CN109225347B

CN109225347B - A kind of acetylene dimerization solid phase catalyst and preparation method and application thereof

Info

Publication number: CN109225347B
Application number: CN201811299993.1A
Authority: CN
Inventors: 代斌; 李聪聪; 谢建伟
Original assignee: Shihezi University
Current assignee: Shihezi University
Priority date: 2018-11-02
Filing date: 2018-11-02
Publication date: 2021-07-30
Anticipated expiration: 2038-11-02
Also published as: CN109225347A

Abstract

The present invention relates to an acetylene dimerization solid-phase catalyst and its preparation method and application. An acetylene dimerization solid-phase catalyst is prepared from the following raw materials: an active component, a cosolvent, a solvent and a catalyst carrier; the active component is cuprous chloride; the cosolvent is aliphatic amine hydrochloric acid Salt, its chemical formula is RNH ₂ ·HCl, R is the C1- _C4 alkyl that contains linear or branched chain; Described solvent is made up of N, N-dimethylformamide and 1,4-dioxane ; Described catalyst carrier coconut shell activated carbon. The invention also discloses the preparation method and application of the catalyst. The acetylene dimerization solid-phase catalyst, preparation method and application thereof of the present invention are solid-phase catalysts, the catalyst dosage is small, the catalyst recycling is convenient, the catalyst activity is high, and the stability is good.

Description

Acetylene dimerization solid-phase catalyst and preparation method and application thereof

Technical Field

The invention belongs to the field of catalysts, and particularly relates to an acetylene dimerization solid-phase catalyst, and a preparation method and application thereof.

Background

Vinyl acetylene, a downstream product of acetylene, is an important fine chemical intermediate, which is widely used in the production of neoprene. Among them, Chloroprene Rubber (CR) is one of seven synthetic rubbers, and is a synthetic polymer material having a wide application prospect in various fields of production and life. Based on the current situation of 'rich coal, lean oil and little gas' in China, an acetylene method (acetylene is dimerized to generate vinyl acetylene, and then the vinyl acetylene reacts with hydrogen chloride to produce chloroprene) is a main route for producing chloroprene rubber in China. Acetylene dimerization reaction to generate vinyl acetylene mainly adopts aqueous phase Nieuwland catalyst and non-aqueous phase Nieuwland catalyst. Through research on acetylene dimerization gas-liquid reaction systems in recent years, the low conversion rate of acetylene and the low selectivity of MVA are the main problems preventing the reaction from developing, and the industrial acetylene conversion per pass is less than 10%, and the MVA selectivity is less than 85%. In addition, in the reaction process, the active component copper is wrapped by the generated high polymer, so that the activity of the catalyst is reduced, and meanwhile, the catalyst is difficult to separate after the reaction, cannot be recycled and can cause pollution to the environment. In addition, in the traditional liquid phase reaction, the addition amount of cuprous chloride and copper chloride is large, the addition amount of the catalyst complex is large and the price is high, and after the liquid phase catalyst is used, high polymer is attached to a reactor, so that equipment is difficult to clean.

In order to overcome the difficulties faced by the traditional gas-liquid reaction, the invention firstly provides an acetylene dimerization gas-solid reaction system, prepares a metal supported catalyst, is applied to acetylene dimerization reaction, and develops a new reaction path for the acetylene dimerization reaction.

Disclosure of Invention

The invention aims to provide an acetylene dimerization solid-phase catalyst which is a catalyst for acetylene dimerization gas-solid reaction and has high activity and good stability.

In order to realize the purpose, the adopted technical scheme is as follows:

an acetylene dimerization solid-phase catalyst is prepared from the following raw materials: active components, cosolvent, solvent and catalyst carrier;

the active component is cuprous chloride;

the cosolvent is fatty amine hydrochloride with chemical formula of RNH₂HCl, R is C1-C containing straight or branched chains₄An alkyl group;

the solvent consists of N, N-dimethylformamide and 1, 4-dioxane;

the catalyst carrier is coconut shell activated carbon.

Further, the molar volume ratio of the active component to the solvent is 1-8 mol: 1-2L;

the mass volume ratio of the cosolvent to the solvent is 200-500 g: 1-2L;

the mass volume ratio of the catalyst carrier to the solvent is 100-500 g: 1-2L;

r of the fatty amine hydrochloride is ethyl.

Further, the active components also comprise: the molar ratio of the copper chloride to the cuprous chloride is 0.3-2: 1-8.

Still further, the volume ratio of the N, N-dimethylformamide to the 1, 4-dioxane is 7: 3;

the molar ratio of the copper chloride to the cuprous chloride is 1: 3.

The invention also aims to provide a preparation method of the acetylene dimerization solid-phase catalyst, which is an impregnation method and has a simple process.

In order to realize the purpose, the adopted technical scheme is as follows:

the preparation method of the acetylene dimerization solid-phase catalyst comprises the following steps:

completely dissolving the cosolvent in a solvent at 70-90 ℃ in an anaerobic environment, and adding the active component to completely dissolve the cosolvent;

then adding a catalyst carrier, stirring at 70-90 ℃ for 100-140min, and stirring at room temperature for 9-11 h;

and finally, carrying out suction filtration and vacuum drying to obtain the acetylene dimerization solid-phase catalyst.

And further, adding copper chloride after the cuprous chloride is completely dissolved, and stirring until the cuprous chloride is dissolved.

Further, adding the catalyst carrier, stirring at 80 ℃ for 120min, and stirring at room temperature for 10 h;

the temperature of the vacuum drying is 70-90 ℃, and the time is 22-26 h.

Further, the temperature of the vacuum drying is 80 ℃, and the time is 24 hours.

The invention also aims to provide application of the acetylene dimerization solid-phase catalyst.

In order to realize the purpose, the adopted technical scheme is as follows:

the application of the catalyst in acetylene dimerization reaction comprises the steps of adding the catalyst into a reactor, introducing acetylene into the reactor, carrying out dimerization reaction on the acetylene to generate vinyl acetylene, wherein the reaction temperature in the reactor is 80-180 ℃, and the acetylene space velocity is 80-140h^-1。

Has the advantages that:

the acetylene dimerization solid-phase catalyst is a solid-phase catalyst, compared with a liquid-phase catalyst, the acetylene dimerization solid-phase catalyst is used for reaction, the catalyst consumption is low, the catalyst is convenient to recycle, and the tube wall of a reactor is convenient to clean, so that the acetylene dimerization solid-phase catalyst is superior to a gas-liquid reaction.

The invention takes coconut shell activated carbon as a catalyst carrier and Cu⁺The catalyst for acetylene dimerization gas-solid reaction is prepared by an impregnation method by taking DMF and 1, 4-dioxane as main active ingredients as a mixed solvent and fatty amine hydrochloride as a cosolvent. Reaction conditions including acetylene airspeed, reaction temperature, active component loading, mixed solvent dosage ratio and the like are screened, and the optimal reaction conditions are finally determined.

The single metal catalyzes the dimerization reaction of acetylene, and the catalyst has quick inactivation and poor stability. The invention compounds the second metal and compounds with copper chloride (CuCl) respectively to carry out the gas-solid reaction of the acetylene dimerization under the double-metal catalysis. Second, the amount of bimetal used was screened.

Drawings

FIG. 1 is a process flow diagram of the catalyst activity testing step in an example of the present invention; in the figure, 1 acetylene, 2 nitrogen, 3 and 4 partial pressure valves, 5 and 6 check valves, 7 and 8 gas filters, 9 and 10 mass flow controllers, 11 fixed bed reactors, 12 aqueous solutions and 13 gas chromatographies are adopted.

Detailed Description

In order to further illustrate the acetylene dimerization solid phase catalyst, the preparation method and the application thereof, and to achieve the intended purpose, the following detailed description will be given to the acetylene dimerization solid phase catalyst, the preparation method and the application thereof, and the specific implementation, the structure, the characteristics and the efficacy thereof according to the present invention. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Before describing the acetylene dimerization solid phase catalyst, the preparation method and the application thereof in detail, it is necessary to further describe the methods mentioned in the invention to achieve better effects.

The process flow diagram of the catalyst activity testing step in the embodiment of the invention is shown in fig. 1, and the specific steps are as follows:

(1) the performance of the catalyst is evaluated by using a stainless steel fixed bed reactor with the inner diameter of 10mm, and the reaction conditions are as follows: raw material acetylene (purity more than 98%), and space velocity of acetylene is 80-140h^-1The reaction temperature is 80-180 ℃.

(2) The gas is fed into a fixed bed reactor (11) through respective one-way check valves (5, 6) and mass flow meters (9, 10), and the loading of the catalyst is 1-5 mL.

(3) The tail gas flows through a gas collecting bottle (12) and enters an Shimadzu GC-2014C type chromatograph (13) for analysis. FID Detector, GDX-301 packed column.

Method for evaluating catalyst

The vinylacetylene-based product obtained in the above example was subjected to composition and content measurement by gas chromatography to calculate the conversion per pass (X) of acetylene_A) And selectivity to vinyl acetylene (S)_MVA)。

The calculation formula of the conversion per pass of acetylene is calculated according to the formula (1):

the calculation formula of the selectivity of the vinyl acetylene is calculated according to the formula (2):

wherein, in the formula (1) and the formula (2)

In the products mainly containing vinyl acetylene obtained in example 1, example 2, example 3, example 4 and comparative example 1The volume percent concentrations of acetylene, acetaldehyde, vinyl acetylene, 2-chloro-1, 3-butadiene (CD), and divinyl acetylene (DVA); considering the volume change of the system before and after the reaction and neglecting the generation of high polymer, the amount of acetylene before the reaction is

The cosolvent in the invention is fatty amine hydrochloride, RNH₂HCl, R is C1-C containing straight or branched chains₄Alkyl, preferably ethyl.

With the above methods and the like in mind, the acetylene dimerization solid phase catalyst, the preparation method and the application thereof according to the invention will be described in further detail with reference to the following specific examples:

the technical scheme is as follows:

the preparation steps of the single metal catalyst in the invention are as follows:

(1) completely dissolving 2-5g of fatty amine hydrochloride into 10-20mL of solvent at 70-90 ℃ in nitrogen atmosphere, and adding 0.01-0.08mol of cuprous chloride to completely dissolve the fatty amine hydrochloride.

The solvent is a mixed solvent of N, N-Dimethylformamide (DMF) and 1, 4-dioxane.

(2) Then adding 1-5g of coconut shell activated carbon, stirring for 100-140min at 70-90 ℃, and then stirring for 9-11h at room temperature.

After the catalyst carrier is added, the catalyst is stirred at a certain temperature and then at room temperature, so that the prepared catalyst has better catalytic effect.

(3) And (3) performing suction filtration, finally performing suction filtration, and performing vacuum drying at the temperature of 70-90 ℃ for 22-26h to obtain the acetylene dimerization solid-phase catalyst, namely the monometallic catalyst for acetylene dimerization gas-solid reaction.

The preparation steps of the bimetallic catalyst in the invention are as follows:

(1) completely dissolving 2-5g of fatty amine hydrochloride into 10-20mL of solvent at 70-90 ℃ in nitrogen atmosphere, adding 0.01-0.08mol of cuprous chloride, adding 0.003-0.02mol of copper chloride after complete dissolution, and stirring until complete dissolution.

In the invention, the active components cuprous chloride and cupric chloride are respectively and sequentially dissolved in the solvent, compared with the method that cuprous chloride and cupric chloride are simultaneously dissolved in the solvent, the sequential dissolution speed is higher, and the catalytic effect of the prepared catalyst is better.

(3) And (3) performing suction filtration, finally performing suction filtration, and performing vacuum drying at the temperature of 70-90 ℃ for 22-26h to obtain the acetylene dimerization solid-phase catalyst, namely the bimetallic catalyst for acetylene dimerization gas-solid reaction.

The specific embodiment is as follows:

example 1.

Single metal catalyst:

(1) after 4g of fatty amine hydrochloride (R is ethyl) was completely dissolved in 15mL of a solvent at 80 ℃ under a nitrogen atmosphere, 0.04mol of cuprous chloride was added to completely dissolve the salt.

(2) Then 3g of coconut shell activated carbon was added, and the mixture was stirred at 80 ℃ for 120min and then at room temperature for 10 hours.

(3) And (3) carrying out suction filtration, finally carrying out suction filtration, and carrying out vacuum drying at 80 ℃ for 24h to obtain the acetylene dimerization solid-phase catalyst, namely a monometallic catalyst for acetylene dimerization gas-solid reaction.

Bimetallic catalyst:

(1) in a nitrogen atmosphere, at 80 ℃, 4g of fatty amine hydrochloride (R is ethyl) is completely dissolved in 15mL of solvent, 0.04mol of cuprous chloride is added, after complete dissolution, 0.01mol of copper chloride is added, and stirring is carried out for 30min to completely dissolve the copper chloride.

(3) And (3) carrying out suction filtration, finally carrying out suction filtration, and carrying out vacuum drying at 80 ℃ for 24h to obtain the acetylene dimerization solid phase catalyst, which is a bimetallic catalyst for acetylene dimerization gas-solid reaction.

Placing the prepared catalyst in a reaction vessel, introducing acetylene, and keeping the space velocity of the acetylene at 80-140h^-1The reaction temperature is 80-180 ℃, and the generated gas is monitored in real time through gas chromatography.

Compared with the conventional liquid catalyst, tests show that the acetylene dimerization solid phase catalyst has better catalytic activity and can catalyze and convert more acetylene with the same amount of catalyst.

Example 2.

This example prepared a bimetallic catalyst. The solvent in this example was DMF, and the other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 1.

Example 3.

This example prepared a bimetallic catalyst. The solvent in this example was 1, 4-dioxane, and the other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 1.

TABLE 1 Effect of different solvents on the gas-solid reaction of acetylene dimerization

As can be seen from the data in table 1, the solvent has an influence on the acetylene dimerization gas-solid reaction, and the influence difference of different solvents on the acetylene dimerization reaction is large, wherein when the solvent is DMF, the promotion effect on the acetylene dimerization gas-solid reaction is the best.

Example 4.

This example prepared a bimetallic catalyst. The volume ratio of the mixed solvent in this example is: v (DMF): v (1, 4-dioxane) ═ 2: other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 2.

Example 5.

This example prepared a bimetallic catalyst. The volume ratio of the mixed solvent in this example is: v (DMF): v (1, 4-dioxane) ═ 5: other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 2.

Example 6.

This example prepared a bimetallic catalyst. The volume ratio of the mixed solvent in this example is: v (DMF): v (1, 4-dioxane) ═ 7:3, other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 2.

Example 7.

This example prepared a bimetallic catalyst. The volume ratio of the mixed solvent in this example is: v (DMF): v (1, 4-dioxane) ═ 8: the other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 2.

TABLE 2 Effect of solvent mixture ratio on acetylene dimerization gas-solid reaction

As can be seen from table 2, in the case of vinylacetylene prepared by catalyzing dimerization of acetylene in example 4, example 5, example 6 and example 7, the volume ratio of the mixed solvent is 7: and 3, the activity of acetylene dimerization gas-solid reaction is obviously higher than that of other proportions, and the highest acetylene yield can reach 42.1 percent.

Example 8.

This example prepared a bimetallic catalyst. The metal precursors in this example are cuprous chloride and anhydrous cupric chloride, respectively, with a bimetallic molar ratio of Cu²⁺：Cu⁺1: 1, other reaction conditions were the same as in example 1. Conversion of acetylene, selectivity to vinyl acetylene and yield of acetyleneSee table 3.

Example 9.

This example prepared a bimetallic catalyst. The metal precursors in this example are cuprous chloride and anhydrous cupric chloride, respectively, with a bimetallic molar ratio of Cu²⁺：Cu⁺1: the other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 3.

Example 10.

This example prepared a bimetallic catalyst. The metal precursors in this example are cuprous chloride and anhydrous cupric chloride, respectively, with a bimetallic molar ratio of Cu²⁺：Cu⁺2:1, other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 3.

Example 11.

This example prepared a bimetallic catalyst. The metal precursors in this example are cuprous chloride and anhydrous cupric chloride, respectively, with a bimetallic molar ratio of Cu²⁺：Cu⁺3: 1, other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 3.

Example 12.

This example prepared a bimetallic catalyst. The metal precursors in this example are cuprous chloride and anhydrous cupric chloride, respectively, with a bimetallic molar ratio of Cu²⁺：Cu⁺4: 1, other reaction conditions were the same as in example 1. The acetylene conversion, the vinylacetylene selectivity and the acetylene yield are shown in Table 3.

TABLE 3 influence of the bimetallic ratio on the acetylene dimerization gas-solid reaction

	Cu²⁺/Cu⁺	Acetylene conversion (%)	Selectivity to vinyl acetylene (%)	Yield of acetylene (%)
					Example 8	1:1	30.7	87.8	27.0
Example 9	1:2	8.80	94.8	8.34
					Example 10	2:1	30.6	90.0	27.5
Example 11	3:1	58.7	86.7	50.9
					Example 12	4:1	39.3	87.9	34.5

As can be seen from Table 3, in examples 8 to 12, when vinylacetylene was produced by the gas-solid reaction of acetylene dimerization, Cu was contained while the total amount of Cu (0.08mol) was kept constant²⁺/Cu⁺Is 3: 1, the selectivity of vinyl acetylene can reach 86.7 percent, the conversion rate of the acetylene can reach 58.7 percent, and the yield of the acetylene is 50.9 percent.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.

Claims

1. an acetylene dimerization solid-phase catalyst, is characterized in that, adopts following raw material to prepare from: active component, cosolvent, solvent and catalyst carrier;

Described active component is cuprous chloride;

Described cosolvent is aliphatic amine hydrochloride, and its chemical formula is RNH ₂ ·HCl, and R is ethyl;

Described solvent is made up of N,N-dimethylformamide and 1,4-dioxane;

Described catalyst carrier coconut shell activated carbon;

Wherein, the molar volume ratio of the active component and the solvent is 1-8mol:1-2L;

The mass volume ratio of the cosolvent to the solvent is 200-500g: 1-2L;

The mass volume ratio of the catalyst carrier to the solvent is 100-500g:1-2L.

2. The acetylene dimerization solid-phase catalyst according to claim 1, wherein,

The active component also includes: cupric chloride, and the molar ratio of the cupric chloride to the cuprous chloride is 0.3-2:1-8.

3. The acetylene dimerization solid-phase catalyst according to claim 2, wherein,

The volume ratio of described N,N-dimethylformamide and 1,4-dioxane is 7:3;

The mol ratio of described cupric chloride and cuprous chloride is 1:3.

4. the preparation method of the acetylene dimerization solid phase catalyst of claim 1, is characterized in that, comprises the following steps:

In an anaerobic environment at 70-90 °C, after the co-solvent is completely dissolved in the solvent, the active component is added to make it completely dissolved;

Then add the catalyst carrier, stir at 70-90°C for 100-140min, and then stir at room temperature for 9-11h;

Finally, suction filtration and vacuum drying to obtain the acetylene dimerization solid-phase catalyst.

5. preparation method according to claim 4, is characterized in that, wherein,

After the cuprous chloride is completely dissolved, cupric chloride is added and stirred until dissolved.

6. preparation method according to claim 4, is characterized in that, wherein,

Add the catalyst carrier, stir at 80°C for 120min, and then stir at room temperature for 10h;

The temperature of the vacuum drying is 70-90°C, and the time is 22-26h.

7. preparation method according to claim 6, is characterized in that, wherein,

The temperature of the vacuum drying is 80°C, and the time is 24h.

8. An acetylene dimerization solid-phase catalyst, characterized in that, the acetylene dimerization solid-phase catalyst is prepared by the preparation method described in any one of claims 4-7.

9. the application of catalyzer in acetylene dimerization, it is characterized in that:

The catalyst according to claim 8 is added to the reactor, then acetylene is introduced into the reactor, and the acetylene undergoes a dimerization reaction to generate vinyl acetylene. The reaction temperature in the reactor is 80-180 ° C, and the acetylene space velocity 80-140h ^-1 .