CN112844433B - A kind of metal-free catalyst for hydrochlorination of acetylene and preparation method thereof - Google Patents

Abstract

The invention relates to a non-metallic catalyst for acetylene hydrochlorination and a preparation method thereof. A method for preparing a non-metallic catalyst for acetylene hydrochlorination, the preparation method is as follows: after adding glucose, amine, and ammonium persulfate into a hydrochloric acid solution, stirring, performing hydrothermal treatment, filtering, washing, drying and calcining to obtain the non-metallic catalyst. A non-metallic catalyst for acetylene hydrochlorination and a preparation method thereof according to the present invention is formed by polymerizing amine and glucose, and the self-polymerization reaction of glucose is inhibited during the polymerization process, thereby obtaining a non-metallic carbon with structure regulation Nitrogen material, the catalyst has high catalyst activity, mild preparation conditions, simple process, short preparation period and low cost, and is suitable for acetylene hydrochlorination reaction.

Description

A kind of metal-free catalyst for hydrochlorination of acetylene and preparation method thereof

technical field

The invention belongs to the field of acetylene hydrochlorination, and in particular relates to a non-metal catalyst for acetylene hydrochlorination and a preparation method thereof.

Background technique

Polyvinyl chloride (PVC) is the first synthetic resin material in China and the second in the world. With electrical insulation, flame retardancy and corrosion resistance, it is widely used in various fields such as construction, infrastructure, packaging, electrical and service industries. China is the world's largest PVC consumer and producer. China's annual PVC production is on the rise, and its annual output accounts for more than half of the world's PVC production. Similarly, China's annual PVC consumption also accounts for one-fifth of the world's total consumption.

Polyvinyl chloride is polymerized from the monomer vinyl chloride (VCM). There are two main industrial processes for the production of VCM, the calcium carbide acetylene method and the ethylene method. On the one hand, VCM can be produced by direct acetylene chlorination, and acetylene is produced through coal-based calcium carbonate; on the other hand, ethylene is chlorinated or oxychlorinated to produce 1,2-dichloroethane (EDC), and EDC is heated to VCM is obtained by dehydrochlorination. Since the petrochemical industry is developed in the western world, VCM production is mainly based on olefin technology. However, my country has the resource characteristics of poor oil, little gas, and relatively rich coal. The use of calcium carbide acetylene to produce polyvinyl chloride is more conducive to alleviating the shortage of oil resources in my country, and plays an important role in reducing the dependence on foreign oil and improving energy security. Therefore, the calcium carbide acetylene method has developed into the mainstream process of my country's PVC industry.

However, mercury consumption and mercury pollution have become bottlenecks restricting the development of calcium carbide polyvinyl chloride industry. It is imminent to become mercury-free in the carbide-based polyvinyl chloride industry. Reduction is the process, and mercury-free is the direction. The development and use of mercury-free catalysts is an important way to fundamentally solve the problem of mercury pollution in the production of polyvinyl chloride by the calcium carbide acetylene process and to realize green manufacturing in the polyvinyl chloride industry.

In view of this, the present invention proposes a non-metallic catalyst for acetylene hydrochlorination and a preparation method thereof.

Contents of the invention

The purpose of the present invention is to provide a kind of preparation method of the non-metallic catalyst that is used for acetylene hydrochlorination reaction, and technique is simple.

In order to achieve the above purpose, the adopted technical scheme is:

A method for preparing a non-metallic catalyst for acetylene hydrochlorination, the preparation method is: after adding glucose, amine, and ammonium persulfate into a hydrochloric acid solution, stirring, performing hydrothermal treatment, filtering, washing, drying and calcining to obtain the non-metallic catalyst.

Further, the amine is one or more of o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine;

The molar concentration of the hydrochloric acid solution is 1mol/L.

Still further, the amine is m-phenylenediamine.

Further, the temperature during the stirring process is 0-60°C, and the time is 0-5h;

The temperature of the hydrothermal treatment is 120-200°C, and the time is 5-20h;

The drying temperature is 80°C, and the drying time is 24 hours;

The calcination temperature is 600-1000° C., and the calcination time is 2 hours.

Still further, the calcination temperature is 800°C.

Further, the molar ratio of amine to glucose is 0.1-0.7:1;

The mol ratio of described amine and ammonium persulfate is 1:0.5-2;

The mass volume ratio of the glucose to the hydrochloric acid solution is 10g:25mL.

Still further, the molar ratio of the amine to glucose is 0.3:1;

The molar ratio of the amine to ammonium persulfate is 1:1.

Further, the washing process uses water and ethanol to wash in sequence.

Another object of the present invention is to provide a non-metallic catalyst for acetylene hydrochlorination, prepared by the above-mentioned preparation method, with low cost and high catalytic activity.

Compared with prior art, the beneficial effect of the present invention is:

1. The catalyst has high catalytic activity and stability.

2. The preparation of the catalyst is simple and the operation is convenient.

3. The preparation cost of the catalyst is low.

Description of drawings

Fig. 1 is the TEM characterization of the C-800 and 0.3mPDA-C-800 catalyst prepared in Example 1 and Comparative Example 1; among the figure, a, b are the TEM characterization of the C-800 catalyst, and c, d are 0.3mPDA-C TEM characterization of -800;

Figure 2 is the long-life characterization of the 0.3mPDA-C-800 catalyst prepared in Example 1.

Detailed ways

In order to further elaborate a kind of non-metallic catalyst for acetylene hydrochlorination of the present invention and preparation method thereof, achieve the expected purpose of the invention, below in conjunction with preferred embodiment, a kind of acetylene hydrochlorination proposed according to the present invention is used The non-metallic catalyst and preparation method thereof, its specific implementation, structure, characteristics and efficacy, are described in detail below. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures or characteristics of one or more embodiments may be combined in any suitable manner.

Below in conjunction with specific embodiment, a kind of metal-free catalyst for acetylene hydrochlorination of the present invention and preparation method thereof are described in further detail:

Technical scheme of the present invention is:

A method for preparing a non-metallic catalyst for acetylene hydrochlorination, the preparation method is: after adding glucose, amine, and ammonium persulfate into a hydrochloric acid solution, stirring, performing hydrothermal treatment, filtering, washing, drying and calcining to obtain the non-metallic catalyst.

The hydrochloric acid solution is acidic and provides an acidic environment for amine and ammonium persulfate, so it can also be an acidic solution such as sulfuric acid solution that does not affect the polymerization reaction.

Preferably, the amine is one or more of o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine;

The molar concentration of the hydrochloric acid solution is 1mol/L.

Further preferably, the amine is m-phenylenediamine.

Preferably, the temperature during the stirring process is 0-60°C, and the time is 0-5h. The stirring process is to ensure that substances such as glucose are mixed evenly, and at the same time, the polymerization products of glucose and amine are limited to a specific molecular weight.

The temperature of the hydrothermal treatment is 120-200°C, and the time is 5-20h;

The drying temperature is 80°C, and the drying time is 24 hours;

The calcination temperature is 600-1000° C., and the calcination time is 2 hours.

Further preferably, the calcination temperature is 800°C.

Preferably, the molar ratio of amine to glucose is 0.1-0.7:1;

The mol ratio of described amine and ammonium persulfate is 1:0.5-2;

The mass volume ratio of the glucose to the hydrochloric acid solution is 10g:25mL.

Further preferably, the molar ratio of the amine to glucose is 0.3:1;

The molar ratio of the amine to ammonium persulfate is 1:1.

Preferably, the washing process uses water and ethanol to wash in sequence.

Example 1:

Operation steps for preparing catalyst:

Add 10g of D-(+)-glucose to 25mL of 1M hydrochloric acid, stir to form a transparent solution, then add m-phenylenediamine and ammonium persulfate in a molar ratio of 1:1 to the clear solution, and the solution is kept at 60°C Stir for 10 min. (The molar ratio of m-phenylenediamine to D-(+)-glucose is 0.3:1)

Then the solution was added into a stainless steel hydrothermal kettle for hydrothermal treatment, kept at 160° C. for 10 h, and then filtered to obtain a sample. After the sample was washed with water and ethanol for 10 h, it was suction filtered, and the sample obtained by suction filtration was placed in an oven and dried at 80° C. for 24 h. Control nitrogen and carbon. Under the atmosphere of inert gas N ₂ , the temperature was raised from room temperature to 800° C. at a rate of 5° C./min, and kept for 2 hours to obtain the non-metallic catalyst. The obtained metal-free catalyst was named 0.3mPDA-C-800.

Take 2mL of the above-mentioned catalyst sample in the acetylene hydrochlorination fixed-bed reaction device, and carry out the acetylene hydrochlorination reaction test. The reaction conditions are: reaction temperature 220°C, GHSV _(C2H2) = 150h ^-1 , HCl/C ₂ H ₂ = 1.15/1. Under the reaction conditions, the conversion rate of vinyl chloride is as high as 96.41%. The product was analyzed by GC-2014C model gas chromatography, FID detector, GDX-301 packed column. At a reaction temperature of 240°C and GHSV _(C2H2) = 30h ^-1 , the life test of the catalyst was carried out. The results are shown in Figure 2. The conversion rate of the catalyst decreased by 12.6% after 260h, which proves that the catalyst has good stability.

Comparative example 1:

Operation steps for preparing catalyst:

Add 10g of D-(+)-glucose into 25mL of 1M hydrochloric acid, stir to form a transparent solution, and then stir at 60°C for 10min. Then the solution was added into a stainless steel hydrothermal kettle for hydrothermal treatment, kept at 160° C. for 10 h, and then filtered to obtain a sample. After the sample was washed with water and ethanol for 10 h, it was suction filtered, and the sample obtained by suction filtration was placed in an oven and dried at 80° C. for 24 h. Under the atmosphere of inert gas N ₂ , the temperature was raised from room temperature to 800°C at a rate of 5°C/min, and kept for 2 hours to obtain a non-metallic catalyst, which was named C-800.

Take 2mL of the above-mentioned catalyst sample in the acetylene hydrochlorination fixed-bed reaction device, and carry out the acetylene hydrochlorination reaction test. The reaction conditions are: reaction temperature 220°C, GHSV _(C2H2) = 150h ^-1 , HCl/C ₂ H ₂ = 1.15/1. Under the reaction conditions, the conversion rate of vinyl chloride was 63.39%. The product was analyzed by GC-2014C model gas chromatography, FID detector, GDX-301 packed column.

The C-800 and 0.3mPDA-C-800 catalysts prepared in Example 1 and Comparative Example 1 were characterized by TEM, and the results are shown in FIG. 1 . In Figure 1, a and b are TEM characterizations of C-800 catalyst, and c and d are TEM characterizations of 0.3mPDA-C-800. It can be seen from Fig. 1 that the microstructure of the catalyst prepared by the technical scheme of the present invention is massive, and compared with the catalyst prepared by the comparative example, it will have more pore structure, which is more conducive to catalyzing the acetylene hydrochlorination reaction, and has better catalytic activity .

Example 2:

The amines used in this embodiment are o-phenylenediamine, m-phenylenediamine and p-phenylenediamine respectively. Other preparations and reaction conditions are the same as in Example 1. The conversion rate of vinyl chloride is shown in Table 1.

Table 1 Effect of different amine species on acetylene hydrochlorination

O-phenylenediamine m-phenylenediamine p-phenylenediamine Vinyl chloride conversion (%) 64.58 96.41 76.41

From the data in Table 1, it can be concluded that the conversion rate of vinyl chloride presents different conversion rates with the addition of different amine species. Among them, the addition of m-phenylenediamine has the most obvious promoting effect on the hydrochlorination of acetylene.

Example 3:

In this example, the molar ratios of phenylenediamine and ammonium persulfate are 1:0.5, 1:1, 1:1.5, and 1:2, respectively. Other preparations and reaction conditions are the same as in Example 1. The conversion rate of vinyl chloride is shown in Table 2.

The impact of table 2 m-phenylenediamine and ammonium persulfate molar ratio on acetylene hydrochlorination

The molar ratio of m-phenylenediamine and ammonium persulfate 1:0.5 1:1 1:1.5 1:2 Vinyl chloride conversion (%) 95.87 96.41 85.38 83.68

From the data in Table 2, it can be concluded that with the increase of ammonium persulfate addition, the conversion rate of vinyl chloride presents a trend of first increasing and then decreasing. Among them, when the ratio of m-phenylenediamine and ammonium persulfate is 1:1, the effect of promoting the hydrochlorination of acetylene is the most obvious.

Example 4:

In this embodiment, the hydrothermal temperature is 120°C, 160°C, and 200°C. Other preparations and reaction conditions are the same as in Example 1. The conversion rate of vinyl chloride is shown in Table 3.

Table 3 The influence of hydrothermal temperature on acetylene hydrochlorination reaction

water temperature 120°C 160°C 200℃ Vinyl chloride conversion (%) 96.98 96.41 96.11

From the data in Table 2, it can be concluded that with the increase of hydrothermal temperature, the conversion rate of vinyl chloride does not show a large fluctuation.

Example 5:

In this embodiment, the hydrothermal time is 5h, 10h, 15h, 20h. Other preparations and reaction conditions are the same as in Example 1. The conversion rate of vinyl chloride is shown in Table 4.

The impact of table 4 hydrothermal time on acetylene hydrochlorination reaction

water heating time 5h 10h 15h 20h Vinyl chloride conversion (%) 95.73 96.92 96.53 95.72

From the data in Table 4, it can be concluded that with the increase of the hydrothermal time, the conversion rate of vinyl chloride does not show large fluctuations.

Embodiment 6:

In this example, under an inert gas N ₂ atmosphere, the temperature was raised from room temperature to different calcination temperatures (600° C., 800° C., 1000° C.) at a heating rate of 5° C./min. Other preparations and reaction conditions are the same as in Example 1. The conversion rate of vinyl chloride is shown in Table 5.

The impact of table 5 calcination temperature on acetylene hydrochlorination reaction

Calcination temperature 600°C 800℃ 1000℃ Vinyl chloride conversion (%) 91.91 96.41 94.82

From the data in Table 5, it can be concluded that with the continuous increase of calcination temperature, the conversion rate of vinyl chloride presents a trend of increasing first and then decreasing. Among them, when the calcination temperature is 800°C, the promotion effect on the hydrochlorination of acetylene is the most obvious.

Embodiment 7:

In this embodiment, the molar ratio x of nitrogen to carbon (m-phenylenediamine: D-(+)-glucose) is controlled to be 0.1, 0.3, 0.5, and 0.7, respectively. Other preparations and reaction conditions are the same as in Example 1. The conversion rates of vinyl chloride at different molar ratios are shown in Table 6.

The impact of table 6 nitrogen-carbon molar ratio on acetylene hydrochlorination reaction

Nitrogen to carbon molar ratio 0.1 0.3 0.5 0.7 Vinyl chloride conversion (%) 78.26 96.41 95.38 90.96

From the data in Table 6, it can be concluded that as the molar ratio of nitrogen to carbon (m-phenylenediamine: D-(+)-glucose) increases, the conversion rate of vinyl chloride shows a trend of first increasing and then decreasing. Among them, when the molar ratio of nitrogen to carbon is 0.3, the promoting effect on the hydrochlorination of acetylene is the most obvious.

The above is only a preferred embodiment of the embodiment of the present invention, and does not limit the embodiment of the present invention in any form. Any simple modification, equivalent change and Modifications still fall within the scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. A preparation method of a non-metal catalyst for acetylene hydrochlorination is characterized by comprising the following steps: adding glucose, amine and ammonium persulfate into a hydrochloric acid solution, stirring, carrying out hydrothermal treatment, filtering, washing, drying and calcining to obtain the nonmetal catalyst;

the molar ratio of the amine to the ammonium persulfate is 1.5-2;

the amine is one or more of m-phenylenediamine and p-phenylenediamine;

the calcination is carried out in a nitrogen atmosphere at a temperature of 600-1000 ℃.

2. The production method according to claim 1,

the molar concentration of the hydrochloric acid solution is 1mol/L.

3. The method according to claim 2,

the amine is m-phenylenediamine.

4. The production method according to claim 1,

the temperature in the stirring process is 0-60 ℃, and the time is 0-5h;

the temperature of the hydrothermal treatment is 120-200 ℃, and the time is 5-20h;

the drying temperature is 80 ℃, and the drying time is 24 hours;

the calcination time is 2h.

5. The production method according to claim 4,

the calcination temperature is 800 ℃.

6. The method according to claim 1,

the molar ratio of the amine to the glucose is 0.1-0.7:1;

the mass volume ratio of the glucose to the hydrochloric acid solution is 10g:25mL.

7. The production method according to claim 6,

the molar ratio of the amine to the glucose is 0.3;

the molar ratio of the amine to the ammonium persulfate is 1.

8. The production method according to claim 1,

the washing process sequentially adopts water and ethanol for washing.

9. A non-metallic catalyst for hydrochlorination of acetylene, characterized in that the non-metallic catalyst is prepared by the method of any one of claims 1 to 8.

Images