Carbon-based nickel-containing catalyst, preparation method and application

Abstract

The invention discloses an isoprene cyclization trimerization method catalyzed by a carbon-based nickel-containing catalyst. The trimerization target product trimethyl cyclododecatriene is high in selectivity, and C16 and more by-products in the product are few.

Description

Technical Field

[0001] The present invention relates to a carbon-based catalyst, a preparation method and an application, and more specifically, to a method for preparing a carbon-based nickel-containing heterogeneous catalyst, a preparation method and a method for preparing trimethylcyclododecatriene by cyclotrimerization of isoprene. Background Art

[0002] Isoprene is one of the olefins produced in the petrochemical production process and is an important organic chemical raw material with a wide range of application prospects. With the rapid development of science and technology, the continuous progress of olefin low molecular weight polymerization technology, such as trimerization, has attracted increasing attention. Among them, the one with the widest application prospect and relatively high industrial value is the trimerization of isoprene to form trimethylcyclododecatriene (TMCDT for short).

[0003] TMCDT is an important organic chemical and fine chemical intermediate with special uses. It can be used to synthesize saturated or unsaturated dibasic acids and their derivatives. It is also a raw material for polyesters, polyamides, plasticizers, flame retardants, macrocyclic organic compounds and certain macrocyclic musks. It has a wide range of industrial application value.

[0004] Isoprene cyclopolymerization catalysts are mainly homogeneous catalysts, and the main problem is that the selectivity of the trimerization target product TMCDT is not high. Summary of the invention

[0005] In order to solve the above problems, a heterogeneous catalyst is a better choice. The purpose of the present invention is to provide a heterogeneous catalyst different from the prior art, and to provide a preparation method thereof and a method for preparing trimethylcyclododecatriene by cyclotrimerization of isoprene.

[0006] Biomass carbon material (BIOC) is a product of high temperature roasting of biomass in the absence of oxygen or oxygen-deficient conditions. It is a nano-carbon material with rich pore structure and large specific surface area. The inventors found that the catalyst obtained by loading nickel compounds on the biomass carbon material BIOC and mixing it with alkyl aluminum chloride to catalyze the cyclopolymerization reaction of isoprene has high selectivity for the trimerization target product TMCDT, and there are few byproducts of C16 and above in the product. Based on this, the present invention is formed.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for preparing a carbon-based nickel-containing catalyst, characterized in that the method comprises: mixing a biomass carbon material BIOC, nickel acetylacetonate and alkylaluminum chloride and an optional solvent for reaction and recovering the product to obtain a carbon-based nickel-containing catalyst.

[0008] More specifically, the method for preparing a carbon-based nickel-containing catalyst provided by the present invention comprises the following steps: under anhydrous and oxygen-free reaction conditions and under nitrogen protection, a carrier biomass carbon material BIOC, nickel acetylacetonate and alkyl aluminum chloride and an optional solvent light aromatic hydrocarbon are mixed, the reaction is stirred at 30-60° C. for 5-30 hours, and the product is optionally recovered to obtain a carbon-based nickel-containing catalyst.

[0009] In the present invention, the biomass carbon material BIOC contains a small amount of oxygen in addition to carbon; based on the total weight of the biomass carbon material BIOC, the carbon content of the biomass carbon material BIOC is 85-99.9% by weight, and the balance is mainly oxygen. Preferably, the biomass carbon material BIOC contains nitrogen in addition to carbon and oxygen; based on the total weight of the biomass carbon material BIOC, the carbon content of the biomass carbon material BIOC is 80-99.9% by weight, the nitrogen content is 0.1-10% by weight, and the balance is oxygen.

[0010] In the present invention, the main source of the biomass carbon material BIOC is the carbon material obtained by carbonizing biomass raw materials such as starch, cellulose, and lignin. For example, in an oxygen-free atmosphere, the above-mentioned biomass raw materials are roasted at 800-1300°C for 2-10h to obtain the biomass carbon material. Alternatively, in an ammonia atmosphere, the above-mentioned biomass raw materials are roasted at 800-1300°C for 2-10h to obtain the biomass carbon material containing nitrogen. The ammonia atmosphere contains ammonia and nitrogen, and the content of ammonia is 0.1-10% by volume.

[0011] In the present invention, the weight ratio of nickel acetylacetonate to biomass carbon material is 2-20, preferably 5-15; the light aromatic hydrocarbons can be selected from benzene, toluene, ethylbenzene, xylene, etc., preferably, the light aromatic hydrocarbons are toluene; the weight ratio of light aromatic hydrocarbons to biomass carbon material is 5-25:1.

[0012] In order to achieve the above-mentioned purpose, the second aspect of the present invention provides a catalyst, which is prepared by the above-mentioned preparation method and consists of a nickel-loaded biomass carbon material BIOC and an alkyl aluminum chloride. Based on the mass of the catalyst (excluding solvent light aromatics, the same below), the nickel content is 2.5-10%, the biomass carbon material BIOC content is 7.5-50%, and the alkyl aluminum chloride content is 50-90%.

[0013] In order to achieve the above-mentioned purpose, the third aspect of the present invention provides a method for the cyclotrimerization of isoprene, which uses isoprene as a raw material, reacts at 60-130°C, preferably 80-100°C, in the presence of the catalyst prepared in the first aspect of the present invention or the catalyst provided in the second aspect of the present invention, to obtain trimethylcyclododecatriene.

[0014] Specifically, the third aspect of the present invention provides a method for cyclotrimerization of isoprene, wherein the reaction is carried out under the protection of an inert gas such as nitrogen, the mass ratio of the solvent light aromatic hydrocarbon, isoprene and the catalyst is 10-200:2-100:1, the reaction temperature is 60-130°C, preferably 80-100°C, the reaction pressure is 0.1-1MPa, and the reaction is stirred for 1-12 hours. After the reaction is completed, under the protection of an inert gas such as nitrogen, a reaction terminator such as methanol is added to the obtained liquid to terminate the reaction, and the reaction product material is subjected to reduced pressure distillation to collect the required fraction product.

[0015] In the present invention, the alkylaluminum chloride is preferably sesquiethylaluminum chloride and / or diethylaluminum chloride, and more preferably sesquiethylaluminum chloride.

[0016] In the present invention, the weight ratio of the alkylaluminum chloride to the nickel-loaded BIOC biomass carbon material is 1-50, preferably 2-25.

[0017] The isoprene cyclopolymerization method provided by the present invention has high selectivity for the trimerization target product TMCDT and less byproducts of C16 and above in the product. DETAILED DESCRIPTION

[0018] The present invention is further described below by way of examples, but the present invention is not limited thereto.

[0019] Examples 1-4 are used to illustrate the carbon-based nickel-containing catalyst and its preparation method provided by the present invention.

[0020] Example 1

[0021] Under the reaction conditions of anhydrous and oxygen-free, 5g of biomass carbon material BIOC sample A1 (the product of lignin calcined and carbonized at 800℃ in an oxygen-free atmosphere for 6h, with a specific surface area of ​​583m 2 / g, the carbon content is 97.1% by weight, the nitrogen content is 1.8% by weight, and the balance is oxygen, the same below), an appropriate amount of nickel acetylacetonate, 20g of sesquiethylaluminum chloride and 200g of toluene are mixed, and the reaction is stirred at 30°C for 24h to obtain catalyst X1, in which the nickel content is 9.8%, the biomass carbon material BIOC content is 34.6%, and the alkylaluminum chloride content is 55.6%.

[0022] Example 2

[0023] Under anhydrous and oxygen-free reaction conditions and under nitrogen protection, 6 g of biomass carbon material BIOC sample A1, an appropriate amount of nickel acetylacetonate, 20 g of diethylaluminum chloride and 300 g of toluene were mixed and stirred at 40°C for 18 hours to obtain catalyst X2, in which the nickel content was 7.7%, the biomass carbon material BIOC content was 35.1%, and the alkylaluminum chloride content was 57.2%.

[0024] Example 3

[0025] The steps are the same as those in Example 1, except that the biomass carbon material BIOC sample A2 (biomass carbon particles modified with ammonia nitrogen: lignin was calcined at 1100°C for 6 h in a 2% by volume ammonia atmosphere, with nitrogen as the balance gas, and the specific surface area of ​​the nanocarbon material was 628 m 2 / g, carbon content is 93.5% by weight, nitrogen content is 3.9% by weight, and the balance is oxygen, the same below) as raw materials. Catalyst X3 is obtained, wherein the nickel content is 9.2%, the biomass carbon material BIOC content is 31.3%, and the alkyl aluminum chloride content is 59.5%.

[0026] Example 4

[0027] The steps are the same as those in Example 2, except that the biomass carbon material BIOC sample A2 is used as the raw material to obtain a catalyst X4, in which the nickel content is 7.5%, the biomass carbon material BIOC content is 39.6%, and the alkyl aluminum chloride content is 52.9%.

[0028] Embodiments 5 to 8

[0029] This example illustrates the isoprene cyclotrimerization method provided by the present invention.

[0030] The reaction was carried out in a high-pressure 500mL Parr reactor. The air in the reactor was replaced with nitrogen three times, and then 100mL toluene, 10g catalyst X1-X4, and 50g isoprene were added to the reactor under nitrogen protection. The temperature was kept at 85°C and the pressure was kept at 0.3MPa. The reaction was stirred for 2 hours. After the reaction was completed, methanol was added to the obtained liquid under nitrogen protection to terminate the reaction. The reaction product was distilled under reduced pressure to collect the required fractions. The fractions were analyzed and calculated by gas chromatography. The selectivity data of each embodiment are as follows:

[0031] With X1 as the catalyst, the selectivity of TMCDT is 83.4%, and the selectivity of by-products of C16 and above is 6.5%.

[0032] With X2 as the catalyst, the selectivity of TMCDT is 80.9%, and the selectivity of by-products of C16 and above is 7.4%.

[0033] With X3 as the catalyst, the selectivity of TMCDT is 89.1%, and the selectivity of by-products of C16 and above is 3.9%.

[0034] With X4 as the catalyst, the selectivity of TMCDT is 88.6%, and the selectivity of by-products of C16 and above is 4.1%.

[0035] Example 9

[0036] The reaction was carried out in a high-pressure 500mL Parr reactor. The air in the reactor was replaced with nitrogen three times, and then 100mL toluene, 2g catalyst X1, and 50g isoprene were added to the reactor under nitrogen protection. The temperature was kept at 65°C and the pressure was kept at 0.5MPa. The reaction was stirred for 6 hours. After the reaction was completed, methanol was added to the obtained liquid under nitrogen protection to terminate the reaction, and the reaction product was distilled under reduced pressure to collect the required fractions. The fractions were analyzed and calculated by gas chromatography, and the selectivity of TMCDT was 86.2%, and the selectivity of by-products of C16 and above was 5.9%.

[0037] Example 10

[0038] The reaction was carried out in a high-pressure 500mL Parr reactor. The air in the reactor was replaced with nitrogen three times, and then 100mL toluene, 5g catalyst X1, and 20g isoprene were added to the reactor under nitrogen protection. The temperature was kept at 105°C and the pressure was kept at 0.2MPa. The reaction was stirred for 4 hours. After the reaction was completed, methanol was added to the obtained liquid under nitrogen protection to terminate the reaction, and the reaction product was distilled under reduced pressure to collect the required fractions. The fractions were analyzed and calculated by gas chromatography, and the selectivity of TMCDT was 73.4%, and the selectivity of by-products of C16 and above was 13.7%.

[0039] Comparative Example 1

[0040] The catalyst was prepared by referring to the method of Example 1, using activated carbon (commercially available from Sinopharm Group, analytically pure, with a C content greater than 99.0%, an ash content less than 1.0%, and a specific surface area of ​​962 m 2 / g) to replace the biomass carbon material BIOC sample A1 to obtain a comparative catalyst sample with the same nickel content, numbered D1.

[0041] Comparative Example 2

[0042] The reaction was carried out in accordance with the method of Example 5, except that the same mass of D1 was used instead of X1. The fractions were analyzed and calculated by gas chromatography, and the selectivity of the catalyst for TMCDT was 51.3%, and the selectivity for byproducts of C16 and above was 40.6%.

Claims

1. A method for preparing a carbon-based nickel-containing catalyst, characterized in that: The method comprises: mixing biomass carbon material BIOC, nickel acetylacetonate and alkyl aluminum chloride and an optionally added solvent for reaction and recovering the product to obtain a carbon-based nickel-containing catalyst.

2. The preparation method according to claim 1, characterized in that: Based on the total weight of the biomass carbon material BIOC, the carbon content is 85-99.9% by weight, and the remainder is mainly oxygen.

3. The preparation method according to claim 1, characterized in that: The biomass carbon material BIOC also contains nitrogen; based on the total weight of the biomass carbon material BIOC, the carbon content is 80-99.9% by weight, the nitrogen content is 0.1-10% by weight, and the balance is oxygen.

4. The preparation method according to claim 1, characterized in that: The weight ratio of nickel acetylacetonate to biomass carbon material BIOC is 2-20.

5. The preparation method according to claim 4, characterized in that: The weight ratio of nickel acetylacetonate to BIOC biomass carbon material is 5-15.

6. The preparation method according to claim 1, characterized in that: The solvent that can be optionally added is a light aromatic hydrocarbon selected from benzene, toluene, ethylbenzene, and xylene, preferably toluene.

7. The preparation method according to claim 1, characterized in that: The alkylaluminum chloride is sesquiethylaluminum chloride and / or diethylaluminum monochloride.

8. The preparation method according to claim 1, characterized in that: The mass molar ratio of the alkyl aluminum chloride to the biomass carbon material BIOC is 1-50.

9. A carbon-based nickel-containing catalyst obtained by the preparation method according to any one of claims 1 to 8.

10. A carbon-based nickel-containing catalyst, characterized in that: The catalyst consists of nickel-loaded biomass carbon material BIOC and alkyl aluminum chloride. Based on the mass of the catalyst, the nickel content is 2.5-10%, the biomass carbon material BIOC content is 7.5-50%, and the alkyl aluminum chloride content is 50-90%.

11. The catalyst according to claim 10, characterized in that The mass content of alkylaluminum chloride is 50-95%.

12. A method for cyclotrimerization of isoprene, characterized in that: The method uses isoprene as a raw material, reacts in the presence of the carbon-based nickel-containing catalyst of claim 9 or 10 at 60-130° C., and obtains trimethylcyclododecatriene.