All-line device for drying air and air separation gas by using Reline deep eutectic solvent
By using the entire equipment and process flow of Reline deep eutectic solvent, the stability and cost problems of air and air separation gas drying in the prior art have been solved, achieving low energy consumption, low volatility and high efficiency gas drying effect, which is in line with the principles of green chemistry.
Patent Information
- Application Number
- CN202422843397.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2034-11-21
AI Technical Summary
Among existing air and air separation gas drying technologies, adsorption methods suffer from poor stability and high cost, while absorption methods suffer from solvent volatility and high energy consumption for water separation, and the application of ionic liquids as dehydrating agents is limited.
Using Reline deep eutectic solvent as a dehydrating agent, a complete equipment and process flow was designed, including steps such as synthesis, purification, flash evaporation, absorption and recovery. Taking advantage of Reline's high hygroscopicity and stability, gas drying was achieved through countercurrent mass transfer and the gas was recycled multiple times.
It achieves low-cost and high-efficiency gas drying, reduces energy consumption and solvent volatility, conforms to green chemistry principles, and improves the stability and drying effect of the device.
Smart Images
Figure CN223760736U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application adopts a solvent absorption method to remove water in air and air separation gas by using Reline deep eutectic solvent as a drying agent, and belongs to the technical field of chemical separation and purification. BACKGROUND
[0002] Gas drying is a basic and universal industrial process, and occupies an important position in China's chemical industry. Air and air separation gas are one of the most important bulk gases, and have wide applications in industries, medical and food industries. In the process of air production and air separation, the water in the air will corrode the separation agent (usually molecular sieve for pressure swing adsorption), equipment and pipeline, etc., and also affect the purity and quality of the subsequent products, which will adversely affect the use of the subsequent products, so it is necessary to dry the air in the pre-process.
[0003] At present, the methods for drying air in industry mainly include adsorption and absorption. The adsorption method uses porous materials such as molecular sieve, silica gel and activated carbon as adsorbent, and completes the drying process of air through pressure swing adsorption. This method has the advantages of high efficiency, wide application scenarios and simple principle, but generally has stability problems, especially when running for a long time in industrial process, the adsorbent is easy to be deactivated, and the cost of adsorption method for drying industrial gas is high, especially in intermittent operation, additional complex system design is also needed to save operation cost. Absorption method is generally used to treat high-throughput gas. The principle of absorption method is to use a solvent with hygroscopicity and the gas to be dried in the absorption tower to realize gas-liquid countercurrent mass transfer, so that the water in the gas is effectively removed. The advantages of absorption method are low cost, large processing capacity, continuous operation and high long-term running stability. Some high-boiling alcohols are generally used as dehydrating agents in industry, such as diethylene glycol, triethylene glycol and DSMO. Although such dehydrating agents have high boiling points, they still have certain volatility in the process of production and use. Therefore, the absorption method inevitably has the disadvantage of secondary volatilization of solvent. At the same time, since the dehydrating agent must be recovered for use, the high energy consumption of the water and alcohol separation process is also a problem faced by the absorption method.
[0004] The core of both absorption and adsorption methods lies in the performance of the absorbent / adsorbent. With the formulation of my country's dual-carbon goals and green chemistry principles, research on absorbents has been a hot topic. Ionic liquids, as molten salts at room temperature, are considered ideal solvents due to their non-volatility and designability. However, their high cost, difficulty in industrial synthesis, and unknown environmental degradability limit their large-scale application. Deep eutectic solvents, complexes synthesized from hydrogen bond donors and acceptors in a specific ratio, possess properties similar to ionic liquids and are therefore considered alternatives. Furthermore, deep eutectic solvents offer advantages such as low raw material cost, simple synthesis, and easy degradation, making them a green and ideal solvent. Due to their strong polarity and complex hydrogen bond network, deep eutectic solvents exhibit a strong affinity for water, making them a potentially viable dehydrating agent.
[0005] Reline, the first and most widely studied deep eutectic solvent, possesses properties similar to ionic liquids, but is more stable, simpler to synthesize, and uses readily available and economical raw materials, costing only 1 / 10 of ionic liquids. The essence of gas drying is the removal of water vapor from volatile gases. Reline itself has a complex hydrogen bond network, exhibiting extremely strong hygroscopicity and water capacity. First, the solubility and selectivity of water, air, oxygen, and nitrogen in Reline were calculated using the COSMO-SAC model, demonstrating the theoretical feasibility of using Reline for drying air and air separation gases. [Utility Model Content]
[0006] The purpose of this invention is to synthesize Reline deep eutectic solvent as a dehydrating agent to replace traditional organic solvents in the drying process of air and air separation gases. Considering the environmental friendliness of Reline and its potential feasibility for dehydration, this invention designs a complete apparatus and process flow for industrial air and air separation gas drying based on the synthesis process and physicochemical properties of Reline. Experimental and computational studies have shown that this apparatus and method have excellent drying performance, low energy consumption, and other advantages, which are highly consistent with the principles of green chemistry and have significant advantages compared to existing processes.
[0007] This utility model is achieved through the following technical solution.
[0008] The utility model relates to a full line device for drying air and air separation gas by using Reline deep eutectic solvent, which is characterized by comprising a Reline synthesis reaction tank (B1), a Reline purification flash tank (F1), a filler absorption tower (T1), a Reline recovery flash tower (F2), a heat exchanger (E1), a heater (H1), a first condenser (C1), a second condenser (C2) and a third condenser (C3). The Reline synthesis reaction tank (B1) is provided with choline chloride (S1) and urea (S2) inlets, and the bottom of the Reline synthesis reaction tank (B1) is provided with a fresh Reline deep eutectic solvent (S3) outlet. The fresh Reline deep eutectic solvent (S3) outlet is connected with the Reline purification flash tank (F1) feed inlet through a pipeline. The upper part of the Reline purification flash tank (F1) is provided with a flash steam (S4) outlet, which is connected with the first condenser (C1). The corresponding condensate water (S5) outlet of the first condenser is connected with the water inlet of the heat exchanger (E1) through a pipeline. The water outlet of the heat exchanger (E1) is not shown in the figure, and the heat exchanger is a conventional technology. The bottom of the Reline purification flash tank (F1) is provided with a fresh dry Reline deep eutectic solvent (S6) outlet, which is connected with the absorbent feed inlet of the filler absorption tower (T1) through a pipeline. The bottom of the filler absorption tower (T1) is provided with a water-rich Reline deep eutectic solvent (S9) outlet, which is connected with another channel inlet of the heat exchanger (E1) through a pipeline. The other channel outlet of the heat exchanger (E1) is connected with the feed inlet of the Reline recovery flash tower (F2) through a heater (H1) and a pipeline. The bottom discharge outlet of the Reline recovery flash tower (F2) is connected with the other channel inlet of the heat exchanger (E1) through a pipeline (circulating flash pipeline), which can realize the circulation dehydration of the water-rich Reline deep eutectic solvent (S9). At the same time, the bottom discharge outlet of the Reline recovery flash tower (F2) is connected with the absorbent feed inlet of the filler absorption tower (T1) through a pipeline (this connection is not shown in the figure), which is used for recycling and reuse of the Reline deep eutectic solvent. The upper part of the Reline recovery flash tower (F2) is provided with a recovery flash steam (S12) outlet, which is connected with the inlet of the third condenser (C3), and is used for condensing the recovery flash steam into liquid water and discharging.
[0009] The filler absorption tower (T1) is provided with a wet gas (S7) inlet, which is located at the lower part of the filler absorption tower (T1). The upper part of the filler absorption tower (T1) is provided with a dry gas (S8) outlet, which is connected with the second condenser (C2).
[0010] The filler absorption tower (T1) is provided with a reagent feeding port at the first theoretical plate of the filler (from top to bottom), and a wet gas (S7) inlet at the bottom, and the number of theoretical plates of the filler absorption tower (T1) is 5-15, which is designed according to requirements.
[0011] The reline purification flash tank (F1) and the reline recovery flash tower (F2) are provided with an air pipe (S10) according to requirements.
[0012] In the utility model, when the pipeline is connected, the valve can be installed according to requirements. The pipeline between the reline recovery flash tower (F2) and the heat exchanger (E1) is provided with a valve, and the pipeline (circulating flash pipeline) between the reline recovery flash tower (F2) and the filler absorption tower (T1) is provided with a valve.
[0013] The process for drying air and air separation gas by using the device mainly includes the following steps:
[0014] Firstly, the choline chloride (S1) and urea (S2) powders are fed into the synthesis reaction tank (B1), and are stirred and heated at 80 DEG C and 101.325kpa for 8h; after the reaction is completed, the fresh reline deep eutectic solvent material (S3) is transported into the flash tank (F1), and is subjected to low-pressure (50kpa and below) and high-temperature (100 DEG C and above) flash for 12h, so as to ensure that the water is completely removed and the dryness is purified; the fresh dry reline deep eutectic solvent (S6) is introduced into the filler absorption tower (T1) from the first theoretical plate of the filler (from top to bottom), and the wet gas is introduced into the tower from the bottom; the gas and liquid are countercurrently contacted in the filler, and after the mass transfer is completed, the dry gas (S8) is collected from the top of the tower, and the water-rich reline deep eutectic solvent (S9) after water absorption is collected from the bottom of the tower.
[0015] The water-rich reline deep eutectic solvent (S9) is recovered, and the specific operation is that the water-rich reline deep eutectic solvent (S9) after being introduced from the bottom of the filler absorption tower (T1) is subjected to heat exchange in the heat exchanger (E1) and then is heated in the heater (H1), and is introduced into the recovery flash tank (F2); since the reline is almost not volatile, the reline can be separated from water vapor by one flash recovery operation in the flash tank, and if the water absorption amount is relatively large, the reline can be separated and recovered by circulating flash; the reline deep eutectic solvent after being separated and recovered by the recovery flash tank (F2) is introduced into the filler absorption tower (T1) again through the circulating pipeline after heat recovery; after the filler absorption tower (T1) and the recovery flash tank (F2) are used for multiple times, the performance of the reline may be reduced or the quality of the reline may be lost, so the quality of the reline can be supplemented accordingly.
[0016] The utility model discloses a preferred embodiment, its characterized in that the reaction tank (B1) in the choline chloride and urea molar quantity are mixed according to 1:2.
[0017] The utility model discloses a preferred embodiment, according to the physical and chemical properties of Reline, the operating pressure of the filler absorption tower (T1) is 1-5atm, the operating temperature is 5-25 DEG C, preferably 15 DEG C, the theoretical tray number (N) is 5-15, preferably 10, and the feed position of the moisture in the filler absorption tower (T1) is the Nth, and N is the bottom plate.
[0018] According to another preferred embodiment of the utility model, its characterized in that the operating pressure of the Reline recovery flash tank (F2) is 0.3-0.5atm, and the operating temperature is 120-150 DEG C.
[0019] According to another preferred embodiment of the utility model, its characterized in that the air and air separation gas can be any one of air, nitrogen and oxygen.
[0020] According to another preferred embodiment of the utility model, its characterized in that the ratio of the total amount of drying agent and the mass of the gas to be dried is 0.5:1-4:1.
[0021] According to another preferred embodiment of the utility model, its characterized in that the moisture content of the dried gas is about 1%, and the moisture content of the dried gas is less than 100ppm.
[0022] [Advantages]
[0023] Compared with the prior art, the utility model has the following advantages:
[0024] (1) the utility model principle is simple, and the operation is convenient, and the drying effect is outstanding, and has very strong feasibility, and Reline can greatly improve the drying effect under the premise that the raw material cost is equivalent to ordinary organic matter.
[0025] (2) Reline has good degradability and low volatility, and will not be secondarily volatilized during generation, use and transportation, and no by-products are generated during the synthesis process, and the energy consumption of the recovery process is low, and the emission of greenhouse gases is reduced, and the whole process is extremely consistent with the principles of green chemistry.
DRAWINGS
[0026] The utility model discloses a preferred embodiment, and the process route diagram of the air and air separation gas of Reline is designed as follows: Figure 1
[0027] In the figure, B1 - stirred synthesis tank; F1 - purification flash tank; T1 - packed absorption column; F2 - recovery flash tank, H1 - heater, C1 - first condenser, C2 - second condenser, C3 - third condenser; S1 - choline chloride; S2 - urea, S3 - fresh Reline deep eutectic solvent, S4 - flash steam, S5 condensed water, S6 - fresh dry Reline deep eutectic solvent, S9 - water-rich Reline deep eutectic solvent, S10 - air pipeline, S11 - circulating flash pipeline, S12 - recovery flash steam. DETAILED DESCRIPTION
[0028] The following further illustrates, but not limited to the scope of the present application, the range without departing from the purpose described above and below, the change embodiment is contained in the technical scope of the present application.
[0029] The following examples: choline chloride and urea at 80℃, 101.325kpa conditions for more than 8h, to form a colorless transparent Reline deep eutectic solvent liquid after delivery to the purification flash tank for purification, low pressure 50kpa and below, high temperature 100℃ and above flash 12h. In order to ensure continuous operation, the number of equipment can be increased according to the actual demand of the process.
[0030] Example 1:
[0031] The structure and flow diagram are shown in Figure 1 ; wherein the air drying process, air composition (oxygen 50wt%, nitrogen wt%, water 5wt%), the feed temperature is 30℃, the feed flow is 500kg / h, Reline as a gas drying agent, mass flow is 500kg / h, the packed absorption column operating pressure is 1atm, the packed absorption column operating temperature is 15℃; the flash temperature of Reline recovery flash tank is 120℃, the operating pressure is 0.1atm, the equivalent theoretical plate number of packed absorption column (T1) is 10, the feed position of wet air is the 11th (the bottom of the tower), and Reline is fed from the 1st equivalent theoretical plate. After gas-liquid phase equilibrium of multiple balance stages, the water content of dry gas collected from the top of the tower is 0.03ppm (mass fraction), and the water content in Reline is 1.8%.
[0032] Example 2:
[0033] The structure and flow diagram are shown in Figure 1The structure and flow diagram are shown in Figure 3; wherein the oxygen drying process, the oxygen composition (oxygen 99wt%, water 1wt%), the feed temperature is 25°C, the feed flow rate is 200kg / h, Reline as the gas drying agent, the mass flow rate is 200kg / h, the packed column operating pressure is 1 atm, the packed column operating temperature is 25°C; the flash temperature of Reline recovery flash tank is 120°C, the operating pressure is 0.5 atm, the equivalent theoretical plate number of packed column (T1) is 10, the wet air feed position is the 11th plate, Reline is fed from the 1st plate position of the equivalent theoretical plate. After gas-liquid phase equilibrium of multiple equilibrium stages, the water content of the dry gas collected at the top of the column is 0.09ppm (mass fraction), and the water content in Reline is 1.63%.
[0034] Example 3:
[0035] The structure and flow diagram are shown in Figure 3; wherein the oxygen drying process, the oxygen composition (oxygen 99wt%, water 1wt%), the feed temperature is 25°C, the feed flow rate is 200kg / h, Reline as the gas drying agent, the mass flow rate is 200kg / h, the packed column operating pressure is 1 atm, the packed column operating temperature is 25°C; the flash temperature of Reline recovery flash tank is 120°C, the operating pressure is 0.5 atm, the equivalent theoretical plate number of packed column (T1) is 10, the wet air feed position is the 11th plate, Reline is fed from the 1st plate position of the equivalent theoretical plate. After gas-liquid phase equilibrium of multiple equilibrium stages, the water content of the dry gas collected at the top of the column is 0.09ppm (mass fraction), and the water content in Reline is 1.63%. Figure 1 The structure and flow diagram are shown in Figure 3; wherein the oxygen drying process, the oxygen composition (oxygen 99wt%, water 1wt%), the feed temperature is 25°C, the feed flow rate is 200kg / h, Reline as the gas drying agent, the mass flow rate is 200kg / h, the packed column operating pressure is 1 atm, the packed column operating temperature is 25°C; the flash temperature of Reline recovery flash tank is 120°C, the operating pressure is 0.5 atm, the equivalent theoretical plate number of packed column (T1) is 10, the wet air feed position is the 11th plate, Reline is fed from the 1st plate position of the equivalent theoretical plate. After gas-liquid phase equilibrium of multiple equilibrium stages, the water content of the dry gas collected at the top of the column is 0.09ppm (mass fraction), and the water content in Reline is 1.63%.
Claims
1. A full-line device for drying air and air separation gases using a reline deep eutectic solvent, characterized in that, The system comprises a Reline synthesis reaction tank (B1), a Reline purification flash tank (F1), a packed absorption tower (T1), a Reline recovery flash tower (F2), a heat exchanger (E1), a heater (H1), a first condenser (C1), a second condenser (C2), and a third condenser (C3). The Reline synthesis reaction tank (B1) is provided with a choline chloride inlet (S1) and a urea inlet (S2). The bottom of the Reline synthesis reaction tank (B1) is provided with a fresh Reline deep eutectic solvent outlet (S3). The fresh Reline deep eutectic solvent outlet (S3) is connected to the feed inlet of the Reline purification flash tank (F1) through a pipeline. The upper part of the Reline purification flash tank (F1) is provided with a flash steam outlet (S4). The flash steam outlet (S4) is connected to the first condenser (C1). The corresponding condensed water outlet (S5) of the first condenser is connected to the water inlet of the heat exchanger (E1) through a pipeline. The bottom of the Reline purification flash tank (F1) is provided with a fresh dry Reline deep eutectic solvent outlet (S6). The fresh dry Reline deep eutectic solvent outlet (S6) is connected to the absorbent feed inlet of the packed absorption tower (T1) through a pipeline. The bottom of the packed absorption tower (T1) is provided with a water-rich Reline deep eutectic solvent outlet (S9). The water-rich Reline deep eutectic solvent outlet (S9) is connected to another channel inlet of the heat exchanger (E1) through a pipeline. Another channel outlet of the heat exchanger (E1) is connected to the feed inlet of the Reline recovery flash tower (F2) through a heater (H1). The bottom outlet of the Reline recovery flash tower (F2) is connected to another channel inlet of the heat exchanger (E1) through a pipeline, which can realize the cyclic dehydration of the water-rich Reline deep eutectic solvent (S9). At the same time, the bottom outlet of the Reline recovery flash tower (F2) is connected to the absorbent feed inlet of the packed absorption tower (T1) through a pipeline, which is used for recycling and reuse of the Reline deep eutectic solvent. The upper part of the Reline recovery flash tower (F2) is provided with a recovery flash steam outlet (S12). The recovery flash steam outlet (S12) is connected to the inlet of the third condenser (C3), which is used for condensing the recovery flash steam into liquid water and discharging. The packed absorption tower (T1) is provided with a wet gas inlet (S7). The inlet position is located at the lower part of the packed absorption tower (T1). The upper part of the packed absorption tower (T1) is provided with a dry gas outlet (S8). The dry gas outlet (S8) is connected to the second condenser (C2).
2. A complete line for drying air and air separation gases with Reline deep eutectic solvent according to claim 1, characterized in that, The theoretical number of tower plates N of the packed absorption tower (T1) is 5-15. The feed position of the wet gas in the packed absorption tower (T1) is the Nth plate. N is the bottom plate. The Reline feed position is the first plate at the upper part.
3. A complete line for drying air and air separation gases with Reline deep eutectic solvent according to claim 1, characterized in that, The Reline purification flash tank (F1) and the Reline recovery flash tower (F2) are provided with an atmospheric pipeline (S10) as needed.
4. The complete line for drying air and air separation gases with Reline deep eutectic solvent according to claim 1, characterized in that, Gravity drive or pump drive is adopted. Valves are designed and installed as needed during pipeline connection.
5. A complete line for drying air and air separation gases with Reline deep eutectic solvent according to claim 1, characterized in that, The line between the Reline recovery flash tower (F2) and the heat exchanger (E1) is provided with a valve, and the line between the Reline recovery flash tower (F2) and the packed absorption tower (T1) is provided with a valve.