Diphenyl carbonate reactive distillation system capable of realizing side-draw

Abstract

The diphenyl carbonate reactive distillation system comprises a reactive distillation tower, a reflux pipeline, a tower top reflux tank, a first condenser, a methanol recovery system, a reflux pump, a side extraction pipeline, a side extraction pump, a buffer tank, a discharge pipeline, a tower bottom pump and a flash tank, a tower top liquid material of the reactive distillation tower enters a tower top reflux tank through a reflux pipeline, and a gas material enters a methanol recovery system after being condensed by a first condenser; controlling the reflux ratio, and refluxing the material in the tower top reflux tank; the reactive distillation column is provided with a height-adjustable side line extraction opening for extracting by-products such as anisole; and separating the reaction organisms through a flash tank to obtain diphenyl carbonate. The device integrates chemical reaction and rectification separation, methanol is separated from a material refluxed at the top of the tower, by-products such as anisole are extracted from a side line, the thermodynamic equilibrium of the reaction is broken, and the reaction is pushed to proceed in the positive direction, so that the conversion rate is increased, and meanwhile, a plurality of by-products are obtained; and the side line extraction position is adjustable, safe and convenient.

Description

Technical Field

[0001] This utility model relates to a diphenyl carbonate reactive distillation system with side-stream extraction, belonging to the technical field of chemical reaction separation equipment. Background Technology

[0002] Diphenyl carbonate is an important environmentally friendly chemical product with a wide range of applications, such as: 1. In the plastics industry, it is an important raw material for the production of engineering plastic polycarbonate. It can be used to synthesize polycarbonate with bisphenol A through transesterification, and can also be used to manufacture polyaryl carbonate and p-hydroxybenzoic acid polyester; 2. It is used to synthesize methyl isocyanate, and then to prepare carbamate insecticides, etc.; 3. It is used as a plasticizer and solvent for polyamides and polyesters, and can also be used as a solvent for cellulose, and as a heat transfer medium in chemical production; 4. It is used to synthesize many important pharmaceutical intermediates, etc.

[0003] The production methods of diphenyl carbonate include the phosgene process, the oxidative carbonylation process, and the transesterification process. The phosgene process is highly toxic and causes severe environmental pollution, and has been gradually phased out. The oxidative carbonylation process uses expensive catalysts and has low efficiency. The transesterification process, which synthesizes diphenyl carbonate by reacting the green chemical raw material dimethyl carbonate (DMC) with phenol, overcomes the shortcomings of the aforementioned two methods and is the most promising route for diphenyl carbonate synthesis. However, the transesterification reaction between dimethyl carbonate and phenol is an equilibrium reaction with a relatively small equilibrium constant, resulting in a limited yield of diphenyl carbonate. This application provides a diphenyl carbonate reactive distillation system with side-stream extraction, which can promptly extract the generated methanol and byproducts, control the reflux ratio, promote the forward reaction, and thus improve product yield and purity. Utility Model Content

[0004] This invention provides a diphenyl carbonate reactive distillation system with side-stream extraction, which integrates chemical reaction and distillation separation. The reaction and product separation are carried out simultaneously in the same column, breaking the thermodynamic equilibrium of the reaction and promoting the reaction in the forward direction, thereby improving the conversion rate.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A diphenyl carbonate reactive distillation system with side-stream extraction capability includes a reactive distillation column, a reflux line, a top reflux tank, a first condenser, a methanol recovery system, a reflux pump, a side-stream extraction line, a side-stream extraction pump, a buffer tank, a discharge line, a bottom pump, and a flash tank.

[0007] The reactive distillation column is equipped with a reboiler at the bottom; the reactive distillation column has a first outlet at the bottom, a second outlet and a reflux inlet at the top, a feed inlet in the middle of the side wall of the reactive distillation column, and a height-adjustable side feed outlet above the middle of the side wall of the reactive distillation column.

[0008] The reflux pipeline includes a first reflux pipe, a second reflux pipe, and a third reflux pipe. One end of the first reflux pipe is connected to the second outlet at the top of the reactive distillation column, and the other end branches into a first liquid pipe and a first gas pipe. The first liquid pipe leads to the top reflux tank, and the first gas pipe is connected to the feed inlet of the first condenser. One end of the second reflux pipe is connected to the outlet of the first condenser, and the other end leads to the methanol recovery system. One end of the third reflux pipe is connected to the outlet of the top reflux tank, and the other end is connected to the inlet of the reflux pump. The pipeline at the outlet of the reflux pump branches into a reflux feed branch and a reflux discharge branch. The reflux feed branch is connected to the reflux inlet at the top of the reactive distillation column, and the reflux discharge branch leads to a buffer tank. Control valves are installed on both the reflux feed branch and the reflux discharge branch to control the reflux ratio.

[0009] One end of the side-source pipeline is connected to the side-source outlet, and the other end is connected to the buffer tank. The side-source pump is installed on the side-source pipeline.

[0010] One end of the discharge pipeline is connected to the first outlet at the bottom of the reactive distillation column, and the other end is connected to the inlet of the flash tank; the bottom pump is located on the discharge pipeline.

[0011] In this application, the height from the bottom to 2 / 5 to 3 / 5 of the height on the side wall of the reactive distillation column is considered the middle section, and the height from 3 / 5 to 9 / 10 of the height is considered the section above the middle section.

[0012] The term "connection" in this application refers to the connection and intercommunication of pipelines.

[0013] This application employs a reactive distillation column, integrating chemical reaction and distillation separation. The reaction and product separation occur simultaneously within the same column, disrupting the thermodynamic equilibrium of the reaction and driving the reaction in the forward direction, thereby increasing conversion rate and reducing side reactions. Methanol is separated from the top of the reactive distillation column, while anisole and other byproducts are collected via side streams, promoting the forward reaction within the column and increasing yield.

[0014] Dimethyl carbonate (DMC) reacts with phenol (PhOH) to produce diphenyl carbonate and methanol, along with other byproducts such as anisole. During the reaction, unreacted dimethyl carbonate and methanol are present at the top of the column and flow out through the reflux line. The dimethyl carbonate, mainly in liquid state, flows into the reflux tank at the top of the column. By controlling the control valves on the reflux feed and reflux discharge branches, the reflux ratio is controlled, with most of it being refluxed back to the reactive distillation column for further reaction, and the remainder entering the buffer tank. Methanol, mainly in gaseous state, is condensed in the first condenser and becomes a byproduct. Anisole and other byproducts are collected through the side-collection line. The bottom of the column contains diphenyl carbonate, unreacted phenol, and catalyst, which are sent to a flash tank for separation to obtain the diphenyl carbonate product.

[0015] As one specific implementation scheme, the aforementioned reactive distillation column is equipped with four or more sections of packing arranged from top to bottom. The side outlet is located between the first two sections of packing from the top, and the feed inlet is located between the third and fourth sections of packing from the top.

[0016] For ease of measurement and control, a mass flow meter, a temperature sensor, and an electrically operated regulating valve are installed on the side-source pipeline upstream of the side-source pump. All of these components are connected to the control system. The control system adjusts the opening degree of the electrically operated regulating valve based on the mass flow rate and temperature.

[0017] The aforementioned mass flow meter, temperature sensor, and electric regulating valve are arranged sequentially from upstream to downstream.

[0018] The control system is existing equipment. This application does not make any special improvements to the structure, principle, or control method of the control system, and will not elaborate further.

[0019] The upstream-to-downstream direction of this application is consistent with the direction of material flow.

[0020] The response time of the above-mentioned electric regulating valve is ≤8 seconds, and the control accuracy is ±1.5℃.

[0021] One specific implementation scheme involves the following structure for the side-stream outlet: a vertically arranged elongated through-hole (the length of the through-hole is aligned with the vertical direction) is provided on the side wall of the reactive distillation column; vertically arranged slide rails are provided on both sides of the through-hole, and a sliding plate is slidably fitted onto the slide rails; the outlet is located on the sliding plate, directly opposite the through-hole; the sliding plate moves up and down along the slide rails, causing the outlet to move along the length of the through-hole; the through-hole is always completely covered during the up-and-down movement of the sliding plate; a seal is provided between the sliding plate and the side wall of the reactive distillation column. The sliding plate is driven by a cylinder or a motor screw mechanism. When driven by a cylinder, the cylinder drive end is connected to the top or bottom of the sliding plate, and the cylinder extension and retraction causes the sliding plate to slide up and down. When driven by a motor screw, one side of the sliding plate is connected to a drive block threaded with the screw; the motor drives the screw to rotate forward and backward, thereby driving the drive block to move the sliding plate up and down.

[0022] The side stream output accounts for 10%-25% of the total distillate from the top of the column, and the flow velocity in the output pipeline is controlled at 0.5-2.0 m / s.

[0023] To improve the purity of the obtained methanol, the methanol recovery system includes a distillation-type methanol separator, a second condenser, and a methanol storage tank. The distillation-type methanol separator has a gas outlet at the top and a liquid outlet at the bottom, with a feed inlet on its side wall. One end of the second reflux pipe is connected to the outlet of the first condenser, and the other end is connected to the feed inlet on the distillation-type methanol separator. The gas inlet at the top of the distillation-type methanol separator, the second condenser, and the methanol storage tank are connected sequentially by pipelines. The liquid outlet at the bottom of the distillation-type methanol separator is connected to the top reflux tank via a pipeline. After secondary separation, methanol with higher purity can be obtained for industrial production.

[0024] To improve safety and material recovery rate, the top of the reflux tank is connected to the first gas pipe via a pipeline. This allows the gas in the reflux tank to enter the first condenser together with the gas in the first gas pipe for condensation, ensuring both safety and improved material recovery efficiency.

[0025] To improve material separation efficiency, a first heat exchanger is installed on the first reflux pipe. When the top outlet temperature exceeds 90℃, it needs to be condensed to 70-80℃ first. Dimethyl carbonate is condensed into liquid and enters the top reflux tank, while the gas (mainly methanol) enters the first condenser and is condensed into liquid.

[0026] To improve safety, a second heat exchanger is installed on the side-source pipeline. When the temperature of the material extracted from the side-source pipeline is too high, it can be cooled down through the second heat exchanger. The heat from the second heat exchanger can be used for preheating of the raw material.

[0027] To improve heating efficiency and temperature control stability, two symmetrically arranged reboilers are installed at the bottom of the reactive distillation column. The reboilers heat the material inside the column, forming a circulation loop with the bottom of the column. Specific installation details for the reboilers, etc., can be found in the product manual or existing mature technologies; these will not be elaborated upon here.

[0028] Any technologies not mentioned in this utility model are based on existing technologies.

[0029] This utility model relates to a diphenyl carbonate reactive distillation system with side-stream extraction, integrating chemical reaction and distillation separation. The reaction and product separation occur simultaneously within the same column. Methanol is separated from the reflux material at the top of the column, while byproducts such as anisole are extracted via side-stream extraction. This disrupts the thermodynamic equilibrium of the reaction, driving the reaction in the forward direction and thus improving the conversion rate. Multiple byproducts are also obtained simultaneously. The side-stream extraction position is adjustable, ensuring safety and convenience, and improving the accuracy of material extraction. The system has a simple structure and is easy to modify. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the reactive distillation system for diphenyl carbonate that can be obtained via a side stream according to this invention. Figure 1 ;

[0031] Figure 2 This is a schematic diagram of the reactive distillation system for diphenyl carbonate that can be obtained via a side stream according to this invention. Figure 2 ;

[0032] Figure 3 This is a schematic diagram of the side-line extraction outlet structure;

[0033] In the diagram, 1 is the reactive distillation column, 101 is the packing, 102 is the elongated through-hole, 103 is the slide plate, 104 is the outlet, 2 is the reflux line, 21 is the first reflux line, 22 is the second reflux line, 23 is the third reflux line, 24 is the reflux feed branch, 25 is the reflux discharge branch, 3 is the top reflux tank, 4 is the first condenser, 5 is the methanol recovery system, 6 is the reflux pump, 7 is the side-collection line, 8 is the side-collection pump, 9 is the buffer tank, 10 is the discharge line, 11 is the bottom pump, 12 is the flash tank, 13 is the control valve, 14 is the reboiler, 15 is the first heat exchanger, 16 is the second heat exchanger, 17 is the mass flow meter, 18 is the temperature sensor, 19 is the electric regulating valve, a is the dimethyl carbonate and catalyst feed, and b is the phenol feed. Detailed Implementation

[0034] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0035] The directional terms used in this application, such as up and down, left and right, horizontal, vertical, top and bottom, are all based on the relative orientations or positional relationships shown in the attached drawings and should not be construed as absolute limitations on this application.

[0036] Example 1

[0037] like Figure 1 As shown, a diphenyl carbonate reactive distillation system capable of side-stream sampling includes a reactive distillation column, a reflux line, a top reflux tank, a first condenser, a methanol recovery system, a reflux pump, a side-stream sampling line, a side-stream sampling pump, a buffer tank, a discharge line, a bottom pump, and a flash tank.

[0038] The reactive distillation column is equipped with a reboiler at the bottom; the reactive distillation column has a first outlet at the bottom, a second outlet and a reflux inlet at the top, a feed inlet at 2 / 5 of the height from the bottom on the side wall of the reactive distillation column, and a height-adjustable side feed outlet at the middle and above (3 / 5 to 4 / 5 of the height from the bottom) on the side wall of the reactive distillation column.

[0039] The reflux pipeline includes a first reflux pipe, a second reflux pipe, and a third reflux pipe. One end of the first reflux pipe is connected to the second outlet at the top of the reactive distillation column, and the other end branches into a first liquid pipe and a first gas pipe. The first liquid pipe leads to the top reflux tank, and the first gas pipe is connected to the feed inlet of the first condenser. One end of the second reflux pipe is connected to the outlet of the first condenser, and the other end leads to the methanol recovery system. One end of the third reflux pipe is connected to the outlet of the top reflux tank, and the other end is connected to the inlet of the reflux pump. The pipeline at the outlet of the reflux pump branches into a reflux feed branch and a reflux discharge branch. The reflux feed branch is connected to the reflux inlet at the top of the reactive distillation column, and the reflux discharge branch leads to a buffer tank. Control valves are installed on both the reflux feed branch and the reflux discharge branch to control the reflux ratio.

[0040] One end of the side-source pipeline is connected to the side-source outlet, and the other end is connected to the buffer tank. The side-source pump is installed on the side-source pipeline.

[0041] One end of the discharge pipeline is connected to the first outlet at the bottom of the reactive distillation column, and the other end is connected to the inlet of the flash tank; the bottom pump is located on the discharge pipeline.

[0042] The aforementioned reactive distillation column integrates chemical reaction and distillation separation, allowing simultaneous reaction and product separation within the same column. This disrupts the thermodynamic equilibrium of the reaction, driving the reaction in the forward direction, thereby increasing conversion rate and reducing side reactions. Methanol is separated at the top of the column, while anisole and other byproducts are collected via a side stream, promoting the forward reaction within the column and increasing yield. Dimethyl carbonate (DMC) reacts with phenol (PhOH) to produce diphenyl carbonate and methanol, along with abundant byproducts such as anisole. During the reaction, unreacted dimethyl carbonate and methanol are collected at the top of the column and flow out through the reflux line. Dimethyl carbonate, primarily liquid, flows into the top reflux tank. By controlling the control valves on the reflux feed and reflux outlet branches, the reflux ratio is controlled, with most of the refluxed back into the reactive distillation column for further reaction, and the remainder entering the buffer tank. Methanol, primarily gaseous, is condensed in the first condenser and becomes a byproduct. Anisole and other byproducts are collected via the side stream. The bottom of the column contains diphenyl carbonate, unreacted phenol, and catalyst, which are then fed into a flash tank for separation to obtain the diphenyl carbonate product.

[0043] Example 2

[0044] Based on Example 1, the following improvements were made: The reactive distillation column is equipped with four sections of packing arranged from top to bottom. The side outlet is located between the first two sections of packing from the top, and the feed inlet is located between the third and fourth sections of packing from the top. For ease of metering and control, such as... Figure 2As shown, a mass flow meter, temperature sensor, and electric regulating valve are installed on the side-source pipeline upstream of the side-source pump. All three are connected to the control system. The control system adjusts the opening degree of the electric regulating valve based on the mass flow rate and temperature. The mass flow meter, temperature sensor, and electric regulating valve are arranged sequentially from upstream to downstream. The response time of the electric regulating valve is ≤8 seconds, and the control accuracy is ±1.5℃.

[0045] Example 3

[0046] Based on Example 2, the following improvements were made: The structure of the side stream outlet is as follows: A vertically arranged elongated through-hole (the length direction of the elongated through-hole is consistent with the vertical direction) is provided on the side wall of the reactive distillation column; slide rails are provided on both sides of the elongated through-hole, and a sliding plate is slidably fitted on the slide rails; the outlet is provided on the sliding plate, which is directly opposite the elongated through-hole. The sliding plate moves up and down along the slide rails, driving the outlet to move along the length direction of the elongated through-hole. During the up and down movement of the sliding plate, the elongated through-hole is always completely covered; a seal is provided between the sliding plate and the side wall of the reactive distillation column. The sliding plate is driven by a cylinder or a motor screw structure. When driven by a cylinder, the driving end of the cylinder is connected to the top or bottom of the sliding plate, and the cylinder extends and retracts, causing the sliding plate to slide up and down. When driven by a motor screw, one side of the sliding plate is connected to a drive block that is threaded with the screw. The motor drives the screw to rotate forward and backward, thereby driving the drive block to move the sliding plate up and down. The side stream output accounts for 18%-22% of the total distillate from the top of the column, and the flow velocity of the output pipeline is controlled at 1.5-1.8 m / s.

[0047] Example 4

[0048] Based on Example 3, the following improvements were made: To improve the purity of the obtained methanol, the methanol recovery system includes a distillation-type methanol separator, a second condenser, and a methanol storage tank. The distillation-type methanol separator has a gas outlet at the top and a liquid outlet at the bottom, and a feed inlet on its side wall. One end of the second reflux pipe is connected to the outlet of the first condenser, and the other end is connected to the feed inlet on the distillation-type methanol separator. The gas inlet at the top of the distillation-type methanol separator, the second condenser, and the methanol storage tank are connected sequentially by pipelines. The liquid outlet at the bottom of the distillation-type methanol separator is connected to the top reflux tank via a pipeline. After secondary separation, methanol with a purity of approximately 99% can be obtained for industrial production.

[0049] Example 5

[0050] Based on Examples 3 or 4, the following improvements were made: To enhance safety and material recovery rate, the top of the reflux tank is connected to the first gas pipe via a pipeline. This allows the gas in the reflux tank to enter the first condenser together with the gas in the first gas pipe, ensuring both safety and improved material recovery efficiency. To improve material separation, a first heat exchanger is installed on the first reflux pipe. When the outlet temperature at the top of the column exceeds 90°C, it needs to be condensed to 70-80°C. Dimethyl carbonate condenses into a liquid and enters the reflux tank, while the gas (mainly methanol) enters the first condenser and condenses into a liquid. To improve safety, a second heat exchanger is installed on the side-collection pipeline. The mass flow meter, temperature sensor, electric regulating valve, and second heat exchanger are sequentially arranged from upstream to downstream. When the temperature of the material collected from the side-collection pipeline is too high, it can be cooled through the second heat exchanger. The heat absorbed by the second heat exchanger can be used for preheating of the raw material. To improve heating efficiency and temperature control stability, two symmetrically arranged reboilers are installed at the bottom of the reactive distillation column. The reboiler is used to heat the material inside the reactive distillation column, forming a circulation with the bottom of the column. Specific installation details for the reboiler, etc., can be found in the product manual or existing mature technologies; these will not be elaborated upon here. Dimethyl carbonate (DMC), the catalyst dichlorodioctenoid, and phenol (PhOH) enter through the feed inlet of the reactive distillation column. The molar ratio of dimethyl carbonate to phenol is 1:1. The mass of dichlorodioctenoid is 1% of the combined mass of dimethyl carbonate and phenol. The reaction temperature is 180℃, the pressure is 0.1 MPa, the reflux ratio is 2, and the yield of diphenyl carbonate reaches over 88%.

[0051] The diphenyl carbonate reactive distillation systems described above, which allow for side-stream collection, integrate chemical reaction and distillation separation. The reaction and product separation occur simultaneously within the same column. Methanol is separated from the reflux material at the top of the column, while byproducts such as anisole are collected via side-stream collection. This disrupts the thermodynamic equilibrium of the reaction, driving the reaction in the forward direction and thus increasing the conversion rate. Multiple byproducts are also obtained simultaneously. The side-stream collection position is adjustable, ensuring safety and convenience, and improving the accuracy of material collection. Furthermore, the system has a simple structure and is easy to modify.

Claims

1. A carbonic acid diphenyl ester reactive rectification system that can be side-drawn, characterized by: The reaction rectification tower, the reflux pipeline, the overhead reflux tank, the first condenser, the methanol recovery system, the reflux pump, the side take pipeline, the side take pump, the buffer tank, the discharge pipeline, the bottom pump and the flash tank are arranged in the reaction rectification system. The reaction rectification tower is provided with a reboiler at the bottom, a first outlet at the bottom, a second outlet and a reflux inlet at the top, and a feed inlet in the middle of the sidewall. The reflux pipeline comprises a first reflux pipeline, a second reflux pipeline and a third reflux pipeline. The first reflux pipeline is communicated with the second outlet at the top of the reaction rectification tower at one end and branched into a first liquid pipeline and a first gas pipeline at the other end. The first liquid pipeline is communicated with the overhead reflux tank.

2. The diphenyl carbonate reactive distillation system of claim 1, wherein: The first gas pipeline is communicated with the feed inlet of the first condenser.

3. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The second reflux pipeline is communicated with the discharge outlet of the first condenser at one end and communicated with the feed inlet of the distillation methanol separation tank at the other end.

4. The diphenyl carbonate reactive distillation system of claim 3, wherein: The third reflux pipeline is communicated with the discharge outlet of the overhead reflux tank at one end and communicated with the inlet of the reflux pump at the other end.

5. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The outlet of the reflux pump is branched into a reflux feed branch and a reflux discharge branch.

6. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The reflux feed branch is communicated with the reflux inlet at the top of the reaction rectification tower.

7. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The reflux discharge branch is communicated with the buffer tank.

8. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The control valves are arranged on the reflux feed branch and the reflux discharge branch to control the reflux ratio.

9. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The side take pipeline is communicated with the side take outlet at one end and communicated with the buffer tank at the other end.

10. The diphenyl carbonate reactive distillation system of claim 1 or 2, wherein: The side take pump is arranged on the side take pipeline. The discharge pipeline is communicated with the first outlet at the bottom of the reaction rectification tower at one end and communicated with the feed inlet of the flash tank at the other end. The bottom pump is arranged on the discharge pipeline. The reaction rectification tower is provided with four or more than four sections of fillers arranged from top to bottom. The side take outlet is arranged between the first two sections of fillers from the top. The feed inlet is arranged between the third section of fillers and the fourth section of fillers from the top. The mass flow meter, the temperature sensor and the electric regulating valve are arranged on the side take pipeline upstream of the side take pump. The mass flow meter, the temperature sensor and the electric regulating valve are signal connected with the control system. The response time of the electric regulating valve is less than or equal to 8 seconds. The control precision of the electric regulating valve is ±1.5℃. The first heat exchanger is arranged on the first reflux pipeline. The overhead reflux tank is communicated with the first gas pipeline through the pipeline at the top. The second heat exchanger is arranged on the side take pipeline. The structure of the side take outlet is that a vertical long-hole is arranged on the sidewall of the reaction rectification tower. The two sides of the long-hole are provided with sliding rails. The sliding rails are slidably connected with a sliding plate. The sliding plate is provided with a take-out port. The take-out port is opposite to the long-hole. The sliding plate moves along the sliding rails to drive the take-out port to move along the length direction of the long-hole. The sliding plate always covers the long-hole during the up and down movement. The sealing is arranged between the sliding plate and the sidewall of the reaction rectification tower. The distillation methanol separation tank is provided with a gas outlet at the top and a liquid outlet at the bottom. The distillation methanol separation tank is provided with a feed inlet on the sidewall. The second reflux pipeline is communicated with the discharge outlet of the first condenser at one end and communicated with the feed inlet of the distillation methanol separation tank at the other end. The gas inlet at the top of the distillation methanol separation tank, the second condenser and the methanol storage tank are communicated in sequence through the pipeline. The liquid outlet at the bottom of the distillation methanol separation tank is communicated with the overhead reflux tank through the pipeline. The reaction rectification tower is provided with two symmetrical reboilers at the bottom.

Images