A catalyst for propylene and butene oligomerization reaction, its preparation method and application
By using a catalyst system composed of molecular sieves, metal oxides, and alumina, the problems of high cost and easy corrosion of existing catalysts are solved, and olefin oligomerization reactions with high conversion rate and high selectivity are achieved, which is suitable for heterogeneous catalytic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 淄博容科化工技术有限公司
- Filing Date
- 2023-10-20
- Publication Date
- 2026-06-23
AI Technical Summary
Existing catalysts for olefin oligomerization have problems such as high cost, low conversion rate, harsh conditions, easy mud formation, and strong corrosiveness to equipment.
A catalyst system using molecular sieves as the main catalyst, metal oxides as co-catalysts, and alumina as a binder is used to prepare the catalyst through a specific preparation method, including mixing, kneading, extruding, and calcining of molecular sieves with metal salt solutions to form round or clover-shaped catalysts.
It achieves high conversion rates (≥85%) of propylene and butene, high selectivity for dimerization and trimerization (≥80%), long single-pass operating cycle, and good sulfur resistance, making it suitable for multiphase oligomerization reactors.
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Figure BDA0004504181250000081
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, specifically relating to a catalyst for the oligomerization reaction of propylene and butene, its preparation method and application, and particularly to the application of the catalyst in catalyzing the oligomerization reaction of propylene to prepare trimers of hexene, nonene and dodecene, or in catalyzing the oligomerization reaction of butene to prepare dimers of octene and dodecene. Background Technology
[0002] Petroleum processing and high-temperature Fischer-Tropsch synthesis reactions generate large amounts of propylene and butene. With the increasing market demand for propylene and butene, new technologies for producing propylene and butene are also constantly being updated. Propane dehydrogenation, coal-to-olefins, and methanol-to-olefins projects are being promoted, and the output of propylene and butene is showing a steady upward trend. In order to adapt to market changes, the comprehensive utilization of propylene and butene, extending the industrial chain, and increasing the added value of products have become research hotspots.
[0003] Olefin oligomerization refers to the reaction in which a small number of olefin monomers polymerize under certain conditions into compounds with multiple interconnected structural units. Olefin oligomerization is an important method for the comprehensive utilization of propylene and butene. The linear and higher linear olefins produced have a wide range of industrial applications, serving not only as liquid fuel additives but also as important raw materials for the production of chemical products. The oligomerized products, after separation, can be used to produce plastics, plasticizers, lubricants, and surfactants. Furthermore, these olefins can be used to prepare higher alcohols through carbonylation and hydrogenation reactions, which have broad applications.
[0004] Both homogeneous and heterogeneous catalysts can induce dimerization or polymerization of low-carbon olefins. Heterogeneous catalysis, in particular, has gained widespread attention due to the elimination of the need for post-reaction separation of catalyst and product. Among heterogeneous catalysts, nickel complex catalysts based on ionic liquid catalytic systems offer advantages such as easy separation and good stability, but are expensive and difficult to control under specific operating conditions. Solid phosphoric acid catalysts, while simple to prepare, are prone to mud formation, clogging pipelines, and corroding equipment during use. Molecular sieve-catalyzed olefin oligomerization suffers from drawbacks such as carbon buildup, pore blockage, and short regeneration cycles. Therefore, developing catalysts with high activity and high stability is an urgent problem to be solved.
[0005] In the prior art, some improvement schemes have been proposed to address the above-mentioned technical problems, but they suffer from low reaction conversion rates. For example, Chinese patent (publication number 111617799A) reports a novel catalyst for propylene oligomerization and its preparation method, using molecular sieves as a support, MO... x With nickel oxide as the active component, MO is first introduced through precipitation. x After being combined with a carrier and calcined, SO4 is then introduced. 2- Ion pairs MO xAfter sulfation and calcination, it is prepared by nickel ion exchange with a nickel salt precursor solution and used for propylene oligomerization reaction. The conversion rate of propylene is 60-75% and the selectivity of nonene is 40-55%. Summary of the Invention
[0006] To address the problems of high cost, low conversion rate, harsh conditions, easy mud formation, and corrosiveness to equipment in existing catalysts used for olefin oligomerization, this invention provides a catalyst for propylene and butene oligomerization, its preparation method, and its application. This catalyst has advantages such as high conversion rate, long single-pass service life, and good sulfur resistance, and its preparation method is simple and has strong applicability.
[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows.
[0008] The present invention provides a catalyst for the oligomerization reaction of propylene and butene, comprising 70wt% to 80wt% of a main catalyst, 2wt% to 3wt% of a co-catalyst and 18wt% to 27wt% of alumina; wherein the main catalyst is a molecular sieve, the co-catalyst is a metal oxide and the binder is alumina.
[0009] Preferably, the molecular sieve is one or both of ZSM-5 and MCM-22;
[0010] More preferably, the ZSM-5 molecular sieve is of the ammonium type, with a silicon-to-aluminum ratio of 50 to 120, a relative crystallinity >95%, and a Na2O content <0.05%;
[0011] Particularly preferred is that the silicon-to-aluminum ratio of the ZSM-5 molecular sieve is 65–100;
[0012] More preferably, the selected MCM-22 molecular sieve is in the hydrogen form, with a silica-to-alumina ratio of 25–50, a relative crystallinity >90%, a Na₂O content <0.05%, and a specific surface area >300 m². 2 / g;
[0013] Particularly preferred is that the silicon-to-aluminum ratio of the MCM-22 is 30 to 40.
[0014] Preferably, the metal oxide is one or more selected from NiO, MnO, CoO, ZnO, Fe2O3, and Al2O3.
[0015] Preferably, the metal oxide is derived from a salt of the corresponding metal element;
[0016] More preferably, the salt of the corresponding metal element is a nitrate, sulfate, acetate or chloride salt of the corresponding metal element;
[0017] Preferably, the salt of the corresponding metal element is a nitrate or acetate of the corresponding metal element.
[0018] Preferably, the binder is derived from small-pore boehmite with a specific surface area > 260 m². 2 / g, Na2O content <0.1%, SiO2 content <0.15%, colloidal index >95%.
[0019] Preferably, the catalyst is in the shape of a round bar or a clover.
[0020] Preferably, the catalyst has a size of 2-3 mm and a specific surface area > 300 m². 2 / g, Na2O content <0.1%.
[0021] The present invention also provides a method for preparing the above-mentioned catalyst for the oligomerization reaction of propylene and butene, comprising the following steps:
[0022] 1) At 20–40°C, the molecular sieve powder is mixed with deionized water and stirred until it becomes a slurry to obtain a molecular sieve solution;
[0023] 2) Dissolve the salt of the metal element corresponding to the metal oxide in deionized water to obtain a metal salt solution;
[0024] The amount of salt of the corresponding metal element is calculated based on the content of metal oxide, and the mass ratio of metal oxide to molecular sieve powder in step 1) is 2.5 to 4:100.
[0025] 3) At 20-40℃, the metal salt solution prepared in step 2) is added to the molecular sieve slurry prepared in step 1) at a uniform rate over a period of 10-15 minutes. After the addition is complete, stirring is continued for more than 2 hours, followed by filtration and drying to obtain the modified molecular sieve.
[0026] 4) The modified molecular sieve, binder raw materials and guar gum powder are mixed evenly at a mass ratio of 100:32-40:3-5, and kneaded with citric acid aqueous solution. The kneaded material is extruded, dried and calcined to obtain a catalyst for the oligomerization reaction of propylene and butene.
[0027] The mass ratio of citric acid to modified molecular sieve in the citric acid aqueous solution is 2-4:100.
[0028] Preferably, in step 1), the molecular sieve powder and deionized water are mixed at a mass ratio of 1:1 to 1.2, and the stirring speed is controlled at 100 to 200 r / min.
[0029] Preferably, in step 2), the amount of deionized water used is 40-50% of the mass of the molecular sieve powder in step 1).
[0030] Preferably, in step 3), the drying temperature is 110–120°C and the drying time is 4 hours.
[0031] Preferably, in step 4), the mass ratio of deionized water to modified molecular sieve in the citric acid aqueous solution is 35-40:100.
[0032] Preferably, in step 4), the drying temperature is 150–160°C and the drying time is 4 hours.
[0033] Preferably, in step 4), the calcination temperature is 540–560°C and the calcination time is 4 hours.
[0034] The present invention also provides the application of the above catalyst in the preparation of trimers of hexene, nonene and dodecene by catalytic oligomerization of propylene, or in the preparation of dimers of octene and dodecene by catalytic oligomerization of butene.
[0035] Preferably, the catalytic reaction is carried out at a temperature of 200–400°C, a pressure of 1–3 MPa, and a weight hourly space velocity of 2–3 h⁻¹. -1 .
[0036] Preferably, the conversion rates of propylene and butene are both >85%, and the selectivity of dimers and trimers is both >80%.
[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0038] The catalyst of the present invention for the oligomerization reaction of propylene and butene uses molecular sieve as the main catalyst, metal oxide as the co-catalyst, and alumina as the binder. It is used to catalyze the oligomerization reaction of propylene or butene and has the advantages of high conversion rate of propylene and butene reaction (conversion rate > 85%), high selectivity of dimerization and trimerization (selectivity > 80%), long single-pass use cycle, good sulfur resistance, and easy subsequent separation.
[0039] The catalyst preparation method of the present invention for the oligomerization reaction of propylene and butene is simple and highly applicable, and can be used in most multiphase oligomerization reaction devices. Detailed Implementation
[0040] To further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.
[0041] The catalyst of the present invention for the oligomerization reaction of propylene and butene comprises 70wt% to 80wt% of a main catalyst, 2wt% to 3wt% of a co-catalyst and 18wt% to 27wt% of a binder; wherein the main catalyst is a molecular sieve, the co-catalyst is a metal oxide and the binder is alumina.
[0042] In the above technical solution, the molecular sieve is one or both of ZSM-5 and MCM-22; the ZSM-5 molecular sieve is ammonium type, with a silicon-to-aluminum ratio of 50-120, preferably 65-100, relative crystallinity >95%, and Na2O content <0.05%; the MCM-22 molecular sieve is hydrogen type, with a silicon-to-aluminum ratio of 25-50, relative crystallinity >90%, Na2O content <0.05%, and specific surface area >300 m². 2 / g; The silicon-to-aluminum ratio of MCM-22 is 30-40.
[0043] In the above technical solution, the metal oxide is one or more of NiO, MnO, CoO, ZnO, Fe2O3, and Al2O3. The metal oxide is derived from the salt of the corresponding metal element, such as nitrate, sulfate, acetate, or chloride; preferably nitrate or acetate.
[0044] In the above technical solution, the binder is derived from small-pore boehmite, which has a specific surface area > 260 m². 2 / g, Na2O content <0.1%, SiO2 content <0.15%, colloidal index >95%.
[0045] In the above technical solution, the catalyst is round or clover-shaped, with a size of 2-3 mm and a specific surface area > 300 m². 2 / g, Na2O content <0.1%.
[0046] The preparation method of the catalyst for the oligomerization reaction of propylene and butene according to the present invention comprises the following steps:
[0047] 1) At 20–40°C, the molecular sieve powder is mixed with deionized water and stirred until it becomes a slurry to obtain a molecular sieve solution;
[0048] 2) Dissolve the salt of the metal element corresponding to the metal oxide in deionized water to obtain a metal salt solution;
[0049] 3) At 20-40℃, the metal salt solution prepared in step 2) is added to the molecular sieve slurry prepared in step 1) at a uniform rate over a period of 10-15 minutes. After the addition is complete, stirring is continued for more than 2 hours, followed by filtration and drying to obtain the modified molecular sieve.
[0050] 4) The modified molecular sieve, binder raw materials and guar gum powder are mixed evenly at a mass ratio of 100:32-40:3-5, and kneaded with citric acid aqueous solution. The kneaded material is extruded, dried and calcined to obtain a catalyst for the oligomerization reaction of propylene and butene.
[0051] In the above technical solution, in step 1), molecular sieve powder and deionized water are mixed at a mass ratio of 1:1 to 1.2, and the stirring speed is preferably controlled at 100 to 200 r / min.
[0052] In the above technical solution, in step 2), the amount of salt corresponding to the metal element is calculated based on the content of metal oxide, and the mass ratio of metal oxide to molecular sieve powder is 2.5 to 4:100; the amount of deionized water is 40 to 50% of the mass of molecular sieve powder in step 1).
[0053] In the above technical solution, step 3) typically involves vacuum filtration. The drying temperature is 110–120°C, and the drying time is 4 hours.
[0054] In the above technical solution, in step 4), the mass ratio of citric acid to modified molecular sieve in the citric acid aqueous solution is 2-4:100. The mass ratio of deionized water to modified molecular sieve in the citric acid aqueous solution is 35-40:100. The drying temperature is 150-160℃, and the drying time is 4 hours. The calcination temperature is 540-560℃, and the calcination time is 4 hours.
[0055] The catalyst of the present invention can be used to prepare trimers of hexene, nonene and dodecene by catalytic oligomerization of propylene, or to prepare dimers of octene and dodecene by catalytic oligomerization of butene.
[0056] In the above technical solution, the catalytic reaction temperature is 200–400℃, the pressure is 1–3 MPa, and the weight hourly space velocity is 2–3 h⁻¹. -1 The conversion rates of propylene and butene are both >85%, and the selectivity of dimers and trimers is both >80%.
[0057] The terminology used in this invention generally has the meanings commonly understood by those skilled in the art, unless otherwise stated.
[0058] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to embodiments.
[0059] In the following embodiments, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, apparatus, instruments, equipment, etc., used in the following embodiments are commercially available.
[0060] Example 1
[0061] 1) Add 450g of deionized water to a 1L beaker, turn on the stirrer, set the stirring speed to 100-150r / min, and add 400g of ammonium type ZSM-5 molecular sieve powder (silicon-aluminum ratio 72) to the deionized water under stirring at 30-35℃ until the molecular sieve powder becomes a slurry. Continue stirring for 10-15min.
[0062] 2) Dissolve 46g of nickel nitrate hexahydrate in 160g of deionized water, transfer it to a dropping funnel, and add it at a constant rate to the slurry in step 1) under stirring conditions at 30-35℃ for 10-15 minutes, and continue stirring for 2 hours;
[0063] 3) The slurry was filtered, and the filter cake was dried at 110-120℃ for 4 hours to obtain 405.28g of modified molecular sieve;
[0064] 4) Mix 405.28g of modified molecular sieve, 16g of guar gum powder and 150g of small-pore boehmite evenly;
[0065] 5) Dissolve 12g of citric acid in 160g of deionized water, pour it into the above mixed powder and knead for 30-40 minutes;
[0066] 6) The kneaded material is extruded into 3mm round strips using an extruder, dried at 150-160℃ for 4 hours, and calcined at 540-560℃ for 4 hours to obtain oligomerization catalyst QJ-01.
[0067] Example 2
[0068] The catalyst was prepared according to the operating steps in Example 1. The silicon-to-aluminum ratio of the ammonium-type ZSM-5 molecular sieve powder was changed to 98, and 46g of nickel nitrate hexahydrate was changed to 40g of zinc nitrate hexahydrate, resulting in 398.42g of modified molecular sieve, which was then prepared as oligomerization catalyst QJ-02.
[0069] Example 3
[0070] The catalyst was prepared according to the operating steps in Example 1. The ammonium type ZSM-5 molecular sieve powder was replaced with hydrogen type MCM-22 molecular sieve powder (silicon-aluminum ratio 27), and 46g of nickel hexahydrate was replaced with 45g of aluminum nonahydrate, resulting in 415.76g of modified molecular sieve, which was then prepared as oligomerization catalyst QJ-03.
[0071] Example 4
[0072] 30g of oligomerization catalysts QJ-01, QJ-02, and QJ-03 were respectively packed into a fixed-bed reactor. Oligomerization was carried out using feedstock 1 (0.05% C3, 81.89% butane, 17.16% butene, and 0.9% C5) at a reaction pressure of 1 MPa, a reaction temperature of 280℃, and a weight hourly space velocity of 2 h⁻¹. -1 The reaction results are shown in Table 1.
[0073] Example 5
[0074] 30g of oligomerization catalysts QJ-01, QJ-02, and QJ-03 were respectively packed into a fixed-bed reactor. Oligomerization was carried out using feedstock II (C2 2.25%, propane 70.69%, propylene 26.86%, C4 0.2%). The reaction pressure was 2 MPa, the reaction temperature was 220℃, and the weight hourly space velocity was 3 h⁻¹. -1 The reaction results are shown in Table 1.
[0075] Example 6
[0076] 30g of oligomerization catalysts QJ-01, QJ-02, and QJ-03 were respectively packed into a fixed-bed reactor. Oligomerization was carried out by mixing raw material one and raw material two at a 1:1 mass ratio under the following conditions: reaction pressure 2 MPa, reaction temperature 260℃, and weight hourly space velocity 2 h⁻¹. -1 The reaction results are shown in Table 1.
[0077] Table 1. Reaction conditions and results of different catalysts for oligomerization.
[0078]
[0079] As can be seen from the data in Table 1, the catalyst prepared in this invention has a high conversion rate when used for the oligomerization reaction of propylene and butene. When the raw material is a single propylene or butene, the selectivity of dimers and trimers in the product is high. However, when a mixed raw material of propylene and butene is used for the oligomerization reaction, the selectivity of dimers and trimers of propylene and butene in the product is low. Therefore, it is not suitable for the mixed oligomerization reaction of propylene and butene.
[0080] Obviously, the above embodiments are merely examples for clear illustration and are not intended to limit the embodiments. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. The application of a catalyst in the catalytic oligomerization of propylene to prepare hexene, nonene, and dodecene, or in the catalytic oligomerization of butene to prepare octene and dodecene, characterized in that, The catalyst consists of 70wt%–80wt% of a main catalyst, 2wt%–3wt% of a co-catalyst, and 18wt%–27wt% of alumina; the main catalyst is a molecular sieve, the co-catalyst is a metal oxide, and the binder is alumina. The molecular sieve is one or two of ZSM-5 and MCM-22; the metal oxide is one or two of ZnO and Al2O3. The ZSM-5 molecular sieve is of the ammonium form, with a silica-to-alumina ratio of 50–120, relative crystallinity >95%, and Na₂O content <0.05%; the selected MCM-22 molecular sieve is of the hydrogen form, with a silica-to-alumina ratio of 25–50, relative crystallinity >90%, Na₂O content <0.05%, and specific surface area >300 m². 2 / g.
2. The application according to claim 1, characterized in that, The metal oxide is derived from the salt of the corresponding metal element; The binder is derived from small-pore boehmite with a specific surface area >260 m². 2 / g, Na2O content <0.1%, SiO2 content <0.15%, colloidal index >95%.
3. The application according to claim 2, characterized in that, The metal oxide is derived from the nitrate, sulfate, acetate or chloride salt of the corresponding metal element.
4. The application according to claim 1, characterized in that, The catalyst is cylindrical or clover-shaped, with a size of 2-3 mm and a specific surface area >300 m². 2 / g, Na2O content <0.1%.
5. The application according to any one of claims 1-4, characterized in that, The catalyst preparation process is as follows: 1) At 20–40°C, the molecular sieve powder is mixed with deionized water and stirred until it becomes a slurry to obtain a molecular sieve solution; 2) Dissolve the salt of the metal element corresponding to the metal oxide in deionized water to obtain a metal salt solution; The amount of salt of the corresponding metal element is calculated based on the content of metal oxide, and the mass ratio of metal oxide to molecular sieve powder in step 1) is 2.5 to 4:
100. 3) At 20-40℃, the metal salt solution prepared in step 2) is added to the molecular sieve slurry prepared in step 1) at a uniform rate over a period of 10-15 minutes. After the addition is complete, stirring is continued for more than 2 hours, followed by filtration and drying to obtain the modified molecular sieve. 4) The modified molecular sieve, binder raw materials and guar gum powder are mixed evenly at a mass ratio of 100:32-40:3-5, and kneaded with citric acid aqueous solution. The kneaded material is extruded, dried and calcined to obtain the catalyst. The mass ratio of citric acid to modified molecular sieve in the citric acid aqueous solution is 2-4:
100.
6. The application according to claim 5, characterized in that, In step 1), molecular sieve powder and deionized water are mixed at a mass ratio of 1:1 to 1.2, and the stirring speed is controlled at 100 to 200 r / min. In step 2), the amount of deionized water used is 40-50% of the mass of the molecular sieve powder in step 1); In step 3), the drying temperature is 110–120°C, and the drying time is 4 hours. In step 4), the mass ratio of deionized water in the citric acid aqueous solution to the modified molecular sieve is 35-40:100; the drying temperature is 150-160℃ and the drying time is 4h; the calcination temperature is 540-560℃ and the calcination time is 4h.
7. The application according to claim 6, characterized in that, The catalytic reaction temperature is 200–400℃, the pressure is 1–3 MPa, and the weight hourly space velocity is 2–3 h⁻¹. -1 .