Ethylene carbonate impurity separation and crystallization device
By controlling the difference between crystallization temperature and condensation point, the ethylene carbonate impurity separation device solves the problems of high energy consumption and impurity discoloration, achieves efficient and low-cost purification of ethylene carbonate, and improves product quality.
Patent Information
- Application Number
- CN202422737907.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-11
AI Technical Summary
The existing ethylene carbonate impurity separation process has high energy consumption, and the impurities easily cause discoloration during reboil, which cannot meet the color change experiment requirements of electrolyte customers.
The crystallization process is adopted to control the crystallization temperature at 35-60℃, utilize the difference in condensation points of different components for separation, and combine the switching of heat exchangers and coolers to achieve cooling and heating control, replacing the traditional 140℃ distillation process.
Significantly reduce energy consumption, reduce material discoloration caused by impurities, improve product purity, meet the quality requirements of electrolyte customers, and reduce production costs.
Smart Images
Figure CN223366276U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of ethylene carbonate separation, in particular to an ethylene carbonate impurity separation and crystallization device. Background Art
[0002] Ethylene carbonate (EC) is an organic solvent with excellent performance. It can dissolve a variety of polymers and is also the main raw material for producing dimethyl carbonate by the ester exchange method. With the rapid development of new energy batteries, ethylene carbonate is also widely used in lithium battery electrolytes. The main functions of ethylene carbonate in lithium battery electrolytes are: first, it inhibits the decomposition of the electrolyte, thereby enhancing the stability of the electrolyte; second, it also exhibits the characteristics of low polarization and long cycle life. In mixed electrolytes, it can also improve the polarization phenomenon and cycle stability of the battery, thereby improving the coulombic efficiency of the battery.
[0003] Battery-grade ethylene carbonate is required to have a purity of 99.99%. The existing impurity separation process for ethylene carbonate mainly uses a distillation system for vacuum separation based on the different boiling points of the components in the crude product. In actual application, this technology uses a large amount of steam and needs to be heated to 140°C, which is energy-intensive and produces some light and heavy component waste liquid, increasing processing costs. Moreover, the impurities in ethylene carbonate easily cause discoloration during reboiling, which cannot meet the color change test requirements of different customer groups of electrolytes. Utility Model Content
[0004] The purpose of the present invention is to address the above-mentioned defects of the prior art and to provide an ethylene carbonate impurity separation and crystallization device, which achieves the separation of impurities by controlling the crystallization process, greatly reducing energy consumption; it also reduces the discoloration of the material and the high energy consumption caused by the reboiling of impurities in ethylene carbonate, thereby improving the quality of the product after purification of ethylene carbonate.
[0005] The utility model discloses an ethylene carbonate impurity separation and crystallization device, and its technical solution is as follows: comprising a tower crystallizer (C101), a refrigeration unit (X101), a heat exchanger (E101), a cooler (E102), a heat transfer medium circulation pump (P102), a heat transfer medium buffer tank (V101), an ethylene carbonate fine product receiving tank (V102), and a non-condensable mother liquor storage tank (V103); the upper part of the tower crystallizer (C101) is connected to the ethylene carbonate raw material storage tank (V105) through a pipeline and a raw material delivery pump (P106); the upper side of the tower crystallizer (C101) is connected to the non-condensable mother liquor storage tank (V103) through a pipeline; the tower crystallizer (C101) The bottom of the tower crystallizer (C101) is connected to the ethylene carbonate fine product receiving tank (V102) through a pipeline, the side inlet of the tower crystallizer (C101) is connected to the tube-side outlet of the cooler (E102) through a circulation pipeline, the tube-side inlet of the cooler (E102) is connected to the tube-side outlet of the heat exchanger (E101) through a pipeline, and the shell-side inlet of the cooler (E102) is connected to the refrigeration unit (X101) through a pipeline; the tube-side inlet of the heat exchanger (E101) is connected to the side-line outlet of the tower crystallizer (C101) through a pipeline and a heat transfer medium circulation pump (P102), and is connected in parallel to the heat transfer medium buffer tank (V101) on the pipeline at the output end of the heat transfer medium circulation pump (P102).
[0006] Preferably, the inlet of the above-mentioned refrigeration unit (X101) is connected to the lower end of the refrigerant buffer storage tank (V104) through a pipeline and a refrigerant circulation pump (P101), and the side line of the refrigerant buffer storage tank (V104) is connected to the shell-side outlet of the cooler (E102) through a pipeline; the refrigerant medium flows downward from the refrigerant buffer storage tank (V104) through the refrigerant circulation pump (P101), the refrigeration unit (X101) and the cooler (E102) and is connected to the refrigerant buffer storage tank (V104).
[0007] Preferably, one side of the above-mentioned refrigeration unit (X101) is connected to the circulating water inlet pipe (b1) and the circulating water outlet pipe (b2) respectively; the shell-side inlet of the heat exchanger (E101) is connected to the hot water inlet pipeline (a1) and the hot water circulation pump (P105), and the shell-side outlet of the heat exchanger (E101) is connected to the hot water return pipeline (a2).
[0008] Preferably, the upper side of the tower crystallizer (C101) is connected to the non-condensable mother liquor storage tank (V103) through a pipeline and an observation mirror (S101).
[0009] Preferably, nitrogen protection pipelines (C1) are respectively installed on the top of the tower crystallizer (C101), the ethylene carbonate fine product receiving tank (V102) and the non-condensable mother liquor storage tank (V103).
[0010] Preferably, a first electric control valve (D1) is installed on the pipeline at the lower end of the above-mentioned heat transfer medium buffer tank (V101), a second electric control valve (D2) is installed on the pipeline at the lower end of the refrigeration medium buffer storage tank (V104), a third electric control valve (D3) is installed on the nitrogen protection pipeline (C1) at the top of the tower crystallizer (C101), and a fourth electric control valve (D4) is installed on the pipeline at the lower end of the tower crystallizer (C101).
[0011] Preferably, a three-way control valve (T101) is installed on the pipeline at the outlet of the above-mentioned refrigeration unit (X101), a first throttle valve (L101) is installed on the pipeline at the shell side outlet of the heat exchanger (E101), a second throttle valve (L102) is installed on the pipeline at the outlet of the raw material delivery pump (P106), a product delivery pump (P103) is installed on the pipeline at the lower end of the ethylene carbonate fine product receiving tank (V102), and a mother liquor pump (P104) is installed on the pipeline at the lower end of the non-condensable mother liquor storage tank (V103).
[0012] The beneficial effects of the present invention are as follows: the present invention changes the original distillation purification process into a crystallization process, and then uses the difference in boiling points of different components for separation instead of using the difference in condensation points for separation. The temperature of the crystallization process is controlled at 35-60°C, replacing the 140°C required for distillation in the distillation tower, thereby reducing energy consumption and the shortcomings of discoloration of the material and high energy consumption caused by the reboiling of impurities in ethylene carbonate. The quality of the purified ethylene carbonate product can be greatly improved, and the requirements of different customer groups for color change experiments of the electrolyte can be met. In addition, through the switching and coordination of the cooler and the heat exchanger, the cooling and heating sweating of the tower crystallizer are effectively controlled, thereby shortening the production cycle, improving product quality, and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;
[0014] Figure 2 This is a schematic structural diagram of Example 2 of the present utility model;
[0015] In the figure above: tower crystallizer C101, refrigeration unit X101, heat exchanger E101, cooler E102, heat transfer medium buffer tank V101, ethylene carbonate fine product receiving tank V102, non-condensable mother liquor storage tank V103, refrigeration medium buffer storage tank V104, ethylene carbonate raw material storage tank V105, refrigerant liquid circulation pump P101, heat transfer medium circulation pump P102, product delivery pump P103, mother liquor pump P104, hot water circulation pump P105, raw material delivery pump P106, observation mirror S101, nitrogen protection pipeline C1, first electric control valve D1, second electric control valve D2, third electric control valve D3, fourth electric control valve D4, first throttle valve L101, second throttle valve L102. DETAILED DESCRIPTION
[0016] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.
[0017] Example 1, with reference to Figure 1 The utility model mentions an ethylene carbonate impurity separation and crystallization device, comprising a tower crystallizer C101, a refrigeration unit X101, a heat exchanger E101, a cooler E102, a heat transfer medium circulation pump P102, a heat transfer medium buffer tank V101, an ethylene carbonate fine product receiving tank V102, and a non-condensable mother liquor storage tank V103. The upper part of the tower crystallizer C101 is connected to the ethylene carbonate raw material storage tank V105 through a pipeline and a raw material delivery pump P106, the upper side of the tower crystallizer C101 is connected to the non-condensable mother liquor storage tank V103 through a pipeline, and the bottom of the tower crystallizer C101 is connected to the non-condensable mother liquor storage tank V103 through a pipeline. The pipeline is connected to the ethylene carbonate fine product receiving tank V102, the side line inlet of the tower crystallizer C101 is connected to the tube side outlet of the cold exchanger E102 through the circulation pipeline, the tube side inlet of the cold exchanger E102 is connected to the tube side outlet of the heat exchanger E101 through the pipeline, and the shell side inlet of the cold exchanger E102 is connected to the refrigeration unit X101 through the pipeline; the tube side inlet of the heat exchanger E101 is connected to the side line outlet of the tower crystallizer C101 through the pipeline and the heat transfer medium circulation pump P102, and is connected in parallel to the heat transfer medium buffer tank V101 on the pipeline at the output end of the heat transfer medium circulation pump P102.
[0018] Preferably, the inlet of the above-mentioned refrigeration unit X101 is connected to the lower end of the refrigerant medium buffer storage tank V104 through a pipeline and a refrigerant circulation pump P101, and the side line of the refrigerant medium buffer storage tank V104 is connected to the shell side outlet of the cooler E102 through a pipeline; the refrigerant medium adopts ethylene glycol aqueous solution, which is connected from the refrigerant medium buffer storage tank V104 downward through the refrigerant circulation pump P101, the refrigeration unit X101 and the cooler E102 in sequence to the refrigerant medium buffer storage tank V104.
[0019] Preferably, one side of the above-mentioned refrigeration unit X101 is respectively connected to the circulating water inlet pipe b1 and the circulating water outlet pipe b2; the shell side inlet of the heat exchanger E101 is connected to the hot water inlet pipeline a1 and the hot water circulation pump P105, and the shell side outlet of the heat exchanger E101 is connected to the hot water return pipeline a2.
[0020] Preferably, the upper side of the tower crystallizer C101 is connected to the non-condensable mother liquor storage tank V103 through a pipeline and an observation mirror S101.
[0021] Preferably, nitrogen protection pipelines C1 are respectively installed on the tops of the tower crystallizer C101, the ethylene carbonate fine product receiving tank V102 and the non-condensable mother liquor storage tank V103.
[0022] Preferably, a first electric control valve D1 is installed on the pipeline at the lower end of the above-mentioned heat transfer medium buffer tank V101, a second electric control valve D2 is installed on the pipeline at the lower end of the refrigeration medium buffer storage tank V104, a third electric control valve D3 is installed on the nitrogen protection pipeline C1 on the upper part of the tower crystallizer C101, and a fourth electric control valve D4 is installed on the pipeline at the lower end of the tower crystallizer C101.
[0023] A first throttle valve L101 is installed on the pipeline at the shell side outlet of the heat exchanger E101, a second throttle valve L102 is installed on the pipeline at the outlet of the raw material delivery pump P106, a product delivery pump P103 is installed on the pipeline at the lower end of the ethylene carbonate fine product receiving tank V102, and a mother liquor pump P104 is installed on the pipeline at the lower end of the non-condensable mother liquor storage tank V103.
[0024] When the utility model is used,
[0025] The ethylene carbonate raw material is injected into the tower crystallizer C101 through the raw material delivery pump P106. After the injection process is completed, the temperature is lowered by utilizing the energy efficiency of the refrigeration unit X101. Then, seed crystals are added to the tower crystallizer C101, and the temperature is controlled to drop and crystallize. After a period of time, the crystals are grown at a constant temperature. Then, the non-condensable mother liquor is filtered and the temperature is controlled to rise. After a period of time, the temperature is kept constant to sweat. After a period of time, the non-condensable mother liquor is filtered and the uncrystallized crude ethylene carbonate flows into the non-condensable mother liquor storage tank V103, while the qualified crystallized product is sent to the ethylene carbonate fine product receiving tank V102. Among them, the mother liquor in the non-condensable mother liquor storage tank V103 is then sent to the distillation tower for recycling, and the qualified product in the ethylene carbonate fine product receiving tank V102 is discharged into the finished product storage tank. The temperature of the entire crystallization process is controlled at 35-60°C, replacing the 140°C required for distillation in the distillation tower. The hot water used is steam condensate. The power consumption of the equipment of the utility model is equivalent to that of the vacuum unit of the vacuum system of the distillation tower, which saves the steam consumed in heating the distillation tower and greatly reduces energy consumption.
[0026] Example 2, the utility model mentioned an ethylene carbonate impurity separation and crystallization device, including a tower crystallizer C101, a refrigeration unit X101, a heat exchanger E101, a cooler E102, a heat transfer medium circulation pump P102, a heat transfer medium buffer tank V101, an ethylene carbonate fine product receiving tank V102, and a non-condensable mother liquor storage tank V103. The upper part of the tower crystallizer C101 is connected to the ethylene carbonate raw material storage tank V105 through a pipeline and a raw material delivery pump P106, the upper side of the tower crystallizer C101 is connected to the non-condensable mother liquor storage tank V103 through a pipeline, and the bottom of the tower crystallizer C101 is connected to the non-condensable mother liquor storage tank V103 through a pipeline. The ethylene carbonate fine product receiving tank V102 is connected through a pipeline, the side line inlet of the tower crystallizer C101 is connected to the tube side outlet of the cooler E102 through a circulation pipeline, the tube side inlet of the cooler E102 is connected to the tube side outlet of the heat exchanger E101 through a pipeline, and the shell side inlet of the cooler E102 is connected to the refrigeration unit X101 through a pipeline; the tube side inlet of the heat exchanger E101 is connected to the side line outlet of the tower crystallizer C101 through a pipeline and a heat transfer medium circulation pump P102, and is connected in parallel to the heat transfer medium buffer tank V101 on the pipeline at the output end of the heat transfer medium circulation pump P102.
[0027] The difference from Example 1 is:
[0028] Reference Figure 2 In this embodiment, a three-way control valve T101 is installed on the outlet pipeline of the refrigeration unit X101, which can connect the pipeline of the pipe-side outlet of the cooler E102 with the pipeline of the pipe-side inlet, thereby achieving better control of the refrigerant medium.
[0029] The above description is merely a preferred embodiment of the present invention. Anyone skilled in the art may utilize the above-described technical solutions to modify the present invention or create equivalent technical solutions. Therefore, any simple modifications or equivalent transformations based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. An ethylene carbonate impurity separation and crystallization device, characterized by: The invention comprises a tower crystallizer (C101), a refrigeration unit (X101), a heat exchanger (E101), a cooler (E102), a heat transfer medium circulation pump (P102), a heat transfer medium buffer tank (V101), an ethylene carbonate fine product receiving tank (V102), and a non-condensable mother liquor storage tank (V103). The upper part of the tower crystallizer (C101) is connected to the ethylene carbonate raw material storage tank (V105) through a pipeline and a raw material delivery pump (P106), the upper side of the tower crystallizer (C101) is connected to the non-condensable mother liquor storage tank (V103) through a pipeline, and the bottom of the tower crystallizer (C101) is connected to the ethylene carbonate fine product receiving tank (V105) through a pipeline and a raw material delivery pump (P106). The product receiving tank (V102) is connected to the side line inlet of the tower crystallizer (C101) through a circulation pipeline, the side line inlet of the cooler (E102) is connected to the tube side outlet of the heat exchanger (E101) through a pipeline, and the shell side inlet of the cooler (E102) is connected to the refrigeration unit (X101) through a pipeline; the tube side inlet of the heat exchanger (E101) is connected to the side line outlet of the tower crystallizer (C101) through a pipeline and a heat transfer medium circulation pump (P102), and is connected in parallel to the heat transfer medium buffer tank (V101) on the pipeline at the output end of the heat transfer medium circulation pump (P102).
2. The ethylene carbonate impurity separation and crystallization device according to claim 1, wherein: The inlet of the refrigeration unit (X101) is connected to the lower end of the refrigerant buffer storage tank (V104) through a pipeline and a refrigerant circulation pump (P101), and the side line of the refrigerant buffer storage tank (V104) is connected to the shell-side outlet of the cooler (E102) through a pipeline; the refrigerant medium flows downward from the refrigerant buffer storage tank (V104) through the refrigerant circulation pump (P101), the refrigeration unit (X101) and the cooler (E102) and is connected to the refrigerant buffer storage tank (V104).
3. The ethylene carbonate impurity separation and crystallization device according to claim 2, wherein: One side of the refrigeration unit (X101) is connected to a circulating water inlet pipe (b1) and a circulating water outlet pipe (b2); the shell-side inlet of the heat exchanger (E101) is connected to a hot water inlet pipeline (a1) and a hot water circulation pump (P105), and the shell-side outlet of the heat exchanger (E101) is connected to a hot water return pipeline (a2).
4. The ethylene carbonate impurity separation and crystallization device according to claim 3, wherein: The upper side of the tower crystallizer (C101) is connected to the non-condensable mother liquor storage tank (V103) through a pipeline and an observation mirror (S101).
5. The ethylene carbonate impurity separation and crystallization device according to claim 4, characterized in that: A nitrogen protection pipeline (C1) is respectively installed on the top of the tower crystallizer (C101), the ethylene carbonate fine product receiving tank (V102) and the non-condensable mother liquor storage tank (V103).
6. The ethylene carbonate impurity separation and crystallization device according to claim 5, characterized in that: A first electric control valve (D1) is installed on the pipeline at the lower end of the heat transfer medium buffer tank (V101), a second electric control valve (D2) is installed on the pipeline at the lower end of the refrigeration medium buffer storage tank (V104), a third electric control valve (D3) is installed on the nitrogen protection pipeline (C1) above the tower crystallizer (C101), and a fourth electric control valve (D4) is installed on the pipeline at the lower end of the tower crystallizer (C101).
7. The ethylene carbonate impurity separation and crystallization device according to claim 6, characterized in that: A three-way control valve (T101) is installed on the outlet pipeline of the refrigeration unit (X101), a first throttle valve (L101) is installed on the shell outlet pipeline of the heat exchanger (E101), a second throttle valve (L102) is installed on the outlet pipeline of the raw material delivery pump (P106), a product delivery pump (P103) is installed on the pipeline at the lower end of the ethylene carbonate fine product receiving tank (V102), and a mother liquor pump (P104) is installed on the pipeline at the lower end of the non-condensable mother liquor storage tank (V103).