CN108955096B - Supercritical carbon dioxide drying method - Google Patents
Supercritical carbon dioxide drying method Download PDFInfo
- Publication number
- CN108955096B CN108955096B CN201810495462.3A CN201810495462A CN108955096B CN 108955096 B CN108955096 B CN 108955096B CN 201810495462 A CN201810495462 A CN 201810495462A CN 108955096 B CN108955096 B CN 108955096B
- Authority
- CN
- China
- Prior art keywords
- drying
- carbon dioxide
- kettle
- supercritical
- fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B5/00—Drying solid materials or objects by processes not involving the application of heat
- F26B5/005—Drying solid materials or objects by processes not involving the application of heat by dipping them into or mixing them with a chemical liquid, e.g. organic; chemical, e.g. organic, dewatering aids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/06—Controlling, e.g. regulating, parameters of gas supply
- F26B21/10—Temperature; Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/14—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects using gases or vapours other than air or steam, e.g. inert gases
Abstract
The invention relates to a supercritical carbon dioxide drying method. The method comprises the following steps: (1) the temperature in the drying kettle is controlled to be 5-20 ℃; (2) placing a sample to be dried containing a solvent at a bottom position and/or a middle position in the drying kettle in the height direction of the drying kettle; and (3) introducing a carbon dioxide fluid for supercritical drying into the drying kettle to perform supercritical drying on the sample to be dried, and then discharging the carbon dioxide fluid containing the solvent generated by performing supercritical drying. The method has high drying efficiency, can effectively ensure the integrity of the product and the stability of the performance of the product, and is suitable for preparing aerogel and other porous materials in large-scale production.
Description
Technical Field
The invention relates to the technical field of supercritical drying, in particular to a supercritical carbon dioxide drying method.
Background
Supercritical drying technology (SCD), can be defined simply as the process of removing solid materials or liquids in aqueous suspension (typically water or organic solvents after water displacement) with supercritical fluids. In the conventional drying method, the existence of gas-liquid surface tension enables the pore channel of the material with the pore structure to easily collapse in the drying process, and a high-performance product cannot be obtained. The supercritical drying technology is that the drying medium is heated and pressurized to be above the critical condition, the gas-liquid interface disappears, and the surface tension is almost zero, so that the integrity of the pore channel structure can be well protected in the drying process.
The supercritical drying may be classified into supercritical organic solvent drying (SCOD), supercritical gas drying (SCGD), supercritical mixed solvent drying (SCMD), supercritical extraction-drying (SCGED) and supercritical spray drying (SASD) according to the supercritical solvent used in the drying process. At present, the supercritical gas drying process is to place a sample to be dried, which is obtained by solvent replacement, in a liquid carbon dioxide (CO) filling chamber2) The liquid carbon dioxide is used for sufficiently replacing the solvent in the sample after a period of time, then the temperature and the pressure are adjusted until the critical point of the carbon dioxide is higher, and after a period of time, the pressure is slowly reduced to the normal pressure to obtain a dry product. The supercritical gas drying process is relatively practical due to mild operating conditions, and the supercritical gas drying technology is the main drying method for preparing aerogel materials at present.
However, the existing supercritical carbon dioxide drying technology is generally only suitable for the supercritical carbon dioxide drying equipment in laboratories and small-sized kettles, and the small supercritical carbon dioxide drying technology cannot be directly used for the supercritical carbon dioxide drying of large-caliber and large kettles. Along with social development, the demand for large-size and special-shaped aerogel materials is gradually urgent, and the small supercritical drying equipment and technology cannot meet the actual demand.
CN102491326B discloses an apparatus for supercritical fluid drying and a method for preparing aerogel materials, the apparatus disclosed in this patent and the method for preparing aerogel by supercritical drying using the apparatus can realize the preparation of aerogel materials with different production scales and different production modes, the apparatus in this patent can produce aerogel materials with different sizes, profiles and different types; however, the supercritical drying by the device and the method in the patent still has the problems that the drying time is long, the drying efficiency is required to be further improved, the product is likely to crack in the large-scale production process, and the stability of the product performance is required to be improved.
Disclosure of Invention
The invention aims to provide a supercritical carbon dioxide drying method which has high drying efficiency, can effectively ensure the integrity of products and the stability of product performance and is suitable for being applied to large-scale production so as to at least solve one technical problem in the prior art.
In order to achieve the above object, the present invention provides a method for drying supercritical carbon dioxide, comprising the steps of:
(1) the temperature in the drying kettle is controlled to be 5-20 ℃;
(2) placing a sample to be dried containing a solvent at a bottom position and/or a middle position in the drying kettle in the height direction of the drying kettle; and
(3) and (3) introducing a carbon dioxide fluid for supercritical drying into the drying kettle to perform supercritical drying on the sample to be dried, and then discharging the carbon dioxide fluid containing the solvent generated by the supercritical drying.
Preferably, before the supercritical drying, the pressure in the drying kettle is adjusted to 10-15 MPa.
Preferably, after the pressure in the drying kettle is adjusted to 10-15 MPa, the temperature in the drying kettle is further adjusted to 35-45 ℃.
Preferably, after the supercritical drying is performed under the conditions that the pressure is 10 to 15MPa and the temperature is 35 to 45 ℃ for 10 to 20min, the carbon dioxide fluid containing the solvent is discharged.
Preferably, the flow rate of the carbon dioxide fluid for supercritical drying entering the drying kettle is 1500-2500L/h.
Preferably, the volume of the drying kettle is 1000-3500L.
Preferably, a partition board for placing the sample to be dried is arranged at the bottom position and/or the middle position in the drying kettle; the partition plate has a fluid through-hole for passing the carbon dioxide fluid therethrough, and different spaces partitioned by the partition plate in the drying kettle are in fluid communication with each other through the fluid through-hole.
Preferably, the method further includes the step of separating the discharged carbon dioxide fluid to separate a solvent contained in the carbon dioxide fluid, and then discharging the separated carbon dioxide fluid.
Preferably, the method further comprises the step of returning the carbon dioxide fluid discharged after separation to be used as a carbon dioxide fluid for supercritical drying.
Preferably, the pressure of the separation is 3.5-7.5 MPa, and/or the temperature of the separation is 20-35 ℃.
Compared with the prior art, the invention at least has the following beneficial effects:
(1) according to the method, the temperature in the drying kettle is controlled to be 5-20 ℃, and then the sample to be dried is placed at the bottom position and/or the middle position in the drying kettle, so that the integrity and performance stability of the product obtained after drying can be greatly guaranteed.
(2) In some preferred embodiments of the present invention, the parameters of the supercritical carbon dioxide drying process are controlled, so that the drying efficiency of the supercritical carbon dioxide drying process can be greatly improved, and the drying time can be shortened.
(3) The method can realize large-scale production of various aerogels and other porous materials, and the supercritical drying is carried out by adopting the method, so that the drying efficiency is high, the separation efficiency is high, and the recovery efficiency of the carbon dioxide fluid is high.
Drawings
Fig. 1 is a schematic diagram of an apparatus for supercritical carbon dioxide drying in some embodiments of the present invention.
FIG. 2 is a schematic cross-sectional view of the interior of the drying vessel of FIG. 1.
FIG. 3 is a schematic cross-sectional view of the interior of a drying vessel in accordance with further embodiments of the invention.
In the figure: 1: a carbon dioxide storage tank; 2: a refrigerator; 3: a high pressure metering pump; 4: drying the kettle; 5: a first separation kettle; 6: a second separation kettle; 7: a filter; 8: a condenser; 9: a partition plate; 10: a first preheater; 11: a second preheater; 12: a third preheater; 13: an outlet of the drying kettle; 14: the sample is allowed to dry.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The invention provides a supercritical carbon dioxide drying method, which comprises the following steps:
(1) the temperature in the drying kettle is controlled to be 5-20 ℃ (for example, 5 ℃, 8 ℃, 10 ℃, 12 ℃, 15 ℃, 18 ℃ or 20 ℃);
(2) placing a sample to be dried (e.g., a wet gel) containing a solvent at a bottom position and/or a middle position within the drying pot in a height direction of the drying pot; and
(3) and (3) introducing a carbon dioxide fluid for supercritical drying into the drying kettle to perform supercritical drying on the sample to be dried, and then discharging the carbon dioxide fluid containing the solvent generated by the supercritical drying.
Particularly, in the step (1), the temperature in the drying kettle is 5-20 ℃, namely, the temperature of the kettle body of the drying kettle when the sample to be dried is fed (the temperature of the kettle body when the sample is fed) is 5-20 ℃; in the present invention, the position near the bottom and the position near the middle in the drying kettle in the height direction of the drying kettle are also referred to as the bottom position and the middle position, respectively.
The supercritical drying technology in the large-scale production process is focused on the research of parameters in the supercritical drying process at present, and the supercritical drying technology and other related operations are relatively random, so that the cracking phenomenon of a product obtained after drying can be caused in the large-scale production. The invention has the advantages that the reasonable temperature of the kettle body during feeding and the reasonable placement position of the sample to be dried in the drying kettle are ensured, so that the cracking phenomenon of the obtained product can be avoided, and the integrity of the product obtained after drying and the stability of the performance of the product can be effectively ensured.
According to some preferred embodiments, the pressure in the drying vessel is adjusted to 10 to 15MPa (e.g., 10, 11, 12, 13, 14, or 15MPa) before the supercritical drying is performed.
According to some preferred embodiments, after the pressure in the drying vessel is adjusted to 10 to 15MPa, the temperature in the drying vessel is further adjusted to 35 to 45 ℃ (e.g., 35 ℃, 36 ℃, 37 ℃, 38 ℃, 39 ℃, 40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃, or 45 ℃).
According to some preferred embodiments, the supercritical drying is performed under a pressure of 10 to 15MPa and a temperature of 35 to 45 ℃ for 10 to 20min (holding time) (e.g., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20min), preferably 15min, and then the carbon dioxide fluid containing the solvent is discharged. In the invention, the time for heat preservation and pressure maintaining is preferably shortened to 10-20 min, and compared with the heat preservation and pressure maintaining for a longer time, the method can ensure the effective dissolution rate of the carbon dioxide fluid to the solvent, and improves the drying efficiency to a certain extent.
The invention optimizes the pressure and temperature and the time of heat preservation and pressure maintaining in the supercritical carbon dioxide drying process, greatly improves the drying efficiency of the supercritical carbon dioxide drying and shortens the drying time.
According to some preferred embodiments, the flow rate of the supercritical drying carbon dioxide fluid into the drying kettle is 1500-2500L/h (for example 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400 or 2500L/h). In the invention, the flow rate of the carbon dioxide fluid for supercritical drying is preferably 1500-2500L/h, and compared with the conventional supercritical drying process in which the flow rate is generally controlled to be below 1000L/h in order to avoid excessive consumption of the carbon dioxide fluid, the supercritical drying method has the advantages that the drying efficiency can be obviously improved and the drying time can be shortened by optimizing the flow rate of the carbon dioxide fluid, so that the consumption of the carbon dioxide fluid is reduced to a great extent, and the cost of the supercritical drying is saved.
According to some preferred embodiments, the drying vessel has a volume of 1000 to 3500L (e.g., 1000, 1500, 2000, 2500, 3000 or 3500L). The drying kettle is preferably a large-caliber large kettle body with the volume of 1000-3500L, and is suitable for large-scale production of various porous materials such as aerogel.
According to some specific embodiments, the supercritical carbon dioxide drying process in the present invention is: placing a certain amount of sample to be dried, which is subjected to alcohol displacement and contains a solvent, at the bottom position and/or the middle position in the height direction in a drying kettle, wherein the temperature of a kettle body of the drying kettle is 5-20 ℃ during feeding; enabling carbon dioxide fluid for supercritical drying to enter the drying kettle at a flow speed of 1500-2500L/h, adjusting the pressure in the drying kettle to be 10-15 MPa, after the pressure in the drying kettle is stable, raising the temperature in the drying kettle to 35-45 ℃, keeping the state for 15min, and enabling the carbon dioxide fluid to fully dissolve the solvent in the sample to be dried and carrying out supercritical drying on the sample to be dried; the carbon dioxide fluid containing the solvent resulting from the supercritical drying is then discharged until the solvent contained in the sample to be dried is almost completely removed. In particular, the sample can be sampled at regular time in the supercritical drying process, and the content of the solvent in the sample is detected to obtain the drying rate information.
According to some preferred embodiments, a partition board for placing the sample to be dried is arranged at the bottom position and/or the middle position in the drying kettle, as shown in fig. 3; the partition has fluid through-holes (not shown in fig. 3) for passing the carbon dioxide fluid, and the different spaces partitioned by the partition in the drying kettle are in fluid communication with each other through the fluid through-holes.
According to some preferred embodiments, a top position (near the top position) in the drying kettle may also be provided with a partition for placing the sample to be dried containing the solvent, for example as shown in fig. 2. In the present invention, for convenience of description, a partition plate disposed at a bottom position in the drying kettle in the height direction of the drying kettle may be referred to as an a partition plate, a partition plate disposed at a middle position in the drying kettle may be referred to as a B partition plate, and a partition plate disposed at a top position in the drying kettle may be referred to as a C partition plate.
According to some preferred embodiments, the method further comprises the step of separating the discharged carbon dioxide fluid to separate a solvent contained in the carbon dioxide fluid, and then discharging the separated carbon dioxide fluid.
According to some preferred embodiments, the method further comprises the step of returning the carbon dioxide fluid discharged after separation to be used as a carbon dioxide fluid for supercritical drying. In the present invention, it is preferable that the carbon dioxide fluid discharged after separation is returned to be used as the carbon dioxide fluid for supercritical drying, so that the total amount of the carbon dioxide fluid can be greatly saved while the carbon dioxide fluid for supercritical drying is continuously fed into the drying kettle and the sample to be dried in the drying kettle is continuously subjected to supercritical drying.
According to some preferred embodiments, the pressure of the separation is 3.5 to 7.5MPa (e.g. 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7 or 7.5MPa) and/or the temperature of the separation is 20 to 35 ℃ (e.g. 20 ℃, 22 ℃, 25 ℃, 28 ℃, 30 ℃, 32 ℃ or 35 ℃). In the invention, the separation pressure is preferably controlled to be 3.5-7.5 MPa, and/or the separation temperature is controlled to be 20-35 ℃, so that the separation efficiency of the solvent contained in the discharged carbon dioxide fluid and the recovery efficiency of the separated discharged carbon dioxide fluid can be effectively ensured.
According to some specific embodiments, the method of supercritical carbon dioxide drying according to the present invention is performed by an apparatus for supercritical carbon dioxide drying, and fig. 1 is a schematic view of an apparatus for supercritical carbon dioxide drying according to some embodiments of the present invention. The apparatus for supercritical carbon dioxide drying includes: a carbon dioxide storage tank 1 for storing a carbon dioxide fluid for supercritical drying; a refrigerator 2 in fluid communication with the carbon dioxide storage tank; a drying vessel 4 in fluid communication with the refrigerator 2; a high-pressure metering pump 3 for quantitatively feeding carbon dioxide fluid into the drying kettle 4 is arranged on a passage for fluid communication between the refrigerating machine 2 and the drying kettle 4; two separation vessels (a first separation vessel 5 and a second separation vessel 6) in fluid communication with the drying vessel 4; a filter 7 in fluid communication with the second separation vessel 6; a condenser 8 in fluid communication with the filter 7; the filter 7 is also in direct fluid communication with the carbon dioxide storage tank 1 and the condenser 8 is also in direct fluid communication with the carbon dioxide storage tank 1. The schematic cross-sectional view of the inside of the drying kettle 4 can be, for example, as shown in fig. 2, wherein a partition 9 for placing the sample to be dried containing the solvent is provided at a bottom position, a middle position and a top position in the drying kettle 4 in the height direction of the drying kettle 4, the partition 9 has a fluid through hole (not shown in fig. 2) for passing the carbon dioxide fluid, and different spaces partitioned by the partition 9 in the drying kettle 4 are in fluid communication with each other through the fluid through hole. The first separation vessel 5 and the second separation vessel 6 are in fluid communication in series between the drying vessel 4 and the filter 7. The apparatus for supercritical carbon dioxide drying further comprises a first preheater 10 in fluid communication between the high pressure metering pump 3 and the drying still 4, a second preheater 11 in fluid communication between the drying still 4 and the first separation still 5, and a third preheater 12 in fluid communication between the first separation still 5 and the second separation still 6. In the invention, the carbon dioxide storage tank 1, the drying kettle 4, the separation kettle 5 and the like can be regarded as pressure containers, and each pressure container can be provided with an independent pressure regulating valve for controlling the pressure intensity in each pressure container; the first preheater 10 is used for controlling the temperature in the drying kettle 4, and the second preheater 11 and the third preheater 12 are respectively used for controlling the temperature in the first separation kettle 5 and the second separation kettle 6.
In the present invention, it can be considered that a circulation path is formed between the pressure vessels, and particularly, the apparatus of the present invention may be provided with various control valves (pressure regulating valves) in the circulation path for controlling the flow of a fluid such as a carbon dioxide fluid, thereby achieving supercritical drying of the sample to be dried in the drying kettle 4 continuously by the carbon dioxide fluid through the circulation path.
In particular, the circulation mode in the circulation path in the apparatus for supercritical carbon dioxide drying is, for example: the carbon dioxide fluid is firstly refrigerated by the refrigerator 2, the low-temperature liquid carbon dioxide fluid obtained after refrigeration by the refrigerator is sent into the drying kettle 4 from the fluid inlet at the bottom in the drying kettle 4 by the pressurization effect of the high-pressure metering pump 3 by adopting the low-temperature cold feeding mode, when the pressure in the drying kettle 4 reaches the set pressure, for example, by opening control valves between the drying kettle 4 and the first separation kettle 5 and between the first separation kettle 5 and the second separation kettle 6, the carbon dioxide fluid sequentially enters the two separation kettles from the outlet of the drying kettle 4 for separation, when the pressure in the two separation kettles reaches the set separation pressure, a valve between the second separation kettle 6 and the filter 7 is opened, the carbon dioxide fluid is filtered by the filter 7 and then enters the condenser 8, and after the carbon dioxide fluid is condensed into the liquid carbon dioxide in the condenser 8, and returned to the carbon dioxide storage tank 1, thereby achieving circulation of the carbon dioxide fluid in the circulation path.
After the whole supercritical drying and separating process is finished, closing heating systems of various control valves and a preheater, emptying residual gas in the device, and opening a drying kettle cover to obtain a dried product.
In particular, in order to reduce the content of the solvent contained in the carbon dioxide fluid returned to the carbon dioxide storage tank 1 during the circulation in the circulation passage and to avoid the influence of the solvent contained in the carbon dioxide fluid for supercritical drying on the structure and performance of the product, a material capable of adsorbing the solvent (for example, a solvent or a molecular sieve, etc.) may be placed in the first separation tank 5 and the second separation tank 6.
The invention will be further illustrated by way of example, but the scope of protection is not limited to these examples.
Example 1
Supercritical carbon dioxide drying was carried out using the apparatus shown in figure 1:
putting 1000L of silicon dioxide wet gel on a clapboard A of a drying kettle with the kettle body temperature of 10 ℃ during feeding, and starting a high-pressure metering pump to enable carbon dioxide fluid for supercritical drying to enter the drying kettle at the flow rate of 1500L/h; adjusting a valve to adjust the pressure in the drying kettle to 10MPa, after the pressure is stabilized for a period of time, heating the drying kettle to 35 ℃, keeping the state for 15min (the time of heat preservation and pressure maintenance), fully dissolving the carbon dioxide fluid and the solvent (alcohol-water solvent) contained in the silica wet gel, then slowly opening a pressure reducing valve, slowly discharging the mixed fluid (carbon dioxide fluid containing the solvent) of the carbon dioxide fluid and the alcohol-water solvent, and controlling the flow rate of the carbon dioxide to be 1500L/h in the whole process. And (3) the whole drying process is continued until the solvent is almost completely removed, the valve and the heating system are closed, the gas in the device is emptied, and the drying kettle is opened to obtain the silicon dioxide aerogel.
The performance of the aerogel material obtained in the embodiment is tested, and the performance comprises the pore diameter, the specific surface area, the appearance and the like; the drying time of this example was recorded, and the results are shown in table 1.
The test method comprises the following steps:
drying time: the time required from the start of the sample being placed in the drying vessel to the time the product is removed.
Pore diameter, specific surface area: measured on a V-Sorb2800P model pore size and specific surface analyzer.
Example 2
Supercritical carbon dioxide drying was carried out using the apparatus shown in figure 1:
putting 1000L of silicon dioxide wet gel on a B clapboard of a drying kettle with the kettle body temperature of 8 ℃ during feeding, and starting a high-pressure metering pump to enable carbon dioxide fluid for supercritical drying to enter the drying kettle at the flow rate of 1500L/h; adjusting a valve to adjust the pressure in the drying kettle to 15MPa, after the pressure is stabilized for a period of time, heating the drying kettle to 35 ℃, keeping the state for 15min, fully dissolving the carbon dioxide fluid and the solvent (alcohol-water solvent) contained in the silica wet gel, then slowly opening a pressure reducing valve to slowly discharge the mixed fluid (carbon dioxide fluid containing the solvent) of the carbon dioxide fluid and the alcohol-water solvent, and controlling the flow rate of the carbon dioxide to be 1500L/h in the whole process. And (3) the whole drying process is continued until the solvent is almost completely removed, the valve and the heating system are closed, the gas in the device is emptied, and the drying kettle is opened to obtain the silicon dioxide aerogel.
The aerogel material obtained in the embodiment is subjected to performance tests by the same test method as in embodiment 1, wherein the performance tests comprise pore size, specific surface area, appearance and the like; the drying time of this example was recorded, and the results are shown in table 1.
Example 3
Supercritical carbon dioxide drying was carried out using the apparatus shown in figure 1:
putting 1000L of silicon dioxide wet gel on a clapboard A of a drying kettle with the kettle body temperature of 10 ℃ during feeding, and starting a high-pressure metering pump to enable carbon dioxide fluid for supercritical drying to enter the drying kettle at the flow rate of 2000L/h; adjusting a valve to adjust the pressure in the drying kettle to 10MPa, after the pressure is stabilized for a period of time, heating the drying kettle to 40 ℃, keeping the state for 15min, fully dissolving the carbon dioxide fluid and the solvent (alcohol-water solvent) contained in the silica wet gel, then slowly opening a pressure reducing valve, slowly discharging the mixed fluid (carbon dioxide fluid containing the solvent) of the carbon dioxide fluid and the alcohol-water solvent, and controlling the flow rate of the carbon dioxide to be 2000L/h in the whole process. And (3) the whole drying process is continued until the solvent is almost completely removed, the valve and the heating system are closed, the gas in the device is emptied, and the drying kettle is opened to obtain the silicon dioxide aerogel.
The aerogel material obtained in the embodiment is subjected to performance tests by the same test method as in embodiment 1, wherein the performance tests comprise pore size, specific surface area, appearance and the like; the drying time of this example was recorded, and the results are shown in table 1.
Example 4
Example 4 is essentially the same as example 1, except that: placing the silica wet gel on a partition board B of a drying kettle; the flow rate of the carbon dioxide fluid was 1000L/h.
Example 5
Example 5 is essentially the same as example 1, except that: adjusting a valve to adjust the pressure in the drying kettle to 20MPa, and after the pressure is stabilized for a period of time, heating the drying kettle to 50 ℃.
Example 6
Example 6 is essentially the same as example 1, except that: two 500L silica wet gels were placed on septum A and septum B of the drying kettle, respectively.
Example 7
Example 7 is essentially the same as example 1, except that: the time for heat preservation and pressure maintaining is 2 h.
Comparative example 1
Comparative example 1 is substantially the same as example 1 except that: the temperature of the kettle body during feeding is 30 ℃.
Comparative example 2
Comparative example 2 is substantially the same as example 1 except that: the silica wet gel was placed on the C septum of the drying kettle.
Comparative example 3
Comparative example 3 is substantially the same as example 1 except that: the temperature of the kettle body is 30 ℃ during feeding; adjusting a valve to adjust the pressure in the drying kettle to be 20MPa, and after the pressure is stabilized for a period of time, heating the drying kettle to 50 ℃; the flow rate of the carbon dioxide fluid was 1000L/h.
Comparative example 4
Comparative example 4 is substantially the same as example 1 except that: placing the silica wet gel on a C clapboard of a drying kettle; adjusting a valve to adjust the pressure in the drying kettle to be 20MPa, and after the pressure is stabilized for a period of time, heating the drying kettle to 50 ℃; the flow rate of the carbon dioxide fluid was 1000L/h.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method of supercritical carbon dioxide drying, characterized in that the method comprises the steps of:
(1) the temperature in the drying kettle is controlled to be 5-20 ℃;
(2) placing a sample to be dried containing a solvent at a bottom position and/or a middle position in the drying kettle in the height direction of the drying kettle; and
(3) and (3) introducing a carbon dioxide fluid for supercritical drying into the drying kettle to perform supercritical drying on the sample to be dried, and then discharging the carbon dioxide fluid containing the solvent generated by the supercritical drying.
2. The method of claim 1, wherein:
and before the supercritical drying, adjusting the pressure in the drying kettle to be 10-15 MPa.
3. The method of claim 2, wherein:
after the pressure in the drying kettle is adjusted to 10-15 MPa, the temperature in the drying kettle is further adjusted to 35-45 ℃.
4. The method of claim 3, wherein:
and (3) performing supercritical drying under the conditions that the pressure is 10-15 MPa and the temperature is 35-45 ℃ for 10-20 min, and then discharging the carbon dioxide fluid containing the solvent.
5. The method of claim 1, wherein:
the flow rate of the carbon dioxide fluid for supercritical drying entering the drying kettle is 1500-2500L/h.
6. The method of claim 1, wherein:
the volume of the drying kettle is 1000-3500L.
7. The method of claim 1, wherein:
a clapboard for placing the sample to be dried is arranged at the bottom and/or middle part in the drying kettle;
the partition plate has a fluid through-hole for passing the carbon dioxide fluid therethrough, and different spaces partitioned by the partition plate in the drying kettle are in fluid communication with each other through the fluid through-hole.
8. The method according to any one of claims 1 to 7, wherein:
the method further includes the step of separating the discharged carbon dioxide fluid to separate a solvent contained in the carbon dioxide fluid, and then discharging the separated carbon dioxide fluid.
9. The method of claim 8, wherein:
the method further comprises a step of returning the carbon dioxide fluid discharged after separation to be used as a carbon dioxide fluid for supercritical drying.
10. The method of claim 8, wherein:
the pressure of the separation is 3.5-7.5 MPa, and/or the temperature of the separation is 20-35 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810495462.3A CN108955096B (en) | 2018-05-22 | 2018-05-22 | Supercritical carbon dioxide drying method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810495462.3A CN108955096B (en) | 2018-05-22 | 2018-05-22 | Supercritical carbon dioxide drying method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108955096A CN108955096A (en) | 2018-12-07 |
| CN108955096B true CN108955096B (en) | 2020-04-17 |
Family
ID=64499538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810495462.3A Active CN108955096B (en) | 2018-05-22 | 2018-05-22 | Supercritical carbon dioxide drying method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108955096B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7083048B2 (en) * | 2018-12-13 | 2022-06-09 | エルジー・ケム・リミテッド | Supercritical drying method for silica wet gel blanket |
| CN112971125A (en) * | 2021-03-12 | 2021-06-18 | 广东普萃特医生物工程有限公司 | Method for preparing cubilose gel food by supercritical drying technology |
| CN115704647A (en) * | 2021-08-10 | 2023-02-17 | 爱彼爱和新材料有限公司 | Supercritical carbon dioxide drying device and application thereof, and supercritical carbon dioxide drying method |
| CN116393052B (en) * | 2023-03-31 | 2023-12-26 | 广东埃力生科技股份有限公司 | Aerogel product, and preparation method and preparation system thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4012194A (en) * | 1971-10-04 | 1977-03-15 | Maffei Raymond L | Extraction and cleaning processes |
| CN1382070A (en) * | 1999-10-21 | 2002-11-27 | 阿斯彭***公司 | Rapid aerogel production process |
| CN101001533A (en) * | 2004-06-16 | 2007-07-18 | 费伊肯开发与实施有限公司 | Dehydration method |
| CN102491326A (en) * | 2011-11-30 | 2012-06-13 | 航天特种材料及工艺技术研究所 | Device for drying supercritical fluid and method for preparing aerogel material |
| CN106110384A (en) * | 2016-07-27 | 2016-11-16 | 大连大学 | A kind of medicine carrying aeroge preparation method based on supercritical fluid technology |
| CN106809842A (en) * | 2015-11-30 | 2017-06-09 | 航天特种材料及工艺技术研究所 | A kind of preparation method of high temperature oxidation resisting Silica Aerogels |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000093805A (en) * | 1998-09-22 | 2000-04-04 | Kobe Steel Ltd | Regeneration of zeolite catalyst and regenerating device of catalyst |
| US7404943B2 (en) * | 2001-05-30 | 2008-07-29 | The Regents Of The University Of California | Methods for solubilizing and recovering fluorinated compounds |
| CA2696975A1 (en) * | 2006-08-18 | 2008-02-21 | Semo Milling, Llc | Power production using grain fractionation products |
-
2018
- 2018-05-22 CN CN201810495462.3A patent/CN108955096B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4012194A (en) * | 1971-10-04 | 1977-03-15 | Maffei Raymond L | Extraction and cleaning processes |
| CN1382070A (en) * | 1999-10-21 | 2002-11-27 | 阿斯彭***公司 | Rapid aerogel production process |
| CN101001533A (en) * | 2004-06-16 | 2007-07-18 | 费伊肯开发与实施有限公司 | Dehydration method |
| CN102491326A (en) * | 2011-11-30 | 2012-06-13 | 航天特种材料及工艺技术研究所 | Device for drying supercritical fluid and method for preparing aerogel material |
| CN106809842A (en) * | 2015-11-30 | 2017-06-09 | 航天特种材料及工艺技术研究所 | A kind of preparation method of high temperature oxidation resisting Silica Aerogels |
| CN106110384A (en) * | 2016-07-27 | 2016-11-16 | 大连大学 | A kind of medicine carrying aeroge preparation method based on supercritical fluid technology |
Non-Patent Citations (1)
| Title |
|---|
| CO2超临界干燥制备SiO2气凝胶及其表征;郑文芝等;《广州大学学报(自然科学版)》;20101231;第77-80页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108955096A (en) | 2018-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108955096B (en) | Supercritical carbon dioxide drying method | |
| JP4762154B2 (en) | Vacuum extraction device used for extraction of Chinese medicine | |
| US20180085684A1 (en) | Supercritical fluid extraction apparatuses and methods for operating the same | |
| CN207324143U (en) | Portable supercritical fluid extraction instrument | |
| CN109055157A (en) | A kind of energy-efficient continuous freezing and filtering system and process of health-care spirit | |
| CN105779055B (en) | A kind of natural gas mercury-removing device and method | |
| CN204513905U (en) | Oil field helps adopts tail gas recycle CO 2device | |
| CN106268191B (en) | A kind of low-temperature methanol washing tail-gas water washing device and its process | |
| CN102500128A (en) | Method and system for recovering crystal liquid in abandoned liquid crystal display | |
| CN204552724U (en) | A kind of efficient crude Treatment system being applicable to self lift type test/production platform | |
| CN204752733U (en) | Fruit wine fermentation cooling device | |
| CN102491889B (en) | Method for removing hexaldehyde and 2-heptanone in cyclohexanone | |
| CN108402461A (en) | Extract the supercritical carbon dioxide equipment of Chinese-wolfberry nutritive ingredient | |
| CN203724977U (en) | Efficient condensation separator | |
| US8034159B2 (en) | Method for removing hydrocarbons from a vapour-gas mixture and a device for carrying out said method | |
| CN205379717U (en) | Vacuum filtration processing apparatus of separation discarded object chemicals | |
| CN107308925B (en) | System and method for activating and regenerating oil gas recovery adsorbent in refinery plant | |
| CN104482728A (en) | Supercritical CO2 drying method and device for valsartan | |
| CN206858161U (en) | A kind of bromine recovery device | |
| CN202270386U (en) | Recovery system of liquid crystal in waste liquid crystal displays | |
| CN108654135B (en) | Subcritical fluid isobaric extraction separation system and process flow | |
| CN102430345B (en) | Method of preparing supporting type ionic liquid membrane by using high-pressure carbon dioxide under low temperature | |
| CN213085900U (en) | LNG decarbonization system based on MDEA solvent | |
| WO2020124659A1 (en) | Apparatus for continuously generating hydrate under action of electrostatic atomization | |
| CN106823451B (en) | Increase of CO2Charging process for supercritical extraction yield |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |