Device and method for detecting content of flexible insoluble substances in oil product

Abstract

The invention relates to the technical field of petrochemical engineering oil product detection, in particular to a device and a method for detecting the content of flexible insoluble substances in an oil product. The device comprises a solvent conveying unit, an extraction unit, a solvent recovery unit and an automatic control unit, an extractor in the extraction unit is sequentially connected with an online refractometer and an electromagnetic valve; the automatic controller receives the concentration of soluble substances in the extracting solution detected by the online refractometer and controls the flow of the injection pump, the switching interval of the electromagnetic valve and the working state of the heating assembly according to the comparison result of the concentration and the preset extraction end point concentration. According to the method, the concentration of soluble substances in an extracting solution is detected in real time, and extraction is automatically stopped when the concentration is lower than the extraction end point concentration. Automatic control of the extraction process is achieved, the extraction end point is judged through the concentration quantitative index instead of manual naked eyes, and the accuracy and repeatability of the detection result are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of petrochemical oil testing technology, specifically to a device and method for detecting the content of flexible insoluble matter in oil products. Background Technology

[0002] Insoluble matter content is a crucial quality indicator for petroleum products, and its accurate measurement is essential for optimizing production processes and controlling product quality. Heavy oils, asphalt, and coal tar are widely used as industrial fuels, raw materials for deep processing, and road paving. Excessive insoluble matter content directly reduces the product's stability, adhesion, and combustion efficiency, leading to problems such as cracking of asphalt pavements, incomplete combustion of fuels, and substandard quality of deep-processed products, ultimately affecting the performance and lifespan of end products. Furthermore, accurate detection of flexible insoluble matter content is also necessary to meet industry quality standards and regulate product quality. It is of great significance for enhancing product market competitiveness and promoting the standardized and refined development of related industries such as petroleum refining and coal chemical engineering.

[0003] Conventional oil insolubles are mostly divided into rigid inorganic impurities, carbonaceous particles and other hard insolubles, as well as flexible insolubles composed of gums, asphaltenes, polymer flocs, aged sludge and other substances. Flexible insolubles are characterized by their soft texture, high viscosity, easy agglomeration, difficulty in filtration and retention, and easy migration with the liquid flow. Their physical properties are significantly different from those of hard insolubles.

[0004] The detection of insoluble matter content in oil products often employs the principle of organic solvent extraction and separation. The industry commonly uses organic solvents such as n-heptane, toluene, and quinoline as extraction solvents. This involves relying on the good solubility of the solvent in oil-soluble components. The sample is wrapped in filter paper, and extraction is performed by heating and reflux within a specified time. This process fully dissolves and separates the soluble components in the oil, leaving the remaining, less soluble components in the filter paper, which are the insoluble matter. The content of the corresponding components is then calculated by drying and weighing. Existing extraction and separation methods are effective for the qualitative and quantitative detection of conventional hard insoluble matter. However, for flexible, flocculent, and highly viscous insoluble matter, existing conventional extraction devices and methods still struggle to achieve accurate detection. The main reasons are as follows: (1) Existing insoluble matter detection devices mostly rely on manual operation. The devices are simple in structure and lack standardized and precise temperature control and quantitative liquid addition components. During the detection process, there are problems such as the extraction solvent temperature being affected by environmental heat dissipation and the solvent reflux rate being difficult to control. These problems not only affect the extraction efficiency but also fail to guarantee the accuracy and repeatability of the results. (2) In the current methods for detecting insoluble matter in oil products, there is a lack of unified and clear quantitative standards for determining the extraction endpoint of flexible insoluble matter. The criteria are rather vague, and the determination of whether the extraction is complete relies heavily on manual observation of color differences, which is easily affected by subjective factors. It is difficult to unify the judgment standards of different testers and different test batches. At best, this will lead to incomplete extraction and the presence of flexible insoluble matter in the oil, resulting in lower test values. At worst, it will lead to over-extraction and the inclusion of excess impurities, further increasing the detection error and resulting in poor consistency of test results.

[0005] Even when tests are conducted in accordance with current standards for testing insoluble matter in oils, due to limitations such as incomplete standard details and ambiguous endpoint criteria, existing testing devices and methods still cannot achieve accurate quantitative detection of flexible insoluble matter after repeated practice, and the accuracy and repeatability of test results are difficult to guarantee.

[0006] While existing technologies have developed mature criteria such as fixed extraction time, observation of solvent color changes, and detection of evaporation residues, the applicant has found that these methods still have the following shortcomings in practical applications: ① For oils with low insoluble content, the fixed extraction time may be insufficient, leading to incomplete washing of soluble components and higher insoluble content test results; ② For oils with high insoluble content, the fixed extraction time may be too long, causing flexible insoluble matter to penetrate the filter paper pores, resulting in lower test results. Therefore, it is necessary to propose a more scientific and fundamental extraction termination criterion. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a device and method for detecting the content of flexible insoluble matter in oil products. This invention can solve the technical problems of low automation and unreasonable extraction termination criteria in current insoluble matter detection devices, which lead to poor detection accuracy and repeatability.

[0008] The technical solution of the present invention is: a device for detecting the content of flexible insoluble matter in oil products, comprising a solvent delivery unit, an extraction unit, a solvent recovery unit, and an automatic control unit; The extraction unit includes an extractor, an online refractometer, and a solenoid valve, with the liquid outlet of the extractor connected in sequence to the online refractometer and the solenoid valve. The solvent recovery unit includes an extraction bottle, a condenser tube, and a solvent recovery tank. The inlet of the extraction bottle is connected to the solenoid valve, and the outlet of the extraction bottle is connected to the solvent recovery tank through the condenser tube. The solvent delivery unit includes an injection pump, the inlet of which is connected to the solvent recovery tank, and its outlet is connected to the inlet of the extractor via a solvent delivery pipeline. The automatic control unit includes an automatic controller, which is electrically connected to the online refractometer, the solenoid valve, the injection pump, and the heating assembly disposed on the extractor and the extraction bottle, respectively. The automatic controller can receive the concentration of soluble substances in the extract as detected in real time by the online refractometer, and control the flow rate of the injection pump, the on / off state of the solenoid valve, and the working state of the heating component based on the comparison result of the concentration with the preset extraction endpoint concentration.

[0009] Furthermore, the extractor is externally encased in an extractor constant temperature heating jacket, which is connected to the automatic controller via an extractor thermocouple; the extraction bottle is externally encased in an extraction bottle heating jacket, which is connected to the automatic controller via an extraction bottle thermocouple.

[0010] Furthermore, the online refractometer is equipped with a micro-filtration and defoaming device at the sample inlet end to remove solid particles and bubbles from the extract.

[0011] A method for detecting the content of flexible insoluble matter in oil products, characterized by comprising the following steps: Step S1: Add solvent to the solvent recovery tank, place the filter paper package containing the test sample into the extractor, and set the constant temperature and extraction endpoint concentration of the extractor through the automatic controller; Step S2: Start the injection pump to deliver the solvent from the solvent recovery tank to the extractor for sample extraction; Step S3: The extract flows sequentially through the online refractometer and the solenoid valve into the extraction bottle. The online refractometer detects the concentration of soluble substances in the extract in real time and feeds it back to the automatic controller. Step S4: After the extract in the extraction bottle is heated, the solvent vaporizes and enters the condenser to condense and flow back to the solvent recovery tank for recycling. Step S5: The automatic controller dynamically adjusts the flow rate of the injection pump, the switching interval of the solenoid valve, and the heating power of the extraction bottle according to the real-time received soluble concentration. Step S6: When the concentration of soluble matter detected by the online refractometer continues to be lower than the preset extraction endpoint concentration, the automatic controller controls each execution component to stop working and end the extraction.

[0012] Furthermore, the extraction endpoint concentration is 0.05%, which is the mass fraction of the soluble substance in the extract.

[0013] Compared with the prior art, the present invention has the following advantages: The device of this invention enables real-time dynamic detection and adjustment of process parameters such as extraction temperature, solvent flow rate, and extract concentration. It can adjust the extraction rate according to the concentration of soluble substances, greatly improving the automation level of the device and increasing extraction efficiency.

[0014] This invention provides a novel method for determining the extraction endpoint, enabling online detection of the concentration of soluble substances in the extract. Extraction ends when the concentration drops to the extraction endpoint concentration, reducing manual intervention, minimizing human error, and improving the accuracy of experimental results.

[0015] Experimental verification shows that the device of the present invention can obtain stable and accurate detection results under different ambient temperatures, effectively overcoming the technical defects of conventional devices that are affected by ambient temperature, resulting in large fluctuations in detection results. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of a conventional extraction device in the prior art; Figure 1 The components are: 1. Extractor thermocouple, 2. Extractor constant temperature heating jacket, 3. Extractor, 4. Online refractometer, 5. Solenoid valve, 6. Extraction bottle, 7. Extraction bottle heating jacket, 8. Extraction bottle thermocouple, 9. Condenser, 10. Solvent recovery tank, 11. Injection pump, 12. Solvent supply line, 13. Automatic controller; Figure 2 In the middle: 14. Condenser, 15. Extraction tube, 16. Connecting tube, 17. Siphon tube, 18. Extraction bottle, 19. Heating mantle. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example 1; like Figure 1 As shown, the present invention provides a device for detecting the content of flexible insoluble matter in oil products. The device includes a solvent delivery unit, an extraction unit, a solvent recovery unit, and an automatic control unit.

[0019] The extraction unit mainly consists of an extractor 3, an online refractometer 4, and a solenoid valve 5 connected in sequence. The extractor 3 is used to hold the filter paper package containing the sample, and its exterior is wrapped with an extractor constant temperature heating jacket 2. This heating jacket is connected to the automatic controller 13 through the extractor thermocouple 1 to achieve precise control of the extraction temperature.

[0020] The solvent recovery unit consists of an extraction bottle 6, a condenser 9, and a solvent recovery tank 10 connected together. The inlet of the extraction bottle 6 is connected to a solenoid valve 5, and its exterior is covered by an extraction bottle heating jacket 7, which is connected to an automatic controller 13 via an extraction bottle thermocouple 8. The outlet of the extraction bottle 6 is connected to the solvent recovery tank 10 via the condenser 9 for the condensation and recovery of solvent vapor.

[0021] The solvent delivery unit consists of an injection pump 11 and a solvent delivery pipeline 12. The inlet of the injection pump 11 is connected to the solvent recovery tank 10, and its outlet is connected to the inlet of the extractor 3 through the solvent delivery pipeline 12.

[0022] The automatic control unit consists of an automatic controller 13, which is electrically connected to the online refractometer 4, the solenoid valve 5, the constant temperature heating jacket 2 of the extractor, the heating jacket 7 of the extraction bottle, the thermocouple 1 of the extractor, the thermocouple 8 of the extraction bottle, and the injection pump 11, forming a closed-loop control circuit and integrating data acquisition and storage functions.

[0023] The online refractometer 4 is equipped with a micro-filter defoaming device at the sample inlet to remove solid particles and bubbles from the extract, ensuring the accuracy of the test results.

[0024] This invention does not directly measure the original solution using an online refractometer for samples with low transmittance. Instead, the sample is diluted with a solvent at a high ratio before testing. Using a refractometer through dilution is a conventional method. After dilution, the sample transmittance is significantly improved, fully meeting the measurement requirements of the online refractometer.

[0025] Example 2; The method for detecting the content of flexible insoluble matter in oil products provided by this invention, using the above-mentioned apparatus, specifically includes the following steps: 1. Add an appropriate amount of solvent to the solvent recovery tank 10, put the filter paper package containing the test sample into the extractor 3, cover the extractor with the top cover, connect the condenser to the circulating water, turn on the automatic controller 13, and set the constant temperature of the extractor and the concentration of the extract at the extraction endpoint. 2. The injection pump 11 starts working, delivering the solvent in the solvent recovery tank 10 to the extractor 3; 3. The constant temperature heating jacket 2 of the extractor starts to work, and the automatic controller 13 adjusts the heating power to control the temperature at the set value; 4. The heating jacket 7 of the extraction bottle starts working, and the automatic controller 13 adjusts the heating power according to the flow rate of the injection pump; 5. The online refractometer 4 starts working, and monitors the concentration of soluble substances in the extractant of extractor 3 in real time, and feeds it back to the automatic controller 13; 6. Solenoid valve 5 starts working, and its opening and closing are controlled by automatic controller 13. Automatic controller 13 calculates the interval time for solenoid valve 5 to open based on the flow rate. 7. After passing through the extractor 3, the extract flows into the extraction bottle 6 through the online refractometer 4 and the solenoid valve 5. The solvent in the extract is heated and vaporized in the extraction bottle 6 and enters the condenser 9. It is condensed into liquid in the condenser 9 and flows back to the solvent recovery tank 10. 8. During the extraction experiment, the automatic controller 13 adjusts the flow rate of the syringe pump 11, the opening time interval of the solenoid valve 5, and the heating power of the extraction bottle according to the detection results of the online refractometer 4, thereby controlling the extraction rate; 9. When the online refractometer 4 continuously detects that the concentration of soluble matter in the extract is less than the set extraction endpoint concentration, the automatic controller 13 controls the injection pump 11, heating device, solenoid valve 5 and online refractometer 4 to stop working, and the extraction ends.

[0026] Example 3; This embodiment uses asphaltene content testing as an example, employing the apparatus and method described in the above embodiment, along with conventional extraction devices (such as...). Figure 2 A comparative test was conducted (as shown in the figure).

[0027] Experimental steps: 1. Add 500ml of n-heptane to the solvent recovery tank, place the filter paper package containing the test sample into the extractor, cover the extractor, connect the condenser to the circulating water, turn on the automatic controller, set the constant temperature of the extractor to 50℃, and the extraction endpoint concentration of the extract to 0.05% (mass fraction). Start the experiment. 2. The device extracts according to preset parameters and procedures, with the heating device, injection pump, solenoid valve, and online refractometer working automatically and in coordination; 3. When the online refractometer continuously detects that the concentration of soluble matter in the extract is less than 0.05%, the automatic controller will stop all components from working, and the extraction will end. 4. Test the asphaltene content using conventional extraction equipment under the same conditions, such as... Figure 2 As shown, a conventional extraction device includes a condenser 14, an extraction tube 15, a connecting tube 16, a siphon tube 17, an extraction bottle 18, and a heating mantle 19.

[0028] Its working principle is as follows: the heating jacket 19 heats the solvent in the extraction bottle 18. After the solvent is heated and vaporized, it rises through the connecting tube 16 into the condenser tube 14. After condensing into liquid in the condenser tube 14, it drips into the extraction tube 15 to soak and extract the sample wrapped in the filter paper.

[0029] When the liquid level of the extract in the extraction tube 15 reaches the top of the siphon tube 17, the siphon effect occurs, and the extract, along with the dissolved soluble matter, flows back into the extraction bottle 18, completing one extraction cycle. This process is repeated until the extraction endpoint is manually determined (usually by the solvent color lightening or the fixed extraction time being reached).

[0030] The results of the comparison with the device of the present invention are shown in Table 1.

[0031] ; As can be seen from Table 1, the test results of the conventional extraction device differed significantly under different ambient temperatures. The test result was 17.22% at 15℃ and 13.54% at 30℃. The temperature change caused a deviation of 3.68 percentage points. This is mainly because the conventional device lacks precise temperature control. At the same time, the ambient temperature has a significant impact on the temperature of the extractant and the extraction efficiency.

[0032] The device of this invention achieved extraction yields of 12.29% and 12.41% at ambient temperatures of 15℃ and 30℃, respectively, with a deviation of only 0.12 percentage points, demonstrating excellent stability and repeatability. This is attributed to the device's real-time dynamic adjustment of parameters such as extraction temperature, solvent flow rate, and extract concentration via an automatic controller, effectively eliminating environmental interference and ensuring the accuracy of extraction endpoint determination.

[0033] Example 4; This embodiment takes the test of toluene insoluble content as an example, and compares the apparatus and method of the above embodiment with a conventional extraction apparatus.

[0034] Experimental steps: 1. Add 500ml of toluene to the solvent recovery tank, place the filter paper package containing the test sample into the extractor, cover the extractor, connect the condenser to the circulating water, turn on the automatic controller, set the constant temperature of the extractor to 95℃, and the extraction endpoint concentration of the extract to 0.05% (mass fraction). 2. The device extracts according to the preset parameters and program, and the heating device, injection pump, solenoid valve and online refractometer begin to work together; 3. When the online refractometer continuously detects that the concentration of soluble matter in the extract is less than 0.05%, the automatic controller will stop all components from working, and the extraction will end. 4. The content of toluene insoluble matter was tested using a conventional extraction device under the same conditions and compared with the device of the present invention. The results are shown in Table 2.

[0035] ; As shown in Table 2, the test results of the conventional extraction device differed significantly under different ambient temperatures. The result was 7.02% at 15℃ and 4.19% at 30℃, with temperature changes causing a deviation of 2.83 percentage points. This further confirms that the conventional device is significantly affected by ambient temperature.

[0036] The device of the present invention achieved test results of 2.73% and 2.57% at ambient temperatures of 15℃ and 30℃, respectively, with a deviation of only 0.16 percentage points, which further proves that the device of the present invention has good environmental adaptability and test repeatability.

[0037] The device and method for detecting the content of flexible insoluble matter in oil provided by the present invention detects the concentration of soluble matter in the extract in real time by using an online refractometer, and uses the concentration dropping to a preset threshold as the basis for judging the extraction endpoint. Combined with the dynamic adjustment of each execution component by an automatic controller, it effectively solves the technical problems of strong subjectivity of manual judgment, large interference from environmental temperature, and poor repeatability of detection results in the prior art.

[0038] In addition, the device and method of the present invention can obtain stable and accurate detection results under different environmental conditions, and have good value for promotion and application.

[0039] This invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this invention, and the changed content still falls within the protection scope of this invention.

Claims

1. A device for detecting the content of flexible insoluble matter in oil products, characterized in that, It includes a solvent delivery unit, an extraction unit, a solvent recovery unit, and an automatic control unit; The extraction unit includes an extractor, an online refractometer, and a solenoid valve, with the liquid outlet of the extractor connected in sequence to the online refractometer and the solenoid valve. The solvent recovery unit includes an extraction bottle, a condenser tube, and a solvent recovery tank. The inlet of the extraction bottle is connected to the solenoid valve, and the outlet of the extraction bottle is connected to the solvent recovery tank through the condenser tube. The solvent delivery unit includes an injection pump, the inlet of which is connected to the solvent recovery tank, and its outlet is connected to the inlet of the extractor via a solvent delivery pipeline. The automatic control unit includes an automatic controller, which is electrically connected to the online refractometer, the solenoid valve, the injection pump, and the heating assembly disposed on the extractor and the extraction bottle, respectively. The automatic controller can receive the concentration of soluble substances in the extract as detected in real time by the online refractometer, and control the flow rate of the injection pump, the on / off state of the solenoid valve, and the working state of the heating component based on the comparison result of the concentration with the preset extraction endpoint concentration.

2. The device for detecting the content of flexible insoluble matter in oil products according to claim 1, characterized in that: The extractor is externally encased in an extractor constant temperature heating jacket, which is connected to the automatic controller via an extractor thermocouple; the extraction bottle is externally encased in an extraction bottle heating jacket, which is connected to the automatic controller via an extraction bottle thermocouple.

3. The device for detecting the content of flexible insoluble matter in oil products according to claim 1, characterized in that: The online refractometer is equipped with a micro-filtration and defoaming device at the sample inlet to remove solid particles and bubbles from the extract.

4. A method for detecting the content of flexible insoluble matter in oil products, characterized in that, The device for detecting the content of flexible insoluble matter in oil products according to any one of claims 1-3 includes the following steps: Step S1: Add solvent to the solvent recovery tank, place the filter paper package containing the test sample into the extractor, and set the constant temperature and extraction endpoint concentration of the extractor through an automatic controller; Step S2: Start the injection pump to deliver the solvent in the solvent recovery tank to the extractor for sample extraction; Step S3: The extract flows sequentially through an online refractometer and a solenoid valve into the extraction bottle, and the online refractometer detects the concentration of soluble matter in the extract in real time and feeds it back to the automatic controller; Step S4: After the extract in the extraction bottle is heated, the solvent vaporizes and enters the condenser to condense and flow back to the solvent recovery tank for recycling; Step S5: The automatic controller dynamically adjusts the flow rate of the injection pump, the opening and closing interval of the solenoid valve, and the heating power of the extraction bottle according to the real-time received concentration of soluble matter; Step S6: When the concentration of soluble matter detected by the online refractometer is continuously lower than the preset extraction endpoint concentration, the automatic controller controls each execution component to stop working and end the extraction.

5. The method for detecting the content of flexible insoluble matter in oil products according to claim 4, characterized in that: The extraction endpoint concentration is 0.05%, which is the mass fraction of soluble matter in the extract.

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