Method for improving utilization of slurry by removing solid

Abstract

The application relates to the technical field of petroleum processing, and particularly discloses a solid-removing method for improving the utilization rate of oil slurry. The method comprises the following steps: (1) performing membrane separation on oil slurry raw materials to obtain clarified oil slurry and concentrated oil slurry, wherein the pore size of the membrane is less than 0.2 mu m; (2) contacting an extractant and the concentrated oil slurry to perform extraction, so as to obtain an upper raffinate phase and a lower extract phase; (3) performing solid removal on the raffinate phase to obtain solid-containing raffinate oil; and removing the extractant from the extract phase, so as to separate the extractant and extract oil, return the extractant to step (2) to perform extraction, and return the extract oil to step (1) to perform separation. The solid-removing method improves the solid-removing efficiency of the whole process, can achieve the purpose of deep solid removal, and the whole oil slurry deep solid removal process is basically free of by-products.

Description

Technical Field

[0001] This invention relates to the field of petroleum processing technology, and more specifically to a desoldering method for improving the utilization rate of oil slurry. Background Technology

[0002] In the field of petroleum processing technology, slurry oil is an important byproduct, mainly derived from secondary processing of crude oil, such as catalytic cracking and delayed coking. Slurry oil contains a large amount of tri- and tetra-cyclic aromatic hydrocarbons, making it an ideal component for preparing carbon material precursors. However, solid particles in the slurry oil, such as catalyst powder, can affect its comprehensive utilization. Therefore, how to effectively remove solid particles from slurry oil and improve its comprehensive utilization value is a pressing problem in the current petroleum processing technology field.

[0003] Existing oil slurry desolidification technologies mainly include filtration and sedimentation. In addition, there are some enhancement methods, such as vacuum, centrifugation, pressure filtration, centrifugal sedimentation, electric fields, and magnetic fields. Two or more liquid-solid separation methods can also be combined to improve filtration speed and efficiency. In recent years, technologies that can achieve continuous desolidification include cross-flow membrane filtration, electric field desolidification, and gravity-assisted desolidification.

[0004] CN110747006A discloses a method for removing solid impurities from catalytic oil slurry. This method includes an oil-catalyst mixing unit, a centrifugal deasphalting unit, a light oil slurry filtration unit, a light oil slurry solvent removal unit, and a heavy oil slurry solvent removal unit. The catalytic oil slurry and solvent are thoroughly mixed. Based on the different solubilities of the solvent for each component of the oil slurry, asphaltenes are removed from the oil slurry by centrifugation, reducing the impact of asphaltenes on oil slurry filtration, improving the reliability of oil slurry filtration, and ensuring the long-term stable operation of the oil slurry filtration system. The solvent is recovered and recycled through the light and heavy oil slurry solvent removal units, reducing solvent consumption. However, this technology does not further process the heavy components rich in solids and the asphaltenes, treating them as low-value byproducts, resulting in low overall utilization of the oil slurry.

[0005] Although existing oil slurry desolidification technologies have solved the problem of removing solid particles from oil slurries to some extent, they still have some problems and drawbacks. First, oil slurries have high viscosity, with ash content typically ranging from 2000 to 5000 ppm. The solid particles have a wide size distribution and complex and variable properties, with particle sizes concentrated between 0.5 and 40.0 μm. Currently, no single technology can deeply remove solid particles across such a wide size range. Second, existing technologies, while removing solid particles, also remove some useful oil slurry components, namely aromatic hydrocarbons, resulting in low utilization of the effective components in the oil slurry. Finally, existing technologies have short operating cycles and high energy consumption, which is not conducive to large-scale industrial applications. Summary of the Invention

[0006] The purpose of this invention is to provide a desolidification method to improve the utilization rate of oil slurry. This desolidification method can effectively remove solids with a wide range of particle sizes in the oil slurry, achieving the purpose of deep desolidification. It does not require an excessively high single-pass clarified oil slurry recovery rate, thereby reducing the circulation ratio and time, and improving the overall desolidification efficiency of the process. Overall, the deep desolidification process of oil slurry has virtually no by-products. The discharged components are mainly solid particles and saturated components, among which the aromatic components, which can be used as key components for the subsequent production of needle coke and other products, are almost entirely recycled back into the process and eventually enter the clarified oil slurry product.

[0007] This invention provides a method for improving the utilization rate of oil slurry by desolidification. The method includes: (1) performing membrane separation on the oil slurry raw material to obtain clarified oil slurry and concentrated oil slurry, wherein the pore size of the membrane is less than 0.2 μm; (2) contacting the extractant and the concentrated oil slurry for extraction to obtain an upper raffinate phase and a lower extractable phase; (3) desolidifying the raffinate phase to obtain raffinate oil containing solids; removing the extractant from the extractable phase to separate the extractant and the extractable oil, returning the extractant to step (2) for extraction, and returning the extractable oil to step (1) for separation.

[0008] Compared with existing technologies, the beneficial effects of this technical solution are as follows: 1. Through the combination of membrane filtration desolidification and extraction units, solids with a wide particle size range in the oil slurry can be effectively removed, achieving the purpose of deep desolidification. 2. The filtration unit does not need to pursue an excessively high clarified oil slurry recovery rate, thereby reducing the circulation ratio and time, and improving the overall process efficiency. 3. After the concentrated oil slurry is separated from the raw material, it is extracted to remove the solids and saturated components, and then returned to the filtration unit to become a clarified oil slurry. No concentrated oil slurry is produced in the whole process. 4. The solid catalyst particles and saturated fractions after extraction can be recycled into the catalytic cracking unit, solving the problem of their disposal. 5. Overall, the deep desolidification process of the oil slurry produces no concentrated oil slurry, realizing the comprehensive utilization of all components of the oil slurry. Moreover, the desolidification process is energy-saving and consumption-reducing, and the equipment has a long operating cycle. Attached Figure Description

[0009] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0010] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0011] This invention provides a method for improving the utilization rate of oil slurry by desolidification. The method includes: (1) performing membrane separation on the oil slurry raw material to obtain clarified oil slurry and concentrated oil slurry, wherein the pore size of the membrane is less than 0.2 μm; (2) contacting the extractant and the concentrated oil slurry for extraction to obtain an upper raffinate phase and a lower extractable phase; (3) desolidifying the raffinate phase to obtain raffinate oil containing solids; removing the extractant from the extractable phase to separate the extractant and the extractable oil, returning the extractant to step (2) for extraction, and returning the extractable oil to step (1) for separation.

[0012] According to a preferred embodiment of the present invention, in step (1), the pore size of the membrane is 0.1-0.2 μm, for example, 0.12 μm, 0.14 μm, 0.16 μm, 0.18 μm, etc. The aforementioned technical solution has the advantages of ensuring that the particle size distribution in the clarified oil slurry passing through the membrane pores meets product requirements, while preventing excessively low oil slurry permeability due to excessively small pore size, thereby reducing the throughput of the extraction unit and the energy consumption of the entire process system.

[0013] In this invention, there are no special requirements for the single-pass throughput of the clarified oil slurry. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the single-pass throughput of the clarified oil slurry is 70-90%, for example, 72%, 75%, 78%, 80%, 82%, 85%, 88%, etc.

[0014] In this invention, there are no special restrictions on the specific control method for controlling the single-pass throughput of the clarified slurry. For example, it can be controlled by adjusting the pressure, which is well known to those skilled in the art and will not be elaborated here.

[0015] In this invention, no special requirements are made for the specific method of membrane filtration. For example, cross-flow membrane filtration can be used for membrane filtration.

[0016] In this invention, there are no special requirements for the solid content of the oil slurry raw material being processed. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the solid content of the oil slurry raw material is 1800-6000 ppm.

[0017] In this invention, there are no special requirements for the source of the oil slurry feedstock. The embodiments of this invention exemplify the advantages of this invention by using catalytic cracking oil slurry as the feedstock, but do not limit the scope of this invention.

[0018] In this invention, there are no special requirements for the content of each component in the oil slurry raw material. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the oil slurry raw material contains, by weight: 15-65% saturated components, 25-65% aromatic components, 8-20% gum, and 1-8% asphaltene.

[0019] In this invention, in step (2), there are no special requirements for the specific device for extraction. It can be a stirring tank or an extraction tower. In this embodiment of the invention, the extraction is carried out in an extraction tower to illustrate the advantages of the invention. There are no special requirements for the internal structure of the extraction tower. For example, the extraction tower can have static or dynamic internal components. The static internal components can be a turntable and / or a sieve plate, and the dynamic internal components can be a vibrating sieve plate and / or a turbine.

[0020] In this invention, there are no special requirements for the ratio of the extractant to the concentrated oil slurry in step (2). The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the mass ratio of the extractant to the concentrated oil slurry is (0.5-3):1, for example, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, etc.

[0021] In this invention, there is no special limitation on the specific type of extractant in step (2). The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the extractant is selected from one or more of furfural, DMF, N-methylpyrrolidone, dimethyl sulfoxide and sulfolane.

[0022] According to a preferred embodiment of the present invention, the density of the extractant is less than the density of the concentrated oil slurry. Using the aforementioned technical solution, better extraction can be achieved. After the concentrated oil slurry comes into contact with the extractant, it releases saturated components with low solubility and low density, which carry solid particles and move towards the top of the column. Meanwhile, the aromatic components, colloids, and asphaltenes with high density and high polarity in the oil slurry are dissolved and carried towards the bottom of the column. During the upward movement of the raffinate, it comes into countercurrent contact with the fresh extractant, dissolving the small amount of aromatic components it carries and moving towards the bottom of the column, thus improving the selectivity of the extraction.

[0023] In this invention, the extraction temperature can be selected over a wide range. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the extraction temperature is 25-130°C, preferably 40-60°C.

[0024] In this invention, there are no special requirements for the extraction time. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the extraction time is 10-60 min.

[0025] According to a preferred embodiment of the present invention, during the extraction process, the extractant and the concentrated oil slurry are in countercurrent contact. The entry points of the concentrated oil slurry and the extractant into the extraction tower are determined by their densities; the denser fluid enters from the upper side of the tower, while the less dense fluid enters from the lower side, achieving countercurrent contact within the tower. During this process, the extractant breaks down the inclusions formed by the polar adsorption of colloids, asphaltenes, and catalyst powder, releasing the catalyst powder. The saturated fraction in the concentrated oil slurry has low solubility and low density with the extractant, and is distributed in the upper layer, but has high viscosity, trapping most of the catalyst powder, especially small particles, within it; a small amount of larger particles settle into the lower extraction phase.

[0026] In this invention, there are no special requirements for the temperature of the raffinate desolidation in step (3). According to a preferred embodiment of this invention, the temperature of the raffinate desolidation is not higher than the temperature of the extraction, and is more preferably 0-60℃.

[0027] In this invention, there are no special requirements for the time of desolidation of the raffinate phase in step (3). The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the time of desolidation of the raffinate phase is 0.5-4h.

[0028] According to a preferred embodiment of the present invention, in step (3), the deconsolidation of the raffinate phase is carried out in a settling separator with a narrowed bottom diameter. The advantages of the present invention are illustrated in this embodiment using a settling tank with a narrowed bottom diameter. The settling separator with a narrowed bottom diameter facilitates the release of the catalyst powder that has been settling, and a differential pressure level gauge can be used to control the interface, automatically opening the bottom valve to release the catalyst powder settling at the bottom of the separator based on the density difference.

[0029] In this invention, the destination of the raffinate phase can be handled differently depending on the composition and structure of the saturated fractions in the concentrated slurry. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, when the saturated fractions in the concentrated slurry are mainly alkanes, the raffinate phase is returned to the catalytic cracking unit for reprocessing by stripping distillation or vacuum distillation; when the saturated fractions in the concentrated slurry are mainly cycloalkanes, the raffinate phase is mixed with the extracted phase for subsequent processing.

[0030] In this invention, the method for removing the extractant from the extraction phase in step (3) is not specifically limited. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the method for removing the extractant from the extraction phase is selected from one or more of flash distillation, vacuum distillation, stripping distillation, and molecular distillation. In this embodiment of the invention, flash distillation is used as the method for removing the extractant from the extraction phase to illustrate the advantages of the invention.

[0031] According to a preferred embodiment of the present invention, the operating system of the present invention includes: a filtration unit, an extraction unit, a recovery unit, and a sedimentation unit; The filtration unit is used for membrane separation; The extraction unit is used for contact extraction of the extractant and the concentrated oil slurry; The recovery unit is used to remove the extractant from the extraction phase; The settling unit is used for the deconsolidation of the raffinate phase.

[0032] The present invention will be described in detail below through embodiments.

[0033] In the following embodiments, The solid content was determined according to GB / T508-85 "Determination of Ash Content in Petroleum Products"; a solid content of less than 100 ppm in the product is considered to meet the standard. The composition of the solid residue oil was analyzed by gas chromatography-mass spectrometry in accordance with NB / SH / T0509-2010 "Determination of Four Components of Petroleum Asphalt". Furfural is a commercially available reagent-grade (99%) product from McLean, brand name MKL-F809410. DMF is a commercially available analytical grade (99.5%) product from McLean Company, brand name M23417. In this embodiment of the invention, both oil slurry feedstock 1 and oil slurry feedstock 2 are catalytic cracking oil slurries, wherein, Oil slurry feedstock No. 1 (solid content 3120 ppm) contains 20.17 wt% saturated matter, 61.27 wt% aromatic matter, 15.42 wt% 8-20% resin, and 3.14 wt% 1-8% asphaltene; the solid content is 3120 ppm. In oil slurry raw material No. 2 (solid content of 2150 ppm), the content of saturated matter is 63.73 wt%, the content of aromatic matter is 18.66 wt%, the content of resin is 16.27 wt%, and the content of asphaltenes is 1.34 wt%.

[0034] Example 1 according to Figure 1The process flow involves feeding oil slurry raw material No. 1 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 70% by adjusting the feed pressure, and the membrane pore size is 0.1μm.

[0035] Furfural and concentrated oil slurry (density 1.0182 g / cm³) were injected into a turbine extraction tower at a ratio of 0.5:1. Furfural entered through the top inlet of the extraction tower, while the concentrated oil slurry entered through the bottom, resulting in countercurrent contact within the tower. The extraction tower temperature was set at 40℃, and the extraction time was set at 10 min. The resulting raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank, where it settled at 40℃ for 0.5 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. This raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered a recovery unit, where the extractant was removed by flash evaporation to obtain an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration, resulting in a clarified oil slurry that was rich in aromatics and deeply desolidified.

[0036] The final product, clarified oil slurry, has a solid content of 37.6 ppm and a total yield of 90%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.43 kg.

[0037] Example 2 according to Figure 1 The process flow involves feeding oil slurry raw material No. 1 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 80% by adjusting the feed pressure, and the membrane pore size is 0.15μm.

[0038] DMF (dimethylaminomethyl methacrylate) and concentrated oil slurry (density 1.0182 g / cm³) were injected into a turbine extraction tower at a 1:1 ratio. DMF entered through the lower inlet of the extraction tower, while the concentrated oil slurry entered through the upper inlet, and the two phases were contacted countercurrently within the tower. The extraction tower temperature was set at 50°C, and the extraction time was set at 30 min. The resulting raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank, where it was settling at 50°C for 1 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. Therefore, the raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered the recovery unit, where the extractant was removed by flash evaporation to obtain an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration, resulting in a clarified oil slurry that was enriched in aromatics and deeply desolidified.

[0039] The final product, clarified oil slurry, has a solid content of 42.3 ppm and a total yield of 95%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.25 kg.

[0040] Example 3 according to Figure 1 The process flow involves feeding oil slurry raw material No. 1 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 90% by adjusting the feed pressure, and the membrane pore size is 0.2μm.

[0041] DMF (dimethylaminomethyl methacrylate) and concentrated oil slurry (density 1.0182 g / cm³) were injected into a turbine extraction tower at a ratio of 2:1. DMF entered through the lower inlet of the extraction tower, while the concentrated oil slurry entered through the upper inlet, and the two phases were contacted countercurrently within the tower. The extraction tower temperature was set at 60℃, and the extraction time was set at 30 min. The resulting raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank, where it was settling at 60℃ for 0.5 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. This raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered the recovery unit, where the extractant was removed by flash evaporation to obtain an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration to obtain a clarified oil slurry that was rich in aromatics and deeply desolidified.

[0042] The final product, clarified oil slurry, has a solid content of 58.9 ppm and a total yield of 98%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.1 kg.

[0043] Example 4 according to Figure 1 The process flow involves feeding oil slurry raw material No. 2 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 70% by adjusting the feed pressure, and the membrane pore size is 0.1μm.

[0044] Furfural and concentrated oil slurry (density 0.956 g / cm³) were injected into a turbine extraction tower at a mass ratio of 0.5:1. Furfural entered through the top inlet of the extraction tower, while the concentrated oil slurry entered through the bottom, and the two phases were contacted countercurrently within the tower. The extraction tower temperature was set at 40℃, and the extraction time was set at 10 min. The raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank, where it was settling at 40℃ for 1 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. Therefore, the raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered the recovery unit, where the extractant was removed by flash evaporation to obtain an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration to obtain a clarified oil slurry that was rich in aromatics and deeply desolvated.

[0045] The final product, clarified oil slurry, has a solid content of 26.8 ppm and a total yield of 90%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.43 kg.

[0046] Example 5 according to Figure 1 The process flow involves feeding oil slurry raw material No. 2 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 80% by adjusting the feed pressure, and the membrane pore size is 0.15μm.

[0047] DMF (dimethylaminomethyl ether) and concentrated oil slurry (density 0.956 g / cm³) were injected into a turbine extraction tower at a 1:1 ratio. DMF entered through the lower inlet of the extraction tower, while the concentrated oil slurry entered through the upper inlet, resulting in countercurrent contact within the tower. The extraction tower temperature was set at 50°C, and the extraction time was set at 30 min. The resulting raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank at 50°C for 0.5 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. This raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered the recovery unit, where flash evaporation removed the extractant, resulting in an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration, yielding an aromatic-enriched and deeply desolidified clarified oil slurry.

[0048] The final product, clarified oil slurry, has a solid content of 37.8 ppm and a total yield of 95%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.25 kg.

[0049] Example 6 according to Figure 1 The process flow involves feeding oil slurry raw material No. 2 into a cross-flow membrane filtration device to obtain clarified oil slurry and concentrated oil slurry. The single-pass throughput of the clarified oil slurry is maintained at 90% by adjusting the feed pressure, and the membrane pore size is 0.2μm.

[0050] DMF (dimethylaminomethyl methacrylate) and concentrated oil slurry (density 0.956 g / cm³) were injected into a turbine extraction tower at a ratio of 2:1. DMF entered through the lower inlet of the extraction tower, while the concentrated oil slurry entered through the upper inlet, and the two phases were contacted countercurrently within the tower. The extraction tower temperature was set at 60℃, and the extraction time was set at 30 min. The resulting raffinate and extractable phases were obtained. The raffinate entered a bottom-constricted settling tank, where it was settling at 60℃ for 1.5 h. After settling, it separated into an upper layer of raffinate containing solids and a lower layer containing a large amount of solid particles. Analysis of the composition of the raffinate containing solids revealed that the saturated fraction was mainly alkanes. This raffinate containing solids can be returned to the catalytic cracking unit for reprocessing after stripping distillation or vacuum distillation, while the lower layer is discharged. The extractable phase entered the recovery unit, where the extractant was removed by flash evaporation to obtain an aromatic-enriched extractable oil (containing a small amount of solid particles). This extractable oil was then returned to a cross-flow membrane filtration unit for secondary filtration to obtain a clarified oil slurry that was rich in aromatics and deeply desolidified.

[0051] The final product, clarified oil slurry, has a solid content of 51.2 ppm and a total yield of 98%. The membrane filtration capacity corresponding to 1 kg of clarified oil slurry product is 1.1 kg.

[0052] Comparative Example 1 The method of Example 1 is different except that the cross-flow membrane filter has a pore size of 0.3 μm, and the solid content in the clarified oil slurry of the final product is 328 ppm, which does not meet the requirements of subsequent products for the solid content in the raw materials.

[0053] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for improving the utilization rate of oil slurry, characterized in that, The method includes: (1) The oil slurry raw material is subjected to membrane separation to obtain clarified oil slurry and concentrated oil slurry, wherein the pore size of the membrane is less than 0.2 μm; (2) Extraction is carried out by contacting the extractant with the concentrated oil slurry to obtain the upper raffinate phase and the lower extract phase; (3) The raffinate phase is desolidified to obtain raffinate oil containing solids; the extractant is removed from the extract phase, and the extractant and extract oil are separated. The removed extractant is returned to step (2) for extraction, and the extract oil is returned to step (1) for separation.

2. The deconsolidation method according to claim 1, characterized in that, In step (1), The membrane has a pore size of 0.1-0.2 μm; and / or The single-pass throughput of clarified oil slurry is 70-90%.

3. The deconsolidation method according to claim 1 or 2, characterized in that, The solid content of the oil slurry raw material is 1800-6000 ppm; and / or The slurry feedstock is selected from catalytic cracking slurry.

4. The deconsolidation method according to claim 1 or 2, characterized in that, By weight, the oil slurry raw material comprises: 15-65% saturated components, 25-65% aromatic components, 8-20% gum, and 1-8% asphaltenes.

5. The deconsolidation method according to claim 1 or 2, characterized in that, In step (2), the mass ratio of extractant to concentrated oil slurry is (0.5-3):

1.

6. The deconsolidation method according to claim 1 or 2, characterized in that, In step (2), the extractant is selected from one or more of furfural, DMF, N-methylpyrrolidone, dimethyl sulfoxide and sulfolane.

7. The deconsolidation method according to claim 6, characterized in that, In step (2), the density of the extractant is less than the density of the concentrated oil slurry.

8. The deconsolidation method according to claim 1 or 2, characterized in that, In step (2), the extraction conditions include: Temperatures range from 25 to 130°C; and / or The time is 10-60 minutes; and / or The contact method is countercurrent contact.

9. The deconsolidation method according to claim 8, characterized in that, In step (3), the extraction temperature is 40-60℃.

10. The deconsolidation method according to claim 1 or 2, characterized in that, In step (3), the conditions for the removal of the raffinate phase include: The temperature shall not exceed the extraction temperature; and / or The time is 0.5-4 hours.

11. The deconsolidation method according to claim 10, characterized in that, In step (3), the temperature for the desolidification of the raffinate phase is 0-60℃.

12. The deconsolidation method according to claim 1 or 2, characterized in that, In step (3), the desolidification of the raffinate phase is carried out in a sedimentation separator with a narrowed bottom diameter.

13. The deconsolidation method according to claim 1 or 2, characterized in that, In step (3), The saturated fraction in the concentrated slurry is mainly alkanes, and the residual oil is returned to the catalytic cracking unit for reprocessing by stripping distillation or vacuum distillation; or The saturated fraction in the concentrated oil slurry is mainly cycloalkanes, and the raffinate is mixed with the extraction phase for further processing.

14. The deconsolidation method according to claim 1 or 2, characterized in that, In step (3), the method for removing the extractant from the extraction phase is selected from one or more of flash distillation, vacuum distillation, stripping distillation and molecular distillation.

Images