Resolution methanol impurity removal and purification device

Abstract

The utility model discloses a desorption solution methanol impurity removal and purification device, which is characterized in that a rectifying tower is provided with a feed port, a gas phase outlet, a tower kettle liquid outlet, a gas phase circulation port lower than the feed port, and a reflux port lower than the gas phase outlet and higher than the feed port, and a liquid inlet and a liquid outlet of a reboiler are respectively communicated with the tower kettle liquid outlet and the gas phase circulation port; a liquid inlet of the reflux tank is communicated with the gas phase outlet through a first-stage condenser, the reflux tank provides a distillation sample, and a distribution port of the reflux tank is respectively communicated with the reflux port and the methanol tank through a first throttle valve and a second throttle valve. Compared with the prior art, the desorption solution is recycled, the environment is protected, and the enterprise cost is reduced; in addition, the methanol purity is better, the methanol is recycled with high quality, and the desorption regeneration of the resin adsorption column is effectively ensured.

Description

Technical Field

[0001] This utility model relates to the recycling and utilization of methanol wastewater, and more particularly to a device for removing impurities and purifying methanol from an eluent. Background Technology

[0002] In the production of 2-ethylanthraquinone, fuming sulfuric acid is used as a catalyst. For every ton of 2-ethylanthraquinone produced, 15 tons of waste sulfuric acid are generated. This waste sulfuric acid contains a significant amount of colored organic impurities such as tar. The majority of these colored organic impurities are anthraquinone derivatives, polycyclic aromatic hydrocarbons, and resins. To protect the environment and improve efficiency and reduce costs, the waste sulfuric acid needs to be treated with resin adsorption (decolorization). The resin adsorption column removes the organic impurities from the precipitated and filtered waste sulfuric acid. The colored organic impurities adhere to the inside of the resin adsorption column, and the column discharges qualified sulfuric acid. Therefore, the regeneration of the resin adsorption column requires a large amount of methanol, which in turn generates a large amount of eluent (which is methanol wastewater).

[0003] The eluent contains some organic matter, resulting in decreased purity and failing to meet recycling requirements. Specifically, the diluted eluent is only used for a certain degree of regeneration of the resin adsorption column; however, the decolorization of the resin adsorption column is still not ideal, hindering production quality. Discharging the eluent externally significantly impacts the environment. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems mentioned above, and to provide a methanol purification device for deionized liquid, thereby improving the quality of methanol recovery liquid and enabling its reuse.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A methanol purification apparatus for eluent includes a distillation column, a reboiler, and a reflux tank. The distillation column has a feed inlet, a vapor outlet, a bottom outlet, a vapor circulation port below the feed inlet, and a reflux port below the vapor outlet and above the feed inlet. The reboiler's inlet and outlet are respectively connected to the bottom outlet and the vapor circulation port. The reboiler is used to extract and heat the eluent from the distillation column and to flow vapor-liquid material into the distillation column through the vapor circulation port. The reflux tank's inlet is connected to the vapor outlet through a primary condenser. The reflux tank is used to provide a distillation sample, and its distribution port is connected to the reflux port and a methanol tank through a first throttling valve and a second throttling valve, respectively.

[0007] Compared with the prior art, the beneficial effects of this application include: recycling and reusing the eluent, protecting the environment; compared with the total cost of eliminating the eluent and the cost of a large amount of eluent materials, the main cost of reusing the eluent is heating, thus reducing enterprise costs; in addition, the methanol has better purity, and the high-quality regeneration of methanol effectively ensures the eluent regeneration of the resin adsorption column.

[0008] As an improvement to the above technical solution, the distillation column is equipped with a first liquid level sensor. The column bottom outlet is connected to the column bottom discharge pump, which discharges waste through a third throttle valve. The third throttle valve is electrically connected to the first liquid level sensor. The third throttle valve is used to adjust the opening degree in a reverse correlation according to the degree to which the liquid level in the distillation column is too low in the gas phase circulation port.

[0009] As an improvement to the above technical solution, the methanol tank is buried underground.

[0010] As an improvement to the above technical solution, the two channels of the reboiler are respectively circulated with low-pressure saturated steam and eluent, and the reboiler heats the eluent by low-pressure saturated steam.

[0011] As an improvement to the above technical solution, the reflux tank is equipped with a second liquid level sensor, and a second throttle valve is electrically connected to the second liquid level sensor. The second throttle valve is used to positively adjust the opening of the second throttle valve based on the feedback value of the second liquid level sensor.

[0012] As an improvement to the above technical solution, a secondary preheater is also included, wherein the liquid outlet of the tower bottom is discharged through one flow channel of the secondary preheater, and the other flow channel of the secondary preheater provides the desorption liquid to the feed inlet.

[0013] As an improvement to the above technical solution, the gas phase outlet delivers condensate to the first-stage condenser through one flow channel of the first-stage preheater, and desorbate is delivered to the second-stage preheater through the other flow channel of the first-stage preheater.

[0014] As an improvement to the above technical solution, the distillation column is equipped with a pressure sensor for detecting the pressure at its top, and the reboiler is connected to a steam source through a fourth throttle valve. The fourth throttle valve is used to adjust the opening of the fourth throttle valve in a reverse correlation manner based on the pressure detected by the pressure sensor.

[0015] As an improvement to the above technical solution, the liquid outlet of the column bottom is connected to a drain valve, which is used to drain the distillation column and the reboiler. The primary condenser and the reflux tank are used to drain the liquid through the distillation column. Attached Figure Description

[0016] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0017] Figure 1This is a schematic diagram of the methanol purification device for the analytical solution according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A partial structural schematic diagram of the methanol purification device for the eluent is shown.

[0019] The accompanying drawings are only one specific embodiment of this utility model, and the form and structure of this specific embodiment should not limit the extension of other embodiments.

[0020] Drain valve B1;

[0021] Reboiler E1;

[0022] Primary preheater E21, secondary preheater E22;

[0023] Primary condenser E31, secondary condenser E32, methanol cooler E33;

[0024] First throttle valve F1, second throttle valve F2, third throttle valve F3, fourth throttle valve F4;

[0025] First liquid level sensor L1, second liquid level sensor L2;

[0026] Barometric pressure sensor Q1;

[0027] P1 is the bottom discharge pump, and P2 is the reflux pump.

[0028] Distillation column T1, feed inlet T1-1, vapor outlet T1-2, bottom liquid outlet T1-3, vapor circulation inlet T1-4, reflux inlet T1-5;

[0029] Reflux tank V1. Detailed Implementation

[0030] 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.

[0031] Reference Figure 1 , Figure 2This utility model provides a methanol purification device for deionized liquid, including a distillation column T1, a reboiler E1, and a reflux tank V1. The distillation column T1 is provided with a feed inlet T1-1, a gas phase outlet T1-2, a bottom outlet T1-3, a gas phase circulation port T1-4 below the feed inlet T1-1, and a reflux port T1-5 below the gas phase outlet T1-2 and above the feed inlet T1-1. The inlet and outlet of the reboiler E1 are respectively connected to the bottom outlet T1-3 and the gas phase circulation port V1. Phase circulation port T1-4, reboiler E1 is used to extract and heat the eluent from distillation column T1, reboiler E1 is used to flow vapor-liquid material into distillation column T1 through phase circulation port T1-4, the liquid inlet of reflux tank V1 is connected to vapor outlet T1-2 through primary condenser E31, reflux tank V1 is used to provide distillation sample, and the distribution port of reflux tank V1 is connected to reflux port T1-5 and methanol tank through first throttle valve F1 and second throttle valve F2 respectively.

[0032] It is understandable that there may be some height difference between equipment such as distillation column T1, reflux tank V1, preheater, condenser, and cooler. To ensure material supply between these devices, it is standard practice to install pumps (water pumps). To control the flow of materials into and out of each device, it is standard practice to install on / off valves at the inlet and outlet of the equipment, as well as between the devices, such as ball valves, gate valves, and butterfly valves.

[0033] Reference Figure 1 The reflux tank V1 is equipped with an on / off valve for sampling. The bottoms of the distillation column T1 and the reboiler E1 are connected, forming a communicating vessel.

[0034] In the eluent, the components are listed in order of their proportions: methanol has a boiling point of 64.7℃, water has a boiling point of 100℃, anthraquinone derivatives have a boiling point ≥360℃, polycyclic aromatic hydrocarbons have a boiling point ≥210℃, and resin has a boiling point ≥210℃.

[0035] The operation process of this utility model can include an initial feeding step, a heating and steam overflow step, a continuous waste discharge step, a reflux step, and a recovery step.

[0036] Initial feed procedure: The eluent is pumped into distillation column T1. See [link to eluent feed direction] for details. Figure 1 V shown IN11 V IN12 V IN13 V IN14 .

[0037] In the heating overflow step, when the liquid level in distillation column T1 is 30%, the reboiler E1 is connected to a heat source, such as an electric heating wire or the steam described below. The eluent in distillation column T1 and reboiler E1 is slowly heated. The eluent continues to flow into distillation column T1. The target temperature of the column bottom is controlled at 70-95°C, that is, by controlling the power / current of the electric heating wire, or by introducing low-pressure saturated steam (105-120°C) into reboiler E1.

[0038] Reference Figure 1 The eluent in reboiler E1 is stabilized at 70–95°C. When boiling occurs in the upper part of the eluent, methanol vapor and a small amount of water vapor escape from the liquid surface of distillation column T1 and reboiler E1. The methanol vapor and water vapor are discharged through vapor outlet T1-2 to the primary condenser E31, where they are condensed and liquefied, then buffered in reflux tank V1. (Refer to...) Figure 1 The overflow direction V of methanol vapor / methanol distillation vapor OUT11 V OUT12 V OUT13A V OUT13B Furthermore, the methanol vapor and water vapor can be first heated by the primary preheater, and then condensed by the primary condenser E31.

[0039] It is understandable that methanol vapor escapes from the liquid surface of distillation column T1 and reboiler E1. Therefore, in the eluent of distillation column T1, methanol mainly accumulates in the upper part of the liquid, while there is less methanol in the lower part of the eluent. It is used for waste liquid discharge and receiving heat from reboiler E1. That is, the reboiler has a temperature of 80-95°C, and this temperature flows to the distillation column in a vapor-liquid dual state. The eluent in the column neutralizes this temperature of 80-95°C, and the temperature of the upper part of the eluent / methanol in the column is 68-85°C.

[0040] Reference Figure 1 , Figure 2 When the liquid levels in distillation column T1 and reboiler E1 are close to those at the vapor circulation port T1-4 (i.e., around 60% of the liquid level, for example, when the liquid level is -15 to +3 cm below the lower edge of the vapor circulation port T1-4), a liquid mixture in a vapor-liquid dual-state state (mainly methanol vapor, a small amount of water vapor, and other liquids) surges / fluctuates towards distillation column T1 from the outlet of reboiler E1. Methanol vapor and a small amount of water vapor escape from the liquid surfaces of distillation column T1 and reboiler E1. Furthermore, a thermosiphon circulation loop is formed between distillation column T1 and reboiler E1. (See [link to relevant documentation]). Figure 1 The direction W shown 11 W 12 This facilitates the circulation of liquid and material. Specifically, the boiling and bubbling at the top of reboiler E1 creates a density pressure difference between the upper and lower parts of reboiler E1, generating a driving force that propels the liquid in reboiler E1 upwards. The liquid and material in a vapor-liquid dual state (80-95℃) churn / surge from reboiler E1 into distillation column T1. This circulation allows distillation column T1 to achieve a boiling overflow temperature of 70-95℃, while the bottom of reboiler E1 is continuously replenished with liquid and material.

[0041] Furthermore, when the eluent flows down the column through inlet T1-1, it exhibits a temperature-regulating effect similar to that of the reflux liquid, and methanol vaporization occurs prematurely during its descent. Additionally, inlet T1-1 is equipped with a sprinkler head, a rotating distributor head, and a drip tray.

[0042] On the other hand, the liquid level sensor can be a float-type liquid level sensor, which includes a float (magnetic or mechanical), a guide rod, and a reed switch. The float moves up and down with the liquid level, the reed switch changes the resistance value, and the transmitter outputs a 4-20mA analog output or a digital output after analog-to-digital conversion.

[0043] Liquid level sensors can also be hydrostatic (pressure-type) liquid level sensors, which include a capillary tube (filled with silicone oil), a pressure transmitter, and measure the hydrostatic pressure of the liquid P = ρgh, where ρ is density, g is gravity, and h is liquid height. The pressure is converted into a current signal (analog signal) / digital signal. Liquid level sensors can also be radar level gauges, ultrasonic level sensors, capacitive level sensors, etc.

[0044] For the continuous waste discharge step, samples are taken and analyzed at the outlet of the bottom feed pump P1 / bottom liquid outlet T1-3. If the methanol content of the bottom waste liquid is <0.5%, the bottom feed pump P1 is started to begin continuous waste liquid discharge. See [link to waste liquid discharge direction] for details. Figure 1 V shown OUT21 V OUT22 V OUT23 .

[0045] In some settings, based on the liquid level requirements of distillation column T1 and the overall inlet rate, the power / current of the bottom discharge pump P1 is adjusted, that is, the waste discharge rate of distillation column T1 is adjusted, so that the liquid level of distillation column T1 is maintained at about 60%.

[0046] In some configurations, the distillation column T1 is equipped with a first liquid level sensor L1. The column bottom outlet T1-3 is connected to the column bottom discharge pump P1, which discharges waste through a third throttle valve F3. The third throttle valve F3 is electrically connected to the first liquid level sensor L1. The third throttle valve F3 is used to adjust the opening degree in a reverse correlation manner based on the degree to which the liquid level is lower than that of the gas phase circulation port T1-4 (i.e., the corresponding detection value of the first liquid level sensor L1). For example, when the liquid level in distillation column T1 is ≥15cm lower than the height of the gas circulation port T1-4, the third throttle valve F3 is closed (i.e., fully closed, 0% opening); when the liquid level in distillation column T1 is about 8cm lower than the height of the gas circulation port T1-4, the third throttle valve F3 is opened at about 50%; when the liquid level in distillation column T1 does not exceed the height of the gas circulation port T1-4, the third throttle valve F3 is fully open (i.e., 100% opening), and even the two column bottom discharge pumps P1 are started to meet the full opening flow of the third throttle valve F3.

[0047] Specifically, the throttle valve can be manually controlled, and its corresponding liquid level sensor is integrated with an electronic display screen. For example, when the display feedback value of the first liquid level sensor L1 is -10cm, that is, the liquid level of the distillation column T1 is 10cm lower than the gas phase circulation port, the operator can manually adjust the opening of the third throttle valve F3 to 25%.

[0048] Specifically, the purification unit may be equipped with a DCS (Distributed Control System) commonly used in the chemical industry to achieve real-time monitoring and adjustment of process parameters such as temperature, pressure, flow rate, and liquid level (e.g., PID control, Advanced Process Control (APC)). The DCS system architecture includes sensors, actuators (e.g., throttle valves), PLC modules, and redundant controllers (e.g., Honeywell C300, Yokogawa Centum VP) responsible for real-time control algorithm calculations. The operator station (HMI human-machine interface) displays relevant dynamic graphs.

[0049] Between the sensor and the actuator, an operational amplifier can be used as a simple interpolation mechanism. The analog signal from the sensor is amplified to match the actuator to the corresponding voltage amplitude, i.e., the corresponding opening degree. Alternatively, a PLC module can receive the sensor signal, perform calculations, and control the actuator's workload.

[0050] In the reflux step, when the liquid level in the reflux tank V1 is 30%, the reflux pump P2 is started, and the first throttling valve F1 between the reflux tank V1 and the reflux port T1-5 is opened. The reflux liquid provides the descending liquid phase into the column, which fully contacts the rising gas phase on the tray (or in the packing) to carry out mass and heat transfer, forming multiple equilibrium separations, maintaining the gas-liquid balance in the column, and improving the distillation separation efficiency.

[0051] In addition, the water (high-boiling-point component) in the reflux liquid repeatedly exchanges with the methanol vapor (low-boiling-point component) in the rising steam, causing the methanol vapor (low-boiling-point component) to gradually accumulate more at the top of the column, while the water (high-boiling-point component) settles and accumulates. Therefore, water is further precipitated from the distillate, improving the purity of the methanol recovery liquid.

[0052] In addition, the temperature of the reflux liquid is usually lower than the temperature of the vapor at the top of the column. The introduction of reflux liquid can adjust the temperature gradient inside the column and avoid local overheating or undercooling.

[0053] On the other hand, in some configurations, in order to improve the temperature control effect of the reflux liquid, the reflux liquid needs to have a predetermined low temperature, such as 50°C; therefore, further, it also includes a secondary condenser E32, through which the primary condenser E31 delivers condensate to the reflux tank V1.

[0054] In the recovery step, adjust the opening ratio of the first throttle valve F1 and the second throttle valve F2, and partially reflux the methanol condensate back to the distillation column T1. See [link to relevant documentation]. Figure 1 V shown OUT15A Direction: Some methanol condensate is extracted and deposited into underground methanol tanks. See [link / reference]. Figure 1 V shown OUT15B Direction. Adjust the ratio of reflux flow rate to extraction flow rate; for example, a reflux-to-extraction ratio of 3:2 (i.e., 1.5:1), 2:1, or 5:2 (i.e., 2.5:1) to ensure that the actual distillation purity (methanol tank collection purity) and distillation rate are both at a high level.

[0055] Compared with the prior art, the beneficial effects of this application include: recycling and reusing the eluent, protecting the environment; compared with the total cost of eliminating the eluent and the cost of a large amount of eluent materials, the main cost of reusing the eluent is heating, thus reducing enterprise costs; in addition, the methanol has better purity, and the high-quality regeneration of methanol effectively ensures the eluent regeneration of the resin adsorption column.

[0056] After methanol distillation, the waste liquid discharged from the bottom outlet T1-3 of the tower mainly consists of water (boiling point 100℃), anthraquinone derivatives (boiling point ≥360℃), polycyclic aromatic hydrocarbons (boiling point ≥210℃), and resin (boiling point ≥210℃). This waste liquid is further distilled at the corresponding temperature and / or treated by other physical reactions to separate and recover the corresponding components.

[0057] Ideally, methanol tanks should be buried underground to reduce environmental temperature disturbances, dissipate static electricity, and largely avoid potential ignition sources, thus reducing the risk of methanol fires and explosions. In addition, this reduces methanol volatilization caused by diurnal temperature differences.

[0058] To ensure the low-temperature storage of methanol, a methanol cooler E33 is connected in series between the second throttle valve F2 and the methanol tank.

[0059] In some embodiments of this utility model, a secondary preheater E22 is also included. The bottom outlet T1-3 of the column discharges waste through one flow channel of the secondary preheater E22, and the other flow channel of the secondary preheater E22 provides the eluent to the feed inlet T1-1. That is, the eluent pre-absorbs the residual heat of the waste liquid in the distillation column T1, makes full use of the residual heat, preheats in advance, and improves the rate of methanol separation process.

[0060] It is understandable that heat exchange occurs between the two flow channels of the preheater, which is common knowledge in heat exchangers (coolers / condensers / heaters with dual-flow heat exchange).

[0061] In some other settings, the analytical solution is preheated using electric heating.

[0062] In some embodiments of this utility model, the gas phase outlet T1-2 delivers condensate to the primary condenser E31 through one flow channel of the primary preheater E21, and delivers the eluent to the secondary preheater E22 through the other flow channel of the primary preheater E21; that is, the primary preheater E21 for the eluent is actually a pre-cooling of methanol vapor, so the eluent is further preheated to improve the rate of methanol separation process.

[0063] In some embodiments of this invention, the two channels of the reboiler E1 are respectively circulated with low-pressure saturated steam and the eluent. The reboiler E1 heats the eluent with low-pressure saturated steam (105-120°C). A stable heat source of 105-120°C is maintained in the reboiler E1, ensuring stable temperatures of the eluent within the reboiler E1 and the distillation column T1. Methanol vapor and a small amount of water vapor steadily escape from the distillation column T1.

[0064] In some embodiments of this invention, the distillation column T1 is equipped with a pressure sensor G1 for detecting the pressure at its top. The reboiler E1 is connected to a steam source via a fourth throttle valve F4. The fourth throttle valve F4 is used to adjust its opening degree in a reverse correlation based on the pressure detected by the pressure sensor G1. When the pressure inside the distillation column T1 is too high, the steam flow rate / flow rate of the reboiler E1 is reduced.

[0065] In some embodiments of this invention, the reflux tank V1 is equipped with a second liquid level sensor L2, and a second throttle valve F2 is electrically connected to the second liquid level sensor L2. The second throttle valve F2 is used to positively correlate the opening degree of the second throttle valve F2 based on the feedback value of the second liquid level sensor L2, and may even synchronously positively correlate the opening degree of the first throttle valve F1. Adjusting the first throttle valve F1 and / or the second throttle valve F2 ensures that the opening ratio remains within an optimal range.

[0066] In some embodiments of this utility model, the bottom outlet T1-3 of the column is connected to a drain valve B1, such as a ball valve, butterfly valve, or gate valve. The drain valve B1 is used to drain the distillation column T1 and the reboiler E1, and the primary condenser E31 and the reflux tank V1 are used to drain the distillation column T1.

[0067] Reference Figure 1 The methanol condensate from the primary condenser E31 and reflux tank V1 is pumped to the distillation column T1 by the reflux pump P2, and then discharged by the distillation column T1.

[0068] Before the initial feeding step and after the recovery step, there is a purging step to empty the materials, condensate, etc. in the distillation column T1, reboiler E1 and reflux tank V1.

[0069] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the scope of the technical solution of this utility model.

Claims

1. A device for removing impurities from methanol in an eluent, characterized in that, include: The distillation column (T1) is provided with a feed inlet (T1-1), a vapor phase outlet (T1-2), a bottom liquid outlet (T1-3), a vapor phase circulation port (T1-4) lower than the feed inlet (T1-1), and a reflux port (T1-5) lower than the vapor phase outlet (T1-2) and higher than the feed inlet (T1-1). The reboiler (E1) has its inlet and outlet connected to the bottom outlet (T1-3) of the column and the vapor circulation port (T1-4), respectively. The reboiler (E1) is used to extract the eluent from the distillation column (T1) and heat it. The reboiler (E1) is also used to allow vapor-liquid materials to flow into the distillation column (T1) through the vapor circulation port (T1-4). The reflux tank (V1) has its inlet connected to the gas phase outlet (T1-2) via a primary condenser (E31). The reflux tank (V1) is used to provide distilled samples. The distribution port of the reflux tank (V1) is used to connect to the reflux port (T1-5) and the methanol tank via a first throttle valve (F1) and a second throttle valve (F2), respectively.

2. The methanol purification apparatus for the eluent according to claim 1, characterized in that, The distillation column (T1) is equipped with a first liquid level sensor (L1). The column bottom outlet (T1-3) is connected to the column bottom discharge pump (P1), which discharges waste through a third throttle valve (F3). The third throttle valve (F3) is electrically connected to the first liquid level sensor (L1). The third throttle valve (F3) is used to adjust the opening degree in a reverse correlation according to the degree to which the liquid level of the distillation column (T1) is low at the gas phase circulation port (T1-4).

3. The methanol purification apparatus for the eluent according to claim 1, characterized in that, The methanol tank is buried underground.

4. The methanol purification apparatus for the eluent according to claim 1, characterized in that, The two channels of the reboiler (E1) are respectively through which low-pressure saturated steam and the eluent are passed. The reboiler (E1) heats the eluent by low-pressure saturated steam.

5. The methanol purification apparatus for the eluent according to claim 1, characterized in that, The reflux tank (V1) is equipped with a second liquid level sensor (L2), and a second throttle valve (F2) is electrically connected to the second liquid level sensor (L2). The second throttle valve (F2) is used to positively adjust the opening of the second throttle valve (F2) based on the feedback value of the second liquid level sensor (L2).

6. The apparatus for removing impurities from methanol in the eluent according to any one of claims 1 to 5, characterized in that, It also includes a secondary preheater (E22), through which the liquid outlet (T1-3) of the tower bottom discharges waste through one flow channel of the secondary preheater (E22), and through which the other flow channel of the secondary preheater (E22) supplies the desorbed liquid to the feed inlet (T1-1).

7. The methanol purification apparatus for the eluent according to claim 6, characterized in that, The gas phase outlet (T1-2) delivers condensate to the first-stage condenser (E31) through one flow channel of the first-stage preheater (E21), and delivers desorbate to the second-stage preheater (E22) through the other flow channel of the first-stage preheater (E21).

8. The apparatus for removing impurities from methanol in the eluent according to any one of claims 1 to 5, characterized in that, The distillation column (T1) is equipped with a pressure sensor (G1) for detecting the pressure at its top. The reboiler (E1) is connected to a steam source through a fourth throttle valve (F4). The fourth throttle valve (F4) is used to adjust the opening of the fourth throttle valve (F4) in a reverse correlation based on the pressure detected by the pressure sensor (G1).

9. The apparatus for removing impurities from methanol in the eluent according to any one of claims 1 to 5, characterized in that, The bottom outlet (T1-3) of the column is connected to a drain valve (B1), which is used to drain the distillation column (T1) and the reboiler (E1). The primary condenser (E31) and the reflux tank (V1) are used to drain the distillation column (T1).

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