A method for reducing solid content in catalytic cracking slurry

Abstract

A method for reducing the solid content in catalytic cracking slurry comprises: (1) mixing an auxiliary agent with raw oil and heating it to obtain a raw oil liquid, wherein the auxiliary agent is petroleum wax with a carbon number between C20 and C43 and a normal paraffin mass content of 35 to 60%; (2) mixing a diluent with the raw oil liquid in step (1), cooling to obtain a liquid-solid mixture, and performing solid-liquid separation to obtain a desolidified oil liquid and a wax paste, wherein the diluent is a C3-C6 fatty ketone and / or a C6-C8 aromatic hydrocarbon; (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking slurry desolidified with solids, and removing the diluent from the wax paste to obtain the auxiliary agent containing solids. The method provided by the present invention has simple steps, and the solid removal rate of the catalytic cracking slurry is greater than 88%.

Description

Technical Field

[0001] The present invention relates to a method for separating solid matter from hydrocarbon oil, and in particular to a method for reducing the solid matter content in a heavy oil catalytic reaction product by using a filtration separation method. Background Art

[0002] Catalytic cracking slurry oil is the fraction of the catalytic reaction that is not fully converted to light oil products and is difficult to crack. The reaction products extracted from the distillation column bottoms are partially recycled and blended, with the remaining fraction discharged from the unit to maintain the unit's thermal balance and processing capacity. This portion of slurry oil discharged from the unit is generally referred to as "spilt slurry oil" and is characterized by a wide distillation range, high density, high aromatics and resin content, and asphaltenes. The various components of catalytic cracking slurry oil can be used as blending components for heavy fuel oil, as well as raw materials for the production of carbon black, petroleum coke, and for aromatics extraction to produce rubber additives or asphalt softeners, offering significant application value and promising prospects. The primary factor limiting the high-value utilization of slurry oil is the presence of catalyst fines in the catalytic cracking slurry oil. This content, determined by the slurry oil solids content method, typically ranges from 0.1% to 0.7%, with some even reaching 1%. When catalytic cracking slurry oil is used directly as a blending component for heavy fuel oil, the catalyst fines it contains can settle and accumulate in storage tanks and pipelines, causing blockages. The high-pressure, high-velocity flow of catalyst fines can also cause nozzle wear. When used as a raw material for carbon black or coking, the solid content must meet certain feed standards, otherwise it will be difficult to produce high-quality products. Therefore, it is necessary to remove the catalyst powder from the catalytic oil slurry in order to utilize the catalytic oil slurry at a high value.

[0003] The existing methods for removing catalyst powder from catalytic cracking oil slurry mainly include gravity sedimentation, filtration separation, centrifugal separation and electrostatic separation. One of the gravity sedimentation methods is to store the catalytic oil slurry at a certain temperature to achieve the purpose of separating the catalyst powder, but the separation time is long and the efficiency is low. In order to increase the sedimentation rate of the catalyst powder, a polymer with a relatively large molecular weight can be added to form a stronger interface affinity, reduce the dispersion stability between the particles, and aggregate into large flocculent objects, which can achieve the purpose of accelerating the sedimentation rate of the catalyst powder. The filtration separation method uses a filter medium to intercept the catalyst powder in the catalytic oil slurry to achieve the purpose of removing the catalyst powder. The key to the technology is to select a suitable filter medium, and the filter medium has good regeneration performance and can operate stably for a long time. Centrifugal separation is a method of separating catalyst powder in the oil slurry by strengthening the effect of the gravity field. It has a good desolidification effect, but has high energy consumption and low processing capacity, and is difficult to match with the continuous production of catalytic cracking. The electrostatic separation method is to polarize the catalyst powder in a fluidized state and adsorb it onto the electrode plate under the action of a high-voltage electric field, thereby achieving the purpose of separating the catalyst powder from the catalytic oil slurry. Due to the existence of competitive adsorption, the adaptability of electrostatic separation technology is poor. The key to this technology is to develop targeted technical solutions based on the properties of different raw oils.

[0004] CN1239135A discloses a method for separating catalyst particles from catalytic cracking oil slurry. This method connects three filtering devices in parallel and separates the catalyst solid particles from the oil slurry through filtration, backwashing, dilution, and other steps. However, there are problems with rapid filter failure and easy clogging of the filter material. CN101633849A discloses a method for removing catalyst powder from catalytic cracking oil slurry. This method adds a solid separation agent to the catalytic oil slurry, mixes it evenly, and then filters and separates it to obtain the oil slurry free of solid particles. This method has a high clarified oil yield and good solid removal effect. However, there are problems with the filter material clogging easily and the waste residue from the oil slurry after adding the solid separation agent is difficult to dispose of as hazardous waste. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for reducing the solid content in catalytic oil slurry on the basis of the existing technology.

[0006] The present invention provides a method for reducing the solid content in catalytic cracking oil slurry, comprising:

[0007] (1) mixing an additive with a raw oil and heating it to obtain a raw oil liquid, wherein the additive is a petroleum wax having a carbon number between C20 and C43 and a normal alkane mass content of 35 to 60%;

[0008] (2) mixing a diluent with the raw oil liquid in step (1) to obtain a raw oil liquid containing the diluent, cooling the mixture to obtain a liquid-solid mixture, and performing liquid-solid separation to obtain a desolidified oil liquid and a wax paste; the diluent is a C3-C6 fatty ketone and / or a C6-C8 aromatic hydrocarbon;

[0009] (3) After the diluent is removed from the desolidified oil liquid, a catalytic cracking oil slurry with solids removed is obtained; after the diluent is removed from the wax paste, an additive containing solids is obtained.

[0010] The beneficial effects of the method for reducing the solid content in catalytic cracking oil slurry provided by the present invention are:

[0011] 1) The method provided by the present invention adds C20-C43 petroleum wax with a high normal alkane content to melt into catalytic cracking oil slurry to obtain a raw oil liquid. During the cooling process, the petroleum wax and solid matter in the oil slurry form a eutectic wax crystal particle, and after removing the solid phase, a catalytic cracking oil slurry product with reduced solid content is obtained. 2) A mixed diluent of aromatic hydrocarbons and fatty ketones added during the crystallization process is conducive to the growth and formation of larger crystals in the raw oil liquid; at the same time, it reduces the solubility of the wax crystal particles, making the wax crystals easier to precipitate; it also helps to reduce the viscosity of the solution and increase the filtration separation speed; 3) The filter layer formed by the wax crystals during the filtration separation process serves to further intercept the catalyst powder; 4) After the auxiliary agent and diluent added in the desolidification step are recovered, the diluent is recycled, and the auxiliary agent can be partially recycled or used as a catalytic cracking feedstock, without generating oil-containing solid waste.

[0012] By adopting the method provided by the present invention, the solid matter removal rate of the catalytic cracking slurry is above 88%, and the solid content of the treated catalytic cracking slurry product can be as low as 0.01wt%.

[0013] Other features and advantages of the present invention are described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constitute a part of the specification and are used to explain the present invention together with the following detailed description, but do not constitute a limitation of the present invention.

[0015] Figure 1 The present invention provides a schematic flow diagram of a method for reducing the solids content in catalytic cracking oil slurry.

[0016] Reference numerals:

[0017] 1-Mixing unit 2-Crystallization unit 3-Liquid-solid separation unit 4, 5-Diluent removal unit

[0018] 6-Oil slurry raw material 7-Auxiliary agent 9, 13, 16-Diluent 11-Flushing agent

[0019] 14-desolidified oil slurry 17-solid-containing additive 8, 10, 12, 15-pipeline DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described in detail below.

[0021] The present invention provides a method for reducing the solid content in catalytic cracking oil slurry, comprising:

[0022] (1) mixing an additive with a raw oil and heating it to obtain a raw oil liquid, wherein the additive is a petroleum wax having a carbon number between C20 and C43 and a normal alkane mass content of 35 to 60%;

[0023] (2) mixing a diluent with the raw oil liquid obtained in step (1) to obtain a raw oil liquid containing the diluent, cooling the mixture to obtain a solid-liquid mixture, and performing solid-liquid separation to obtain a desolidified oil liquid and a wax paste, wherein the diluent is a C3-C6 fatty ketone and / or a C6-C8 aromatic hydrocarbon;

[0024] (3) After removing the diluent from the desolidified oil liquid, a catalytic cracking oil slurry with solids removed is obtained; after removing the diluent from the wax paste, an additive containing solids is obtained.

[0025] In the method provided by the present invention, the raw oil is catalytic cracking slurry, which refers to the bottom oil obtained after the heavy oil catalytic reaction product is cut and separated into light components such as gasoline and diesel and sent out of the device.

[0026] In the method provided by the present invention, the "mixing" described in step (1) can be performed by using a stirred tank, a pipeline pump, and a static mixer to stir and mix the raw oil and the additive, thereby obtaining a raw oil liquid containing the additive. Preferably, a static mixer is used to enhance the mixing effect. The static mixer described above belongs to the prior art, and the present invention can also use a conventional liquid mixer in the art.

[0027] The auxiliary agent in step (1) is a petroleum wax with a carbon number between C20 and C43, which is a paraffin product obtained from natural petroleum, wherein the normal alkane content is 35 to 60% by weight.

[0028] Preferably, the carbon number of the additive is C25-C40, the normal alkane content is 40-55% by weight, and the additive is solid at room temperature, with a melting point between 55-70°C, more preferably between 60-68°C.

[0029] In step (1), the additive and the raw oil are mixed uniformly at a mixing temperature to obtain a liquid raw oil liquid. Preferably, the additive is added to the raw oil and mixed uniformly. The mixing temperature of the additive and the raw oil is 65 to 90° C.; preferably, the mixing temperature of the additive and the raw oil is 70 to 85° C.

[0030] The amount of the auxiliary agent in step (1) is 0.5 to 30 weight % of the raw oil; preferably, the amount of the auxiliary agent is 3 to 25 weight % of the raw oil; more preferably, it is 5 to 20 weight % of the raw oil.

[0031] In the method provided by the present invention, in step (2), the diluent is a C3-C6 aliphatic ketone and / or a C6-C8 aromatic hydrocarbon, wherein the C3-C6 aliphatic ketone is selected from one or more of acetone, butanone, pentanone and octanone, preferably butanone; and the C6-C8 aromatic hydrocarbon is selected from one or more of benzene, toluene and xylene, preferably toluene.

[0032] Preferably, the diluent is a mixture of aliphatic ketone and aromatic hydrocarbon, wherein the volume ratio of aliphatic ketone to aromatic hydrocarbon is 40:60 to 70:30, more preferably 45:55 to 65:35, and even more preferably 50:50 to 60:40. In a preferred technical solution, the diluent is a mixture of butanone and toluene.

[0033] The diluent is mixed evenly with the raw oil liquid obtained in step (1) to obtain a raw oil liquid containing the diluent, and the mixture is cooled to a temperature lower than the melting point of the auxiliary agent so that the auxiliary agent crystallizes to form a liquid-solid mixture. The solid-liquid separation is carried out at the liquid-solid separation temperature to obtain a desolidified oil liquid and a solid-containing auxiliary agent. After removing the diluent, the catalytic oil slurry and the solid-containing auxiliary agent are obtained respectively. The solid-liquid separation can adopt conventional solid-liquid separation methods in the art, such as natural sedimentation and filtration separation, and preferably filtration separation. The liquid-solid separation method can adopt existing technologies and will not be described in detail here.

[0034] In step (2), the mass ratio of the diluent to the raw oil is 0.5-4, preferably 1-3.5, more preferably 1.5-3.

[0035] In the method provided by the present invention, the diluent can be added to the raw oil obtained in step (1) at one time for mixing, or can be added in multiple times, preferably in two times. Preferably, the amount of diluent added in the first time is 14-50% of the total diluent.

[0036] In the method provided by the present invention, the temperature of the first addition of the diluent to the raw oil in step (2) is 50-80°C, preferably 55-75°C. After the first addition of the diluent and mixing, a raw oil containing the diluent is obtained. The raw oil containing the diluent is cooled to 15-35°C, preferably 20-30°C, and the diluent is added for the second time. The temperature is further lowered until the auxiliary agent crystallizes to form a liquid-solid mixture, and then liquid-solid separation is performed. The liquid-solid separation temperature is -10-30°C, preferably -5-25°C, and more preferably 0-20°C.

[0037] Preferably, the raw oil liquid containing the diluent is slowly cooled to the liquid-solid separation temperature. Starting from the first addition of the diluent, the cooling rate of the raw oil liquid containing the diluent is 0.5-4°C / min, more preferably 1-3.5°C / min, and even more preferably 1.5-3°C / min. Too fast a cooling rate will lead to poor crystallization effect, difficult liquid-solid separation, and difficulty in achieving solid-liquid separation.

[0038] In the method provided by the present invention, step (3) removes the diluent from the desolidified oil liquid to obtain a catalytic cracking slurry depleted of solids; and removes the diluent from the wax paste to obtain a solid-containing additive. The obtained catalytic slurry depleted of solids can be used as a raw material for the production of other products, and the obtained solid-containing additive is preferably returned to the catalytic cracking unit as a raw material.

[0039] The method for removing the diluent from the desolidified oil and wax paste is well known in the art, for example, the streams are respectively sent to a distillation tower for fractionation to remove the diluent, and the recovered diluent is recycled.

[0040] The present invention provides a method for reducing the solids content in a catalytic cracking oil slurry. The method comprises adding a C25-C40 petroleum wax additive having a normal paraffin content of 40-55% by mass to a feedstock oil, dissolving the additive into the feedstock oil under mixing conditions, and uniformly mixing the additive-containing oil with a diluent under dilution conditions to form a solid solution comprising the additive, feedstock oil, and diluent. The solid solution is cooled to a liquid-solid separation temperature under cooling conditions, and after separation and removal of the diluent, a catalytic cracking oil slurry with reduced solids content and the solids-containing additive are obtained. The diluent is preferably a mixture of C3-C6 fatty ketones and C6-C8 aromatic hydrocarbons, which facilitates crystallization of the C25-C40 petroleum wax additive in the solid solution during the cooling process, forming a wax eutectic of catalyst powder and petroleum wax, thereby reducing the solids content in the catalytic cracking oil slurry. A small amount of catalyst solid particles that do not form a wax eutectic with the petroleum wax additive are retained under filtration and separation conditions, further reducing the solids content of the desolidified catalytic cracking oil slurry. The catalytic slurry after solids removal is an excellent raw material for the production of carbon black, petroleum coke and aromatics extraction to produce rubber additives or asphalt softeners and other products.

[0041] The specific embodiments of the present invention are described clearly and completely below with reference to the accompanying drawings.

[0042] Attachment Figure 1 The schematic diagram of the process for reducing the solid content in catalytic cracking oil slurry provided by the present invention is shown in the attached figure. Figure 1As shown, the oil slurry raw material 6 and the additive 7 are introduced into the mixing unit 1 for mixing. The mixed product raw oil liquid is introduced into the crystallization unit 2 through pipeline 8 to mix with the diluent 9. At the same time, the temperature of the mixture is slowly reduced to allow the additive to crystallize. The liquid-solid mixture after crystallization is introduced into the solid-liquid separation unit 3 through pipeline 10 for solid-liquid separation. The solid-liquid separation unit preferably uses a filtering device to obtain desolidified oil liquid and solid-containing additive paste respectively. The flushing agent 11 enters the solid-liquid separation unit 3 to rinse the filter cake. The desolidified oil liquid enters the desolventizing unit 4 through pipeline 12 to remove the diluent. The desolventizing unit preferably uses a fractionating tower. The desolidified oil slurry is obtained through pipeline 14, and the diluent is obtained through pipeline 13. The solid-containing additive paste enters the desolventizing unit 5 through pipeline 15. The fractionated diluent is drawn out through pipeline 16 to obtain the solid-containing additive through pipeline 17.

[0043] The above describes the specific embodiments of the present invention in detail, wherein the specific technical features described therein can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0044] The technical effects of the present invention will be described below by way of examples, which however do not constitute a limitation of the present invention.

[0045] In the Examples and Comparative Examples:

[0046] Feedstock A is catalytic cracking slurry oil obtained from the catalytic cracking unit of Sinopec Shijiazhuang Branch; feedstock B is catalytic cracking slurry oil obtained from the catalytic cracking unit of Sinopec Jiujiang Refining and Chemical Company; their properties are shown in Table 1.

[0047] Additive A is No. 68 petroleum wax obtained from Sinopec Jinan Branch; Additive B is No. 62 petroleum wax obtained from Sinopec Yanshan Branch. The properties are shown in Table 2.

[0048] Example 1

[0049] (1) Add additive A to raw oil A and mix them at 85°C to obtain a raw oil liquid. The amount of additive A added is 10% by weight of the raw oil.

[0050] (2) A mixture of butanone and toluene is used as a diluent and a flushing agent, wherein the volume fraction of butanone is 55% and the volume fraction of toluene is 45%. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The temperature when the diluent is added for the first time is 55°C, and the temperature when the diluent is added for the second time is 25°C. The cooling rate is 1.5°C / min. When the raw oil liquid containing the diluent is cooled to 10°C, a liquid-solid mixture is formed. The mixture is filtered and separated. The filter cake is rinsed with a flushing agent at 10°C to obtain a desolidified oil liquid and a solid wax paste. The mass ratio of the diluent to the raw oil is 1.5:1. The dilution ratio (mass ratio of the diluent to the raw oil liquid) of the first addition of the diluent is 0.5; the dilution ratio of the second addition of the diluent is 1; and the mass ratio of the flushing agent to the raw oil is 0.5.

[0051] (3) The desolidified oil liquid and the solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified catalytic cracking oil slurry and the solid removal product were obtained respectively. After analysis, the density of the desolidified oil slurry at 20°C was 1129.3 kg / m 3 , the kinematic viscosity at 100℃ is 29.52mm 2 / s, and the carbon residue was 11.75%. Other results are shown in Table 3.

[0052] The calculation formulas for the parameters involved in Table 3 are:

[0053] Desolidified oil slurry yield = desolidified oil slurry mass ÷ raw oil mass × 100%;

[0054] Solid removal rate = (mass of solids in crude oil - mass of solids in desolidified oil slurry) ÷ mass of solids in crude oil × 100%.

[0055] The calculation formulas for the desolidified oil slurry yield, solid-containing additive yield, and solid removal rate in the following examples are the same.

[0056] Example 2

[0057] (1) Add additive A to raw oil A and mix them at 80°C to obtain a raw oil liquid. The amount of additive A added is 25% by weight of the raw oil.

[0058] (2) A mixture of butanone and toluene is used as a diluent and a flushing agent, wherein the volume fraction of butanone is 65% and that of toluene is 35%. The diluent is added to the raw oil liquid twice and mixed to obtain a raw oil liquid containing the diluent. The liquid-solid mixture is filtered and separated when the temperature is lowered to 25°C. The filter cake is rinsed with a flushing agent to obtain a desolidified oil liquid and a solid wax paste. The temperature of the first addition of the diluent is 70°C, and the dilution ratio (mass ratio of the diluent to the raw oil liquid) is 0.5; the temperature of the second addition of the diluent is 30°C, and the dilution ratio is 3; the cooling rate is 3.5°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0059] (3) The desolidified oil and solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified catalytic cracking oil slurry and solid removal product were obtained respectively. After analysis, the density of the desolidified catalytic cracking oil slurry at 20°C was 1130.8 kg / m 3 , the kinematic viscosity at 100℃ is 30.18mm 2 / s, and the carbon residue was 11.82%. Other results are shown in Table 3.

[0060] Example 3

[0061] (1) Add additive B to raw oil A and mix at 75°C to obtain a raw oil liquid. The amount of additive A added is 5% by weight of the raw oil.

[0062] (2) A mixture of butanone and toluene is used as a diluent and a flushing agent, wherein the volume fraction of butanone is 60% and the volume fraction of toluene is 40%. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture is cooled to 0°C and filtered to separate the formed liquid-solid mixture. The filter cake is rinsed with the flushing agent to obtain a desolidified oil liquid and a solid-containing wax paste. The temperature of the first addition of the diluent is 75°C, and the dilution ratio (mass ratio of the diluent to the raw oil liquid) is 0.5; the temperature of the second addition of the diluent is 30°C, and the dilution ratio is 1.5; the cooling rate is 2°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0063] (3) The desolidified oil and the solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified catalytic cracking oil slurry and the solid removal product were obtained respectively. After analysis, the density of the desolidified catalytic cracking oil slurry at 20°C was 1142.8 kg / m 3 , the kinematic viscosity at 100℃ is 34.23mm 2 / s, and the carbon residue was 11.72%. Other results are shown in Table 3.

[0064] Comparative Example 1

[0065] (1) Using raw oil B without adding additives;

[0066] (2) A mixture of butanone and toluene was used as a diluent and a flushing agent, wherein the volume fraction of butanone was 50% and the volume fraction of toluene was 50%. The diluent was added to the crude oil B twice to obtain a homogeneous mixture. The liquid-solid mixture was filtered and separated after cooling to 20°C. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a filter cake. The temperature of the first diluent addition was 70°C, and the dilution ratio was 0.5. The temperature of the second diluent addition was 20°C, and the dilution ratio was 2.5. The cooling rate was 3°C / min. The mass ratio of the flushing agent to the crude oil B was 0.5.

[0067] (3) The desolidified oil liquid and the solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified oil slurry and the solid removal product were obtained respectively. After analysis, the density of the desolidified oil slurry at 20°C was 1109.7 kg / m 3 , the kinematic viscosity at 100℃ is 25.72mm 2 / s, carbon residue value 10.25%, other results are shown in Table 3.

[0068] Example 4

[0069] (1) The additive A and the raw oil B were mixed at 70°C to obtain a raw oil liquid. The amount of additive A added was 15% by weight of the raw oil.

[0070] (2) A mixture of butanone and toluene is used as a diluent and a flushing agent, wherein the volume fraction of butanone is 50% and the volume fraction of toluene is 50%. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture is filtered and separated when the temperature is cooled to 20°C. The filter cake is rinsed with the flushing agent to obtain a desolidified oil liquid and a solid-containing wax paste. The temperature of the first addition of the diluent is 70°C, and the dilution ratio (mass ratio of the diluent to the raw oil) is 0.5; the temperature of the second addition of the diluent is 20°C, and the dilution ratio is 2.5; the cooling rate is 3°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0071] (3) The desolidified oil liquid and the solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified oil slurry and the solid removal product were obtained respectively. After analysis, the density of the desolidified oil slurry at 20°C was 1095.6 kg / m 3 , the kinematic viscosity at 100℃ is 20.58mm 2 / s, and the carbon residue value was 9.46%. Other results are shown in Table 3.

[0072] Example 5

[0073] (1) The additive B and the raw oil B are mixed uniformly at 80°C to obtain a raw oil liquid. The amount of additive B added is 3% by weight of the raw oil.

[0074] (2) A mixture of butanone and toluene is used as a diluent and a flushing agent, wherein the volume fraction of butanone is 55% and the volume fraction of toluene is 45%. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing a diluent. The liquid-solid mixture is filtered and separated at -5°C. The filter cake is rinsed with a flushing agent to obtain a desolidified oil liquid and a solid-containing wax paste. The temperature of the first addition of the diluent is 55°C, and the dilution ratio (mass ratio of the diluent to the raw oil) is 0.5; the temperature of the second addition of the diluent is 15°C, and the dilution ratio is 0.5; the cooling rate is 1°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0075] (3) The desolidified oil liquid and the solid wax paste were fractionated at 120°C to remove the diluent therein, and the desolidified oil slurry and the solid removal product were obtained respectively. After analysis, the kinematic viscosity of the desolidified oil slurry at 100°C was 21.06 mm 2 / s, and the carbon residue was 9.85%. Other results are shown in Table 3.

[0076] Table 1

[0077] project Crude Oil A Crude oil B Analytical methods <![CDATA[Density (20 °C) / (kg / m 3 )]]> 1145.5 1105.6 GB / T 13377 <![CDATA[Kinematic viscosity (100 °C) / (mm 2 / s)]]> 30.69 16.36 GB / T 265 Residual carbon value / % 12.15 9.5 GB / T 17144 w(solid matter) / % 0.54 0.26 Q / SH 0741 Sulfur mass fraction / % 0.999 0.828 GB / T 17040 Nitrogen mass fraction / % 0.11 0.25 SH / T 0704

[0078] Table 2

[0079] project Additive A Additive B Analytical methods Carbon number of normal alkanes C31~C40 C25~C37 SH / T 0889 w(normal alkanes) / % 39.4 54.8 SH / T 0889 Melting point / ℃ 68.5 60.4 GB / T 2539 <![CDATA[Kinematic viscosity at 100 °C / (mm 2 / s)]]> 6.427 4.640 GB / T 265

[0080] Table 3

[0081]

[0082] The results of reducing the solids content in catalytic cracking slurry in Comparative Example 1 and Example 4 demonstrate that the addition of a solids removal aid can effectively remove solids from catalytic cracking slurry by selecting an appropriate solids removal aid and diluent, and controlling the mixing temperature of the aid and catalytic cracking slurry, the dewaxing dilution conditions, and the dewaxing temperature. Compared to the solids removal results from catalytic cracking slurry without the addition of a solids removal aid, the slurry with the addition of a solids removal aid exhibits a lower solids content.

[0083] The results of Examples 1-5 demonstrate that the method provided by the present invention achieves a solids removal rate of 88.7-98.2% for the slurry oil, far exceeding the solids removal rate of the comparative example, with minimal changes in other properties. Compared to the feedstock oil, the method provided by the present invention achieves a high solids removal rate for the catalytic slurry oil, enabling it to be used as a high-quality, high-aromatics feedstock, increasing its value. The solids removal aid can be partially recycled or returned to the catalytic cracking unit, eliminating the generation of oil-containing solid waste and contributing to environmental protection, representing a green technology.

Claims

1. A method for reducing the solid content in catalytic cracking slurry, characterized in that: include: (1) mixing an additive with catalytic cracking slurry feedstock oil and heating the mixture to obtain a feedstock oil liquid, wherein the additive is petroleum wax having a carbon number between C20 and C43 and a normal alkane mass content of 35 to 60%; (2) mixing a diluent with the raw oil liquid in step (1) to obtain a raw oil liquid containing the diluent, cooling the mixture to obtain a solid-liquid mixture, and performing solid-liquid separation to obtain a desolidified oil liquid and a wax paste, wherein the diluent is a C3-C6 fatty ketone and a C6-C8 aromatic hydrocarbon, and the volume ratio of the fatty ketone to the aromatic hydrocarbon is 40:60-70:30; (3) After removing the diluent from the desolidified oil liquid, a catalytic cracking oil slurry with solids removed is obtained. After removing the diluent from the wax paste, an auxiliary agent containing solids is obtained. The auxiliary agent containing solids is returned to the catalytic cracking unit as a raw material.

2. The method for reducing the solid content in catalytic cracking slurry according to claim 1, characterized in that: The carbon number of the auxiliary agent is C25-C40, and the mass content of normal alkanes is 40-55%.

3. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: In step (1), the mixing temperature of the auxiliary agent and the raw oil is 65-90°C.

4. The method for reducing the solid content in catalytic cracking slurry according to claim 3, characterized in that: The mixing temperature of the auxiliary agent and the raw oil in step (1) is 70~85℃.

5. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: The amount of the auxiliary agent in step (1) is 3 to 25 weight % of the raw oil.

6. The method for reducing the solid content in catalytic cracking slurry according to claim 5, characterized in that: The amount of the auxiliary agent in step (1) is 5 to 20% by weight of the raw oil.

7. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: In the diluent, the volume ratio of the aliphatic ketone to the aromatic hydrocarbon is 45:55-65:

35.

8. The method for reducing the solid content in catalytic cracking slurry according to claim 7, characterized in that: In the diluent, the volume ratio of the aliphatic ketone to the aromatic hydrocarbon is 50:50-60:

40.

9. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: The aliphatic ketone in the diluent is acetone and / or butanone, and the aromatic hydrocarbon is benzene and / or toluene.

10. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: The mass ratio of the diluent to the raw oil is 0.5-4.

11. The method for reducing the solid content in catalytic cracking slurry according to claim 10, characterized in that: The mass ratio of diluent to raw oil is 1~3.

5.

12. The method for reducing the solid content in catalytic cracking slurry according to claim 11, characterized in that: The mass ratio of the diluent to the raw oil is 1.5-3.

13. The method for reducing the solid content in catalytic cracking slurry according to claim 1 or 2, characterized in that: The diluent is added into the raw oil liquid in two batches for mixing, and the amount of the diluent added in the first batch is 14-50% of the total diluent.

14. The method for reducing the solid content in catalytic cracking slurry according to claim 13, characterized in that: In step (2), the temperature of the first addition of the diluent to the raw oil liquid is 50~80°C; the temperature of the second addition of the diluent is 15~35°C; and the solid-liquid separation temperature of the raw oil liquid containing the diluent after cooling is -10~30°C.

15. The method for reducing the solid content in catalytic cracking oil slurry according to claim 14, characterized in that: In step (2), the temperature of the first addition of the diluent to the raw oil liquid is 55~75°C, and the temperature of the second addition of the diluent is 20~30°C; the liquid-solid separation temperature of the raw oil liquid containing the diluent after cooling is -5~25°C.

16. The method for reducing the solid content in catalytic cracking slurry according to claim 15, characterized in that: The liquid-solid separation temperature of the raw oil containing diluent after cooling is 0~20℃.

17. The method for reducing the solid content in catalytic cracking slurry according to claim 9, characterized in that: The cooling rate of the mixture of the raw oil and the diluent is 0.5~4℃ / min.

18. The method for reducing the solid content in catalytic cracking oil slurry according to claim 17, characterized in that: The cooling rate of the mixture of the raw oil and the diluent is 1~3.5℃ / min.

19. The method for reducing the solid content in catalytic cracking slurry according to claim 18, characterized in that: The cooling rate of the mixture of the raw oil and the diluent is 1.5~3℃ / min.

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