Treatment process and device for etbe catalyst

Abstract

The present application belongs to the technical field of catalyst treatment, and particularly relates to a treatment process and a treatment device for ETBE catalyst. The treatment process is as follows: firstly, the catalyst is installed in a reactor and / or a catalytic rectification tower; then, ETBE is introduced into the reactor and / or the catalytic rectification tower; after the ETBE passes through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic rectification tower, the ETBE is discharged into a material tank, and is subjected to sedimentation and layering in the material tank; the water in the lower layer is discharged by a water discharge device, and the ETBE in the upper layer is returned to the reactor and / or the catalytic rectification tower for recycling; when the water content in the ETBE discharged from the reactor and / or the catalytic rectification tower is not more than 10%, the introduction of the ETBE is stopped, and the treatment of the catalyst is completed. The process flow of the present application is simple, the treatment process is short in time, the dehydration effect of the catalyst is good, a large amount of energy consumption is saved, and the amount of unqualified products in the initial stage of application of the dehydrated catalyst is small.

Description

Technical Field

[0001] This invention belongs to the field of catalyst treatment technology, specifically relating to a treatment process and apparatus for ETBE catalyst. Background Technology

[0002] In chemical production, ethyl tert-butyl ether (ETBE) is produced by reacting mixed C4 atoms with ethanol, typically using a sulfonic acid-type ion exchange resin catalyst. Fresh catalysts usually contain about 50% water. If used directly in ETBE production, the water in the catalyst will react with isobutylene in the mixed C4 atoms to form tert-butanol, significantly reducing the purity of the ETBE product. Therefore, the water in the catalyst must be removed before use in the etherification reaction. Currently, the catalyst is usually dehydrated by soaking it in ethanol and replacing the water. However, this process generates a large amount of ethanol-water solution, and recovering the ethanol through distillation incurs energy costs. Simultaneously, the catalyst contains a significant amount of residual ethanol. During the initial startup phase, a large amount of excess ethanol enters the distillation column. Because the ethanol azeotropic composition in the C4-ethanol azeotrope is particularly low, exceeding the maximum concentration of the azeotrope, it cannot be distilled off from the top of the column and instead enters the bottom. This results in a significant excess of ethanol in the ETBE product at the bottom of the column, leading to a large quantity of substandard product in the initial startup phase. In addition, since ethanol and water form an azeotrope, the ethanol recovered through distillation contains about 5% water. Therefore, the catalyst dehydration process will produce a large amount of aqueous ethanol. This aqueous ethanol cannot be used in ETBE production because the water in it will react with isobutylene in the mixed C4 to produce tert-butanol, resulting in the tert-butanol content in the ETBE product exceeding the standard.

[0003] Patent CN103127961 discloses a catalyst swelling and soaking process for an MTBE industrial reactor, including feeding, soaking, and dehydration processes. A centrifugal pump is used to introduce post-ether mixed C4 to a reactor containing new catalyst, increasing the reactor pressure, closing the reactor inlet and outlet, and allowing the mixed C4 to settle before being drawn back to a settling tank under its own pressure. The material in the settling tank is then allowed to settle and dehydrate before being sent out. However, mixed C4 is a non-polar substance with weak adsorption capacity, making it difficult to adsorb into the deep pores of the catalyst particles and remove moisture from these pores. This process relies on prolonged and repeated catalyst soaking, which is time-consuming and uses a large amount of C4 material. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a processing technology for ETBE catalyst, which has a simple process flow, short processing time, good dehydration effect of catalyst, no aqueous ethanol is generated during the dehydration process, saving a lot of energy consumption, and the amount of unqualified products in the initial stage of application of the catalyst after dehydration is small; the present invention also provides a processing device.

[0005] The ETBE catalyst processing technology of the present invention includes the following steps:

[0006] First, the catalyst is installed in the reactor and / or catalytic distillation column. Then, ETBE is introduced into the reactor and / or catalytic distillation column. After passing through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column, the ETBE is discharged into a material tank. In the material tank, sedimentation and stratification take place. The water in the lower layer is discharged from the device, and the ETBE in the upper layer is returned to the reactor and / or catalytic distillation column for recycling. When the water content in the ETBE discharged from the reactor and / or catalytic distillation column is no more than 10%, the introduction of ETBE is stopped, and the treatment of the catalyst is completed.

[0007] In this invention, the catalyst is a sulfonic acid type ion exchange resin catalyst used in the ETBE reaction, with a water content of 10-80 wt%.

[0008] In this invention, the volume hourly space velocity (VHSV) of the ETBE through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column is 1-5 h⁻¹. -1 The air velocity has a significant impact on the dehydration effect; if the air velocity is too high or too low, the dehydration effect of the catalyst will not be ideal.

[0009] In this invention, the temperature of the ETBE passing through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column is 10-60°C, and the pressure is preferably atmospheric pressure.

[0010] In this invention, the mass content of ETBE is 90-100%, preferably 95-100%.

[0011] In this invention, the reactor can be a fixed-bed reactor that can control the reaction temperature, such as a mixed-phase bed reactor, an adiabatic fixed-bed reactor, a tubular fixed-bed reactor, or an expanded-bed reactor.

[0012] In this invention, the catalyst filling form in the catalytic distillation column can be bulk or packed, such as bundled or modular.

[0013] In this invention, ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through the reflux feed port or the ethanol feed port.

[0014] When ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through the ethanol feed inlet, it can be introduced into the catalyst bed of the reaction section of the catalytic distillation column through one ethanol feed inlet, or it can be introduced into the catalyst bed of the reaction section of the catalytic distillation column through two or more ethanol feed inlets in stages; preferably, ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through two or more ethanol feed inlets in stages, which results in better dehydration effect.

[0015] The ETBE catalyst processing device of the present invention includes a reactor, a catalytic distillation column and a material tank. The reactor and the catalytic distillation column are equipped with catalysts. The inlets of the reactor and the catalytic distillation column are respectively connected to an ETBE addition pipe and a material tank. The outlets of the reactor and the catalytic distillation column are connected to the inlet of the material tank.

[0016] Preferably, the feed inlets of the reactor and the catalytic distillation column are connected to the ETBE addition pipe and the material tank, respectively, after passing through a reflux pump.

[0017] Preferably, a dehydration bag is provided at the bottom of the material tank, and the dehydration bag is connected to a drain pipe.

[0018] Preferably, the material tank is an existing top reflux tank of the catalytic distillation column.

[0019] Preferably, the feed inlet of the catalytic distillation column is either the reflux feed inlet of the catalytic distillation column or at least one of the make-up ethanol feed inlet of the catalytic distillation column.

[0020] More preferably, when the feed inlet of the catalytic distillation column is one ethanol replenishment inlet, the ethanol replenishment inlet is located above the tray above the reaction section of the catalytic distillation column; when the feed inlet of the catalytic distillation column is two ethanol replenishment inlets, the two ethanol replenishment inlets are located above the tray above the reaction section of the catalytic distillation column and above the tray at the halfway point of the reaction section of the catalytic distillation column, respectively.

[0021] The ETBE catalyst processed in this invention is a sulfonic acid-type ion exchange resin catalyst. The catalyst particles contain numerous pores to provide a large active surface area for the ETBE synthesis reaction. Freshly manufactured catalysts typically contain a certain amount of moisture. Furthermore, catalysts that have undergone moisture removal may accidentally regain moisture during use. This moisture exists not only between catalyst particles and on the surface of the particles but also largely adsorbed within the pores of the catalyst particles. Compared to using C4 as a dehydrating agent to remove moisture from the ETBE catalyst, C4, being a non-polar substance, has weak adsorption capacity and struggles to adsorb deep into the pores of the catalyst particles, making it difficult to remove moisture from these deep pores. This invention uses ETBE as a dehydrating agent. Because ETBE is a polar substance, it effectively removes moisture from deep within the catalyst pores, resulting in a better dehydration effect. Additionally, ETBE is a liquid at atmospheric pressure, allowing for convenient dehydration operations. C4, being a gas at atmospheric pressure, cannot be dehydrated under atmospheric pressure, making the process inconvenient.

[0022] During catalyst dehydration, the principle of immiscibility between water and ETBE is utilized. ETBE and water separate into upper and lower layers through sedimentation in the material tank. The water is discharged from the dehydration device. Simultaneously, a reflux pump is used to send ETBE from the material tank into the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column. ETBE can be sent into the catalyst bed in the reaction section of the catalytic distillation column through the reflux inlet or the ethanol feed inlet. While one ethanol feed inlet can be used, it is preferable to use two or more ethanol feed inlets to feed ETBE into the catalyst bed in stages for better dehydration. When the catalytic distillation column has two ethanol feed inlets, one is typically located above the upper tray of the reaction section, and the other is located above any tray in the middle of the reaction section. When the water content in the ETBE discharged from the reactor and / or catalytic distillation column is not greater than 10%, the ETBE circulation should be stopped and the ETBE in the reactor and / or catalytic distillation column should be completely discharged.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] The ETBE catalyst treatment process of this invention uses ETBE to remove moisture from the catalyst. Compared with using ethanol as a dehydrating agent, it: does not produce aqueous ethanol; utilizes the principle that water and ETBE are immiscible, ETBE and water are separated into upper and lower layers through sedimentation, eliminating the need for distillation and saving significant energy; there is no residual ethanol in the catalyst at the initial stage of operation, and residual ETBE will not affect product purity, resulting in a small amount of substandard product; compared with using C4 as a dehydrating agent, ETBE continuously and circulates through the catalyst, eliminating the need for prolonged catalyst soaking, reducing time and material consumption; the dehydration process can be carried out at atmospheric pressure, making operation convenient; ETBE has a certain polarity, effectively removing moisture deep within the catalyst pores, resulting in good dehydration effect, reducing the tert-butanol content in the ETBE product at the initial stage of operation, shortening the time for product quality to reach the qualified standard, and significantly improving the economic efficiency of the plant. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the ETBE catalyst processing device of the present invention. Figure 1 ;

[0026] Figure 2 This is a schematic diagram of the ETBE catalyst processing device of the present invention. Figure 2 ;

[0027] Figure 3 This is a schematic diagram of the ETBE catalyst processing device of the present invention. Figure 3 ;

[0028] In the diagram: 1. Reactor; 2. Catalytic distillation column; 3. Reflux pump; 4. Material tank; 5. Dehydration bag; 6. Drain pipe; 7. ETBE addition pipe. Detailed Implementation

[0029] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto. Any changes made to the technical solutions of the present invention by those skilled in the art should fall within the scope of protection of the present invention.

[0030] Example 1

[0031] like Figure 1-3 As shown, an ETBE catalyst processing device includes a reactor 1, a catalytic distillation column 2, and a material tank 4. The reactor 1 and the catalytic distillation column 2 are equipped with catalysts. The inlets of the reactor 1 and the catalytic distillation column 2 are connected to the ETBE addition pipe 7 and the material tank 4 respectively via a reflux pump 3. The outlets of the reactor 1 and the catalytic distillation column 2 are connected to the inlet of the material tank 4. A dehydration bag 5 is provided at the bottom of the material tank 4, and the dehydration bag 5 is connected to a drain pipe 6. Valves are installed on each pipeline of the device as needed to control the flow of materials.

[0032] The reactor 1 can be a fixed-bed reactor with controllable reaction temperature, such as a mixed-phase bed reactor, an adiabatic fixed-bed reactor, or a tubular fixed-bed reactor, or an expanded-bed reactor. The type of reactor does not affect the operation and treatment effect of this device.

[0033] The catalyst in the catalytic distillation column 2 can be packed in bulk or in a packed manner, such as in bundles or modules. The catalyst packing method does not affect the operation and processing efficiency of this device.

[0034] The material tank 4 is the existing top reflux tank of the catalytic distillation column 2.

[0035] The feed inlet of the catalytic distillation column 2 is either the reflux feed inlet of the catalytic distillation column 2 or at least one of the ethanol replenishment feed inlet of the catalytic distillation column 2.

[0036] Figure 1 The feed inlet of the catalytic distillation column 2 is the reflux feed inlet of the catalytic distillation column 2. ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through the reflux feed inlet of the catalytic distillation column 2.

[0037] Figure 2 The feed inlet of the catalytic distillation column 2 is a supplementary ethanol feed inlet. This supplementary ethanol feed inlet is located above the tray above the reaction section of the catalytic distillation column 2. ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through this supplementary ethanol feed inlet.

[0038] Figure 3 The feed inlets of the catalytic distillation column 2 are two ethanol feed inlets. The two ethanol feed inlets are located above the tray above the reaction section of the catalytic distillation column 2 and above the tray at the halfway point of the reaction section of the catalytic distillation column 2, respectively. ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column in stages through the two ethanol feed inlets.

[0039] Example 2

[0040] The ETBE catalyst was dehydrated using the processing apparatus of Example 1, and the steps are as follows:

[0041] First, a sulfonic acid-type ion exchange resin catalyst (water content 54.2%) for the ETBE reaction was installed in the reactor. Then, ETBE (99% by mass) was passed through the catalyst bed in the reactor using a reflux pump at a volume hourly space velocity (VHSV) of 1.0 h⁻¹. -1The ETBE discharged from the reactor enters the material tank. The water in the ETBE is discharged from the dehydration device of the material tank. A reflux pump is used to send the ETBE in the material tank back into the reactor for recycling. After 20 hours, the water content in the ETBE discharged from the reactor is 5.2%. The ETBE supply is stopped, and the ETBE in the reactor is completely discharged, completing the dehydration treatment of the ETBE catalyst.

[0042] Analysis and calculation showed that the moisture content in the catalyst was reduced to 2.4%. When the catalyst was put into ETBE production, the quality of ETBE products reached 97% of the qualified standard within 12 hours.

[0043] Comparative Example 1

[0044] The ETBE catalyst was dehydrated using the processing apparatus of Example 1, and the steps are as follows:

[0045] Using a reflux pump, the etherified C4 produced after MTBE production is passed through the catalyst bed in the reactor. The reactor pressure is increased to 0.8 MPa, the reflux pump is stopped, and the reactor inlet and outlet are closed to maintain a high-pressure state. The reactor is allowed to stand for 9 hours. The reactor outlet is then opened, and the swollen and soaked C4 and water are drawn into a material tank under pressure. After standing for 4 hours, the water that has separated into layers is discharged from the dehydration tank. This process is repeated three times. The water content in the C4 discharged from the reactor is 5.1%. The C4 in the reactor is then completely discharged, completing the dehydration treatment of the ETBE catalyst. The remaining operations are the same as in Example 2.

[0046] Analysis and calculation showed that the moisture content in the catalyst was reduced to 4.9%. When the catalyst was put into ETBE production, the quality of ETBE products reached 97% of the qualified standard within 18 hours.

[0047] Example 3

[0048] The ETBE catalyst was dehydrated using the processing apparatus of Example 1, and the steps are as follows:

[0049] First, a sulfonic acid-type ion exchange resin catalyst (water content 50.3%) for the ETBE reaction was installed in the reactor and catalytic distillation column. Then, ETBE (99% by mass) was passed through the catalyst bed in the reactor and the catalyst bed in the reaction section of the catalytic distillation column using a reflux pump, with a volume hourly space velocity (VHSV) of 1.0 h⁻¹. -1 ETBE discharged from the reactor and catalytic distillation column enters the feed tank. Moisture in the ETBE is discharged from the dehydration device in the feed tank. A reflux pump then pumps the ETBE from the feed tank back into the reactor and catalytic distillation column for recycling. ETBE is fed into the catalyst bed (e.g., ethanol feed) in the reaction section of the catalytic distillation column through a makeup ethanol inlet. Figure 2As shown in the figure, the ethanol feed inlet is located above the tray above the reaction section of the catalytic distillation column. After 22 hours, the water content in the ETBE discharged from the reactor and catalytic distillation column drops to below 10%, and the ETBE supply is stopped. The ETBE in the reactor and catalytic distillation column is then completely discharged, thus completing the dehydration treatment of the ETBE catalyst.

[0050] Analysis and calculations showed that the residual water content in the catalyst in the reactor and catalytic distillation column was 1.37% and 1.45%, respectively. When the catalyst was added to ETBE production, the ETBE product quality reached 97% compliance within 10 hours.

[0051] Example 4

[0052] Using the same conditions as in Example 3, the difference is that ETBE is fed into the catalyst bed of the reaction section of the catalytic distillation column through two ethanol feed inlets. The two ethanol feed inlets are located above the tray at the top of the reaction section and above the tray at the halfway point of the reaction section, respectively (e.g., ...). Figure 3 (As shown). The water content of the catalyst residue in the reactor and catalytic distillation column was 1.01% and 1.14% by mass, respectively.

[0053] Example 5

[0054] The ETBE catalyst was dehydrated using the processing apparatus of Example 1, and the steps are as follows:

[0055] First, a sulfonic acid-type ion exchange resin catalyst (water content 40.9%) for the ETBE reaction was installed in the reactor and catalytic distillation column. Then, ETBE (95% by mass) was passed through the catalyst bed in the reactor and the catalyst bed in the reaction section of the catalytic distillation column, with a volume hourly space velocity (VHSV) of 3.0 h⁻¹. -1 ETBE is fed into the catalyst bed (e.g., in the reaction section of the catalytic distillation column) through the reflux feed inlet of the catalytic distillation column. Figure 1 (As shown). The remaining operations are the same as in Example 3.

[0056] After 21 hours, the water content in the ETBE discharged from the reactor and catalytic distillation column dropped to below 10%. Analysis and calculation showed that the water content of the catalyst residue in the reactor and catalytic distillation column was 2.28% and 2.39%, respectively.

[0057] Example 6

[0058] The ETBE catalyst was dehydrated using the processing apparatus of Example 1, and the steps are as follows:

[0059] First, a sulfonic acid-type ion exchange resin catalyst (water content 30.5%) for the ETBE reaction was installed in the reactor. Then, ETBE (99.5% by mass) was passed through the catalyst bed in the reactor using a reflux pump at a volume hourly space velocity (VHSV) of 5.0 h⁻¹. -1 The ETBE discharged from the reactor enters the material tank. The water in the ETBE is discharged from the dehydration device of the material tank. A reflux pump is used to send the ETBE in the material tank back into the reactor for recycling. After 19 hours, the water content in the ETBE discharged from the reactor drops below 10%, the ETBE supply is stopped, and the ETBE in the reactor is completely discharged, completing the dehydration treatment of the ETBE catalyst.

[0060] Analysis and calculations showed that the moisture content in the catalyst was reduced to 2.8%.

[0061] Comparative Example 2

[0062] The process operation is the same as in Example 3. The difference is that the volume hourly space velocity (VHSV) of ETBE in both the catalyst bed in the reactor and the catalyst bed in the reaction section of the catalytic distillation column is 0.5 h⁻¹. -1 .

[0063] After 30 hours, the water content in the ETBE discharged from the reactor and catalytic distillation column dropped to below 10%. Analysis and calculation showed that the water content of the catalyst residue in the reactor and catalytic distillation column was 5.69% and 6.17%, respectively.

[0064] Comparative Example 3

[0065] The process operation is the same as in Example 3. The difference is that the volume hourly space velocity (VHSV) of ETBE in both the catalyst bed in the reactor and the catalyst bed in the reaction section of the catalytic distillation column is 8 h⁻¹. -1 .

[0066] After 33 hours, the water content in the ETBE discharged from the reactor and catalytic distillation column dropped to below 10%. Analysis and calculation showed that the water content of the catalyst residue in the reactor and catalytic distillation column was 6.27% and 6.89%, respectively.

Claims

1. A process for processing ETBE catalyst, characterized in that: Includes the following steps: First, the catalyst is installed in the reactor and / or catalytic distillation column. Then, ETBE is introduced into the reactor and / or catalytic distillation column. After passing through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column, the ETBE is discharged into a material tank. In the material tank, sedimentation and stratification take place. The water in the lower layer is discharged from the device, and the ETBE in the upper layer is returned to the reactor and / or catalytic distillation column for recycling. When the water content in the ETBE discharged from the reactor and / or catalytic distillation column is no more than 10%, the introduction of ETBE is stopped, and the treatment of the catalyst is completed.

2. The processing method for the ETBE catalyst according to claim 1, characterized in that: The catalyst is a sulfonic acid type ion exchange resin catalyst used in the ETBE reaction, with a water content of 10-80 wt%.

3. The processing method for the ETBE catalyst according to claim 1, characterized in that: The volumetric space velocity of the ETBE through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column is 1-5 h⁻¹. -1 .

4. The processing method for the ETBE catalyst according to claim 1, characterized in that: The temperature of the ETBE as it passes through the catalyst bed in the reactor and / or the catalyst bed in the reaction section of the catalytic distillation column is 10-60°C, and the pressure is atmospheric pressure.

5. The processing method for the ETBE catalyst according to claim 1, characterized in that: ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through the reflux feed port or the ethanol feed port.

6. The processing method for the ETBE catalyst according to claim 5, characterized in that: When ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column through the ethanol feed inlet, ETBE is introduced into the catalyst bed of the reaction section of the catalytic distillation column in stages through two or more ethanol feed inlets.

7. The processing method for the ETBE catalyst according to claim 1, characterized in that: The processing device includes a reactor (1), a catalytic distillation column (2) and a material tank (4). The reactor (1) and the catalytic distillation column (2) are equipped with catalysts. The inlets of the reactor (1) and the catalytic distillation column (2) are connected to the ETBE addition pipe (7) and the material tank (4) respectively. The outlets of the reactor (1) and the catalytic distillation column (2) are connected to the inlet of the material tank (4). The feed inlets of the reactor (1) and the catalytic distillation column (2) are connected to the ETBE addition pipe (7) and the material tank (4) respectively via the reflux pump (3). The material tank (4) is the top reflux tank of the catalytic distillation column (2). A dehydration bag (5) is provided at the bottom of the material tank (4), and the dehydration bag (5) is connected to the drain pipe (6).

8. The processing method for the ETBE catalyst according to claim 7, characterized in that: The feed inlet of the catalytic distillation column (2) is either the reflux feed inlet of the catalytic distillation column (2) or the ethanol feed inlet of the catalytic distillation column (2).

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