Catalyst for catalyzing heavy crude oil refining by using natural gas and preparation method thereof

Abstract

The invention discloses a catalyst for catalyzing heavy crude oil refining by using natural gas and a preparation method thereof, and belongs to the technical field of crude oil refining. The invention relates to a catalyst for catalyzing heavy crude oil refining by using natural gas, which is characterized by comprising the following components in percentage by weight according to a formula, the catalyst comprises the following components in percentage by weight: 2-6% of nickel-rhenium bimetallic nanocluster, 3-7% of molybdenum-cerium-boron ternary cocatalyst, 2-5% of titanium nitride or lanthanum oxide plasma response component, 30-45% of silicon dioxide-aluminum oxide-zirconium oxide ternary composite carrier, 10-20% of silicoaluminophosphate molecular sieve shell layer and the balance of solvent or diluent. According to the catalyst disclosed by the invention, a low-carbon alkane component in natural gas is adopted as reaction synergistic gas, and is combined with a multi-metal component to construct a bimetal or multi-metal catalytic system, so that the cracking and conversion efficiency of high-carbon hydrocarbon molecules in heavy crude oil is remarkably improved, and light components such as diesel oil, gasoline and aromatic hydrocarbon can be obtained from the heavy oil with high selectivity.

Description

Technical Field

[0001] The present invention relates to the technical field of crude oil refining, and more particularly to a catalyst for catalyzing the refining of heavy crude oil using natural gas and a preparation method thereof. Background Art

[0002] Heavy crude oil, a low-quality crude oil with high viscosity, high boiling point, and numerous impurities, accounts for a significant portion of global crude oil reserves. With the increasing depletion of light crude oil resources, the efficient utilization of heavy crude oil has become a key research topic in the petrochemical industry. Traditional heavy crude oil processing methods, which often rely on thermal cracking or hydrocracking, suffer from harsh reaction conditions, high energy consumption, poor catalyst selectivity, and the tendency to form coke, severely limiting their economic benefits and industrial applicability.

[0003] In recent years, natural gas, as a clean and efficient energy source and hydrogen source, has shown promise in synergistic utilization in heavy crude oil refining. Introducing natural gas into the catalytic cracking of heavy crude oil not only reduces coke production but also improves reaction selectivity and increases the yield of light oil products through the hydrogen-rich atmosphere. However, the synergistic reaction of natural gas with heavy crude oil is complex, requires delicate reaction conditions, and places high demands on the catalyst's structure and functionality.

[0004] Currently commonly used catalysts such as molecular sieves, metal oxides or composite support catalysts still have the following technical bottlenecks in practical applications: First, the catalysts are prone to sintering and structural collapse under high temperature and high pressure conditions, resulting in reduced activity; second, the catalysts' resistance to carbon deposition and selectivity are insufficient, making it difficult to adapt to the efficient conversion of complex component heavy oils; third, their ability to activate low-carbon alkanes in natural gas is limited, failing to fully utilize the advantages of natural gas synergistic cracking.

[0005] To address these issues, recent research has focused on employing new technologies, such as multimetallic nanocatalytic systems, functional composite supports, and plasma-enhanced reactions, to enhance the stability and reactivity of catalysts under high-temperature reaction conditions. For example, the construction of nanobimetallic clusters using transition metals such as nickel and rhenium can provide higher hydrogen transfer efficiency in synergistic catalysis. The introduction of plasma-responsive components such as cerium oxide and titanium nitride can help enhance the catalyst's ability to activate carbon-hydrogen bonds in natural gas. Furthermore, the construction of molecular sieve coatings can effectively inhibit carbon deposition and agglomeration of the catalyst, extending its service life.

[0006] Furthermore, with the advancement of green and low-carbon development concepts, the environmental friendliness, recyclability, and sustainability of catalyst systems are gaining increasing attention. Therefore, developing a new composite catalyst based on natural gas synergistic reactions that not only efficiently converts heavy crude oil to light oil products but also exhibits excellent thermal stability and environmental adaptability is a key technological path for promoting the integrated development of clean energy and traditional chemical industry. Summary of the Invention

[0007] The object of the present invention is to provide a catalyst for catalyzing the refining of heavy crude oil using natural gas and a preparation method thereof, so as to solve the problems raised in the background technology.

[0008] A catalyst for catalyzing the refining of heavy crude oil using natural gas comprises the following components, measured in percentage by weight: 2-6% nickel-rhenium bimetallic nanoclusters, 3-7% molybdenum-cerium-boron ternary promoter, 2-5% titanium nitride or lanthanum oxide plasma-responsive component, 30-45% silicon dioxide-alumina-zirconium oxide ternary composite carrier, 10-20% silicon aluminum phosphate molecular sieve shell, and the remainder being a solvent or diluent.

[0009] Preferably, the preparation method of the nickel-rhenium bimetallic nanoclusters includes: dissolving nickel nitrate and rhenium trichloride in deionized water in a mass ratio of 3:1, loading them onto a carrier by an impregnation-reduction method, reducing them at 400 degrees Celsius in a hydrogen atmosphere for 4 to 6 hours, cooling to room temperature, centrifuging and drying to obtain nickel-rhenium nanoclusters with a particle size of 2 to 5 nanometers.

[0010] Preferably, the preparation method of the molybdenum-cerium-boron ternary co-catalyst comprises: dissolving a molybdenum source, a cerium source and a boron source in deionized water at a molar ratio of 1:1:0.2 to form a uniform sol, slowly adding the sol to the carrier system, and preparing the sol through stirring, hydrothermal treatment, drying and calcination steps.

[0011] Preferably, the preparation method of the plasma-responsive component includes: doping titanium nitride or lanthanum oxide into a carrier system at a ratio of 2-5% by mass, uniformly mixing, and then calcining at 500 to 600 degrees Celsius for 3 to 5 hours to enhance its surface excitation response ability.

[0012] Preferably, the preparation method of the silica-alumina-zirconium oxide composite carrier includes: adding silica sol, aluminum nitrate and zirconium oxychloride in a molar ratio of 1:1:0.5 to deionized water, adjusting the pH value to 8.5 to 9.0, ultrasonically dispersing and then performing a hydrothermal reaction at 120 to 150 degrees Celsius for 12 hours, and drying and calcining the obtained precursor to obtain a ternary composite carrier with a mesoporous structure.

[0013] Preferably, the coating method of the silicoaluminophosphate molecular sieve shell layer includes: placing the composite catalytic material in a silicoaluminophosphate molecular sieve synthesis solution, crystallizing at 150 to 180 degrees Celsius for 12 to 24 hours, filtering, washing and calcining at 550 degrees Celsius to form a molecular sieve shell layer with a thickness of 10 to 50 nanometers.

[0014] Preferably, the solvent is ethanol or isopropanol, which is used to dissolve the catalytic components and is ultrasonically treated for 20 to 40 minutes to form a nano-uniform dispersion system.

[0015] A process for preparing a catalyst for catalyzing the refining of heavy crude oil using natural gas comprises the following steps: S1, preparing a silica-alumina-zirconia ternary composite support; S2, sequentially loading nickel-rhenium bimetallic clusters, molybdenum-cerium-boron ternary co-catalysts, and titanium nitride or lanthanum oxide response components; S3, constructing a silicoaluminophosphate molecular sieve shell layer on its surface by a hydrothermal coating method; S4. The obtained material is subjected to ultrasonic dispersion, high-temperature calcination and drying under inert gas protection to obtain the target catalyst.

[0016] Compared with the prior art, the advantages of the present invention are: (1) Synergistic catalysis and efficient conversion of heavy crude oil: The catalyst of the present invention uses the low-carbon alkane components in natural gas as the reaction synergistic gas, combined with multi-metal components (such as nickel, rhenium, molybdenum, cobalt, etc.) to construct a bimetallic or multi-metallic catalytic system, which significantly improves the cracking and conversion efficiency of high-carbon hydrocarbon molecules in heavy crude oil, and achieves high selectivity to obtain light components such as diesel, gasoline and aromatics from heavy oil.

[0017] (2) Strengthening the activation ability of natural gas and improving the efficiency of hydrogen transfer: The catalyst introduces a high specific surface area alumina-silica composite carrier and dopes it with co-catalytic components (such as cerium oxide, lanthanum oxide, etc.), which not only enhances the activation ability of carbon-hydrogen bonds in natural gas, but also improves the hydrogen transfer ability in the overall reaction process and reduces the formation of coke by-products.

[0018] (3) Excellent carbon deposition resistance and thermal stability: By applying carbon-nitrogen co-doping coating to the catalyst surface, the catalyst's carbon deposition resistance and structural stability in high-temperature and high-pressure environments are significantly improved, effectively extending the catalyst's service life. Even in long-cycle reactions, the catalyst can still maintain stable activity and selectivity.

[0019] (4) Constructing a porous structure to increase the catalytic specific surface area: The present invention uses molecular sieves or mesoporous materials (such as MCM-41, ZSM-5, etc.) as carriers to construct a three-dimensional pore structure, which increases the exposure of catalytic active sites and is beneficial to the diffusion and contact reaction of large molecular hydrocarbons in heavy oil, thereby improving the overall catalytic efficiency.

[0020] (5) Green preparation process, taking into account both environmental protection and economy: The preparation of the catalyst adopts mild process methods such as sol-gel, self-assembly template, and ultrasound-assisted. The reaction conditions are mild, the energy consumption is low, the process route is simple and controllable, and the amount of inorganic acids and alkalis that are harmful to the environment is reduced. It has good environmental protection and potential for industrial promotion.

[0021] (6) Strong process adaptability and modular application: The catalyst is suitable for various heavy oil processing reactor types such as fixed bed, fluidized bed and slurry bed. It has good process compatibility and flexibility, which facilitates the modular and integrated design of crude oil processing flow to meet the needs of refining of different scales. DETAILED DESCRIPTION

[0022] Example 1: (1) Preparation of carrier γ-Al2O3: Weigh 100g of gamma alumina precursor, add it to 500mL of deionized water, adjust the pH to 7.0, add 0.5g of polyethylene glycol as a structural dispersant, stir at room temperature for 1 hour, then transfer the mixed slurry to a constant temperature drying oven and dry it at 110℃ for 12 hours. The dried material is ground evenly and placed in a muffle furnace and calcined at 550℃ for 6 hours to obtain a pore size of 12nm and a specific surface area of ​​190m 2 / g of γ-Al2O3 carrier powder.

[0023] (2) Preparation of active component solution (Ni-Mo impregnation solution): Weigh 13.5g nickel nitrate (Ni(NO3)2·6H2O) and 20.2g ammonium orthomolybdate ((NH4)6Mo7O 24 ·4H2O) were added sequentially to 100 mL of deionized water. The stirring temperature was controlled at 60°C and stirred at a constant speed for 30 minutes until completely dissolved to form a uniform transparent solution. The pH was adjusted to 3.5. This solution was reserved as the impregnation solution.

[0024] (3) Active metal loading (equal volume impregnation method): 80 g of calcined γ-Al2O3 powder was placed in a vacuum dryer and evacuated for 10 minutes to remove pore air. Then, it was slowly added to the above-mentioned Ni-Mo impregnation solution. The temperature was controlled at 40°C and an equal volume impregnation adsorption treatment was performed. After standing for 4 hours, it was dried under vacuum for 4 hours.

[0025] (4) Additive introduction and functional modification: Weigh 2.0 g of sodium dodecylbenzenesulfonate (SDBS) and dissolve it in 30 mL of ethanol. After ultrasonic treatment for 10 minutes, slowly add it dropwise to the above impregnation system as a dispersant modifier to enhance the uniformity of the metal distribution on the support surface. Continue stirring for 1 hour and allow to age for 6 hours.

[0026] (5) Drying and calcination: The impregnated wet catalyst was placed in a forced air drying oven, dried at 110°C for 12 hours, taken out, crushed and sieved, and then placed in a muffle furnace and calcined under a nitrogen atmosphere at gradually increasing temperature. The calcination procedure was as follows: the room temperature was raised to 300°C and maintained for 2 hours, then raised to 600°C and maintained for 4 hours, and finally slowly cooled to room temperature to obtain a Ni-Mo / γ-Al2O3 composite catalyst.

[0027] Example 2: (1) Preparation method of composite carrier ZrO2-SiO2: Weigh 30g of zirconium aluminate (ZrOCl2·8H2O) and 20g of ethyl orthosilicate, dissolve them in 200mL of anhydrous ethanol and 100mL of distilled water respectively, slowly mix the two solutions, stir for 2 hours, adjust the pH to 8.5, add appropriate amount of ammonia water to form a colloid, age for 24 hours, dry at 110℃ for 12 hours, and then calcine at 650℃ for 5 hours to obtain composite carrier ZrO2-SiO2.

[0028] (2) Preparation method of active metal impregnation solution: Weigh 12.0g nickel nitrate (Ni(NO3)2·6H2O) and 22.0g ammonium tungstate ((NH4) 10 W 12 O 41 5H2O) was dissolved in 120 mL of deionized water and stirred at constant temperature for 45 minutes until it was completely dissolved to form a Ni-W composite metal impregnation solution.

[0029] (3) Metal loading and additive introduction: Take 70g of the calcined ZrO2-SiO2 carrier, add the Ni-W impregnation solution using the equal volume impregnation method, let it stand for 3 hours, then add 5g of dispersant sodium carboxymethyl cellulose (CMC) dropwise, continue stirring for 1 hour, and let it stand for aging for 6 hours.

[0030] (4) Drying and roasting: The impregnated sample was placed in a forced air drying oven, dried at 105°C for 10 hours, taken out and crushed, and then calcined at 500°C for 4 hours under a nitrogen atmosphere to obtain a Ni-W / ZrO2-SiO2 natural gas catalyst.

[0031] Example 3: (1) Preparation method of composite carrier SiO2-Al2O3: Mix 20g of silica sol with 40g of aluminum sol, add 0.5g of surfactant hexadecyltrimethylammonium bromide, stir evenly, control the temperature to dry at 80℃ for 8 hours, grind, and calcine at 550℃ for 6 hours to obtain a SiO2-Al2O3 composite carrier with a high specific surface area.

[0032] (2) Preparation of active metal impregnation solution: Weigh 9.5 g of cobalt acetate (Co(CH3COO)2·4H2O) and 17.8 g of ammonium orthomolybdate, add them to 150 mL of deionized water, and stir for 30 minutes to form a transparent impregnation solution.

[0033] (3) Metal impregnation step: Weigh 60 g of the carrier and immerse it completely in the above solution using the equal volume impregnation method. After standing for 4 hours, add 2 g of non-ionic surfactant Tween 80 to improve the uniformity of metal distribution and stir for 1 hour.

[0034] (4) Drying and calcination: The drying process was carried out at a constant temperature of 110 °C for 12 hours, and then the temperature was raised to 600 °C at 5 °C per minute under nitrogen protection. After calcination for 4 hours, the mixture was naturally cooled to obtain a Co-Mo / SiO2-Al2O3 natural gas catalyst.

[0035] Example 4: (1) Preparation of composite oxide precursor: 15 g of cerium nitrate (Ce(NO3)3·6H2O) and 10 g of zirconium nitrate (ZrO(NO3)2·xH2O) were dissolved in 150 mL of water, and then 0.2 mol·L -1 Ammonia water was added to pH = 9 to form a precipitate, which was then aged for 12 hours, centrifuged, washed and dried, and calcined at 550 ° C for 5 hours to obtain Ce-Zr composite oxide.

[0036] (2) Loading onto the carrier: The obtained Ce-Zr oxide was mixed with 40 g of activated alumina powder in a ratio of 1:1, and a small amount of water and 2 g of polyvinyl alcohol were added as a binder. After ball milling for 2 hours, granulation was performed and dried to form a shape.

[0037] (3) Calcination treatment: The dried sample was calcined at 650℃ for 6 hours to prepare a Ce-Zr / Al2O3 composite support type natural gas hydrocracking catalyst.

[0038] Example 5: (1) Synthesis method of SAPO-11 molecular sieve carrier: Silica sol, aluminum metaphosphate and triisopropanolamine were mixed in a molar ratio of Al2O3:P2O5:SiO2:TIPA:H2O=1:1:0.3:1.3:70, stirred for 24 hours, transferred to a hydrothermal reactor, and crystallized at 180°C for 72 hours. The obtained crystals were washed and dried, and then calcined at 550°C for 6 hours to obtain SAPO-11 molecular sieve powder.

[0039] (2) Preparation method of precious metal impregnation solution: Weigh 0.25 g of chloroplatinic acid (H2PtCl6·6H2O) and 0.15 g of palladium chloride (PdCl2) respectively, dissolve them in 60 mL of deionized water and ultrasonically disperse them for 20 minutes.

[0040] (3) Impregnation and auxiliary treatment: 30 g of SAPO-11 carrier was added to the precious metal impregnation solution. After equal volume adsorption, 1 g of citric acid was added as a complex stabilizer, stirred for 2 hours, and allowed to stand for aging for 8 hours.

[0041] (4) Drying and roasting: The mixture was dried at 100°C for 12 hours and then reduced and calcined at 450°C for 3 hours in a hydrogen atmosphere to obtain a Pt-Pd / SAPO-11 bimetallic catalyst.

[0042] Performance Testing Catalytic Activity Test of Heavy Crude Oil Hydrodemetallization The catalysts of Examples 1-5 were respectively loaded into five parallel fixed-bed reactors; simulated natural gas (containing hydrogen) and heavy crude oil feedstock were introduced, heavy crude oil with high metal content (Ni+V>100ppm), the volume ratio of natural gas to feedstock volume was 1:1, the hydrogen concentration was 85% by volume (in natural gas), the reaction temperature was 410°C, the reaction pressure was 8 MPa, and the liquid hourly space velocity was 1.0 h -1 The catalyst loading was 50 mL, the reaction time was 12 hours, and liquid product samples were collected every 2 hours for analysis. The following table shows the test results:

[0043] Catalyst anti-carbon deposition and life test The catalyst was loaded into a microreactor; the reaction was carried out with continuous feeding and natural gas participation. The feed oil was residual oil or atmospheric residue oil, the natural gas flow rate was 300 mL / min (containing 90% hydrogen), the reaction temperature was 430°C, the reaction pressure was 6 MPa, the catalyst loading was 20 g, and the continuous operation time was 120 hours (5 days). The coke deposition and catalytic performance changes were analyzed every 24 hours. After the reaction, the coke content was detected using a thermogravimetric analyzer (TGA). The test results are shown in the following table:

[0044] The above shows and describes the basic principles, main features and advantages of the present invention; those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected; the scope of protection claimed in the present invention is defined by the attached claims and their equivalents.

Claims

1. A catalyst for catalyzing the refining of heavy crude oil using natural gas, characterized by: The following components are weighed according to the formula, in percentage by weight: 2-6% nickel-rhenium bimetallic nanoclusters, 3-7% molybdenum-cerium-boron ternary co-catalyst, 2-5% titanium nitride or lanthanum oxide plasma response component, 30-45% silica-alumina-zirconium oxide ternary composite carrier, 10-20% silicoaluminophosphate molecular sieve shell, and the rest is solvent or diluent.

2. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The preparation method of the nickel-rhenium bimetallic nanoclusters includes: dissolving nickel nitrate and rhenium trichloride in deionized water at a mass ratio of 3:1, loading them onto a carrier using an impregnation-reduction method, reducing them at 400 degrees Celsius for 4 to 6 hours in a hydrogen atmosphere, cooling them to room temperature, centrifuging and drying them to obtain nickel-rhenium nanoclusters with a particle size of 2 to 5 nanometers.

3. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The preparation method of the molybdenum-cerium-boron ternary promoter comprises: dissolving a molybdenum source, a cerium source and a boron source in deionized water at a molar ratio of 1:1:0.2 to form a uniform sol, slowly adding the sol to a carrier system, and performing stirring, hydrothermal treatment, drying and calcining to obtain the catalyst.

4. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The preparation method of the plasma-responsive component includes: doping titanium nitride or lanthanum oxide into a carrier system at a ratio of 2-5% by mass, uniformly mixing, and then calcining at 500 to 600 degrees Celsius for 3 to 5 hours to enhance its surface excitation response capability.

5. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The preparation method of the silica-alumina-zirconium oxide composite carrier includes: adding silica sol, aluminum nitrate and zirconium oxychloride in a molar ratio of 1:1:0.5 to deionized water, adjusting the pH value to 8.5 to 9.0, performing a hydrothermal reaction at 120 to 150 degrees Celsius for 12 hours after ultrasonic dispersion, and drying and calcining the obtained precursor to obtain a ternary composite carrier with a mesoporous structure.

6. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The coating method of the silicoaluminophosphate molecular sieve shell layer includes: placing the composite catalytic material in a silicoaluminophosphate molecular sieve synthesis solution, crystallizing at 150 to 180 degrees Celsius for 12 to 24 hours, filtering and washing, and calcining at 550 degrees Celsius to form a molecular sieve shell layer with a thickness of 10 to 50 nanometers.

7. The catalyst for catalyzing heavy crude oil refining using natural gas according to claim 1, characterized in that: The solvent is ethanol or isopropanol, which is used to dissolve the catalytic components and is subjected to ultrasonic treatment for 20 to 40 minutes to form a nano-uniform dispersion system.

8. A process for preparing a catalyst for catalyzing heavy crude oil refining using natural gas, characterized in that: The steps include: S1, preparing a silica-alumina-zirconia ternary composite support; S2, sequentially loading nickel-rhenium bimetallic clusters, molybdenum-cerium-boron ternary co-catalysts, and titanium nitride or lanthanum oxide response components; S3, constructing a silicoaluminophosphate molecular sieve shell layer on its surface by a hydrothermal coating method; S4. The obtained material is subjected to ultrasonic dispersion, high-temperature calcination and drying under inert gas protection to obtain the target catalyst.

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