (6) from the top of the primary cyclone separator (5) and are further separated there. The large particles of the separated kaolin catalyst are discharged through the bottom of the secondary cyclone separator (6), while the fine particles of white powder rise to the top of the secondary cyclone separator (6) with the airflow. Step 5: The white powder of the kaolin catalyst after separation in step 4 enters the bag filter (7) for gas-solid separation. The white powder produced by separation is discharged from the bottom of the bag filter (7). The purified and dried tail gas is discharged to the subsequent treatment system through the induced draft fan (8). The temperature of the hot air in step 1 is 150℃~180℃; The hot air flow rate in the cyclone flash dryer (3) in step 2 is 800 kg / h ~ 1200 kg / h; The critical particle size for dust removal in the primary cyclone separator (5) is 80 micrometers, and the critical particle size for dust removal in the secondary cyclone separator (6) is 40 micrometers.

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