Titanium composite catalyst and preparation method and application thereof

Abstract

The invention discloses a titanium composite catalyst and a preparation method and application thereof, and belongs to the technical field of composite catalysts.The preparation method comprises the steps that a catalyst carrier and a crucible containing melamine are transferred into a muffle furnace to be heated, a semi-finished product catalyst loaded with carbon nitride nanosheets is obtained, titanyl sulfate and deionized water are added into a reaction kettle to be stirred and dissolved, and the titanium composite catalyst is obtained; adding absolute ethyl alcohol and a semi-finished product catalyst, carrying out vacuum impregnation after ultrasonic dispersion, dropwise adding ammonia water, and carrying out a heat preservation reaction to obtain a titanium composite catalyst; carbon nitride has excellent electron conduction performance and chemical stability, and can promote cracking and conversion of heavy oil molecules; metatitanic acid provides more acidic sites and catalytic activity centers, and is helpful for accelerating the cracking reaction of heavy oil molecules; the catalyst carrier is used as a support and a dispersant of the active components, and the combination of the three can significantly improve the conversion rate of heavy oil catalytic cracking and improve the quality and yield of catalytic cracking products.

Description

Technical Field

[0001] The invention belongs to the technical field of composite catalysts, and specifically relates to a titanium composite catalyst and a preparation method and application thereof. Background Art

[0002] More than 70% of my country's commercial gasoline raw materials come from catalytic cracking gasoline. As the core process of petroleum processing, catalytic cracking has an important impact on the supply of light oil raw materials to the downstream chemical industry chain. With the advancement of technology and the heavy quality of crude oil, the application scope of catalytic cracking raw materials has gradually expanded, from diesel fractions and vacuum distillates to deasphalted, coking distillates, viscous cracking heavy oil, shale oil, coal tar and even atmospheric residue or vacuum residue, etc. The processing of heavy crude oil is still a key research direction.

[0003] In recent years, the catalytic cracking process will pay more attention to the characteristics of components with different structures in process research and development, select hard-to-crack components for modification, and form a combined processing route. For example, in-depth research on the molecular structure of heavy oil products, based on the structural characteristics, form a combined process technology; continue to study the effects of different bio-oil mixed feeds, select components with too high oxygen content for modification, and form a biological raw material processing route.

[0004] In terms of catalyst research and development, more personalized needs are reflected. Through the development of advanced matrix and catalytic materials, the effective combination of mesoporous molecular sieves and medium- and macroporous matrix, combined with heavy metal capture technology, the goal of reducing the yield of coke, dry gas, and oil slurry and increasing high-added products such as gasoline, diesel, and low-carbon olefins is achieved. In the existing technology, the conversion rate of heavy oil is generally less than 80%. How to improve the catalyst and increase the conversion rate of heavy oil is one of the focuses of industrial research. Summary of the invention

[0005] The purpose of the present invention is to provide a titanium composite catalyst and a preparation method and application thereof. The titanium composite catalyst is prepared by loading carbon nitride and metatitanic acid on a catalyst carrier, which helps to improve the conversion rate of heavy oil in heavy oil cracking catalysis.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for preparing a titanium composite catalyst comprises the following steps:

[0008] Step 1: Add ammonium fluoride, nickel nitrate hexahydrate and deionized water to a reactor, stir and mix, then add urea, stir at 200-300r / min for 10-20min, then add pretreated nickel foam particles to the reactor, stir and react at 130-140°C for 8-10h, cool naturally, filter, wash the product particles with deionized water 2-3 times, vacuum dry, and then transfer to a muffle furnace, calcine at 480-500°C for 1.5-2h to obtain roughened nickel foam particles.

[0009] Step 2: Under stirring conditions of 35°C and 200-300r / min, potassium hydroxide, deionized water and 1,6-hexanediamine are added to the reactor, sodium aluminate is added after stirring for 5-10min, fumed silica is added after stirring for 20-30min, stirring is continued for 20-30min, roughened nickel foam particles and ZSM-5 nano zeolite as a seed are added to the reactor, the mixed solution is transferred to a crystallization kettle after stirring for 3-3.5h, pre-crystallized at 100-105°C and 300-500r / min for 24h, crystallized at 160-165°C for 48h, the crystallized product is filtered out, transferred to a muffle furnace, kept warm at 600°C for 10-12h, cooled naturally, the particles are ultrasonically cleaned with deionized water for 5-10min, and vacuum dried to obtain a catalyst carrier.

[0010] Step 3: Transfer the catalyst carrier and the crucible containing melamine to a muffle furnace, and under argon protection, heat to 320-350°C at a rate of 4-5°C / min, keep warm for 10-12 hours, cool naturally, take out the particles, ultrasonically clean them with anhydrous ethanol for 5-10 minutes, and vacuum dry them to obtain a semi-finished catalyst loaded with carbon nitride nanosheets.

[0011] Step 4: Add titanium oxysulfate and deionized water into the reactor and stir to dissolve, then add anhydrous ethanol and semi-finished catalyst into the reactor, ultrasonically disperse for 15-20 minutes, and vacuum impregnate for 2-3 hours to make TiO 2+ The titanium composite catalyst is fully adsorbed into the pores on the surface of the semi-finished catalyst, and then 25% ammonia water is added to the reactor, reacted at 140-150°C for 10-12 hours, naturally cooled, filtered, and the particles are washed with deionized water and anhydrous ethanol for 3-5 times respectively, and vacuum dried to obtain a titanium composite catalyst, thereby completing the preparation method of the titanium composite catalyst.

[0012] Further, the pretreated nickel foam particles are prepared by the following steps:

[0013] The nickel foam particles with a particle size of 0.3-0.5 cm were ultrasonically cleaned for 5-10 minutes with a hydrochloric acid solution with a molar concentration of 3 mol / L to remove the oxide film on the surface, and then washed with deionized water until the last washing solution was neutral, and dried to obtain pretreated nickel foam particles.

[0014] Furthermore, the usage ratio of ammonium fluoride, nickel nitrate hexahydrate, deionized water, urea and pretreated nickel foam particles is 0.24-0.25 g: 5.8-6 g: 50 mL: 0.48-0.5 g: 5 g.

[0015] Furthermore, the mass ratio of potassium hydroxide, deionized water, 1,6-hexanediamine, sodium aluminate, fumed silica, roughened nickel foam particles and ZSM-5 nano zeolite is 5:800:14.5-15:0.55-0.6:60:60:15.

[0016] Furthermore, the mass ratio of the catalyst carrier to melamine is 4-5:1.

[0017] Furthermore, the dosage ratio of titanyl sulfate, deionized water, anhydrous ethanol, semi-finished catalyst and ammonia water is 10g:55mL:15-25mL:5g:0.05-0.06mL.

[0018] The titanium composite catalyst can be applied to the catalytic cracking of heavy oil.

[0019] Beneficial effects of the present invention:

[0020] The titanium composite catalyst of the present invention exhibits better heavy oil catalytic cracking ability and is helpful to improve the conversion rate of raw oil.

[0021] During the preparation process of the titanium composite catalyst, nano-nickel oxide is deposited on the surface of the pretreated nickel foam particles. The nano-nickel oxide presents a flaky structure, which makes the surface of the roughened nickel foam have more unevenness and pore structure. This structure provides more attachment points and a larger contact area for the subsequent nano-zeolite, promotes the uniform distribution and firm bonding of the nano-zeolite thereon, thereby preparing a catalyst carrier with a larger specific surface area, which helps to load more nano-carbon nitride.

[0022] The nano-zeolite on the surface of the catalyst carrier is seeded with ZSM-5 nano-zeolite, so it presents a hollow structure, which helps to adsorb more TiO 2+ , and then hydrolyze to generate tiny metatitanic acid crystal nuclei and fix them in the hollow structure, which helps to improve the stability and activity of the titanium composite catalyst.

[0023] Carbon nitride has excellent electronic conductivity and chemical stability, and can promote the cracking and conversion of heavy oil molecules. Metatitanic acid provides more acid sites and catalytic active centers, which helps to accelerate the cracking reaction of heavy oil molecules. The catalyst carrier serves as a support and dispersant for these active components, ensuring their uniform distribution and efficient utilization during the reaction. Therefore, the combination of these three can significantly improve the conversion rate of heavy oil catalytic cracking and improve the quality and yield of catalytic cracking products. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1: This example provides a titanium composite catalyst, which is prepared by the following method:

[0026] S1: The nickel foam particles with a particle size of 0.3 cm were ultrasonically cleaned for 5 minutes with a hydrochloric acid solution with a molar concentration of 3 mol / L to remove the oxide film on the surface, and then washed with deionized water until the last washing solution was neutral, and dried to obtain pretreated nickel foam particles.

[0027] S2: Add 240g of ammonium fluoride, 5.8kg of nickel nitrate hexahydrate and 50L of deionized water into the reactor, stir and mix, then add 480g of urea, stir at 200r / min for 10min, then add 5kg of pretreated foam nickel particles into the reactor, stir and react at 130°C for 8h, cool naturally, filter, wash the product particles with deionized water twice, vacuum dry, and then transfer to a muffle furnace, calcine at 480°C for 1.5h to obtain roughened foam nickel particles.

[0028] S3: Under stirring conditions of 35°C and 200r / min, 50g of potassium hydroxide, 8kg of deionized water and 145g of 1,6-hexanediamine were added to the reactor, 5.5g of sodium aluminate was added after stirring for 5min, 600g of fumed silica was added after stirring for 20min, and stirring was continued for 20min. Then, 600g of roughened nickel foam particles and 150g of ZSM-5 nano zeolite as a seed were added to the reactor. After stirring for 3h, the mixed solution was transferred to a crystallization kettle, pre-crystallized at 100°C and 300r / min for 24h, and crystallized at 160°C for 48h. The crystallized product was filtered out and transferred to a muffle furnace, kept warm at 600°C for 10h, cooled naturally, and the particles were ultrasonically cleaned with deionized water for 5min and vacuum dried to obtain a catalyst carrier.

[0029] S4: 400 g of the catalyst carrier and a crucible containing 100 g of melamine were transferred to a muffle furnace. Under argon protection, the temperature was raised to 320°C at a rate of 4°C / min, kept warm for 10 hours, and cooled naturally. After the particles were taken out, they were ultrasonically cleaned with anhydrous ethanol for 5 minutes and vacuum dried to obtain a semi-finished catalyst loaded with carbon nitride nanosheets.

[0030] S5: 100g of titanium oxysulfate and 550mL of deionized water were added to the reactor and stirred to dissolve. Then 150mL of anhydrous ethanol and 50g of the semi-finished catalyst were added to the reactor, ultrasonically dispersed for 15min, and vacuum impregnated for 2h to make TiO 2+ It is fully adsorbed into the pores on the surface of the semi-finished catalyst, and then 0.5 mL of 25% ammonia water is added to the reactor, reacted at 140°C for 10 hours, naturally cooled, filtered, and the particles are washed three times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain a titanium composite catalyst.

[0031] Example 2: This example provides a titanium composite catalyst, which is prepared by the following method:

[0032] S1: The nickel foam particles with a particle size of 0.4 cm were ultrasonically cleaned for 8 minutes with a hydrochloric acid solution with a molar concentration of 3 mol / L to remove the oxide film on the surface, and then washed with deionized water until the last washing solution was neutral, and dried to obtain pretreated nickel foam particles.

[0033] S2: Add 245g of ammonium fluoride, 5.9kg of nickel nitrate hexahydrate and 50L of deionized water into the reactor, stir and mix, then add 490g of urea, stir at 250r / min for 15min, then add 5kg of pretreated foam nickel particles into the reactor, stir and react at 135°C for 9h, cool naturally, filter, wash the product particles with deionized water twice, vacuum dry, and then transfer to a muffle furnace, calcine at 490°C for 1.8h to obtain roughened foam nickel particles.

[0034] S3: Under stirring conditions of 35°C and 250r / min, 50g of potassium hydroxide, 8kg of deionized water and 148g of 1,6-hexanediamine were added to the reactor, 5.8g of sodium aluminate was added after stirring for 8min, 600g of fumed silica was added after stirring for 25min, and stirring was continued for 25min. Then, 600g of roughened nickel foam particles and 150g of ZSM-5 nano zeolite as a seed were added to the reactor, and after stirring for 3.2h, the mixed solution was transferred to a crystallization kettle, pre-crystallized at 102°C and 400r / min for 24h, and crystallized at 162°C for 48h. The crystallized product was filtered out and transferred to a muffle furnace, kept warm at 600°C for 11h, cooled naturally, and the particles were ultrasonically cleaned with deionized water for 8min, and vacuum dried to obtain a catalyst carrier.

[0035] S4: 450 g of the catalyst carrier and a crucible containing 100 g of melamine were transferred to a muffle furnace. Under argon protection, the temperature was raised to 335°C at a rate of 4.5°C / min, kept warm for 11 hours, and cooled naturally. After the particles were taken out, they were ultrasonically cleaned with anhydrous ethanol for 8 minutes and vacuum dried to obtain a semi-finished catalyst loaded with carbon nitride nanosheets.

[0036] S5: 100 g of titanium oxysulfate and 550 mL of deionized water were added to the reactor and stirred to dissolve. Then 200 mL of anhydrous ethanol and 50 g of the semi-finished catalyst were added to the reactor, ultrasonically dispersed for 18 min, and vacuum impregnated for 2.5 h to make TiO 2+ It was fully adsorbed into the pores on the surface of the semi-finished catalyst, and then 0.55 mL of 25% ammonia water was added to the reactor, reacted at 145°C for 11 hours, cooled naturally, filtered, and the particles were washed 4 times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain a titanium composite catalyst.

[0037] Example 3: This example provides a titanium composite catalyst, which is prepared by the following method:

[0038] S1: The nickel foam particles with a particle size of 0.5 cm were ultrasonically cleaned with a hydrochloric acid solution with a molar concentration of 3 mol / L for 10 min to remove the oxide film on the surface, and then washed with deionized water until the last washing solution was neutral, and dried to obtain pretreated nickel foam particles.

[0039] S2: Add 250g of ammonium fluoride, 6kg of nickel nitrate hexahydrate and 50L of deionized water into the reactor, stir and mix, then add 500g of urea, stir at 300r / min for 20min, then add 5kg of pretreated foam nickel particles into the reactor, stir and react at 140°C for 10h, cool naturally, filter, wash the product particles with deionized water 3 times, vacuum dry, and then transfer to a muffle furnace, calcine at 500°C for 2h to obtain roughened foam nickel particles.

[0040] S3: Under stirring conditions of 35°C and 300r / min, 50g potassium hydroxide, 8kg deionized water and 150g 1,6-hexanediamine were added to the reactor, 6g sodium aluminate was added after stirring for 10min, 600g fumed silica was added after stirring for 30min, and stirring was continued for 30min. Then, 600g roughened nickel foam particles and 150g ZSM-5 nano zeolite as a seed were added to the reactor, and after stirring for 3.5h, the mixed solution was transferred to a crystallization kettle, pre-crystallized at 105°C and 500r / min for 24h, and crystallized at 165°C for 48h. The crystallized product was filtered out and transferred to a muffle furnace, kept warm at 600°C for 12h, cooled naturally, and the particles were ultrasonically cleaned with deionized water for 10min, and vacuum dried to obtain a catalyst carrier.

[0041] S4: 500 g of the catalyst carrier and a crucible containing 100 g of melamine were transferred to a muffle furnace. Under argon protection, the temperature was raised to 350°C at a rate of 5°C / min, kept warm for 12 hours, and cooled naturally. After the particles were taken out, they were ultrasonically cleaned with anhydrous ethanol for 10 minutes and vacuum dried to obtain a semi-finished catalyst loaded with carbon nitride nanosheets.

[0042] S5: 100g of titanium oxysulfate and 550mL of deionized water were added to the reactor and stirred to dissolve. Then 250mL of anhydrous ethanol and 50g of the semi-finished catalyst were added to the reactor, ultrasonically dispersed for 20min, and vacuum impregnated for 3h to make TiO 2+ It is fully adsorbed into the pores on the surface of the semi-finished catalyst, and then 0.6 mL of 25% ammonia water is added to the reactor, reacted at 150°C for 12 hours, naturally cooled, filtered, and the particles are washed 5 times with deionized water and anhydrous ethanol respectively, and vacuum dried to obtain a titanium composite catalyst.

[0043] In the embodiment, the pore size of the nickel foam particles is 0.5-2 mm, the porosity is 90-98%, and the through-porosity is ≥98%.

[0044] Comparative Example 1: Based on Example 3, without the treatment in step S2, step S3 directly replaces the roughened nickel foam particles with the pretreated nickel foam particles in step S1, and the other steps remain unchanged to prepare a titanium composite catalyst.

[0045] Comparative Example 2: Based on Example 3, without the treatment in step S3, step S4 directly replaces the catalyst carrier with the roughened nickel foam particles in step S2, and the other steps remain unchanged to prepare a titanium composite catalyst.

[0046] Comparative Example 3: Based on Example 3, without the treatment of step S4, step S5 directly replaces the semi-finished catalyst with the catalyst carrier in step S3, and the other steps remain unchanged to prepare a titanium composite catalyst.

[0047] Comparative Example 4: Based on Example 3, the semi-finished catalyst in step S4 is directly used without being processed in step S5.

[0048] Performance tests were performed on Examples 1 to 3 and Comparative Examples 1 to 3.

[0049] The properties of the crude oil are shown in Table 1:

[0050] Table 1 Raw oil properties

[0051]

[0052] The heavy oil catalytic cracking reaction performance of different catalysts was evaluated on an ACE catalytic cracking evaluation device (Kayser, USA). The temperature of the device was 520°C, the mass ratio of catalyst to feedstock oil was 7, and the ratios of the products after cracking were shown in Table 2:

[0053] Table 2 Catalytic cracking performance results of each catalyst

[0054]

[0055]

[0056] It can be seen from Table 2 that the titanium composite catalysts in Examples 1 to 3 exhibit better heavy oil catalytic cracking capabilities, which are helpful in improving the conversion rate of the feedstock oil.

[0057] The heavy oil catalytic cracking capacity in Comparative Examples 1 and 2 decreased, probably because nano nickel oxide was not deposited or nano zeolite was not loaded during the preparation of the titanium composite catalyst, resulting in a reduction in the final loaded catalytic substance. Comparative Examples 3 and 4 show that loading nano carbon nitride and loading metatitanic acid are both helpful in improving the catalytic cracking capacity of heavy oil.

[0058] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a titanium composite catalyst, characterized in that: The steps include: Step 1: Transfer the catalyst carrier and the crucible containing melamine to a muffle furnace, and under the protection of argon, heat to 320-350°C at a rate of 4-5°C / min, keep warm for 10-12 hours, cool naturally, take out the particles, ultrasonically clean them with anhydrous ethanol for 5-10 minutes, and vacuum dry them to obtain a semi-finished catalyst loaded with carbon nitride nanosheets; Step 2: Add titanium oxysulfate and deionized water into a reactor and stir to dissolve, then add anhydrous ethanol and a semi-finished catalyst into the reactor, ultrasonically disperse for 15-20 minutes, vacuum impregnate for 2-3 hours, then drop 25% ammonia water into the reactor, react at 140-150° C. for 10-12 hours, cool naturally, filter, wash the particles with deionized water and anhydrous ethanol for 3-5 times respectively, and vacuum dry to obtain a titanium composite catalyst, thereby completing the preparation method of the titanium composite catalyst.

2. The method for preparing a titanium composite catalyst according to claim 1, characterized in that: The mass ratio of the catalyst carrier to melamine is 4-5:

1.

3. The method for preparing a titanium composite catalyst according to claim 1, characterized in that: The dosage ratio of the titanyl sulfate, deionized water, anhydrous ethanol, semi-finished catalyst and ammonia water is 10g:55mL:15-25mL:5g:0.05-0.06mL.

4. The method for preparing a titanium composite catalyst according to claim 1, characterized in that: The catalyst support is prepared by the following steps: Under stirring conditions of 35° C. and 200-300 r / min, potassium hydroxide, deionized water and 1,6-hexanediamine are added to the reactor, sodium aluminate is added after stirring for 5-10 minutes, fumed silica is added after stirring for 20-30 minutes, stirring is continued for 20-30 minutes, roughened nickel foam particles and ZSM-5 nano zeolite as a seed are added to the reactor, the mixed solution is transferred to a crystallization kettle after stirring for 3-3.5 hours, pre-crystallized at 100-105° C. and 300-500 r / min for 24 hours, crystallized at 160-165° C. for 48 hours, the crystallized product is filtered out, transferred to a muffle furnace, kept warm at 600° C. for 10-12 hours, cooled naturally, the particles are ultrasonically cleaned with deionized water for 5-10 minutes, and vacuum dried to obtain a catalyst carrier.

5. The method for preparing a titanium composite catalyst according to claim 4, characterized in that: The mass ratio of potassium hydroxide, deionized water, 1,6-hexanediamine, sodium aluminate, fumed silica, roughened nickel foam particles and ZSM-5 nano zeolite is 5:800:14.5-15:0.55-0.6:60:60:

15.

6. The method for preparing a titanium composite catalyst according to claim 4, characterized in that: The roughened nickel foam particles are prepared by the following steps: Add ammonium fluoride, nickel nitrate hexahydrate and deionized water to the reactor, stir and mix, then add urea, stir at 200-300r / min for 10-20min, then add pretreated nickel foam particles to the reactor, stir and react at 130-140°C for 8-10h, cool naturally, filter, wash the product particles with deionized water 2-3 times, vacuum dry, then transfer to a muffle furnace, and calcine at 480-500°C for 1.5-2h to obtain roughened nickel foam particles.

7. The method for preparing a titanium composite catalyst according to claim 6, characterized in that: The usage ratio of the ammonium fluoride, nickel nitrate hexahydrate, deionized water, urea and pretreated nickel foam particles is 0.24-0.25 g: 5.8-6 g: 50 mL: 0.48-0.5 g: 5 g.

8. The method for preparing a titanium composite catalyst according to claim 6, characterized in that: The pretreated nickel foam particles are prepared by the following steps: The nickel foam particles with a particle size of 0.3-0.5 cm were ultrasonically cleaned with a hydrochloric acid solution with a molar concentration of 3 mol / L for 5-10 minutes to remove the oxide film on the surface, and then washed with deionized water until the last washing solution was neutral, and dried to obtain pretreated nickel foam particles.

9. A titanium composite catalyst, characterized in that The catalyst is prepared by the method for preparing a titanium composite catalyst according to any one of claims 1 to 8.

10. Use of the titanium composite catalyst according to claim 9 in heavy oil cracking catalysis.

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