Method and device for removing solid matter from catalytic cracking oil slurry

Abstract

A method and apparatus for removing solids from catalytic cracking oil slurry, the method comprising: (1) mixing an auxiliary agent with raw oil and heating it to obtain a raw oil liquid, wherein the auxiliary agent is petroleum wax and / or synthetic wax, having a carbon number between C16 and C35 and a normal paraffin mass content of 70 to 85%; (2) mixing a diluent with the raw oil liquid in step (1), cooling it to obtain a liquid-solid mixture, and performing liquid-solid separation to obtain a desolidified oil liquid and a wax paste, wherein the diluent is a C3-C6 fatty ketone; (3) removing the diluent from the desolidified oil liquid to obtain a catalytic cracking oil slurry depleted of 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 solids removal rate of the catalytic cracking oil slurry is greater than 86%.

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 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. This process involves partially recycling and blending the reaction products extracted from the distillation tower, with the remaining fraction discharged from the unit to maintain the unit's thermal balance and processing capacity. This portion of slurry 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. It possesses 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. The content of catalyst fines is determined by solids content measurement, typically ranging 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 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 and device for removing solid matter from catalytic oil slurry on the basis of the existing technology.

[0006] In a first aspect, the present invention provides a method for removing solids from a 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 petroleum wax and / or synthetic wax, the carbon number of which is between C16 and C35, and the mass content of normal alkanes is 70 to 85%;

[0008] (2) mixing a diluent with the raw oil liquid in step (1), cooling to obtain a liquid-solid mixture, and performing liquid-solid separation to obtain a desolidified oil liquid and wax paste; the diluent is selected from C3-C6 fatty ketones;

[0009] (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.

[0010] In a second aspect, the present invention provides a device for removing solid matter from catalytic cracking oil slurry, comprising a mixing unit, a crystallization unit, a liquid-solid separation unit and a solvent separation unit connected in sequence, wherein the mixing unit is a stirred tank, a pipeline pump or a static mixer; the liquid-solid separation unit is a filtering device; and the solvent separation unit is a distillation tower.

[0011] The beneficial effects of the method and device for reducing the solid content in catalytic cracking oil slurry provided by the present invention are:

[0012] 1) A phase change material is added to the catalytic cracking oil slurry. The phase change material is liquid above the melting point, dissolves into the catalytic oil slurry, and converts to a solid state during the cooling process, grabbing the catalyst particles to form solid wax crystal particles; 2) A low-carbon, high-normal alkane content additive can crystallize at a lower temperature and grow to form larger crystals; 3) A low-carbon fatty ketone diluent increases the distance between alkane crystals, which helps the alkane crystals grow uniformly, and its low solubility in the crystals makes it easy to precipitate from the solution; 4) The diluent added to the oil liquid of the raw oil and the additive helps to reduce the viscosity of the solution and increase the filtration separation speed; 5) The filter layer formed by the wax crystals during the filtration separation process serves to further intercept the catalyst powder; 6) After the additive and diluent added in the desolidification step are recovered, the diluent is 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 86%, and the solid content of the catalytic cracking slurry after solid removal can be as low as 0.01% by weight.

[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 The present invention is a flow diagram of a method for removing solids from 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] In a first aspect, the present invention provides a method for removing solids from a catalytic cracking oil slurry, comprising:

[0023] (1) mixing an additive with a raw oil and heating it to obtain a raw oil liquid, wherein the additive is petroleum wax and / or synthetic wax, the carbon number of which is between C16 and C35, and the mass content of normal alkanes is 70 to 85%;

[0024] (2) mixing a diluent with the raw oil liquid in step (1), cooling to obtain a liquid-solid mixture, and performing liquid-solid separation to obtain a desolidified oil liquid and wax paste; the diluent is selected from C3-C6 fatty ketones;

[0025] (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.

[0026] In the method provided by the present invention, the raw oil is the portion obtained by cutting and separating the light components from the heavy oil catalytic reaction product.

[0027] 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, or a static mixer to stir and mix the raw oil and the additive to obtain 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.

[0028] The auxiliary agent in step (1) is petroleum wax and / or synthetic wax. The petroleum wax refers to paraffin wax obtained from natural petroleum. The synthetic wax refers to artificially synthesized wax, such as the wax produced as a by-product when synthesizing artificial petroleum by the Fischer-Tropsch process or the wax obtained by catalytic polymerization of ethylene. Its main components are straight-chain alkanes, as well as a small amount of alkanes with individual branches and monocyclic hydrocarbons with long side chains. Cycloalkanes .

[0029] The auxiliary agent in step (1) has a carbon number between C16 and C35, and a normal alkane content of 70 to 85% by weight; preferably, the auxiliary agent has a carbon number between C18 and C33, and a normal alkane content of 74 to 79% by weight. The petroleum wax and / or synthetic wax is solid at room temperature, with a melting point of 38 to 55°C, more preferably 40 to 53°C.

[0030] 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 50 to 70° C., preferably, the mixing temperature of the additive and the raw oil is 55 to 65° C.

[0031] The amount of the additive in step (1) is 0.5-25% by weight of the raw oil, preferably 3-20% by weight of the raw oil, and more preferably 5-15% by weight 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.

[0032] In the method provided by the present invention, in step (2), the diluent is selected from C3-C6 aliphatic ketones, selected from one or more of acetone, butanone, pentanone, and octanone. Preferably, the diluent is a mixture of acetone and butanone, or butanone, wherein the volume ratio of acetone to butanone is 0-30:70-100; butanone is further preferred.

[0033] The diluent is further mixed evenly with the raw oil obtained in step (1), and at the same time 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, and the solid-liquid separation is carried out at the 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 respectively obtained. 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 feedstock oil is 0.5 to 3.0, preferably 0.8 to 2.5, and more preferably 1 to 2.0.

[0035] 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. Preferably, the amount of the first diluent added is 17-50% of the total diluent.

[0036] Preferably, the mixing temperature of the first diluent added to the raw oil in step (2) is 50-70° C., preferably 55-65° C. After adding the first diluent and mixing, a raw oil containing diluent is obtained. The raw oil containing diluent is cooled to 15-35° C., preferably 20-30° C., and the second diluent is added. The temperature is further lowered to the separation temperature before solid-liquid separation is performed. The separation temperature is -30-0° C., preferably -25--5° C., and more preferably -20--10° C.

[0037] 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. Too fast a cooling rate can lead to poor crystallization, difficult filtration, and inability to achieve 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] In a second aspect, the present invention provides a device for removing solid matter from catalytic cracking oil slurry, comprising a mixing unit, a crystallization unit, a liquid-solid separation unit and a solvent separation unit connected in sequence, wherein the mixing unit is selected from a stirred tank, a pipeline pump or a static mixer; the liquid-solid separation unit is a filtering device; and the solvent separation unit is a distillation device.

[0041] The present invention provides a method for removing solids from catalytic cracking oil slurry. The method comprises adding a C18-C33 hydrocarbon additive having a mass content of 74-79% normal alkanes to a raw oil, dissolving the additive into the raw oil under mixing conditions, and uniformly mixing the additive-containing oil 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. After separation and diluent removal, a catalytic cracking oil slurry with reduced solids content and the additive containing solids are obtained. The C3-C6 fatty ketone diluent facilitates crystallization of the C18-C33 normal alkanes dissolved in the solution during the cooling process, forming wax crystals of the catalyst and additive. These wax crystals are then retained under filtration separation conditions, thereby achieving the purpose of reducing the solids content in the catalytic oil slurry. The catalytic oil slurry from which solids have been removed is an excellent raw material for manufacturing carbon black, petroleum coke, and aromatics extraction to produce rubber additives or asphalt softeners.

[0042] The specific embodiments of the present invention are described clearly and completely below with reference to the accompanying drawings.

[0043] Attachment Figure 1 The present invention provides a schematic flow diagram of a method for removing solids from catalytic cracking slurry. Figure 1 As 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.

[0044] 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.

[0045] 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.

[0046] In the Examples and Comparative Examples:

[0047] Feedstock A was obtained from the catalytic cracking unit of Fujian Refining and Chemical Company; feedstock B was obtained from the catalytic cracking unit of Sinopec Jiujiang Refining and Chemical Company; and feedstock C was obtained from the catalytic cracking unit of Sinopec Shijiazhuang Company. Their properties are shown in Table 1.

[0048] Additive A is petroleum wax obtained from Shanghai Gaoqiao Branch of Sinopec; additive B is Fischer-Tropsch wax obtained from Inner Mongolia Yitai Chemical Company. The properties are shown in Table 2.

[0049] Example 1

[0050] (1) The additive A and the raw oil A are mixed uniformly at 60°C to obtain a raw oil liquid containing the additive. The amount of additive A added is 5% by weight of the raw oil.

[0051] (2) Using butanone 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, and the liquid-solid mixture formed is filtered and separated at -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 60°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 1.5; the cooling rate is 2°C / min, and the mass ratio of the flushing agent to the raw oil is 0.5.

[0052] (3) The desolidified oil liquid and the solid wax paste were fractionated at 90°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 1140.5 kg / m 3 , the kinematic viscosity at 100℃ is 69.97mm 2 / s, the residual carbon value is 14.48%. Other results are shown in Table 3. The calculation formula for the parameters in Table 3 is:

[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 × desolidified oil slurry yield ÷ 100) ÷ mass of solids in crude oil × 100%.

[0055] Example 2

[0056] (1) The additive A and the raw oil B were mixed uniformly at 55° C. to obtain a raw oil liquid containing the additive. The amount of additive A added was 10% by weight of the raw oil.

[0057] (2) Using butanone as a diluent and a flushing agent, the diluent was added to the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture was filtered and separated at -15°C. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a solid wax paste. The temperature of the first addition of the diluent was 55°C and the dilution ratio was 0.5; the temperature of the second addition of the diluent was 20°C and the dilution ratio was 0.5. The cooling rate was 1.5°C / min, and the mass ratio of the flushing agent to the raw oil B was 0.5.

[0058] (3) The desolidified oil liquid and the solid wax paste were fractionated at 90℃ 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℃ was 1107.4kg / m 3 , 100℃ kinematic viscosity 21.09mm 2 / s, carbon residue value was 9.60%. Other results are shown in Table 3.

[0059] Comparative Example 1

[0060] (1) Using raw oil B without adding additives;

[0061] (2) Using butanone as a diluent and a flushing agent, the diluent was added to the crude oil B twice to obtain a homogeneous mixture. The liquid-solid mixture was filtered and separated at -15°C. 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 55°C and a dilution ratio of 0.5. The second addition of the diluent was at a temperature of 20°C and a dilution ratio of 0.5. The cooling rate was 1.5°C / min. The mass ratio of the flushing agent to the crude oil B was 0.5.

[0062] (3) The desolidified oil liquid and the solid wax paste were fractionated at 90°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 1111.4 kg / m 3 , the kinematic viscosity at 100℃ is 23.05mm 2 / s, carbon residue value 10.32%, other results are shown in Table 3.

[0063] Example 3

[0064] (1) The additive B and the raw oil B are mixed uniformly at 68° C. to obtain a raw oil liquid containing the additive. The amount of additive B added is 20% of the raw oil.

[0065] (2) Using butanone as a diluent and a flushing agent, the diluent was added to the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture was filtered and separated at -5°C. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a solid wax paste. The first addition of the diluent was at a temperature of 68°C and a dilution ratio of 0.5. The second addition of the diluent was at a temperature of 15°C and a dilution ratio of 2.5. The cooling rate was 3.5°C / min. The mass ratio of the flushing agent to the raw oil was 0.5.

[0066] (3) The desolidified oil liquid and the solid wax paste were fractionated at 90℃ to remove the diluent, and the desolidified oil slurry and the solid additive were obtained respectively. After analysis, the density of the desolidified oil slurry at 20℃ was 1109.9kg / m 3 , 100℃ kinematic viscosity 28.41mm 2 / s, carbon residue value was 10.59%. Other results are shown in Table 3.

[0067] Example 4

[0068] (1) The additive A and the raw oil C were mixed uniformly at 50°C to obtain a raw oil liquid containing the additive. The amount of additive B added was 3% by mass of the raw oil.

[0069] (2) A mixture of acetone and butanone was used as a diluent and a flushing agent, wherein the volume fraction of acetone was 20%. The diluent was added to the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture was cooled to 0°C and filtered to separate it. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a solid wax paste. The first addition of the diluent was at a temperature of 50°C and a dilution ratio of 0.4. The second addition of the diluent was at a temperature of 35°C and a dilution ratio of 0.4. The cooling rate was 1°C / min. The mass ratio of the flushing agent to the raw oil was 0.5.

[0070] (3) The desolidified oil liquid and the solid wax paste were fractionated at 90℃ to remove the diluent, and the desolidified oil slurry and the solid additive were obtained respectively. After analysis, the density of the desolidified oil slurry at 20℃ was 1142.6kg / m 3 , 100℃ kinematic viscosity 33.78mm 2 / s, residual carbon value 11.98%, other results are shown in Table 3.

[0071] Example 5

[0072] (1) The additive B and the raw oil C were mixed uniformly at 65° C. to obtain a raw oil liquid containing the additive. The amount of additive B added was 15% by mass of the raw oil.

[0073] (2) Using butanone as a diluent and a flushing agent, the diluent was added to the raw oil liquid twice to obtain a raw oil liquid containing the diluent. The liquid-solid mixture was filtered and separated at -10°C. The filter cake was rinsed with the flushing agent to obtain a desolidified oil liquid and a solid wax paste. The first addition of the diluent was at a temperature of 60°C and a dilution ratio of 0.5. The second addition of the diluent was at a temperature of 25°C and a dilution ratio of 1. The cooling rate was 3°C / min. The mass ratio of the flushing agent to the raw oil was 0.5.

[0074] (3) After the desolidified filtrate and the solid wax paste were fractionated at 90℃ to remove the diluent, the desolidified oil slurry and the solid additive were obtained respectively. After analysis, the density of the desolidified oil slurry at 20℃ was 1143.5kg / m 3 ,100℃ kinematic viscosity 34.08mm 2 / s, carbon residue value 12.09%, other results are shown in Table 3.

[0075] Table 1

[0076] project Crude Oil A Crude oil B Crude oil C Analytical methods <![CDATA[Density (20 °C) / (kg / m 3 )]]> 1141.9 1105.6 1145.5 GB / T 13377 <![CDATA[Kinematic viscosity (100 °C) / (mm 2 / s)]]> 66.91 16.36 30.69 GB / T 265 Residual carbon value / % 13.8 9.5 12.15 GB / T 17144 Oil slurry solid content / wt% 0.15 0.26 0.54 Q / SH 0741 Sulfur content / wt% 0.88 0.828 0.999 GB / T 17040 Nitrogen content / (mg / kg) 1400 / / GB / T 0704 Nitrogen content / wt% / 0.25 0.11 GB / T 0704

[0077] Table 2

[0078] project Additive A Additive B Analytical methods Petroleum wax synthetic wax Carbon number of normal alkanes C22~C33 C18~C33 SH / T 0889 Normal alkane content / wt% 79.0 74.5 SH / T 0889 Melting point / ℃ 53.4 41.2 GB / T 2539 <![CDATA[Kinematic viscosity at 100℃ / (mm 2 / s)]]> 3.248 2.352 GB / T 265

[0079] Table 3

[0080] project Example 1 Example 2 Comparative Example 1 Example 3 Example 4 Example 5 crude oil A B B B C C additives A A / B A B Desolidified oil slurry yield / % 97.8 96.3 98.8 87.5 98.2 95.2 Desolidified oil slurry solid content / wt% 0.01 0.03 0.20 0.04 0.06 0.03 Solid removal rate / % 93.5 88.9 24.0 86.5 89.1 94.7

[0081] The results of Comparative Example 1 and Example 2 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 solids removal from catalytic slurry without the additive, the resulting desolidified slurry has a lower solids content.

[0082] The results of Examples 1-5 demonstrate that the present method achieves a slurry oil solids removal rate of 86.5% to 94.7%, 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-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, making it a green technology.

Claims

1. A method for removing solids from catalytic cracking slurry, characterized in that: include: (1) mixing an additive with a catalytic cracking oil slurry raw material and heating the mixture to obtain a raw oil liquid, wherein the additive is a petroleum wax and / or a synthetic wax having a carbon number between C18 and C33 and a normal alkane mass content of 70 to 85%; (2) mixing a diluent with the raw oil liquid in step (1), cooling to obtain a liquid-solid mixture, and performing liquid-solid separation to obtain a desolidified oil liquid and wax paste; the diluent is a C3-C6 fatty ketone, and the mass ratio of the diluent to the catalytic cracking oil slurry raw material is 0.5-3.0; (3) After removing the diluent from the desolidified oil liquid, a catalytic cracking oil slurry free of solids is obtained. After removing the diluent from the wax paste, an additive containing solids is obtained. The additive containing solids is returned to the catalytic cracking unit as a raw material.

2. The method for removing solids from catalytic cracking oil slurry according to claim 1, characterized in that: The mass content of normal alkanes in the auxiliary agent is 74-79%.

3. The method for removing solids from catalytic cracking oil slurry according to claim 1 or 2, characterized in that: In step (1), the mixing temperature of the additive and the catalytic cracking oil slurry raw material is 50-70°C.

4. The method for removing solids from catalytic cracking oil slurry according to claim 3, characterized in that: In step (1), the mixing temperature of the additive and the catalytic cracking oil slurry raw material is 55-65°C.

5. The method for removing solids from catalytic cracking oil slurry according to claim 1 or 2, characterized in that: The amount of the additive added in step (1) is 0.5-25% by weight of the catalytic cracking slurry raw material.

6. The method for removing solids from catalytic cracking oil slurry according to claim 5, characterized in that: The amount of the additive added in step (1) is 3 to 20% by weight of the catalytic cracking slurry raw material.

7. The method for removing solids from catalytic cracking oil slurry according to claim 6, characterized in that: The amount of the additive added in step (1) is 5-15% by weight of the catalytic cracking slurry raw material.

8. The method for removing solids from catalytic cracking oil slurry according to claim 1 or 2, characterized in that: The diluent is a mixture of acetone and butanone, or butanone, wherein the volume ratio of acetone to butanone is 0-30:70-100.

9. The method for removing solids from catalytic cracking oil slurry according to claim 8, characterized in that: The diluent is butanone.

10. The method for removing solids from catalytic cracking oil slurry according to claim 1 or 2, characterized in that: The mass ratio of the diluent to the catalytic cracking oil slurry raw material is 0.8-2.

5.

11. The method for removing solids from catalytic cracking oil slurry according to claim 10, characterized in that: The mass ratio of the diluent to the catalytic cracking oil slurry raw material is 1-2.

0.

12. The method for removing solids from catalytic cracking oil 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 first diluent added is 17-50% of the total diluent.

13. The method for removing solids from catalytic cracking oil slurry according to claim 12, characterized in that: In step (2), the temperature of adding the first diluent to the raw oil liquid is 50~70°C; the temperature of adding the second diluent is 15~35°C; and the liquid-solid separation temperature is -30~0°C.

14. The method for removing solids from catalytic cracking oil slurry according to claim 13, characterized in that: In step (2), the temperature of the first diluent added to the raw oil liquid is 55~65°C, and the temperature of the second diluent added is 20~30°C; the liquid-solid separation temperature is -25~-5°C.

15. The method for removing solids from catalytic cracking oil slurry according to claim 14, characterized in that: The liquid-solid separation temperature in step (2) is -20~-10℃.

16. The method for removing solids from catalytic cracking oil slurry according to claim 1 or 2, characterized in that: The cooling rate of the mixture of the raw oil and the diluent is 0.5~4℃ / min.

17. The method for removing solids from catalytic cracking oil slurry according to claim 16, characterized in that: The cooling rate is 1-3.5°C / min.

18. The method for removing solids from catalytic cracking oil slurry according to claim 17, characterized in that: The cooling rate is 1.5-3°C / min.

Images