A method for reducing solid content of catalytic cracking slurry

Abstract

A method for reducing the solid content of catalytic cracking oil slurry, comprising: (1) mixing an auxiliary agent with a raw oil and heating it to obtain a raw oil liquid, wherein the auxiliary agent is a petroleum wax having a carbon number of C30 to C75 and a paraffin and a small-ring cycloparaffin content of 50 to 60% by weight; (2) mixing a C6-C8 aromatic hydrocarbon diluent with the raw oil liquid to obtain a raw oil liquid containing the diluent, cooling the mixture until the auxiliary agent crystallizes, and performing liquid-solid separation to obtain a desolidified oil liquid and a wax paste; (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry with reduced solid content, and removing the diluent from the wax paste to obtain an auxiliary agent containing solids. The method provided by the present invention has simple steps, is green and environmentally friendly, and can significantly reduce the solid content of the catalytic cracking oil slurry, with a removal rate of greater than 85%.

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 content of a heavy oil catalytic reaction product by adopting a liquid-solid 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. It features 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. It has high application value and promising prospects. The main factor limiting the high-value utilization of slurry oil is the catalyst fines in the catalytic cracking slurry oil. Its content is determined by solids content measurement. The solids content of catalytic cracking slurry oil generally 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-speed 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, thereby achieving the purpose of accelerating the sedimentation rate of the catalyst powder. The filtration separation method uses a filter medium to intercept and remove the catalyst powder from the catalytic oil slurry. The key to the technology is to select a suitable filter medium, and require the filter medium to have good regeneration performance and be able to operate stably for a long time. Centrifugal separation is a method of separating catalyst powder from 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] ZL99109217.1 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 steps such as filtration, backwashing, and dilution. 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, but there is a problem with the increase in the amount of solid residue removed from the oil slurry after adding the solid separation agent. To address the problems of easy clogging of the filter material and the increase in the amount of solid residue removed from the oil slurry after adding the solid separation agent, the present invention proposes an improved method for removing solids from the catalytic cracking oil slurry in response to the shortcomings of existing filtration methods for removing catalyst from catalytic cracking oil slurry. 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 of catalytic oil slurry on the basis of the existing technology.

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

[0007] (1) mixing an auxiliary agent with a raw oil, heating and melting the mixture to form a raw oil liquid, wherein the auxiliary agent is a petroleum wax having a carbon number of C30 to C75 and a paraffin and a small-ring cycloparaffin content of 55 to 60% by weight;

[0008] (2) Mixing a diluent with the raw oil liquid to obtain a raw oil liquid containing the diluent, cooling the raw oil liquid until the additive crystallizes, and performing liquid-solid separation to obtain a desolidified oil liquid and a solid additive paste; the diluent is a C6-C8 aromatic hydrocarbon.

[0009] (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry with solids removed, and removing the diluent from the solid-containing additive paste to obtain a solid-containing additive.

[0010] Among them, the few-ring cycloalkanes refer to monocyclic cycloalkanes and bicyclic cycloalkanes.

[0011] Compared with the prior art, the method for reducing the solid content in catalytic oil slurry provided by the present invention has the following beneficial effects:

[0012] The method provided by the present invention adds a petroleum wax having a carbon number of C30 to C75 and a paraffin and oligocyclic cycloalkanes content of 55 to 60% by weight to a catalytic cracking oil slurry. During the cooling process, the petroleum wax easily forms compact crystalline particles with the catalyst powder in the oil slurry, making the catalyst particles easy to remove and achieving a high desolidified oil yield. In addition, the C6-C8 aromatic hydrocarbon diluent added to the oil liquid helps to evenly disperse the petroleum wax additive in the solution; helps the petroleum wax crystals gradually precipitate to form uniform crystals in the liquid phase during the cooling process; and helps to reduce the viscosity of the solution and increase the solid-liquid separation rate. After the additives and diluents added in the desolidification step are recovered, the diluent can be recycled, and the desolidification agent can be partially recycled or used as a catalytic cracking feedstock, without generating oil-containing solid waste.

[0013] By adopting the method provided by the present invention, the solid matter removal rate of the catalytic cracking slurry is greater than 85%, and the solid content of the catalytic cracking slurry after solid removal can reach a minimum of 0.01wt%.

[0014] Other features and advantages of the present invention are described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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.

[0016] Figure 1 A schematic flow diagram of a method for reducing the solid content of catalytic cracking oil slurry.

[0017] Description of reference numerals:

[0018] 1-Mixing unit 2-Crystallization unit 3-Liquid-solid separation unit 4, 5-Diluent removal unit

[0019] 6-Oil slurry raw material 7-Auxiliary agent 9, 13, 16-Diluent 11-Flushing agent

[0020] 14-desolidified oil slurry 17-solid-containing additive 8, 10, 12, 15-pipeline DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described in detail below.

[0022] The present invention provides a method for reducing the solid content of catalytic cracking oil slurry, comprising:

[0023] (1) mixing an auxiliary agent with a raw oil, heating and melting the mixture to form a raw oil liquid, wherein the auxiliary agent is a petroleum wax having a carbon number of C30 to C75 and a paraffin and a small-ring cycloparaffin content of 55 to 60% by weight;

[0024] (2) Mixing a diluent with the raw oil liquid to obtain a raw oil liquid containing the diluent, cooling the raw oil liquid until the additive crystallizes, and performing liquid-solid separation to obtain a desolidified oil liquid and a solid additive paste; the diluent is a C6-C8 aromatic hydrocarbon.

[0025] (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry with solids removed, and removing the diluent from the solid-containing additive paste to obtain a solid-containing additive.

[0026] In the method provided by the present invention, the raw oil is the bottom oil obtained by cutting and separating the light components such as diesel from the heavy oil catalytic reaction product and the part sent out of the device.

[0027] In the method provided herein, the raw oil and the additive can be mixed using a stirred tank, a pipeline pump, and a static mixer to obtain a raw oil liquid containing the additive. Preferably, a static mixer is used to enhance the mixing effect. The static mixer is known in the art, and conventional liquid mixers in the art can be used in the present invention.

[0028] In the method provided herein, the petroleum wax is paraffin wax obtained from natural petroleum. The petroleum wax is microcrystalline wax with a carbon number of C30 to C75, and the main components of the microcrystalline wax are paraffins and cycloalkanes, with a small amount of aromatic hydrocarbons. The paraffin and low-ring cycloalkanes content in the additive is 55 to 60% by weight.

[0029] Preferably, the additive has a carbon number of C45-C75 and a paraffin and oligocyclic cycloparaffin content of 35-45% by weight. The petroleum wax is solid at room temperature and has a melting point of 75-85°C, more preferably 77-80°C.

[0030] Among them, the few-ring cycloalkanes refer to monocyclic cycloalkanes and bicyclic cycloalkanes.

[0031] In the method provided by the present invention, in step (1), the additive and the raw oil are uniformly mixed at a mixing temperature to obtain a liquid raw oil liquid. Optionally, the additive is added to the raw oil and mixed uniformly. The mixing temperature of the additive and the raw oil is 75 to 120° C., preferably 80 to 115° C. The mixing temperature is the temperature at which the additive and the raw oil are uniformly mixed to obtain the raw oil liquid.

[0032] In step (1), the amount of the additive is 0.5 to 30% by weight of the raw oil; preferably 3 to 25% by weight of the raw oil, and more preferably 5 to 20% of the raw oil. Increasing the amount of additive improves the desolidification effect, but excessive addition of additive reduces the desolidification slurry yield and increases costs.

[0033] In the method provided by the present invention, in step (2), the diluent is selected from C6-C8 aromatic hydrocarbons, and is selected from one or more of benzene, toluene, and xylene. Preferably, the diluent is benzene and / or toluene; more preferably, toluene.

[0034] In step (2), the diluent is mixed evenly with the raw oil liquid obtained in step (1), and the mass ratio of the diluent to the raw oil is 0.5 to 3.5:1, preferably 1 to 3:1, and more preferably 1.5 to 2.5:1.

[0035] A diluent is added to the mixture and mixed to obtain a raw oil liquid containing the diluent. The mixture is then cooled to a temperature below the melting point of the additive, so that the additive and the catalyst powder in the raw oil liquid form compact crystalline particles to obtain a liquid-solid mixture. The solid-liquid separation is carried out at a separation temperature to obtain a desolidified oil liquid and a solid-containing additive. The solid-liquid separation can be carried out using conventional solid-liquid separation methods in the art, such as natural sedimentation and filtration separation, preferably filtration separation. The liquid-solid separation method can adopt existing technologies and will not be described in detail here.

[0036] In the presence of an aromatic hydrocarbon diluent, the high-carbon alkane additive dissolves and disperses in the feedstock oil, capturing catalyst particles and forming compact crystalline particles. Filtration and separation trap the catalyst powder in the feedstock oil, thereby removing the solids from the catalytic oil slurry. The solids-free catalytic oil slurry is an excellent raw material for the manufacture of carbon black, petroleum coke, and aromatics extraction to produce rubber additives and asphalt softeners.

[0037] In 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, with the amount of the first diluent added being 17-50% of the total diluent.

[0038] Preferably, the mixing temperature of the first addition of the diluent to the raw oil in step (2) is 70-100° C., preferably 75-90° C. After mixing, a raw oil containing the diluent is obtained, and the raw oil containing the diluent is cooled to 25-45° C., preferably 30-40° C., and the diluent is added for the second time. The temperature is further lowered to the separation temperature before solid-liquid separation is performed. The separation temperature is -15-25° C., preferably -10-20° C., and more preferably -5-15° C.

[0039] Preferably, the feedstock oil containing the diluent is slowly cooled to the separation temperature at a cooling rate of 0.5-4°C / min, more preferably 1-3.5°C / min, and even more preferably 1.5-3°C / min. A cooling rate that is too fast will result in poor crystallization, difficult filtration, and inability to achieve solid-liquid separation.

[0040] In the method provided by the present invention, step (3) removes the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry with solids removed; and removes the diluent from the wax paste to obtain a solid-containing additive. The obtained catalytic cracking oil slurry with solids removed can be used as a raw material for the production of other products, and the obtained solid-containing additive is preferably returned to the post-processing device as a raw material.

[0041] Preferably, the obtained solid-containing additive is returned to the catalytic cracking unit as a raw material.

[0042] 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.

[0043] The present invention provides a method for reducing the solid content in catalytic cracking oil slurry. The method comprises adding a petroleum wax having a carbon number of C30 to C75 and a paraffin and low-ring aromatic hydrocarbon content of 55 to 60% by weight to a raw oil, dissolving an additive in the raw oil under mixing conditions, uniformly mixing the oil containing the additive with a diluent under dilution conditions to form a solid solution of the additive, raw oil, and diluent. The solid solution is cooled to a filtration separation temperature under cooling conditions, and after separation and removal of the diluent, a catalytic cracking oil slurry with reduced solid content and a solid-containing additive are obtained. The C6-C8 aromatic hydrocarbon diluent facilitates crystallization of the additive dissolved in the solution during the cooling process, forming compact wax crystals of the catalyst and additive, thereby achieving the purpose of reducing the solid content in the catalytic oil slurry. A small amount of catalyst that does not form compact wax crystals with the additive is retained under filtration separation conditions, further reducing the solid content of the desolidified oil slurry. The catalytic oil slurry from which the solids have been removed is an excellent raw material for the production of carbon black, petroleum coke, and aromatics extraction to produce rubber additives or asphalt softeners.

[0044] The following is a clear and complete description of the specific implementation of the method for reducing the solid content of catalytic cracking oil slurry provided by the present invention in conjunction with the accompanying drawings.

[0045] Attachment Figure 1 Schematic diagram of the process for reducing the solid content of catalytic cracking oil slurry provided by the present invention. Figure 1As shown, the oil slurry raw material 6 and the auxiliary agent 7 are introduced into the mixing unit 1 for mixing. The mixed product is introduced into the crystallization unit 2 through the raw oil liquid pipeline 8 to mix with the diluent 9. At the same time, the temperature of the mixture is slowly reduced to allow the auxiliary agent 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 wax 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 auxiliary agent paste enters the desolventizing unit 5 through pipeline 15. The fractionated diluent is drawn out through pipeline 16 to obtain the solid-containing auxiliary agent through pipeline 17.

[0046] 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.

[0047] 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.

[0048] In the Examples and Comparative Examples:

[0049] Feedstock A is the catalytic cracking slurry oil obtained from the catalytic cracking unit of Sinopec Jiujiang Refining and Chemical Company. Its properties are shown in Table 1.

[0050] Feedstock B is the catalytic cracking slurry oil obtained from the catalytic cracking unit of Fujian Refining and Chemical Company. The properties are shown in Table 1.

[0051] Feedstock C is the catalytic cracking slurry oil obtained from the catalytic cracking unit of Sinopec Shijiazhuang Branch. Its properties are shown in Table 1.

[0052] Additive A is microcrystalline wax obtained from Northern Asphalt Fuel Co., Ltd., and its properties are shown in Table 2.

[0053] Additive B is microcrystalline wax obtained from Jinan Refining and Chemical Company. Its properties are shown in Table 2.

[0054] Example 1

[0055] (1) Adding additive A to raw oil A, mixing at 80°C to obtain a raw oil liquid containing additive, wherein the amount of additive A added is 5% by weight of the raw oil.

[0056] (2) Toluene is used as a diluent and a flushing agent. 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 a flushing agent to obtain a desolidified oil liquid and a solid-containing wax paste. The temperature of the first diluent addition is 75°C, and the dilution ratio (mass ratio of diluent to raw oil) is 0.5; the temperature of the second diluent addition is 35°C, and the dilution ratio is 1.5; the cooling rate is 3°C / min, and the mass ratio of flushing agent to raw oil is 0.5.

[0057] (3) The desolidified oil liquid and the solid wax paste were fractionated at 115°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 1102.7 kg / m 3 , the kinematic viscosity at 100℃ is 22.05mm 2 / s, the carbon residue value is 9.72%. Other results are shown in Table 3. The calculation formula for the parameters in Table 3 is:

[0058] Desolidified oil slurry yield = desolidified oil slurry mass ÷ raw oil mass × 100%;

[0059] Solid removal rate = (mass of solids in crude oil - mass of solids in desolidified oil slurry × desolidified oil slurry yield ÷ 100) ÷ mass of solids in crude oil × 100%.

[0060] Comparative Example 1

[0061] (1) Using raw oil A without adding additives;

[0062] (2) Toluene was added to the crude oil A twice as a diluent and a flushing agent to obtain a homogeneous mixture. The liquid-solid mixture was cooled to 0°C and filtered to separate the resulting mixture. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a filter cake. The first addition of the diluent was at a temperature of 75°C and a dilution ratio of 0.5. The second addition of the diluent was at a temperature of 35°C and a dilution ratio of 1.5. The cooling rate was 3°C / min, and the mass ratio of the flushing agent to the crude oil was 0.5.

[0063] (3) The desolidified oil liquid and the solid wax paste were fractionated at 115°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 1111.1 kg / m 3 , the kinematic viscosity at 100℃ is 22.88mm 2 / s, carbon residue value 10.19%, other results are shown in Table 3.

[0064] Example 2

[0065] (1) The additive B and the raw oil A are mixed at 115°C to obtain a raw oil liquid containing the additive. The amount of additive B added is 20% by weight of the raw oil.

[0066] (2) Toluene is used as a diluent and a flushing agent. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture formed 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 90°C, and the dilution ratio (mass ratio of diluent to raw oil) is 0.5; the temperature of the second addition of the diluent is 30°C, and the dilution ratio is 0.5; the cooling rate is 2°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0067] (3) The desolidified oil liquid and the solid wax paste were fractionated at 115°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 1098.0 kg / m 3 , the kinematic viscosity at 100℃ is 23.16mm 2 / s, the residual carbon value was 10.57%, and other results are shown in Table 3.

[0068] Example 3

[0069] (1) The additive A and the raw oil B are mixed at 95°C to obtain a raw oil liquid containing the additive. The amount of additive A added is 10% by weight of the raw oil.

[0070] (2) Toluene is used as a diluent and a flushing agent. 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 at a temperature of 10°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 80°C, and the dilution ratio (mass ratio of diluent to raw oil) is 0.5; the temperature of the second addition of the diluent is 40°C, and the dilution ratio is 1; the cooling rate is 1.5°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 115°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 1123.0 kg / m 3 , the kinematic viscosity at 100℃ is 52.44mm 2 / s, the residual carbon value was 13.76%, and other results are shown in Table 3.

[0072] Example 4

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

[0074] (2) Toluene is used as a diluent and a flushing agent. 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 at 25°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 75°C, and the dilution ratio (mass ratio of diluent to raw oil) is 0.5; the temperature of the second addition of the diluent is 45°C, and the dilution ratio is 2.5; 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 115°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 1133.8 kg / m 3 , the kinematic viscosity at 100℃ is 32.17mm 2 / s, the residual carbon value was 11.76%, and other results are shown in Table 3.

[0076] Example 5

[0077] (1) The additive B and the raw oil C are mixed at 115°C to obtain a raw oil liquid containing the additive. The amount of additive A added is 25% by weight of the raw oil.

[0078] (2) Toluene is used as a diluent and a flushing agent. The diluent is mixed with the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture formed is filtered and separated at -10°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 90°C, and the dilution ratio (mass ratio of diluent to raw oil) is 0.5; the temperature of the second addition of the diluent is 35°C, and the dilution ratio is 2; the cooling rate is 3.5°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0079] (3) The desolidified oil liquid and the solid wax paste were fractionated at 115°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 1136.9 kg / m 3 , the kinematic viscosity at 100℃ is 33.24mm 2 / s, the residual carbon value was 11.56%, and other results are shown in Table 3.

[0080] Table 1

[0081]

[0082] Table 2

[0083] project Additive A Additive B Analytical methods Alkane carbon number C45~C75 C45~C75 ASTM D7169 Alkanes and less-ring aromatic hydrocarbons / % 39.11 35.43 Drop melting point / ℃ 77.0 79.9 GB / T 8026 <![CDATA[100℃ kinematic viscosity / (mm 2 / s)]]> 12.93 19.16 GB / T 265

[0084] Table 3

[0085] Desolidified oil slurry yield / % Desolidified oil slurry solid content / wt% Solid removal rate / % Comparative Example 1 99.1 0.19 27.6 Example 1 98.1 0.01 96.2 Example 2 93.7 0.01 96.4 Example 3 95.5 0.01 93.6 Example 4 98.8 0.08 85.4 Example 5 88.3 0.01 98.4

[0086] The results of Comparative Example 1 and Example 1 in Table 3 demonstrate that the method provided by the present invention, combined with simultaneous control of the mixing temperature of the additive and catalytic slurry, the dewaxing dilution conditions, and the dewaxing temperature, effectively removes solids from the catalytic slurry. Compared to the solids removal results from catalytic slurry without the additive, the resulting desolidified slurry has a lower solids content.

[0087] The results of Examples 1-5 demonstrate that the present method achieves a slurry oil solids removal rate of 85.4-98.4%, significantly exceeding the solids removal rate of the comparative example, with minimal changes in other properties. The present method achieves a high solids removal rate for the catalytic slurry oil, enabling it to be used as a high-quality, high-aromatic hydrocarbon 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 of catalytic cracking slurry, characterized in that: include: (1) mixing an additive with a catalytic cracking oil slurry raw material, heating and melting the mixture to form a raw oil liquid, wherein the additive is a petroleum wax having a carbon number of C45 to C75 and a paraffin and a less-ring cycloalkane content of 35 to 45% by weight, wherein the less-ring cycloalkane refers to a monocyclic cycloalkane and a dicyclic cycloalkane; (2) mixing a diluent with the raw oil liquid to obtain a raw oil liquid containing the diluent, cooling the raw oil liquid until the additive crystallizes therein, and performing liquid-solid separation to obtain a desolidified oil liquid and a solid additive paste; the diluent is a C6-C8 aromatic hydrocarbon; (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry with solids removed, and removing the diluent from the solid-containing additive paste to obtain the additive containing solids; and returning the solid-containing additive to the catalytic cracking unit as a raw material.

2. The method for reducing the solid content of catalytic cracking slurry according to claim 1, characterized in that: In step (1), the mixing temperature of the auxiliary agent and the catalytic cracking oil slurry raw material is 75-120° C., and the mixing temperature is the temperature at which the auxiliary agent and the catalytic cracking oil slurry raw material are uniformly mixed to obtain the raw oil liquid.

3. The method for reducing the solid content of catalytic cracking oil slurry according to claim 2, characterized in that: In step (1), the mixing temperature of the additive and the catalytic cracking oil slurry raw material is 80-115°C.

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

5. The method for reducing the solid content of catalytic cracking slurry according to claim 4, characterized in that: The amount of the auxiliary agent is 5 to 20 weight % of the catalytic cracking slurry raw material.

6. The method for reducing the solid content of catalytic cracking oil slurry according to claim 1, 2 or 3, characterized in that: The diluent is benzene and / or toluene.

7. The method for reducing the solid content of catalytic cracking slurry according to claim 6, characterized in that: The diluent is toluene.

8. The method for reducing the solid content of catalytic cracking slurry according to claim 1, 2 or 3, characterized in that: The mass ratio of the diluent to the catalytic cracking oil slurry raw material is 1-3:

1.

9. The method for reducing the solid content of catalytic cracking oil slurry according to claim 8, characterized in that: The mass ratio of the diluent to the catalytic cracking oil slurry raw material is 1.5-2.5:

1.

10. The method for reducing the solid content of catalytic cracking slurry according to claim 1, 2 or 3, characterized in that: In step (2), the diluent is added to the raw oil liquid in two batches for mixing, and the amount of the diluent added for the first time is 17-50% of the total diluent; the temperature of the raw oil liquid when the diluent is added for the first time is 70-100°C; the temperature of the second time when the diluent is added is 25-45°C; and the liquid-solid separation temperature is -15-25°C.

11. The method for reducing the solid content of catalytic cracking slurry according to claim 10, characterized in that: In step (2), the temperature of the first diluent added to the raw oil liquid is 75~90°C, and the temperature of the second diluent added is 30~40°C; the liquid-solid separation temperature is -10~20°C.

12. The method for reducing the solid content of catalytic cracking slurry according to claim 11, characterized in that: The liquid-solid separation temperature is -5~15℃.

13. The method for reducing the solid content of catalytic cracking slurry according to claim 1, 2 or 3, characterized in that: The cooling rate of the raw oil liquid containing the diluent to the liquid-solid separation temperature is 0.5-4°C / min.

14. The method for reducing the solid content of catalytic cracking slurry according to claim 13, characterized in that: The cooling rate of the raw oil liquid containing the diluent is 1.5-3°C / min.

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