Catalyst for addition reaction of double-bond compound and acetonitrile, preparation method of catalyst and method for preparing adiponitrile by using catalyst

Abstract

The invention discloses a catalyst for an addition reaction of a double-bond compound and acetonitrile, a preparation method of the catalyst and a method for preparing adiponitrile under catalysis of the catalyst. The catalyst comprises a composite carrier, a main catalyst component, a co-catalyst component and a free radical generator. According to the invention, the reactive hydrogen generator is introduced, and a Lewis acid composite carrier with firmer loading is prepared in a kneading manner, so that the fixed bed catalyst for the addition reaction of double bonds and acetonitrile free radicals is obtained. The strength of the carrier is improved by utilizing the strong coordination effect of the electron-deficient Lewis acid and the electron-rich reactive hydrogen generator, and the loss rate of the active components on the surface of the catalyst loaded with the active metal is obviously reduced, so that the one-way service life of the catalyst is prolonged, and the service time is prolonged. According to the catalyst and the material formula provided by the invention, one-step preparation of 1, 6-ADN from ethylene by a fixed bed is realized, the utilization rate of active components is high, the byproducts of succinonitrile and n-octanedinitrile are produced, and the catalyst and the material formula have relatively high industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, in particular to a catalyst for the addition reaction of a double bond compound and acetonitrile, a preparation method thereof, and a method for catalytically preparing adiponitrile by using the catalyst. Background Art

[0002] As one of the upstream raw materials of nylon 66, due to the technical blockade of adiponitrile production in my country by foreign companies, my country's nylon 66 industry has not been able to form a complete industrial system, which has restricted the rapid development of the domestic industry.

[0003] The adiponitrile (ADN) industry faces high financial and technological barriers to entry. Global ADN producers are primarily INVISTA, Ascend, BASF, Asahi Kasei, and Huafeng. ADN production capacity is highly concentrated in the global market, with INVISTA, BASF, and Ascend accounting for a combined 94% of the total capacity, creating a clear monopoly. According to research, global ADN production capacity reached 1.901 million tons / year in 2019, of which only INVISTA sells ADN externally; the other companies produce and sell the product internally.

[0004] The main adiponitrile production processes include: acrylonitrile electrolytic dimerization, adipic acid amination, direct butadiene hydrocyanation, and the caprolactam process. The acrylonitrile process for producing adiponitrile was first successfully developed by Monsanto. However, the reaction consumes a large amount of electricity, and reaction conditions such as acrylonitrile concentration, electrolyte pH, current density, and electrolyte flow rate significantly affect reaction selectivity and yield, making effective control difficult.

[0005] Representative adipic acid amination processes include the BASF gas phase process, the Monsanto gas phase process, and the Rhone-Poulenc liquid phase process. This process is typically divided into two main production processes: the liquid phase process and the gas phase process. The liquid phase process has a longer history, but suffers from poor product quality and a low yield of approximately 84-93%. The gas phase process, further divided into the BASF process and the Monsanto process, offers significantly improved product quality and yield compared to the liquid phase process, reaching yields of 92-96%. However, the complex process and low yield of adipic acid production have led to high adipic acid prices and, consequently, high adiponitrile costs. Consequently, DuPont, Asahi Kasei, BASF, and PetroChina Liaoyang Branch have all ceased production.

[0006] The direct cyanidation of butadiene to produce adiponitrile was successfully developed by DuPont in the United States in the 1970s. In 2004, Koch Industries (KOCH) acquired DuPont's Textiles & Interiors division to form INVISTA, which in turn acquired the direct cyanidation of butadiene to produce adiponitrile. Due to the advanced technology and the long-standing availability of nylon 66 in developed countries, companies such as Asahi Kasei (Japan), Rhodia (France), and BASF (Germany) have all developed their own proprietary direct cyanidation of butadiene to produce adiponitrile. This process involves three steps: hydrocyanation in the first step, isomerization, and hydrocyanation in the second step. The new technology has selectively retained the first and second steps. Patent CN101918356A discloses a bidentate ligand catalyst for the direct cyanation of butadiene to produce ADN, and Patent CN105017073A discloses a catalyst application method for the direct cyanation of butadiene to produce ADN, as shown in Reaction Scheme A below. However, the current technology for producing ADN from butadiene is tightly controlled, with strict requirements for reaction selectivity, resulting in low equipment efficiency in various plants.

[0007]

[0008] Existing ADN production systems suffer from low operational efficiency, complex and cumbersome operations, stringent selectivity requirements, difficulty in resolving certain setbacks, poor operational stability, and severe equipment corrosion. Therefore, it is necessary to develop a simple and efficient engineering route for ADN production. Summary of the Invention

[0009] In view of the above problems existing in the prior art, one of the objects of the present invention is to provide a highly stable catalyst for preparing dinitrile by the addition reaction of a double bond compound with acetonitrile.

[0010] A second object of the present invention is to provide a method for preparing the catalyst.

[0011] A third object of the present invention is to provide a method for preparing 1,6-adiponitrile (ADN) by catalyzing the addition reaction of acetonitrile using the catalyst.

[0012] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0013] In a first aspect, the present invention provides a catalyst for the addition reaction of a double bond compound with acetonitrile, the catalyst comprising a composite support, a main catalyst component, a co-catalyst component and a free radical generator;

[0014] Based on the total weight of the catalyst, the content of the composite carrier is 30 to 89 wt%, preferably 45 to 80 wt%;

[0015] Based on the total weight of the catalyst, the main catalyst component, calculated as nickel oxide, has a content of 4 to 40 wt%, preferably 5 to 24 wt%;

[0016] Based on the total weight of the catalyst, the content of the promoter component, calculated as metal oxide, is 0.0005 to 20 wt%, preferably 0.001 to 15 wt%;

[0017] Based on the total weight of the catalyst, the content of the free radical generator is 0.0002 to 20 wt%, preferably 0.002 to 15 wt%;

[0018] The carrier comprises: Lewis acid carrier raw powder and active hydrogen generator, and the mass ratio of Lewis acid carrier raw powder to active hydrogen generator is 99.5-40:60-0.5;

[0019] Preferably, the precursor of the main catalyst component is selected from one or more of nickel powder, nickel wire, nickel oxide, nickel chloride, nickel selenide, nickel sulfide, nickel acetate, bis(1,5-cyclooctadiene) nickel and nickel hydroxide.

[0020] Preferably, the precursor of the co-catalyst component is selected from one or more of nitrates, carbonates, chlorides, acetates, acetylacetonates and organometallic compounds of at least one of metals Zr, Zn, Al and Sn.

[0021] Preferably, the precursor of the free radical generator is selected from: ammonium cerium nitrate, 2,2,6,6-tetramethylpiperidine-nitrogen-oxide, and azobisisobutyronitrile.

[0022] Preferably, the Lewis acid carrier raw powder is selected from one or more of: activated alumina, aluminum silicate, magnesium aluminum silicate, zinc oxide, zirconium oxide, aluminum nitrate and zirconium nitrate.

[0023] Preferably, the precursor of the active hydrogen generator is selected from at least one or more of silica gel with a pore size of 2 to 1000 nm, fumed silica, silica sol, diatomaceous earth, kaolin, silica sol (solid content 2 to 60%), boric acid, boron oxide, titanium oxide, titanate, titanium dioxide, metaaluminic acid, silicotungstic acid, boron nitride, and zirconium acetylacetonate.

[0024] Preferably, the pore volume of the catalyst is 0.3-1.4 mL / g, the average pore diameter is 16-40 nm, and the total pore volume is 0.3-1.4 cm3 as measured by liquid nitrogen adsorption and mercury porosimetry. 3 / g.

[0025] In a second aspect, the present invention provides a method for preparing the catalyst, comprising the following steps:

[0026] 1) kneading Lewis acid carrier raw powder, active hydrogen generator precursor, solvent and sesbania powder according to proportion to obtain a composite carrier wet material; then shaping, drying and calcining the composite carrier wet material to obtain a composite carrier;

[0027] 2) preparing a mixed solution of a precursor of the main catalyst component and a precursor of the co-catalyst component, and then impregnating the composite support obtained in step 1) in the mixed solution for 8-24 hours, and then drying the impregnated material at 80-150° C. for 1-6 hours to obtain a dry catalyst precursor;

[0028] 3) impregnating the catalyst precursor obtained in step 2) in a solution of a free radical generator precursor for 8-24 hours at a vacuum degree of 0.09 MPa, and then drying the impregnated material at 80-150° C. for 1-6 hours;

[0029] 4) calcining the product obtained in step 3) for 2-5 hours at a temperature of 300-600° C., and then cooling naturally to obtain a catalyst.

[0030] Preferably, the solvent in step 1) is selected from water, DMSO, DMF, acetic acid, methanol, THF, ethyl acetate, petroleum ether, etc.

[0031] Based on the total weight of the catalyst, the content of the sesbania powder is 1 to 10 wt%, preferably 2 to 6 wt%.

[0032] Preferably, the active hydrogen generating agent in step 1) is selected from a powder with a pore size of 2 to 1000 nm or a suspension containing the powder component or a corresponding compound solution, such as silica gel, fumed silica, silica sol, diatomaceous earth, kaolin, silica sol (solid content 2 to 60%), boric acid, boron oxide, titanium oxide, titanate, titanium dioxide, metaaluminate, silicotungstic acid, boron nitride or a solution thereof, an aqueous solution of aluminum nitrate, an ethanol solution of zirconium acetylacetonate, etc.

[0033] In the suspension containing powdered particles, the compound particles preferably have a pore size of 3 to 500 nm.

[0034] The silica sol includes ammonium silica sol, hydrogen silica sol, sodium silica sol, cesium silica sol and the like.

[0035] The boric acid can be added in solid form for blending and kneading, or can be added in the form of a boric acid aqueous solution, a boric acid acetic acid solution, or a boric acid or formic acid solution.

[0036] The boron oxide can be added in solid form or dissolved in water, alcohol or acetic acid.

[0037] Preferably, the drying temperature in step 1) is 60-140° C., and the drying time is 1-6 hours, preferably 1-4 hours.

[0038] Preferably, the impregnation in step 2) is vacuum impregnation or atmospheric pressure impregnation, preferably vacuum impregnation, with a vacuum degree of 0.01-0.1 MPa, preferably 0.03-0.09 MPa, and a vacuum impregnation time of 0.1-6 h, preferably 0.2-3 h.

[0039] Preferably, the calcination temperature in step 4) is 400-600°C, preferably 430-580°C.

[0040] In a third aspect, the present invention provides a method for preparing 1,6-adiponitrile (AND) by catalyzing the addition reaction of acetonitrile using the catalyst, which is represented by the following reaction formula 1 and is carried out as follows:

[0041]

[0042] The catalyst is placed in a fixed bed reactor, raw material ethylene is fed through a gas line, and acetonitrile is fed into the reactor through a micro-metering pump, and the reaction product is analyzed by gas chromatography.

[0043] Preferably, the molar ratio of acetonitrile:ethylene is 1:5 to 10:1, and the water content in acetonitrile is 0.1%-0.5%.

[0044] Preferably, 10 g of catalyst is loaded into a fixed bed tube with an inner diameter of 18 mm and a length of 59 cm. Quartz sand is filled at both ends to keep the catalyst in the constant temperature zone of the electric furnace. The acetonitrile liquid feed pump is 0.1-4.3 ml / min, and the ethylene gas flow rate is 42.5 ml / min-9.15 L / min. The mass space velocity when feeding the liquid is 0.5-20 h -1 , the reaction temperature is 50-180℃ and the pressure is 0.1-1MPa.

[0045] Liquid hourly mass space velocity refers to the total mass of the raw material ethylene and acetonitrile mixed reactants processed by unit mass of catalyst per hour.

[0046] According to the above specific parameters, a catalyst with good active center distribution and reaction performance can be prepared, and the strength and service life of the catalyst can be guaranteed.

[0047] Beneficial effects:

[0048] 1. The present invention introduces an active hydrogen generator to prepare a Lewis acid composite carrier with a stronger load by kneading, thereby obtaining a fixed-bed catalyst for the free radical addition reaction of double bonds with acetonitrile. The strong coordination effect between the electron-deficient Lewis acid and the electron-rich active hydrogen generator is utilized to increase the carrier strength, and the loss rate of active components on the catalyst surface after loading the active metal is significantly reduced, thereby increasing the catalyst's single-pass service life and extending its service life. The catalyst and material formulation provided by the present invention achieve a one-step fixed-bed preparation of 1,6-ADN from ethylene, with high active component utilization and the production of succinonitrile and n-octanedinitrile as byproducts, thus having high industrial application value.

[0049] 2. The catalyst of the present invention has a simple preparation process, low cost, and the active components can be efficiently utilized. It has high reactivity and stability, and the catalyst service life is more than 1000 hours. DETAILED DESCRIPTION

[0050] The present invention will be described in detail below. Before describing, it should be understood that the terms used in this specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted according to the meaning and concept corresponding to the technical aspects of the present invention on the basis of the principle that allows the inventor to appropriately define the terms for the best interpretation. Therefore, the descriptions presented here are merely preferred examples for illustrative purposes and are not intended to limit the scope of the present invention. It should be understood that other equivalents or improvements can be obtained therefrom without departing from the spirit and scope of the present invention.

[0051] As used herein, the terms "comprises," "includes," "has," "contains" or any other similar terms are open conjunctions that are intended to cover non-exclusive inclusions. For example, a composition or article containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or article. In addition, unless expressly stated to the contrary, the term "or" refers to an inclusive "or" rather than an exclusive "or." For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). In addition, as used herein, the terms "comprises," "includes," "has," and "contains" should be interpreted as specifically disclosed and simultaneously cover closed or semi-closed conjunctions such as "consisting of" and "consisting essentially of."

[0052] Throughout this document, all features or conditions defined as numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible subranges and individual values within those ranges, particularly integer values. For example, a description of a range "1 to 8" should be considered to specifically disclose all possible subranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, and so forth, particularly those defined by all integer values, and should be considered to specifically disclose individual values within those ranges such as 1, 2, 3, 4, 5, 6, 7, and 8. Unless otherwise indicated, the foregoing interpretation applies to all of the present disclosure, regardless of whether the ranges are comprehensive or not.

[0053] If a quantity or other value or parameter is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that all ranges consisting of any upper limit or preferred value of the range and any lower limit or preferred value of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, when a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0054] In this document, numerical values should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range from 39.50 to 40.49.

[0055] According to the preparation method of the catalyst of the present invention, the active hydrogen generator precursor is added when preparing the carrier, and it is fully and evenly distributed in contact with the surface of the Lewis acid carrier, kneading is formed, and the active hydrogen generator is adhered to the surface of the Lewis acid carrier raw powder in solid form or single molecule or ion dissolved state, and the active hydrogen additive forms a node, so that the link between the carrier molecular groups is more solid. In the preparation method of the catalyst of the present invention, a variety of organic substances are added during the preparation process, such as sesbania powder, 2,2,6,6-tetramethylpiperidine-nitrogen-oxide or azobisisobutyronitrile as a precursor of a free radical generator, but after the final calcination process, the organic matter is burned, but the relevant charge properties are retained, which is also the key to the catalyst of the present invention being able to achieve related functions. For example, the negatively charged catalyst precursor is also negatively charged after calcination, and the catalyst precursor with free radicals is also free radicals after calcination, which will cause the reaction initiation effect that the free radicals should have.

[0056] Unless otherwise specified, the raw materials, reagents, and methods used in the examples are all conventional in the art. The raw materials are as follows:

[0057] Raw material name Specification supplier Nickel nitrate AR (Shanghai test), ≥98.0% Sinopharm Nickel acetate, tetrahydrate 99.0％ Maclean Zirconium acetylacetonate 98％ Maclean Silica Sol 30％ Qingdao Grid γ-alumina 99.99％ Maclean Gas Silicon 30％ Qingdao Grid Boric acid ≥99.5 Maclean Sesbania powder KF-25 Taobao Cerium ammonium nitrate 99.0％ Maclean 2,2,6,6-Tetramethylpiperidin-1-oxyl free radical 98％ Maclean Zinc propionate 97％ Maclean

[0058] Example

[0059] Example 1

[0060] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0061] Catalyst preparation: Weigh 137g of nickel acetate tetrahydrate and 1g of cerium ammonium nitrate and dissolve them in 500ml of deionized water. After sufficient dissolution, vacuum impregnate the composite support at a vacuum degree of 0.09MPa and let it stand for 16h. Dry the impregnated material at 110°C for 2h to obtain a dry catalyst precursor. Weigh 1g of zirconium acetylacetonate and dissolve it in 300ml of methanol. Impregnate the dried catalyst precursor and let it stand for 16h. Dry the impregnated material at 110°C for 2h and then calcine it. The calcination procedure takes 3.5h to raise the temperature to 500°C, maintain at 500°C for 3h, and then cool it naturally to obtain the catalyst.

[0062] The elemental composition detected by ICP spectrometer was: Ni (5.1 wt%), Zr (0.029 wt%), Ce (0.040 wt%).

[0063] Example 2

[0064] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0065] Catalyst Preparation: Weigh 137g of nickel acetate tetrahydrate and dissolve it in 500ml of deionized water. Once fully dissolved, vacuum impregnate the composite support at a vacuum of 0.09MPa and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours to obtain a dry catalyst precursor. Weigh 1g of zirconium acetylacetonate and 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical and dissolve them in 300ml of methanol. Impregnate the dried catalyst precursor and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours and then calcine it. The calcination procedure takes 3.5 hours to raise the temperature to 500°C, maintain it at 500°C for 3 hours, and then cool it naturally to obtain the catalyst. The elemental composition determined by ICP spectrometry is: Ni (5.2wt%), Zr (0.030wt%).

[0066] Example 3

[0067] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0068] Catalyst Preparation: Weigh 137g of nickel acetate tetrahydrate and dissolve it in 500ml of deionized water. Once fully dissolved, vacuum impregnate the composite support at 0.09MPa and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours to obtain a dry catalyst precursor. Weigh 1g of zirconium acetylacetonate, 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl radical, and 1g of azobisisobutyronitrile (AIBN) and dissolve them in 300ml of acetonitrile. Impregnate the dried catalyst precursor and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours and then calcine it. The calcination procedure takes 3.5 hours to rise to 500°C, maintain at 500°C for 3 hours, and then cool naturally to obtain the catalyst. The elemental composition determined by ICP spectrometry is: Ni (5.1wt%), Zr (0.030wt%).

[0069] Example 4

[0070] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0071] Catalyst Preparation: 137g of nickel acetate tetrahydrate and 1g of zirconium nitrate pentahydrate were dissolved in 500ml of deionized water. Once fully dissolved, the composite support was vacuum impregnated at 0.09 MPa and allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours to obtain a dry catalyst precursor. 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl radical and 1g of azobisisobutyronitrile (AIBN) were dissolved in 300ml of acetonitrile and impregnated with the dried catalyst precursor. The product was allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours and then calcined. The calcination procedure took 3.5 hours to reach 500°C, then maintained at 500°C for 3 hours, and then cooled naturally to obtain the catalyst. The elemental composition determined by ICP spectroscopy was: Ni (5.2 wt%), Zr (0.033 wt%).

[0072] Example 5

[0073] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0074] Catalyst Preparation: 137g of nickel acetate tetrahydrate and 1g of zinc propionate were dissolved in 500ml of deionized water. Once fully dissolved, the composite support was vacuum impregnated at 0.09MPa and allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours to obtain a dry catalyst precursor. 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl radical and 1g of azobisisobutyronitrile (AIBN) were dissolved in 300ml of acetonitrile and impregnated with the dried catalyst precursor. The product was allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours and then calcined. The calcination procedure took 3.5 hours to raise the temperature to 500°C, then maintained at 500°C for 3 hours, and then cooled naturally to obtain the catalyst. The elemental composition determined by ICP spectroscopy was: Ni (5.3wt%), Zn (0.048wt%).

[0075] Comparative Example 1

[0076] Support preparation: Weigh 500g of γ-alumina powder, 10g of sesbania powder, and 50g of deionized water and stir in a kneader for 30 minutes. Shape the wet support into a 2mm diameter clover leaf shape, dry it in an oven at 120°C for 1 hour, and calcine it at 500°C for 4 hours to obtain a composite support.

[0077] Catalyst Preparation: 137g of nickel acetate tetrahydrate and 1g of zinc propionate were dissolved in 500ml of deionized water. Once fully dissolved, the composite support was vacuum impregnated at 0.09MPa and allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours to obtain a dry catalyst precursor. 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl radical and 1g of azobisisobutyronitrile (AIBN) were dissolved in 300ml of acetonitrile and impregnated with the dried catalyst precursor. The product was allowed to stand for 16 hours. The impregnated product was dried at 110°C for 2 hours and then calcined. The calcination procedure took 3.5 hours to raise the temperature to 500°C, then maintained at 500°C for 3 hours, and then cooled naturally to obtain the catalyst. The elemental composition determined by ICP spectroscopy was: Ni (5.3wt%), Zn (0.048wt%).

[0078] Comparative Example 2

[0079] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0080] Catalyst Preparation: 137 g of nickel acetate tetrahydrate and 1 g of zinc propionate were weighed and dissolved in 500 ml of deionized water. Once fully dissolved, the composite support was vacuum impregnated at 0.09 MPa and allowed to stand for 16 hours. The impregnated material was dried at 110°C for 2 hours to obtain a dry catalyst precursor. The catalyst was then calcined by heating to 500°C over 3.5 hours, maintaining at 500°C for 3 hours, and then cooling naturally to obtain the catalyst. The elemental composition, as determined by ICP spectroscopy, was: Ni (5.3 wt%), Zn (0.047 wt%).

[0081] Comparative Example 3

[0082] Support Preparation: 500g of γ-alumina powder and 10g of silica fume were weighed and stirred in a kneader for 10 minutes. 100g of 30% silica sol, 10g of sesbania powder, and 50g of deionized water were added and kneaded for an additional 20 minutes. The wet support was formed into a 2mm diameter clover leaf shape, dried in an oven at 120°C for 1 hour, and calcined at 500°C for 4 hours to obtain a composite support.

[0083] Catalyst Preparation: Weigh 137g of nickel acetate tetrahydrate and dissolve it in 500ml of deionized water. Once fully dissolved, vacuum impregnate the composite support at a vacuum of 0.09MPa and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours to obtain a dry catalyst precursor. Weigh 1g of 2,2,6,6-tetramethylpiperidin-1-oxyl radical and 1g of azobisisobutyronitrile (AIBN) and dissolve them in 300ml of acetonitrile. Impregnate the dried catalyst precursor and allow to stand for 16 hours. Dry the impregnated material at 110°C for 2 hours and then calcine it. The calcination procedure takes 3.5 hours to raise the temperature to 500°C, maintain it at 500°C for 3 hours, and then cool it naturally to obtain the catalyst. The elemental composition determined by ICP spectrometry is: Ni (5.3wt%), Zn (0.048wt%).

[0084] Test Example 1

[0085] The reaction performance of the fixed bed reactor was tested for the above catalyst, with a catalyst loading of 10 g. The outflow product after 35-40 hours was analyzed. The raw material ethylene was fed through the gas line, and acetonitrile was fed into the fixed bed reactor through a micro-metering pump, and the reaction product was analyzed by gas chromatography. The fixed bed reactor was a fixed bed tube with an inner diameter of 18 mm and a length of 59 cm. Quartz sand was filled at both ends to keep the catalyst in a constant temperature zone heated by an electric furnace. The liquid feed pump was 0.1-4.3 ml / min, and the mass space velocity when feeding the liquid was 0.5-20 h -1 The acetonitrile gas flow rate is 42.5 ml / min to 9.15 L / min. The reaction temperature is 50-180°C, the pressure is 0.1-1 MPa, the acetonitrile:ethylene molar ratio is 1:5 to 10:1, and the water content in the acetonitrile is 0.1%-0.5%.

[0086] The test results are shown in Table 1 below.

[0087] Table 1

[0088]

[0089]

[0090] The evaluation data in Table 1 show that the hydrogenation effects of Examples 1 to 5 are significantly better than those of Comparative Examples 1 to 3.

[0091] In Comparative Example 1, the composite support was prepared without the addition of an active hydrogen generator. The catalyst easily pulverized and lost after prolonged use. In Comparative Example 2, compared to Example 1, no free radical generator was added, and the material failed to undergo a free radical addition reaction. In Comparative Example 3, compared to Example 1, no accessory metal was added, resulting in a slow reaction.

[0092] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A catalyst for the addition reaction of a double bond compound with acetonitrile, the catalyst comprising a composite carrier, a main catalyst component, a co-catalyst component and a free radical generator; Based on the total weight of the catalyst, the content of the composite carrier is 30 to 89 wt%, preferably 45 to 80 wt%; Based on the total weight of the catalyst, the main catalyst component, calculated as nickel oxide, has a content of 4 to 40 wt%, preferably 5 to 24 wt%; Based on the total weight of the catalyst, the content of the promoter component, calculated as metal oxide, is 0.0005 to 20 wt%, preferably 0.001 to 15 wt%; Based on the total weight of the catalyst, the content of the free radical generator is 0.0002 to 20 wt%, preferably 0.002 to 15 wt%.

2. The catalyst according to claim 1, characterized in that The carrier comprises: Lewis acid carrier raw powder and active hydrogen generator, and the mass ratio of Lewis acid carrier raw powder to active hydrogen generator is 99.5-40:60-0.5; Preferably, the precursor of the main catalyst component is selected from one or more of nickel powder, nickel wire, nickel oxide, nickel chloride, nickel selenide, nickel sulfide, nickel acetate, bis(1,5-cyclooctadiene) nickel and nickel hydroxide; Preferably, the precursor of the co-catalyst component is selected from one or more of the following: nitrates, carbonates, chlorides, acetates, acetylacetonates and organometallic compounds of at least one of the metals Zr, Zn, Al and Sn; Preferably, the precursor of the free radical generator is selected from: ammonium cerium nitrate, 2,2,6,6-tetramethylpiperidine-nitrogen-oxide, azobisisobutyronitrile; Preferably, the Lewis acid carrier raw powder is selected from one or more of: activated alumina, aluminum silicate, magnesium aluminum silicate, zinc oxide, zirconium oxide, aluminum nitrate and zirconium nitrate; Preferably, the precursor of the active hydrogen generator is selected from at least one or more of silica gel with a pore size of 2 to 1000 nm, fumed silica, silica sol, diatomaceous earth, kaolin, silica sol (solid content 2 to 60%), boric acid, boron oxide, titanium oxide, titanate, titanium dioxide, metaaluminic acid, silicotungstic acid, boron nitride, and zirconium acetylacetonate.

3. The catalyst according to claim 1, characterized in that Preferably, the pore volume of the catalyst is 0.3-1.4 mL / g, the average pore diameter is 16-40 nm, and the total pore volume is 0.3-1.4 cm3 as measured by liquid nitrogen adsorption and mercury porosimetry. 3 / g.

4. The method for preparing the catalyst according to any one of claims 1 to 3, comprising the steps of: 1) kneading Lewis acid carrier raw powder, active hydrogen generator precursor, solvent and sesbania powder according to proportion to obtain a composite carrier wet material; then shaping, drying and calcining the composite carrier wet material to obtain a composite carrier; 2) preparing a mixed solution of a precursor of the main catalyst component and a precursor of the co-catalyst component, and then impregnating the composite support obtained in step 1) in the mixed solution for 8-24 hours, and then drying the impregnated material at 80-150° C. for 1-6 hours to obtain a dry catalyst precursor; 3) impregnating the catalyst precursor obtained in step 2) in a solution of a free radical generator precursor for 8-24 hours at a vacuum degree of 0.09 MPa, and then drying the impregnated material at 80-150° C. for 1-6 hours; 4) calcining the product obtained in step 3) for 2-5 hours at a temperature of 300-600° C., and then cooling naturally to obtain a catalyst.

5. The method for preparing the catalyst according to claim 4, wherein: Preferably, the solvent in step 1) is selected from water, DMSO, DMF, acetic acid, methanol, THF, ethyl acetate, and petroleum ether; Based on the total weight of the catalyst, the sesbania powder content is 1 to 10 wt%, preferably 2 to 6 wt%; Preferably, the active hydrogen generating agent in step 1) is selected from a powder with a pore size of 2 to 1000 nm or a suspension containing the powder component or a corresponding compound solution, such as silica gel, fumed silica, silica sol, diatomaceous earth, kaolin, silica sol (solid content 2 to 60%), boric acid, boron oxide, titanium oxide, titanate, titanium dioxide, metaaluminate, silicotungstic acid, boron nitride or a solution thereof, an aqueous solution of aluminum nitrate, and an ethanol solution of zirconium acetylacetonate; Wherein, for the suspension containing powdered particles, the compound particles have a pore size preferably ranging from 3 to 500 nm; The silica sol includes ammonium silica sol, hydrogen silica sol, sodium silica sol and cesium silica sol; The boric acid can be added in solid form for blending and kneading, or can be added in the form of a boric acid aqueous solution, a boric acid acetic acid solution, or a boric acid or formic acid solution; The boron oxide can be added in solid form or dissolved in water, alcohol or acetic acid.

6. The method for preparing the catalyst according to claim 5, characterized in that: Preferably, the drying temperature in step 1) is 60-140° C., and the drying time is 1-6 hours, preferably 1-4 hours; Preferably, the impregnation in step 2) is vacuum impregnation or atmospheric pressure impregnation, preferably vacuum impregnation, the vacuum degree is 0.01-0.1 MPa, preferably 0.03-0.09 MPa, and the vacuum impregnation time is 0.1-6 h, preferably 0.2-3 h; Preferably, the calcination temperature in step 4) is 400-600°C, preferably 430-580°C.

7. A method for preparing 1,6-adiponitrile (AND) by catalyzing the addition reaction of acetonitrile using the catalyst according to claims 1 to 3, represented by the following reaction formula 1, and carried out as follows: Reaction 1 The catalyst is placed in a fixed bed reactor, raw material ethylene is fed through a gas line, and acetonitrile is fed into the reactor through a micro-metering pump, and the reaction product is analyzed by gas chromatography.

8. The method for preparing 1,6-adiponitrile (AND) according to claim 7, characterized in that Preferably, the molar ratio of acetonitrile:ethylene is 1:5 to 10:1, and the water content in acetonitrile is 0.1%-0.5%; Preferably, 10 g of catalyst is loaded into a fixed bed tube with an inner diameter of 18 mm and a length of 59 cm, and quartz sand is filled at both ends to keep the catalyst in a constant temperature zone heated by an electric furnace; the acetonitrile liquid feed pump is 0.1-4.3 ml / min, the ethylene gas flow rate is 42.5 ml / min-9.15 L / min, and the mass space velocity when feeding the liquid is 0.5-20 h -1 , the reaction temperature is 50-180℃ and the pressure is 0.1-1MPa.

Images