Isomerization pour point depressing catalyst as well as preparation method and application thereof
By soaking the carrier in carbon residue introduction agent and partially oxidizing the carrier, the distribution of active components is finely controlled, which solves the problem of low selectivity of long linear hydrocarbon isomerization reaction in Fischer-Tropsch synthesis distillate, and improves the isomer and Base oil yield.
Patent Information
- Application Number
- CN202411406739.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-01-24
AI Technical Summary
The medium- and long linear hydrocarbon isomerization reaction of Fischer-Tropsch synthetic distillate oil is not selective, and the operation and process of introducing carbon deposits in the patent CN115672388A is difficult to operate and complicated.
By soaking the carbon introduction agent in the carrier-partial oxidation, limit the load point of the subsequent active component, realize the fine control of the distribution of the active component.
The revenue of the heterogeneous body is increased, and the liquid revenue and basic oil revenue of the heterogeneity of wide distillation tail oil are increased, especially the high -grade base oil revenue.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of isomerized pour point depressing catalysts, and in particular relates to isomerized pour point depressing catalysts and a preparation method and application thereof. Background Art
[0002] With the development of environmental protection and mechanical industry, more stringent requirements are put forward for the quality of lubricant products. Lubricants should have high antioxidant stability, better viscosity-temperature properties, better low-temperature fluidity, and excellent shear stability and anti-wear properties. Since the method of improving the performance of lubricants by adjusting the additive formula alone can no longer meet the relevant requirements, higher requirements are put forward for the quality of lubricant base oils. In addition, the quality of mineral lubricants produced by traditional processes is difficult to further improve. At the same time, the crude oil resources suitable for lubricant production are decreasing worldwide. Therefore, lubricant production must face inferior heavy crude oil, which is also a problem for traditional processing technology.
[0003] With the development of coal chemical industry, all products obtained through Fischer-Tropsch synthesis contain no or low sulfur, nitrogen and aromatics, are colorless, odorless, and burn cleanly. They are not only good clean fuels, but also good petrochemical raw materials and special chemicals. The Fischer-Tropsch synthesis products are fractionated, and the separated base oil precursor fractions are subjected to catalytic dewaxing process to produce base oils of different grades; the separated heavy fraction oils are subjected to hydrogenation isomerization and catalyst dewaxing process to produce base oils of different grades. The lubricating oil base oil produced from the Fischer-Tropsch synthesis products does not contain sulfur, has a high viscosity index, and is highly biodegradable. It is very suitable for the preparation of a new generation of engine oils, can replace part of PAO, and prepare high-end lubricating oils and grease products. The Fischer-Tropsch synthesis process provides diversity for the source of lubricating oil base oil raw materials.
[0004] Considering the characteristics of Fischer-Tropsch synthesis products, converting them into lubricating oil base oils through isomerization decondensation has good development prospects, and the development of catalysts with higher isomerization reaction selectivity is particularly critical.
[0005] CN115672388A discloses a shape-selective isomerization catalyst and its preparation method and application. The invention treats a molecular sieve containing a template in an ozone atmosphere at 60-180°C to partially oxidize the template to form carbon deposits that fill the micropores of the aluminum silicate molecular sieve to obtain a carrier; by controlling the atmosphere and temperature of the molecular sieve carrier for oxidation demolding, the molecular sieve pore depth and acidity are effectively regulated, thereby improving the catalyst's activity and isomer yield for the isomerization reaction of long-chain normal alkanes.
[0006] In the actual production process, only by preparing from scratch can the original molecular sieve powder containing the template be obtained. The above-mentioned patent CN115672388A cannot use the conventional commercially available calcined molecular sieve raw materials; the usage and dosage of the template as the carbon source of carbon deposition in the carrier pores are closely related to the type of synthesized molecular sieve, and the dosage of the template cannot be easily adjusted; the carbon deposition process needs to be processed under an ozone atmosphere, which puts higher requirements on raw materials and equipment, and the preparation process is relatively complicated. Summary of the invention
[0007] In order to solve the problems of low selectivity of isomerization reaction of long straight-chain hydrocarbons in Fischer-Tropsch synthesis distillate oil, and difficult and complicated process of carrier introduction of carbon deposition in patent CN115672388A, the present invention provides an isomerization decondensation catalyst and a preparation method and application thereof, which realizes fine regulation of the distribution of active components by soaking and partially oxidizing the carrier with a residual carbon introduction agent and limiting the subsequent loading points of active components; for the isomerization decondensation reaction of wide-fraction tail oil, the liquid yield of the product is increased, the base oil yield is increased, especially the yield of high-grade base oil.
[0008] The purpose of the present invention can be achieved by the following technical solutions:
[0009] According to one aspect of the present invention, there is provided a heterogeneous degassing catalyst, comprising an active component of a Group VIII noble metal and a modified composite molecular sieve carrier composed of a silicoaluminophosphate molecular sieve, a silica-alumino molecular sieve and a binder, wherein the active component is loaded on the modified composite molecular sieve carrier, and residual carbon is introduced into the micropores of the modified composite molecular sieve carrier by immersing a residual carbon introducing agent and performing a partial oxidation treatment, wherein the content of the residual carbon is 0.5 to 8.0% of the weight of the catalyst.
[0010] As a preferred technical solution, the mass percentage of each component in the catalyst is as follows:
[0011] 0.05-1.0% of Group VIII noble metal, 50-80% of silicoaluminophosphate molecular sieve, 10-30% of silica-alumino molecular sieve, 5-30% of binder and 0.5-8.0% of residual carbon.
[0012] As a preferred technical solution, the mass percentage of each component in the catalyst is as follows:
[0013] 0.1-0.3% of Group VIII noble metal, 60-80% of silicoaluminophosphate molecular sieve, 15-30% of silica-alumino molecular sieve, 10-30% of binder and 1.0-6.0% of residual carbon; preferably, 65-80% of silicoaluminophosphate molecular sieve, 15-25% of silica-alumino molecular sieve and 15-30% of binder;
[0014] And / or, the Group VIII noble metal is at least one of Pt, Pd, and Ru, the silicoaluminophosphate molecular sieve is one or more of SAPO-11, SAPO-31, and SAPO-41, the silicoalumino molecular sieve is one or more of ZSM-5, ZSM-22, β-molecular sieve, and SBA-15, and the binder is at least one of aluminum sol, pseudo-boehmite, and silica sol; preferably, the Group VIII noble metal is Pt or Pd, the silicoaluminophosphate molecular sieve is SAPO-11, the silicoalumino molecular sieve is β-molecular sieve, and the binder is pseudo-boehmite.
[0015] According to another aspect of the present invention, there is further provided a method for preparing an isomeric pour point depressant catalyst, comprising the following steps:
[0016] S1. After mixing the silicoaluminophosphate molecular sieve and the silica-alumino molecular sieve, adding the mixture into an acid solution for modification treatment, followed by filtering, washing, drying and calcining in sequence to obtain an acid-treated mixed molecular sieve;
[0017] S2, uniformly kneading the acid-treated mixed molecular sieve with a binder and a molding acid, and then sequentially molding, drying, calcining, crushing and screening to obtain a molded modified composite molecular sieve;
[0018] S3, soaking the above-formed modified composite molecular sieve in a residual carbon introducing agent, filtering after soaking, and then treating at 300-500° C. in an air environment, and through a partial oxidation treatment with rapid heating and a short time, the residual carbon introducing agent is incompletely oxidized in the catalyst pores to form residual carbon filled in the micropores of the carrier, thereby obtaining a carrier with introduced residual carbon;
[0019] S4, preparing a salt solution of Group VIII noble metals, and immersing the above-mentioned carrier introduced with residual carbon in the salt solution. After the active metal is loaded through immersion, the final catalyst is obtained.
[0020] The aluminum silicate molecular sieve raw powder of the present invention can be synthesized by a conventional hydrothermal method or a solvent thermal method, and the present invention does not particularly limit the preparation method of the aluminum silicate molecular sieve raw powder.
[0021] As a preferred technical solution, in step S3,
[0022] The residual carbon introducing agent comprises a diluent and a carbon source, wherein the diluent is at least one of C6-C8 normal alkanes with a mass fraction of 20-80%, and the carbon source is at least one of C12-C16 normal alkanes with a mass fraction of 20-80%.
[0023] As a preferred technical solution, in step S3,
[0024] The conditions for the partial oxidation treatment with rapid temperature increase and short time are controlled as follows:
[0025] Within 1 to 2 hours, the temperature is raised to a treatment temperature of 300 to 500°C and maintained for 1 to 2 hours.
[0026] As a preferred technical solution, in step S4,
[0027] The salt solution of the Group VIII noble metal is selected from at least one of chloroplatinic acid, chloropalladic acid, ruthenium trichloride, dichlorotetraammineplatinum, and dichlorotetraamminepalladium.
[0028] According to another aspect of the present invention, there is further provided an application of an isomerized pour point depressant catalyst.
[0029] The catalyst catalyzes the isomerization and decondensation reaction of long straight-chain hydrocarbons in the Fischer-Tropsch synthesis fraction oil, thereby preparing the lubricating oil base oil.
[0030] The present invention adopts the above technical solution to have at least the following beneficial effects:
[0031] Compared with the transparent microporous channel shape-selective isomerization catalyst, the method of the present invention shortens the channel depth and limits the distribution of the active component in the microporous channel by introducing residual carbon before loading the active component. This reduces the active sites inside the microporous channel, thereby avoiding the cracking reaction that occurs when long-chain alkanes enter the channel deeply. When the pore size is limited, straight-chain alkanes can only undergo cracking reactions, which reduces the cracking probability of long-chain hydrocarbons and thus increases the yield of isomers. For the isomerization decondensation reaction of wide-fraction tail oil, this method not only increases the liquid yield of the product, but also increases the yield of base oil, especially the yield of high-grade base oil;
[0032] Compared with the traditional technology of in-situ generation of carbon deposits through template oxidation and partial filling of molecular sieve micropores, the present invention improves the method of introducing residual carbon. By immersing the carrier in a residual carbon introducing agent and partially oxidizing it, the loading position of the subsequent active components is limited, thereby achieving fine control of the distribution of the active components. The advantage of the present invention is that there is no need to synthesize molecular sieve raw powder containing a template from scratch, but commercially available molecular sieves that have been calcined to remove the template can be used, and the source of raw materials is wider. In addition, by adjusting the formula of the residual carbon introducing agent, the amount of residual carbon introduced can be conveniently controlled to achieve the purpose of fine control. The present invention does not require partial oxidation treatment in an ozone environment, has lower requirements for raw materials and equipment, and is more convenient. DETAILED DESCRIPTION
[0033] The following is a detailed description of the embodiments of the present invention. The embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The experimental methods in the following embodiments where specific conditions are not specified are usually based on conventional conditions.
[0034] Comparative Example 1
[0035] 1) 50 g SAPO-11, 5 g SBA-15 molecular sieve and 10 g (by weight of dry alumina) pseudo-boehmite SB powder were mixed evenly, and then 10 mL 10 wt% dilute nitric acid was added and kneaded evenly, followed by tableting, drying, calcining, crushing and sieving to 20-40 mesh to obtain a formed molecular sieve carrier;
[0036] 2) Take 50g of the formed molecular sieve carrier, use H2PtCl6 as the platinum source, and impregnate 0.3% of the active metal Pt by volume, then dry and calcine to prepare the catalyst and record it as: Pt 0.3 / SAPO-11 / SBA-15.
[0037] Example 1
[0038] 1) 50 g SAPO-11, 5 g SBA-15 molecular sieve and 10 g (by weight of dry alumina) pseudo-boehmite SB powder were mixed evenly, and then 10 mL 10 wt% dilute nitric acid was added and kneaded evenly, followed by tableting, drying, calcining, crushing and sieving to 20-40 mesh to obtain a formed molecular sieve carrier;
[0039] 2) preparing a carbon introduction agent of 80% n-hexane / 20% n-hexadecane by mass, soaking the formed molecular sieve carrier at a liquid-solid ratio of 10:1, and soaking for 2 hours at room temperature; filtering after soaking, and using a muffle furnace to partially oxidize the carrier mixed with the carbon introduction agent to introduce carbon: in an air atmosphere, heating to 300° C. for 1 hour, and maintaining the temperature for 2 hours; the carbon introduction agent is partially oxidized to form carbon to fill the micropores of the carrier, and a carrier with carbon introduced is obtained;
[0040] 3) A molecular sieve carrier with 50 g of residual carbon introduced was taken, and H2PtCl6 was used as a platinum source, and an equal volume of active metal Pt with a mass fraction of 0.3% was impregnated to prepare a catalyst with a residual carbon content of 2.18%.
[0041] Comparative Example 2
[0042] 45g SAPO-41, 5g ZSM-22 and 10g β-molecular sieve were mixed and added to a 0.3mol / L acetic acid solution at 60°C and allowed to stand for 1.5h for modification treatment, with a liquid-to-solid ratio of 4:1; then filtered, washed, dried and calcined in sequence to obtain an acid-treated mixed molecular sieve;
[0043] 2) 50 g of the acid-treated mixed molecular sieve, 10 g of aluminum sol, and 10 mL of 8 wt% nitric acid solution were kneaded evenly, and then tableted, dried, and calcined in sequence, and then crushed and sieved to 20-40 mesh to obtain a shaped modified composite molecular sieve;
[0044] 3) Take 50g of the shaped modified composite molecular sieve, use RuCl3 as the ruthenium source, and impregnate 0.1% by mass of active metal Ru in equal volume, and then dry and calcine to prepare a catalyst.
[0045] Example 2
[0046] 45g SAPO-41, 5g ZSM-22 and 10g β-molecular sieve were mixed and added to a 0.3mol / L acetic acid solution at 60°C and allowed to stand for 1.5h for modification treatment, with a liquid-to-solid ratio of 4:1; then filtered, washed, dried and calcined in sequence to obtain an acid-treated mixed molecular sieve;
[0047] 2) 50 g of the acid-treated mixed molecular sieve, 10 g of aluminum sol, and 10 mL of 8 wt% nitric acid solution were kneaded evenly, and then tableted, dried, and calcined in sequence, and then crushed and sieved to 20-40 mesh to obtain a shaped modified composite molecular sieve;
[0048] 3) preparing a carbon residue introducing agent of 50% n-hexane / 50% n-dodecane by mass fraction, soaking the formed modified composite molecular sieve at a liquid-solid ratio of 10:1, and soaking for 2 hours at room temperature; filtering after soaking, and using a muffle furnace to partially oxidize the modified composite molecular sieve mixed with the carbon residue introducing agent to introduce carbon residue: in an air atmosphere, heating to 500° C. for 1 hour, and maintaining the temperature for 2 hours; the carbon residue introducing agent is partially oxidized to form carbon residue filling the micropores of the molecular sieve, and a carrier for introducing carbon residue is obtained;
[0049] 4) 50 g of the carrier with residual carbon introduced was taken, and RuCl3 was used as the ruthenium source, and an equal volume of active metal Ru was impregnated with 0.1% by mass, and then dried and calcined to prepare a catalyst with a residual carbon content of 0.53%.
[0050] Comparative Example 3
[0051] 1) 45 g SAPO-31 and 15 g ZSM-5 molecular sieve were mixed, and the mixed molecular sieve was treated with 160 mL 0.2 mol / L citric acid solution at 60° C. for 1.5 hours, and then filtered, washed, dried, and calcined in sequence to obtain an acid-treated mixed molecular sieve;
[0052] 2) Take 50g of acid-treated mixed molecular sieve and 10g of silica sol, add 12mL of 10wt% dilute nitric acid and knead evenly, then press into tablets, dry, calcine, crush and sieve to 20-40 mesh, to obtain a shaped modified composite molecular sieve;
[0053] 3) Take 40g of the shaped modified composite molecular sieve, use H2PdCl6 as a palladium source, impregnate an equal volume of 0.2% by mass of active metal Pd, and then dry and calcine to prepare a catalyst.
[0054] Example 3
[0055] 1) 45 g SAPO-31 and 15 g ZSM-5 molecular sieve were mixed, and the mixed molecular sieve was treated with 160 mL 0.2 mol / L citric acid solution at 60° C. for 1.5 hours, and then filtered, washed, dried, and calcined in sequence to obtain an acid-treated mixed molecular sieve;
[0056] 2) Take 50g of acid-treated mixed molecular sieve and 10g of silica sol, add 12mL of 10wt% dilute nitric acid and knead evenly, then press into tablets, dry, calcine, crush and sieve to 20-40 mesh, to obtain a shaped modified composite molecular sieve;
[0057] 3) preparing a carbon residue introduction agent of 20% n-octane / 80% n-hexadecane by mass, soaking the modified composite molecular sieve at a liquid-solid ratio of 10:1, and soaking for 2 hours at room temperature; filtering after soaking, and partially oxidizing the modified composite molecular sieve mixed with the carbon residue introduction agent using a muffle furnace to introduce carbon residue: in an air atmosphere, heating to 350° C. for 2 hours, and maintaining the temperature for 1 hour; the carbon residue introduction agent is partially oxidized to form carbon residue that fills the micropores of the molecular sieve, thereby obtaining a carrier for introducing carbon residue;
[0058] 4) 40 g of the carrier with residual carbon introduced was taken, and H2PdCl6 was used as a palladium source, and an equal volume of active metal Pd with a mass fraction of 0.2% was impregnated. After drying and calcination, a catalyst was prepared with a residual carbon content of 7.64%.
[0059] Take 10g of the catalysts of Comparative Examples 1-3 and Examples 1-3 above and use them in a fixed bed reactor to evaluate the isomerization and decondensation reaction of the tail oil from Fischer-Tropsch synthesis. Reduction conditions: H2 reduction, reduction pressure 4MPa, reduction temperature 450°C, reduction time 4h, reduction space velocity 3600h -1 .
[0060] The evaluation of raw material properties and operating conditions is shown in Tables 1 to 3, and the catalyst effect is shown in Table 4.
[0061] Table 1 Comparative Example 1, Example 1, raw material properties and operating conditions used for evaluation
[0062]
[0063] Table 2 Comparative Example 2, Example 2, Evaluation of Raw Material Properties and Operating Conditions
[0064]
[0065] Table 3 Comparative Example 3, Example 3, raw material properties and operating conditions used for evaluation
[0066]
[0067] Table 4 Comparative Examples 1-3, Examples 1-3, Evaluation Results
[0068]
[0069]
[0070] Comparative Examples 1-3 use conventional methods to prepare catalysts, while Examples 1-3 use the improved carrier introduction method of the present invention to prepare catalysts. As shown in Table 4, the catalysts prepared by the method of the present invention enhance the isomerization decondensation performance, reduce the secondary cracking of the product, increase the single-pass liquid yield, and increase the single-pass base oil yield while keeping the pour point of the decondensation product almost unchanged. In particular, in the comparison of the evaluation results of Comparative Example 1 and Example 1 using extremely wide distillation range raw materials (200-700°C), the catalyst prepared by the improved method of the present invention can obtain a higher grade (No. 6) base oil that cannot be obtained by the catalyst prepared by the conventional method, thereby greatly increasing the single-pass base oil yield.
[0071] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.
Claims
1. An isomeric pour point depressant catalyst, characterized in that: The invention comprises an active component of a Group VIII noble metal and a modified composite molecular sieve carrier composed of a silicoaluminophosphate molecular sieve, a silicon-alumino molecular sieve and a binder. The active component is loaded on the modified composite molecular sieve carrier. Residual carbon is introduced into the micropores of the modified composite molecular sieve carrier by soaking a residual carbon introducing agent and performing a partial oxidation treatment. The content of the residual carbon is 0.5 to 8.0% of the weight of the catalyst.
2. The isomerized pour point depressing catalyst according to claim 1, characterized in that: The mass percentage of each component in the catalyst is as follows: 0.05-1.0% of Group VIII noble metal, 50-80% of silicoaluminophosphate molecular sieve, 10-30% of silica-alumino molecular sieve, 5-30% of binder and 0.5-8.0% of residual carbon.
3. The isomerized pour point depressing catalyst according to claim 1, characterized in that: The mass percentage of each component in the catalyst is as follows: 0.1-0.3% of Group VIII noble metal, 60-80% of silicoaluminophosphate molecular sieve, 15-30% of silicoalumino molecular sieve, 10-30% of binder and 1.0-6.0% of residual carbon; And / or, the Group VIII noble metal is at least one of Pt, Pd, and Ru, the silicoaluminophosphate molecular sieve is one or more of SAPO-11, SAPO-31, and SAPO-41, the silicoalumino molecular sieve is one or more of ZSM-5, ZSM-22, β-molecular sieve, and SBA-15, and the binder is at least one of aluminum sol, pseudo-boehmite, and silica sol.
4. A method for preparing an isomeric pour point depressant catalyst, characterized in that: The following steps are involved: S1. After mixing the silicoaluminophosphate molecular sieve and the silica-alumino molecular sieve, adding the mixture into an acid solution for modification treatment, followed by filtering, washing, drying and calcining in sequence to obtain an acid-treated mixed molecular sieve; S2, uniformly kneading the acid-treated mixed molecular sieve with a binder and a molding acid, and then sequentially molding, drying, calcining, crushing and screening to obtain a molded modified composite molecular sieve; S3, soaking the above-formed modified composite molecular sieve in a residual carbon introducing agent, filtering after soaking, and then treating at 300-500° C. in an air environment, and through a partial oxidation treatment with rapid heating and a short time, the residual carbon introducing agent is incompletely oxidized in the catalyst pores to form residual carbon filled in the micropores of the carrier, thereby obtaining a carrier with introduced residual carbon; S4, preparing a salt solution of Group VIII noble metals, and immersing the above-mentioned carrier introduced with residual carbon in the salt solution. After the active metal is loaded through immersion, the final catalyst is obtained.
5. The preparation method according to claim 4, characterized in that: In step S3, The residual carbon introducing agent comprises a diluent and a carbon source, wherein the diluent is at least one of C6-C8 normal alkanes with a mass fraction of 20-80%, and the carbon source is at least one of C12-C16 normal alkanes with a mass fraction of 20-80%.
6. The preparation method according to claim 4, characterized in that: In step S3, The conditions for the partial oxidation treatment with rapid temperature increase and short time are controlled as follows: Within 1 to 2 hours, the temperature is raised to a treatment temperature of 300 to 500°C and maintained for 1 to 2 hours.
7. The preparation method according to claim 4, characterized in that: In step S4, The salt solution of the Group VIII noble metal is selected from at least one of chloroplatinic acid, chloropalladic acid, ruthenium trichloride, dichlorotetraammineplatinum, and dichlorotetraamminepalladium.
8. The preparation method according to claim 4, characterized in that: Used for preparing the isomerization pour point depressing catalyst described in any one of claims 1-3.
9. Application of isomerized pour point depressing catalyst, characterized in that: The isomerization depressant catalyst described in any one of claims 1 to 3 or the catalyst prepared by the preparation method described in any one of claims 4 to 7 is used in Fischer-Tropsch synthesis distillate oil.
10. The use according to claim 9, characterized in that: The catalyst catalyzes the isomerization and decondensation reaction of long straight-chain hydrocarbons in the Fischer-Tropsch synthesis fraction oil, thereby preparing the lubricating oil base oil.