Catalyst for efficiently synthesizing internal olefin from long-chain-end olefin and preparation method thereof

Abstract

The invention provides a catalyst for efficiently synthesizing internal olefin from long-chain end olefin, the catalyst is composed of a molecular sieve and a perovskite active component, the perovskite active component refers to transition metal-loaded perovskite, and the weight dosage of the perovskite active component is not lower than that of the molecular sieve. The preparation method of the catalyst comprises the following steps: pretreating the molecular sieve, carrying out ultrasonic impregnation loading on a transition metal salt solution and perovskite, drying and roasting to obtain a perovskite active component, finally mixing the molecular sieve and the perovskite active component, grinding, crushing and roasting to obtain the catalyst. The catalyst provided by the invention can realize isomerization of long-chain end olefin double bonds to obtain internal olefin, and meets isomerization processing of high-carbon-number straight-chain olefin. The preparation method of the catalyst is simple, the obtained catalyst is used for preparing internal olefin, the conversion rate is high, the reaction temperature is low, and the cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of internal olefin catalyst preparation, and in particular to a method for synthesizing an ASA catalyst from terminal olefins. Background Art

[0002] Alkenyl succinic anhydride, referred to as ASA, is widely used as a basic raw material for light and fine chemicals, especially as a basic raw material for sizing agents, emulsifiers, lubricants and dispersants. The long-chain groups in the ASA molecule are good hydrophobic groups with good water resistance. The longer the hydrophobic group, the better the sizing effect. ASA made from terminal olefins is solid at room temperature and difficult to emulsify. ASA made from internal olefins is liquid, which is easy to apply sizing. In the field of papermaking, it is an efficient internal sizing agent for paper pulp, which can greatly improve the wear resistance, water resistance and tensile strength of finished paper. The preparation of ASA is divided into two steps. The first step is to synthesize internal olefins by isomerization of terminal olefins, and then react internal olefins with maleic anhydride to obtain ASA.

[0003] Chinese patent CN114433197A discloses a supported metal catalyst for olefin isomerization reaction and its preparation method, the catalyst includes: silicon-aluminum type molecular sieve and supported metal thereon, the catalyst is prepared by first preparing a dealuminated molecular sieve, then mixed with organic amine template, water and supported metal, crystallization step, and the obtained slurry is subjected to cleaning step, ammonium exchange step, roasting step, so as to obtain the catalyst. Due to its higher silicon-aluminum ratio and abundant mesoporous volume, uniformly dispersed active metal, the catalyst can maintain the higher isomerization activity and isomerized olefin product yield of normal olefins in a longer single-pass operation cycle, and can effectively solve the contradiction between carbon deposition and isomerization activity in the prior art. However, the catalyst can only be used for catalyzing the isomerization reaction of short-chain terminal olefins such as C4-C12 straight-chain olefins, and is particularly suitable for low-carbon olefins such as C5 olefins, and is not suitable for the catalytic isomerization reaction of long-chain terminal olefins. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a new catalyst capable of converting long-chain terminal olefins into internal olefins and a preparation method thereof, so as to solve the above-mentioned defects existing in the prior art.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] The first aspect of the present invention is to provide a catalyst for efficiently synthesizing internal olefins from long-chain terminal olefins, which is composed of the following components: a molecular sieve and a perovskite active component, wherein the perovskite active component refers to a perovskite loaded with a transition metal, wherein the weight amount of the perovskite active component is not less than the weight amount of the molecular sieve.

[0007] The molecular sieve is selected from at least one of 4A type, Y type or ZSM-5, preferably ZSM-5. The pore size of the molecular sieve is 0.1-20 nm, and the particle size is 40-120 mesh.

[0008] The perovskite refers to calcium titanate (CaTiO3).

[0009] The transition metal is selected from at least one of iron, cobalt and nickel, and the loading amount of the transition metal is 0.5-7 wt %, calculated based on the weight of the loaded metal oxide and based on the weight of the perovskite.

[0010] The mass ratio of the molecular sieve to the perovskite active component is preferably 1:1-8.

[0011] The second aspect of the present invention is to provide a method for preparing the catalyst for efficiently synthesizing internal olefins from long-chain terminal olefins, comprising the following steps:

[0012] S1, drying and calcining the molecular sieve for pretreatment to remove impurities therein;

[0013] S2, mixing the transition metal salt solution with the perovskite, performing ultrasonic impregnation loading, and then drying and calcining to obtain the perovskite active component;

[0014] S3, mixing the pretreated molecular sieve with the perovskite active component, grinding, crushing and roasting to obtain the catalyst.

[0015] In each step, the drying temperature is 95-105°C, and the roasting temperature is 500-900°C.

[0016] In step S2, the ultrasonic immersion time is 0.5-2h.

[0017] The transition metal is selected from at least one of iron, cobalt and nickel, and is added in the form of a salt solution thereof, including but not limited to an aqueous solution of nitrate, sulfate and hydrochloride.

[0018] In step S3, the mass ratio of the molecular sieve to the perovskite active component is 1:1-8.

[0019] The terminal olefin is R n -CH=CH2, wherein R is a straight chain alkyl group, and n=12-25.

[0020] Through the above technical scheme, the present invention provides a catalyst capable of isomerizing the double bonds of long-chain terminal olefins to obtain internal olefins, which satisfies the isomerization processing of high-carbon linear olefins. The catalyst preparation method is simple, and the obtained catalyst is used to prepare internal olefins, with high conversion rate, low reaction temperature, and cost saving. DETAILED DESCRIPTION

[0021] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only used as examples, but are not used to limit the scope of the present invention. Those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0022] The instruments or raw materials in the present invention without indicating the manufacturer are all conventional commercial instruments or raw materials.

[0023] Unless otherwise mentioned, the detection indicators involved in the embodiments of the present invention are detected by conventional detection methods in the art.

[0024] Example 1

[0025] 1. Dry and calcine the ZSM-5 molecular sieve for pretreatment to remove impurities;

[0026] 2. Mix the ferric nitrate aqueous solution with the perovskite and perform ultrasonic impregnation loading, followed by drying and calcination to obtain the perovskite active component;

[0027] 3. Mixing the pretreated molecular sieve with the perovskite active component, grinding, crushing and roasting to obtain the catalyst;

[0028] The average pore size of the molecular sieve is 10 nm, the average particle size is 60 mesh, the iron loading is 0.5 wt% (calculated as iron oxide and based on the weight of perovskite), the ultrasonic impregnation time is 0.5 h, the mass ratio of perovskite active component to molecular sieve is 1:1, the drying temperature is 105 ° C, and the calcination temperature is 500 ° C.

[0029] The obtained catalyst was used for a synthesis experiment of preparing internal olefins from C16 linear terminal olefins. The specific method is as follows:

[0030] The catalyst prepared by the above method was loaded into a fixed bed reactor, and the vaporized terminal olefins were introduced into the reactor at a reaction space velocity of 0.2 h -1 , and after cooling, the isomerization product internal olefin is obtained.

[0031] The reaction temperature and product conversion rate are shown in the following table:

[0032] project Reaction temperature Conversion rate data 130℃ 97.8％

[0033] Example 2

[0034] 1. Dry and calcine the ZSM-5 molecular sieve for pretreatment to remove impurities;

[0035] 2. Mixing the cobalt nitrate aqueous solution with the perovskite, and then ultrasonically impregnating and loading the mixture, followed by drying and calcining to obtain the perovskite active component;

[0036] 3. Mixing the pretreated molecular sieve with the perovskite active component, grinding, crushing and roasting to obtain the catalyst;

[0037] The average pore size of the molecular sieve is 2 nm, the average particle size is 40 mesh, the cobalt loading is 3 wt% (calculated as cobalt oxide and based on the weight of perovskite), the ultrasonic impregnation time is 1 h, the mass ratio of perovskite active component to molecular sieve is 3:1, the drying temperature is 105 ° C, and the calcination temperature is 700 ° C.

[0038] The obtained catalyst was used to carry out a synthesis experiment of preparing internal olefins from C18 linear terminal olefins. The specific method is as follows:

[0039] The catalyst prepared by the above method was loaded into a fixed bed reactor, and the vaporized terminal olefins were introduced into the reactor at a reaction space velocity of 0.2 h -1 , and after cooling, the isomerization product internal olefin is obtained.

[0040] The reaction temperature and product conversion rate are shown in the following table:

[0041] project Reaction temperature Conversion rate data 130℃ 98.2％

[0042] Example 3

[0043] 1. Dry and calcine the ZSM-5 molecular sieve for pretreatment to remove impurities;

[0044] 2. Mix the nickel nitrate aqueous solution with the perovskite and perform ultrasonic impregnation loading, followed by drying and calcination to obtain the perovskite active component;

[0045] 3. Mixing the pretreated molecular sieve with the perovskite active component, grinding, crushing and roasting to obtain the catalyst;

[0046] The average pore size of the molecular sieve is 18 nm, the average particle size is 100 mesh, the nickel loading is 7 wt% (calculated as nickel oxide and based on the weight of perovskite), the ultrasonic impregnation time is 2 h, the mass ratio of perovskite active component to molecular sieve is 8:1, the drying temperature is 105 ° C, and the calcination temperature is 900 ° C.

[0047] The obtained catalyst was used for a synthesis experiment of preparing internal olefins from C24 linear terminal olefins. The specific method is as follows:

[0048] The catalyst prepared by the above method was loaded into a fixed bed reactor, and the vaporized terminal olefins were introduced into the reactor at a reaction space velocity of 0.2 h -1 , and after cooling, the isomerization product internal olefin is obtained.

[0049] The reaction temperature and product conversion rate are shown in the following table:

[0050] project Reaction temperature Conversion rate data 130℃ 98.8％

[0051] Comparative Example

[0052] A common catalyst (Ni / Cu / γ-Al2O3) was used to synthesize internal olefins from C18 linear terminal olefins. The specific method is as follows:

[0053] The fixed bed reactor was filled with a common catalyst and the vaporized terminal olefins were introduced into the reactor at a reaction space velocity of 0.2 h -1 , and the isomerized product internal olefin is obtained after cooling. The reaction temperature and the conversion rate of the product are shown in the following table:

[0054] project Reaction temperature Conversion rate data 250℃ 82.4％

[0055] It can be seen from the test results that the catalyst of the present invention can be used for the efficient isomerization of long-chain terminal olefins to synthesize internal olefins, and compared with conventional catalysts, it has the advantages of low reaction temperature and high conversion rate.

[0056] It should be understood by those skilled in the art that the above embodiments are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A catalyst for efficiently synthesizing internal olefins from long-chain terminal olefins, characterized in that: The invention is composed of the following components: a molecular sieve and a perovskite active component, wherein the perovskite active component refers to a perovskite loaded with a transition metal, wherein the weight amount of the perovskite active component is not less than the weight amount of the molecular sieve.

2. The catalyst according to claim 1, characterized in that The molecular sieve is selected from at least one of 4A type, Y type or ZSM-5.

3. The catalyst according to claim 1, characterized in that The pore size of the molecular sieve is 0.1-20 nm, and the particle size is 40-120 meshes.

4. The catalyst according to claim 1, characterized in that The perovskite is calcium titanate.

5. The catalyst according to claim 1, characterized in that The transition metal is selected from at least one of iron, cobalt and nickel, and the loading amount of the transition metal is 0.5-7wt%.

6. The catalyst according to claim 1, characterized in that The mass ratio of the molecular sieve to the perovskite active component is 1:1-8.

7. A method for preparing a catalyst for efficiently synthesizing internal olefins from long-chain terminal olefins as claimed in claim 1, characterized in that: The steps include: S1, drying and calcining the molecular sieve for pretreatment to remove impurities therein; S2, mixing the transition metal salt solution with the perovskite, performing ultrasonic impregnation loading, and then drying and calcining to obtain the perovskite active component; S3, mixing the pretreated molecular sieve with the perovskite active component, grinding, crushing and roasting to obtain the catalyst.

8. The method according to claim 7, characterized in that In each step, the drying temperature is 95-105°C, and the roasting temperature is 500-900°C.

9. The method according to claim 7, characterized in that In step S2, the ultrasonic immersion time is 0.5-2h.

10. The method according to claim 7, characterized in that The terminal olefin is R n -CH=CH2, wherein R is a straight chain alkyl group, and n=12-25.