Preparation method of residual oil hydrothermal cracking catalyst, catalyst and cracking method
By preparing a hydrothermal pyrolysis catalyst for residual oil, the high cost of hydrothermal catalysts was solved by utilizing the porous structure of aged cold-rolled sludge and the catalytic activity of complex iron-organic compounds, thus achieving efficient viscosity reduction and resource utilization of residual oil.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-13
AI Technical Summary
Among existing residual oil treatment technologies, hydrothermal catalysts are costly and complex to prepare, while traditional viscosity reduction methods are energy-intensive or expensive, have short catalyst lifespans, and suffer from poisoning problems.
A hydrothermal pyrolysis catalyst for residual oil was prepared by mixing aged cold-rolled sludge with sludge detergent and then mechanically stirring and ultrasonically washing. The catalyst utilizes the porous structure and catalytic activity of complex iron-organic compounds in the aged cold-rolled sludge to reduce the viscosity of residual oil in combination with the hydrothermal reaction.
It achieves low-cost and high-efficiency hydrothermal pyrolysis of residual oil, reduces the viscosity of residual oil, makes resource-efficient use of cold-rolled sludge, and simplifies the preparation process.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of residual oil treatment technology, and particularly relates to a method for preparing a residual oil hydrothermal pyrolysis catalyst, the catalyst, and the pyrolysis method. Background Technology
[0002] Oil is one of the most important energy sources in the world today, and with the ever-increasing energy demand, countries around the world are becoming increasingly dependent on oil and gas resources. Residual oil is the residue extracted from the bottom of refinery towers after atmospheric or vacuum distillation of crude oil. It constitutes a significant proportion of crude oil in most of my country's major oil fields, but its actual usability is low. Residual oil has a high density and viscosity, poor fluidity, and high sulfur content. Without viscosity-reducing treatment, both subsequent transportation and reuse become extremely complex.
[0003] Traditional viscosity reduction methods include chemical and physical methods. Heating-based viscosity reduction is currently the most common chemical method, but it is energy-intensive and results in significant oil loss. Physical viscosity reduction, such as dilution, involves adding a certain amount of light oil to heavy oil, thus reducing its viscosity. While this method has lower energy consumption, the subsequent pipeline construction and operation costs are high, increasing industrial costs. Residue hydrotreating, as a relatively new viscosity reduction technology, can address the shortcomings of traditional methods. Residue hydrocracking and catalytic cracking technologies can decompose residue into smaller molecules, reducing the content of impurities such as sulfur and nitrogen, while significantly reducing residue viscosity, and even producing common chemical feedstocks such as automotive oils. However, these technologies suffer from high energy consumption, short catalyst life, and catalyst poisoning. Hydrothermal catalytic cracking is a relatively new residue treatment technology. It uses high-temperature, high-pressure water and a catalyst to decompose residue into smaller molecules, significantly reducing its viscosity. However, the catalysts used in the hydrothermal catalytic cracking reaction are currently quite expensive. Summary of the Invention
[0004] The purpose of this invention is to provide a hydrothermal pyrolysis catalyst for residual oil, which is low in cost and simple to prepare.
[0005] The technical solution of this invention is as follows:
[0006] A method for preparing a hydrothermal pyrolysis catalyst for residual oil includes the following steps:
[0007] Step 1: Mix aged cold-rolled sludge with sludge detergent at a mass ratio of 1:2 to 10, mechanically stir and ultrasonically wash.
[0008] Step 2: Separate and remove the liquid phase; dry the resulting solid phase to remove surface moisture, and obtain the residual oil hydrothermal pyrolysis catalyst;
[0009] The aged cold-rolled sludge is the aged cold-rolled sludge produced during the rolling of steel.
[0010] Cold-rolled sludge produced during steel rolling is heated and dehydrated to become aged cold-rolled sludge. Aged cold-rolled sludge has high viscosity and contains iron in multiple valence states. Some of this iron reacts with organic matter in the sludge to form complex organic iron compounds. In the method of this invention, the aged cold-rolled sludge is mixed with a sludge detergent in step one. During mechanical stirring and washing, the aged cold-rolled sludge continuously generates new contact surfaces with the detergent. Some of the oily substances adhering to the contact surfaces between the aged cold-rolled sludge and the detergent are emulsified and washed away in the aqueous phase. Repeated mechanical stirring and washing result in a porous or multi-channel structure with a large specific surface area in the aged cold-rolled sludge. Simultaneously, more complex organic iron compounds are exposed on the surface of the aged cold-rolled sludge, increasing the effective contact area between these complex organic iron compounds and the external environment. After drying in step two to remove surface moisture, the surface of the resulting residue oil hydrothermal pyrolysis catalyst becomes more porous due to the evaporation of water molecules. These complex iron-organic compounds present in the pores or other surfaces catalyze the hydrothermal pyrolysis reaction, giving the aged cold-rolled sludge the activity of catalyzing the hydrothermal pyrolysis reaction.
[0011] Preferably, the power density of the ultrasonic waves in the ultrasonic washing process is 300–1000 W / cm². 2 The frequency is 15-25KHz, and the ultrasonic treatment time is 0.5-1h.
[0012] The cavitation effect of ultrasound effectively removes grease and other substances adhering to the surface of aged cold-rolled sludge, resulting in high washing efficiency. (300–1000 W / cm²) 2 An ultrasonic power and frequency of 15–25 kHz is sufficient to effectively remove oily substances adhering to the surface of aged cold-rolled sludge, resulting in a larger specific surface area and full exposure of complex iron-organic compounds, without disintegrating the porous structure of the sludge. The ultrasonic treatment time should not be too long, as excessively long ultrasonic treatment will damage the porous structure of the aged cold-rolled sludge and cause excessive vibration of the oil contaminants in the entire washing system. This will cause the oil contaminants to re-adhere to the metal and its ligand surfaces, reducing catalytic activity.
[0013] Preferably, the oil sludge detergent has the following composition by mass: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
[0014] The aforementioned sludge detergent can effectively remove the oily substances adhering to the surface of aged cold-rolled sludge, maintaining the porous structure of the solid phase after washing. Of course, other sludge detergents can also be used, as long as they can remove the floating oil from the surface of the aged sludge, exposing the complex iron-containing organic compounds within the sludge, which possess catalytic activity for hydrothermal reactions.
[0015] Preferably, the aged cold-rolled sludge is prepared by the following method: the cold-rolled sludge produced by rolling steel is centrifuged to remove free water, and the resulting viscous oily substance is heated and dehydrated under mechanical stirring. During the heating process, circulating hot air is introduced, and the temperature of the hot air is 150-200℃. When the moisture content is below 30%, the aged cold-rolled sludge is obtained.
[0016] In the above method, the cold-rolled sludge produced during steel rolling, after removing free water, becomes a black, viscous oily substance. This viscous oily substance is heated and dehydrated under mechanical stirring, while circulating hot air at a temperature of 150-200℃ is introduced. During this process, the cold-rolled sludge continuously dehydrates, is heated, and comes into full contact with oxygen in the air. The micron- or nano-sized iron and iron oxide contained in the cold-rolled sludge come into full contact with mineral oil, fatty acids, petroleum sulfonates, and polyesters, and react at high temperatures. When the moisture content of the cold-rolled sludge reaches below 30%, it ages, generating complex iron-organic compounds. The introduction of circulating air helps provide oxygen to complete the oxidation reaction, causing the sludge to age rapidly and carrying away the evaporated water. The temperature of 150-200℃ is beneficial for giving the aged sludge catalytic activity.
[0017] This invention also provides a hydrothermal pyrolysis catalyst for residual oil, prepared by the above method. Preferably, the iron content is 0.5-30.0 wt%.
[0018] Insufficient iron content results in low or even non-active activity in the prepared hydrothermal pyrolysis catalyst for residual oil.
[0019] The present invention also provides a method for hydrothermal cracking of residual oil, comprising the following steps:
[0020] Step 1: Mix the residue oil with water and add the residue oil hydrothermal pyrolysis catalyst as described in claim 5 or 6, emulsifying it into an emulsion mixture;
[0021] Step 2: Place the emulsified mixture in a reactor and maintain the temperature at 300-340℃ and the pressure at 2.8-3.2MPa for hydrothermal catalytic cracking for 2-3 hours; wherein the mass ratio of residue oil, water and residue oil hydrothermal cracking catalyst is 10:2-4:0.05-0.3.
[0022] In the method of this invention, the residue oil is first mixed and emulsified with water to ensure sufficient dispersion and contact between the residue oil and water, which is beneficial for the efficient and thorough hydrothermal catalytic cracking reaction. Preferably, the emulsifier used in the emulsification is sodium alkylbenzene sulfonate, and the amount used is 1-5% of the mass of the residue oil. The emulsification process can be carried out using a high-speed shear emulsifier for high-speed shear mixing, and a co-emulsifier can also be added.
[0023] The beneficial effects of this invention are as follows:
[0024] This invention provides a simple method for preparing a hydrothermal pyrolysis catalyst for residual oil. It utilizes cold-rolled sludge generated during steel rolling, resulting in low cost, turning waste into treasure, and realizing the resource utilization of cold-rolled sludge. The prepared hydrothermal pyrolysis catalyst can catalyze the hydrothermal pyrolysis reaction of residual oil, thereby reducing the viscosity of the residual oil. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the embodiments.
[0026] The cold-rolled sludge used in the following embodiments and comparative examples is a viscous oily cold-rolled sludge obtained by centrifuging the mixture of cold-rolled sludge produced from rolling steel and removing free water.
[0027] The raw material residue oil used in the following embodiments and comparative examples is Anqing Petrochemical residue oil, and the properties of the residue oil are shown in Table 1.
[0028] Table 1
[0029] Project / Unit numerical values Viscosity (100℃) / mPa·s 8787 <![CDATA[Density (20 °C) / g·cm -3 > 0.972 Ash content (mass fraction) / % 0.026 Carbon mass fraction / % 85.96 Hydrogen mass fraction / % 9.975 Sulfur mass fraction / % 1.824 Nitrogen mass fraction / % 0.81 <![CDATA[Nickel / μg·g -1 > 9.36 <![CDATA[Vanadium / μg·g -1 > 65.54 <![CDATA[Calcium / μg·g -1 > 33.85 <![CDATA[Magnesium / μg•g -1 > 4.6 <![CDATA[Iron / μg·g -1 > 12.96 <![CDATA[Copper / μg·g -1 > 0.27 Saturated fraction / wt% 23.67 Aromatic components / wt% 37.62 Gel / wt / % 32.59 Asphalt / wt% 6.12
[0030] Example 1
[0031] 1. A hydrothermal pyrolysis catalyst for residual oil is prepared by the following method:
[0032] Step 1: Prepare and wash aged cold-rolled sludge.
[0033] Oil sludge aging: Cold-rolled oil sludge, after centrifugation to remove free water, is added to a reactor and stirred using a propeller agitator. It is then heated to remove water at a temperature of 180-200℃. During heating, circulating hot air is introduced at a temperature of 180℃. Heating is stopped when the moisture content reaches 25%-28%, and the aged cold-rolled oil sludge is obtained.
[0034] Prepare the sludge detergent according to the following mass ratio: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
[0035] Washing: The obtained aged cold-rolled sludge was mixed with sludge detergent at a mass ratio of 1:5, and mechanically stirred using a propeller agitator while simultaneously undergoing ultrasonic washing. The power density of the ultrasonic waves during ultrasonic washing was 500 W / cm³.2 The frequency is 20 kHz, and the ultrasonic washing time is 45 minutes.
[0036] Step 2: Separation and removal of the liquid phase. The obtained solid is vacuum dried in an oven for 30 minutes to remove surface moisture, yielding the residual oil hydrothermal pyrolysis catalyst.
[0037] 2. The residue oil is catalytically cracked using the residue oil hydrothermal pyrolysis catalyst prepared above, as follows:
[0038] Step 1: Heat the residual oil to achieve a slightly fluid consistency. Pour the slightly fluid residual oil into a mixing drum and stir at a constant temperature of 80°C and a stirring speed of 250 rpm.
[0039] Sodium dodecylbenzenesulfonate emulsifier was added at 3% of the mass of the residue oil, and sodium carboxymethyl cellulose stabilizer was added at 1% of the mass of the residue oil. The mixture was then emulsified with water. After emulsification, the aforementioned prepared residue oil hydrothermal pyrolysis catalyst was added, wherein the mass ratio of residue oil, water, and residue oil hydrothermal pyrolysis catalyst was 10:2:0.05.
[0040] Step 2: Place the emulsified mixture in a reaction vessel and maintain a temperature of 320°C and a pressure of 3.0 MPa for hydrothermal catalytic cracking for 2.5 hours to obtain cracked oil after catalytic cracking.
[0041] Example 2
[0042] 1. A hydrothermal pyrolysis catalyst for residual oil is prepared by the following method:
[0043] Step 1: Prepare and wash aged cold-rolled sludge.
[0044] Oil sludge aging: Cold-rolled oil sludge, after centrifugation to remove free water, is added to a reactor and stirred using a propeller agitator. It is then heated to remove water at a temperature of 150-180℃. During heating, circulating hot air is introduced at a temperature of 150℃. Heating is stopped when the moisture content reaches 25%-28%, and the aged cold-rolled oil sludge is obtained.
[0045] Prepare the sludge detergent according to the following mass ratio: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
[0046] Washing: The obtained aged cold-rolled sludge was mixed with sludge detergent at a mass ratio of 1:10, and mechanically stirred using a propeller agitator while simultaneously undergoing ultrasonic washing. The power density of the ultrasonic waves during ultrasonic washing was 300 W / cm³. 2 The frequency is 25 kHz, and the ultrasonic washing time is 30 minutes.
[0047] Step 2: Separation and removal of the liquid phase. The obtained solid is vacuum dried in an oven for 30 minutes to remove surface moisture, yielding the residual oil hydrothermal pyrolysis catalyst.
[0048] 2. The residue oil is catalytically cracked using the residue oil hydrothermal pyrolysis catalyst prepared above, as follows:
[0049] Step 1: Heat the residual oil to achieve a slightly fluid consistency. Pour the slightly fluid residual oil into a mixing drum and stir at a constant temperature of 80°C and a stirring speed of 350 rpm.
[0050] Sodium lignosulfonate emulsifier was added at 1% of the mass of the residue oil, and sodium carboxymethyl cellulose stabilizer was added at 2% of the mass of the residue oil. The mixture was then emulsified with water. After emulsification, the aforementioned prepared residue oil hydrothermal pyrolysis catalyst was added, wherein the mass ratio of residue oil, water, and residue oil hydrothermal pyrolysis catalyst was 10:4:0.3.
[0051] Step 2: Place the emulsified mixture in a reaction vessel and maintain a temperature of 340°C and a pressure of 2.8 MPa for hydrothermal catalytic cracking for 2.0 hours to obtain cracked oil after catalytic cracking.
[0052] Example 3
[0053] 1. A hydrothermal pyrolysis catalyst for residual oil is prepared by the following method:
[0054] Step 1: Prepare and wash aged cold-rolled sludge.
[0055] Oil sludge aging: Cold-rolled oil sludge, after centrifugation to remove free water, is added to a reactor and stirred using a propeller agitator. It is then heated to remove water at a temperature of 190-200℃. During heating, circulating hot air is introduced at a temperature of 190℃. Heating is stopped when the moisture content reaches 20%-25%, and the aged cold-rolled oil sludge is obtained.
[0056] Prepare the sludge detergent according to the following mass ratio: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
[0057] Washing: The obtained aged cold-rolled sludge was mixed with sludge detergent at a mass ratio of 1:2, and mechanically stirred using a propeller agitator while simultaneously undergoing ultrasonic washing. The power density of the ultrasonic waves during ultrasonic washing was 1000 W / cm³. 2 The frequency is 15 kHz, and the ultrasonic washing time is 60 minutes.
[0058] Step 2: Separation and removal of the liquid phase. The obtained solid is vacuum dried in an oven for 30 minutes to remove surface moisture, yielding the residual oil hydrothermal pyrolysis catalyst.
[0059] 2. The residue oil is catalytically cracked using the residue oil hydrothermal pyrolysis catalyst prepared above, as follows:
[0060] Step 1: Heat the residual oil to achieve a slightly fluid consistency. Pour the slightly fluid residual oil into a mixing drum and stir at a constant temperature of 80°C and a stirring speed of 250 rpm.
[0061] Sodium dodecylbenzenesulfonate emulsifier was added at 5% of the mass of the residue oil, and sodium carboxymethyl cellulose stabilizer was added at 1% of the mass of the residue oil. The mixture was then emulsified with water. After emulsification, the aforementioned prepared residue oil hydrothermal pyrolysis catalyst was added, wherein the mass ratio of residue oil, water, and residue oil hydrothermal pyrolysis catalyst was 10:4:0.05.
[0062] Step 2: Place the emulsified mixture in a reaction vessel and maintain a temperature of 300℃ and a pressure of 3.2 Pa for hydrothermal catalytic cracking for 3.0 hours to obtain cracked oil after catalytic cracking.
[0063] Example 4
[0064] 1. A hydrothermal pyrolysis catalyst for residual oil is prepared by the following method:
[0065] Step 1: Prepare and wash aged cold-rolled sludge.
[0066] Sludge aging: Cold-rolled sludge, after being centrifuged to remove free water, is added to a reactor and stirred using a propeller agitator. It is then heated to remove water at 160-180℃. During heating, circulating hot air is introduced at 170℃. Heating is stopped when the moisture content reaches 20%-25%, and the aged cold-rolled sludge is obtained.
[0067] Prepare the sludge detergent according to the following mass ratio: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
[0068] Washing: The obtained aged cold-rolled sludge was mixed with sludge detergent at a mass ratio of 1:8, and mechanically stirred using a propeller agitator while simultaneously undergoing ultrasonic washing. The power density of the ultrasonic waves during ultrasonic washing was 800 W / cm³. 2 The frequency is 20 kHz, and the ultrasonic washing time is 30 minutes.
[0069] Step 2: Separation and removal of the liquid phase. The obtained solid is vacuum dried in an oven for 30 minutes to remove surface moisture, yielding the residual oil hydrothermal pyrolysis catalyst.
[0070] 2. The residue oil is catalytically cracked using the residue oil hydrothermal pyrolysis catalyst prepared above, as follows:
[0071] Step 1: Heat the residual oil to achieve a slightly fluid consistency. Pour the slightly fluid residual oil into a mixing drum and stir at a constant temperature of 80°C and a stirring speed of 250 rpm.
[0072] Sodium dodecylbenzenesulfonate emulsifier is added at 5% of the mass of the residue oil, and then emulsified with water. After emulsification, the above-prepared residue oil hydrothermal pyrolysis catalyst is added, wherein the mass ratio of residue oil, water, and residue oil hydrothermal pyrolysis catalyst is 10:3:0.3.
[0073] Step 2: Place the emulsified mixture in a reaction vessel and maintain a temperature of 330°C and a pressure of 3.5 MPa for hydrothermal catalytic cracking for 2.5 hours to obtain cracked oil after catalytic cracking.
[0074] Comparative Example 1
[0075] 1. Preparation of a hydrothermal pyrolysis catalyst for residual oil
[0076] The only difference between this comparative example and Example 1 is in step one. In this comparative example, the cold-rolled sludge after centrifugation to remove free water is directly mixed with a sludge detergent at a mass ratio of 1:5 for washing, without sludge aging. Then, the liquid phase is removed using the same method as in Example 1 to obtain the product.
[0077] 2. The product prepared above is used as a thermal cracking catalyst to catalyze the cracking of residue oil.
[0078] The residual oil and method used are exactly the same as in Example 1.
[0079] Comparative Example 2
[0080] 1. Preparation of a hydrothermal pyrolysis catalyst for residual oil
[0081] This comparative example uses the same method as Example 1 to prepare aged cold-rolled sludge. The only difference between this comparative example and Example 1 is that the aged cold-rolled sludge is not washed in step one. Instead, the aged cold-rolled sludge is directly separated and the liquid phase is removed in step two using the same method as in Example 1. That is, the aged cold-rolled sludge is vacuum dried in an oven for 30 minutes to remove surface moisture and obtain the product.
[0082] 2. The product prepared above is used as a catalyst for the hydrothermal cracking of residual oil.
[0083] The residual oil and method used are exactly the same as in Example 1.
[0084] Comparative Example 3
[0085] Hydrothermal cracking of residual oil without catalyst.
[0086] Step 1: Using the same residual oil as in Example 1, heat-treat it to achieve slight fluidity. Pour the slightly fluid residual oil into a mixing drum and stir at a constant temperature of 80°C and a stirring speed of 250 rpm.
[0087] Sodium dodecylbenzenesulfonate emulsifier was added at 3% of the residue oil mass, and sodium carboxymethyl cellulose stabilizer was added at 1% of the residue oil mass, followed by emulsification with water. The mass ratio of residue oil to water-residue oil hydrothermal cracking catalyst was 10:2.
[0088] Step 2: Place the emulsified mixture in a reaction vessel and perform hydrothermal pyrolysis at a temperature of 320°C and a pressure of 3.0 MPa for 2.5 hours to obtain pyrolyzed oil.
[0089] Detection:
[0090] The viscosity of the pyrolysis oils prepared in each embodiment and comparative example was measured at 100°C using an NDJ-1C viscometer. The test results are shown in Table 2.
[0091] Table 2
[0092] Example Viscosity of feedstock residue oil (mPa·s) Cracked oil viscosity (mPa·s) Viscosity reduction rate (%) Iron content in catalyst (%) Example 1 8787 1754 80.03 49.3 Example 2 8787 2768 68.50 0.56 Example 3 8787 1932 78.01 30.5 Example 4 8787 2934 66.61 20.6 Comparative Example 1 8787 8793 0 49.3 Comparative Example 2 8787 8750 0.41 49.3 Comparative Example 3 8787 8790 0 49.3
[0093] As shown in Table 2, compared to Comparative Example 3 (which did not use a catalyst), Examples 1 to 4, using the hydrothermal pyrolysis catalyst prepared by the method of the present invention, catalyzed the pyrolysis of residual oil, achieving a viscosity reduction rate of over 66.6%. The difference between Comparative Example 1 and Example 1 lies in the fact that the cold-rolled sludge used in preparing the hydrothermal pyrolysis catalyst was not aged. Based on the hydrothermal pyrolysis results of the residual oil, although Comparative Example 1 used the same method as Example 1 for the hydrothermal reaction, it failed to reduce the viscosity of the residual oil. The difference between Comparative Example 2 and Example 1 lies in the fact that the aged cold-rolled sludge was not washed during the preparation of the hydrothermal pyrolysis catalyst; instead, the aged cold-rolled sludge was directly separated and the liquid phase removed for use. Based on the hydrothermal pyrolysis results of the residual oil, the product of Comparative Example 2, used as a catalyst and subjected to the same hydrothermal reaction as Example 1, had almost no effect on reducing the viscosity of the residual oil. Therefore, it is evident that the hydrothermal pyrolysis catalyst for residual oil prepared by the method of the present invention can effectively catalyze the pyrolysis of residual oil in the hydrothermal reaction, reducing the viscosity of the residual oil. The residual oil hydrothermal pyrolysis catalyst prepared by this invention has low cost, simple preparation method, and realizes waste utilization.
[0094] It should be noted that the descriptions of these embodiments are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. In addition, the above are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
Claims
1. A method for preparing a hydrothermal pyrolysis catalyst for residual oil, characterized in that, Includes the following steps: Step 1: Mix aged cold-rolled sludge with sludge detergent at a mass ratio of 1:2 to 10, mechanically stir and ultrasonically wash. Step 2: Separate and remove the liquid phase; dry the resulting solid phase to remove surface moisture, and obtain the residual oil hydrothermal pyrolysis catalyst; The aged cold-rolled sludge is the aged cold-rolled sludge produced during the rolling of steel.
2. The preparation method of the residue oil hydrothermal pyrolysis catalyst according to claim 1, characterized in that, The power density of the ultrasonic waves used in the ultrasonic washing process is 300–1000 W / cm². 2 The frequency is 15-25 kHz, and the ultrasonic treatment time is 0.5-1 hour.
3. The method for preparing the residual oil hydrothermal pyrolysis catalyst as described in claim 1, characterized in that, The composition of the sludge detergent is as follows: 30 parts sodium dodecylbenzenesulfonate, 15 parts nonylphenol polyoxyethylene ether, 0.1 parts sodium silicate, 0.01 parts n-butanol, and 50 parts water.
4. The method for preparing the residue hydrothermal pyrolysis catalyst according to any one of claims 1 to 3, characterized in that, The aged cold-rolled sludge is prepared by the following method: The cold-rolled sludge produced during steel rolling is centrifuged to remove free water. The resulting viscous oily substance is then heated and dehydrated under mechanical stirring. During the heating process, circulating hot air is introduced, and the temperature of the hot air is 150-200℃. When the moisture content is below 30%, aged cold-rolled sludge is obtained.
5. A hydrothermal pyrolysis catalyst for residual oil, characterized in that, Prepared by the method of any one of claims 1 to 4.
6. The residual oil hydrothermal pyrolysis catalyst as described in claim 5, characterized in that, The iron content is 0.5-30.0 wt%.
7. A method for hydrothermal cracking of residual oil, characterized in that, Includes the following steps: Step 1: Mix the residue oil with water and add the residue oil hydrothermal pyrolysis catalyst as described in claim 5 or 6, emulsifying it into an emulsion mixture; Step 2: Place the emulsified mixture in a reactor and maintain the temperature at 300-340℃ and the pressure at 2.8-3.2MPa for hydrothermal catalytic cracking for 2-3 hours; wherein the mass ratio of residue oil, water and residue oil hydrothermal cracking catalyst is 10:2-4:0.05-0.
3.
8. The method for hydrothermal pyrolysis of residual oil as described in claim 7, characterized in that, The emulsifier used in the emulsification is sodium alkylbenzene sulfonate or sodium lignosulfonate, and the amount used is 1 to 5% of the mass of the residue oil.