Method for detecting organic matters in acidic vanadium solution

Abstract

The invention relates to the field of detection of organic matters, in particular to a method for detecting organic matters in an acidic vanadium solution, which comprises the following steps: by taking the acidic vanadium solution containing the organic matters as a detection object, carrying out organic phase extraction (oscillation shaking table and jet extraction), standing and organic phase extract liquid separation, and then carrying out water absorption filtration on the organic phase extract liquid to remove moisture in the extract liquid, thereby obtaining the organic matters in the acidic vanadium solution. And measuring the content of an organic phase in the organic phase extract liquor by adopting an infrared spectrophotometric method, and further calculating the content of organic matters in the acidic vanadium solution. According to the method, the content of trace organic matters in the acidic vanadium solution can be accurately measured, the precision reaches 0.1 ppm, and the measurement accuracy and stability are improved. The method is simple to operate and can be used for accurately measuring the trace organic phase in the acidic vanadium solution.

Description

Technical Field

[0001] The invention belongs to the field of organic matter detection, and in particular relates to a method for detecting organic matter in an acidic vanadium solution. Background Art

[0002] Liquid flow battery is a new type of energy storage system with high energy efficiency, long life, flexible design and environmental friendliness. It has important commercial value for the development of large-scale energy storage needs of new power systems.

[0003] Vanadium electrolyte is the core of liquid flow battery energy storage and energy conversion. As a carrier of active substances, electrolyte is one of the most important components of all-vanadium liquid flow batteries. It is the active substance for energy storage and conversion of vanadium battery systems, which directly determines the operating performance of the battery. Its cost accounts for 32% to 50% of the total cost of the energy storage system. The preparation methods of vanadium electrolyte generally include chemical synthesis, electrolysis, etc. Among them, the advantage of chemical synthesis is that the production equipment is simple, but the solid dissolution rate is slow, and the added reducing agent will remain in the vanadium electrolyte and is difficult to eradicate, affecting the purity and performance of the vanadium electrolyte.

[0004] At present, in the process of extracting vanadium by extraction, solvent oil (kerosene and sulfonated kerosene) and extractants (such as P204 and N235, etc.) are inevitably temporarily retained in the acidic vanadium solution. The residue of organic matter will destroy the structure of the battery diaphragm or adsorb on the surface of the diaphragm to block the channel, causing the effective area of ​​the diaphragm to decrease, resulting in a decrease in the operating efficiency of the vanadium battery, reducing the service life of the vanadium battery, and causing irreversible effects on the vanadium battery diaphragm. At the same time, the accumulation of organic matter will also cause it to adsorb on the electrode surface and greatly reduce the electrode activity. For this reason, accurate measurement of the organic content in the vanadium solution is particularly important for the preparation of high-performance vanadium electrolytes. The traditional method of measuring organic matter has poor reproducibility when measuring the organic content in acidic vanadium solutions, and the fluctuation range of the measured values ​​is relatively large, which is particularly unsuitable for the detection of trace organic phases in acidic vanadium solutions.

[0005] Therefore, it is necessary to improve the traditional method of measuring the organic phase, narrow the fluctuation range of the measurement results, and improve the accuracy, so as to improve the operating performance of the vanadium battery and extend its service life. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for detecting organic matter in an acidic vanadium solution. The method can accurately measure the content of trace organic matter in an acidic vanadium solution with an accuracy of 0.1ppm, thereby improving the accuracy and stability of the measurement. The method is simple to operate and can be used for accurate measurement of trace organic phases in an acidic vanadium solution. The technical solution of the present invention is:

[0007] A method for detecting organic matter in an acidic vanadium solution, which takes the acidic vanadium solution containing organic matter as the detection object, extracts the organic phase, stands still, separates the organic phase extract, then absorbs and filters the organic phase extract to remove water in the extract, and then uses infrared spectrophotometry to measure the content of the organic phase in the organic phase extract, thereby calculating the content of the organic matter in the acidic vanadium solution. The organic phase extraction includes two processes: an oscillating shaker and a jet extraction.

[0008] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the acidic vanadium solution containing organic matter includes an acidic vanadium solution containing organic matter produced by vanadium extraction from waste catalyst, stone coal, low-vanadium steel slag, petroleum coke or petroleum ash, wherein the organic matter content is 0.1-100 mg / L.

[0009] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the content of the detected organic matter is the total content of one or a mixture of several of kerosene, sulfonated kerosene, P204, N235, P507, petroleum ether, ethanol, propane, butane, hexane, ether, and ethyl acetate.

[0010] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the device used in the organic phase extraction process includes an oscillating shaker device, a reagent bottle, a jet extractor, an infrared spectrophotometer for oil measurement, and a water absorption and filtration device; the organic phase extractant is tetrachloroethylene, and the tetrachloroethylene is of infrared spectrum pure (IR) grade; the volume ratio of the organic phase extractant to the acidic vanadium solution is 10:500mL to 100:500mL, preferably 30:500mL to 50:500mL.

[0011] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the oscillation frequency of the oscillating shaker is 50 to 250 times per minute, and the oscillation time is 10 to 120 minutes; the capacity of the reagent bottle used in the oscillating shaker process is 1 to 2 times the total volume of the solution to be shaken; and the jet extraction time is 0.5 to 4 hours, preferably 1-3 hours.

[0012] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the water absorption and filtering device is composed of a glass sand core funnel and a desiccant.

[0013] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the glass sand core funnel of the water absorption and filtering device includes one of G1 type (inner diameter 20-30um, filtering out coarse precipitates and colloidal precipitates), G2 type (inner diameter 10-15um, filtering out coarse precipitates and gas washing), G3 type (inner diameter 4.5-9um, filtering out fine precipitates, filtering mercury), G4 type (inner diameter 3-4um, filtering out fine precipitates or very fine precipitates), G5 type (inner diameter 1.5-2.5um, filtering out larger rod-shaped bacteria and yeast), G6 type (inner diameter <1.5um, filtering out 1.5-0.6um bacteria); the desiccant is one or a mixture of anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium sulfate, anhydrous potassium sulfate, and anhydrous strontium sulfate; the height of the desiccant laid flat in the glass sand core funnel is 0.1-2.0cm, preferably 0.5-1.5cm.

[0014] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, the infrared spectrophotometric oil measuring instrument uses tetrachloroethylene filtered by a water absorption filter device as the blank zero point of the measurement.

[0015] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, when the infrared spectrophotometer for oil testing measures the sample to be tested, the cuvette is placed under the glass sand core funnel to directly receive tetrachloroethylene until the liquid level is 2 / 3 of the height of the cuvette, and then placed in the sample chamber to start measuring.

[0016] Furthermore, in the above-mentioned method for detecting organic matter in an acidic vanadium solution, when the infrared spectrophotometer for measuring oil is measuring the sample to be tested, the tetrachloroethylene collection and measurement operation is repeated three times, and each measurement is scanned at least three times.

[0017] The design concept of the present invention is to extract organic matter in the acidic vanadium solution by an organic phase extraction method combined with oscillation + jet extraction, separate the organic phase extract after standing, filter the organic phase extract to remove water in the extract, and then use infrared spectrophotometry to measure the content of organic phase in the organic phase extract, and then calculate the content of organic matter in the acidic vanadium solution.

[0018] 1. The present invention is simple to operate and highly safe.

[0019] 2. The present invention solves the problem of low accuracy in measuring trace organic matter in vanadium solution, improves the stability of measuring the organic matter content in vanadium solution, and has higher stability and reproducibility of measurement results, with an accuracy of 0.1 ppm. DETAILED DESCRIPTION

[0020] In the specific implementation process, the present invention uses an acidic vanadium solution containing trace amounts of kerosene and P204 as a raw material and uses an organic phase extraction method to measure the contents of trace amounts of kerosene and P204 in the acidic vanadium solution.

[0021] Below, the present invention is further described in detail by examples. Example 1

[0022] Take 500mL of kerosene and P204 acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 1.3mg / L, add 50mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 200 times / minute, the oscillation time is 50 minutes, move into the jet extractor, extract 7 times, and let stand for 58 minutes. Spread a layer of anhydrous sodium sulfate on the filter paper of the glass funnel, take tetrachloroethylene to filter, and place the cuvette directly under the funnel outlet. The liquid level is 2 / 3 of the height of the cuvette. Set the volume of the extractant to 50mL and the volume of the water sample to 500mL. The number of scans is 3 times, and the filtration and scanning operations are repeated for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, a blank experiment is performed on tetrachloroethylene, and its measurement value is zero). The measurement result range is 2.1~2.8mg / L. Example 2

[0023] Take 500mL of sulfonated kerosene and P204 acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 1.3mg / L, add 40mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 230 times / min, the oscillation time is 52 minutes, move into the jet extractor, extract 7 times, and let stand for 61 minutes. The height of anhydrous potassium sulfate and anhydrous sodium sulfate laid flat in the G1 type 40mL glass sand core funnel is 1cm, take tetrachloroethylene to filter, the cuvette is directly placed under the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, set the extractant volume to 50mL, the water sample volume to 500mL, the number of scans is 3 times, repeat the filtration and scanning operations for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, a blank experiment is performed on tetrachloroethylene, and its measurement value is zero). The measurement result range is 1.7~2.3mg / L. Example 3

[0024] Take 500mL of acidic vanadium solution containing N235 and P507 in a 1000mL reagent bottle, the organic phase content is 1.3mg / L, add 50mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 210 times / min, the oscillation time is 50 minutes, move into the jet extractor, extract 6 times, and let stand for 50 minutes. The height of anhydrous sodium sulfate laid flat in the G3 type 40mL glass sand core funnel is 1.3cm, take tetrachloroethylene to filter, the cuvette is directly placed under the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, set the extractant volume to 50mL, the water sample volume to 500mL, the number of scans is 3 times, repeat the filtration and scanning operations for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, the tetrachloroethylene is subjected to a blank experiment, and its measurement value is the zero point). The measurement result range is 1.3~1.7mg / L. Example 4

[0025] Take 500mL of propane and P204 acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 1.3mg / L, add 40mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 180 times / minute, the oscillation time is 50 minutes, move into the jet extractor, extract 7 times, and let stand for 60 minutes. The height of anhydrous sodium sulfate laid flat in the G4 type 40mL glass sand core funnel is 1cm, take tetrachloroethylene to filter, the cuvette is directly placed below the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, set the extractant volume to 50mL, the water sample volume to 500mL, the number of scans is 3 times, repeat the filtration and scanning operations for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, the tetrachloroethylene is subjected to a blank experiment, and its measurement value is the zero point). The measurement result range is 1.2~1.4mg / L. Example 5

[0026] Take 500mL of petroleum ether and butane acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 1.3mg / L, add 40mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 250 times / minute, the oscillation time is 60 minutes, move into the jet extractor, extract 10 times, and let stand for 85 minutes. The height of anhydrous magnesium sulfate laid flat in the G5 type 40mL glass sand core funnel is 1.2cm, take tetrachloroethylene to filter, the cuvette is directly placed under the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, the extractant volume is set to 50mL, the water sample volume is 500mL, the number of scans is 3 times, and the filtration and scanning operations are repeated for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, the tetrachloroethylene is subjected to a blank experiment, and its measurement value is the zero point). The measurement result range is 1.2~1.4mg / L. Example 6

[0027] Take 500mL of ethanol and butane acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 26.6mg / L, add 50mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 200 times / min, the oscillation time is 50 minutes, move into the jet extractor, extract 7 times, and let stand for 60 minutes. The height of anhydrous calcium sulfate in the G4 type 40mL glass sand core funnel is 1.1cm, take tetrachloroethylene to filter, the cuvette is directly placed under the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, the extractant volume is set to 50mL, the water sample volume is 500mL, the number of scans is 3 times, and the filtration and scanning operations are repeated for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, the tetrachloroethylene is used as a blank experiment, and its measurement value is zero). The measurement result range is 26.2~26.9mg / L. Example 7

[0028] Take 500mL of sulfonated kerosene and hexane acidic vanadium solution in a 1000mL reagent bottle, the organic phase content is 13.9mg / L, add 50mL of tetrachloroethylene, shake it manually for 30 minutes, transfer it to the jet extractor, extract it 7 times, and let it stand for 70 minutes. The height of anhydrous sodium sulfate spread in the G4 type 40mL glass sand core funnel is 1cm, and tetrachloroethylene is taken for filtration. The cuvette is placed directly below the funnel outlet, and the liquid level is 2 / 3 of the height of the cuvette. Set the volume of the extractant to 50mL and the volume of the water sample to 500mL, and the number of scans is 3 times. Repeat the filtering and scanning operations for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, a blank experiment is performed on tetrachloroethylene, and its measurement value is the zero point). The measurement result range is 10.7~12.2mg / L. Example 8

[0029] Take 500mL of acidic vanadium solution containing ether and ethyl acetate in a 1000mL reagent bottle, the organic phase content is 0.55mg / L, add 30mL of tetrachloroethylene, the oscillation frequency of the oscillating shaker is 200 times / min, the oscillation time is 50 minutes, move into the jet extractor, extract 5 times, and let stand for 55 minutes. The height of anhydrous sodium sulfate and anhydrous strontium sulfate laid flat in the G4 type 40mL glass sand core funnel is 1.2cm, take tetrachloroethylene to filter, the cuvette is directly placed under the funnel outlet, the liquid level is 2 / 3 of the height of the cuvette, the extractant volume is set to 50mL, the water sample volume is 500mL, the number of scans is 3 times, and the filtration and scanning operations are repeated for a total of 3 times. The measurement zero point is the pure tetrachloroethylene extractant as the zero point (before each measurement of the sample to be tested, the tetrachloroethylene is subjected to a blank experiment, and its measurement value is zero). The measurement result range is 0.52~0.56mg / L.

[0030] The results of the embodiments show that the detection result of organic matter in the acidic vanadium solution of the present invention is accurate, the fluctuation range of the detection result is small, and the content of trace organic matter in the acidic vanadium solution can be measured more accurately, thereby providing a basis for optimizing the electrolyte composition and improving the operating efficiency and service life of the vanadium battery.

Claims

1. A method for detecting organic matter in an acidic vanadium solution, characterized in that: The acidic vanadium solution containing organic matter is taken as the detection object, and the organic phase is extracted, allowed to stand, and the organic phase extract is separated. Then, the organic phase extract is filtered to remove the water in the extract, and then the content of the organic phase in the organic phase extract is measured by infrared spectrophotometry, and then the content of organic matter in the acidic vanadium solution is calculated. The organic phase extraction includes two processes: an oscillating shaker and a jet extraction.

2. The method for detecting organic matter in an acidic vanadium solution according to claim 1, characterized in that: The acidic vanadium solution containing organic matter includes the acidic vanadium solution containing organic matter produced by the process of extracting vanadium from waste catalyst, stone coal, low-vanadium steel slag, petroleum coke or petroleum ash, wherein the organic matter content is 0.1-100 mg / L.

3. The method for detecting organic matter in an acidic vanadium solution according to claim 1, characterized in that: The content of the detected organic matter is the total content of one or a mixture of kerosene, sulfonated kerosene, P204, N235, P507, petroleum ether, ethanol, propane, butane, hexane, ether, and ethyl acetate.

4. The method for detecting organic matter in an acidic vanadium solution according to claim 1, characterized in that: The devices used in the organic phase extraction process include an oscillating shaker, a reagent bottle, a jet extractor, an infrared spectrophotometer for measuring oil, and a water absorption filter; the organic phase extractant is tetrachloroethylene, and the tetrachloroethylene is infrared spectrum pure (IR) grade; the volume ratio of the organic phase extractant to the acidic vanadium solution is 10:500mL to 100:500mL.

5. The method for detecting organic matter in an acidic vanadium solution according to claim 1, characterized in that: The oscillation frequency of the oscillating shaker is 50 to 250 times per minute, and the oscillation time is 10 to 120 minutes; the capacity of the reagent bottle used in the oscillating shaker process is 1 to 2 times the total volume of the shaken solution; and the jet extraction time is 0.5 to 4 hours.

6. The method for detecting organic matter in an acidic vanadium solution according to claim 4, characterized in that: The water absorption and filtering device is composed of a glass sand core funnel and a desiccant.

7. The method for detecting organic matter in an acidic vanadium solution according to claim 6, characterized in that: The glass sand core funnel of the water absorption and filtering device includes one of G1 type, G2 type, G3 type, G4 type, G5 type and G6 type; the desiccant is one of anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium sulfate, anhydrous potassium sulfate and anhydrous strontium sulfate or a mixture of several thereof; the height of the desiccant laid flat in the glass sand core funnel is 0.1-2.0 cm.

8. The method for detecting organic matter in an acidic vanadium solution according to claim 4, characterized in that: The infrared spectrophotometer for oil analysis uses tetrachloroethylene filtered through a water absorption filter as the blank zero point for measurement.

9. The method for detecting organic matter in an acidic vanadium solution according to claim 4, characterized in that: When the infrared spectrophotometer is used to measure the sample to be tested, the cuvette is placed under the glass sand core funnel to directly receive tetrachloroethylene until the liquid level is 2 / 3 of the height of the cuvette, and then placed in the sample chamber to start measuring.

10. The method for detecting organic matter in an acidic vanadium solution according to claim 9, characterized in that: When measuring the sample with the infrared spectrophotometer, the tetrachloroethylene collection and measurement operations are repeated three times, with at least three scans for each measurement.