Measurement Method of Isotope Abundance in CO Gas

Abstract

Embodiments of the present application provide a method for measuring the isotopic abundance in CO gas. The measurement method includes: detecting CO gas using a mass spectrometer to obtain a detection signal value, wherein the CO gas is obtained from a target position of a target tower, the target position of the target tower including any one of the following: the bottom of a primary distillation tower, the top of a primary distillation tower, or the bottom of a secondary distillation tower; the CO gas includes all CO isotopic components; based on the operating principle of the target tower during CO gas distillation, a target CO isotopic component is screened from all CO isotopic components; the abundance value of the target CO isotopic component is determined based on the detection limit of the mass spectrometer and the natural abundance value of the target CO isotopic component; and the abundance value of the carbon isotope and the abundance value of the target CO isotope component in the CO gas are determined based on the detection signal value and the abundance value of the target CO isotope component.

Description

Technical Field

[0001] The present application relates to the field of isotope preparation technology, and in particular to a method for measuring the isotope abundance in CO gas. Background Art

[0002] Highly abundant stable isotopes 13 C is the raw material for detecting Helicobacter pylori, but 13 The natural abundance of C is only 1.1%, and it needs to be enriched to increase its abundance to 99%. The current process route suitable for industrial production is mainly to prepare high-abundance C through low-temperature distillation of CO. 13 C product. Carbon contains two stable isotopes 12 C and 13 C, oxygen has three stable isotopes 16 O. 17 O and 18 O, thus forming 12 C 16 O. 12 C 17 O. 12 C 18 O. 13 C 16 O. 13 C 17 O. 13 C 18 The cryogenic distillation process utilizes the differences in boiling points of the six molecules to concentrate the heavy components at the bottom of the distillation tower and the light components at the top.

[0003] The main method for analyzing carbon and oxygen isotopes in CO is to use isotope mass spectrometry, which is a method of separating and quantifying by the difference in molecular mass. However, only using isotope mass spectrometry is not enough to analyze the carbon and oxygen isotopes produced from cryogenic distillation CO. 13 The CO gas obtained from the distillation tower of C is separated and quantified based on the difference in molecular mass number. However, there is a problem that the isotopic abundance in the CO gas corresponding to each distillation tower cannot be calculated, which makes it impossible to monitor and adjust the distillation tower. Summary of the Invention

[0004] In view of the above problems, a method for measuring isotope abundance in CO gas and its application are provided to overcome the above problems or at least partially solve the above problems.

[0005] According to a first aspect of the embodiment of the present application, a method for measuring the isotope abundance in CO gas is provided, comprising: detecting the CO gas using a mass spectrometer to obtain a detection signal value; wherein the CO gas is produced from the distillation of CO 13The target position of the target tower in the multi-stage distillation tower of C is obtained, and the target position of the target tower includes any one of the following: the bottom of the first distillation tower, the top of the first distillation tower, and the bottom of the second distillation tower; the CO gas includes all CO isotope components; according to the working principle of the target tower when distilling CO gas, the target CO isotope component is screened from all CO isotope components; according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component, the abundance value of the target CO isotope component is determined; according to the detection signal value and the abundance value of the target CO isotope component, the abundance value of the carbon isotope and the abundance value of the oxygen isotope in the CO gas are determined.

[0006] The measurement method provided in the embodiment of the present application is to produce 13 The carbon isotope abundance value in the CO gas is obtained by mass spectrometry of the CO gas obtained at the target position of the target tower in the process C. Furthermore, the oxygen isotope abundance value in the CO gas is obtained based on the natural abundance value of the target CO isotope component determined by the target tower, the detection limit of the mass spectrometer, and the detection signal value. The measurement method provided in the embodiments of the present application solves the problem of being unable to calculate the isotope abundance in the CO gas corresponding to different positions in each tower, facilitates accurate monitoring and adjustment of the distillation tower process conditions, and thereby improves the separation efficiency of the distillation tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above contents and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings.

[0008] Figure 1 Schematic diagram of a method for measuring isotope abundance in CO gas according to one embodiment of the present application.

[0009] Figure 2 Schematic diagram of a flow chart of a method for determining the abundance value of a target CO isotope component according to one embodiment of the present application.

[0010] Figure 3 Schematic diagram of a flow chart of a method for determining the abundance value of a target CO isotope component according to another embodiment of the present application.

[0011] Figure 4 According to the embodiment of the present application, CO is produced by distillation 13 Schematic diagram of the process of C.

[0012] Figure 5 Schematic diagram of a method for measuring isotope abundance in CO gas according to another embodiment of the present application.

[0013] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0014] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of this application. Obviously, the described embodiment is only one embodiment of this application, not all embodiments. Based on the described embodiments of this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0015] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. If the full text involves descriptions such as "first" and "second", the "first" and "second" descriptions are only used to distinguish similar objects, and cannot be understood as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data described by "first" and "second" can be interchangeable under appropriate circumstances. If "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes Solution A, Solution B, or solutions that meet both A and B.

[0016] The method for analyzing carbon and oxygen isotopes in CO is mainly to use isotope mass spectrometry. Mass spectrometry is to separate and quantify by the difference in molecular mass number. However, among the six isotope molecules of CO, 12 C 17 O and 13 C 16 The mass number of O is 29. 12 C 18 O and 13 C 17 The mass number of O is 30. The current isotope mass spectrometer cannot separate the overlapping mass peaks mentioned above and cannot obtain independent 12 C 17 O. 13 C 16 O. 13 C 17 O. 12 C 18 O signal, only the signals of mass numbers 28, 29, 30, and 31 and their relative ratios can be obtained, but the ratios of the six molecules cannot be obtained. Therefore, it is difficult to determine the molecular weight of the low-temperature distillation product. 13 The carbon and oxygen isotopes in the CO gas were quantitatively analyzed during the C process.

[0017] The embodiments of the present application provide a method for measuring the isotope abundance in CO gas. Figure 1FIG. 1 is a schematic diagram of a method for measuring isotope abundance in CO gas according to an embodiment of the present application. Figure 1 As shown, the method 100 for measuring isotope abundance in CO gas includes operations S101 to S104.

[0018] In operation S101, CO gas is detected by a mass spectrometer to obtain a detection signal value. 13 The target position of the target tower in the multi-stage distillation tower of C is obtained, and the CO gas includes all CO isotope components.

[0019] In operation S102, according to the working principle of the target tower when distilling CO gas, a target CO isotope component is screened from all CO isotope components.

[0020] In operation S103 , the abundance value of the target CO isotope component is determined according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component.

[0021] In operation S104 , the abundance value of the carbon isotope in the CO gas and the abundance value of the oxygen isotope in the CO gas are determined according to the detection signal value and the abundance value of the target CO isotope component.

[0022] In this embodiment, CO is distilled to produce 13 During the C process, the CO gas enters a primary distillation tower for separation. The CO gas flowing out of the bottom of the primary distillation tower passes through a scrambler and then enters a secondary distillation tower for separation. The target tower can include a primary distillation tower or a secondary distillation tower. The target position of the target tower includes any one of the following: the bottom of the primary distillation tower, the top of the primary distillation tower, or the bottom of the secondary distillation tower. The mass spectrometer can be an isotope mass spectrometer used in conventional experiments. All CO isotope components can include: 12 C 16 O. 12 C 17 O. 12 C 18 O. 13 C 16 O. 13 C 17 O. 13 C 18 O.

[0023] In this embodiment, the target CO isotope composition can be determined based on the working principle of the target tower. In this embodiment, the natural abundance value of the target CO isotope composition can be determined based on the existing database storing the natural abundance value of CO isotopes. In this embodiment, the carbon isotopes in the CO gas can include 12 C and 13 C. Oxygen isotopes in CO gas can include 16O. 17 O and 18 O.

[0024] Specifically, when CO gas is passed into a mass spectrometer, the largest peak in the detection result is the so-called mother peak, which represents the single ionization of CO. + , these are peaks with mass numbers of 28 to 31. At the same time, CO molecules also produce C + and O + Ion fragment. C + The signals of the ions are at mass numbers 12 and 13, which can represent the overall carbon isotope composition. Therefore, by detecting the signal values ​​at mass numbers 12 and 13, we can get 12 C and 13 The abundance of C.

[0025] However, since the mass spectrometer always has a water background, which generates signals with mass numbers 16 (O), 17 (HO), and 18 (H2O), the signals with mass numbers 16, 17, and 18 cannot represent the oxygen isotope composition in CO. Therefore, it is necessary to analyze and calculate the abundance of oxygen isotopes in CO gas based on the detection signal value of the mass spectrometer.

[0026] Specifically, the main component enriched at the target position can be determined based on the working principle of the target tower, and then the target CO isotope component can be screened from all CO isotope components. The abundance value of the target CO isotope component can be determined based on the detection limit of the mass spectrometer itself and the natural abundance value of the target CO isotope component. Then, the abundance value of the target CO isotope component can be obtained by combining the detection signal values ​​at mass numbers of 12, 13, 28, 29, 30 and 31 with the abundance value of the target CO isotope component. 16 O. 17 O and 18 The abundance of O.

[0027] For example, the main component enriched at the target position of the target tower is 13 C 17 In the case of O, the target CO isotope composition can be 13 C 17 O, 13 C 17 The natural abundance of O is 0.00041%, while the detection limit of the mass spectrometer is 13 C 17 The natural abundance of O is above 0.00041%, which means that the detection limit of the mass spectrometer is above 0.00041%. 13 C 17 O component, so 13 C 17 The abundance of O component can be neglected, and we can get 13 C 17The abundance value of O is 0. Then, according to the detection signal values ​​at mass numbers 12, 13, 28, 29, 30 and 31, we can get 16 O. 17 O and 18 The abundance of O.

[0028] As described above, this embodiment obtains the carbon isotope abundance value in the CO gas by performing mass spectrometry on the CO gas obtained from the target position of the target tower, thereby obtaining the detection signal value. Furthermore, based on the operating principle of the target tower, this embodiment analyzes the possible composition of the CO gas and screens out negligible components, thereby calculating the abundance values ​​of each component in the CO gas and further determining the abundance values ​​of carbon and oxygen isotopes in the CO gas. This solves the problem of being unable to calculate the isotope abundance values ​​in the CO gas corresponding to each distillation tower, facilitates accurate monitoring and adjustment of the distillation tower process conditions, and thereby improves the distillation tower separation efficiency.

[0029] It should be noted that the embodiment of the present application can use the method for measuring the isotope abundance in CO gas, according to the different positions of the distillation tower. x C y The composition of O (x=12, 13; y=16, 17, 18) is determined, and the abundance values ​​of all CO isotope components and the abundance values ​​of oxygen isotopes and carbon isotopes in CO gas are determined.

[0030] In some embodiments, the detection signal value includes a signal value corresponding to the mass number of the CO gas and a signal value corresponding to the mass number of the carbon isotope in the CO gas. It is understood that the signal value corresponding to the mass number of the CO gas may include signal values ​​corresponding to mass numbers of 28, 29, 30, and 31. The signal value corresponding to the mass number of the carbon isotope in the CO gas may include signal values ​​corresponding to mass numbers of 12 and 13.

[0031] Figure 2 Schematic diagram of a method for determining the abundance value of a target CO isotope component according to one embodiment of the present application. Figure 2 As shown, the method 200 for determining the abundance value of the target CO isotope component may include operations S201 to S203 when determining that the signal value corresponding to the mass number of the carbon isotope in the CO gas meets the threshold.

[0032] In operation S201 , the natural abundance value of a target CO isotope component is obtained.

[0033] In operation S202 , a detection limit of the mass spectrometer is determined according to the mass spectrometer.

[0034] In operation S203 , the abundance value of the target CO isotope component is determined according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component.

[0035] In this embodiment, the threshold value can be determined based on the signal peak measured by the actual mass spectrometer. For example, in the mass spectrometer, C + The size of the fragment peak may be the same as the parent peak CO + A few percentage points, and 13 The isotope fraction of carbon is approximately 0.5%. The peak at mass number 13 may be 10,000 times smaller than the peak at mass number 28, resulting in an extremely small signal peak at mass number 13, making it difficult to accurately measure. In this case, the threshold value can be 1 / 10,000 of the signal value at mass number 28. When the signal value corresponding to the mass number of the carbon isotope in the CO gas is greater than or equal to the threshold value, the signal value corresponding to the mass number of carbon in the CO gas is determined to meet the threshold value.

[0036] In this embodiment, the natural abundance value of the target CO isotope component can be obtained from a database storing natural abundance values ​​of CO isotopes. Based on the mass spectrometer model, the detection limit of the mass spectrometer is obtained from a database storing detection information for different mass spectrometer models. Based on the detection limit of the mass spectrometer, the result of measuring the target CO isotope component is determined, thereby determining the abundance value of the target CO isotope component.

[0037] As described above, the abundance value of the target CO isotope component is obtained based on the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component. This is conducive to further combining the detection signal value to accurately determine the abundance value of the oxygen isotope in the CO gas, improve the accuracy of calculating the separation efficiency of the target tower, and help to accurately monitor and adjust the target tower.

[0038] In some embodiments, screening a target CO isotope component from all CO isotope components according to a target tower may include: analyzing components enriched at a target position of the target tower; and screening a target CO isotope component from CO isotope components with a mass number of 29 or 30 according to the analysis results.

[0039] It should be noted that the working principle of the target tower is to enrich the heavy components at the bottom of the tower and enrich the light components at the top of the tower. In this embodiment, the target position of the target tower can include any one of the following: the bottom of the first distillation tower, the top of the first distillation tower, and the bottom of the second distillation tower.

[0040] In some embodiments, the components enriched at the target position of the target tower can be analyzed. Based on the analysis results, the component with a content close to 0 at the target position is selected from the CO isotope components with a mass number of 29 or 30 as the target CO isotope component, so that the content of the target CO isotope component can be ignored, which facilitates the calculation of the abundance values ​​of the remaining CO isotope components based on the detection signal value obtained by the mass spectrometer.

[0041] The ratios of the signal values ​​of the mass spectrometer at mass numbers 12, 13, 28, 29, 30, and 31 can be expressed as

[12] ,

[13] ,

[28] ,

[29] ,

[30] , and

[31] , respectively, as shown in the following equations (1) to (6):

[0042]

[12] =I 12 / (I 12 +I 13 ) (1)

[0043]

[13] =I 13 / (I 12 +I 13 ) (2)

[0044]

[28] =I 28 / (I 28 +I 29 + I 30 +I 31 ) (3)

[0045]

[29] =I 29 / (I 28 +I 29 + I 30 +I 31 ) (4)

[0046]

[30] =I 30 / (I 28 +I 29 + I 30 +I 31 ) (5)

[0047]

[31] =I 31 / (I 28 +I 29 + I 30 +I 31 ) (6)

[0048] Among them, I 12 , I 13 , I 28 , I 29 , I 30 , I 31 They represent the signal values ​​of the mass spectrometer at mass numbers 12, 13, 28, 29, 30, and 31 respectively.

[0049] The ratios of the six molecules in CO, i.e., their abundance values, are expressed as [ 12 C 16 O]、[ 12 C 17 O]、[ 13 C 16 O]、[ 12C 18 O]、[ 13 C 17 O]、[ 13 C 18 O] indicates. It should be noted that due to 13 C 16 O. 13 C 17 O. 13 C 18 The sum of the proportions of O is 13 The abundance value of C. From the above equations (1) to (6), the following equations (7) to (11) can be obtained:

[0050] [ 12 C 16 O]=

[28] (7)

[0051] [ 13 C 18 O]=

[31] (8)

[0052] [ 12 C 17 O]+[ 13 C 16 O]=

[29] (9)

[0053] [ 12 C 18 O]+[ 13 C 17 O]=

[30] (10)

[0054] [ 13 C 16 O]+[ 13 C 17 O]+[ 13 C 18 O]=

[13] (11)

[0055] According to the above formulas (7) to (11), it is only necessary to analyze the possible composition of the CO sample according to the working principle of the distillation tower and ignore 12 C 17 O. 13 C 16 O. 12 C 18 O. 13 C 17 O one of them, the abundance of all components can be obtained.

[0056] Specifically, when the target position of the target tower is the bottom of the secondary distillation tower, the target CO isotope composition can be 12 C 17When screening the target CO isotope, the possible compositions of the various CO isotope components at the bottom of the secondary distillation tower are analyzed to determine the target CO isotope component.

[0057] Among them, if CO gas is produced from distillation CO 13 The bottom of the secondary distillation tower in the multi-stage distillation tower of C is obtained, and the bottom of the secondary distillation tower is enriched. 13 C and 17 O and 18 O. As the CO gas flowing out of the bottom of the first distillation tower enters the scrambler, it is supplied to the second distillation tower. 17 O and 18 O mostly with 13 C binding, bottom enrichment 13 C 17 O and 13 C 18 O. In addition, 12 C 16 O and 12 C 17 O is the most volatile of the six components and is more likely to be enriched at the top of the tower. 12 C 16 O and 12 C 17 The content of O at the bottom of the tower is low, so 12 C 16 O and 12 C 17 O screening is the target CO isotope composition, and 12 C 16 The mass number of O is 28, which can be directly calculated based on the signal value of mass number 28 detected by mass spectrometer. 12 C 17 O screening is the target CO isotope composition.

[0058] Furthermore, if CO gas is produced from CO distillation 13 The bottom of the secondary distillation tower in the multi-stage distillation tower of C is obtained due to 12 C 17 The content of O is extremely low and can be ignored. When measured by mass spectrometer, it is difficult to detect it due to the detection limit of the mass spectrometer. 12 C 17 O, which can be determined based on the signal value at mass number 29 13 C 16 The abundance of O. 13 C 16 The abundance of O 13 C 18 The abundance of O and 13 The abundance value of C can be obtained 13 C17 The abundance of O. 13 C 17 The abundance value of O and the detection signal value at mass number 30 can be obtained. 12 C 18 The abundance of O.

[0059] Specifically, 12 C 17 After the abundance of O is determined to be zero, the abundance values ​​of all components can be obtained. Specifically, the following equation group (12) is used to calculate them.

[0060] [ 12 C 16 O]=

[28]

[0061] [ 13 C 18 O]=

[31]

[0062] [ 13 C 16 O]=

[29]

[0063] [ 13 C 17 O]=

[13] -

[29] -

[31]

[0064] [ 12 C 18 O]=

[30] -

[13] +

[29] +

[31]

[0065] [ 13 C]=

[13]

[0066] [ 18 O]=

[30] -

[13] +

[29] + 2×

[31] (12)

[0067] When the target position of the target tower is the bottom of the primary distillation tower, the target CO isotope composition can be 13 C 17 O. Among them, the bottom of the first distillation tower is enriched with 13 C and slightly enriched 17 O and 18 O. And 13 C 17 O as a heavy isotope combination, 13 C 17 The natural abundance of O is very low, at 0.00041%. 13 C 17 O is the target CO isotope component. Considering the detection limit of the mass spectrometer, it is assumed that 13 C 17 The abundance of O before entering the scrambler is negligible, so13 C 17 The abundance of O is zero.

[0068] When the target position of the target tower is the top of the first-stage distillation tower, the target CO isotope composition can be 13 C 17 O or 12 C 17 O. Among them, the light components are enriched at the top of the first-stage distillation tower, and the main components of the enrichment are 12 C 16 O, and 13 C 17 O is depleted at the top of the tower, and its content will be lower than the concentration when the feed is made, that is, at the top of the first-stage distillation tower 13 C 17 The abundance of O is lower than 13 C 17 The natural abundance of O is 0.00041%, so it can be selected 13 C 17 O is the target CO isotope component. Considering the detection limit of the mass spectrometer, 13 C 17 The abundance of O is negligible, so it can be determined that 13 C 17 The abundance of O is zero.

[0069] Furthermore, according to 13 C 17 The abundance of O 13 C 18 The abundance of O and 13 The abundance value of C can be obtained 13 C 16 The abundance of O. 13 C 17 The abundance value of O and the detection signal value at mass number 30 can be obtained. 12 C 18 The abundance value of O. Specifically, 13 C 17 After the abundance of O is determined to be zero, the abundance values ​​of all components can be calculated using the following equation group (13).

[0070] [ 12 C 16 O]=

[28]

[0071] [ 13 C 18 O]=

[31]

[0072] [ 12 C 18 O]=

[30]

[0073] [13 C 16 O]=

[13] -

[31]

[0074] [ 12 C 17 O]=

[29] -

[13] +

[31]

[0075] [ 13 C]=

[13]

[0076] [ 18 O]=

[30] +

[31] (13)

[0077] As described above, the possible composition of CO gas is analyzed according to the working principle of the multi-stage distillation tower, ignoring 12 C 17 O. 13 C 16 O. 12 C 18 O. 13 C 17 O, the abundance of all components can be obtained, thereby determining the abundance of carbon isotopes and oxygen isotopes in CO gas. Figure 3 FIG. 1 is a schematic diagram of a method for determining the abundance value of a target CO isotope component according to another embodiment of the present application. Figure 3 As shown, the method 300 for determining the abundance value of the target CO isotope component may include operations S301 to S304 when it is determined that the signal value corresponding to the mass number of carbon in the CO gas does not meet the threshold.

[0078] In operation S301 , the natural abundance value of a target CO isotope component is obtained.

[0079] In operation S302 , an abundance upper limit value of the target CO isotope component is determined based on the natural abundance value of the target CO isotope component and the state in which the target CO isotope component is not separated.

[0080] In operation S303 , the lower limit of the abundance of the target CO isotope composition is determined according to the natural abundance of the target CO isotope composition, the natural abundance of carbon in the target CO isotope composition, and the state of separation of the target CO isotope composition.

[0081] In operation S304 , the abundance value of the target CO isotope component is determined according to the detection limit of the mass spectrometer, the upper abundance limit value, and the lower abundance limit value.

[0082] In this embodiment, the threshold value can be determined based on the actual signal peak measured by the mass spectrometer. For example, the threshold value can be one ten-thousandth of the signal value at a mass number of 28. When the signal value corresponding to the mass number of the carbon isotope in the CO gas is less than the threshold value, it is determined that the signal value corresponding to the mass number of the carbon isotope in the CO gas does not meet the threshold value.

[0083] Specifically, the natural abundance value of the target CO isotope component can be obtained from a database storing the natural abundance values ​​of CO isotopes. According to the state in which the target CO isotope component is not separated, the natural abundance value of the target CO isotope component can be determined as the upper abundance limit value of the target CO isotope component. According to the state in which the target CO isotope component is separated, the natural abundance value of the target CO isotope component and the natural abundance value of the carbon isotope in the target CO isotope component can be used to determine the lower abundance limit value of the target CO isotope component. According to the model of the mass spectrometer, the detection limit is obtained from a detection information library storing different models of mass spectrometers. The abundance value of the target CO isotope component can be determined based on the average value of the upper abundance limit value and the lower abundance limit value and the detection limit of the mass spectrometer.

[0084] In some embodiments, when detecting CO at the top of a primary distillation column using a mass spectrometer, if the peak at mass 13 is too small to be accurately measured, the above method 200 cannot be used to determine the abundance. In this case, the abundance can only be calculated using the signal values ​​of the CO peaks at masses 28, 29, 30, and 31, and there is no way to distinguish between the two components at mass 29. Therefore, the method in this embodiment can be used to determine the isotopic abundance.

[0085] in, 13 The natural abundance of C is 1.10%, and almost all of it is 13 C 16 O, 17 The natural abundance of O is 0.038%, and almost all of it is 12 C 17 O. When separating in a primary distillation tower, if 13 C 16 O and 12 C 17 O relative to 12 C 16 O have the same separation, then 13 C 16 O and 12 C 17 O will be present in the same proportion at the top of the first distillation column. However, 12 C 17 Compared to O, 13 C 16 O and 12 C 16O separation is stronger, which means 13 C 16 O is better enriched as it goes down the tower and better depleted as it goes up the tower from the feed point. 13 C 16 O, the top of the first distillation tower 12 C 17 O is greater than the natural abundance. In this embodiment, 12 C 17 O screening is the target CO isotope composition.

[0086] Further, the method 300 is used to determine 12 C 17 The abundance of O. Specifically, 12 C 17 If separation does not occur, 12 C 17 The upper limit of the abundance of the O component may be 0.038%. 12 C 17 If 13 C 16 O, their ratio will be constant. In mass spectrometry, 12 C 17 The proportion of O in the peak with mass number 29 is 0.038 / (0.038+1.10)=3.3%. 13 Under normal process conditions of C, in mass spectrometry detection, the peak with mass number 29 is about 0.5% of the peak with mass number 28, and the peak with mass number 30 is even smaller. Therefore, 12 C 17 The lower limit of the abundance of the O component can be 0.038 / (0.038+1.10)*0.5%, that is, 0.017%. Considering the measurement accuracy of the mass spectrometer, 12 C 17 The lower and upper limits of O abundance can be 0.02% and 0.04%, respectively. 12 C 17 The O component is always the same, so we can get 12 C 17 The abundance value of O may be 0.03%.

[0087] because[ 12 C 17 O] = 0.03%. According to formulas (7) to (11), the following equation group (14) can be obtained to determine the abundance value of each component.

[0088] [ 12 C 16 O]=

[28]

[0089] [13 C 18 O]=

[31]

[0090] [ 13 C 16 O]=

[29] -0.03%

[0091] [ 13 C 17 O]=

[13] -

[31] -

[29] +0.03%

[0092] [ 12 C 18 O]=

[30] -

[13] +

[31] +

[29] -0.03%

[0093] [ 13 C]=

[13]

[0094] [ 18 O]=

[30] -

[13] + 2×

[31] +

[29] -0.03% (14)

[0095] As described above, determining the abundance value of the target CO isotope component based on the detection limit, upper abundance limit, and lower abundance limit of the mass spectrometer is beneficial for further combining the detection signal value to accurately determine the abundance value of the oxygen isotope in the CO gas, thereby improving the accuracy of calculating the separation efficiency of the target tower and facilitating accurate monitoring and adjustment of the target tower.

[0096] Figure 4 According to the embodiment of the present application, CO is produced by distillation 13 Flow chart of C. Figure 4 As shown, distillation CO production 13 In the process of C, the CO gas enters the primary distillation tower 1 for separation, and the CO gas flowing out of the bottom of the primary distillation tower 1 passes through the scrambler 2 and enters the secondary distillation tower 3 for separation.

[0097] It should be noted that Figure 4 The arrow in the middle indicates the direction of CO gas inflow and outflow. Both the primary distillation tower 1 and the secondary distillation tower 3 can be composed of multiple distillation towers connected in series.

[0098] In some embodiments, the target position of the target tower may include any one of the following: the bottom 4 of the primary distillation tower, the top 5 of the primary distillation tower, and the bottom 6 of the secondary distillation tower.

[0099] In some embodiments, it is also necessary to measure the CO at the top 7 of the secondary distillation tower. However, the concentration of no CO isotope component in the CO sample at this analysis point can be ignored. 13The abundance of C may be as high as 60%. This is because in the above embodiment, when measuring the CO at the bottom of the secondary distillation tower, it is assumed that there is no 12 C 17 O remains at the bottom of the secondary distillation tower, then there should be 12 C 17 O. If the mass spectrometer can detect a large number of 13 C 18 O (mass 31), indicating that it is also likely to exist 13 C 17 O.

[0100] Therefore, to measure the isotopic abundance of CO at this location, Figure 5 FIG. 1 is a schematic diagram showing a method for measuring isotope abundance in CO gas according to another embodiment of the present application. Figure 5 As shown, the method 500 for measuring isotope abundance in CO gas may further include operations S501 to S503.

[0101] In operation S501, it is determined that the CO gas is produced from the distillation of CO 13 In the case of obtaining CO from the top 7 of the secondary distillation tower in the multi-stage distillation tower of C, the first CO isotope composition and the second CO isotope composition are determined according to the components enriched in the top 7 of the secondary distillation tower.

[0102] In operation S502 , difference information between the abundance value of the first CO isotope component and the abundance value of the second CO isotope component is determined based on the detection signal value.

[0103] In operation S503 , the abundance value of the carbon isotope in the CO gas and the abundance value of the oxygen isotope in the CO gas are determined based on the difference information.

[0104] In this embodiment, the first CO isotope composition can be 12 C 17 O, the second CO isotope composition can be 13 C 17 The difference between the abundance value of the first CO isotope component and the abundance value of the second CO isotope component can be expressed as follows (15):

[0105] [ 12 C 17 O]-[ 13 C 17 O]=

[12] / (

[12] +

[13] )-(

[29] +

[30] ) / (

[28] +

[29] +

[30] +

[31] ) (15)

[0107] The abundance values ​​of carbon isotopes in the CO gas and oxygen isotopes in the CO gas can be determined based on the difference information. Specifically, when the abundance value of the first CO isotope component is less than the abundance value of the second CO isotope component, the abundance value of the first CO isotope component is assumed to be zero, and the abundance values ​​of the carbon isotopes and oxygen isotopes in the CO gas are calculated. When the abundance value of the first CO isotope component is greater than the abundance value of the second CO isotope component, the abundance value of the second CO isotope component is assumed to be zero, and the abundance values ​​of the carbon isotopes and oxygen isotopes in the CO gas are calculated. The method in this embodiment can be used to calculate the abundance value of each component and realize the detection and analysis of CO at the top of the secondary distillation tower.

[0108] In this embodiment, the mass spectrometer detects the CO gas signal and obtains the detection signal value to solve the above-mentioned difference information. If the above-mentioned difference information can indicate that the solution result is greater than zero, it can be assumed that [ 13 C 17 O] is zero, and then according to formulas (6) to (11), the following equation group (16) can be obtained:

[0109] [ 12 C 16 O]=

[28]

[0110] [ 13 C 18 O]=

[31]

[0111] [ 12 C 18 O]=

[30]

[0112] [ 13 C 16 O]=

[13] -

[31]

[0113] [ 12 C 17 O]=

[29] -

[13] +

[31]

[0114] [ 13 C]=

[13]

[0115] [ 18 O]=

[30] +

[31] (16)

[0116] If the above difference information can indicate that the solution result is less than zero, it can be assumed that [ 12 C 17 O] is zero, and then according to formulas (6) to (11), the following equation group (17) can be obtained:

[0117] [ 12 C 16 O]=

[28]

[0118] [ 13 C 18 O]=

[31]

[0119] [ 13 C 16 O]=

[29]

[0120] [ 13 C 17 O]=

[13] -

[29] -

[31]

[0121] [ 12 C 18 O]=

[30] -

[13] +

[29] +

[31]

[0122] [ 13 C]=

[13]

[0123] [ 18 O]=

[30] -

[13] +

[29] + 2×

[31] (17)

[0124] It should be noted that this example is only a specific embodiment of the present application and cannot limit the scope of protection of the present application.

[0125] As described above, by producing 13 After CO gas is collected from the top of the secondary distillation column in process C, a first CO isotope composition and a second CO isotope composition are determined based on the components enriched at the top of the secondary distillation column. Based on the detection signal value, the difference between the abundance of the first CO isotope composition and the abundance of the second CO isotope composition is determined. Based on this difference, the abundance of the carbon isotope in the CO gas and the abundance of the oxygen isotope in the CO gas are determined. This allows the determination of the CO isotope composition at the top of the secondary distillation column, thereby improving the calculation accuracy of the distillation column separation efficiency.

[0126] In the embodiment of the present application, the method for measuring the isotope abundance in CO gas can be applied to the distillation production 13 C process. It should be noted that distillation production 13 Process C is cryogenic distillation production 13 C, wherein the low temperature can be -40℃~-20℃.

[0127] In some embodiments, the operation status of the distillation column process can also be monitored. Specifically, the distillation column separation efficiency can be determined by measuring the isotope abundance of CO gas, and the operation status of the distillation column process can be monitored based on the distillation column separation efficiency.

[0128] In some embodiments, the parameters of the distillation column process can also be adjusted. Specifically, the distillation column separation efficiency can be determined by measuring the isotopic abundance of the CO gas. If the distillation column separation efficiency does not meet the actual separation requirements, the parameters of the distillation column process can be adjusted to improve the distillation column separation efficiency.

[0129] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Any content not described in detail in the present invention may be adapted from existing technologies.

Claims

1. A method for measuring the isotope abundance in CO gas, wherein: include: The CO gas is detected by a mass spectrometer to obtain a detection signal value, wherein the CO gas is produced by distilling CO 13 The target position of the target tower in the multi-stage distillation tower of C is obtained, and the target position of the target tower includes any one of the following: the bottom of the first-stage distillation tower, the top of the first-stage distillation tower, and the bottom of the second-stage distillation tower; the CO gas includes all CO isotope components; According to the working principle of the target tower during the distillation of CO gas, a target CO isotope component is screened from all the CO isotope components; Determining the abundance value of the target CO isotope component according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component; Determining the abundance value of the carbon isotope and the abundance value of the oxygen isotope in the CO gas according to the detection signal value and the abundance value of the target CO isotope component; The signal value corresponding to the mass number of the CO gas and the signal value corresponding to the mass number of the carbon isotope in the CO gas; Determining the abundance value of the target CO isotope component according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component includes: When it is determined that the signal value corresponding to the mass number of the carbon isotope in the CO gas meets the threshold: Obtaining the natural abundance value of the target CO isotope component; Determining a detection limit of the mass spectrometer based on the mass spectrometer; The abundance value of the target CO isotope component is determined according to the detection limit of the mass spectrometer and the natural abundance value of the target CO isotope component.

2. The method according to claim 1, wherein Determining the abundance value of the target CO isotope component based on the mass spectrometer and the natural abundance value of the target CO isotope component includes: When it is determined that the signal value corresponding to the mass number of the carbon isotope in the CO gas does not meet the threshold: Obtaining the natural abundance value of the target CO isotope component; Determining an upper limit of the abundance of the target CO isotope component according to the natural abundance value of the target CO isotope component and the state in which the target CO isotope component is not separated in the target tower; Determining the lower limit of the abundance of the target CO isotope component according to the natural abundance value of the target CO isotope component, the natural abundance value of the carbon isotope in the target CO isotope component, and the state of separation of the target CO isotope component in the target tower; The abundance value of the target CO isotope component is determined according to the detection limit of the mass spectrometer, the upper abundance limit value, and the lower abundance limit value.

3. The method according to claim 1, wherein The method of screening the target CO isotope component from all the CO isotope components according to the target tower comprises: Analyzing the components enriched at the target position of the target tower; According to the analysis results, the target CO isotope component is screened from CO isotope components with a mass number of 29 or 30.

4. The method according to claim 3, wherein: When the target position of the target tower is the bottom of the primary distillation tower, the target CO isotope composition is 13 C 17 O.

5. The method according to claim 3, wherein When the target position of the target tower is the bottom of the secondary distillation tower, the target CO isotope composition is 12 C 17 O.

6. The method according to claim 3, wherein: When the target position of the target tower is the top of the primary distillation tower, the target CO isotope composition is 13 C 17 O or 12 C 17 O.

7. The method according to claim 1, wherein The distillation CO production 13 In the process of C, the CO gas enters a primary distillation tower for separation, and the CO gas flowing out of the bottom of the primary distillation tower passes through a scrambler and then enters a secondary distillation tower for separation; the method further includes: In determining whether the CO gas is produced from distilled CO 13 In the case of obtaining CO from the top of the secondary distillation tower in the multi-stage distillation tower C, determining the first CO isotope composition and the second CO isotope composition according to the components enriched at the top of the secondary distillation tower; Determining difference information between an abundance value of the first CO isotope component and an abundance value of the second CO isotope component according to the detection signal value; The abundance value of the carbon isotope in the CO gas and the abundance value of the oxygen isotope in the CO gas are determined based on the difference information.

8. The method according to claim 7, wherein: Determining the abundance value of the carbon isotope in the CO gas and the abundance value of the oxygen isotope in the CO gas based on the difference includes: When the abundance value of the first CO isotope component is less than the abundance value of the second CO isotope component, assuming that the abundance value of the first CO isotope component is zero, calculating the abundance values ​​of carbon isotopes and oxygen isotopes in the CO gas; When the abundance value of the first CO isotope component is greater than the abundance value of the second CO isotope component, the abundance values ​​of carbon isotopes and oxygen isotopes in the CO gas are calculated assuming that the abundance value of the second CO isotope component is zero.

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