A method for preparing a copper-based catalyst and its application in the catalytic hydrochlorination of acetylene.

Abstract

This invention discloses a method for preparing a copper-based catalyst and its application in the catalytic hydrochlorination of acetylene. The Cu / Cu-PAC catalyst of this invention exhibits good activity, selectivity, and stability in the acetylene-to-vinyl chloride synthesis reaction.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a method for preparing a copper-based catalyst and its application in the catalytic hydrochlorination of acetylene. Background Technology

[0002] Polyvinyl chloride (PVC) is one of the three major general-purpose resins. Industrial production of PVC mainly employs the acetylene process, using mercury-based catalysts. However, mercury-based catalysts have serious impacts on human health and the environment during their preparation and catalytic reaction. Therefore, the development of mercury-free catalysts is urgently needed.

[0003] Research on non-mercury-based catalysts has primarily focused on both metal and non-metal catalysts. Precious metal catalysts are limited in reserves and expensive, hindering large-scale application. Non-metal catalysts, on the other hand, exhibit low catalytic activity and fail to meet industrial requirements. Copper-based catalysts offer high catalytic activity and are inexpensive, but their activity and stability remain challenges. Therefore, developing a highly efficient and stable copper-based catalyst is crucial for the sustainable development of the vinyl chloride industry. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0005] As one aspect of the present invention, the present invention provides a method for preparing a copper-based catalyst, comprising,

[0006] Step (1): Dissolve the copper salt in water and the tetraphenylphosphine bromide in a solvent. Mix the two solutions. The molar ratio of tetraphenylphosphine bromide to copper salt is 0.25 to 0.5:1.

[0007] Step (2): Add activated carbon to the mixed solution obtained in step (1) and stir;

[0008] Step (3): Remove the solvent at 110-120℃ to obtain a mixture, and then dry the mixture;

[0009] Step (4): Under a nitrogen atmosphere, the mixture dried in step (3) is heated to 900-950℃, kept at that temperature for 2-6 hours, and then cooled to obtain the catalyst Cu-PAC;

[0010] Step (5): Dissolve copper salt in water, add the catalyst Cu-PAC, stir thoroughly, remove the solvent to obtain a mixture, dry it, heat the mixture to 800℃ under a nitrogen atmosphere, keep it at the temperature for 2-6 hours, cool it, and obtain the catalyst Cu / Cu-PAC-800.

[0011] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (1), the solvent includes ethanol and the copper salt includes copper chloride.

[0012] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (2), the mass ratio of the activated carbon to the copper salt in step (1) is 2:0.2-0.4.

[0013] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (2), the stirring time is 4 to 5 hours.

[0014] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (3), the drying time is 12-14 hours.

[0015] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (4), the mixture after drying in step (3) is heated to 900°C at a rate of 5°C / min and kept at that temperature for 4 hours.

[0016] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (5), the concentration of copper salt is 1.5 to 2.0 wt%, the mass ratio of copper salt to Cu-PAC is 0.08 to 0.09:1, and the mixture is stirred thoroughly for 4 to 5 hours.

[0017] As a preferred embodiment of the preparation method of the copper-based catalyst of the present invention: in step (5), the mixture is heated to 800°C at a heating rate of 5°C / min under a nitrogen atmosphere and kept at the temperature for 4 hours.

[0018] The beneficial effects of this invention are as follows: The acetylene hydrochlorination catalyst prepared by this invention overcomes the limitation of poor stability of non-precious metal copper-based catalysts for the acetylene hydrochlorination reaction. By optimizing the catalyst preparation method, this invention yields a catalyst with high stability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein:

[0020] Figure 1 The figures show the experimental results of various embodiments of the present invention. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0022] Example 1:

[0023] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and 0.189g of tetraphenylphosphine bromide in 5mL of anhydrous ethanol. Mix the two solutions together in a total of 10mL. The molar ratio of tetraphenylphosphine bromide to copper chloride is 0.25:1.

[0024] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0025] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0026] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-PAC.

[0027] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-PAC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 800 °C at a heating rate of 5 °C / min under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-PAC-800.

[0028] Step (6): Take 1 mL of the catalyst Cu / Cu-PAC-800 obtained in step (5) and put it into a fixed-bed reactor. The reaction conditions are: hydrogen chloride activation for 30 min, acetylene space velocity (GSHV) 180 h⁻¹, reaction temperature 180 °C, and feed gas ratio of V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these conditions yielded an initial conversion of 61.9% for acetylene. After 50 hours of reaction, the acetylene conversion reached 60.54%, with a conversion decay rate of 0.027% / h, indicating a highly stable reaction process. The selectivity for vinyl chloride was greater than 99%.

[0029] At a reaction temperature of 200℃, with other conditions remaining constant, the initial conversion rate was 64.76%, and after 50 hours of reaction, the acetylene conversion rate reached 67.72%. The reaction process was very stable, with the catalyst continuously activated during the reaction. The selectivity for vinyl chloride was greater than 99%.

[0030] Take 1 mL of the catalyst Cu / Cu-PAC-800 obtained in step (5) and put it into a fixed-bed reactor. The reaction conditions are: activation with hydrogen chloride for 30 min and acetylene space velocity (GSHV) of 90 h⁻¹. -1The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these reaction conditions yielded an initial conversion rate of 75.3% for acetylene and a conversion rate of 77.9% after 12 hours of reaction, indicating that the reaction process was very stable and the selectivity for vinyl chloride was greater than 99%.

[0031] Example 2:

[0032] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and 0.189g of tetraphenylphosphine bromide in 5mL of anhydrous ethanol. Mix the two solutions together in a total of 10mL. The molar ratio of tetraphenylphosphine bromide to copper chloride is 0.25:1.

[0033] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0034] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0035] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-PAC.

[0036] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-PAC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 400 °C at a rate of 5 °C per minute under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained. It is named Cu / Cu-PAC-400.

[0037] Step (6): Take 1 mL of the obtained catalyst Cu / Cu-PAC-400 and put it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction is carried out. -1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl =1:1.15. Under these reaction conditions, the acetylene hydrochlorination reaction was catalyzed, and the initial conversion rate of acetylene was 78.6%. After 42 hours of reaction, the acetylene conversion rate was 50.7%, and the selectivity of vinyl chloride was greater than 99%. After adjusting the preparation temperature of step (5) to 400℃, although the initial conversion rate of the acetylene hydrochlorination reaction was higher, the reaction stability decreased.

[0038] Example 3:

[0039] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and 0.189g of tetraphenylphosphine bromide in 5mL of anhydrous ethanol. Mix the two solutions together in a total of 10mL. The molar ratio of tetraphenylphosphine bromide to copper chloride is 0.25:1.

[0040] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0041] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0042] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-PAC.

[0043] Step (5): Take 1 mL of the obtained catalyst and place it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction proceeds. 1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these reaction conditions yielded an initial conversion rate of 42.34% for acetylene, which reached 43.9% after 30 hours of reaction. The selectivity for vinyl chloride was greater than 99%.

[0044] Example 4:

[0045] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and 0.0945g of tetraphenylphosphine bromide in 5mL of anhydrous ethanol. Mix the two solutions together in a total of 10mL. The molar ratio of tetraphenylphosphine bromide to copper chloride is 0.125:1.

[0046] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0047] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0048] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-PAC.

[0049] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-PAC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 800 °C at a rate of 5 °C per minute under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-PAC-0.125.

[0050] Step (6): Take 1 mL of the obtained catalyst and place it into a fixed-bed reactor. The reaction conditions are: hydrogen chloride activation for 30 min, acetylene space velocity of 180 h⁻¹, reaction temperature of 180 °C, and feed gas ratio of V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these reaction conditions yielded an initial conversion rate of 44.5% for acetylene, which reached 42.9% after 20 hours of reaction. The selectivity for vinyl chloride was greater than 99%.

[0051] Example 5:

[0052] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and 0.378g of tetraphenylphosphine bromide in 5mL of anhydrous ethanol. Mix the two solutions together in a total of 10mL. The molar ratio of tetraphenylphosphine bromide to copper chloride is 0.5:1.

[0053] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0054] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0055] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-PAC.

[0056] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-PAC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 800 °C at a rate of 5 °C per minute under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-PAC-0.5.

[0057] Step (6): Take 1 mL of the obtained catalyst and put it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction is carried out. -1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these reaction conditions yielded an initial conversion rate of 56.6% for acetylene, a conversion rate of 48.1% after 50 hours of reaction, and a selectivity for vinyl chloride greater than 99%.

[0058] Example 6:

[0059] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and hydroxyethylidene diphosphonic acid in 5mL of anhydrous ethanol. Mix the two solutions thoroughly. The molar ratio of hydroxyethylidene diphosphonic acid to copper chloride is 0.25:1.

[0060] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0061] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0062] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-P1AC.

[0063] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-P1AC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 800 °C at a heating rate of 5 °C / min under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-P1AC-800.

[0064] Step (6): Take 1 mL of the obtained catalyst and put it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction is carried out. -1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HClWith a ratio of 1:1.15, the acetylene hydrochlorination reaction was catalyzed under these conditions, resulting in an initial acetylene conversion rate of 65.4%. After 20 hours of reaction, the acetylene conversion rate reached 57.4%, and gradually decreased as the reaction progressed, with a decay rate of 0.4% / h. The selectivity for vinyl chloride was greater than 99%.

[0065] Example 7:

[0066] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water and phytic acid in 5mL of anhydrous ethanol. Mix the two solutions thoroughly. The molar ratio of phytic acid to copper chloride is 0.25:1.

[0067] Step (2): Add 2g of activated carbon (Fujian Sensen Carbon Industry Technology Co., Ltd., coconut shell activated carbon, 40-80 mesh) to the mixed solution obtained in step (1) and stir thoroughly for 4 hours.

[0068] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0069] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-P2AC.

[0070] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-P2AC, stir thoroughly for 4 h, remove the solvent at 120 °C, and dry the mixture for 12 h. Place the mixture in an alumina boat, heat to 800 °C at a rate of 5 °C per minute under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-P2AC-800.

[0071] Step (6): Take 1 mL of the obtained catalyst and put it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction is carried out. -1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl With a ratio of 1:1.15, the acetylene hydrochlorination reaction was catalyzed under these conditions, resulting in an initial acetylene conversion rate of 64.1%. After 20 hours of reaction, the acetylene conversion rate reached 57.1%, and gradually decreased as the reaction progressed, with a decay rate of 0.35% / h. The selectivity for vinyl chloride was greater than 99%.

[0072] Example 8:

[0073] Step (1): Dissolve 0.3073g of copper chloride in 5mL of deionized water.

[0074] Step (2): Add 2g of activated carbon to the above solution and stir thoroughly for 4 hours.

[0075] Step (3): Remove the solvent at 120°C to obtain a mixture, and dry it for 12 hours.

[0076] Step (4): The mixture obtained in step (3) was placed in an alumina boat and heated to 900°C at a rate of 5°C / min under a nitrogen atmosphere, and held at that temperature for 4 hours. After cooling to room temperature, the catalyst was obtained and named Cu-AC.

[0077] Step (5): Dissolve 0.174 g of copper chloride in 10 mL of deionized water, stir and mix for 30 min, add 2 g of catalyst Cu-AC, stir thoroughly for 4 h, remove the solvent at 120 °C to obtain a mixture, and dry the mixture for 12 h. Place the mixture in an alumina boat, and heat it to 800 °C at a heating rate of 5 °C / min under a nitrogen atmosphere, and hold at that temperature for 4 h. After cooling to room temperature, the catalyst is obtained and named Cu / Cu-AC.

[0078] Step (6): Take 1 mL of the obtained catalyst and put it into a fixed-bed reactor. Under the reaction conditions of hydrogen chloride activation for 30 min and acetylene space velocity of 180 h⁻¹, the reaction is carried out. -1 The reaction temperature is 180℃, and the feed gas ratio is V. C2H2 V HCl With a ratio of 1:1.15, the catalytic hydrochlorination of acetylene under these reaction conditions yielded an initial conversion rate of 22.4% for acetylene, which increased to 23.1% after 50 hours of reaction. The selectivity for vinyl chloride was greater than 99%.

[0079] In summary, the Cu / Cu-PAC catalyst of this invention exhibits good activity, selectivity, and stability in the acetylene-to-vinyl chloride synthesis reaction, achieving a reaction time of 180 h. -1 At a volume hourly space velocity (VHSV), the initial acetylene conversion reached 61.9%, with an acetylene conversion decay rate of 0.027% / h, while the vinyl chloride selectivity remained above 99%. Moreover, under these reaction conditions, the catalyst prepared in this invention exhibited excellent acetylene conversion and stability. Figure 1 The catalytic performance of different catalysts was screened by (a) calcination temperature and (b) P / Cu molar ratio.

[0080] The above description is merely a preferred embodiment of the present invention. Any person skilled in the art can modify the present invention or modify it into an equivalent technical solution using the technical solutions described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a copper-based catalyst, characterized in that: include, Step (1): Dissolve the copper salt in water and the tetraphenylphosphine bromide in a solvent. Mix the two solutions. The molar ratio of tetraphenylphosphine bromide to copper salt is 0.25~0.5:

1. Step (2): Add activated carbon to the mixed solution obtained in step (1) and stir; Step (3): Remove the solvent at 110~120℃ to obtain a mixture, and then dry the mixture; Step (4): Under a nitrogen atmosphere, the mixture dried in step (3) is heated to 900~950℃, kept at that temperature for 2~6h, and then cooled to obtain the catalyst Cu-PAC; Step (5): Dissolve copper salt in water, add the catalyst Cu-PAC, stir thoroughly, remove the solvent to obtain a mixture, dry it, heat the mixture to 800℃ under a nitrogen atmosphere, keep it at the temperature for 2~6h, cool it to obtain catalyst Cu / Cu-PAC-800; In step (1), the solvent is ethanol, the copper salt is copper chloride, and the copper salt is dissolved in water at a concentration of 5-7 wt%. In step (2), the mass ratio of the activated carbon to the copper salt in step (1) is 2:0.2~0.4; The concentration of copper salt is 1.5~2.0wt%, and the mass ratio of copper salt to Cu-PAC is 0.08~0.09:

1. Stir thoroughly for 4~5 h.

2. The method for preparing the copper-based catalyst according to claim 1, characterized in that: In step (2), the stirring time is 4-5 hours.

3. The method for preparing the copper-based catalyst according to claim 1 or 2, characterized in that: In step (3), the drying time is 12-14 hours.

4. The method for preparing the copper-based catalyst according to claim 1 or 2, characterized in that: In step (4), the mixture dried in step (3) is heated to 900°C at a rate of 5°C / min and kept at that temperature for 4 hours.

5. The method for preparing the copper-based catalyst according to claim 1 or 2, characterized in that: In step (5), the mixture is heated to 800°C at a heating rate of 5°C / min under a nitrogen atmosphere and held at that temperature for 4 hours.

6. The application of the copper-based catalyst prepared by the method according to claim 1 in the catalytic hydrochlorination of acetylene.

7. The application according to claim 6, characterized in that: The reaction temperature is 180~200℃, and the feed gas ratio is V. C2H2 :V HCl =1:1.15, acetylene space velocity is 90~180h -1 The volume of the catalyst Cu / Cu-PAC-800 is 1 mL.

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