A desolidification agent and a method for deeply removing solid content in catalytic cracking slurry oil

Abstract

The present application belongs to the technical field of fuel oil, and particularly relates to a desolidifying agent for removing solid content in oil slurry, and further discloses a method for deeply removing ash content in catalytic cracking oil slurry. The desolidifying agent has a unique removal effect on the solid ash contained in high-viscosity catalytic cracking oil slurry, especially the solid particles smaller than 20 microns, under the synergistic action of a main settling agent and a polymerization initiator, and has the advantages of high desolidifying efficiency, low energy consumption, simple operation, low running cost and high economic benefit.

Description

Technical Field

[0001] This invention belongs to the field of fuel oil technology, specifically relating to a desolventizing agent for pretreatment to remove solids from slurry oil, and further disclosing a method for deep removal of ash solids from catalytic cracking slurry oil. Background Technology

[0002] Catalytic cracking slurry is an offshoot of the catalytic cracking process. Due to its high content of short-chain polycyclic aromatic hydrocarbons, it is a high-quality raw material for producing high-value-added chemical products such as needle coke and carbon fiber. However, conventional catalytic cracking slurry typically contains more than 2 g / L of solid particles (mainly catalyst and coke powder), which severely limits its efficient utilization. Furthermore, when the slurry is used as heavy fuel oil, the solids in it can easily cause coking and wear on the burner nozzles. Therefore, it is necessary to remove solid particles from the slurry before application to ensure its performance. However, the catalyst particles in catalytic cracking slurry are mainly aluminum silicate (Al₂O₃·SiO₂) crystals with a particle size range of approximately 0-80 μm, especially particles smaller than 20 μm, which account for a considerable proportion. Because the catalyst powder in catalytic cracking slurry has a high density and a specific gravity close to that of the slurry, separating the catalyst from the slurry is quite difficult.

[0003] Currently, the catalytic slurry filtration processes commonly used in the industry mainly include traditional methods such as sedimentation, centrifugal separation, mechanical filtration, and electrostatic separation, with mechanical filtration being the most widely used. Mechanical filtration uses a metal material with tiny pores as a filter screen to remove fine solid particles contained in the slurry. However, as solid matter accumulates on the metal filter screen during filtration, the pressure drop during operation increases, requiring frequent screen replacements or increased backflushing frequency to meet filtration efficiency requirements. Therefore, mechanical filters typically suffer from intractable technological challenges such as easily damaged filter screens, short operating cycles, frequent switching of filtration modes, complex operation, and low filtration efficiency.

[0004] Therefore, developing a method for deep removal of ash solids from catalytic cracking slurry is of positive significance for the development and utilization of catalytic cracking slurry. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a desolidifying agent for pretreatment to remove solids from slurry, wherein the desolidifying agent can achieve sedimentation treatment of ash content in solids in catalytic cracking slurry;

[0006] The second technical problem to be solved by the present invention is to provide a method for deep removal of ash solids from catalytic cracking slurry, the method being able to achieve efficient sedimentation and purification of catalyst and other metal particles in catalytic slurry.

[0007] To solve the above-mentioned technical problems, the present invention provides a deconsolidation agent comprising a primary settling agent and a polymerization initiator;

[0008] The primary settling agent includes polyacrylamide;

[0009] The polymerization initiator includes organophosphorus compounds.

[0010] In the deconsolidation agent of this invention, the main settling agent is anionic polyacrylamide, whose molecular chain contains a certain amount of polar groups that can adsorb suspended solid particles in the slurry, causing bridging between particles to form large flocs, which can accelerate the sedimentation of particles in the suspension. The polymerization initiator is selected from organophosphorus substances, which act as ligands to catalytically couple with many heavy metals in the catalytic slurry, forming large molecular clusters that are more conducive to removal. Under the synergistic effect of the main settling agent and the polymerization initiator, the deconsolidation agent has a unique removal effect on solid ash contained in high-viscosity catalytic cracking slurry, especially solid particles smaller than 20 μm.

[0011] Specifically, the mass ratio of the primary settling agent to the polymerization initiator is 70-98:2-30.

[0012] Specifically, the mass ratio of the primary settling agent to the polymerization initiator is 80-96:4-20.

[0013] Specifically, the organophosphorus in the deconsolidation agent includes one or a mixture of several of the following: triphenylphosphine, diphenylphosphine chloride, di-tert-butylphenylphosphine, tri-tert-butylphosphine, tert-butyldiphenylphosphine, cyclohexyldiphenylphosphine, tricyclohexylphosphine, tri(o-tolyl)phosphine, or tri(p-tolyl)phosphine.

[0014] The present invention also discloses the application of the aforementioned desoldering agent in the field of deep removal of solids from catalytic cracking slurry.

[0015] The present invention also discloses a method for deep removal of solids from catalytic cracking slurry, comprising the steps of mixing the desoldering agent with the catalytic cracking slurry to be treated and allowing it to settle.

[0016] Specifically, in the method for deep removal of solids from catalytic cracking slurry, the amount of the solidifying agent added is 400-600 mg / kg based on the amount of the catalytic cracking slurry.

[0017] Specifically, in the method for deep removal of solids from catalytic cracking slurry, the temperature of the settling step is 80-100℃.

[0018] Specifically, the method for deep removal of solids from catalytic cracking slurry further includes a step of preheating the catalytic cracking slurry;

[0019] Preferably, the temperature of the preheating step is 50-70℃, and preferably, the preheating time is 10-20 minutes.

[0020] Specifically, the method for deep removal of solids from catalytic cracking slurry also includes the step of removing the upper 90% of the slurry for analysis and testing after settling.

[0021] The present invention also discloses a catalytic cracking slurry with deep solids removal prepared by the method.

[0022] The deconsolidation agent of this invention employs a synergistic combination of a primary settling agent and a polymerization initiator. The primary settling agent is anionic polyacrylamide, whose molecular chain contains a certain amount of polar groups that can adsorb suspended solid particles in the slurry, causing bridging between particles to form large flocs, thereby accelerating particle sedimentation in the suspension. The polymerization initiator is selected from organophosphorus compounds, which act as ligands to catalytically couple with many heavy metals in the catalytic slurry, forming large molecular clusters that are more conducive to removal. Under the synergistic effect of the primary settling agent and the polymerization initiator, the deconsolidation agent of this invention has a unique removal effect on solid ash contained in high-viscosity catalytic cracking slurry, especially solid particles smaller than 20 μm. It effectively solves the problem that it is difficult to separate solid particles in FCC slurry because about 90% of the solid particles are catalyst particles with small particle sizes (mostly concentrated within 20 μm). It has the advantages of high deconsolidation efficiency, low energy consumption, simple operation, low operating cost, and high economic benefits.

[0023] The method for deep removal of solid ash from catalytic cracking slurry of the present invention utilizes the deconsolidating agent to perform deep sedimentation treatment on the solid ash in the slurry. This method can achieve efficient sedimentation and purification of catalyst and other metal particles in the catalytic slurry. The solid ash content of the catalytic slurry after deconsolidation is no more than 100 ppm. Compared with traditional slurry sedimentation agents, this technology solves the problem of being unable to remove fine particles from heavy oil catalytic slurry. It is not affected by heavy components such as gums and asphaltenes in the slurry and has a high deconsolidation capacity for heavy oil catalytic slurry. This enables the originally difficult-to-treat and low-economic-value catalytic slurry to be converted into high-quality feedstock oil that can be used to develop marine fuel oil or needle coke. This lays the foundation for refineries to further process and explore the high-value applications of catalytic slurry and provides a new way for petroleum refining enterprises to utilize the external catalytic slurry, greatly improving the economic benefits of refining enterprises and reducing equipment operation and maintenance costs.

[0024] The method for deep removal of solid ash from catalytic cracking slurry of the present invention utilizes the deconsolidating agent to perform deep sedimentation treatment on the solid ash in the slurry. After the catalytic slurry is preheated, the deconsolidating agent is added and subjected to high-temperature sedimentation treatment. The solid content removal rate in the slurry can reach 90.76%, the viscosity of the slurry is reduced by 27%-40%, and the asphaltene removal rate reaches 59%-63%, effectively ensuring the properties of the slurry. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0026] In the following embodiments of the present invention, in order to minimize errors caused by instruments, equipment, and human operation, a uniform ground glass tube was used as the sedimentation container, with a height of 25cm and a volume of 100ml.

[0027] Example 1

[0028] In this embodiment, a settling agent consisting of a primary settling agent (polyacrylamide) and a polymerization initiator (triphenylphosphine) in different mass ratios was added for settling treatment. The specific addition ratios are shown in Table 1 below.

[0029] Weigh 500g of oil slurry into a 1000ml beaker. Preheat the oil slurry in a 60℃ water bath for 15 minutes. Add the corresponding deconsolidating agent at a ratio of 500mg / kg, stir manually for 1 minute, pour into a ground glass joint test tube, and place in a 90℃ water bath for constant temperature to begin the sedimentation test. After sedimentation for 48 hours, transfer the top 90% of the oil slurry for analysis and testing.

[0030] Among them, samples 1-12 were supplemented with 500 mg·kg⁻¹ -1 Samples with different ratios of settling agents: Sample 13 is a blank sample that was allowed to settle freely without the addition of settling agent, while Sample 14 is an oil slurry raw material that was not subjected to a settling test.

[0031] Testing revealed that the silicon content in the oil slurry raw material (No. 14) was 106.3 mg·kg⁻¹. -1 The aluminum content is 89.5 mg·kg. -1 The total amount is 195.8 mg·kg. -1 The analysis results of the samples after sedimentation test are shown in Table 1.

[0032] Table 1. Analysis of solid content removal rate of catalytic slurry after treatment with different ratios of deconsolidating agents.

[0033]

[0034] As shown in Table 1, sample No. 9 had the highest overall removal rate of 90.76%. Compared with the blank sedimentation sample, the removal efficiency of the sedimentation removal treatment by adding a deconsolidating agent in this invention can be improved by 15.9%; compared with the removal method of adding only the main sedimentation agent, the removal efficiency can be improved by 19.92%; and compared with the removal method of adding only the polymerization initiator, the removal efficiency can be improved by 21.81%.

[0035] Example 2

[0036] This embodiment further investigates the effect of settling time on the ash removal method for solids in catalytic cracking slurry. To better examine the removal effect of the slurry settling agent, the deconsolidating agent used in this embodiment is sample No. 9 from Example 1, which includes a main settling agent (polyacrylamide) and a polymerization initiator (triphenylphosphine) in a mass ratio of 96:4.

[0037] Evaluation method for oil slurry settling agent: Weigh 500g of oil slurry (same as sample 14 in Example 1) into a 1000ml beaker. Preheat the weighed oil slurry in a 60℃ water bath for 15 minutes, and add 500mg·kg⁻¹. -1 The corresponding oil slurry settling agent was manually stirred for 1 minute, poured into a test tube, and placed in a 90℃ water bath for constant temperature to begin the settling test. The upper 90% of the oil slurry was collected for analysis and testing according to different settling times as described in Table 2. The results of the analysis of the changes in silicon and aluminum content with settling time are shown in Table 2 below.

[0038] Table 2 Results of the Settlement Time Test

[0039] Settling time / h <![CDATA[(Al + Si) / mg·kg -1 > Removal rate, % 0 195.8 0 24 108.9 44.38 48 18.9 90.34 72 18.3 90.65 96 17.5 91.06 120 17.2 91.21 144 16.9 91.36 168 16.7 91.47

[0040] As can be seen from the data in Table 2, the removal rate of aluminum and silicon content in the oil slurry gradually increases with the extension of time during the sedimentation process. The removal rate increases the fastest within 48 hours, and then the increase slows down.

[0041] Example 3

[0042] In order to better control the operating cost of adding the stripping agent, this embodiment examines the trend of the dosage of the stripping agent and the aluminum and silicon content of the oil slurry after stripping.

[0043] Weigh 500g of oil slurry (same as sample oil slurry No. 14 in Example 1) into a 1000ml beaker. Preheat the weighed oil slurry in a 60℃ water bath for 15 minutes, add the corresponding amount of deconsolidating agent (same as in Example 2) as shown in Table 3 below, stir manually for 1 minute, pour into a test tube, place in a 90℃ water bath for constant temperature, and begin the sedimentation test.

[0044] After 48 hours of settling, 90% of the top slurry was collected for analysis. The results are shown in Table 3.

[0045] Table 3 Results of the investigation on the amount of flocculant added

[0046]

[0047]

[0048] As can be seen from the data in Table 3, when the dosage of the deconsolidating agent exceeds 500 mg / kg... -1 The decline in aluminum and silicon content has slowed down. Considering operating costs, a dosage of 500 mg / kg is recommended. -1 .

[0049] Example 4

[0050] This embodiment is used to investigate the removal effect of different asphalt slurries and the changes in slurry properties.

[0051] Weigh 500g of oil slurry with different asphaltene contents into a 1000ml beaker. Preheat the weighed oil slurry in a 60℃ water bath for 15 minutes, and add 500mg·kg⁻¹ of oil slurry. -1 The deconsolidating agent (same as in Example 2) was manually stirred for 1 minute, poured into a test tube, and placed in a 90°C water bath for constant temperature to begin the settling test. After 48 hours of settling, 90% of the upper part of the slurry was taken for analysis. The results of asphalt removal from the slurry are shown in Table 4 below.

[0052] Table 4. Investigation of asphaltene content after the addition of settling agent.

[0053] Pre-desorption asphalt content of oil slurry / % Asphalt content after degreasing / % Asphalt removal rate / % 1.15 0.42 63 1.31 0.54 59 1.28 0.52 59 1.35 0.56 59 1.67 0.69 59

[0054] It can be seen that by adding the deconsolidating agent described in this invention to the oil slurry for sedimentation treatment, the asphaltene removal rate in the oil slurry is 59-63%, which can solve the influence of heavy components such as gum and asphaltene in the oil slurry and has a high deconsolidation capacity for heavy oil catalytic oil slurry.

[0055] Example 5

[0056] This embodiment is used to investigate the removal effect of oil slurry of different viscosities and the changes in oil slurry properties.

[0057] Weigh 500g of oil slurry of different viscosities into a 1000ml beaker. Preheat the weighed oil slurry in a 60℃ water bath for 15 minutes, then add 500mg·kg⁻¹ of oil. -1 The deconsolidating agent (same as in Example 2) was manually stirred for 1 minute, poured into a test tube, and placed in a 90°C water bath for constant temperature to begin the sedimentation test. After 48 hours of sedimentation, 90% of the upper part of the oil slurry was taken for viscosity analysis. The results of the viscosity change are shown in Table 5 below.

[0058] Table 5. Investigation of oil slurry viscosity after addition of flocculant.

[0059] <![CDATA[Viscosity of slurry before stripping, 50℃ mm 2 / s]]> <![CDATA[Viscosity of slurry after stripping, 50℃ mm 2 / s]]> Oil slurry viscosity reduction rate, / % 412 296 28 407 244 40 289 210 27 356 260 27 388 283 27 388 285 27

[0060] It can be seen that by adding the deconsolidating agent described in this invention to the oil slurry for sedimentation treatment, the viscosity of the oil slurry is reduced by 27%-40%, which can solve the influence of heavy components such as gum and asphalt in the oil slurry and has a high deconsolidation capacity for heavy oil catalytic oil slurry.

[0061] Example 6

[0062] This embodiment is used to investigate the effect of the change in oil slurry viscosity after the addition of the aforementioned deconsolidating agent on the removal rate.

[0063] In a 1000ml beaker, 500g of oil slurry A and oil slurry B were weighed out respectively. Oil slurry A had a viscosity of 645 mmHg. 2 / s (50℃), the viscosity of slurry B is 376 mm. 2 / s (50℃).

[0064] Preheat the weighed oil slurry in a 60℃ water bath for 15 minutes, then add 500 mg·kg⁻¹. -1 The corresponding settling agent (same as in Example 2) was manually stirred for 1 minute, poured into a test tube, and placed in a 90°C water bath for constant temperature to begin the sedimentation test. After 48 hours of sedimentation, 90% of the upper part of the oil slurry was collected for viscosity analysis.

[0065] The effect of the change in viscosity of the oil slurry after sedimentation treatment on the removal rate is shown in Table 6 below.

[0066] Table 6. Effect of changes in slurry viscosity after addition of flocculant on removal rate.

[0067]

[0068]

[0069] As can be seen from the data in Table 6, although the viscosity of oil slurry A is about twice that of oil slurry B, the removal rate of oil slurry does not change much after the addition of this settling agent. Therefore, this settling agent solves the problem of not being able to remove fine particles from heavy oil catalytic oil slurry. It is not affected by heavy components such as gums and asphalt in the oil slurry and has a high desolidification ability for heavy oil catalytic oil slurry.

[0070] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for deep removal of solids and asphaltenes from catalytic cracking slurry while simultaneously reducing slurry viscosity, characterized in that, The process includes the steps of mixing a deconsolidating agent with the catalytic cracking slurry to be treated and allowing it to settle; the deconsolidating agent consists of a main settling agent and a polymerization initiator; The primary settling agent is polyacrylamide; The polymerization initiator is an organophosphorus; The mass ratio of the main settling agent to the polymerization initiator is 90-98:2-10; The organophosphine is selected from one or a mixture of several of triphenylphosphine, diphenylphosphine chloride, di-tert-butylphenylphosphine, tri-tert-butylphosphine, tert-butyldiphenylphosphine, cyclohexyldiphenylphosphine, tricyclohexylphosphine, tris(o-tolyl)phosphine, and tris(p-tolyl)phosphine; the amount of the deconsolidating agent added is 500-600 mg / kg based on the amount added to the catalytic cracking slurry.

2. The method for deep removal of solids and asphaltenes from catalytic cracking slurry and simultaneous reduction of slurry viscosity according to claim 1, characterized in that, The temperature for the settling step is 80-100℃.

3. The method for deep removal of solids and asphaltenes from catalytic cracking slurry and simultaneous reduction of slurry viscosity according to claim 1, characterized in that, The method further includes a step of preheating the catalytic cracking slurry; the temperature of the preheating step is 50-70°C.

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