A method for determining the solubility of disperse dyes in supercritical CO2

Abstract

The invention discloses a device and a method for measuring the solubility of disperse dyes in supercritical CO2. The device comprises a CO2 supply bottle (1), a refrigeration unit (2), a liquid tank (3), a booster pump (4), a preheater (5), a dye kettle (6), a circulation pump (7), a filter kettle (8), a hydraulic valve and an electrical control part. The CO2 supply bottle (1) stores CO2 in the liquid tank (3) through a pipeline. When the refrigeration unit (2) is in working state, the CO2 stored in the liquid tank (3) is sent to the preheater (5) through the booster pump (4) and flows into the dye kettle (6) through the pipeline. When the temperature and pressure in the dye kettle (6) reach the values ​​required by the experiment, the sixth valve (S6) is closed and the circulation pump (7) is turned on. After a certain period of time, the dye reaches a dissolution equilibrium. The ninth valve (S9) is opened to separate by reducing pressure. The dissolved dye remains in the filter kettle (8), and most of the CO2 is condensed by the refrigeration unit (2) and stored in the liquid tank (3) for recycling.

Description

Technical Field

[0001] The present invention belongs to supercritical CO 2 The technical field of fluid dyeing is particularly related to a disperse dye in supercritical CO 2 Solubility measurement device and determination method. Background Art

[0002] In supercritical state, CO 2 The fluid has a density similar to that of a liquid and a viscosity close to that of a gas, and can dissolve non-polar or weakly polar organic matter, which makes supercritical CO 2 It can replace water as dyeing medium. Supercritical CO 2 Dyeing technology based on CO 2 The dyeing process does not generate pollutants, so clean production can be achieved. The dyes used in traditional water bath dyeing are heated in supercritical CO 2 The system is no longer applicable, therefore, the determination of dye in supercritical CO 2 The solubility of disperse dyes in supercritical CO is the basis of this process. 2 There are only limited data on the solubility of dyes in the literature, and because different researchers use different dye types and solubility measurement methods, and their respective measurement conditions are limited, even for the same dye, the solubility data can vary greatly.

[0003] The existing solubility measurement methods are mainly sampling method and spectrophotometer online detection method. The sampling method is divided into static sampling method and dynamic sampling method. After reaching the dissolution equilibrium at a certain temperature and pressure, the solubility of the dye in the supercritical fluid is obtained by sampling and analysis; the spectrophotometer online detection method is to obtain the solubility of the dye in the supercritical fluid by immersing the dye in the supercritical CO 2 A visual window made of sapphire is set in the balance pipeline, and the concentration of the sample in the kettle is measured online by a spectrophotometer. The existing device for the determination of disperse dyes in supercritical fluids has the problems of complex equipment, cumbersome operation, and inaccurate measurement results, which is difficult to apply to supercritical CO 2 The dyeing process parameters provide a reliable reference.

[0004] It is very necessary to develop a method for disperse dyes in supercritical CO 2 The solubility measuring device and the matching measuring method thereof are used to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a disperse dye in supercritical CO 2 Solubility measurement device and determination method in supercritical CO at a certain temperature and pressure 2The solubility of the dispersed golden RGFL is tested in the fluid to solve the problems of complex equipment, cumbersome operation and inaccurate measurement results in the prior art.

[0006] In order to achieve the above purpose, one of the technical solutions of the present invention is: a disperse dye is prepared in supercritical CO 2 Medium solubility measurement device, mainly including CO 2 The gas cylinder (1) is composed of a refrigeration unit (2), a liquid tank (3), a booster pump (4), a preheater (5), a dye kettle (6), a circulation pump (7), a filter kettle (8), a hydraulic valve and an electrical control part. The gas cylinder (1) supplies CO through a pipeline. 2 The CO stored in the liquid tank (3) is stored in the liquid tank (3). When the refrigeration unit (2) is in the working state, the CO stored in the liquid tank (3) is 2 The dye is sent to the preheater (5) through the booster pump (4) and flows into the dye kettle (6) through the pipeline. When the temperature and pressure in the dye kettle (6) reach the values ​​required for the experiment, the valve (S6) is closed and the circulation pump (7) is turned on. After a certain period of time, the dye reaches the dissolution equilibrium, and the valve (S9) is opened to separate by reducing the pressure. The dissolved dye remains in the filter kettle (8), and most of the CO 2 After being condensed by the refrigeration unit (2), the liquid is stored in the liquid tank (3) for recycling.

[0007] In a preferred embodiment of the present invention, the CO 2 When the gas cylinder (1) is supplying gas, the first valve (S1) and the eleventh valve (S11) should be opened. A pressure gauge is installed outside the liquid tank (3). The gas supply pressure should be maintained above 4MPa. When the gas in the cylinder is insufficient, the gas cylinder should be wrapped with a heating belt (9) to accelerate the gas supply efficiency until the bottom of the gas cylinder becomes hot, and then the gas cylinder (1) should be replaced.

[0008] In a preferred embodiment of the present invention, the refrigeration unit (2) includes a refrigeration unit electrical cabinet, a water pump, and a water tower. When the second valve (S2) is opened, the water pump circulates the water in the water tower through a pipeline to the outside of the liquid tank (3), and the temperature of the refrigeration unit (2) is maintained below 7°C when it is working.

[0009] In a preferred embodiment of the present invention, before the booster pump (4) operates, it should be ensured that the third valve (S3) is opened and the refrigeration unit (2) needs to be operated in advance.

[0010] In a preferred embodiment of the present invention, the preheater (5) is designed to have a maximum temperature of 100°C, the dye kettle (6) is designed to have a maximum temperature of 150°C, a maximum pressure of 35 MPa, and a volume of 25.5 L.

[0011] In a preferred embodiment of the present invention, the dye kettle (6) is equipped with a temperature sensor (P1) and a pressure sensor (P2), the temperature error is within ±0.1°C, the pressure error is within ±0.1MPa, multiple seals are achieved at the kettle cover, and a heating plate (10) is provided in the kettle.

[0012] The whole device is equipped with a complete set of control systems and a corresponding control panel, which can display the temperature and pressure in the dye kettle (6), as well as the switches of the refrigeration unit (2), the booster pump (4), the preheater (5), and the heating plate (10) in the dye kettle. The preheater (5) and the dye kettle (6) are equipped with corresponding intelligent instruments, and the heating time and temperature of each section can be set on the intelligent instruments.

[0013] In a preferred embodiment of the present invention, the CO 2 A second one-way valve (D2) is provided between the gas cylinder (1) and the liquid tank (3), a third one-way valve (D3) is provided between the liquid tank (3) and the booster pump (4), and a first one-way valve (D1) is provided between the filter kettle (8) and the liquid tank (3). 2 It can only flow from the former to the latter; after the experiment, the excess CO 2 Recyclable and stored in tank.

[0014] In order to achieve the above purpose, the second technical solution of the present invention is a disperse dye in supercritical CO 2 The method for determining the solubility in the medium mainly includes the following steps:

[0015] Step 1: On the control panel, operate the intelligent instrument to set the heating temperature, heating time and insulation temperature and insulation time of the dye kettle (6), and set the working temperature of the preheater (5);

[0016] Step 2: Use an electronic balance to weigh the mass of the filter bag (11) and record it as M1, then add 3-7g of disperse dye and record the total mass as M2; seal the filter bag opening, put it into the dye kettle (6), and seal it with a sealing end cover and a sealing ring;

[0017] Step 3: When the preheater (5) and the dye kettle (6) reach the set temperature, open the first valve (S1), the second valve (S2), the third valve (S3), the fourth valve (S4), the sixth valve (S6), and the eleventh valve (S11), close the fifth valve (S5), the seventh valve (S7), the eighth valve (S8), and the ninth valve (S9), start the refrigeration unit (2) and the booster pump (4); remove the CO in the dye kettle (6); 2 Increase to the pressure required for the experiment;

[0018] Step 4: When the dye kettle (6) reaches the pressure required for the experiment, turn off the booster pump (4), close the sixth valve (S6), open the eighth valve (S8), and start the circulation pump (7);

[0019] Step 5: After the disperse dye reaches a dissolution equilibrium in the dye kettle (6), the circulation pump (7) is closed, the ninth valve (S9) is opened, and CO 2 The mixed fluid with disperse dye is separated by depressurization, and most of the CO 2 The recovered dye is stored in the liquid tank (3), and the dissolved dye remains in the filter kettle (8);

[0020] Step 6: When the pressure of the filter kettle (8) is equal to the pressure of the liquid tank (3), open the seventh valve (S7), close the ninth valve (S9), and drain the CO in the dye kettle (6). 2 Open the sealed end cap of the dye kettle (6), take out the filter bag, weigh it with an electronic balance and record it as M3, and calculate the solubility of the disperse dye at this temperature and pressure according to the following formula:

[0021]

[0022] Step 7: Take out the remaining dye in the filter bag (11) and rinse the bag clean. After drying, repeat steps 1 to 6 to test the solubility of the disperse dye at different temperatures and pressures.

[0023] In a preferred embodiment of the present invention, in the method, the filter bag is dense, and the dye powder can only enter and exit the filter bag by dissolving and diffusing without violently shaking the filter bag.

[0024] In a preferred embodiment of the present invention, the accuracy of the electronic balance is 0.1 mg, and it needs to be calibrated with a standard weight before each set of experiments.

[0025] The purpose of starting the circulation pump (7) is to accelerate the dissolution rate of the disperse dye. The flow rate of the circulation pump (7) is adjustable. The dissolution time of each group of experiments is 1.5 to 2.5 hours, which exceeds the time required for the disperse dye to reach dissolution equilibrium.

[0026] In a preferred embodiment of the present invention, the temperature of the dye kettle (6) set in step 1 is 80-130°C, the segmented heating time is 20-60min, the insulation time is 120min, and the preheater working temperature is 80-90°C; the experimental pressure of the dye kettle (6) in step 4 is 15-30MPa; the solubility calculated in step 6 is in g / L.

[0027] In a preferred embodiment of the present invention, the disperse dye is disperse gold RGFL, and only the effects of temperature and pressure on solubility are considered.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The dye kettle of the present invention has a large volume cavity, and under the same conditions, it can dissolve more dye than the current 1L balance kettle, and there is no need to destroy the original dissolution balance through sampling and analysis.

[0030] 2. The sampling method of the present invention needs to be connected to the back pressure regulating valve through a slender pipe, and the organic solvent collector is connected to the outlet of the back pressure regulating valve. The flow rate of the pipeline before and after the back pressure valve is unstable, and the flow rate needs to be slow enough. Dry ice is easy to form at the outlet to block the pipeline, and the dye will precipitate due to the pressure drop, affecting the solubility determination. After each experiment, the pipeline before and after the back pressure valve needs to be cleaned with a solvent, otherwise it will affect the next measurement. The volume cavity of this device is large, and the supercritical CO 2 Large amount of water does not need to pass through long and narrow pipes, and there will be no blockage at the valve.

[0031] 3. The measuring method of the present invention is simple, and the device has a wide range of measuring temperature and pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The disperse dye of the present invention is in supercritical CO 2 Schematic diagram of the device for solubility measurement.

[0033] In the figure: 1. CO 2 Gas supply bottle, 2, refrigeration unit, 3, liquid tank, 4, booster pump, 5, preheater, 6, dye kettle, 7, circulation pump, 8, filter kettle, 9, heating belt, 10, heating plate, 11, filter bag, S1, first valve, S2, second valve, S3, third valve, S4, fourth valve, S5, fifth valve, S6, sixth valve, S7, seventh valve, S8, eighth valve, S9, ninth valve, S10, tenth valve, S11, eleventh valve, D1 first check valve, D2, second check valve, D3, third check valve, F1, first pressure gauge, F2, second pressure gauge, F3, third pressure gauge, F4, fourth pressure gauge, P1, temperature sensor, P2, pressure sensor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0035] Example 1

[0036] A disperse dye solubility determination device, such as Figure 1 The specific examples shown include CO 2Gas supply cylinder (1), refrigeration unit (2), liquid tank (3), booster pump (4), preheater (5), dye kettle (6), circulation pump (7), filter kettle (8), as well as hydraulic valves and electrical control parts. The gas cylinder (1) transfers CO through the pipeline. 2 The CO stored in the liquid tank (3) is stored in the liquid tank (3). When the refrigeration unit (2) is in the working state, the CO stored in the liquid tank (3) is 2 The dye is sent to the preheater (5) through the booster pump (4) and flows into the dye kettle (6) through the pipeline. When the temperature and pressure in the dye kettle (6) reach the values ​​required for the experiment, the sixth valve (S6) is closed and the circulation pump (4) is turned on. After a certain period of time, the dye reaches the dissolution equilibrium, and the ninth valve (S9) is opened to separate by reducing the pressure. The dissolved dye remains in the filter kettle (8), and most of the CO 2 After being condensed by the refrigeration unit (2), the liquid is stored in the liquid tank (3) for recycling.

[0037] A method for using a disperse dye solubility measuring device comprises the following steps:

[0038] Step 1: On the control panel, operate the intelligent instrument to set the heating temperature, heating time, insulation temperature and insulation time of the dye kettle (6). The heating temperature of the dye kettle (6) is set to 120°C, and the temperature is increased to 120°C in three stages. The temperature of the first stage is 80°C, and the heating time is 40 minutes. The temperature of the second stage is 100°C, and the heating time is 30 minutes. The temperature of the third stage is 120°C, and the heating time is 30 minutes. The insulation temperature is 120°C, and the insulation time is 10 hours. Set the working temperature of the preheater (5) to 90°C.

[0039] Step 2: Use an electronic balance to weigh the mass of the filter bag (11) and record it as M1, then add the disperse dye and record the total mass as M2; seal the filter bag opening, put it into the dye kettle (6), and seal it with a sealing end cover and a sealing ring.

[0040] Step 3: When the preheater (5) and the dye kettle (6) reach the set temperature, open the first valve (S1), the second valve (S2), the third valve (S3), the fourth valve (S4), the sixth valve (S6), and the eleventh valve (S11), close the fifth valve (S5), the seventh valve (S7), the eighth valve (S8), and the ninth valve (S9), start the refrigeration unit (2) and the booster pump (4); remove the CO in the dye kettle (6); 2 Increase to the pressure required for the experiment.

[0041] Step 4: When the dye kettle (6) reaches the pressure required for the experiment, turn off the booster pump (4), close the sixth valve (S6), open the eighth valve (S8), and start the circulation pump (7).

[0042] Step 5: After the disperse dye reaches a dissolution equilibrium in the dye kettle (6), the circulation pump (7) is closed, the ninth valve (S9) is opened, and CO 2 The mixed fluid with disperse dye is separated by depressurization, and most of the CO 2 The recovered dye is stored in the liquid tank (3), and the dissolved dye remains in the filter kettle (8).

[0043] Step 6: When the pressure in the filter kettle (8) is equal to the pressure in the liquid tank (3), open the seventh valve (S7), close the valve (S9), and drain the CO in the dye kettle (6). 2 Open the sealed end cap of the dye kettle (6), take out the filter bag (11), weigh its mass with an electronic balance and record it as M3, and calculate the solubility of the disperse dye at this temperature and pressure according to the following formula:

[0044]

[0045] Step 7: Take out the remaining dye in the filter bag (11) and rinse the bag. After drying, repeat steps 1 to 6 to test the dispersion dye golden yellow RGFL in supercritical CO at 120°C under 6 different pressures. 2 The solubility in the medium is shown in Table 1.

[0046] Table 1 Dispersion of golden RGFL in supercritical CO 2 Medium solubility test results

[0047]

[0048] The above embodiments are merely optimized implementation methods of the present invention, which are used to illustrate the principles and effects of the present invention, but are not used to limit the present invention. It should be noted that any person skilled in the art may modify the above embodiments without violating the spirit and scope of the present invention, and such modifications shall also be regarded as the protection scope of the present invention.

Claims

1. A method for determining the solubility of disperse dyes in supercritical CO2, characterized in that: Based on the following measuring device: comprising a CO2 supply bottle (1), a refrigeration unit (2), a liquid tank (3), a booster pump (4), a preheater (5), a dye kettle (6), a circulation pump (7), a filter kettle (8), as well as a hydraulic valve and an electrical control part; the CO2 supply bottle (1) stores CO2 in the liquid tank (3) through a pipeline, and when the refrigeration unit (2) is in working state, the CO2 stored in the liquid tank (3) is sent to the preheater (5) through the booster pump (4), and flows into the dye kettle (6) through the pipeline; when the temperature and pressure in the dye kettle (6) reach the values ​​required for the experiment, the sixth valve (S6) is closed, the circulation pump (7) is turned on, and after a certain period of time, the dye reaches a dissolved equilibrium. After balancing, the ninth valve (S9) is opened to separate the dissolved dye by reducing the pressure, and most of the CO2 is stored in the liquid tank (3) for recycling after being condensed by the refrigeration unit (2); when the CO2 supply bottle (1) in the device supplies gas, the first valve (S1) and the eleventh valve (S11) should be opened, and a first pressure gauge (F1) is installed outside the liquid tank (3). The gas supply pressure should be maintained above 4MPa. When the gas in the bottle is insufficient, the CO2 supply bottle needs to be wrapped with a heating belt (9) to accelerate the gas supply efficiency until the bottom of the gas bottle becomes hot, and the CO2 supply bottle (1) is replaced; the refrigeration unit (2) includes a refrigeration unit electrical cabinet, a water pump, and a water tower. When the second valve (S2) is opened, the water pump circulates the water in the water tower through the pipeline to the outside of the liquid tank (3), and the temperature of the refrigeration unit (2) is maintained below 7°C when the booster pump (4) is working; before the booster pump (4) works, it should be ensured that the third valve (S3) is opened, and the refrigeration unit (2) needs to be operated in advance; the preheater (5) is designed to have a maximum temperature of 100°C, the dye kettle (6) is designed to have a maximum temperature of 150°C, a maximum pressure of 35MPa, and a volume of 25.5L; the dye kettle (6) is equipped with a temperature sensor (P1) and a pressure sensor (P2), the temperature error is ±0.1°C, the pressure error is ±0.1MPa, and there is a heating plate (10) in the kettle; the device is equipped with A complete set of control systems and corresponding control panels can display the temperature and pressure in the dye kettle (6), as well as the switches of the refrigeration unit (2), the booster pump (4), the preheater (5), and the heating plate (10) in the dye kettle. The preheater (5) and the dye kettle (6) are equipped with corresponding intelligent instruments, and the heating time and temperature of each section can be set on the intelligent instruments. In the device, a one-way valve (D2) is provided between the CO2 supply bottle (1) and the liquid tank (3), a third one-way valve (D3) is provided between the liquid tank (3) and the booster pump (4), and a first one-way valve (D1) is provided between the filter kettle (8) and the liquid tank (3), so that CO2 can only flow from the former to the latter. After the experiment is over, the excess CO2 can be recovered and stored in the liquid tank. The following steps are involved: Step 1: setting the heating temperature, heating time and insulation temperature and insulation time of the dye kettle (6), and setting the working temperature of the preheater (5); Step 2: weigh the mass of the filter bag (11) and record it as M1, and the total mass after adding 3-7g of disperse dye is recorded as M2; seal the filter bag opening, put it into the dye kettle (6), and seal it with a sealing end cover to press the sealing ring; Step 3: When the preheater (5) and the dye kettle (6) reach the set temperature, open the first valve (S1), the second valve (S2), the third valve (S3), the fourth valve (S4), the sixth valve (S6), and the eleventh valve (S11), close the fifth valve (S5), the seventh valve (S7), the eighth valve (S8), and the ninth valve (S9), and start the refrigeration unit (2) and the booster pump (4); increase the CO2 in the dye kettle (6) to the pressure required for the experiment; Step 4: When the dye kettle (6) reaches the pressure required for the experiment, turn off the booster pump (4), close the sixth valve (S6), open the eighth valve (S8), and start the circulation pump (7); Step 5: After the disperse dye reaches a dissolution equilibrium in the dye kettle (6), the circulation pump (7) is turned off, the ninth valve (S9) is opened, the mixed fluid of CO2 and disperse dye is depressurized and separated, most of the CO2 is recovered and stored in the liquid tank (3), and the dissolved dye remains in the filter kettle (8); Step 6: When the pressure of the filter kettle (8) is equal to the pressure of the liquid tank (3), open the seventh valve (S7), close the ninth valve (S9), and exhaust the CO2 in the dye kettle (6); open the sealed end cover of the dye kettle (6), take out the filter bag and weigh its mass as M3, and calculate the solubility (g / L) of the disperse dye at this temperature and pressure according to the following formula: Step 7: Take out the remaining dye in the filter bag (11) and rinse the bag clean. After drying, repeat steps 1 to 6 to test the solubility of the disperse dye at different temperatures and pressures.

2. The method for measuring the solubility of disperse dyes in supercritical CO2 as claimed in claim 1, characterized in that, In step 2, the filter bag is dense. Without violently shaking the filter bag, the dye powder can only enter and exit the filter bag by dissolution and diffusion. The disperse dye is dispersed golden yellow RGFL, and only the effects of temperature and pressure on solubility are considered.

3. The method for measuring the solubility of disperse dyes in supercritical CO2 as claimed in claim 1, characterized in that, The purpose of starting the circulation pump (7) in step 4 is to accelerate the dissolution rate of the disperse dye. The flow rate of the circulation pump (7) is adjustable. The dissolution time of each group of experiments is 1.5 to 2.5 hours, which exceeds the time required for the disperse dye to reach dissolution equilibrium.

4. The method for measuring the solubility of disperse dyes in supercritical CO2 as claimed in claim 1, characterized in that, The temperature of the dye kettle (6) set in step 1 is 80-130°C, the segmented heating time is 20-60min, the insulation time is 100-140min, and the preheater working temperature is 80-90°C; the experimental pressure of the dye kettle (6) in step 4 is 15-30MPa.

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