System and process for producing high purity dmc by dmo decarboxylation
By integrating a closed catalyst preparation system and a multi-stage separation system, the problems of easy catalyst deactivation and poor material loop matching were solved, achieving efficient DMC production, producing high-purity and electronic-grade products, and extending the unit's operating cycle.
Patent Information
- Application Number
- CN202611353984.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-02
- Publication Date
- 2026-11-06
AI Technical Summary
Existing DMC production facilities suffer from problems such as easy catalyst deactivation, poor material circuit matching, poor product separation, and short operating cycles, making it difficult to simultaneously and stably produce high-purity and electronic-grade DMC products.
A system integrating closed catalyst preparation, decarbonylation reaction, three-phase product separation, catalyst recovery, and material circulation was designed, including a closed catalyst silo, multi-stage condensation and liquid separation, a complete material loop, and a multi-stage distillation column, to achieve efficient catalyst preparation and efficient product separation and recovery.
It achieves efficient formulation and stable delivery of catalysts, efficient separation of gas-liquid-solid three phases, improves raw material utilization, enables long-term continuous operation, and produces high-purity and electronic-grade DMC products to meet different market demands.
Smart Images
Figure CN123038751A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of DMC production technology, and particularly relates to a system and process for producing high-purity DMC by decarbonylation of DMO. Background Technology
[0002] From the perspective of DMC (dimethyl carbonate) industry development, DMC is an environmentally friendly chemical product that has received widespread attention both domestically and internationally in recent years. DMC possesses excellent reactivity and can replace highly toxic or carcinogenic substances such as phosgene, DMS (dimethyl sulfate), chloromethane, and methyl chloroformate in carbonylation, methylation, esterification, and transesterification reactions in many fields, producing a variety of high-value-added fine chemicals. It has found wide application in pharmaceuticals, pesticides, synthetic materials, dyes, lubricant additives, food flavorings, and electronic chemicals. Furthermore, its non-reactive uses, such as as a solvent, solvent medium, and gasoline additive, are also being or will soon be put into practical use, demonstrating its broad application prospects.
[0003] The DMO (dimethyl oxalate) decarbonylation synthesis of DMC has the advantages of wide availability of raw materials and high atom economy. However, existing similar production facilities suffer from the following shortcomings: catalyst feeding and preparation are mostly open operations, making the catalyst susceptible to air deactivation and resulting in poor metering accuracy; the gas-liquid-solid three-phase product separation equipment is scattered, leading to poor separation of the catalyst carried by the liquid phase material from the solid phase; the material loops between the reaction system, catalyst recovery system, and product post-processing system are poorly matched; the unreacted DMO recovery and recycling process is incomplete; and it is difficult to stably produce both primary and electronic grade DMC products simultaneously from a single unit, resulting in short continuous operation cycles. Therefore, there is an urgent need to develop an integrated production system encompassing closed catalyst preparation, decarbonylation reaction, three-phase product separation, catalyst recovery, material recycling, and product classification and purification. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention proposes an innovative approach and designs a system and process for the decarbonylation of DMO to produce high-purity DMC, which is achieved through the following technical solutions.
[0005] A system for producing high-purity DMC from DMO via decarbonylation includes a raw material tank area for DMO, a catalyst silo, a catalyst preparation unit, a DMO decarbonylation reaction unit, a gas phase product processing unit, a paddle dryer, a flash tank, a crude product tank, and a DMC refining unit. The output of the catalyst silo is connected to the inlet of the catalyst preparation unit. The DMO outlet pipeline in the raw material tank area is divided into two branches: one connected to the inlet of the catalyst preparation unit, and the other connected to the inlet of the DMO decarbonylation reaction unit. The outlet of the prepared material from the catalyst preparation unit is connected to the DMO decarbonylation reaction unit. The gas phase outlet of the DMO decarbonylation reaction unit is connected to the gas phase product processing unit. The gas phase product processing unit is equipped with a non-condensable gas tail gas outlet. The gas phase product processing unit is connected to the flash tank via a liquid separation and multi-stage condensation pipeline; the liquid phase outlet of the DMO decarbonylation reaction unit is connected to a paddle dryer; the paddle dryer outputs two paths: one path sends the gas phase condensate back to the flash tank, and the other path sends the solid phase output to the catalyst processing step; the crude DMC product produced by the flash tank is sent to the crude product tank; the outlet of the crude product tank is connected to the DMC refining unit; the DMC refining unit is equipped with two product outlet pipelines, which are respectively connected to the primary DMC storage tank and the electronic-grade DMC storage tank; the DMC refining unit is also equipped with a circulating DMO return pipeline connected back to the DMO decarbonylation reaction unit; the DMC refining unit is also equipped with a non-condensable gas tail gas outlet that is connected to the tail gas outlet pipeline of the gas phase product processing unit.
[0006] Furthermore, the catalyst preparation unit includes a feeding tank, a catalyst preparation vessel, and a catalyst delivery pump. The catalyst preparation vessel is equipped with a jacketed steam heating device and a stirring paddle.
[0007] Furthermore, the catalyst silo is a sealed silo, integrating a nitrogen replacement interface, drying pipeline, pneumatic conveying pipeline, and weighing and metering module.
[0008] Furthermore, the DMO decarbonylation reaction unit includes a decarbonylation reactor, a reaction heater, and a transfer pump. The reaction heater is connected to the decarbonylation reactor via a circulation pipeline and the transfer pump. The decarbonylation reactor is equipped with a jacketed steam heating device and a stirring paddle.
[0009] Furthermore, the gaseous product processing unit includes a multi-stage condensation device and a liquid separation device.
[0010] Furthermore, the DMC refining unit includes four distillation columns: a light-light removal column, a heavy-light removal column, refining column A, and refining column B. Each column is equipped with a top condenser, a reflux tank, a reflux pump, a bottom reboiler, and a bottom pump.
[0011] A process for producing high-purity DMC from DMO by decarbonylation is characterized by comprising the following steps: S01, Catalyst preparation: After nitrogen replacement and steam drying, the catalyst is sent from the silo to the feed tank via gas conveying; the catalyst in the feed tank is weighed by a weighing device and then flows by gravity to the catalyst preparation kettle, where it is mixed with DMO from the raw material tank area; the prepared catalyst slurry is sent into the decarbonylation reactor via a catalyst delivery pump. SO2, DMO decarbonylation reaction: DMO from the feedstock tank area is mixed with catalyst slurry in the DMO decarbonylation reactor. The reactor is heated by a dual heating method of "jacket heating + circulating heat exchange" to cause the DMO to undergo a decarbonylation reaction to generate DMC and CO. The reaction gas phase is collected from the top of the decarbonylation reactor, and after the entrained liquid is removed by the reaction product separator, it flows back to the reactor. The deliquescent gas phase product enters a multi-stage condenser for cooling. The condensate flows by gravity to the flash tank, and the non-condensable gas enters the tail cooler for further cooling. The condensate is collected in the flash tank, and the tail gas is washed with water and sent out of the boundary area. The crude product in the flash tank is transported to the crude product tank for storage. The reaction liquid phase overflows from the bottom of the reactor to the paddle dryer. After drying and separation, the solid catalyst is directly bagged and sent to the catalyst processing process. The separated gas phase is cooled and sent back to the flash tank for recycling. S03, DMC Refining: The crude product from the crude product tank enters the middle section of the light product removal tower. The non-condensable gas at the top of the condenser is combined with the tail gas generated by the gas processing unit and then sent out. The bottom material is sent to the middle section of the heavy product removal tower. The bottom material of the heavy product removal tower is sent back to the carbonyl removal reactor for recycling, and the top material is sent to the lower part of refining tower A. The top material of refining tower A is cooled and then sent to the primary DMC storage tank, and the bottom material is sent to the lower part of refining tower B. The top material of refining tower B is cooled and then sent to the electronic-grade DMC storage tank. The bottom material that passes the analysis is sent to the primary DMC storage tank, and the unqualified material is returned to the middle section of the heavy product removal tower for re-distillation.
[0012] Furthermore, in the S01 catalyst preparation process, the temperature of the catalyst slurry in the reactor is controlled at 175℃~180℃, and the solid content of the catalyst slurry is controlled at 10%wt~20%wt.
[0013] Furthermore, in the SO2 DMO decarbonylation reaction process: the temperature of the decarbonylation reactor is controlled at 190℃~200℃, and the pressure is controlled at 0.3MPa~0.4MPa; the temperature of the reaction heater is controlled at 200℃~220℃; the gaseous product after liquid removal enters a multi-stage condenser to be cooled to 50℃~80℃; and the temperature of the non-condensable gas tail cooler is controlled at 6℃~10℃.
[0014] Furthermore, in the SO3 DMC refining process: the temperature at the top of the light component removal tower is controlled at 50℃~55℃, and the pressure is controlled at 0.01MPa~0.02MPa; the temperature of the top condenser is controlled at 5℃~8℃; and the temperature at the bottom is controlled at 125℃~130℃, and the pressure is controlled at 0.03MPa~0.05MPa. The temperature at the top of the heavy component removal tower is controlled at 75℃~80℃, and the pressure is controlled at -0.03MPa~-0.05MPa. The temperature of the top condenser is controlled at... The temperature of the first refining column is controlled at 50℃~80℃, the bottom temperature is controlled at 155℃~160℃, and the pressure is controlled at -0.01MPa~-0.02MPa; the top temperature of refining column A and refining column B is controlled at 95℃~98℃, and the pressure is controlled at 0.01MPa~0.02MPa. The top condenser temperature is controlled at 60℃~90℃, the bottom temperature is controlled at 100℃~105℃, and the pressure is controlled at 0.03MPa~0.05MPa.
[0015] Beneficial effects: 1. A sealed catalyst silo with nitrogen purging, drying, pneumatic conveying, and weighing functions is set up. The catalyst is transported and prepared under an inert atmosphere, avoiding catalyst deactivation upon contact with air, and ensuring high metering accuracy. 2. The DMO decarbonylation reaction unit outputs gas and liquid phases respectively. The gas phase enters the gas phase product processing unit for multi-stage condensation and liquid separation; the liquid phase enters the paddle dryer for liquid-solid separation. The solid catalyst is sent for external processing, and the gas phase condensate is recovered to the flash tank, achieving efficient three-phase separation of the reaction products (gas, liquid, and solid). 3. A complete material circulation loop is constructed: the unreacted DMO separated by the DMC refining unit is returned to the DMO decarbonylation reaction unit as recycled DMO, improving raw material utilization and reducing material consumption. 4. The DMC refining unit outputs two products, primary and electronic grade, respectively. One unit can simultaneously produce two specifications of DMC products to meet different market demands. 5. The entire system has sealed pipeline connections between each unit, separate exhaust gas discharge, centralized catalyst recovery and disposal, and the unit can operate continuously for long periods. Attached Figure Description
[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.
[0017] Figure 1 This is a schematic diagram of the system structure of the present invention. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only typical embodiments of the present invention and not all embodiments. They are intended to facilitate understanding by those skilled in the art and do not constitute a limitation on the present invention.
[0019] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Example 1
[0020] This embodiment provides a system and process for producing high-purity DMC from DMO through decarbonylation. The system includes a raw material tank area for DMO, a catalyst silo, a catalyst preparation unit, a DMO decarbonylation reaction unit, a gas phase product processing unit, a paddle dryer, a flash tank, a crude product tank, and a DMC refining unit. The catalyst silo is a sealed silo, integrating a nitrogen replacement interface, drying pipeline, pneumatic conveying pipeline, and weighing module. Its output end is connected to the inlet of the catalyst preparation unit. The DMO outlet pipeline in the raw material tank area is divided into two lines: one line connects to the inlet of the catalyst preparation unit, and the other line connects to the inlet of the DMO decarbonylation reaction unit. The catalyst preparation unit includes a feeding tank, a catalyst preparation vessel, and a catalyst delivery pump. The catalyst preparation vessel is equipped with a jacketed steam heating device and a stirring paddle, and its material outlet is connected to the DMO decarbonylation reaction unit. The DMO decarbonylation reaction unit includes a decarbonylation reactor, a reaction heater, and a delivery pump. The reaction heater is an intelligent temperature-controlled electric heater, which is connected to the decarbonylation reactor via a circulation pipeline and the delivery pump. Equipped with a jacketed steam heating device and a stirring paddle, its gas phase outlet is connected to a gas phase product processing unit. The gas phase product processing unit includes a multi-stage condenser and a liquid separator with a non-condensable gas tail gas outlet, connected to a flash tank via liquid separator and multi-stage condenser pipelines. The liquid phase outlet of the DMO decarbonylation reaction unit is connected to a paddle dryer. The paddle dryer outputs two paths: one path sends the gas phase condensate back to the flash tank, and the other path sends the solid phase output to the catalyst processing step. The DMC crude product produced by the flash tank is sent to a crude product tank; the crude product tank discharges... The port connects to the DMC refining unit; the DMC refining unit includes four distillation columns: a light-weight removal column, a heavy-weight removal column, refining column A, and refining column B. Each column is equipped with a top condenser, reflux tank, reflux pump, bottom reboiler, and bottom pump. Two product discharge pipelines are provided, which are respectively connected to the primary DMC storage tank and the electronic-grade DMC storage tank. The DMC refining unit is also equipped with a circulating DMO return pipeline that connects back to the DMO decarbonylation reaction unit. The DMC refining unit is also equipped with a non-condensable gas tail gas outlet that is connected to the tail gas outlet pipeline of the gas phase product processing unit.
[0021] As a further improvement, the catalyst preparation unit can adopt an A / B dual-system alternating operation mode, preparing the catalyst once every 24 hours to ensure the continuous and stable operation of subsequent processes.
[0022] As a further improvement, the reaction heater can also be a steam-heated heater, which improves operational safety.
[0023] The process flow of this embodiment is as follows.
[0024] S01, Catalyst Preparation: After nitrogen replacement and steam drying, the catalyst is transported from the silo to the feed tank via gas conveying. The catalyst in the feed tank is weighed by a weighing device and then flows by gravity to the catalyst preparation kettle, where it is mixed with DMO from the raw material tank area. Steam is introduced into the jacket of the preparation kettle to stabilize the temperature of the catalyst slurry at 175°C. When the solid content of the catalyst slurry reaches 15%wt, it is sent to the decarbonylation reactor via a catalyst transfer pump.
[0025] SO2, DMO decarbonylation reaction: DMO from the feedstock tank is mixed with catalyst slurry in the DMO decarbonylation reactor, where DMO undergoes a decarbonylation reaction to produce DMC and CO. The reaction equation is as follows: This reaction is endothermic, and a dual heating method of "jacketed heating + circulating heat exchange" (reaction heater temperature set at 210℃) is used to heat the reactor and stabilize its temperature at 193℃. The reactor pressure is stabilized at 0.35MPa by controlling the reactor feed rate and output rate to ensure the continuous and stable progress of the reaction. The decarbonylation reaction products are processed in two parts: gas phase and liquid phase. Reactor gas phase: The reaction products are collected from the top of the decarbonylation reactor in gas phase form, and entrained liquid is removed by the reaction product separator. The dehydrated gas phase products enter a multi-stage condenser and are cooled to 70°C. The condensate flows by gravity to the flash tank. The non-condensable gas enters the tail cooler (cooled by 8°C chilled water) for further cooling to 8°C. The condensate flows into the flash tank. The tail gas (mainly composed of CO, DME, CO2 and other light components) is sent to the circulating water of the refrigeration unit for heat exchange to 40°C. After being washed with water, it is sent out of the boundary area. The crude product after flash evaporation is sent to the crude product tank for storage by the crude product transfer pump. Reactor liquid phase: The DMO and catalyst mixture in the decarbonylation reactor overflows to the paddle dryer. After drying and separation, the solid catalyst is directly bagged and sent to the catalyst processing step, while the separated gas phase is cooled and sent to the flash tank for recycling.
[0026] S03, DMC Refining: The crude DMC product flows sequentially through four distillation columns: a light-light product removal column, a heavy-light product removal column, a refining column A, and a refining column B, to achieve fractional purification of the crude DMC product. The specific process is as follows: Light component removal tower: The crude product from the crude product tank enters the middle section of the light component removal tower to remove dissolved CO, CO2, dimethyl ether, and other light components. The operating temperature at the top of the light component removal tower is 50.2℃ and the pressure is 0.02MPa, while the operating temperature at the bottom of the tower is 128.9℃ and the pressure is 0.036MPa. The vapor at the top of the tower is cooled to 7.3℃ by the condenser and then enters the reflux tank. Part of the condensate is returned to the top of the tower by the reflux pump, and the other part is sent out of the boundary area. The non-condensable gas at the top of the condenser is combined with the tail gas generated by the gas processing unit and then sent out. The material at the bottom of the tower is mainly a mixture of DMO and DMC, which is pumped into the heavy component removal tower by the bottom pump. Heavy separation tower: The bottom material of the light separation tower enters the middle of the heavy separation tower to achieve the initial separation of DMO and DMC; the operating temperature at the top of the heavy separation tower is 79.5℃ and the pressure is -0.03MPa, and the operating temperature at the bottom of the tower is 159.2℃ and the pressure is -0.011MPa; the steam at the top of the tower is cooled to 60℃ by the condenser and then enters the reflux tank. Part of the condensate is returned to the top of the tower by the reflux pump, and the other part is used as feed for the purification tower; the bottom material is mainly DMO, which is pumped back to the carbonyl removal reactor for recycling. Purification Tower A: The primary DMC from the top of the de-weighting tower enters the lower part of purification tower A for deep purification; the operating temperature at the top of purification tower A is 95.6℃ and the pressure is 0.02MPa, and the operating temperature at the bottom of the tower is 101.7℃ and the pressure is 0.036MPa; the steam at the top of the tower is cooled to 80℃ by the condenser and then enters the reflux tank. Part of the condensate is returned to the top of the tower by the reflux pump, and the other part is cooled to 40℃ and then sent to the primary DMC storage tank. The material at the bottom of the tower is sent to purification tower B for further purification. Refining Column B: Dimethyl carbonate from the bottom of Refining Column A enters the lower part of Refining Column B for further deep purification; the operating temperature at the top of Refining Column B is 95.6℃ and the pressure is 0.02MPa, while the operating temperature at the bottom is 101.7℃ and the pressure is 0.036MPa; the vapor at the top of the column is cooled to 80℃ by a condenser and then enters the reflux tank. Part of the condensate is returned to the top of the column by a reflux pump, and the other part is cooled to 40℃ and then sent to the electronic-grade DMC storage tank; the material at the bottom of the column is a mixture of trace amounts of DMO and DMC. After being cooled to 40℃, it is analyzed and found to meet the qualification standards of Grade I DMC, and then sent to the Grade I DMC storage tank. Example 2
[0027] As another embodiment, the difference from Embodiment 1 lies in the process flow: S01, Catalyst preparation: The temperature of the catalyst slurry is stabilized at 180℃ by introducing steam into the jacket of the preparation vessel. When the solid content of the catalyst slurry reaches 20%wt, it is sent into the decarbonylation reactor by the catalyst delivery pump. SO2, DMO decarbonylation reaction: The temperature of the reaction heater is set at 220℃, the temperature of the reactor is stabilized at 195℃ and the pressure is stabilized at 0.3MPa. The gaseous product after liquid removal enters a multi-stage condenser to be cooled to 80℃, and the temperature of the non-condensable gas tail cooler is controlled at 6℃. S03, DMC Refined: Light weight removal tower: Top operating temperature 52.5℃, pressure 0.015MPa; bottom operating temperature 126.0℃, pressure 0.048MPa; Top steam is cooled to 6.2℃ by a condenser before entering the reflux tank. Heavy removal tower: Top operating temperature 77.0℃, pressure -0.04MPa; bottom operating temperature 156.5℃, pressure -0.016MPa; Top steam is cooled to 70℃ by a condenser before entering the reflux tank. Refining column A: Top operating temperature 97.2℃, pressure 0.012MPa; bottom operating temperature 105.0℃, pressure 0.032MPa; Top steam is cooled to 85℃ by a condenser before entering the reflux tank. Refining column B: Top operating temperature 97.2℃, pressure 0.012MPa, bottom operating temperature 105.0℃, pressure 0.032MPa; Top steam is cooled to 85℃ by a condenser before entering the reflux tank. Example 3
[0028] As another embodiment, the difference from Embodiment 1 lies in the process flow: S01, Catalyst preparation: The temperature of the catalyst slurry is stabilized at 178℃ by introducing steam into the jacket of the preparation vessel. When the solid content of the catalyst slurry reaches 12%wt, it is sent into the decarbonylation reactor by the catalyst delivery pump. SO2, DMO decarbonylation reaction: The reaction heater temperature is set at 200℃, the reactor temperature is stabilized at 191.5℃ and the pressure is stabilized at 0.39MPa. The gaseous product after liquid removal enters a multi-stage condenser to be cooled to 55.5℃, and the temperature of the non-condensable gas tail cooler is controlled at 9.4℃. S03, DMC Refined: Light weight removal tower: Top operating temperature 54.8℃, pressure 0.01MPa; bottom operating temperature 130℃, pressure 0.032MPa; Top steam is cooled to 5℃ by a condenser before entering the reflux tank. Heavy removal tower: Top operating temperature 75.8℃, pressure -0.047MPa; bottom operating temperature 155.2℃, pressure -0.02MPa; Top steam is cooled to 77℃ by a condenser before entering the reflux tank. Refining column A: Top operating temperature 96.5℃, pressure 0.014MPa; bottom operating temperature 103.8℃, pressure 0.034MPa; Top steam is cooled to 83℃ by a condenser before entering the reflux tank. Refining column B: Top operating temperature 96.5℃, pressure 0.014MPa, bottom operating temperature 103.8℃, pressure 0.034MPa; Top vapor is cooled to 83℃ by a condenser and then enters the reflux tank; Bottom material, after analysis, does not meet the qualification standard of Grade I DMC and is returned to the middle of the de-weighting column for re-distillation.
Claims
1. A system for the decarbonylation of DMO to produce high-purity DMC, characterized in that: The system includes a raw material tank area for DMO, a catalyst silo, a catalyst preparation unit, a DMO decarbonylation reaction unit, a gas phase product processing unit, a paddle dryer, a flash tank, a crude product tank, and a DMC refining unit. The catalyst silo's output is connected to the inlet of the catalyst preparation unit. The DMO discharge pipeline from the raw material tank area is divided into two lines: one connected to the inlet of the catalyst preparation unit, and the other connected to the inlet of the DMO decarbonylation reaction unit. The outlet of the prepared material from the catalyst preparation unit is connected to the DMO decarbonylation reaction unit. The gas phase outlet of the DMO decarbonylation reaction unit is connected to the gas phase product processing unit. The gas phase product processing unit is equipped with a non-condensable gas tail gas outlet. The liquid separation and multi-stage condensation pipelines are connected to the flash tank; the liquid phase outlet of the DMO decarbonylation reaction unit is connected to the paddle dryer; the paddle dryer outputs two paths: one path sends the gaseous condensate back to the flash tank, and the other path sends the solid phase output to the catalyst processing step; the crude DMC product produced by the flash tank is sent to the crude product tank; the outlet of the crude product tank is connected to the DMC refining unit; the DMC refining unit is equipped with two product outlet pipelines, which are respectively connected to the primary DMC storage tank and the electronic-grade DMC storage tank; the DMC refining unit is also equipped with a circulating DMO return pipeline connected back to the DMO decarbonylation reaction unit; the DMC refining unit is also equipped with a non-condensable gas tail gas outlet that is connected to the tail gas outlet pipeline of the gas phase product processing unit.
2. The system for producing high-purity DMC from DMO by decarbonylation according to claim 1, characterized in that: The catalyst preparation unit includes a feeding tank, a catalyst preparation kettle, and a catalyst delivery pump. The catalyst preparation kettle is equipped with a jacketed steam heating device and a stirring paddle.
3. The system for producing high-purity DMC from DMO by decarbonylation according to claim 1, characterized in that: The catalyst silo is a sealed silo that integrates a nitrogen replacement interface, drying pipeline, pneumatic conveying pipeline, and weighing and metering module.
4. The system for producing high-purity DMC from DMO by decarbonylation according to claim 1, characterized in that: The DMO decarbonylation reaction unit includes a decarbonylation reactor, a reaction heater, and a transfer pump. The reaction heater is connected to the decarbonylation reactor via a circulation pipeline and the transfer pump. The decarbonylation reactor is equipped with a jacketed steam heating device and a stirring paddle.
5. The system for producing high-purity DMC from DMO by decarbonylation according to claim 1, characterized in that: The gaseous product processing unit includes multi-stage condensation equipment and liquid separation equipment.
6. The system for producing high-purity DMC from DMO by decarbonylation according to claim 1, characterized in that: The DMC refining unit includes four distillation columns: a light-weight removal column, a heavy-weight removal column, refining column A, and refining column B. Each column is equipped with a top condenser, a reflux tank, a reflux pump, a bottom reboiler, and a bottom pump.
7. A process for producing high-purity DMC from DMO through decarbonylation, characterized in that, The process includes the following steps: S01, Catalyst preparation: After nitrogen replacement and steam drying, the catalyst is sent from the silo to the feed tank via gas conveying; the catalyst in the feed tank is weighed by a weighing device and then flows by gravity to the catalyst preparation kettle, where it is mixed with DMO from the raw material tank area; the prepared catalyst slurry is sent into the decarbonylation reactor via a catalyst delivery pump. SO2, DMO decarbonylation reaction: DMO from the feedstock tank area is mixed with catalyst slurry in the DMO decarbonylation reactor. The reactor is heated by a dual heating method of "jacket heating + circulating heat exchange" to cause the DMO to undergo a decarbonylation reaction to generate DMC and CO. The reaction gas phase is collected from the top of the decarbonylation reactor, and after the entrained liquid is removed by the reaction product separator, it flows back to the reactor. The deliquescent gas phase product enters a multi-stage condenser for cooling. The condensate flows by gravity to the flash tank, and the non-condensable gas enters the tail cooler for further cooling. The condensate is collected in the flash tank, and the tail gas is washed with water and sent out of the boundary area. The crude product in the flash tank is transported to the crude product tank for storage. The reaction liquid phase overflows from the bottom of the reactor to the paddle dryer. After drying and separation, the solid catalyst is directly bagged and sent to the catalyst processing process. The separated gas phase is cooled and sent back to the flash tank for recycling. S03, DMC Refining: The crude product from the crude product tank enters the middle section of the light product removal tower. The non-condensable gas at the top of the condenser is combined with the tail gas generated by the gas processing unit and then sent out. The bottom material is sent to the middle section of the heavy product removal tower. The bottom material of the heavy product removal tower is sent back to the carbonyl removal reactor for recycling, and the top material is sent to the lower part of refining tower A. The top material of refining tower A is cooled and then sent to the primary DMC storage tank, and the bottom material is sent to the lower part of refining tower B. The top material of refining tower B is cooled and then sent to the electronic-grade DMC storage tank. The bottom material that passes the analysis is sent to the primary DMC storage tank, and the unqualified material is returned to the middle section of the heavy product removal tower for re-distillation.
8. The process for producing high-purity DMC from DMO through decarbonylation according to claim 7, characterized in that, In the S01 catalyst preparation process: the temperature of the catalyst slurry in the reactor is controlled at 175℃~180℃, and the solid content of the catalyst slurry is controlled at 10%wt~20%wt.
9. A process for producing high-purity DMC from DMO by decarbonylation according to claim 7, characterized in that, In the SO2 DMO decarbonylation reaction process: the temperature of the decarbonylation reactor is controlled at 190℃~200℃, and the pressure is controlled at 0.3MPa~0.4MPa; the temperature of the reaction heater is controlled at 200℃~220℃; the gaseous product after liquid removal enters a multi-stage condenser to be cooled to 50℃~80℃; the temperature of the non-condensable gas tail cooler is controlled at 6℃~10℃.
10. A process for producing high-purity DMC from DMO by decarbonylation according to claim 7, characterized in that, In the S03 DMC refining process: the temperature at the top of the light-weight removal tower is controlled at 50℃~55℃, and the pressure is controlled at 0.01MPa~0.02MPa; the temperature of the top condenser is controlled at 5℃~8℃; and the temperature at the bottom is controlled at 125℃~130℃, and the pressure is controlled at 0.03MPa~0.05MPa. The temperature at the top of the heavy-weight removal tower is controlled at 75℃~80℃, and the pressure is controlled at -0.03MPa~-0.05MPa. The temperature of the top condenser is controlled at... The temperature of the first refining column is controlled at 50℃~80℃, the bottom temperature is controlled at 155℃~160℃, and the pressure is controlled at -0.01MPa~-0.02MPa; the top temperature of refining column A and refining column B is controlled at 95℃~98℃, and the pressure is controlled at 0.01MPa~0.02MPa. The top condenser temperature is controlled at 60℃~90℃, the bottom temperature is controlled at 100℃~105℃, and the pressure is controlled at 0.03MPa~0.05MPa.