Carbon-based nickel-containing catalyst, method of preparation and use
The heterogeneous catalyst prepared by supporting nickel compounds with alkyl aluminum chloride on biomass carbon material BIOC solves the problem of low selectivity of homogeneous catalysts and achieves high selectivity and low by-products in the isoprene cyclization trimerization reaction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2023-10-31
- Publication Date
- 2026-07-14
AI Technical Summary
In existing isoprene cyclization trimerization reactions, homogeneous catalysts do not produce high selectivity for the trimerized target product TMCDT and produce many byproducts.
A heterogeneous catalyst consisting of a mixture of nickel compounds and alkyl aluminum chloride supported on biomass carbon material BIOC was prepared by high-temperature calcination under anaerobic or oxygen-deficient conditions, and was used for the cyclization trimerization reaction of isoprene.
It improves the selectivity of trimethylcyclododecanetriene, reduces C16 and above byproducts, and achieves a highly efficient isoprene cyclization trimerization reaction.
Abstract
Description
Technical Field
[0001] This invention relates to a carbon-based catalyst, its preparation method, and its application. More specifically, this invention relates to the preparation of a carbon-based nickel-containing heterogeneous catalyst, its preparation method, and a method for the cyclotrimerization of isoprene to produce trimethylcyclododecanetriene. Background Technology
[0002] Isoprene is one of the olefins produced during petrochemical production and is an important organic chemical raw material with a wide range of applications. With the rapid development of science and technology and the continuous progress of low-molecular-weight polymerization technology for olefins, such as trimerization, it is receiving increasing attention. Among these, the trimerization and cyclization of isoprene to form trimethylcyclododecanetriene (TMCDT) has broad application prospects and relatively high industrial value.
[0003] TMCDT is an important intermediate in organic and fine chemicals with special uses. It can be used to synthesize saturated or unsaturated diacids and their derivatives. It is also a raw material for polyesters, polyamides, plasticizers, flame retardants, macrocyclic organic compounds and certain macrocyclic musks, and has a wide range of industrial applications.
[0004] Isoprene cyclopolymerization catalysts are mainly homogeneous catalysts, and their main problem is the low selectivity of the trimerized target product TMCDT. Summary of the Invention
[0005] To address the above problems, heterogeneous catalysts are a better choice. The purpose of this invention is to provide a heterogeneous catalyst that differs from the prior art, and to provide its preparation method and a method for the cyclotrimerization of isoprene to produce trimethylcyclododecanetriene.
[0006] Biomass carbon material (BIOC) is a nanomaterial with a rich porous structure and a large specific surface area, produced by high-temperature calcination of biomass under anaerobic or oxygen-deficient conditions. The inventors discovered that using a catalyst obtained by loading nickel compounds onto BIOC and mixing it with alkyl aluminum chloride to catalyze the cyclization polymerization of isoprene exhibits high selectivity for the trimer target product TMCDT and low levels of C16 and higher byproducts. Based on this, the present invention was developed.
[0007] To achieve the above objectives, 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 and reacting biomass carbon material BIOC, nickel acetylacetonate, and alkyl aluminum chloride with an optional solvent, and recovering the product to obtain a carbon-based nickel-containing catalyst.
[0008] More specifically, the method for preparing carbon-based nickel-containing catalysts provided by the present invention includes the following steps: under anhydrous and oxygen-free reaction conditions and nitrogen protection, the biomass carbon material BIOC, nickel acetylacetonate, alkyl aluminum chloride, and optional light aromatic solvent are mixed and stirred at 30-60°C for 5-30 hours, and the optional recovered product is used to obtain the carbon-based nickel-containing catalyst.
[0009] In this invention, the biomass carbon material BIOC contains not only carbon but also a small amount of oxygen. Based on the total weight of the BIOC, the carbon content is 85-99.9% by weight, with the remainder primarily being oxygen. Preferably, the biomass carbon material BIOC may also contain nitrogen in addition to carbon and oxygen. Based on the total weight of the BIOC, the carbon content is 80-99.9% by weight, the nitrogen content is 0.1-10% by weight, and the remainder is oxygen.
[0010] In this invention, the biomass carbon material BIOC is mainly derived from carbon materials obtained by carbonizing biomass raw materials such as starch, cellulose, and lignin. For example, the biomass raw materials are calcined at 800-1300℃ for 2-10 hours in an oxygen-free atmosphere to obtain the biomass carbon material. Alternatively, the biomass raw materials are calcined at 800-1300℃ for 2-10 hours in an ammonia atmosphere to obtain the biomass carbon material containing nitrogen. The ammonia atmosphere contains ammonia and nitrogen, and the ammonia content is 0.1-10% by volume.
[0011] In this invention, the weight ratio of nickel acetylacetone to biomass carbon material is 2-20, preferably 5-15; the light aromatic hydrocarbon can be selected from benzene, toluene, ethylbenzene, xylene, etc., preferably toluene; the weight ratio of light aromatic hydrocarbon to biomass carbon material is 5-25:1.
[0012] To achieve the above objectives, a second aspect of the present invention provides a catalyst prepared by the above preparation method, which is composed of nickel-loaded biomass carbon material BIOC and 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] To achieve the above objectives, a third aspect of the present invention provides a method for isoprene cyclization trimerization, wherein isoprene is used as a raw material and the reaction occurs at 60-130°C, preferably 80-100°C, in the presence of a catalyst prepared in the first aspect of the present invention or a catalyst provided in the second aspect of the present invention, to obtain trimethylcyclododecanetriene.
[0014] Specifically, the third aspect of this invention provides a method for the cyclization trimerization of isoprene. The reaction is carried out under the protection of an inert gas such as nitrogen. The mass ratio of solvent light aromatic hydrocarbon, isoprene, and catalyst is 10-200:2-100:1. The reaction temperature is 60-130°C, preferably 80-100°C, and the reaction pressure is 0.1-1 MPa. The reaction is carried out for 1-12 hours with stirring. After the reaction is completed, a reaction terminator such as methanol is added to the resulting liquid under the protection of an inert gas such as nitrogen to terminate the reaction. The reaction product is collected by vacuum distillation to obtain the desired fraction.
[0015] In this invention, the alkyl aluminum chloride is preferably sesquiethyl aluminum chloride and / or diethylaluminum chloride, and more preferably sesquiethyl aluminum chloride.
[0016] In this invention, the weight ratio of the alkyl aluminum chloride to the nickel-loaded BIOC biomass carbon material is 1-50, preferably 2-25.
[0017] The isoprene cyclization polymerization method provided by this invention has high selectivity for the trimer target product TMCDT and few C16 and above byproducts in the product. Detailed Implementation
[0018] The present invention will be further illustrated by the following examples, but these examples are not intended to limit the invention.
[0019] Examples 1-4 illustrate the carbon-based nickel-containing catalyst and its preparation method provided by the present invention.
[0020] Example 1
[0021] Under anhydrous and oxygen-free reaction conditions and nitrogen protection, 5g of biomass carbon material BIOC sample A1 (lignin) was calcined and carbonized at 800℃ in an oxygen-free atmosphere for 6 hours, with a specific surface area of 583m². 2 / g, carbon content is 97.1 wt%, nitrogen content is 1.8 wt%, the balance is oxygen, the same below), appropriate amount of nickel acetylacetone, 20g sesquiethylaluminum chloride and 200g toluene are mixed and stirred at 30℃ for 24h to obtain catalyst X1, in which nickel content is 9.8%, biomass carbon material BIOC content is 34.6% and alkylaluminum chloride content is 55.6%.
[0022] Example 2
[0023] Under anhydrous and oxygen-free reaction conditions and nitrogen protection, 6g of biomass carbon material BIOC sample A1, an appropriate amount of nickel acetylacetone, 20g of diethylaluminum chloride and 300g of toluene were mixed and stirred at 40℃ for 18h to obtain catalyst X2, in which the nickel content was 7.7%, the biomass carbon material BIOC content was 35.1% and the alkyl aluminum chloride content was 57.2%.
[0024] Example 3
[0025] The steps are the same as 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 hours under an atmosphere of 2% by volume ammonia, with nitrogen as the equilibrium gas, and the nano-carbon material had a specific surface area of 628 m²) was used. 2 The raw material consists of a carbon content of 93.5% by weight, a nitrogen content of 3.9% by weight, and the balance being oxygen (the same applies below). 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 in Example 2, except that biomass carbon material BIOC sample A2 is used as the raw material. Catalyst X4 is obtained, wherein 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] Examples 5-8
[0029] This embodiment illustrates the isoprene cyclization trimerization method provided by the present invention.
[0030] The reaction was carried out in a 500 mL Parr high-pressure reactor. The air in the reactor was first purged three times with nitrogen. Then, under nitrogen protection, 100 mL of toluene, 10 g of catalysts X1-X4, and 50 g of isoprene were added to the reactor. The reaction was maintained at 85 °C and 0.3 MPa with stirring for 2 hours. After the reaction was completed, methanol was added to the resulting liquid under nitrogen protection to terminate the reaction. The desired fractions were collected by vacuum distillation. The selectivity data for each example were calculated by gas chromatography analysis:
[0031] With X1 as the catalyst, the selectivity of TMCDT is 83.4%, and the selectivity of C16 and above byproducts is 6.5%.
[0032] With X2 as the catalyst, the selectivity of TMCDT is 80.9%, and the selectivity of C16 and above byproducts is 7.4%.
[0033] With X3 as the catalyst, the selectivity of TMCDT is 89.1%, and the selectivity of C16 and above byproducts is 3.9%.
[0034] With X4 as the catalyst, the selectivity of TMCDT is 88.6%, and the selectivity of C16 and above byproducts is 4.1%.
[0035] Example 9
[0036] The reaction was carried out in a 500 mL Parr high-pressure reactor. The air in the reactor was first purged three times with nitrogen. Then, under nitrogen protection, 100 mL of toluene, 2 g of catalyst X1, and 50 g of isoprene were added to the reactor. The reaction was maintained at 65 °C and 0.5 MPa with stirring for 6 hours. After the reaction was completed, methanol was added to the resulting liquid under nitrogen protection to terminate the reaction. The desired fraction was collected by vacuum distillation. Gas chromatography analysis of the fraction showed a selectivity of 86.2% for TMCDT and 5.9% for C16 and higher byproducts.
[0037] Example 10
[0038] The reaction was carried out in a 500 mL Parr high-pressure reactor. The air in the reactor was first purged three times with nitrogen. Then, under nitrogen protection, 100 mL of toluene, 5 g of catalyst X1, and 20 g of isoprene were added to the reactor. The reaction was maintained at 105 °C and 0.2 MPa with stirring for 4 hours. After the reaction was completed, methanol was added to the resulting liquid under nitrogen protection to terminate the reaction. The desired fraction was collected by vacuum distillation. Gas chromatography analysis of the fraction showed a selectivity of 73.4% for TMCDT and 13.7% for C16 and higher byproducts.
[0039] Comparative Example 1
[0040] The catalyst was prepared according to the method in Example 1, using activated carbon (commercially purchased from Sinopharm Group, analytical grade, C content greater than 99.0%, ash content less than 1.0%, specific surface area 962 m²). 2 / g) replaced 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 according to the method of Example 5, except that the same mass of D1 was used instead of X1. Gas chromatography analysis of the fraction showed that the selectivity of the catalyst for TMCDT was 51.3%, and the selectivity for C16 and above byproducts was 40.6%.
Claims
1. A carbon-based nickel-containing catalyst for the cyclization trimerization of isoprene, characterized in that, The catalyst is composed of nickel-supported biomass carbon material BIOC and alkyl aluminum chloride. By mass, the nickel content is 7.5-9.8%, the BIOC content is 31.3-39.6%, and the alkyl aluminum chloride content is 52.9-59.5%. The catalyst is obtained by mixing and reacting the biomass carbon material BIOC, nickel acetylacetone, and alkyl aluminum chloride with optional solvents, and then recovering the products. 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.
2. The catalyst according to claim 1, characterized in that, The weight ratio of nickel acetylacetonate to biomass carbon material BIOC is 2-20.
3. The catalyst according to claim 2, characterized in that, The weight ratio of nickel acetylacetonate to BIOC biomass carbon material is 5-15.
4. The catalyst according to claim 1, characterized in that, The optional solvent is a light aromatic hydrocarbon, selected from benzene, toluene, ethylbenzene, and xylene.
5. The catalyst according to claim 1, characterized in that, The optional solvent to be added is toluene.
6. The catalyst according to claim 1, characterized in that, The alkyl aluminum chloride is sesquiethyl aluminum chloride and / or diethylaluminum chloride.
7. A method for isoprene cyclization trimerization, characterized in that, This method uses isoprene as a raw material and reacts it in the presence of a carbon-based nickel-containing catalyst according to any one of claims 1-6 at 60-130°C to obtain trimethylcyclododecanetriene.