Rapid determination method for solid content of oil slurry

Abstract

The invention discloses an oil slurry solid content rapid determination method, which comprises: (1) weighing a container, and recording the weight as G0; (2) oil slurry is heated and stirred, and sampling representativeness is guaranteed; (3) weighing the oil slurry in the step (2), putting the oil slurry into the container treated in the step (1), and recording the weight as G1; (4) heating the oil slurry in the container to evaporate oil gas in the oil slurry until cold oil gas is in the beaker, and continuously heating until residual substances at the bottom of the container are completely ashed; (5) burning black oil gas at the upper part of the container heated in the step (4) in a muffle furnace, cooling the container, cooling in a dryer, weighing, and recording the weight as G2; and (6) calculating the solid content X in the oil slurry by adopting a formula, wherein rho is the density of the oil slurry. The data of the solid content of the oil slurry measured by the measuring method is accurate, and the measuring time is short.

Description

Technical Field

[0001] The present invention relates to the technical field of a method for analyzing and measuring solid content in catalytic oil slurry, and in particular to a method for quickly determining the solid content in oil slurry. Background Art

[0002] Catalytic cracking slurry oil is the heavy fraction extracted from the bottom of the catalytic cracking fractionator, containing a certain amount of catalyst fines. Because the catalyst fines contained in the catalytic cracking slurry oil can easily cause system wear, blockage, and coking during the catalytic cracking unit's circulation process, it is difficult to directly utilize the slurry oil. The catalyst fines must be removed before further use. Accurately and rapidly measuring the solids content in the slurry oil is fundamental to evaluating the efficiency of slurry oil removal and is a technical prerequisite for monitoring the smooth operation of the catalytic cracking unit in refineries.

[0003] Existing methods for measuring the solids content of catalytic oil slurries primarily include: solvent dilution centrifugation (volumetric), ash content, filtration, carbonization and incineration, hot filtration, and extraction. Among these methods, centrifugation can lead to biased results due to the adsorption of asphalt and colloids from the slurry onto the catalyst powder. Furthermore, as the catalytic feedstock becomes heavier, the asphalt and colloid content in the slurry increases. The greater the adsorption of asphalt and colloids onto the catalyst powder, the greater the bias in the results. Therefore, this method cannot meet the requirements for high-content catalytic oil slurry solids analysis. Ash content and carbonization and incineration methods, however, can lead to biased results due to the gases generated during the slurry combustion step, which carry small amounts of solid particles out of the slurry system. Furthermore, direct sintering of the slurry at high temperatures burns away carbon deposits, resulting in low solids content. Furthermore, the carbonized residue from direct combustion of the slurry is dense, making it difficult to burn off during reheating in a muffle furnace, resulting in a prolonged incineration time. When using the extraction method and filtration method for determination, some small-sized particles will escape through the filter membrane due to factors such as the catalyst particle size and the pore size of the filter membrane, resulting in low measurement results; and the test takes a long time. Summary of the Invention

[0004] To solve the above problems, the present invention provides a method for rapid analysis of solid content in oil slurry. By changing the oil slurry burning method, the entrainment of solid matter in the oil slurry during the burning process is reduced, the burning difficulty of solid matter in the oil slurry is reduced, and the analysis time is shortened.

[0005] The technical solution adopted by the present invention is: a method for rapidly determining the solid content of oil slurry, characterized by comprising the following steps:

[0006] (1) Preparation steps: Burn the empty container at high temperature in a muffle furnace, remove the container and cool it for 3 minutes, transfer it to a desiccator without desiccant and cool it to room temperature, weigh it, and record the weight as G0;

[0007] (2) Sample preparation steps: Heat and stir the oil slurry to ensure the representativeness of the sample;

[0008] (3) Sampling step: put the oil slurry in step (2) into the container treated in step (1), and record the weight as G1;

[0009] (4) Ashing step: The oil slurry in the container is placed on an electric furnace and continuously heated until the residual material at the bottom of the container is completely ashed;

[0010] (5) Burning step: Continue to heat the container after the ashing in step (4) to burn the black oil gas on the upper part of the container at high temperature. Take out the container and cool it for 3 minutes. Then transfer it to a desiccant-free dryer and cool it to room temperature. Weigh it to the nearest 0.1 mg. The weight is recorded as G2.

[0011] (6) Calculate the solid content X (g / L) in the oil slurry using the following formula:

[0012] Where ρ is the density of the slurry (g / L).

[0013] The applicant has found through research that when the oil slurry is continuously heated, when the oil slurry temperature in step (4) reaches 350°C, the oil gas begins to evaporate. As the temperature rises, the oil gas continues to evaporate. When the temperature reaches 500°C, the evaporated oil gas decreases significantly. At this time, the bottom of the container is a black substance, and some condensed oil gas remains on the container wall. When the heating is continued, when the temperature of the bottom of the container in step (4) reaches 600-700°C, the residual material at the bottom of the container gradually ashes until it is completely ashed. When the ash is completed, the evaporated oil gas condenses on the upper part of the beaker and appears black, while the lower part is transparent, and the bottom is a gray residual material after ash. The black material remaining at the bottom of the container during ashing is looser than the residual material produced by the ash separation method in the prior art, and burns faster at high temperatures. The evaporated oil gas is lighter and will not carry solid matter in the sample. The oil gas during the ashing process is lighter, and the oil gas adhering to the beaker can be easily burned off in the muffle furnace in the subsequent steps, thereby speeding up the measurement process and improving the accuracy of the measurement results.

[0014] Preferably, the empty container step in step (1) is specifically as follows: heating the container at 775±25°C for 20 minutes, then cooling the container for 3 minutes, transferring it to a desiccant-free dryer and cooling it to room temperature, and weighing it to an accuracy of 0.1 mg.

[0015] Preferably, in step (2), the oil slurry is heated to 60° C. and stirred for at least 5 minutes.

[0016] The inventors have found through research that heating the oil slurry raw material to a constant temperature of 60°C and stirring it for at least 5 minutes can significantly improve the distribution of the solid phase in the oil slurry and ensure the uniformity of sampling.

[0017] Preferably, an electric furnace is used for heating in step (4).

[0018] Compared with other heating equipment, electric furnaces can ensure that the sample reaches a certain high temperature and quickly incinerate the sample.

[0019] Preferably, the ashing time in step (4) is 0.5-1h.

[0020] The applicant has found through experiments that the residual material can be completely ashed when the ashing time reaches 0.5-1h.

[0021] Preferably, in step (5), a muffle furnace is used for heating at a temperature of 775±25° C. for 20 min; the cooling time before drying is 3 min. After cooling for 3 min, the mixture is transferred to a desiccant-free dryer and cooled to room temperature, and weighed to an accuracy of 0.1 mg.

[0022] The purpose of using a muffle furnace for heating and combustion is to burn off the oil and gas condensed on the upper part of the container during the burning process in step (4). There is no need to burn off the charcoal at the bottom. The oil and gas can be easily burned off at high temperatures, saving the combustion time during the measurement process.

[0023] Preferably, the container used is a high temperature resistant quartz beaker.

[0024] Quartz beakers are chosen here because they are more resistant to high temperatures than ordinary beakers and can also be used in electric furnaces and muffle furnaces.

[0025] Beneficial effects of the present invention:

[0026] This application changes the burning method of the oil slurry. When the temperature is between 350-500°C, oil and gas are evaporated. Because the oil and gas are relatively light, the loss of solid matter in the oil slurry due to entrainment will not occur, thus improving the accuracy of the experiment. At the temperature of 500-700°C, the residual material at the bottom of the container is completely ash-reduced. Since the residual material after the oil and gas evaporates is relatively loose, it is looser than the residual material produced by the ash separation method of oil slurry combustion and is easily burned off. This speeds up the subsequent burning process and accelerates the experimental measurement process. The oil and gas during the ash-reduction process are relatively light, and the oil and gas adhering to the beaker can be easily burned off in the muffle furnace at 775±25°C in the subsequent step, speeding up the experimental measurement process. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with preferred implementation methods.

[0028] The three sets of data in Examples 1 and 4, and the third set of data in Examples 2 and 3 were all determined using the following method:

[0029] (1) Preparation steps: Place an empty quartz beaker in a muffle furnace and heat at 775 ± 25 °C for 20 min. Then, take out the quartz beaker and cool it for 3 min. Then, transfer it to a desiccator without desiccant and cool it to room temperature. Weigh it to the nearest 0.1 mg and record it as G0.

[0030] (2) Sample preparation steps: Before sampling, heat the oil slurry to 60°C and stir for 5 minutes;

[0031] (3) Sampling step: put the oil slurry in (2) into the beaker treated in step (1), and record the weight as G1;

[0032] (4) Ashing step: Place the oil slurry in the beaker on an electric furnace and continue heating for 1 hour until the residual material at the bottom is completely ashed;

[0033] (5) Burning step: Place the beaker heated in step (4) in a muffle furnace and heat at 775 ± 25 °C for 20 min. Then take it out and cool it for 3 min. Then transfer it to a desiccator without desiccant and cool it to room temperature. Weigh it to the nearest 0.1 mg and record it as G2.

[0034] (6) Calculate the solid content X in the oil slurry using the following formula:

[0035] Where ρ is the density of the oil slurry.

[0036] The difference between the measurement methods for the first and second groups of data in Examples 2 and 3 and the above-mentioned measurement method is that step (4) involves heating the oil slurry in the beaker on an electric furnace for 0.5 hours until the residual material at the bottom is completely ashed. This is due to the difference in sample size; when the oil slurry properties used are the same, the group with a smaller sample size also has a shorter ash time. A sample size of approximately 5g is recommended.

[0037] The oil slurry components used in the following examples are shown in Table 1:

[0038] Table 1 shows the properties of the slurry produced by the three catalytic units of Sinopec Jinling Petrochemical Co., Ltd.

[0039]

[0040]

[0041] The properties of the above three oil slurries used in this application are inconsistent and have great differences. The measurement method of this application can achieve good results in measuring the solid content of the above oil slurries, which also shows that the application range of this application is wide and can meet the solid content measurement needs of oil slurries of various properties.

[0042] Example 1

[0043] The slurry oil is produced by a catalytic device of Jinling Petrochemical Company

[0044] Three sets of data were measured using the steps in the above-mentioned measurement method, and the analysis results are shown in Table 2.

[0045] Table 2 Analysis data of slurry oil produced by catalytic unit

[0046]

[0047] As can be seen from the data in Table 2, the determination method adopted in this application has a short test time, a small relative error, a maximum error of 1.08%, and good accuracy.

[0048] Example 2

[0049] The slurry oil is produced by the second catalytic unit of Jinling Petrochemical Company

[0050] Three sets of data were measured using the steps in the above-mentioned measurement method, and the analysis results are shown in Table 3.

[0051] Table 3 is the analysis data of the slurry produced by the second catalytic unit

[0052]

[0053] As can be seen from the data in Table 3, the determination method adopted in this application has a short test time, a small relative error, a maximum error of 0.65%, and good accuracy.

[0054] Example 3

[0055] The slurry oil is produced by the three catalytic units of Jinling Petrochemical Company

[0056] Three sets of data were measured using the steps in the above-mentioned measurement method, and the analysis results are shown in Table 4.

[0057] Table 4 is the analysis data of the slurry produced by the three catalytic units

[0058]

[0059] As can be seen from the data in Table 4, the determination method adopted in this application has a short test time, a small relative error, a maximum error of 1.14%, and good accuracy.

[0060] Example 4

[0061] The slurry oil is produced by a catalytic device of Jinling Petrochemical Company

[0062] Three sets of data were measured using the steps in the above-mentioned measurement method, and the analysis results are shown in Table 5.

[0063] Comparative Example 1

[0064] The same slurry oil as in Example 4 was used to perform the determination according to the procedure of GBT 508-1985 for the determination of ash content in petroleum products. The results are shown in Table 5.

[0065] Comparative Example 2

[0066] The same slurry oil as in Example 4 was used to perform the test according to the test method in Example CN103196776B (extraction method). The results are shown in Table 5.

[0067] Table 5 is the oil slurry analysis data of Example 4 and Comparative Examples 1 and 2

[0068]

[0069] As shown in Table 5, the analysis results of the ash method used in Comparative Example 1 are essentially consistent with those of the present method. Furthermore, the present method has a shorter test time and a smaller relative error of only 0.74%. However, the results of the extraction method used in Comparative Example 2 differ significantly. During the extraction process, some small solid particles in the oil slurry passed through the filter paper and were not retained, affecting the analysis results. In summary, the present method offers a faster test speed and better accuracy.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A method for rapid determination of solid content in oil slurry, characterized in that: The steps include: (1) Preparation steps: Weigh the container and record the weight as G0; (2) Sample preparation steps: Heat and stir the oil slurry to ensure the representativeness of the sample; (3) Sampling step: put the oil slurry stirred in step (2) into the container treated in step (1), and record the weight as G1; (4) Ashing step: Continue to heat the oil slurry in the container until the residual material at the bottom of the container is completely ashed; (5) Burning step: Continue to heat the container after ashing in step (4) until the black oil gas on the upper part of the container is burned off, cool the container to dry, then cool it to room temperature, weigh it, and record the weight as G2; (6) Calculate the solid content X (g / L) in the oil slurry using the following formula: , where ρ is the density of the oil slurry (g / L).

2. The measuring method according to claim 1, wherein The steps in step (1) are as follows: heating the container at 775±25°C for 20 minutes, cooling the container in air for 3 minutes after taking it out, transferring it to a desiccator without desiccant and cooling it to room temperature, and weighing it with an analytical balance to an accuracy of 0.1 mg.

3. The measuring method according to claim 1, wherein In step (2), the oil slurry is heated to 60°C and stirred for at least 5 minutes.

4. The measuring method according to claim 1, wherein In step (4), electric furnace heating is adopted.

5. The measuring method according to claim 1, wherein The ashing time in step (4) is 0.5-1h.

6. The measuring method according to claim 1, wherein In step (5), a muffle furnace is used for heating at a temperature of 775±25°C for 20 min. The container is removed and cooled in air for 3 min, then transferred to a desiccant-free dryer and cooled to room temperature. The product is then weighed using an analytical balance with an accuracy of 0.1 mg.

7. The measuring method according to claim 1, wherein The container used is a high-temperature resistant quartz beaker.

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