A method for identifying petroleum products

Abstract

The present disclosure relates to a method for identifying petroleum products. The method calibrates the chromatograms of a known petroleum product and a petroleum product to be tested respectively to obtain retention indices, uses the calibrated retention indices to determine the standard chromatographic peaks and corresponding peak areas in the chromatogram of the known petroleum product corresponding to the measured chromatographic peaks of the petroleum product to be tested, determines the similarity between the measured spectrum and the standard spectrum, and determines the type of the petroleum product to be tested based on the similarity. The method can improve the accuracy of identifying petroleum products.

Description

Technical Field

[0001] The present disclosure relates to the technical field of petrochemical engineering, and in particular, to a method for identifying petroleum products. Background Art

[0002] The chemical composition of petroleum products is relatively complex, and the chemical composition of different types of petroleum products varies greatly. In order to facilitate the management and circulation of petroleum products, it is usually necessary to identify the types of petroleum products.

[0003] In the related art, a chromatographic analysis is performed on the petroleum product to obtain the retention time and peak area or peak height of each chemical component in the petroleum product, and then the retention time and peak area or peak height of each chemical component are compared with the standard chromatograms of various types of petroleum products to determine the type of the petroleum product to be tested.

[0004] However, in the process of realizing the concept of the present disclosure, the inventors found that there are at least the following technical problems in the prior art: the existing chromatographic technology is difficult to achieve chromatographic separation of hydrocarbon compounds with a carbon atom number greater than 12, the chromatographic peaks of hydrocarbon compounds with a carbon atom number greater than 12 in petroleum products may overlap with other chromatographic peaks, and it is difficult to distinguish the various chemical components in petroleum products by retention time, resulting in low accuracy of existing petroleum product identification methods. Summary of the invention

[0005] In order to overcome the problem of low accuracy of existing petroleum product identification methods, the present disclosure provides a method for identifying petroleum products.

[0006] In order to achieve the above object, the present disclosure provides a method for identifying petroleum products, the method comprising:

[0007] Obtain a determination spectrum of the petroleum product to be tested, wherein the determination spectrum includes at least one determination chromatographic peak E xi , each of the measured chromatographic peaks E xi With the corresponding measured retention time t R(xi) and determine the peak area x i ;

[0008] For each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ;

[0009] For a standard spectrum of at least one known petroleum product, the standard spectrum includes at least one standard chromatographic peak, each of which has a corresponding standard retention time and standard peak area:

[0010] -- Correct the standard retention time of each standard chromatographic peak to obtain the standard retention index corresponding to each standard chromatographic peak, and determine the retention index according to the retention index I xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak E yi ;

[0011] --According to each of the determinations of chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determine the similarity S between the measured spectrum and the standard spectrum;

[0012] According to the similarity S, the type of the petroleum product to be tested is determined.

[0013] Optionally, for each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ,include:

[0014] Select a calibration retention time set, and calibrate the chromatographic peak E according to the calibration retention time set. xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi wherein the correction retention time set contains a first correction retention time t R(N) and the second corrected retention time t R(N+m) , and t R(N) ≤t R(xi) <t R(N+m) ; said t R(N) To calibrate the retention time of the chromatographic peak corresponding to the standard sample of normal alkane with carbon number N in the spectrum, the t R(N+m) is the retention time of the chromatographic peak corresponding to the normal alkane standard sample with a carbon atom number of N+m in the calibration spectrum; N is an integer, and 5≤N≤43, when N≤10, m=1, when N>10, 2≤m≤4.

[0015] Optionally, it also includes: obtaining the calibration spectrum from a standard sample mixture; wherein the standard sample mixture includes normal alkanes with carbon atoms of N and N+m, and the test conditions for obtaining the calibration spectrum are the same as the test conditions for obtaining the measurement spectrum.

[0016] Optionally, the determination of the chromatographic peak E according to the correction retention time set xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ,include:

[0017] According to the first corrected retention time t R(N) and the second corrected retention time t R(N+m) According to formula (1), for each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , where formula (1) is:

[0018]

[0019] In formula (1), t0 represents the dead time of measurement.

[0020] Optionally, the retention index I is determined according to xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak E yi ,include:

[0021] The retention index I was determined according to xi and the standard retention index, determining the measured retention index I xi The difference from the standard retention index;

[0022] When the absolute value of the difference does not exceed the preset threshold, it is determined that the standard chromatographic peak indicated by the standard retention index is the same as the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi .

[0023] Optionally, the determination of each chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determining the similarity S between the measured spectrum and the standard spectrum, comprising:

[0024] According to each of the chromatographic peaks E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area yi , the similarity S is calculated using formula (2), where formula (2) is:

[0025]

[0026] In formula (2), n represents the corresponding standard chromatographic peak E in the standard spectrum. yi The number of

[0027] Optionally, the method further comprises:

[0028] Obtain a standard spectrum of at least one known petroleum product, establish a standard spectrum library, and determine the similarity S for each standard spectrum in the standard spectrum library; wherein the test conditions for obtaining the standard spectrum are the same as the test conditions for obtaining the measured spectrum.

[0029] Optionally, determining the type of the petroleum product to be tested according to the similarity S includes:

[0030] The numerical values ​​of the similarity S between the measured spectrum and each of the standard spectrum are determined in turn:

[0031] When S=1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum of the current similarity;

[0032] When S0≤S<1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum with the largest similarity value;

[0033] When S<S0, the petroleum product to be tested does not belong to any of the known petroleum products;

[0034] Here, S0 is any value between 0.90 and 0.95.

[0035] Optionally, the chromatographic method for measuring and obtaining the assay spectrum and the standard spectrum is selected from one of high performance liquid chromatography, high performance capillary electrophoresis chromatography and gas chromatography.

[0036] Optionally, the boiling point of the known petroleum product is 30°C to 550°C; the boiling point of the petroleum product to be tested is 30°C to 550°C.

[0037] Through the above technical scheme, in the method for identifying petroleum products provided by the present disclosure, the chromatograms of the known petroleum product and the petroleum product to be tested are calibrated to obtain retention indices respectively, and the retention indices obtained by calibration are used to determine the standard chromatographic peaks and corresponding peak areas in the chromatogram of the known petroleum product corresponding to the measured chromatographic peaks of the petroleum product to be tested, determine the similarity between the measured spectrum and the standard spectrum, and determine the type of the petroleum product to be tested based on the similarity. This method can improve the accuracy of petroleum product identification.

[0038] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0040] Figure 1 Schematic diagrams of standard spectra of three known petroleum products in the embodiments of the present disclosure are schematically shown. DETAILED DESCRIPTION

[0041] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0042] The present disclosure provides a method for identifying a petroleum product, the method comprising: obtaining a determination spectrum of the petroleum product to be detected, the determination spectrum comprising at least one determination chromatographic peak E xi , each of the measured chromatographic peaks E xi With the corresponding measured retention time t R(xi) and determine the peak area x i ; For each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ; For at least one known petroleum product standard spectrum, the standard spectrum includes at least one standard chromatographic peak, each of the standard chromatographic peaks having a corresponding standard retention time and standard peak area:

[0043] -- Correct the standard retention time of each standard chromatographic peak to obtain the standard retention index corresponding to each standard chromatographic peak, and determine the retention index according to the retention index I xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak E yi ;

[0044] --According to each of the determinations of chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determine the similarity S between the measured spectrum and the standard spectrum;

[0045] According to the similarity S, the type of the petroleum product to be tested is determined.

[0046] In the prior art, when identifying petroleum products, it is necessary to perform chromatographic analysis on the petroleum products to be tested, obtain the retention time of the chromatographic peaks corresponding to each chemical component in the petroleum products, and then compare the retention time of the chromatographic peaks corresponding to each chemical component with the retention time of each chromatographic peak in the standard spectrum of known petroleum products, so as to determine the type of the petroleum products to be tested. However, hydrocarbon compounds with a large number of carbon atoms in petroleum products are difficult to separate in a chromatographic system. Therefore, it is difficult to distinguish hydrocarbon compounds with a large number of carbon atoms in petroleum products by the retention time of each chromatographic peak, resulting in low accuracy of the existing petroleum product identification method.

[0047] In the petroleum product identification method provided in the present invention, the peak area of ​​the measured chromatographic peak and the corresponding standard chromatographic peak with the same retention index is used to determine the similarity between the measured spectrum and the standard spectrum, and the type of the petroleum product to be tested is determined based on the similarity. There is no need to accurately distinguish each chemical component in the petroleum product based on the retention time. Even when the chromatographic peaks corresponding to multiple chemical components overlap, the similarity between the measured spectrum and the standard spectrum can be accurately determined. Therefore, the method of the present invention can significantly improve the accuracy of petroleum product identification.

[0048] The petroleum product identification method disclosed in the present invention has a wide range of applications and can be used to identify petroleum products with a large boiling point range. For example, the boiling point of the known petroleum product can be 30°C to 550°C; the boiling point of the petroleum product to be tested can be 30°C to 550°C.

[0049] Optionally, for each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , which may at least include: selecting a correction retention time set, and determining the chromatographic peak E according to the correction retention time set. xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi wherein the correction retention time set contains a first correction retention time t R(N) and the second corrected retention time t R(N+m) , and t R(N) ≤t R(xi) <t R(N+m) ; said t R(N) To calibrate the retention time of the chromatographic peak corresponding to the standard sample of normal alkane with carbon number N in the spectrum, the t R(N+m)is the retention time of the chromatographic peak corresponding to the normal alkane standard sample with a carbon atom number of N+m in the calibration spectrum; N is an integer, and 5≤N≤43, when N≤10, m=1, when N>10, 2≤m≤4.

[0050] Optionally, it also includes: obtaining the calibration spectrum from a standard sample mixture; wherein the standard sample mixture may at least include normal alkanes with carbon atoms of N and N+m, and the test conditions for obtaining the calibration spectrum are the same as the test conditions for obtaining the measurement spectrum.

[0051] Preferably, the standard sample mixture may include at least normal alkanes with carbon atoms of 5 to 44. The calibration retention time set may include at least the retention time of the chromatographic peak corresponding to the normal alkanes with carbon atoms of 5 to 44 in the calibration spectrum.

[0052] Further, the chromatographic peak E is determined according to the correction retention time set. xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , may include: according to the first correction retention time t R(N) and the second corrected retention time t R(N+m) According to formula (1), for each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , where formula (1) is:

[0053]

[0054] In formula (1), t0 represents the dead time of the measurement. Dead time is a common term in gas chromatography, which refers to the time from sample injection to the peak value of the inert gas peak, reflecting the time it takes for the carrier gas to flow through the system.

[0055] In the present disclosure, the standard retention time of each standard chromatographic peak is corrected to obtain the method and principle of the standard retention index corresponding to each standard chromatographic peak, which is consistent with the method and principle of determining each measured chromatographic peak E as described above. xi The corresponding retention index I xi The method and principle are the same, refer to the above record, and will not be repeated here.

[0056] Optionally, the retention index I is determined according to xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak Eyi , may include: determining the retention index I according to the xi and the standard retention index, determining the measured retention index I xi When the absolute value of the difference does not exceed the preset threshold, the standard chromatographic peak indicated by the standard retention index is determined to be the same as the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi .

[0057] Optionally, when there are multiple standard retention indices with the measured retention index I xi When the absolute value of the difference is less than a preset threshold, the standard chromatographic peak indicated by the standard retention index corresponding to the difference with the smallest absolute value is determined as the peak corresponding to the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi .

[0058] The preset threshold is used to characterize the experimental error allowed to occur during multiple repeated chromatographic analyses, which may be caused by factors such as instruments, experimental environment, and personal operation. The historical data generated by multiple chromatographic analyses can be statistically analyzed to determine the experimental error allowed to occur during multiple chromatographic analyses, and the specific value of the preset threshold is determined based on the experimental error. Exemplarily, the preset threshold can be 0.5 to 10.0, preferably 0.5 to 5, and more preferably 2.

[0059] In the actual identification process, the type of the petroleum product to be tested is not necessarily the same as the type of the known petroleum product selected. xi The standard chromatographic peaks in the standard spectrum do not necessarily correspond one to one. Therefore, the corresponding standard chromatographic peak E in the standard spectrum yi The number of measured chromatographic peaks is less than or equal to the number of standard chromatographic peaks. xi There is no corresponding standard chromatographic peak E in the standard spectrum. yi In this case, this part of the chromatographic peak E will not be measured in the subsequent calculation process. xi The peak area was taken into consideration.

[0060] Optionally, the determination of each chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i, determining the similarity S between the measured spectrum and the standard spectrum may at least include: according to each of the measured chromatographic peaks E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , the similarity S is calculated using formula (2), where formula (2) is:

[0061]

[0062] In formula (2), n represents the corresponding standard chromatographic peak E in the standard spectrum. yi The number of

[0063] The inventors of the present disclosure discovered in the process of realizing the concept of the present disclosure that different types of petroleum products are similar in component composition, so the difference in retention time of the chromatographic peaks corresponding to each component in the chromatogram is small, and it is difficult to accurately distinguish different types of petroleum products by the retention time of the chromatographic peaks. The inventors of the present disclosure further discovered that the content of each component in different types of petroleum products is quite different, which is specifically manifested in that the peak area or peak height of the chromatographic peaks corresponding to each component in the chromatogram is quite different. Therefore, using the peak area of ​​each chromatographic peak to calculate the similarity of different chromatograms, and then determining whether the petroleum products corresponding to the two chromatograms are the same type of petroleum products based on the similarity, can significantly improve the accuracy of petroleum product identification.

[0064] Optionally, the method further includes: obtaining a standard spectrum of at least one known petroleum product, establishing a standard spectrum library, and determining the similarity S for each standard spectrum in the standard spectrum library; wherein the test conditions for obtaining the standard spectrum are the same as the test conditions for obtaining the measured spectrum.

[0065] Optionally, the determination of the type of the petroleum product to be tested based on the similarity S includes: sequentially determining the numerical values ​​of the similarity S between the measured spectrum and each of the standard spectrums: when S=1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum of the current similarity; when S0≤S<1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum with the largest similarity value; when S<S0, the petroleum product to be tested does not belong to any of the known petroleum products; wherein S0 is any value between 0.90 and 0.95. In other words, S0 is a discrimination threshold for determining whether the similarity S is valid, and only a similarity S that is not less than the discrimination threshold can be used to effectively identify the type of the petroleum product to be tested. wherein, the value of S0 can be determined according to actual needs, and in the present disclosure, in order to further improve the accuracy of petroleum product identification, the value of S0 can be, for example, 0.95.

[0066] Optionally, the chromatographic method for measuring and obtaining the assay spectrum and the standard spectrum is selected from one of high performance liquid chromatography, high performance capillary electrophoresis chromatography and gas chromatography. Preferably, the chromatographic method is gas chromatography.

[0067] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0068] The raw materials, reagents, instruments and equipment involved in the embodiments of the present disclosure can be purchased unless otherwise specified. The experimental methods involved in the embodiments of the present disclosure are conventional methods in the field unless otherwise specified.

[0069] In the embodiments of the present disclosure, all samples used for chromatographic analysis are sample stock solutions, or test solutions obtained by diluting the sample stock solutions by the same multiple.

[0070] In the embodiments disclosed herein, the chromatographic methods used in the chromatographic analysis are all gas chromatography, and the chromatographic conditions include: the gas chromatographic column can be an HP-5 chromatographic column, the chromatographic column is 30m long, the inner diameter is 0.32mm, and the coating thickness is 0.5μm. The temperature of the chromatograph inlet can be 250-280°C, the inlet pressure can be 75-95kPa under the voltage stabilization mode, the split ratio can be 10:1-60:1, the injection volume can be 0.5-1μL, the constant flow mode injection, the flow rate can be 0.3-2mL / min, and the carrier gas can be nitrogen. The operating conditions of the chromatographic column are: the initial temperature is 30-40°C, the heating rate is 1-3 / min, the final temperature is 150-200°C, and it is maintained for 5-20min.

[0071] Example 1

[0072] This embodiment is used to illustrate the petroleum product identification method disclosed in the present invention.

[0073] Step 101: Use straight-run gasoline 1 (boiling point range: 35-195° C.) as the petroleum product to be tested, perform chromatographic analysis using the above chromatographic conditions, obtain a measurement spectrum of the petroleum product to be tested, and determine the chromatographic peak E in the measurement spectrum. xi , and each measured chromatographic peak E xi The corresponding retention time t R(xi) and determine the peak area x i , as shown in Table 2.

[0074] Step 102: Select a calibration retention time set, and perform a calibration on each chromatographic peak E according to the calibration retention time set. xi The corresponding retention time t R(xi) Correction, each chromatographic peak E xi The corresponding retention index I xi .

[0075] The calibration retention time set can be determined in advance by: taking a standard sample mixture and performing chromatographic analysis under the above-mentioned chromatographic conditions to obtain a calibration spectrum, and the retention time of the chromatographic peak corresponding to each standard sample in the standard sample mixture in the calibration spectrum constitutes the calibration retention time set. The standard sample mixture includes normal alkanes with carbon atoms of 5 to 44, and therefore, the calibration retention time set includes the retention time of the chromatographic peak corresponding to the normal alkanes with carbon atoms of 5 to 44 in the calibration spectrum. The calibration retention time set determined in this embodiment is shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] According to formula (1), each chromatographic peak E is measured. xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , formula (1) is:

[0080]

[0081] In formula (1), N and N+m represent the number of carbon atoms in the standard sample, N is an integer, 5≤N≤43, and when N≤10, m=1, when N>10, 2≤m≤4; t R(xi) Indicates the retention time of the measurement; t R(N) represents the first calibration retention time; t R(N+m) represents the second corrected retention time, and t R(N) ≤t R(xi) <t R(N+m) ; t0 represents the dead time of the measurement.

[0082] Each chromatographic peak E obtained by correction in this example xi The corresponding retention index I xi As shown in Table 2.

[0083] Table 2

[0084] <![CDATA[Determine chromatographic peak E xi Number]]> <![CDATA[Determine the retention time t R(xi) > <![CDATA[Measure the peak area x i > <![CDATA[Retention index I xi > 1 3.58 386.05 605.099 2 4.11 219.00 632.75 3 4.61 62.72 655.743 4 4.83 213.09 665.08 5 5.02 121.66 672.808 6 5.23 143.02 681.016 7 5.38 68.58 686.679 8 5.45 70.75 689.268 9 5.51 110.93 691.461 10 5.82 372.05 703.623 11 6.33 434.80 728.774 12 7.15 184.84 765.246

[0085] Step 103, obtaining standard spectra of 15 known petroleum products, each standard spectra including standard chromatographic peaks, each standard chromatographic peak having a corresponding standard retention time and a standard peak area; for each standard spectra, calibrating the standard retention time of each standard chromatographic peak to obtain a standard retention index corresponding to each standard chromatographic peak.

[0086] The standard spectrum of the known petroleum product can be determined in advance by taking the known petroleum product and performing chromatographic analysis using the above-mentioned chromatographic conditions to obtain the standard spectrum of the known petroleum product. Figure 1 The standard spectra of three known petroleum products in this example are schematically shown.

[0087] The method for correcting the standard retention time of each standard chromatographic peak to obtain the standard retention index corresponding to each standard chromatographic peak is the same as the method described in step 102. Taking straight-run gasoline as an example, the standard retention index corresponding to each standard chromatographic peak obtained by correction in this embodiment is shown in Table 3.

[0088] Table 3

[0089] Standard chromatographic peak number Standard retention time Standard peak area Standard Retention Index 1 3.60 391.1 606.215 2 4.12 220.0 633.237 3 4.62 64.7 656.177 4 4.84 211.1 665.495 5 5.03 118.7 673.206 6 5.24 143.0 681.398 7 5.39 64.6 687.051 8 5.46 73.8 689.635 9 5.52 109.9 691.824 10 5.82 369.0 703.623 11 6.34 432.8 729.247 12 7.16 184.8 765.665

[0090] Step 104: Determine the retention index I xi and standard retention index to determine the retention index I xi When the absolute value of the difference does not exceed the preset threshold, the standard chromatographic peak indicated by the standard retention index is determined to be the same as the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi , wherein the preset threshold value in this embodiment is 2.0. When there are multiple standard retention indices and the measured retention index I xi When the absolute value of the difference is less than 2.0, the standard chromatographic peak indicated by the standard retention index corresponding to the difference with the smallest absolute value is determined as the peak with the same retention index as the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi .

[0091] Taking straight-run gasoline as an example, the chromatographic peak E determined in this embodiment is xi The corresponding standard chromatographic peak E yi The corresponding relationship is shown in Table 4.

[0092] Table 4

[0093]

[0094] Step 105: for each standard spectrum, according to each determination chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determine the similarity S between the measured spectrum and the standard spectrum.

[0095] Specifically, the similarity S is calculated using formula (2), where formula (2) is:

[0096]

[0097] In formula (2), n represents the corresponding standard chromatographic peak E in the standard spectrum. yi The number of

[0098] Step 106: Determine the type of the petroleum product to be tested according to the similarity S.

[0099] Specifically, the numerical value of the similarity S between the measured spectrum and each standard spectrum is judged in turn: when S=1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum of the current similarity, and the judgment of the remaining known petroleum products can be stopped at this time; when S0≤S<1, that is, the similarities obtained by all standard spectra are less than 1 and greater than S0, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum with the largest similarity value; when S<S0, the petroleum product to be tested does not belong to any known petroleum product, wherein the value of S0 in this embodiment is 0.95. In this embodiment, the similarity values ​​of the measured spectrum and 15 characteristic spectra are shown in Table 5.

[0100] Table 5

[0101] Feature Spectrum Similarity S Straight-run gasoline No. 1 1.000 Straight run gasoline No. 2 0.926 Reforming crude oil No. 1 0.767 Reforming crude oil No. 2 0.704 Reforming crude oil No. 3 0.371 Catalytic gasoline No. 1 0.381 Catalytic gasoline No. 2 0.383 Catalytic gasoline No. 3 0.738 Reforming oil No. 1 0.035 Reforming oil No. 2 0.013 Victory Diesel 0.176 Liaohe Diesel 0.175 Tahe Diesel 0.141 Daqing Diesel 0.024 Crude oil 0.025

[0102] As can be seen from Table 5, after identification, the similarity between the petroleum product to be tested in this embodiment and straight-run gasoline 1 is 1, that is, the method of this embodiment identifies the petroleum product to be tested as straight-run gasoline 1, thereby indicating that the method for identifying petroleum products disclosed in the present invention is accurate and reliable.

[0103] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0104] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0105] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for identifying petroleum products, characterized in that: The method includes: Obtain a determination spectrum of the petroleum product to be tested, wherein the determination spectrum includes at least one determination chromatographic peak E xi , each of the measured chromatographic peaks E xi With the corresponding measured retention time t R(xi) and determine the peak area x i ; For each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ; For a standard spectrum of at least one known petroleum product, the standard spectrum includes at least one standard chromatographic peak, each of which has a corresponding standard retention time and standard peak area: -- Correct the standard retention time of each standard chromatographic peak to obtain the standard retention index corresponding to each standard chromatographic peak, and determine the retention index according to the retention index I xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak E yi ; --According to each of the determinations of chromatographic peak E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determine the similarity S between the measured spectrum and the standard spectrum; Determining the type of the petroleum product to be tested according to the similarity S; Wherein, the retention index I is determined according to the xi and the standard retention index is determined with the measured chromatographic peak E xi The corresponding standard chromatographic peak E yi ,include: The retention index I was determined according to xi and the standard retention index, determining the measured retention index I xi The difference from the standard retention index; When the absolute value of the difference does not exceed the preset threshold, it is determined that the standard chromatographic peak indicated by the standard retention index is the same as the measured retention index I xi The indicated chromatographic peak E xi The corresponding standard chromatographic peak E yi ; According to each of the determination chromatographic peaks E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , determining the similarity S between the measured spectrum and the standard spectrum, comprising: According to each of the chromatographic peaks E xi The peak area x i and each corresponding standard chromatographic peak E yi The standard peak area y i , the similarity S is calculated using formula (2), where formula (2) is: Formula (2), In formula (2), n represents the corresponding standard chromatographic peak E in the standard spectrum. yi the number of The boiling point of the known petroleum product is 30°C to 550°C; the boiling point of the petroleum product to be tested is 30°C to 550°C.

2. The method according to claim 1, characterized in that For each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ,include: Select a calibration retention time set, and calibrate the chromatographic peak E according to the calibration retention time set. xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi wherein the correction retention time set contains a first correction retention time t R(N) and the second corrected retention time t R(N＋m) , and t R(N) ≤t R(xi)＜ t R(N＋m) ; said t R(N) To calibrate the retention time of the chromatographic peak corresponding to the standard sample of normal alkane with carbon number N in the spectrum, the t R(N＋m) is the retention time of the chromatographic peak corresponding to the normal alkane standard sample with a carbon atom number of N+m in the calibration spectrum; N is an integer, and 5≤N≤43, when N≤10, m=1, when N>10, 2≤m≤4.

3. The method according to claim 2, characterized in that The method further comprises: obtaining the calibration spectrum from a standard sample mixture; wherein the standard sample mixture comprises normal alkanes with carbon atoms of N and N+m, and the test conditions for obtaining the calibration spectrum are the same as the test conditions for obtaining the measurement spectrum.

4. The method according to claim 2, characterized in that: The determination of the chromatographic peak E according to the correction retention time set xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi ,include: According to the first corrected retention time t R(N) and the second corrected retention time t R(N＋m) According to formula (1), for each of the chromatographic peaks E xi Determination of retention time t R(xi) Correction is performed to obtain each of the measured chromatographic peaks E xi The corresponding retention index I xi , where formula (1) is: Formula (1) In formula (1), Indicates the dead time of the measurement.

5. The method according to claim 1, characterized in that The method further includes: Obtain a standard spectrum of at least one known petroleum product, establish a standard spectrum library, and determine the similarity S for each standard spectrum in the standard spectrum library; wherein the test conditions for obtaining the standard spectrum are the same as the test conditions for obtaining the measured spectrum.

6. The method according to claim 1 or 5, characterized in that: Determining the type of the petroleum product to be tested according to the similarity S includes: The numerical values ​​of the similarity S between the measured spectrum and each of the standard spectrum are determined in turn: When S=1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum of the current similarity; When S0≤S<1, the petroleum product to be tested is a known petroleum product corresponding to the standard spectrum with the largest similarity value; When S<S0, the petroleum product to be tested does not belong to any of the known petroleum products; Among them, S0 is an arbitrary value between 0.90 and 0.

95.

7. The method according to claim 6, characterized in that The chromatographic method for measuring and obtaining the determination spectrum and the standard spectrum is selected from one of high performance liquid chromatography, high performance capillary electrophoresis chromatography and gas chromatography.

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