Method for determining proportion of biochar component in liquid fuel

Abstract

The invention provides a method for measuring the proportion of a biochar component in a liquid fuel, which comprises the following steps of: preparing a test solution, namely mixing the liquid fuel and a scintillator according to a specified proportion, and uniformly dissolving the scintillator and the liquid fuel to obtain the test solution; a test step: placing the test liquid in a liquid scintillation counter, and determining within a specified time to obtain a scintillation counting rate test value; and a biochar proportion calculation step: calculating the biochar component proportion of the liquid fuel according to the test value and the total carbon amount of the liquid fuel. The method disclosed by the invention is high in accuracy and strong in timeliness, and can provide guidance for quality monitoring and synthesis mechanism exploration of various liquid fuels.

Description

Technical Field

[0001] The present invention relates to the field of liquid fuel detection, and in particular to a method for determining the proportion of biocarbon components in liquid fuel. Background Art

[0002] Biomass is carbon neutral. How to accurately determine the proportion of biocarbon in bio-based and fossil-based mixed liquid fuels is the key to liquid fuel quality monitoring and synthesis mechanism research.

[0003] at present 14 The C method uses the difference in radiocarbon content between biofuels and fossil fuels to accurately determine the proportion of biocarbon in mixed fuels. 14 Among the common methods for C detection, the gas proportional counting method has low accuracy and cannot meet the accuracy requirements for determining the proportion of biocarbon components in liquid fuels; although the accelerator mass spectrometry-graphitization method has high accuracy, its high cost makes it difficult to apply it on a large scale in the field of liquid fuel detection; although the liquid scintillation counting-benzene synthesis method has the advantages of both low cost and high precision, the sample preparation time is too long and the test timeliness is low.

[0004] From the above technical status, it is necessary to propose a method that can accurately and efficiently determine the proportion of biochar in liquid fuel. The testing principle of liquid scintillation counting is to indirectly determine the content of a substance by measuring the number of flashes per unit time after the scintillator receives radioactive carbon decay energy. 14 According to this test method, the mass fraction of carbon in the substance to be tested is positively correlated with the test accuracy, that is, the higher the mass fraction of carbon in the substance to be tested, the higher the corresponding test accuracy. Therefore, in traditional technology, the carbon source to be tested is generally converted into benzene before testing. 14 However, not all types of carbon sources can be efficiently and selectively converted to benzene. Different compounds have different reactivities and yields during the conversion process. The conversion process may introduce additional complexity and uncertainty, especially when dealing with a large number of samples. These problems may become more prominent. Summary of the invention

[0005] In response to the above problems, the present invention proposes a method for determining the proportion of biocarbon components in liquid fuel. The method is based on the fact that liquid fuel also has a relatively high carbon mass fraction. Through scintillator and quenching correction, the proportion of biocarbon components in liquid fuel can be accurately and efficiently determined.

[0006] The method for determining the proportion of biogenic carbon components in liquid fuel provided by the present invention is mainly used to determine the proportion of biogenic carbon content in the total carbon content in the liquid fuel, and comprises the following steps:

[0007] The test liquid preparation step is to mix the liquid fuel and the scintillator in a specified ratio, and make the scintillator and the liquid fuel uniformly miscible to obtain the test liquid; the testing step is to place the test liquid in a liquid scintillation counter, and measure it within a specified time to obtain a scintillation counting rate test value; the biocarbon proportion calculation step is to calculate the biocarbon component proportion of the liquid fuel based on the test value and the total carbon content of the liquid fuel.

[0008] According to the technical solution, the method can directly reflect the content of biogenic carbon in the liquid fuel by directly measuring the scintillation count rate after the liquid fuel and the scintillator are mixed, without the need to convert the carbon source to be measured into benzene and then measure its content in the traditional method. 14 The complex chemical conversion process of C activity. Simply place the test liquid in a liquid scintillation counter for measurement, and the result can be obtained in a short time, which improves the test efficiency value E. By accurately measuring the scintillation count rate and combining it with the total carbon content of the liquid fuel, the proportion of biocarbon components can be calculated more accurately, providing reliable data support for the detection and evaluation of biofuels. It should be noted that the scintillator and liquid fuel are uniformly miscible, and the liquid fuel 14 The decay energy released during C decay can be fully and evenly absorbed by the scintillator molecules, thus accurately reflecting the 14 C content.

[0009] Preferably, the method for determining the proportion of biocarbon components in liquid fuel provided by the present invention further includes, after the testing step: a quenching correction step, performing quenching correction on the test liquid, measuring and obtaining a test efficiency value E, and correcting the test value based on the test efficiency value E to obtain a corrected test value; a biocarbon proportion calculation step, calculating the biocarbon proportion of the liquid fuel based on the corrected test value and the total carbon content of the liquid fuel.

[0010] According to the technical solution, in order to accurately obtain the fluorescence counting rate and calculate the 14 C activity, it is necessary to correct the quenching effect through a specific method to accurately calculate the test efficiency value E. The quenching correction step obtains the test efficiency value E through measurement, and corrects the original test value accordingly, thereby eliminating the influence of the quenching effect on the test results. This step significantly improves the accuracy of the test, making the measured scintillation count rate closer to the true value.

[0011] Optionally, the quenching correction step of the method for determining the proportion of biochar components in liquid fuel provided by the present invention adopts an internal standard method, using the built-in radioactive source of a liquid scintillation counter to irradiate the test liquid, obtaining the Compton scattered spectrum distribution, and then analyzing the Compton scattered spectrum distribution through a multi-channel analyzer to obtain a total count, and taking the spectral channel accounting for 75% of the total count as a quenching indication parameter, and finding the test efficiency value E corresponding to the quenching indication parameter.

[0012] According to the technical solution, by directly measuring the influence of the quenching effect on the scintillation count rate and making corrections accordingly, the accuracy of the test results can be significantly improved. This method does not rely on a specific internal standard, but uses the characteristics of the scintillation counter itself for correction, so it is applicable to various types of liquid fuels and scintillators.

[0013] Optionally, the quenching correction step of the method for determining the proportion of biochar in liquid fuel provided by the present invention adopts an external standard method, and a trace amount of 14 The C activity of the standard sample is known and is miscible with the liquid fuel. Then the second test is carried out according to the same test parameters as the first test to obtain the increase value of the counting rate. 14 The test efficiency value E is calculated by corresponding to the theoretical counting rate of C activity.

[0014] According to the technical solution, by adding a standard sample of known activity and measuring the growth value of the count rate, the test efficiency value E can be accurately calculated, thereby accurately correcting the original test value. The external standard method is suitable for the analysis of a large number of samples, especially when the sample components are relatively simple or there are many known components. The external standard method can provide fast and accurate analysis results.

[0015] Furthermore, the biocarbon proportion calculation step of the method for determining the proportion of biocarbon components in liquid fuel provided by the present invention includes two sub-steps:

[0016] 14 C activity calculation, based on the corrected test value and the total carbon content of the liquid fuel, calculate the liquid fuel 14 C activity;

[0017] The proportion of biomass carbon is calculated based on the proportion of liquid fuels. 14 C activity, and calculate the proportion of biocarbon in liquid fuel.

[0018] According to the technical solution, by measuring the scintillator receiving 14 The number of flashes per unit time after C decay can be used to indirectly derive the liquid fuel 14 C activity (i.e. the number of decays that occur per unit time), and then, based on the known total carbon content of the liquid fuel, the proportion of biocarbon is calculated through a certain mathematical model or formula.

[0019] Optionally, the scintillator used in the method for determining the proportion of biochar components in liquid fuel provided by the present invention is: 2-(4-tert-butylbenzene)-5-(4-biphenyl)-1,3,4-oxadiazole, ULTIMA GOLD F or OPTI-FLUOR O.

[0020] According to the technical solution, the above three types of scintillators can be uniformly miscible with the liquid fuel, which can ensure that the liquid fuel 14 The decay energy released during C decay is fully and evenly absorbed by the scintillator molecules, thus accurately reflecting the 14 C content.

[0021] Optionally, the specified time for the test step of the method for determining the proportion of biochar components in liquid fuel provided by the present invention is 1 to 2 hours.

[0022] According to the technical solution, the liquid scintillation counting test reflects the luminescence of the substance to be tested by the number of times the scintillator molecules emit light per unit time. 14 C content, therefore, a shorter measurement may result in a larger error in the test result. The test time should be maintained until the counting rate per unit time is basically stable. According to experimental data, when the measurement is carried out within the time range of 1 to 2 hours, the counting rate per unit time is basically stable.

[0023] Furthermore, the liquid fuel measured by the method for determining the proportion of biocarbon components in liquid fuel provided by the present invention is: a co-refined product of bio-oil and petroleum, a mixed fuel of bio-jet fuel and fossil jet fuel, a mixed fuel of bio-ethanol and gasoline, or a mixed fuel of biodiesel and petroleum diesel.

[0024] The determination method provided by the present invention is suitable for determining the proportion of biocarbon components in various bio-based and fossil-based mixed liquid fuels, and has wide applicability and practicality.

[0025] The present invention also provides a method for determining the proportion of air-derived carbon components in liquid fuel derived from carbon capture technology, that is, applying the above method for determining the proportion of biocarbon components in liquid fuel to determine the proportion of air-derived carbon components in liquid fuel derived from carbon capture technology.

[0026] Furthermore, the present invention provides a method for determining the proportion of air-derived carbon components in carbon capture technology-derived liquid fuels, wherein the carbon capture technology-derived liquid fuels used are: methanol produced by hydrogenation of air carbon dioxide or liquid fuel produced by capturing carbon dioxide from flue gas of coal-fired power plants.

[0027] Through reasonable selection of scintillators and accurate quenching correction schemes, the present invention can use liquid scintillation counting direct test method to accurately and efficiently determine the proportion of biochar components in liquid fuels, thereby providing guidance for liquid fuel quality monitoring and synthesis mechanism research. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of the method for determining the proportion of biocarbon components in liquid fuel in the present invention;

[0029] Figure 2It is a fitting curve diagram of the test efficiency value E and the carbon-based blending ratio obtained by the internal standard method and the external standard method calibration in the embodiment of the present invention;

[0030] Figure 3 is a fitting curve diagram of the count value and the carbon-based blending ratio obtained by the internal standard method correction in an embodiment of the present invention;

[0031] Figure 4 It is a fitting curve diagram of the counting value and the carbon-based blending ratio obtained by external standard method correction in an embodiment of the present invention.

[0032] Explanation of symbols

[0033] m——Mass of liquid fuel taken [g]

[0034] C——Carbon mass fraction of liquid fuel [%]

[0035] D1——Liquid scintillation count rate of the test solution before adding trace standard sample [dpm]

[0036] D2——Liquid scintillation count rate of the test solution after adding a trace amount of standard [dpm]

[0037] D by ——Standard sample added 14 Liquid scintillation count rate corresponding to C activity [dpm]

[0038] D actual ——actual liquid scintillation count rate of the measured liquid fuel [dpm]

[0039] E——Liquid scintillation test efficiency value of the tested fuel [%]

[0040] 14 C——The liquid fuel being tested 14 C activity [pMC]

[0041] 14 C biomass ——The measured liquid fuel biomass sources 14 C activity [pmC]

[0042] R biogenic ——Proportion of biogenic carbon content in the liquid fuel measured [%] DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The method for determining the proportion of biogenic carbon components in liquid fuel provided in this embodiment is mainly used to determine the proportion of biogenic carbon content in the total carbon content in the liquid fuel, and includes the following steps: a test liquid preparation step, mixing, oscillating, and standing the liquid fuel and a scintillator that can be uniformly miscible with the liquid fuel in a specified ratio, so that the scintillator and the liquid fuel are completely and uniformly miscible to obtain a test liquid; a testing step, placing the prepared test liquid in a liquid scintillation counter, measuring within a specified time, and obtaining a scintillation counting rate test value; a quenching correction step, using a specific method to correct the quenching effect to obtain an accurate test efficiency value E; a biogenic carbon proportion calculation step, calculating the liquid fuel according to the test value 14 C activity, and further calculate the proportion of biogenic carbon contained in it to the total carbon.

[0045] Liquid scintillation counting is a method used to measure radioactive isotopes, especially 14 The basic principle of this test method is based on the scintillator receiving radioactive carbon ( 14 C) The energy released by decay is measured by the scintillation light produced. 14 C is an unstable isotope that spontaneously emits electrons (i.e., beta particles) through β decay. These electrons interact with scintillator molecules, causing them to be excited and quickly de-excited, releasing photons (i.e., scintillation light). 14 The more C decay energy (i.e. 14 The higher the C activity, the more scintillation times there are. Therefore, by measuring the number of scintillation times per unit time, the activity of the substance can be indirectly measured. 14 In liquid scintillation counting, the mass fraction of carbon in the substance to be tested is positively correlated with the test accuracy. This is because the higher the carbon mass fraction, the more carbon is contained in the substance per unit mass. 14 The greater the number of C atoms, the higher the probability of the scintillator receiving decay energy, making the number of scintillation more stable and easier to measure, thereby improving the accuracy of the test.

[0046] In this embodiment, bio-oil obtained by hydrogenation and pressurized catalytic pyrolysis of poplar wood is mixed with fossil-based kerosene in different volume ratios, the masses of the two liquid fuels are recorded, and the proportion of bio-carbon in the mixed liquid fuel is calculated according to their respective carbon contents. After the fuels are mixed, the liquid fuel is directly detected by liquid scintillation counting using the method in the embodiment of the present invention, the quenching effect is corrected according to the internal standard method or the external standard method, and then the proportion of bio-carbon is calculated, which is compared with the actual proportion of bio-carbon to verify the accuracy and reliability of the method in the embodiment of the present invention.

[0047] The test solution preparation steps of this embodiment are specifically performed as follows: 10 ml of liquid fuel and 10 ml of ULTIMA GOLDF scintillator are placed in a 20 ml polyethylene ultra-low background scintillation vial with a Teflon coating, and the mass m of the liquid fuel is recorded. The scintillation vial is slightly shaken and allowed to stand until the liquid fuel and the scintillator are completely and evenly miscible.

[0048] 2-(4-tert-Butylbenzene)-5-(4-biphenyl)-1,3,4-oxadiazole (also known as Butyl-PBD), ULTIMAGOLD F scintillant and OPTI-FLUOR O series scintillants are all suitable for liquid scintillation counting of various radioactivity measurements requiring high sensitivity and accuracy. They have excellent scintillation performance and stability, which can ensure the accuracy and reliability of counting.

[0049] In the test steps of this embodiment, it is stipulated that the test time should be stopped until the counting rate per unit time is basically stable, and a test time of 1 to 2 hours is generally used. At the same time, the test parameters should also select a parameter range with both a high test efficiency value E and a low test background. For example, for the ALOKA LSC-LB7 liquid scintillation counter, the test energy channel width range should be selected as 4 to 156 keV, and the test mode should be selected as dpm (counting rate per unit time) mode. Since measurements in a shorter period of time may result in larger errors in the test results, the test time should be maintained until the counting rate per unit time is basically stable. The test time for a single sample can be selected as 1 to 2 hours.

[0050] The quenching correction step of this embodiment includes two correction methods, which can be internal standard correction or external standard correction. The quenching effect refers to the phenomenon that certain substances in the test liquid absorb or scatter photons generated by radioactive decay, resulting in a decrease in the scintillation count rate. These quenching substances may come from the sample itself, scintillators, or impurities in the environment. Due to molecular absorption, the influence of chemical substances and the color of the liquid fuel itself, not all fluorescence can be captured and detected by the photomultiplier tube of the liquid scintillation counter. Especially for darker liquid fuels, the quenching effect is more obvious. In order to accurately obtain the fluorescence count rate and thus calculate the test liquid 14 C activity, it is necessary to correct the quenching effect through a specific method and accurately calculate the test efficiency value E.

[0051] The specific steps of the internal standard method correction in this embodiment are as follows: Because the liquid scintillation counter is equipped with a radioactive source inside, it is used to excite the radioactive isotopes in the test liquid and generate photons. The test liquid is irradiated with the built-in radioactive source of the liquid scintillation counter. When the photons emitted by the radioactive source interact with the electrons in the test liquid, Compton scattering occurs, that is, the photons are scattered by the electrons and lose part of their energy. The energy distribution of these scattered photons (Compton scattering spectrum distribution) is related to the quenching substance content in the test liquid. The obtained Compton scattering spectrum distribution is analyzed by a multi-channel analyzer to obtain the total count. The spectrum channel accounting for 75% of the total count is used as the quenching indication parameter, which reflects the strength of the quenching effect in the test liquid. According to the quenching indication parameter, the corresponding test efficiency value E can be consulted. The test efficiency value E refers to the ratio of the number of photons that the scintillation counter can detect to the theoretical number of photons under actual test conditions due to the existence of the quenching effect. For the ALOKA LSC-LB7 liquid scintillation counter, the built-in 133Ba-740kBq radioactive source is used to irradiate the test liquid to generate a Compton scatter spectrum (count rate-spectrum channel diagram), and the spectrum channel value at which the peak area on the left side accounts for 75% of the total peak area is recorded as the quenching indicator parameter. The test efficiency value E corresponding to the quenching indicator parameter is found according to the test efficiency value E-quenching index parameter diagram prepared using the standard sample when the instrument leaves the factory, that is, the test efficiency value E of the liquid fuel. The original test value is corrected using the found test efficiency value E to obtain the corrected test value. This corrected test value is closer to the true value because it has taken into account the influence of the quenching effect.

[0052] The specific steps of using the external standard method for calibration in this embodiment are as follows: After testing the test liquid once, add a trace amount of a known 14 The standard sample with high C activity and uniform miscibility with liquid fuel should be added in a small amount and accurately controlled to avoid introducing additional quenching effects. The test should be repeated with the same test parameters to ensure the comparability of the test results. Record the scintillation count rate of the second test and calculate the growth value of the count rate. 14 The test efficiency value E is calculated based on the C activity and its theoretical counting rate (which can be calculated through parameters such as the activity of the standard sample and the sensitivity of the counter), as well as the actual measured counting rate growth value. The test efficiency value E reflects the ratio of the actual number of photons that the scintillation counter can detect to the theoretical number of photons in the presence of the quenching effect. The total volume of the test liquid composed of liquid fuel and scintillator is 20ml. The counting rate D1 per unit time can be recorded after one test (the background counting rate has been deducted). Then add 0.01~0.1ml of radioactive carbon standard material to the test liquid, for example, 0.01ml of 0.1mCi / ml GLYCEROL can be added, 14C(U)-glycerol standard substance. After adding a trace amount of standard sample, shake it slightly to make it evenly dissolve. After testing again with the same test parameters, record the count rate D2 (the background count rate has been deducted). Calculate the test efficiency value E based on the difference in count rate before and after and the theoretical count rate increase (i.e., the count rate of the added standard sample).

[0053] When the external standard method is used for calibration, the test efficiency value E is calculated according to formula (1):

[0054]

[0055] After correction by internal standard method or external standard method, the actual counting rate D is calculated according to the counting rate D1 of the test liquid and the test efficiency value E. actual， The calculation formula is formula (2):

[0056]

[0057] The biochar percentage calculation step of this embodiment includes the following sub-steps:

[0058] I. 14 C activity calculation, based on the actual count rate of the test liquid D actual and the total carbon content of the liquid fuel m×C to calculate the liquid fuel 14 C activity, as shown in formula (3):

[0059]

[0060] Among them, 13.56dpm / gC is 14 C Theoretical counting rate of the standard substance.

[0061] II. Calculation of biomass carbon ratio based on liquid fuel 14 C activity is calculated by the ratio of the biogenic carbon contained in the total carbon content, as shown in formula (4):

[0062]

[0063] Among them, pure biomass 14 C activity can be measured from biomass sources of liquid fuels or from the average atmospheric concentration of the year of the test. 14 C activity value.

[0064] The masses and biocarbon percentages of the mixed liquid fuels of this embodiment are shown in Table 1.

[0065] Table 1 Parameters of mixed liquid fuel

[0066] Group Kerosene mass [g] Bio-oil mass [g] Biochar content [%] 1 7.9364 0.0901 1.207 2 7.892 0.1778 2.367 3 7.8414 0.2689 3.559 4 7.6961 0.4553 5.986 5 7.2703 0.9225 12.015 6 6.4435 1.8174 23.286

[0067] Mix the above fuels with 10 ml of ULTIMA GOLD F scintillator in a 20 ml polyethylene ultra-low background scintillation vial with Teflon coating, shake and let stand to make them completely and evenly dissolved. Count values ​​of the samples were measured on an ALOKA LSC-LB7 liquid scintillation counter, and the test time for each sample was 2 hours. Figure 2 The test efficiency values ​​E obtained by the internal standard method and the external standard method for liquid scintillation testing of samples with different proportions of biochar components. It can be seen from the figure that the test efficiency values ​​E obtained by the two methods have the same change trend, but when the quenching effect has a greater influence, there is a slight difference. Figure 3 and Figure 4 The following are the fitting diagrams of the corrected count values ​​obtained by the internal standard method and the external standard method and the actual biochar carbon-based blending ratio. It can be seen from the figure that the slope of the fitting curve is close to 1 and R2 is close to 1, indicating that the method has high accuracy. Tables 2 and 3 are the test efficiency values ​​E, the true value and measured value of the biochar component ratio obtained by the internal standard method and the external standard method, and their relative errors.

[0068] Table 2 Results of internal standard calibration

[0069]

[0070] Table 3 Results of external standard calibration

[0071]

[0072] As can be seen from the table, both quenching correction methods can accurately determine the proportion of biochar in the mixed fuel. When the color of the liquid fuel is darker, the test efficiency value E will decrease, which also illustrates the importance of quenching correction. When the proportion of biochar is higher than 2%, the relative errors of the proportion of biochar determined by the internal standard method and the external standard method are basically within ±10%. For the external standard method, the relative error can be as low as ±5%. When the proportion of biochar is around 1% and 2%, although the relative error is high, the absolute error is more than ±0.6%, which is more accurate.

[0073] In general, the method for determining the proportion of biochar components in liquid fuel proposed in the embodiment of the present invention is effective and feasible. The selected scintillator is uniformly miscible with the liquid fuel, and can achieve accurate and rapid determination of the proportion of biochar components in the liquid fuel, which can provide guidance for quality monitoring of various liquid fuels and exploration of synthesis mechanisms.

[0074] The method provided in this embodiment can be applied to the determination of the proportion of biocarbon components in various liquid fuels, including but not limited to various bio-based and fossil-based mixed liquid fuels such as co-refining products of bio-oil and petroleum, mixed fuels of bio-jet fuel and fossil jet fuel, mixed fuels of bio-ethanol and gasoline, and mixed fuels of biodiesel and petroleum diesel.

[0075] The method provided in this embodiment can also be applied to the determination of the proportion of air-derived carbon components in various carbon capture technology-derived liquid fuels, including but not limited to liquid fuels such as methanol produced by hydrogenation of captured air carbon dioxide and liquid fuels produced by capturing carbon dioxide from flue gas of coal-fired power plants. 14 C activity is equal. By using the carbon dioxide from air and fossil sources 14 C activity difference, this method can be used to distinguish whether the liquid fuel is green liquid fuel. 14 C activity and atmospheric average 14 When the C activity is equal, it can be determined that the source is green liquid fuel made by capturing carbon dioxide from the air; 14 When the C activity is zero, it can be determined that its source is liquid fuel made from capturing carbon dioxide from fossil sources such as carbon dioxide in flue gas from coal-fired power plants; when this type of liquid fuel is mixed with other types of liquid fuels, this method can also be used to determine the proportion of its air-derived carbon component.

[0076] The method for determining the proportion of biogenic carbon in liquid fuels can be applied to determine the proportion of air-derived carbon in liquid fuels derived from carbon capture technology. This is mainly based on the following reasons: biomass contains a certain proportion of 14 C, while fossil fuels do not contain 14 C, so it can be measured by 14 The proportion of biogenic carbon can be estimated by the content of C. Liquid fuels derived from carbon capture technology are usually obtained by capturing carbon dioxide (CO2) from industrial or energy production processes or in the air, and then converting it through a series of chemical reactions or physical processes. The sources of these CO2 are complex and may include air sources (air source CO2 and biogenic CO2). 14 C content) and fossil sources. Similar to the determination of biochar composition, it can be determined by measuring the 14 C (or other suitable isotope markers) to estimate the proportion of carbon components from air.

[0077] Green liquid fuel refers to liquid fuel produced from renewable resources, such as green methanol, which is produced by biomass resources to produce methanol, and green hydrogen and renewable CO2 (i.e., CO2 captured from the air or biomass energy). In addition to green liquid fuel, liquid fuel can also be produced by capturing carbon dioxide from flue gas of coal-fired power plants, but it does not belong to green liquid fuel. This method can be used to distinguish whether a liquid fuel is a green liquid fuel. When it is mixed with other liquid fuels, the proportion of its air-derived or biogenic carbon components can also be determined according to this method.

[0078] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining the proportion of biochar in liquid fuel, characterized in that: The steps include: a test liquid preparation step, mixing the liquid fuel and the scintillator in a specified ratio, and making the scintillator and the liquid fuel uniformly miscible, to obtain a test liquid; The test step is to place the test liquid in a liquid scintillation counter and measure it within a specified time to obtain a scintillation count rate test value; The biocarbon proportion calculation step is to calculate the biocarbon proportion of the liquid fuel according to the test value and the total carbon content of the liquid fuel.

2. The method for determining the proportion of biochar in liquid fuel according to claim 1, characterized in that: The test step also includes: a quenching correction step, performing quenching correction on the test solution, measuring and obtaining a test efficiency value E, and correcting the test value according to the test efficiency value E to obtain a corrected test value; In the biocarbon proportion calculation step, the biocarbon component proportion of the liquid fuel is calculated based on the corrected test value and the total carbon content of the liquid fuel.

3. The method for determining the proportion of biochar in liquid fuel according to claim 2, characterized in that: The quenching correction step adopts the internal standard method, The test liquid is irradiated with the built-in radioactive source of a liquid scintillation counter to obtain the Compton scattered spectrum distribution, and the Compton scattered spectrum distribution is then analyzed by a multi-channel analyzer to obtain the total count, and the spectrum channel accounting for 75% of the total count is used as a quenching indication parameter, and the test efficiency value E corresponding to the quenching indication parameter is obtained.

4. The method for determining the proportion of biochar in liquid fuel according to claim 2, characterized in that: The quenching correction step adopts an external standard method, After the test liquid is tested once, a trace amount of 14 A standard sample with a known C activity and uniformly miscible with the liquid fuel is tested again with the same test parameters as the first test to obtain an increase in the counting rate. The increase is compared with the standard sample. 14 The test efficiency value E is calculated by corresponding to the theoretical counting rate of C activity.

5. The method for determining the proportion of biochar in liquid fuel according to claim 1, characterized in that: The biocarbon percentage calculation step includes two sub-steps: 14 C activity calculation, based on the corrected test value and the total carbon content of the liquid fuel, calculate the liquid fuel 14 C activity; The biomass carbon share is calculated based on the liquid fuel 14 C activity, and calculate the proportion of biocarbon components in the liquid fuel.

6. The method for determining the proportion of biochar in liquid fuel according to claim 1, characterized in that: The scintillator is: 2-(4-tert-butylbenzene)-5-(4-biphenyl)-1,3,4-oxadiazole, ULTIMA GOLD F or OPTI-FLUOR O.

7. The method for determining the proportion of biochar in liquid fuel according to claim 1, characterized in that: The prescribed time is 1 to 2 hours.

8. The method for determining the proportion of biochar in liquid fuel according to claim 1, characterized in that: The liquid fuel is: a co-refined product of bio-oil and petroleum, a mixed fuel of bio-jet fuel and fossil jet fuel, a mixed fuel of bio-ethanol and gasoline, or a mixed fuel of bio-diesel and petroleum diesel.

9. A method for determining the proportion of air-derived carbon components in liquid fuel derived from carbon capture technology, characterized in that: A method for determining the proportion of biochar components in liquid fuel as described in any one of claims 1 to 8.

10. The method for determining the proportion of air-derived carbon components in carbon capture technology-derived liquid fuel according to claim 9, characterized in that: The liquid fuel derived from the carbon capture technology is: methanol produced by hydrogenating carbon dioxide from air or liquid fuel produced by capturing carbon dioxide from flue gas of coal-fired power plants.

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