Energy-saving device for producing methyl ethyl carbonate
By using dry air cooler and negative pressure distillation technology in the methyl ethyl carbonate production device, combined with the reaction tower intermediate reboiler and the refining tower as heat sources, the energy recycling is realized, the problem of high consumption of circulating water and steam is solved, and production costs and equipment investment is reduced.
Patent Information
- Application Number
- CN202422165246.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-09-04
AI Technical Summary
In the existing methyl ethyl carbonate production equipment, the consumption of circulating water and steam is high, resulting in excessive production costs and failure to effectively utilize the heat of each tower.
Dry air cooler and negative pressure distillation technology are used, combined with the reaction tower intermediate reboiler and the refining tower as heat sources to realize energy recycling, reduce the use of condensing equipment and conveying equipment, and reduce the consumption of steam and water.
It effectively saves the amount of circulating water and steam, reduces production costs, and reduces equipment investment and environmental pollution.
Smart Images
Figure CN223055583U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the production field of cyclic carbonic esters, in particular to an energy-saving device for producing ethyl methyl carbonate. Background Art
[0002] Ethyl methyl carbonate is an organic compound with the molecular formula C4H8O3. It is a colorless transparent liquid, insoluble in water, and can be used in organic synthesis. It is an excellent solvent for lithium battery electrolytes. It is the latest product extended with the increase in the production of dimethyl carbonate and lithium-ion batteries. Since it has both methyl and ethyl groups and has the characteristics of both dimethyl carbonate and diethyl carbonate, it is also a solvent for special spices and intermediates.
[0003] Currently, the transesterification method is mostly used to produce ethyl methyl carbonate. After the reaction to synthesize ethyl methyl carbonate, an electronic-grade ethyl methyl carbonate is obtained by using a rectification column. However, most of the existing devices use the atmospheric rectification method, with circulating water used as the cold source of the condenser at the top of the column and steam used as the heat source at the bottom of the column. The heat of each column is not integrated and utilized, resulting in a high steam unit consumption and high production cost of ethyl methyl carbonate. Summary of the Invention
[0004] The technical problem solved by the utility model lies in providing an energy-saving device for producing ethyl methyl carbonate. The energy-saving device for producing ethyl methyl carbonate provided by this application can effectively save the consumption of circulating water and steam during production, and reduce production costs. In view of this, this application provides an energy-saving device for producing ethyl methyl carbonate, including: reaction tower (C1), reaction tower condenser (E1), reaction tower intermediate reboiler (E2), reaction tower reboiler (E3), reaction tower reflux drum (V1), reaction tower reflux pump (P1), reaction tower discharge pump (P2), catalyst separation system (PK1), preliminary fractionation tower (C2), preliminary fractionation tower condenser (E4), preliminary fractionation tower reflux drum (V3), preliminary fractionation tower reflux pump (P3), preliminary fractionation tower side draw drum (V2), preliminary fractionation tower side draw pump (P4), preliminary fractionation tower bottom pump (P7), purification tower (C3), purification tower reflux drum (V4), purification tower reflux pump (P6), purification tower product cooler (E5), purification tower reboiler (E6), purification tower product tank (V5), purification tower product pump (P5), reaction tower top thermometer (T1), reaction tower middle thermometer (T2), reaction tower pressure gauge (PT1), preliminary fractionation tower pressure gauge (PT2), preliminary fractionation tower thermometer (T3), purification tower pressure gauge (PT3), purification tower thermometer (T4), purification tower level gauge (L4); wherein dimethyl carbonate, methanol and catalyst are added from the middle of the reaction tower (C1). The gas-phase discharge end at the top of the reaction tower (C1) is successively provided with a reaction tower condenser (E1) and a reaction tower reflux drum (V1), and is connected to the feed end of the azeotropic separation system through a reaction tower reflux pump (P1); the liquid-phase discharge end at the bottom of the reaction tower (C1) is connected to the feed end of the catalyst separation system (PK1) through a reaction tower discharge pump (P2); the liquid-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the reaction tower (C1); the gas-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the preliminary fractionation tower (C2); the gas-phase discharge end at the top of the preliminary fractionation tower (C2) is successively provided with a preliminary fractionation tower condenser (E4) and a preliminary fractionation tower reflux drum (V3), and is connected to the feed end of the reaction tower (C1) through a preliminary fractionation tower reflux pump (P3); the side line discharge end of the preliminary fractionation tower (C2) is connected to the feed end of the preliminary fractionation tower side draw drum (V2), and the discharge end of the preliminary fractionation tower side draw drum (V2) is connected to the feed end of the purification tower (C3) through a preliminary fractionation tower side draw pump (P4); the gas-phase end at the top of the purification tower (C3) is connected to the gas-phase end of the shell side of the reaction tower intermediate reboiler (E2), the liquid-phase discharge end of the shell side of the reaction tower intermediate reboiler (E2) is connected to the feed end of the purification tower reflux drum (V4), and the discharge end of the purification tower reflux drum (V4) is transported through a purification tower reflux pump (P6), part of which is connected to the reflux feed end of the purification tower (C3), and part of which is connected to the feed end of the reaction tower (C1).
[0005] The reaction tower condenser (E1) uses an air cooler, and a dry air cooler is adopted. The air cooler is equipped with a fan, and all are controlled by frequency conversion. The reaction tower operates at atmospheric pressure, and the top temperature is controlled at 62 - 68 °C. By using an air cooler to cool the gas-phase material at the top of the reaction tower (C1) with air, a large amount of industrial water can be saved, environmental pollution can be reduced, and infrastructure costs can be lowered. Especially in water-scarce areas, replacing water cooling with air cooling can ease the contradiction of water shortage.
[0006] The initial separation tower (C2) is a vacuum distillation tower. The mixed materials such as ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, and methanol separated from the top of the catalyst separation system (PK1) are in the form of gas phase and are fed into the initial separation tower (C2) through the pipeline at the gas-phase discharge end. A vacuum pump is used to evacuate the initial separation tower reflux drum (V3) and the initial separation tower side draw drum (V2) to a negative pressure, so that both the initial separation tower (C2) and the catalyst separation system (PK1) operate under negative pressure, and the pressure is controlled at 20 kPa - 80 kPaA, which is adjusted according to the display of the initial separation tower pressure gauge (PT2). The gas-phase material of the catalyst separation system (PK1) no longer undergoes condensation treatment. This has the advantage of reducing the use of equipment, thereby reducing investment. At the same time, heat can be brought into the initial separation tower (C2), reducing the use of heat sources in the initial separation tower (C2) and lowering the energy consumption of the product.
[0007] The reaction tower (C1) is equipped with a reaction tower intermediate reboiler (E2). The reaction tower (C1) selects a plate tower with a total of 64 trays. The bottom of the reaction tower intermediate reboiler (E2) is connected to the liquid-phase extraction outlet of the 23rd tray, and the top returns to the top of the 15th tray. The material temperature at the 23rd tray is controlled at 65 - 68 °C. The refining tower (C3) is an atmospheric tower, and the distillation tower pressure is controlled at 0 - 5 KPaG. The temperature of the refining tower is controlled at 90 - 107 °C, which can be used as the heat source for the reaction tower intermediate reboiler (E2). The temperature of the gas phase at the top of the refining tower (C3) after condensation is controlled at 75 - 85 °C, and the condensed material returns to the refining tower reflux drum (V4).
[0008] A liquid level gauge (L1) is installed on the refining tower reflux drum (V4). The normal liquid level of the refining tower reflux drum (V4) is controlled at 100%, and full-liquid operation is implemented to avoid insufficient heat exchange of the gas phase at the top of the refining tower (C3) entering the shell side of the reaction tower intermediate reboiler (E2). The gas-liquid phase enters the refining tower reflux drum (V4), causing fluctuations in the refining tower (C3).
[0009] The present utility model has the following advantages:
[0010] (1) Utilize the temperature difference of materials between each tower to realize the recycling of energy and save steam consumption;
[0011] (2) The primary fractionation column directly feeds in the form of gas phase, bringing in a part of heat, reducing the usage amount of the heat source of the reboiler, and at the same time reducing the usage of condensation equipment and conveying equipment;
[0012] (3) The dry air cooler is adopted at the top of the reaction column, saving a large amount of industrial water, reducing environmental pollution, and lowering the capital construction cost. Description of the Drawings
[0013] Figure 1 It is a schematic diagram of the device of the present utility model. Detailed Embodiments
[0014] The present utility model will be further described below in conjunction with examples. The following embodiments are intended to illustrate the present utility model rather than limit it. For the existing device for producing ethyl methyl carbonate, the present utility model provides an energy-saving device for producing ethyl methyl carbonate, including: reaction tower (C1), reaction tower condenser (E1), reaction tower intermediate reboiler (E2), reaction tower reboiler (E3), reaction tower reflux drum (V1), reaction tower reflux pump (P1), reaction tower product discharge pump (P2), catalyst separation system (PK1), preliminary fractionation tower (C2), preliminary fractionation tower condenser (E4), preliminary fractionation tower reflux drum (V3), preliminary fractionation tower reflux pump (P3), preliminary fractionation tower side draw drum (V2), preliminary fractionation tower side draw pump (P4), preliminary fractionation tower bottom pump (P7), refining tower (C3), refining tower reflux drum (V4), refining tower reflux pump (P6), refining tower product cooler (E5), refining tower reboiler (E6), refining tower product tank (V5), refining tower product pump (P5), reaction tower top thermometer (T1), reaction tower middle thermometer (T2), reaction tower pressure gauge (PT1), preliminary fractionation tower pressure gauge (PT2), preliminary fractionation tower thermometer (T3), refining tower pressure gauge (PT3), refining tower thermometer (T4), refining tower level gauge (L4); wherein dimethyl carbonate, methanol and catalyst are added from the middle of the reaction tower (C1). The gas-phase discharge end at the top of the reaction tower (C1) is successively provided with a reaction tower condenser (E1), a reaction tower reflux drum (V1) and is connected to the feed end of the azeotropic separation system through a reaction tower reflux pump (P1); the liquid-phase discharge end at the bottom of the reaction tower (C1) is connected to the feed end of the catalyst separation system (PK1) through a reaction tower product discharge pump (P2); the liquid-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the reaction tower (C1); the gas-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the preliminary fractionation tower (C2); the gas-phase discharge end at the top of the preliminary fractionation tower (C2) is successively provided with a preliminary fractionation tower condenser (E4), a preliminary fractionation tower reflux drum (V3) and is connected to the feed end of the reaction tower (C1) through a preliminary fractionation tower reflux pump (P3); the side-line discharge end of the preliminary fractionation tower (C2) is connected to the feed end of the preliminary fractionation tower side draw drum (V2), and the discharge end of the preliminary fractionation tower side draw drum (V2) is connected to the feed end of the refining tower (C3) through a preliminary fractionation tower side draw pump (P4); the gas-phase end at the top of the refining tower (C3) is connected to the gas-phase end of the shell side of the reaction tower intermediate reboiler (E2), the liquid-phase discharge end of the shell side of the reaction tower intermediate reboiler (E2) is connected to the feed end of the refining tower reflux drum (V4), and the discharge end of the refining tower reflux drum (V4) is transported through a refining tower reflux pump (P6), part of which is connected to the reflux feed end of the refining tower (C3), and part of which is connected to the feed end of the reaction tower (C1).
[0015] The reaction tower condenser (E1) uses an air cooler, and a dry-type air cooler is adopted. The air cooler is equipped with a fan, and all are controlled by frequency conversion. The reaction tower operates at atmospheric pressure, and the top temperature is controlled at 62 - 68 °C. An air cooler is used to cool the gas-phase material at the top of the reaction tower (C1) by air.
[0016] The preliminary fractionation tower (C2) is a vacuum distillation tower. The mixed materials such as ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, and methanol separated from the top of the catalyst separation system (PK1) are in the form of gas phase and are fed into the preliminary fractionation tower (C2) through the pipeline at the gas-phase discharge end. A vacuum pump is used to evacuate the preliminary fractionation tower reflux drum (V3) and the preliminary fractionation tower side draw drum (V2), so that both the preliminary fractionation tower (C2) and the catalyst separation system (PK1) operate under negative pressure, and the pressure is controlled at 20 kPa - 80 kPaA, and the adjustment is carried out according to the indication of the preliminary fractionation tower pressure gauge (PT2).
[0017] The reaction tower (C1) is equipped with a reaction tower intermediate reboiler (E2). The reaction tower (C1) selects a plate tower with a total of 64 trays. The bottom of the reaction tower intermediate reboiler (E2) is connected to the liquid-phase extraction outlet of the 23rd tray, and the top returns to the top of the 15th tray. The material temperature at the 23rd tray is controlled at 65 - 68 °C. The refining tower (C3) is an atmospheric tower, and the distillation tower pressure is controlled at 0 - 5 KPaG. The temperature of the refining tower thermometer (T4) is controlled at 90 - 107 °C, which can be used as the heat source of the reaction tower intermediate reboiler (E2). The temperature of the gas phase at the top of the refining tower (C3) is controlled at 75 - 85 °C after condensation, and the condensed material returns to the refining tower reflux drum (V4). A liquid level gauge (L1) is installed on the refining tower reflux drum (V4), and the normal liquid level of the refining tower reflux drum (V4) is controlled at 100%.
[0018] A production device with an annual output of 40,000 tons of ethyl methyl carbonate and 10,000 tons of diethyl carbonate is transformed and tested by adopting the technical scheme of this embodiment. The operation results are as follows in the table, which shows that: for the device transformed by adopting the technical scheme of this embodiment, the consumption of circulating water and steam is greatly reduced, and the power consumption increases slightly, but through cost accounting, the cost still decreases.
[0019] The above embodiments are only one implementation form of an energy-saving device for producing ethyl methyl carbonate provided by the present utility model. Other deformations according to the scheme provided by the present utility model, adding or reducing components therein, or applying the present utility model to other technical fields close to the present utility model all belong to the protection scope of the present utility model.
Claims
1. An energy-saving device for producing ethyl methyl carbonate, characterized in that, Including: Reaction tower (C1), reaction tower condenser (E1), reaction tower intermediate reboiler (E2), reaction tower reboiler (E3), reaction tower reflux drum (V1), reaction tower reflux pump (P1), reaction tower product discharge pump (P2), catalyst separation system (PK1), preliminary fractionation tower (C2), preliminary fractionation tower condenser (E4), preliminary fractionation tower reflux drum (V3), preliminary fractionation tower reflux pump (P3), preliminary fractionation tower side draw drum (V2), preliminary fractionation tower side draw pump (P4), preliminary fractionation tower bottom pump (P7), purification tower (C3), purification tower reflux drum (V4), purification tower reflux pump (P6), purification tower product cooler (E5), purification tower reboiler (E6), purification tower product tank (V5), purification tower product pump (P5), reaction tower top thermometer (T1), reaction tower middle thermometer (T2), reaction tower pressure gauge (PT1), preliminary fractionation tower pressure gauge (PT2), preliminary fractionation tower thermometer (T3), purification tower pressure gauge (PT3), purification tower thermometer (T4), purification tower level gauge (L4); wherein dimethyl carbonate, methanol and catalyst are added from the middle of the reaction tower (C1). The gas-phase discharge end at the top of the reaction tower (C1) is successively provided with a reaction tower condenser (E1) and a reaction tower reflux drum (V1), and is connected to the feed end of the azeotropic separation system through the reaction tower reflux pump (P1); the liquid-phase discharge end at the bottom of the reaction tower (C1) is connected to the feed end of the catalyst separation system (PK1) through the reaction tower product discharge pump (P2); the liquid-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the reaction tower (C1); the gas-phase discharge end of the catalyst separation system (PK1) is connected to the feed end of the preliminary fractionation tower (C2); the gas-phase discharge end at the top of the preliminary fractionation tower (C2) is successively provided with a preliminary fractionation tower condenser (E4) and a preliminary fractionation tower reflux drum (V3), and is connected to the feed end of the reaction tower (C1) through the preliminary fractionation tower reflux pump (P3); the side-line discharge end of the preliminary fractionation tower (C2) is connected to the feed end of the preliminary fractionation tower side draw drum (V2), and the discharge end of the preliminary fractionation tower side draw drum (V2) is connected to the feed end of the purification tower (C3) through the preliminary fractionation tower side draw pump (P4); the gas-phase end at the top of the purification tower (C3) is connected to the gas-phase end of the shell side of the reaction tower intermediate reboiler (E2), the liquid-phase discharge end of the shell side of the reaction tower intermediate reboiler (E2) is connected to the feed end of the purification tower reflux drum (V4), and the discharge end of the purification tower reflux drum (V4) is transported through the purification tower reflux pump (P6), a part of which is connected to the reflux feed end of the purification tower (C3), and a part of which is connected to the feed end of the reaction tower (C1).
2. The energy-saving device for producing ethyl methyl carbonate according to claim 1, characterized in that, The reaction tower condenser (E1) uses an air cooler, and a dry air cooler is adopted. The air cooler is equipped with a fan, and all are controlled by frequency conversion.
3. An energy-saving device for producing ethyl methyl carbonate according to claim 1, characterized in that, The preliminary fractionation tower (C2) is a negative-pressure distillation tower. The gas phase of the catalyst separation system (PK1) is directly connected to the feed end of the preliminary fractionation tower (C2) through the pipeline at the gas-phase discharge end. A vacuum pump is used to perform negative-pressure operation on the preliminary fractionation tower reflux drum (V3) and the preliminary fractionation tower side draw drum (V2), so that the preliminary fractionation tower (C2) and the catalyst separation system (PK1) are in negative-pressure operation.
4. An energy-saving device for producing ethyl methyl carbonate according to claim 1, characterized in that, The reaction tower (C1) is equipped with an intermediate reboiler and uses the overhead gas material of the refining tower (C3) as the heat source. The condensed material is returned to the reflux drum (V4) of the refining tower.
5. The energy-saving device for producing ethyl methyl carbonate according to claim 1, characterized in that, A level gauge (L1) is installed on the reflux drum (V4) of the refining tower, and the reflux drum (V4) of the refining tower operates with normal full liquid.