阅读说明：本技术 一种用于乙炔氢氯化制氯乙烯的非汞催化剂及其制备和使用方法 (Non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene and preparation and use methods thereof ) 是由 高歌 谢永刚 陶萱 陈方永 王吉德 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种用于乙炔氢氯化制氯乙烯的非汞催化剂及其制备和使用方法。该催化剂为含N多孔碳材料催化剂,按摩尔百分比计,其化学组成为：N含量为1-10%,C含量为70-97%,O含量为1-20%,含有少量的Cl,B,F,P或S元素中的一种,其含量<1%,催化剂比表面积为30-3000 m～2/g。与现有技术相比,本发明不使用金属活性组分,制备过程简单,大幅降低无汞催化剂的成本,优势明显。催化剂活性和稳定性均较工业汞催化剂优良,具备大规模投资应用的可能,使用中可以避免催化剂频繁更换,具备工业应用的可操作性。(The invention discloses a non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene and a preparation method and a using method thereof. The catalyst is a N-containing porous carbon material catalyst, and comprises the following chemical components in percentage by mole: n content of 1-10%, C content of 70-97%, O content of 1-20%, and small amount of one of Cl, B, F, P or S<1 percent of catalyst with specific surface area of 30-3000 m 2 (ii) in terms of/g. Compared with the prior art, the method does not use metal active components, has simple preparation process, greatly reduces the cost of the mercury-free catalyst, and has obvious advantages. The catalyst has better activity and stability than industrial mercury catalyst, has possibility of large-scale investment and application, and can be used in the process of preparing the catalystCan avoid frequent replacement of the catalyst and has operability of industrial application.)

1. A non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene is characterized in that: the catalyst is a nitrogen-containing porous carbon material prepared from a nitrogen-containing organic matter precursor and used as an acetylene hydrochlorination catalyst, and the catalyst comprises the following chemical components in percentage by mole: 1-10% of N, 70-97% of C, 1-20% of O, and a small amount of one of Cl, B, F, P or S<1 percent of catalyst with specific surface area of 30-3000 m²/g。

2. The non-mercury catalyst for preparing vinyl chloride through hydrochlorination of acetylene according to claim 1, which is prepared by roasting and molding a nitrogen-containing precursor at high temperature, and storing the nitrogen-containing precursor in vacuum, in a sealed manner or under the protection of nitrogen;

(1) a non-mercury catalyst for the hydrochlorination of acetylene to vinyl chloride according to claim 1 or 2, characterized in that: the nitrogen-containing precursor used for preparing the nitrogen-containing porous carbon material catalyst for acetylene hydrochlorination is one or more of polyaniline, melamine, polypyrrolidone or polyacrylamide;

(2) the nitrogen-containing precursor according to claim 1, wherein the polyaniline is commercially available or prepared by chemical oxidative polymerization, and has an average molecular weight of 3000-100000, and the doping acids used in the process of preparing polyaniline are one or more of hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, boric acid, perchloric acid, hydrofluoric acid or acetic acid; the oxidant is one of ammonium persulfate, potassium dichromate, potassium iodate, ferric trichloride, manganese dioxide, cerium sulfate or hydrogen peroxide, and the raw materials have the following molar ratio: aniline: oxidant =1: 1-5; aniline, doping acid =1: 1-5;

(3) the method for producing a nitrogen-containing precursor according to claim 2, characterized in that: respectively dispersing aniline and oxidant with different doping acids, standing in ice bath for 30 min, slowly and dropwise adding oxidant solution into aniline solution>If not more than 30 min, mixing the solution or one or more of melamine, polyvinylpyrrolidone and polyacrylamide with aniline in a molar ratio of 0.05:0.05:0.05:1-5:5: 1, stirring at 0-80 ℃ for 1.5-10 h at a stirring speed of 100-1000 r/min, filtering, washing the solid product with the used doping acid and distilled water until the filtrate is clear, mixing the solid product or the activating agent, and directly carrying out the subsequent preparation steps or 60-100 h^oC, drying for 6-12 h, or/and 40-60 ^oC, vacuum drying for 6-24 h;

(4) the method for producing a nitrogen-containing precursor according to claim 3, wherein: the activating agent used before drying is saturated liquid of potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, zinc chloride or phosphoric acid, and is uniformly mixed according to the molar ratio of the aniline to the solute in the saturated solution, wherein the molar ratio is as follows: 1:0.5-5.

3. The method for preparing a non-mercury catalyst for preparing vinyl chloride through hydrochlorination of acetylene according to claim 2, wherein the method comprises the following steps: the atmosphere for calcining the nitrogen-containing precursor is nitrogen, argon or ammonia, the volume flow is 1-100 mL/min, the heating rate is 5-10 ℃/min, the temperature is 400-1100 ℃, and the constant temperature time is 1-7 h.

4. A non-mercury catalyst for the hydrochlorination of acetylene to vinyl chloride according to claims 1 and 2, which is used by the method comprising: drying and mixing hydrogen chloride and acetylene, and introducing the mixture into a fixed bed reactor filled with a nitrogen-containing porous carbon material catalyst to perform acetylene hydrochlorination reaction at the reaction temperature of 100 ℃ and the reaction pressure of normal pressure to 0.1 MPa, the volume flow ratio of the hydrogen chloride to the acetylene is 1-1.3, and the airspeed of the acetylene is 25-550 h^-1。

Technical Field

The invention belongs to the field of catalysts, and particularly relates to a non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene and a preparation method and a use method thereof.

Background

Polyvinyl chloride (PVC) resin is one of five engineering plastics in the world, and is widely applied. Due to the resource structure of rich coal, poor oil and less gas, the process route for producing PVC by using calcium carbide as a raw material accounts for about 80 percent of the whole production of the PVC in China. In the traditional process of producing Vinyl Chloride Monomer (VCM) by using a calcium carbide method, mercuric chloride is used as a catalyst, is highly toxic, is easy to sublimate to cause catalyst inactivation, pollutes the environment, has large consumption, and almost exhausts available mercury resources in the polyvinyl chloride industry of China. According to the international mercury convention, a green mercury-free catalyst for acetylene hydrochlorination is researched and created, and the method is the core and key for solving the difficult problem of the production process of the polyvinyl chloride by the acetylene method.

At present, research and development of mercury-free catalysts are mainly divided into two aspects: 1. the mercury-free metal catalyst can be divided into noble metal catalysts (such as Au, Pd, Pt, Ru, etc.) and non-noble metal catalysts (such as Zn, Bi, Cu, Sn, etc.). The noble metal catalyst has high activity and good stability, but the cost is too high; the non-noble metal catalyst has low price, but insufficient activity and poor stability. 2. Nonmetal catalysts, such as nitrogen-containing activated carbon, SiC @ N-C nanocomposites, nitrogen-doped carbon nanotubes, nitrogen-doped graphene, and the like. Its advantages are low cost, no pollution and low activity.

The invention provides a non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene and a preparation and use method thereof, which have the advantages of low cost, simple and easy preparation, no pollution and higher activity and stability than those of an industrial mercury catalyst under the same test conditions (the test temperature of the industrial mercury catalyst is the same as that of the industrial mercury catalyst, and other conditions are the same).

Disclosure of Invention

The invention aims to provide a non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene, and a preparation process and a using method of the catalyst are explained.

The invention relates to a non-mercury catalyst for preparing vinyl chloride by hydrochlorinating acetylene, which is a nitrogen-containing porous carbon material prepared from a nitrogen-containing organic precursor and used as a catalyst for the hydrochlorinating reaction of acetylene, and comprises the following chemical components in percentage by mole: 1-10% of N, 70-97% of C, 1-20% of O, and a small amount of one of Cl, B, F, P or S<1% of catalystThe specific surface area of the agent is 30-3000 m²/g。

The raw material used in the invention is a nitrogen-containing organic precursor which is one or more of polyaniline, melamine, polypyrrolidone or polyacrylamide. Wherein the polyaniline can be obtained from commercial sources or prepared by chemical oxidative polymerization, and has an average molecular weight of 3000-100000. In the process of preparing polyaniline by using a chemical oxidation polymerization method, the used raw material is aniline, the oxidant is ammonium persulfate, potassium dichromate, potassium iodate, ferric trichloride, manganese dioxide, cerium sulfate or hydrogen peroxide, and the doping acid is hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, boric acid, perchloric acid, hydrofluoric acid or acetic acid respectively.

The invention relates to a preparation method of a nitrogen-containing porous carbon material catalyst for preparing vinyl chloride through acetylene hydrochlorination, which comprises the following steps: the nitrogen-containing precursor is prepared by high-temperature roasting, activating and forming, and is sealed and stored in vacuum or under the protection of nitrogen.

In the process of preparing the nitrogen-containing polyaniline precursor by using a chemical oxidation polymerization method, aniline is dispersed and oxidant is dissolved by using different doping acids in an ice bath, oxidant solution is slowly and dropwise added into aniline solution, the solution is mixed with one or more of melamine, polypyrrolidone and polyacrylamide after the oxidant solution is added, the mixture is stirred for a certain time at a certain temperature and a certain stirring speed, the filtration is carried out, the used doping acid and distilled water are used for washing a solid product, and the filtrate is clarified. Solid product, or mixing with potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, zinc chloride or saturated solution of phosphoric acid as activating agent, and directly performing subsequent preparation steps, or drying at certain temperature for a certain time.

Compared with the prior art, the invention has the following advantages: the nitrogen-containing porous carbon material catalyst has the advantages of cheap and easily-obtained raw materials, simple preparation process, convenient operation and environmental friendliness, and the activity and the stability of the catalyst are higher than those of a mercury catalyst, so that the catalyst can replace the mercury catalyst.

The use method of the nitrogen-containing porous carbon material catalyst for preparing vinyl chloride by hydrochlorination of acetylene comprises the following steps: the method comprises the steps of drying and mixing hydrogen chloride and acetylene, introducing the mixture into a fixed bed reactor filled with a nitrogen-containing porous carbon material catalyst to carry out acetylene hydrochlorination, and keeping a certain temperature, pressure, empty tower gas velocity of acetylene and volume flow of hydrogen chloride and acetylene gas.

Drawings

FIG. 1 is a graph of the acetylene conversion versus reaction time for examples one and two;

FIG. 2 is a graph of acetylene conversion versus reaction time for examples three, four, and five.

Detailed Description

The invention is further illustrated by the following specific examples. These examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure in any way whatsoever. After reading the disclosure of the present invention, various changes or modifications made based on the principle of the present invention also fall within the scope of the present invention as defined in the appended claims.

The first embodiment is as follows:

the method comprises the following specific steps:

(1) 10 mL of aniline and 250 mL of 1 mol/L hydrochloric acid are weighed and mixed uniformly to obtain a solution A, and 24.9 g of ammonium persulfate is weighed and dissolved completely in 100 mL of 1 mol/L hydrochloric acid to obtain a solution B.

(2) Solution A, B was simultaneously placed in an ice-water mixing bath and after 30 min, solution B was slowly added dropwise to solution A. After the completion of the dropwise addition, the mixed solution was stirred at a rotation speed of 600 r/min for 3 hours.

(3) And filtering the solution, repeatedly washing the solid product with residual 1 mol/L hydrochloric acid and a large amount of distilled water for many times until the filtrate is clear, and then drying the solid product at 60 ℃ for 6 hours and then placing the solid product at 50 ℃ for vacuum drying for 12 hours to obtain the polyaniline.

(4) Roasting the polyaniline prepared in the above steps at high temperature to obtain N₂Heating to 900 ℃ at a speed of 5 ℃/min under the atmosphere of 10 mL/min, keeping the temperature for 3 h, naturally cooling to room temperature to obtain the nitrogen-containing porous carbon material, and molding to obtain the mercury-free acetylene hydrochlorination catalyst named as Cl-AC. And (4) storing in vacuum.

(5) A certain amount of catalystThe catalyst is placed in a constant temperature section of a fixed bed reactor with the inner diameter of 10 mm, and the acetylene hydrochlorination catalytic performance of the catalyst is evaluated. The technological conditions of acetylene hydrochlorination are as follows:T=220 ℃ (reaction temperature 140 using industrial mercury catalyst)^oC)，GHSV(C₂H₂)=314 h^-1Volumetric flow rateV _(HCl):V _(C2H2)=1.1: 1. Product analysis was performed using a gas chromatograph (GC-7900). FIG. 1 shows the curve of the conversion of acetylene with the reaction time, HgCl, for Cl-AC in the case of the nitrogen-containing porous carbon material catalyst prepared in this example₂Is the curve of acetylene conversion with reaction time for a commercial mercury catalyst.

Example two:

the method comprises the following specific steps:

(1) 10 mL of aniline and 250 mL of 1 mol/L phosphoric acid are weighed and mixed uniformly to obtain a solution A, and 24.9 g of ammonium persulfate is weighed and dissolved completely in 100 mL of 1 mol/L phosphoric acid to obtain a solution B.

(2) Solution A, B was simultaneously placed in an ice-water mixing bath and after 30 min, solution B was slowly added dropwise to solution a. After the completion of the dropwise addition, the mixed solution was stirred at a rotation speed of 600 r/min for 3 hours.

(3) And filtering the solution, repeatedly washing the solid product with the residual 1 mol/L phosphoric acid and a large amount of distilled water for many times until the filtrate is clear, and then drying the solid product at 60 ℃ for 6 hours and then placing the solid product at 50 ℃ for vacuum drying for 12 hours to obtain the polyaniline.

(4) Roasting the polyaniline prepared in the above steps at high temperature to obtain N₂Heating to 900 ℃ at a flow rate of 10 mL/min at a speed of 5 ℃/min, keeping the temperature for 3 h, naturally cooling to room temperature to obtain the nitrogen-containing porous carbon material, and molding to obtain the mercury-free catalyst named as P-AC. And (4) storing in vacuum.

(5) And (3) placing a certain amount of catalyst in a constant-temperature section of a fixed bed reactor with the inner diameter of 10 mm, and carrying out acetylene hydrochlorination catalytic performance evaluation on the catalyst. The technological conditions of acetylene hydrochlorination are as follows:T=300 ℃ (reaction temperature 140 using industrial mercury catalyst)^oC)，GHSV(C₂H₂)=314 h^-1Volumetric flow rateV _(HCl):V _(C2H2)=1.1: 1. Product analysis was performed using a gas chromatograph (GC-7900). FIG. 1 is a graph showing that P-AC represents the HgCl, the acetylene conversion rate, as a function of the reaction time, of the nitrogen-containing porous carbon material catalyst prepared in this example₂Is the curve of acetylene conversion with reaction time for a commercial mercury catalyst.

Example three:

the method comprises the following specific steps:

(1) 10 mL of aniline and 250 mL of 1 mol/L phosphoric acid are weighed and mixed uniformly to obtain a solution A, and 24.9 g of ammonium persulfate is weighed and dissolved completely in 100 mL of 1 mol/L phosphoric acid to obtain a solution B.

(2) Solution A, B was simultaneously placed in an ice-water mixing bath and after 30 min, solution B was slowly added dropwise to solution a. After completion of the dropwise addition, 13.9 g of melamine was slowly added, and the mixed solution was stirred at a rotation speed of 600 r/min for 3 hours.

(3) And filtering the solution, repeatedly washing the solid product with the residual 1 mol/L phosphoric acid and a large amount of distilled water for many times until the filtrate is clear, and then drying the solid product at 60 ℃ for 6 hours and then placing the solid product at 50 ℃ for vacuum drying for 12 hours to obtain the polyaniline.

(4) Roasting the polyaniline prepared in the above steps at high temperature to obtain N₂Respectively heating to 900 ℃ at a flow rate of 10 mL/min at a speed of 5 ℃/min, keeping the temperature for 3 h, then naturally cooling to room temperature to prepare the nitrogen-containing porous carbon material catalyst, and molding to obtain the mercury-free catalyst, namely the ME-PANI-AC. And (4) storing in vacuum.

(5) And (3) placing a certain amount of catalyst in a constant-temperature section of a fixed bed reactor with the inner diameter of 10 mm, and carrying out acetylene hydrochlorination catalytic performance evaluation on the catalyst. The technological conditions of acetylene hydrochlorination are as follows:T=300 ℃ (reaction temperature 140 using industrial mercury catalyst)^oC)，GHSV(C₂H₂)=314 h^-1Volumetric flow rateV _(HCl):V _(C2H2)=1.1: 1. Product analysis was performed using a gas chromatograph (GC-7900). ME-PANI-AC in FIG. 2 is shown in the present embodimentThe prepared nitrogen-containing porous carbon material catalyst has the variation curve of acetylene conversion rate along with reaction time, HgCl₂Is the curve of acetylene conversion with reaction time for a commercial mercury catalyst.

Example four:

the method comprises the following specific steps:

(1) 10 mL of aniline and 250 mL of 1 mol/L phosphoric acid are weighed and mixed uniformly to obtain a solution A, and 24.9 g of ammonium persulfate is weighed and dissolved completely in 100 mL of 1 mol/L phosphoric acid to obtain a solution B.

(2) Solution A, B was simultaneously placed in an ice-water mixing bath and after 30 min, solution B was slowly added dropwise to solution a. After completion of the dropwise addition, 13.9 g of melamine and 7.8 g of polyacrylamide were slowly added, and the mixed solution was stirred at a rotation speed of 600 r/min for 3 hours.

(3) And filtering the solution, repeatedly washing the solid product with the residual 1 mol/L phosphoric acid and a large amount of distilled water for many times until the filtrate is clear, and then drying the solid product at 60 ℃ for 6 hours and then placing the solid product at 50 ℃ for vacuum drying for 12 hours to obtain the polyaniline.

(4) Roasting the polyaniline prepared in the above steps at high temperature to obtain N₂Respectively heating to 900 ℃ at a flow rate of 10 mL/min at a speed of 5 ℃/min, keeping the temperature for 3 h, naturally cooling to room temperature to obtain the nitrogen-containing porous carbon material catalyst, and molding to obtain the mercury-free catalyst named as ME-PAM-PANI-AC. And (4) storing in vacuum.

(5) And (3) placing a certain amount of catalyst in a constant-temperature section of a fixed bed reactor with the inner diameter of 10 mm, and carrying out acetylene hydrochlorination catalytic performance evaluation on the catalyst. The technological conditions of acetylene hydrochlorination are as follows:T=300 ℃ (reaction temperature 140 using industrial mercury catalyst)^oC)，GHSV(C₂H₂)=314 h^-1Volumetric flow rateV _(HCl):V _(C2H2)=1.1: 1. Product analysis was performed using a gas chromatograph (GC-7900). In FIG. 2, ME-PAM-PANI-AC is the curve of the conversion rate of acetylene with the change of reaction time, HgCl, of the nitrogen-containing porous carbon material catalyst prepared in this example₂Acetylene conversion as a function of reaction time for commercial mercury catalystsA wire.

Example five:

the method comprises the following specific steps:

(1) 10 mL of aniline and 250 mL of 1 mol/L hydrochloric acid are weighed and mixed uniformly to obtain a solution A, and 17.8 g of ferric trichloride is weighed and dissolved completely in 100 mL of 1 mol/L hydrochloric acid to obtain a solution B.

(2) Solution A, B was simultaneously placed in an ice-water mixing bath and after 30 min, solution B was slowly added dropwise to solution a. After the completion of the dropwise addition, the mixed solution was stirred at a rotation speed of 600 r/min for 3 hours.

(3) And filtering the solution, repeatedly washing the solid product with the residual 1 mol/L hydrochloric acid and a large amount of distilled water for many times until the filtrate is clear, and then drying the solid product at 60 ℃ for 6 hours and then placing the solid product at 50 ℃ for vacuum drying for 12 hours to obtain the polyaniline.

(4) Roasting the polyaniline prepared in the above steps at high temperature to obtain N₂Heating to 900 ℃ at a speed of 5 ℃/min under the atmosphere of 10 mL/min, keeping the temperature for 3 h, naturally cooling to room temperature to prepare the nitrogen-containing porous carbon material catalyst, and molding to obtain the mercury-free catalyst named as Fe-AC. And (4) storing in vacuum.

T ^o ₂₂ ^-1 V _(HCl) V _(C2H2)2。