A system for recycling a silicon-aluminum catalyst

Abstract

The application provides a system for recycling silicon-aluminum catalyst, which comprises a waste liquid pool, a settling tank, a filter and a water evaporator connected in sequence; the bottom of the filter is connected with a fluidized bed; the top of the water evaporator is connected with a water condenser and a recovered water storage tank, the bottom of the water evaporator is connected with a second air heater, the second air heater is connected with the fluidized bed, and the recovered water storage tank is connected with the top of the filter. The system can recycle cyclohexanol and silicon-aluminum catalyst in catalyst waste liquid through settling, filtering, water evaporation and fluidized bed evaporation, so that the amount of silicon-aluminum catalyst used is reduced, the production cost is lowered, and the profit of the enterprise is increased; meanwhile, the discharge of catalyst waste liquid is controlled, and the environment is protected.

Description

Technical Field

[0001] This invention belongs to the field of catalyst recovery technology and relates to a system for recovering silicon-aluminum catalysts. Background Technology

[0002] The production of cyclohexanone typically uses a silica-alumina catalyst, but a portion of this catalyst is lost during the activation and alkaline washing process, requiring periodic replenishment and causing significant economic losses to the company. Additionally, some cyclohexanol is lost, resulting in material loss.

[0003] Currently, lost catalysts are typically recovered by filtration using plate filters or by purification using fluidized beds, but the catalyst recovery efficiency is low. Utility Model Content

[0004] The purpose of this invention is to provide a system for recovering silicon-aluminum catalysts to solve the problem of low recovery efficiency in existing methods.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a system for recovering silicon-aluminum catalysts, comprising a waste liquid tank, a settling tank, a filter, and a water evaporator connected in sequence; the bottom of the filter is connected to a fluidized bed; the top of the water evaporator is connected to a recovery water storage tank via a water condenser, and the bottom of the water evaporator is connected to a second air heater, which is connected to the fluidized bed; the recovery water storage tank is connected to the top of the filter.

[0007] Preferably, a cyclohexanol buffer tank is provided between the filter and the water evaporator.

[0008] Preferably, the cyclohexanol buffer tank is also connected to the waste liquid pool.

[0009] Preferably, the top of the fluidized bed is also connected to a first air heater, and the first air heater is connected to a second air heater and the recycled water storage tank.

[0010] Preferably, the bottom of the water evaporator is also connected to steam, and the condensate generated by the steam is connected to the second air heater.

[0011] Preferably, the system also includes a backup filter, which is connected in parallel with the filter and is connected to the settling tank, the recycled water storage tank, and the water evaporator.

[0012] This utility model has the following beneficial effects:

[0013] This application recovers cyclohexanol and silicon-aluminum catalyst from catalyst waste liquid through sedimentation, filtration, water evaporation, and fluidized bed evaporation, respectively, thereby reducing the amount of silicon-aluminum catalyst used, lowering production costs, and bringing profits to enterprises; at the same time, it also controls the discharge of catalyst waste liquid and protects the environment. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system for recovering silicon-aluminum catalysts provided in the embodiments of this application;

[0015] Symbolic representation:

[0016] 1-Waste liquid tank, 2-Settling tank, 3-Filter, 4-Water evaporator, 5-Fluidized bed, 6-Water condenser, 7-Recycled water storage tank, 8-Second air heater, 9-Cyclohexanol buffer tank, 10-First air heater, 11-Spare filter. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] This application provides a system for recovering silicon-aluminum catalysts. The system includes a waste liquid tank 1, a settling tank 2, a filter 3, and a water evaporator 4, which are connected in sequence, as shown in the attached diagram. Figure 1 As shown, waste liquid pool 1 is a component for storing waste catalyst waste liquid.

[0019] To ensure efficient collection of catalyst particles and subsequent processes, waste liquid tank 1 is connected to settling tank 2. Settling tank 2 is used to settle the catalyst in the waste liquid. The clear liquid after settling is discharged, while the turbid liquid is pumped into filter 3 via a screw pump. In filter 3, the turbid liquid is filtered by its own gravity and pressure difference, trapping catalyst particles and producing a cyclohexanol aqueous solution and a solid catalyst. The cyclohexanol aqueous solution produced by filter 3 enters water evaporator 4. In this embodiment, filter 3 is a plate and frame filter to facilitate solid-liquid separation.

[0020] In the water evaporator 4, a cyclohexanol aqueous solution is heated and evaporated at 145°C, generating water vapor at the top and cyclohexanol at the bottom, which is then recovered and reused. Since the top of the water evaporator 4 is connected to the recycled water storage tank 7 via a water condenser 6, the generated water vapor is condensed by the water condenser 6 and then enters the recycled water storage tank 7. In this embodiment, the water evaporator 4 is equipped with random packing material, which better prevents particle aggregation and operational accidents.

[0021] To heat the water evaporator 4, steam is connected to the bottom of the water evaporator 4. The water evaporator 4 is heated by the steam, and the condensate produced after heating is discharged into the second air heater 8 so that it can be used as hot water to heat the second air heater 8, thereby realizing heat recovery.

[0022] Furthermore, a cyclohexanol buffer tank 9 is provided between the filter 3 and the water evaporator 4 to buffer the cyclohexanol aqueous solution produced by the filter 3 and to allow some of the catalyst to settle into the cyclohexanol buffer tank 9. In addition, the cyclohexanol buffer tank 9 is also connected to the waste liquid tank 1 to facilitate the re-sedimentation and filtration of the catalyst settled in the cyclohexanol buffer tank 9.

[0023] The recycled water storage tank 7 is also connected to the top of the filter 3. Water stored in the recycled water storage tank 7 flows back to the top of the filter 3 to backwash the filtered catalyst, and then is discharged into the fluidized bed 5 through the bottom of the filter 3. In the fluidized bed 5, hot air generated by the second air heater 8 heats the catalyst in the fluidized bed 5 to evaporate moisture and concentrate the catalyst. After passing inspection, the catalyst directly enters the catalyst regeneration system.

[0024] In addition, the top of the fluidized bed 5 is connected to a first air heater 10, and the first air heater 10 is connected to a second air heater 8 and a recycled water storage tank 7. After the hot air generated by the second air heater 8 heats the catalyst in the fluidized bed 5, the evaporated water vapor overflows from the top of the fluidized bed 5 and enters the first air heater 10 for condensation. Part of the condensed water enters the recycled water storage tank 7 for reuse, and the other part is used as hot water return from the second air heater 8.

[0025] To achieve uninterrupted filtration of turbid liquid, the system provided in this application embodiment also includes a backup filter 11. The backup filter 11 is connected in parallel with the filter 3, and is used in a one-on-one configuration, replacing the filter 3 based on the internal pressure difference between the backup filter 11 and the filter 3. Both the backup filter 11 and the filter 3 are connected to the settling tank 2, the recycled water storage tank 7, and the water evaporator 4, respectively.

[0026] The workflow of the system for recovering silicon-aluminum catalysts provided in this application embodiment is as follows:

[0027] The catalyst waste liquid in waste liquid tank 1 enters settling tank 2. After settling in settling tank 2, the turbid liquid is pumped into filter 3 by a screw pump. Under its own gravity, the turbid liquid is filtered by pressure difference, trapping catalyst particles and producing cyclohexanol aqueous solution and solid catalyst. The cyclohexanol aqueous solution is discharged into water evaporator 4, where it is heated and evaporated at 145°C. Water vapor is generated at the top, and cyclohexanol is generated at the bottom. The generated water vapor is condensed by water condenser 6 and enters recycled water storage tank 7. The water stored in recycled water storage tank 7 is returned to the top of filter 3 to backwash the filtered catalyst, and then discharged into fluidized bed 5 through the bottom of filter 3. Hot air generated by second air heater 8 heats the catalyst in fluidized bed 5 to evaporate water and concentrate the catalyst. After passing inspection, the catalyst directly enters the catalyst regeneration system.

[0028] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A system for recovering silicon-aluminum catalysts, characterized in that, It includes a waste liquid tank (1), a settling tank (2), a filter (3) and a water evaporator (4) connected in sequence; the bottom of the filter (3) is connected to a fluidized bed (5); the top of the water evaporator (4) is connected to a recycled water storage tank (7) through a water condenser (6), and the bottom is connected to a second air heater (8), and the second air heater (8) is connected to the fluidized bed (5), and the recycled water storage tank (7) is connected to the top of the filter (3).

2. The system for recovering silicon-aluminum catalysts according to claim 1, characterized in that, A cyclohexanol buffer tank (9) is provided between the filter (3) and the water evaporator (4).

3. The system for recovering silicon-aluminum catalysts according to claim 2, characterized in that, The cyclohexanol buffer tank (9) is also connected to the waste liquid pool (1).

4. The system for recovering silicon-aluminum catalysts according to claim 1, characterized in that, The top of the fluidized bed (5) is also connected to the first air heater (10), and the first air heater (10) is connected to the second air heater (8) and the recycled water storage tank (7).

5. The system for recovering silicon-aluminum catalysts according to claim 1, characterized in that, The bottom of the water evaporator (4) is also connected to steam, and the condensate generated by the steam is connected to the second air heater (8).

6. The system for recovering silicon-aluminum catalysts according to any one of claims 1-5, characterized in that, It also includes a backup filter (11), which is connected in parallel with the filter (3) and is connected to the settling tank (2), the recycled water storage tank (7) and the water evaporator (4).

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