Detection Method and Detection Equipment for Adsorption Efficiency of Solid Materials to Specific Gases

Abstract

The present invention relates to the technical field of inspection and testing, and particularly to a detection method and detection equipment for the adsorption efficiency of solid materials to specific gases. It includes measuring the time when the concentration reaches a stable value when a specific gas passes through an empty experimental channel, purging the experimental channel, measuring the time when the concentration reaches a stable value when a specific gas passes through the experimental channel filled with the material to be detected, and calculating the adsorption efficiency of the material to be detected to the specific gas by using the times when the two gas concentrations reach stable values. The detection results are accurate, highly adaptable, and easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of inspection and testing, and particularly relates to a detection method and detection equipment for the adsorption efficiency of solid materials to specific gases. Background Art

[0002] The phenomenon that gas or vapor is captured by the solid surface and adheres to the surface, forming a monolayer or multi-layer gas molecular layer, is called adsorption. The adsorption efficiency usually refers to the adsorption capacity of an adsorbent for a certain substance under certain conditions. It is an important index to measure the adsorption effect. During the adsorption process, target molecules or compounds interact with the active sites on the material surface, and thus are rapidly adsorbed and fixed on the material surface. By calculating the adsorption efficiency of the adsorption material, the different adsorption capacities of different adsorption materials can be judged, which has practical significance for environmental protection, industrial production and scientific research. The adsorption efficiency can be measured by indicators such as adsorption amount, adsorption rate or adsorption percentage. Chinese Patent 2008101276992 discloses "Sample Placement Device for Detecting Adsorptive Filter Materials for Trace Pollutant Gases", and the authorization announcement number is CN101625295B. This sample placement device can provide the necessary performance data (temperature, dew point, pressure, concentration, etc.) for the adsorption efficacy of the filter material to be tested for specific gases. However, this device cannot detect and provide the technical parameters of the adsorption performance of the filter material to specific gases. Another Chinese patent application 2023105595775 discloses "A Measurement Method for Gas Adsorption Based on an Applied Electric Field", and the application publication number is CN116593534A. This measurement method coats a gas-sensitive material on an acrylic plate, places the acrylic plate between two flat electrodes, adjusts the distance between the two flat electrodes through a micrometer and a cylinder, thereby adjusting the surrounding electric field, measures the resistance of the gas-sensitive material after introducing the gas, and measures the gas adsorption performance of the gas-sensitive material according to the change of the resistance value. This method has relatively high process requirements for the flat electrodes and the electrode distance adjustment mechanism, and the process error of the electrodes has a great influence on the detection results. Its practicability is limited to a certain extent. Summary of the Invention

[0003] Aiming at the above technical problems, the purpose of the present invention is to provide a detection method and detection equipment for the adsorption efficiency of solid materials to specific gases with accurate detection results, strong adaptability and convenient operation.

[0004] The detection method for the adsorption efficiency of the solid material to specific gases according to the present invention includes the following steps:

[0005] Step 1: Introduce a specific gas into the experimental channel with an empty experimental cavity, allowing the specific gas to enter from the input port of the experimental channel and exit from the output port. Detect the change in the concentration of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value. Record the time t1 from the start of introducing the specific gas until the concentration of the specific gas at the output port reaches a stable value.

[0006] Step 2: Purge the experimental channel with high-purity nitrogen until the detected concentration of the specific gas at the output port is 0.

[0007] Step 3: Fill the experimental cavity with the material to be detected and record the weight m of the material to be detected. xf , introduce a specific gas with a fixed flow rate into the experimental channel of the experimental cavity with the material to be detected. Record the gas flow rate V1 at the input port and the inlet concentration I0. Detect the change in the concentration of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value. Record the stable gas concentration value I. t And record the time t2 from the start of introducing the specific gas until the concentration of the specific gas at the output port reaches a stable value, and the gas flow rate V2 at the output port.

[0008] Obtain the adsorption efficiency of the material to be detected for the specific gas through the following calculation formula:

[0009] m = (t2 - t1) / t2

[0010] Where m is the adsorption efficiency, t1 is the time when the concentration of the specific gas reaches a stable value at the output port of the empty experimental channel, and t2 is the time when the concentration of the specific gas reaches a stable value at the output port of the experimental channel filled with the material to be detected.

[0011] Step 4: Take out the material to be detected in the experimental cavity, seal the material to be detected, release the specific gas adsorbed on the material to be detected through thermal desorption and perform precise measurement to obtain the total amount a1 of the specific gas actually adsorbed by the material to be detected. Verify the adsorption efficiency of the material to be detected for the specific gas through the following calculation formula:

[0012]

[0013] Where a0 is the total amount of adsorbed specific gas calculated through the following formula:

[0014]

[0015] Where: a0 is the calculated total adsorption amount, with the unit of mg·g. -1 ;

[0016] V1 is the gas flow rate at the input port, with the unit of m. 3 ·min-1 ;

[0017] V2 is the gas flow rate at the output port, with the unit of m 3 ·min -1 ;

[0018] m xf is the weight of the material to be detected, with the unit of g;

[0019] I0 is the inlet concentration of the specific gas, with the unit of mg·m -3 ;

[0020] t f is the adsorption time, t f = t2 - t1, with the unit of min;

[0021] I t is the gas concentration value when the concentration of the specific gas at the output port reaches a stable value, with the unit of mg·m -3 .

[0022] Through this solution, it is only necessary to detect the time when the specific gas reaches a stable value at the output port of the experimental cavity and the change in gas concentration to calculate the adsorption efficiency of the adsorption material for this gas, and the thermal desorption method is used to verify the accuracy of the numerical value. The detection results are accurate, have strong adaptability, and are easy to operate.

[0023] Preferably, in steps one to three, the experimental cavity is in a set constant temperature state.

[0024] Through this solution, the influence of environmental temperature on the detection results can be reduced.

[0025] Preferably, the method for detecting the change in the concentration of the specific gas at the output port of the experimental channel is as follows: use a solution to absorb the specific gas discharged from the output port of the experimental channel, and calculate the concentration of the specific gas in the solution through a fluorescence reaction at regular intervals.

[0026] Through this solution, the change in gas concentration at the output port can be detected.

[0027] Preferably, detecting the change in the concentration of the specific gas at the output port of the experimental channel is to use a detection instrument for the specific gas to detect the gas concentration at the output port.

[0028] Through this solution, the change in gas concentration at the output port can be detected.

[0029] Preferably, the experimental cavity is cylindrical, and asbestos materials are filled at both ends of the part where the material to be detected is filled in the experimental cavity.

[0030] Through this solution, the asbestos material can reduce the impact of the air flow on the adsorption material and improve the accuracy of the detection results.

[0031] Preferably, the specific gas is benzene or toluene, and the material to be detected is graphene, activated carbon or silica.

[0032] With this solution, the accuracy of the detection result is higher.

[0033] The detection device for the gas adsorption capacity detection method of a material according to the present invention includes an experimental channel with an input port and an output port. An experimental cavity for filling the material to be detected is arranged in the experimental channel. Asbestos materials are filled at both ends of the position where the material to be detected is filled in the experimental cavity; an input gas flowmeter is arranged on the input port, and an output gas flowmeter and an output gas concentration detection device are arranged on the output port.

[0034] With this solution, the gas flow rate and gas concentration at the output port of the experimental channel can be accurately detected.

[0035] Preferably, a temperature control device is arranged on the experimental cavity.

[0036] With this solution, the influence of the ambient temperature on the detection result can be reduced.

[0037] Preferably, the output gas concentration detection device is a gas concentration detector.

[0038] With this solution, the change in the gas concentration at the output port can be detected.

[0039] Preferably, the output gas concentration detection device is a solvent absorption device for absorbing the gas discharged from the output port.

[0040] With this solution, the change in the gas concentration at the output port can be detected.

[0041] Due to the adoption of the above technical solution, the present invention can calculate the adsorption efficiency of the adsorption material for this gas by detecting the time when the specific gas reaches a stable value at the output port of the experimental cavity and the change in the gas concentration, and uses the thermal desorption method to verify the accuracy of the value. The detection result is accurate, has strong adaptability and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 It is a schematic structural diagram of an embodiment of the detection device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0044] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in this patent, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of this patent.

[0045] The various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0046] The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims, and drawings of the present invention are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0047] As Figure 1 shown, the detection device for the adsorption efficiency of the solid material of the present invention to a specific gas includes an experimental channel 3 with an input port 1 and an output port 2. The experimental channel 3 is a circular tubular structure, and its two ends are respectively connected to an input end cover 11 and an output end cover 12 by threads. The input port 1 is provided on the input end cover 11, and the output port 2 is provided on the output end cover 12. An experimental cavity for filling the material to be detected is arranged in the experimental channel 3. The experimental cavity is a cylindrical cavity located in the inner cavity of the experimental channel 3. Asbestos materials are filled at both ends of the place where the material to be detected is filled in the experimental cavity; an input gas flowmeter 4 is provided on the input port 1, and the input gas flowmeter 4 is used to detect the gas flow rate entering the experimental channel 3 through the input port 1; an output gas flowmeter 5 and an output gas concentration detection device 6 are provided on the output port 2. The output gas flowmeter 5 is used to detect the gas flow rate discharged from the output port 2 of the experimental channel 3, and the output gas concentration detection device 6 is used to detect the concentration of the gas discharged from the output port 2.

[0048] In addition, in order to reduce the influence of the ambient temperature on the detection data, a constant temperature device is provided on the experimental cavity. The constant temperature device can adopt various existing temperature adjustment devices such as water bath heating or thermal radiation heating.

[0049] The output gas concentration detection device 6 can be a gas concentration detector for the gas to be detected, or a solvent absorption device for absorbing the gas discharged from the output port. The gas discharged from the output port 2 of the experimental channel 3 is introduced into this absorption device, and the concentration of the gas discharged from the output port 2 is detected through the fluorescence reaction of the solvent after absorbing the gas.

[0050] The method for detecting the adsorption efficiency of the solid material for a specific gas in the present invention uses the above detection equipment and includes the following steps:

[0051] Step 1: Introduce a specific gas into the experimental channel with an empty experimental cavity, so that the specific gas enters from the input port of the experimental channel and exits from the output port. Detect the concentration change of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value, and record the time t1 from the start of introducing the specific gas to when the concentration of the specific gas at the output port reaches a stable value.

[0052] Step 2: Before the formal detection, purge the experimental channel with 99.999% high-purity nitrogen until the concentration of the specific gas detected at the output port is 0.

[0053] Step 3: After the purging is completed, fill the experimental cavity with the material to be detected, and record the weight m of the material to be detected. xf , introduce a specific gas with a fixed flow rate into the experimental channel of the experimental cavity with the material to be detected, record the gas flow rate V1 at the input port and the inlet concentration I0, detect the concentration change of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value, and record the stable gas concentration value I. t And the time t2 from the start of introducing the specific gas to when the concentration of the specific gas at the output port reaches a stable value, and the gas flow rate V2 at the output port.

[0054] The detection of the concentration change of the specific gas at the output port of the experimental channel can be carried out by the following two methods:

[0055] One is to use a solution to absorb the specific gas discharged from the output port of the experimental channel, and calculate the concentration of the specific gas in the solution through a fluorescence reaction at regular intervals. When the difference in the concentration data of the specific gas detected continuously several times is less than a specific threshold, it can be considered that the concentration of the specific gas has reached a stable value.

[0056] Another method is to set a detection instrument for the specific gas at the output port of the experimental channel, use the detection instrument to detect the gas concentration at the output port, and when the change range of the gas concentration displayed by the detection instrument is less than a specific threshold within a certain time period, it can be considered that the concentration of the specific gas has reached a stable value.

[0057] After the specific gas concentration at the outlet to be measured reaches a stable value, the adsorption efficiency of the material to be detected for the specific gas is obtained through the following calculation formula;

[0058] m = (t2 - t1) / t2

[0059] Where m is the adsorption efficiency, t1 is the time when the specific gas concentration reaches a stable value at the outlet of the empty experimental channel, and t2 is the time when the specific gas concentration reaches a stable value at the outlet of the experimental channel filled with the material to be detected.

[0060] As a further improvement of the present invention, in Step 1 and Step 3, the experimental cavity is in a set constant temperature state.

[0061] As a specific embodiment of the present invention, the specific gas is selected as benzene or toluene, and the material to be detected is selected as graphene, activated carbon or silica. Each combination is tested three times with three different concentrations of the specific gas, and the test data are shown in Table 1 below:

[0062]

[0063]

[0064] It can be seen from the above tests that the adsorption capacity of the material for the specific gas has little relation with the concentration of the specific gas. As long as the adsorption time is sufficient, the final adsorption capacity data are basically the same.

[0065] As a comparative experiment, after completing the above embodiments, the material to be detected in the experimental cavity is taken out, the material to be detected is sealed, and the specific gas adsorbed in the material to be detected is released by thermal desorption and precisely measured to obtain the total amount a1 of the specific gas actually adsorbed by the material to be detected; the adsorption efficiency of the material to be detected for the specific gas is verified through the following calculation formula

[0066]

[0067] The adsorption capacity a0 of the material to be detected for the specific gas is obtained through the following calculation formula

[0068]

[0069] Where: a0 is the adsorption capacity, with the unit of mg·g -1 ;

[0070] V1 is the gas flow rate at the inlet, with the unit of m 3 ·min -1 ;

[0071] V2 is the gas flow rate at the outlet, with the unit of m 3 ·min-1 ;

[0072] m xf is the weight of the material to be detected, with the unit of g;

[0073] I0 is the inlet concentration of the specific gas, with the unit of mg·m -3 ;

[0074] t f is the adsorption time, t f = t2 - t1, with the unit of min;

[0075] I t is the gas concentration value when the specific gas concentration at the outlet reaches a stable value, with the unit of mg·m -3 .

[0076] In this formula, V1 - V2 can obtain the flow rate of the specific gas actually entering the experimental cavity, (V1 - V2)*I0t f Multiplying the flow rate of the specific gas actually entering the experimental cavity by the adsorption time can obtain the total volume of the specific gas actually entering the experimental cavity. Multiplying the total volume of the specific gas actually entering the experimental cavity by the inlet concentration can obtain the total amount of the specific gas actually entering the experimental cavity.

[0077] Calculate the total amount of the specific gas discharged from the outlet. Subtracting the total amount of the specific gas discharged from the outlet from the total amount of the specific gas actually entering the experimental cavity can obtain the total amount of the specific gas adsorbed by the material to be detected in the experimental cavity. Dividing the total amount of the specific gas adsorbed by the material to be detected by the weight of the material to be detected can calculate the amount of the specific gas adsorbed by the material to be detected per unit weight, that is, the adsorption capacity of the material to be detected for the adsorbed specific gas.

[0078] The data obtained from the comparative experiment are shown in Table 2 below:

[0079]

[0080]

[0081] After verification by the comparative example, the error between the adsorption efficiency m obtained by the gas adsorption efficiency detection method of the material described in the present invention and the adsorption efficiency m1 measured by the thermal desorption method is extremely small. The detection result of the present invention is accurate, has strong adaptability, and is convenient to operate.

Claims

1. A method for detecting the adsorption efficiency of a solid material to a specific gas, characterized in that It includes the following steps: Step 1: Introduce a specific gas into the experimental channel with an empty experimental cavity, allowing the specific gas to enter from the input port of the experimental channel and exit from the output port. Detect the concentration change of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value, and record the time t1 from the start of introducing the specific gas to when the concentration of the specific gas at the output port reaches a stable value. Step 2: Purge the experimental channel with high-purity nitrogen until the detected concentration of the specific gas at the output port is 0. Step 3: Fill the experimental cavity with the material to be detected and record the weight of the material to be detected m xf , introduce a specific gas with a fixed flow rate into the experimental channel of the experimental cavity with the material to be detected, and record the gas flow rate at the input port V 1 and the inlet concentration I 0, detect the concentration change of the specific gas at the output port of the experimental channel until the concentration of the specific gas at the output port reaches a stable value, and record this stable gas concentration value I t and the time t2 from the start of introducing the specific gas until the concentration of the specific gas at the output port reaches a stable value, and the gas flow rate at the output port V 2; Obtain the adsorption efficiency of the material to be detected for the specific gas through the following calculation formula: where m is the adsorption efficiency, t1 is the time when the concentration of the specific gas reaches a stable value at the output port of the empty experimental channel, and t2 is the time when the concentration of the specific gas reaches a stable value at the output port of the experimental channel filled with the material to be detected. Step 4: Take out the material to be detected in the experimental cavity, seal the material to be detected, release the specific gas adsorbed in the material to be detected through thermal desorption and conduct precise measurement to obtain the total amount a1 of the specific gas actually adsorbed by the material to be detected. Verify the adsorption efficiency of the material to be detected for the specific gas through the following calculation formula where a0 is the total amount of adsorbed specific gas calculated by the following formula where: a0 is the total amount of adsorption calculated, with the unit of mg•g −1 ; V 1 is the gas flow rate at the input port, with the unit of m 3 •min −1 ; V 2 is the gas flow rate at the outlet, with the unit of m 3 •min −1 ; m xf is the weight of the material to be detected, in g; I 0 is the inlet concentration of a specific gas, with the unit of mg•m −3 ; t f is the adsorption time, t f = t2 - t1, with the unit of min; I t is the gas concentration value when the specific gas concentration at the outlet reaches a stable value, with the unit of mg•m −3 .

2. The method for detecting the adsorption efficiency of a solid material for a specific gas according to claim 1, characterized in that: In Steps 1 to 3, the experimental cavity is in a set constant temperature state.

3. The method for detecting the adsorption efficiency of a specific gas by the solid material according to claim 1 or 2, characterized in that: The method for detecting the concentration change of the specific gas at the output port of the experimental channel is as follows: Absorb the specific gas discharged from the output port of the experimental channel with a solution, and calculate the concentration of the specific gas in the solution through fluorescence reaction at regular intervals.

4. The method for detecting the adsorption efficiency of a specific gas by the solid material according to claim 1 or 2, characterized in that: Detecting the concentration change of the specific gas at the output port of the experimental channel is to use a detection instrument for the specific gas to detect the gas concentration at the output port.

5. The method for detecting the adsorption efficiency of a solid material for a specific gas according to claim 1 or 2, characterized in that: The experimental cavity is cylindrical, and asbestos materials are filled at both ends of the part where the material to be detected is filled in the experimental cavity; the specific gas is benzene or toluene, and the material to be detected is graphene or activated carbon or silica.

Images