Method for treating and recycling dimethyl ether carbonylation catalyst activator

Abstract

The invention belongs to the technical field of catalyst pretreatment, and particularly relates to a method for treating and recycling a dimethyl ether carbonylation catalyst activator. According to the method, after impurities are removed from fresh pyridine, a catalyst is activated, after activated tail gas is subjected to the procedures of cooling, gas-liquid separation and water absorption, a gas phase continues to be subjected to trace pyridine removal and then is subjected to harmless emptying, and liquid phases (a liquid phase obtained after gas-liquid separation and a liquid phase obtained after water absorption) return to an impurity removal tank to be repeatedly used. According to the method, the catalyst activating agent is firstly subjected to impurity removal treatment, then the tail gas of the activated gas is recycled, the catalyst activating effect is improved, the tail gas of the activated gas is innovatively recycled, resource waste and environmental pollution are reduced to the maximum extent, and the method has the remarkable environment-friendly characteristic. The method is simple and easy to operate and has a good industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst pretreatment, and specifically relates to a method for treating and recycling an activator of a dimethyl ether carbonylation catalyst. Background Art

[0002] As an important clean energy, ethanol can be mixed with gasoline at a ratio of 10%, and fuel ethanol gasoline can reduce the emissions of carbon monoxide and hydrocarbons in automobile exhaust, which is of great significance for China to solve the problem of air pollution and achieve sustainable development.

[0003] Currently, fuel ethanol is mainly divided into three categories: grain ethanol, non-grain ethanol, and cellulosic ethanol. Grain ethanol is made from grains such as corn and wheat. Since the production of grain ethanol and non-grain ethanol will occupy more arable land, it is gradually being restricted or prohibited. In recent years, domestic and foreign researchers have explored an economical, environmentally friendly and green process route of "syngas → methanol → dimethyl ether → methyl acetate → ethanol". At present, the total domestic production capacity of dimethyl ether plants is high, but the operating rate is less than 50%, only 38%. This route solves problems such as a serious overcapacity of dimethyl ether.

[0004] Currently, a technical route of "dimethyl ether → methyl acetate → ethanol" has been developed in China, that is, dimethyl ether and carbon monoxide undergo a carbonylation reaction to produce methyl acetate, and methyl acetate and hydrogen undergo a hydrogenation reaction to produce ethanol. Among them, the technology for hydrogenating methyl acetate to ethanol is already mature and has been industrialized. However, due to the influence of catalyst effects, further research and development are still needed to obtain better production efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for treating and recycling an activator of a dimethyl ether carbonylation catalyst in view of the problems existing in the prior art. This method can achieve the effects of improving pyridine activation and pyridine recovery, improve resource utilization rate, and reduce environmental pollution. This invention method is simple and easy to operate, innovatively recovers and reuses the tail gas of the activation gas, minimizes resource waste and environmental pollution, and has remarkable environmentally friendly characteristics and good industrial application prospects.

[0006] In order to achieve the above invention purpose, the specific technical solution of the present invention is as follows:

[0007] A method for treating and recycling an activator of a dimethyl ether carbonylation catalyst, which comprises the following steps:

[0008] The fresh pyridine in the storage tank is metered by a metering pump and quantitatively transported. After being treated to remove impurities through two impurity removal tanks, it is mixed with nitrogen heated to a certain temperature and then used to activate the catalyst in the reactor. The tail gas at the reactor outlet undergoes cooling, gas-liquid separation (the main device used is a gas-liquid separation tank), and water absorption process (the main device used is an absorption tank). Then, the gas phase enters the pyridine removal tank, and after removing trace pyridine, it is harmlessly discharged; the liquid obtained from gas-liquid separation (in the gas-liquid separation tank) is returned to the impurity removal tank for reuse; the liquid phase in the water absorption process (absorption tank) first enters the dehydration tank for dehydration and then is returned to the impurity removal tank for reuse. The impurity removal tank and the dehydration tank are periodically dried and regenerated using hot nitrogen.

[0009] As a preferred embodiment of the present application, the treatment and reuse method steps of an activator for a dimethyl ether carbonylation catalyst are as follows:

[0010] (1) Treatment method of the catalyst activator: The activator pyridine enters from the bottom of the impurity removal tank 1 and exits from the top, then enters the impurity removal tank 2 through the side inlet of the impurity removal tank 2 and exits from the bottom of the impurity removal tank 2. The pyridine after two-stage impurity removal is mixed with hot nitrogen and then transported to the catalyst activation reactor for activation;

[0011] (2) Tail gas recovery system: A cooler, a gas-liquid separator, a water absorption tank, a dehydration tank, and a pyridine removal tank are sequentially connected; the cooler cools the pyridine-containing tail gas from the activation reactor; the gas-liquid separator separates the condensed liquid pyridine from the gaseous tail gas; the water absorption tank absorbs the residual gaseous pyridine through circulating spray water to form a pyridine aqueous solution; the dehydration tank dehydrates the pyridine aqueous solution using molecular sieves; the pyridine removal tank absorbs the trace pyridine in the tail gas to meet the emission standard; the separated liquid pyridine is returned to the impurity removal process for recycling.

[0012] In step (1), the liquid hourly space velocity of pyridine is 0.1 - 3 h -1 , specifically, it can be 0.1 h -1 , 0.5 h -1 , 1 h -1、 1.5 h -1 , 2 h -1 , 2.5 h -1 , 3 h -1 and so on.

[0013] As a preferred embodiment of the present application, the (fresh) pyridine in the pyridine storage tank has a water content of 0.02 - 0.2 wt%, an ammonia (NH3) content of 0.005 - 0.02 wt%, and the chloride content is calculated as Cl, with a content of 0.0005 - 0.002 wt%.

[0014] As a preferred embodiment of the present application, the water-containing pyridine enters a two-stage impurity removal tank for impurity removal treatment. The pressure of the first-stage impurity removal tank is 0.1 - 0.6 MPaG (specifically, it can be 0.1 MPaG, 0.2 MPaG, 0.3 MPaG, 0.4 MPaG, 0.5 MPaG, 0.6 MPaG, etc.), and the temperature of the impurity removal tank is 5 - 60 °C (specifically, it can be 5 °C, 10 °C, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, etc.).

[0015] The pressure of the second-stage impurity removal tank is 0.5 - 5.0 MPaG (specifically, it can be 0.5 MPaG, 1 MPaG, 2 MPaG, 3 MPaG, 4 MPaG, 5 MPaG, etc.), and the temperature of the impurity removal tank is 40 - 80 °C (specifically, it can be 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, etc.).

[0016] As a preferred embodiment of the present application, the water-containing pyridine enters the impurity removal tank for impurity removal treatment. The impurity removal agent filled in the impurity removal tank 1 is a combination of one of NaA and modified NaA molecular sieves and one or more of 3A / 4A / 5A molecular sieves, and the volume ratio of NaA to 3A / 4A / 5A is (0.1 - 0.5). The impurity removal agent filled in the impurity removal tank 2 is a combination of UTSA-280 type MOF adsorbent and one or more of 3A / 4A / 5A molecular sieves, and the volume ratio of UTSA-280 to 3A / 4A / 5A is (0.01 - 0.4).

[0017] As a preferred embodiment of the present application, after the water-containing pyridine is subjected to impurity removal, the ammonia (NH3) content in the pyridine is ≤0.0001%, the chloride content is ≤0.0001% in terms of Cl, and the water content is 0 - 0.01%.

[0018] As a preferred embodiment of the present application, the pyridine after impurity removal is mixed with a certain amount of nitrogen at a certain temperature and enters the carbonylation reactor. The temperature of the hot nitrogen is 200 - 400 °C (specifically, it can be 200 °C, 250 °C, 300 °C, 350 °C, 400 °C, etc.), the volume space velocity is 100 - 10000 h-1 (specifically, it can be 100 h-1, 200 h-1, 300 h-1, 400 h-1, 500 h-1, 600 h-1, 700 h-1, 800 h-1, 900 h-1, 1000 h-1, etc.), and the pressure is 0.1 - 2.0 MPaG (specifically, it can be 0.1 MPaG, 0.5 MPaG, 1 MPaG, 1.5 MPaG, 2 MPaG, etc.).

[0019] As a preferred embodiment of the present application, the tail gas in the reactor enters the cooler for cooling. The cooler uses circulating water or chilled water as the cooling medium, and the temperature of the tail gas after cooling is ≤40 °C.

[0020] As a preferred embodiment of the present application, after the tail gas in the reactor is cooled by a cooler, it enters a gas-liquid separator for gas-liquid separation. After gas-liquid separation, the gas phase enters an absorption tank, and after absorption, the gas phase finally enters a de-pyridine tank, and the de-pyridine tank is filled with one or a combination of molecular sieves such as Y and H-MCM-41.

[0021] As a preferred embodiment of the present application, when the liquid phase part in the absorption tank is saturated with absorption, it enters a dehydration tank. After the liquid phase of the absorption tank is dehydrated by the dehydration tank, it returns to the impurity removal tank for reuse, and the dehydration tank is filled with one or a combination of 3A / 4A / 5A molecular sieves.

[0022] As a preferred embodiment of the present application, after the activation is completed, the fillers in the impurity removal tank, the dehydration tank, and the de-pyridine tank are periodically regenerated with hot nitrogen. The temperature of the hot nitrogen regeneration is 100-300 °C (specifically, it can be 200 °C, 250 °C, 300 °C, etc.), and the gas hourly space velocity is 100-1000 h -1 (specifically, it can be 100 h -1 、200 h -1 、300 h -1、 400 h -1 、500 h -1 、600 h -1 、700 h -1 、800 h -1 、900 h -1 、1000 h -1 etc.).

[0023] In the present invention, pyridine is directly mixed with hot nitrogen in a liquid phase after removing impurities to activate the dimethyl ether carbonylation catalyst. After activation, most of the pyridine is recycled through the processes of cooling, gas-liquid separation, and absorption, and the remaining trace pyridine in the tail gas is made harmless and vented through the de-pyridine process.

[0024] Compared with the prior art, the positive effects of the present invention are as follows:

[0025] (1) The method of the present invention has significant environmental friendliness characteristics.

[0026] (2) By removing impurities from the catalyst activator, the catalytic efficiency is effectively improved.

[0027] (3) The present method innovatively recovers and reuses the tail gas of the activation gas, minimizing resource waste and environmental pollution to the greatest extent. This process is not only simple to operate but also shows good industrial application prospects, contributing positively to sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1Process flow diagram of the treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to the present invention. Specific embodiments

[0029] A treatment and recycling method for an activator of a dimethyl ether carbonylation catalyst includes the following steps:

[0030] Fresh pyridine in the pyridine storage tank is metered by a metering pump and enters the first impurity removal tank from the bottom of the first impurity removal tank in a certain amount, and then enters the second impurity removal tank from the side of the second impurity removal tank through the top of the first impurity removal tank for two-stage impurity removal. The pyridine after impurity removal treatment enters the reactor inlet pipeline from the bottom of the second impurity removal tank, is mixed with nitrogen heated to a certain temperature, and then enters the carbonylation reactor to activate the catalyst in the reactor. The tail gas at the reactor outlet enters a cooler for cooling, and after cooling, enters a gas-liquid separator for gas-liquid separation. The liquid phase in the gas-liquid separator directly returns to the impurity removal tank for reuse, and the gas phase part enters an absorption tank. The liquid phase part in the absorption tank enters a dehydration tank after being saturated with absorption, and after dehydration treatment, returns to the impurity removal tank for reuse. The gas phase part in the absorption tank enters a pyridine removal tank from the top of the absorption tank, and after removing trace pyridine in the pyridine removal tank, is discharged harmlessly. After the activation is completed, the first impurity removal tank, the dehydration tank, and the pyridine removal tank are periodically dried and regenerated with hot nitrogen.

[0031] Preferably, the fresh pyridine in the pyridine storage tank has a water content of 0.02 - 0.2 wt%, an ammonia (NH3) content of 0.005 - 0.02 wt%, and the chloride content is calculated as Cl, with a content of 0.0005 - 0.002 wt%.

[0032] Preferably, the water-containing pyridine enters from the bottom of the first impurity removal tank through a metering pump, comes out from the top, enters the second impurity removal tank through the side inlet of the second impurity removal tank, and comes out from the bottom of the second impurity removal tank. The liquid hourly space velocity of the pyridine is 0.1 - 3 h -1 .

[0033] Preferably, the water-containing pyridine enters the two-stage impurity removal tank for impurity removal treatment. The pressure of the first impurity removal tank is 0.1 - 0.6 MPaG, and the temperature is 5 - 60 °C. The pressure of the second impurity removal tank is 0.5 - 5.0 MPaG, and the temperature is 40 - 80 °C.

[0034] Preferably, the water-containing pyridine enters the impurity removal tank for impurity removal treatment. The impurity removal agent filled in the first impurity removal tank is one of NaA and modified NaA molecular sieves and a composition of one or more of 3A / 4A / 5A molecular sieves. The impurity removal agent filled in the second impurity removal tank is a composition of UTSA-280 type MOF adsorbent and one or more of 3A / 4A / 5A molecular sieves.

[0035] Preferably, after the water-containing pyridine is purified, the content of ammonia (NH3) in pyridine is ≤ 0.0001%, the content of chloride calculated as Cl is ≤ 0.0001%, and the water content is 0 - 0.01%.

[0036] Preferably, after purification, the pyridine is mixed with a certain amount of nitrogen gas at a certain temperature and enters the carbonylation reactor. The temperature of the hot nitrogen gas is 200 - 400 °C, and the volume space velocity is 100 - 10000 h -1 , and the pressure is 0.1 - 2.0 MPaG.

[0037] Preferably, the tail gas in the reactor enters a cooler for cooling. The cooler uses circulating water or chilled water as the cooling medium, and the temperature of the tail gas after cooling is ≤ 40 °C.

[0038] Preferably, after the tail gas in the reactor is cooled by the cooler, it enters a gas-liquid separator for gas-liquid separation. After gas-liquid separation, the gas phase enters an absorption tank, and after absorption, the gas phase finally enters a de-pyridine tank. The de-pyridine tank is filled with one or a combination of molecular sieves such as Y and H-MCM-41.

[0039] Preferably, when the liquid phase part in the absorption tank is saturated with absorption, it enters a dehydration tank. After the liquid phase in the absorption tank is dehydrated by the dehydration tank, it returns to the purification tank for reuse. The dehydration tank is filled with one or a combination of 3A / 4A / 5A molecular sieves.

[0040] Preferably, after the activation is completed, the fillers in the purification tank, dehydration tank, and de-pyridine tank are regenerated with hot nitrogen gas at regular intervals. The temperature of the hot nitrogen gas regeneration is 100 - 300 °C, and the gas space velocity is 100 - 1000 h -1 .

[0041] All the features disclosed in this specification, or all the steps in the disclosed methods or processes, except for the mutually exclusive features and / or steps, can be combined in any way.

[0042] Any feature disclosed in this specification (including the claims and abstract), unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example of a series of equivalent or similar features.

[0043] The features and properties in the solution of the present invention will be further described in detail below with reference to the embodiments.

[0044] In this application, the % without marking all represent mass percentage content.

[0045] In the present invention, some conventional operating equipment, devices, and components are omitted or only briefly described.

[0046] Example 1:

[0047] This embodiment provides a method for treating and recycling an activator of a dimethyl ether carbonylation catalyst. The process flow uses Figure 1 , and the specific process steps are the same as the specific implementation manners. In this embodiment, the water content in fresh pyridine is 0.03 wt%, the ammonia (NH3) content is 0.01%, the chloride content (calculated as Cl) is 0.001%. In impurity removal tank 1, NaA and 3A are filled, and the filling volume ratio is 0.4; in impurity removal tank 2, UTSA-280 and 3A molecular sieve are filled, and the filling volume ratio is 0.2, and the liquid hourly space velocity is 1 h -1 , the temperatures of both impurity removal tanks 1 and 2 are 40 °C, the pressure of impurity removal tank 1 is 0.4 MPaG, the pressure of impurity removal tank 2 is 1 MPaG. Control the water content in the pyridine at the outlet of the impurity removal tank <0.002 wt%, the ammonia (NH3) content ≤0.0001%, and the chloride content (calculated as Cl) ≤0.0001%. The pyridine content in the nitrogen entering the reactor is controlled at 6 vol%, the space velocity is 600 h -1 , the temperature is 300 °C, and the pressure is 0.2 MPaG. The tail gas is cooled by circulating water and the temperature is controlled at about 25 °C. The cooled tail gas enters the gas-liquid separation tank for gas-liquid separation. The separated liquid phase is recycled to impurity removal tank 1, and the gas phase enters the absorption tank. The liquid phase in the absorption tank is absorbed until saturated and then enters the dehydration tank for dehydration. Control the water content in the pyridine at the outlet of the dehydration tank <0.1%. After dehydration in the dehydration tank, the liquid phase is recycled to drying tank 1. The gas phase in the absorption tank enters the pyridine removal tank, and Y molecular sieve is filled in the tank, and the gas hourly space velocity is 6000 h -1 , control the pyridine content in the gas phase below 1 ppm to achieve harmless discharge.

[0048] Example 2:

[0049] This embodiment provides a method for treating and recycling an activator of a dimethyl ether carbonylation catalyst. The process flow uses Figure 1 , and the specific process steps are the same as the specific implementation manners. In this embodiment, the water content in fresh pyridine is 0.04 wt%, the ammonia (NH3) content is 0.005%, the chloride content (calculated as Cl) is 0.0007%. In impurity removal tank 1, NaA and 3A / 4A molecular sieve are filled, and the filling volume ratio is 0.3. In impurity removal tank 2, UTSA-280 and 4A molecular sieve are filled, and the filling volume ratio is 0.5, and the liquid hourly space velocity is 0.9 h -1 , the temperature of impurity removal tank 1 is 30 °C, the temperature of impurity removal tank 2 is 60 °C, the pressure of impurity removal drying tank 1 is 0.3 MPaG, the pressure of impurity removal drying tank 2 is 2 MPaG. Control the water content in the pyridine at the outlet of the impurity removal tank <0.002 wt%, the ammonia (NH3) content ≤0.0001%, and the chloride content (calculated as Cl) ≤0.0001%. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 600 h -1, temperature is 300°C. After the tail gas is cooled by circulating water, the temperature is controlled at about 25°C. The cooled tail gas enters the gas-liquid separation tank for gas-liquid separation. The separated liquid phase is recycled to the impurity removal tank 1, and the gas phase enters the absorption tank. The liquid phase in the absorption tank is absorbed until saturated and then enters the dehydration tank for dehydration. The water content in pyridine at the outlet of the dehydration tank is controlled to be <0.1%. After dehydration in the dehydration tank, the liquid phase is recycled to the drying tank 1. The gas phase in the absorption tank enters the pyridine removal tank filled with Y molecular sieve, and the gas hourly space velocity is 6000 h -1 , and the pyridine content in the gas phase is controlled below 1 ppm to achieve harmless discharge.

[0050] Example 3:

[0051] This example provides a method for treating and recycling the activator of the dimethyl ether carbonylation catalyst. The process flow adopts Figure 1 , and the specific process steps are the same as those in the specific implementation manner. In this example, the water content in fresh pyridine is 0.15 wt%, the ammonia (NH3) content is 0.02%, and the chloride (calculated as Cl) content is 0.002%. The impurity removal tank 1 is filled with NaA and 3A molecular sieves, and the filling volume ratio is 0.3. The impurity removal tank 2 is filled with UTSA-280 and 3A / 4A molecular sieves, and the filling volume ratio is 0.3. The liquid hourly space velocity is 0.6 h -1 , the temperature of the impurity removal tank 1 is 40°C, the temperature of the impurity removal tank 2 is 60°C, the pressure of the impurity removal tank 1 is 0.2 MPaG, the pressure of the impurity removal tank 2 is 2 MPaG. The water content in pyridine at the outlet of the impurity removal tank is controlled to be <0.002 wt%, the ammonia (NH3) content is ≤0.0001%, and the chloride (calculated as Cl) content is ≤0.0001%. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 400 h -1 , temperature is 280°C. After the tail gas is cooled by circulating water, the temperature is controlled at about 30°C. The cooled tail gas enters the gas-liquid separation tank for gas-liquid separation. The separated liquid phase is recycled to the drying tank 1, and the gas phase enters the absorption tank. The liquid phase in the absorption tank is absorbed until saturated and then enters the dehydration tank for dehydration. The water content in pyridine at the outlet of the dehydration tank is controlled to be <0.1%. After dehydration in the dehydration tank, the liquid phase is recycled to the impurity removal tank 1. The gas phase in the absorption tank enters the pyridine removal tank filled with Y molecular sieve / H-MCM-41 molecular sieve, and the gas hourly space velocity is 4000 h -1 , and the pyridine content in the gas phase is controlled below 1 ppm to achieve harmless discharge.

[0052] Example 4:

[0053] This example provides a method for treating and recycling the activator of the dimethyl ether carbonylation catalyst. The process flow adopts Figure 1, the specific process steps are the same as those in the specific implementation. In this example, the water content in fresh pyridine is 0.2 wt%, the ammonia (NH3) content is 0.015%, and the chloride content (calculated as Cl) is 0.002%. The impurity removal tank 1 is filled with NaA and 3A / 4A molecular sieves, and the filling volume ratio is 0.5. The impurity removal tank 2 is filled with UTSA-280 and 3A molecular sieves, and the filling volume ratio is 0.2. The liquid hourly space velocity is 0.4 h -1 , the temperature of the impurity removal tank 1 is 20 °C, the temperature of the impurity removal tank 2 is 60 °C, the pressure of the impurity removal tank 1 is 0.4 MPaG, and the pressure of the impurity removal tank 2 is 3 MPaG. Control the water content in the pyridine at the outlet of the impurity removal tank < 0.002 wt%, the ammonia (NH3) content ≤ 0.0001%, and the chloride content (calculated as Cl) ≤ 0.0001%. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 300 h -1 , and the temperature is 300 °C. The tail gas is cooled by circulating water and the temperature is controlled at about 35 °C. The cooled tail gas enters the gas-liquid separation tank for gas-liquid separation. The separated liquid phase is recycled to the impurity removal tank 1, and the gas phase enters the absorption tank. The liquid phase in the absorption tank is absorbed until saturated and then enters the dehydration tank for dehydration. Control the water content in the pyridine at the outlet of the dehydration tank < 0.1%. After dehydration in the dehydration tank, the liquid phase is recycled to the impurity removal tank 1. The gas phase in the absorption tank enters the pyridine removal tank, which is filled with H-MCM-41 molecular sieve, and the gas hourly space velocity is 4000 h -1 , control the pyridine content in the gas phase below 1 ppm to achieve harmless discharge.

[0054] Example 5:

[0055] This example provides a method for regenerating the activator of a dimethyl ether carbonylation catalyst, and the process flow adopts Figure 1 , and the specific process steps are the same as those in the specific implementation method of regeneration. In this example, the temperature of the hot nitrogen is 280 °C.

[0056] The hot nitrogen enters the impurity removal tanks 1, 2, the dehydration tank, and the pyridine removal tank at 800 h -1 respectively to regenerate the fillers in the tanks. After 8 hours of regeneration, the regeneration is completed.

[0057] Example 6:

[0058] This example provides a method for regenerating the activator of a dimethyl ether carbonylation catalyst, and the process flow adopts Figure 1 , and the specific process steps are the same as those in the specific implementation method of regeneration.

[0059] The temperature of the hot nitrogen is 280 °C, and it enters the impurity removal tanks 1 and 2 at 800 h -1 to regenerate the fillers in the impurity removal tanks. After 2 hours of drying, the regeneration of the impurity removal tanks is completed. The temperature of the hot nitrogen is 300 °C, and the hot nitrogen enters at 200 h -1Enter the dehydration tank to regenerate the packing agent in the dehydration tank. After 6 hours of drying time, the regeneration of the dehydration tank is completed. The temperature of the hot nitrogen is 260 °C, and the hot nitrogen is at 400 h -1 Enter the de-pyridine tank to regenerate the packing agent in the de-pyridine tank. After 4 hours of drying time, the regeneration of the drying tank is completed.

[0060] Comparative Example 1:

[0061] The water content in fresh pyridine is 0.2 wt%, the ammonia (NH3) content is 0.009%, and the chloride (calculated as Cl) content is 0.001%. After dehydration in a drying tank filled with one or more compositions of 3A / 4A / 5A, the water content in pyridine is about 0.025 wt%, the ammonia (NH3) content is 0.009 wt%, and the chloride (calculated as Cl) content is 0.001 wt%. The liquid hourly space velocity is 0.8 h -1 Enter the vaporizer. After pyridine is vaporized in the vaporizer, it is mixed with hot nitrogen and then enters the reactor to activate the carbonylation catalyst. The pyridine content in the nitrogen entering the reactor is controlled at 6 vol%, and the space velocity is 600 h -1 , and the temperature is 300 °C.

[0062] Comparative Example 2:

[0063] The water content in fresh pyridine is 0.1 wt%, the ammonia (NH3) content is 0.006%, and the chloride (calculated as Cl) content is 0.0007%. After secondary dehydration in two drying tanks filled with one or more compositions of 3A / 4A / 5A, the water content in pyridine is about 0.02 wt%, the ammonia (NH3) content is 0.006 wt%, and the chloride (calculated as Cl) content is 0.0007 wt%. The liquid hourly space velocity is 0.8 h -1 Enter the vaporizer. After pyridine is vaporized in the vaporizer, it is mixed with hot nitrogen and then enters the reactor to activate the carbonylation catalyst. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 600 h -1 , and the temperature is 300 °C.

[0064] Comparative Example 3:

[0065] A method for using an activator for a dimethyl ether carbonylation catalyst, the specific steps are as follows:

[0066] The water content in fresh pyridine is 0.05 wt%, the ammonia (NH₃) content is 0.02%, and the chloride (calculated as Cl) content is 0.001%. The liquid hourly space velocity is 1 h -1 Enter the vaporizer. After pyridine is vaporized in the vaporizer, it is mixed with hot nitrogen and then enters the reactor to activate the carbonylation catalyst. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 600 h -1 , and the temperature is 300 °C.

[0067] Comparative Example 4:

[0068] A method for using an activator of a dimethyl ether carbonylation catalyst comprises the following specific steps:

[0069] The water content in fresh pyridine is 0.2 wt%, the ammonia (NH3) content is 0.02%, the chloride content (calculated as Cl) is 0.002%, and the liquid hourly space velocity is 0.8 h -1 Enter the vaporizer. After pyridine is vaporized in the vaporizer, it is mixed with hot nitrogen and then enters the reactor to activate the carbonylation catalyst. The pyridine content in the nitrogen entering the reactor is controlled at 8 vol%, and the space velocity is 600 h -1 , and the temperature is 300 °C.

[0070] Table 1 Comparison of experimental data of different activation schemes

[0071]

[0072] By comparing the experimental data of different activation schemes in Table 1, it can be concluded that under the same catalyst and test conditions, for the examples implemented by the method of the present invention, the conversion rate of dimethyl ether in the dimethyl ether carbonylation reaction has been significantly improved, and at the same time, the yield of methyl acetate has also been well improved, indicating that its catalytic activity has been well improved. In addition, through the detection of the catalyst carbon deposition after the catalyst reacts for 200 h, the carbon deposition rate of the examples implemented by the method of the present invention has decreased significantly, indicating that the carbon deposition rate of the catalyst has been effectively slowed down by the method of the present invention. Through the recycling of pyridine, the consumption of pyridine during catalyst activation has been greatly reduced, the emission of pyridine has been effectively controlled, and resource waste and environmental pollution have been minimized.

[0073] The above embodiments only represent the specific implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation to the protection scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application.

[0074] This background art section is provided to generally present the context of the present invention. The work of the currently named inventors, to the extent described in this background art section, and aspects of the work that are not prior art at the time of filing this application are neither expressly nor impliedly admitted to be prior art to the present invention.

Claims

1. A method for treating and recycling an activator of a dimethyl ether carbonylation catalyst, characterized in that It includes the following steps: The metering pump quantitatively transports fresh pyridine in the storage tank. After being treated to remove impurities through two-stage impurity removal tanks, it is mixed with nitrogen heated to a certain temperature and then used to activate the catalyst in the reactor. The tail gas at the reactor outlet goes through the processes of cooling, gas-liquid separation, and water absorption. The gas phase enters the pyridine removal tank, and after removing trace pyridine, it is harmlessly discharged; the liquid separated by gas-liquid separation returns to the impurity removal tank for reuse; the liquid phase obtained from the water absorption process first enters the dehydration tank for dehydration and then returns to the impurity removal tank for reuse, and the impurity removal tank and the dehydration tank are regularly dried and regenerated using hot nitrogen.

2. The treatment and reuse method of an activator for a dimethyl ether carbonylation catalyst as described in claim 1, characterized in that: (1) Treatment method of catalyst activator: Pyridine, the activator, enters from the bottom of the impurity removal tank 1 and exits from the top, then enters the impurity removal tank 2 through the side inlet of the impurity removal tank 2 and exits from the bottom of the impurity removal tank 2. After two-stage impurity removal, the pyridine is mixed with hot nitrogen and then transported to the catalyst activation reactor for activation; the liquid hourly space velocity of pyridine is 0.1 - 3 h -1 ; (2) Tail gas recovery system: A cooler, a gas-liquid separator, a water absorption tank, a dehydration tank, and a pyridine removal tank are sequentially connected; the cooler cools the pyridine-containing tail gas from the activation reactor; the gas-liquid separator separates the condensed liquid pyridine from the gaseous tail gas; the water absorption tank absorbs the residual gaseous pyridine through circulating spray water to form a pyridine aqueous solution; the dehydration tank dehydrates the pyridine aqueous solution using molecular sieves; the pyridine removal tank absorbs trace pyridine in the tail gas to meet the emission standard; the separated liquid pyridine returns to the impurity removal process for recycling.

3. The treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to claim 1 or 2, characterized in that: The water content in the fresh pyridine is 0.02 - 0.2 wt%, the NH₃ content is 0.005 - 0.02 wt%, the chloride content is calculated as Cl, and its content is 0.0005 - 0.002 wt%; after impurity removal of pyridine, the NH₃ content in pyridine ≤ 0.0001%, the chloride content is calculated as Cl, the content ≤ 0.0001%, and the water content is 0 - 0.01%.

4. The treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The pressure of impurity removal tank 1 is 0.1 - 0.6 MPaG, and the temperature of impurity removal tank 1 is 5 - 60 °C. The pressure of impurity removal tank 2 is 0.5 - 5.0 MPaG, and the temperature of impurity removal tank 2 is 40 - 80 °C.

5. The treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The impurity removal agent filled in impurity removal tank 1 is a composition of one of NaA and modified NaA molecular sieves and one or more of 3A / 4A / 5A molecular sieves; the volume ratio of NaA to 3A / 4A / 5A is 0.1 - 0.5; the impurity removal agent filled in impurity removal tank 2 is a composition of UTSA-280 type MOF adsorbent and one or more of 3A / 4A / 5A molecular sieves; the volume ratio of UTSA-280 to 3A / 4A / 5A is 0.01 - 0.

4.

6. The treatment and reuse method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The temperature of the hot nitrogen gas at the reactor inlet is 200 - 400 °C, and the volumetric space velocity is 100 - 10000 h -1 , and the pressure is 0.1 - 2.0 MPaG.

7. The treatment and reuse method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The cooler uses circulating water or chilled water as the cooling medium, and the temperature of the tail gas after cooling ≤ 40 °C.

8. The treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The pyridine removal tank is filled with one or a combination of Y-type and MCM-41 molecular sieves.

9. The treatment and reuse method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that: The dehydration tank is filled with a composition of one or more of 3A / 4A / 5A molecular sieves.

10. The treatment and recycling method of an activator for a dimethyl ether carbonylation catalyst according to claim 2, characterized in that : During regeneration, the temperature of the hot nitrogen is 100 - 300 °C, and the gas hourly space velocity is 100 - 1000 h -1 .

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