阅读说明：本技术 一种基于fau分子筛的氯乙烯无汞触媒及其制备方法 (Vinyl chloride mercury-free catalyst based on FAU molecular sieve and preparation method thereof ) 是由 李通 于 2021-01-25 设计创作，主要内容包括：本发明提供一种基于FAU分子筛的氯乙烯无汞触媒的制备方法,所述制备方法包括：FAU分子筛预处理、浸渍、FAU分子筛后处理、负载、烘干、激活。本发明还提供一种基于FAU分子筛的氯乙烯无汞触媒,其在180-195℃反应温度下即可实现最佳的催化性能,并且在反应过程中,几乎无副产物的产生,终端产品质量好。在反应温度为180-195℃,乙炔空速60-70～(-1)条件下,副反应损耗定额小于1.02kg/t,终端产品中高沸物副产物含量小于0.03%,乙炔初始转化率大于99.1%,氯乙烯选择性大于99.0%。(The invention provides a preparation method of a chloroethylene mercury-free catalyst based on an FAU molecular sieve, which comprises the following steps: FAU molecular sieve pretreatment, impregnation, FAU molecular sieve post-treatment, loading, drying and activation. The invention also provides a vinyl chloride mercury-free catalyst based on the FAU molecular sieve, which can realize the optimal catalytic performance at the reaction temperature of 180-195 ℃, almost has no by-product in the reaction process and has good quality of the end product. At the reaction temperature of 180 ℃ plus 195 ℃ and the acetylene space velocity of 60-70 ‑1 Under the condition, the loss quota of the side reaction is less than 1.02kg/t, the content of the high-boiling-point substance by-product in the terminal product is less than 0.03 percent, the initial conversion rate of acetylene is more than 99.1 percent, and the selectivity of chloroethylene is more than 99.0 percent.)

1. A preparation method of a vinyl chloride mercury-free catalyst based on an FAU molecular sieve is characterized by comprising the following steps: pretreating, dipping, post-treating, loading, drying and activating an FAU molecular sieve;

pretreating the FAU molecular sieve, including roasting, spraying liquid and balancing;

performing after-treatment on the FAU molecular sieve, including drying and heat treatment;

the spray liquid is characterized in that when the roasted Zn-Y type FAU molecular sieve raw powder is naturally cooled to 65-70 ℃, the modification liquid is uniformly sprayed on the surface of the Zn-Y type FAU molecular sieve raw powder for spray liquid modification;

the modifying solution comprises: acetone, N-dimethylformamide and polyethylene glycol.

2. The method for preparing a mercury-free vinyl chloride catalyst based on an FAU molecular sieve as claimed in claim 1, wherein the spraying time is 8-10 min;

the dosage of the modifying liquid is 1-3 times of the volume of the Zn-Y type FAU molecular sieve raw powder;

the acetone: n, N-dimethylformamide: the weight ratio of the polyethylene glycol is 10-15:5-9: 2-3.

3. The method for preparing vinyl chloride mercury-free catalyst based on FAU molecular sieve as claimed in claim 1, wherein the calcination comprises placing Zn-Y type FAU molecular sieve raw powder in a predetermined portion under oxygen-rich atmosphere, raising the temperature to 350-400 ℃ at a rate of 3-5 ℃/min, and maintaining the temperature for 1-2h after the temperature is raised;

the content of Fe in the Zn-Y type FAU molecular sieve raw powder is 1.1-1.4 wt%;

the oxygen-enriched atmosphere contains 30-35% of oxygen and the balance of nitrogen.

4. The method as claimed in claim 1, wherein the impregnation comprises: primary impregnation;

the first dipping is carried out, the modified Zn-Y type FAU molecular sieve prepared by the FAU molecular sieve pretreatment is put into a first dipping solution, heated to 60 ℃, stirred and dipped to prepare the modified Zn/Cu-Y type FAU molecular sieve;

the primary impregnation liquid is a copper chloride solution;

the concentration of the copper chloride solution is 25-35%.

5. The method as claimed in claim 1, wherein the impregnation further comprises: secondary impregnation;

the second impregnation is to put the modified Zn-Y FAU molecular sieve subjected to the first impregnation into a second impregnation solution, heat the solution to 70 ℃ and perform impregnation to prepare the impregnated modified Zn/Cu-Y FAU molecular sieve;

the secondary impregnation liquid is ammonium chloride solution;

the concentration of the ammonium chloride solution is 15-20%.

6. The method for preparing vinyl chloride mercury-free catalyst based on FAU molecular sieve as claimed in claim 1, wherein the heat treatment comprises putting the dried modified Zn/Cu-Y type FAU molecular sieve into hydrogen atmosphere, heating to 130 ℃, keeping the temperature, and performing heat treatment for 3-4 h.

7. The method for preparing vinyl chloride mercury-free catalyst based on FAU molecular sieve as claimed in claim 1, wherein the loading comprises putting the modified Zn/Cu-Y type FAU molecular sieve prepared by the FAU molecular sieve post-treatment into a negative carrier liquid with volume of 3-5 times, heating to 40-50 ℃, preserving heat, stirring and loading for 2-3 h; the negative carrier liquid comprises absolute ethyl alcohol, N-methyl pyrrolidone and N-ethyl pyrrolidone.

8. The method for preparing vinyl chloride mercury-free catalyst based on FAU molecular sieve as claimed in claim 1, wherein the drying step is carried out, and the modified Zn/Cu-Y type FAU molecular sieve loaded with active ingredients and prepared in the loading step is placed at 80-90 ℃ for drying at low temperature for 4-5 h.

9. The preparation method of the FAC molecular sieve based mercury-free vinyl chloride catalyst as claimed in claim 1, wherein the activation is performed by controlling the temperature of the mercury-free catalyst within a range of 90-100 ℃ for 3-5min under a nitrogen atmosphere and under a batch microwave radiation condition on the dried modified Zn/Cu-Y type FAU molecular sieve loaded with the active component.

10. A mercury-free vinyl chloride catalyst based on FAU molecular sieve prepared by the preparation method of any one of claims 1-9, which is characterized in that the reaction temperature is 180-^-1Under the condition, the initial conversion rate of acetylene is more than 99.1 percent, and the loss quota of side reaction is less than 1.02 kg/t.

Technical Field

The invention relates to the field of mercury-free catalysts, in particular to a vinyl chloride mercury-free catalyst based on an FAU molecular sieve and a preparation method thereof.

Background

Vinyl chloride, a monomer for the synthesis of polyvinyl chloride. The polyvinyl chloride resin is an important plastic raw material, is one of five general synthetic resins, has good physical and mechanical properties, is widely applied to industrial products, building materials, pipes, decorative materials, wires and cables, and also has wide application in the aspects of packaging materials, sealing materials, fibers and the like. The production of vinyl chloride monomer is an important step in the polyvinyl chloride industry.

Currently, there are three major processes for the production of vinyl chloride worldwide, the acetylene, ethylene and ethane processes. The acetylene process is the earliest commercial technology for vinyl chloride production. The method has the advantages of simple flow and high conversion rate, but has the defects of higher power consumption, and particularly, the mercury-containing catalyst used in the method seriously harms the health of workers and causes serious environmental pollution. With the development of production processes, the acetylene law has been replaced by the route of the ethylene law in developed countries. However, China is a country with more coal, less gas and poor oil, and the ethylene output of China basically depends on petroleum completely. From 1993, China changes from a net export country of petroleum into an import country, particularly, the import quantity of the petroleum in China continuously increases in recent years, and the dependence on the imported petroleum is higher and higher.

Therefore, for our country, the acetylene process is still mainly and long-term adopted for producing vinyl chloride. The overall domestic vinyl chloride industrial layout is mainly concentrated in the northwest region. As early as 2015, mercury catalyst (HgCl 2%: not less than 10%) or low-mercury catalyst (HgCl 2%: 4% -6.5%) is used in the industry of preparing vinyl chloride by acetylene method in China for catalyzing the preparation of vinyl chloride. Because of the serious influence of mercury on the environment and human health, the preparation of the vinyl chloride by using the mercury-free catalyst has great significance.

At present, researches on mercury-free catalyst catalysts for acetylene-method polyvinyl chloride mainly comprise noble metal catalysts, non-noble metal catalysts and non-metal catalysts. Compared with noble metal catalysts and nonmetal catalysts, the non-noble metal catalyst has the characteristics of low cost, small environmental hazard, high catalytic activity and the like, can completely meet the requirement of industrial application, and gradually replaces mercury catalysts to become a dominant catalyst in the vinyl chloride industry.

The applicant finds that, in the current production process for preparing vinyl chloride by using an acetylene method by using a mercury-free catalyst, in order to avoid the defects that byproducts are easily generated at a higher reaction temperature and the quality and purity of a terminal product are affected, the existing process and catalyst usually adopt a method for reducing the reaction temperature so as to inhibit the generation of the byproducts and avoid the loss of effective components of the catalyst. However, with the above production method, on one hand, because the reaction of preparing chloroethylene by using acetylene method is exothermic reaction, and the method of reducing the reaction temperature is adopted, the temperature of the reaction system needs to be controlled by using a refrigerant and controlled within a relatively low temperature range, so that the energy consumption of the cooling system is high, and the overhaul and maintenance costs of the equipment are increased; on the other hand, the method of reducing the reaction temperature can reduce the reaction rate to a certain extent, and increase the production time and labor cost.

Chinese patent CN106492869A discloses a non-noble metal mercury-free catalyst for hydrochlorination of acetylene and a preparation method and application thereof, wherein copper salt, ammonium salt and phosphoric acid are used as catalyst active ingredients and are loaded on activated carbon to prepare the mercury-free catalyst. However, when the catalyst is used for catalyzing the hydrogenation reaction of acetylene chloride, the reaction temperature needs to be controlled at 130 ℃, the method needs to adopt a refrigerant to control the temperature of a reaction system, and the energy consumption of a cooling system is high; meanwhile, the reaction rate is reduced to a certain extent; the time, labor and equipment cost are high.

Chinese patent CN103894220B discloses a molecular sieve mercury-free catalyst for hydrochlorination of acetylene and a preparation method thereof, wherein 50-100 wt% of FAU type silicon-aluminum molecular sieve and 0-50 wt% of non-molecular sieve components of silicon dioxide and aluminum oxide are combined to prepare the catalyst. However, in the process of catalyzing the hydrogenation reaction of acetylene chloride by using the catalyst, the performance of the catalyst is attenuated quickly, specifically, the conversion rate is reduced, an additional catalyst regeneration process is needed to recover the performance of the catalyst, so that the time is wasted, and the normal continuous and stable operation of production is influenced; meanwhile, the catalytic life of the catalyst is not ideal enough and needs to be further improved.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a vinyl chloride mercury-free catalyst based on an FAU molecular sieve and a preparation method thereof, so as to realize the following purposes:

(1) the mercury-free catalyst is provided, and can effectively avoid the generation of byproducts and ensure the reaction efficiency while ensuring the optimal reaction temperature in the process of preparing chloroethylene by using an acetylene method;

(2) provides a mercury-free catalyst, which has lasting catalytic performance and ideal service life in the process of preparing chloroethylene by using acetylene method.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a preparation method of a vinyl chloride mercury-free catalyst based on an FAU molecular sieve comprises the following steps: pretreating, dipping, post-treating, loading, drying and activating an FAU molecular sieve;

pretreating the FAU molecular sieve, including roasting, spraying liquid and balancing;

performing after-treatment on the FAU molecular sieve, including drying and heat treatment;

the spray liquid is characterized in that when the roasted Zn-Y type FAU molecular sieve raw powder is naturally cooled to 65-70 ℃, the modification liquid is uniformly sprayed on the surface of the Zn-Y type FAU molecular sieve raw powder for spray liquid modification;

the modifying solution comprises: acetone, N-dimethylformamide and polyethylene glycol.

Further, spraying liquid for 8-10 min;

the dosage of the modifying liquid is 1-3 times of the volume of the Zn-Y type FAU molecular sieve raw powder;

the acetone: n, N-dimethylformamide: the weight ratio of the polyethylene glycol is 10-15:5-9: 2-3.

Further, roasting, namely placing the Zn-Y type FAU molecular sieve raw powder in a predetermined part under the condition of an oxygen-enriched atmosphere, heating to 350-400 ℃ at the heating rate of 3-5 ℃/min, and preserving heat for 1-2h after the heating is finished;

the content of Fe in the Zn-Y type FAU molecular sieve raw powder is 1.1-1.4 wt%;

the oxygen-enriched atmosphere contains 30-35% of oxygen and the balance of nitrogen.

Further, the impregnation comprises: primary impregnation;

the first dipping is carried out, the modified Zn-Y type FAU molecular sieve prepared by the FAU molecular sieve pretreatment is put into a first dipping solution, heated to 60 ℃, stirred and dipped to prepare the modified Zn/Cu-Y type FAU molecular sieve;

the primary impregnation liquid is a copper chloride solution;

the concentration of the copper chloride solution is 25-35%.

Further, the impregnation further comprises: secondary impregnation;

and in the second impregnation, the modified Zn-Y type FAU molecular sieve subjected to the first impregnation is put into a second impregnation solution, heated to 70 ℃ and impregnated to prepare the impregnated modified Zn/Cu-Y type FAU molecular sieve.

The secondary impregnation liquid is ammonium chloride solution;

the concentration of the ammonium chloride solution is 15-20%.

Further, the heat treatment is to put the dried modified Zn/Cu-Y type FAU molecular sieve into a hydrogen atmosphere, heat to 130 ℃, preserve heat and carry out heat treatment for 3-4 h.

Further, the loading is carried out by putting the modified Zn/Cu-Y type FAU molecular sieve prepared by the FAU molecular sieve post-treatment into a negative carrier liquid with the volume of 3-5 times, heating to 40-50 ℃, preserving heat, stirring and loading for 2-3 h; the negative carrier liquid comprises absolute ethyl alcohol, N-methyl pyrrolidone and N-ethyl pyrrolidone.

Further, drying, namely drying the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients and prepared in the loading step at a low temperature of 80-90 ℃ for 4-5 h.

Further, activating, namely controlling the temperature of the mercury-free catalyst within the range of 90-100 ℃ for 3-5min under the conditions of nitrogen atmosphere and intermittent microwave radiation on the dried modified Zn/Cu-Y type FAU molecular sieve loaded with the active ingredients.

The vinyl chloride mercury-free catalyst based on the FAU molecular sieve prepared by the preparation method has the advantages that the initial conversion rate of acetylene is more than 99.1 percent, and the loss quota of side reaction is less than 1.02kg/t under the conditions that the reaction temperature is 180-plus 195 ℃ and the acetylene space velocity is 60-70-1.

Compared with the prior art, the invention has the beneficial effects that:

(1) the vinyl chloride mercury-free catalyst based on the FAU molecular sieve can realize the optimal catalytic performance at the reaction temperature of 180-195 ℃, almost no by-product is generated in the reaction process, and the quality of a terminal product is good.

(2) According to the vinyl chloride mercury-free catalyst based on the FAU molecular sieve, when the catalyst is used for catalyzing the acetylene chloride hydrogenation reaction, the optimal catalytic performance can be realized at the reaction temperature of 180-195 ℃, the energy consumption of a temperature control system is effectively reduced, and the equipment maintenance cost can be saved while the energy is saved.

(3) The vinyl chloride mercury-free catalyst based on the FAU molecular sieve can realize the optimal catalytic performance at the reaction temperature of 180-195 ℃, has high efficiency and rapidness in reaction, and can shorten the reaction time by 7-9 percent, save the production time and save the labor cost compared with the mercury-free catalyst described in the traditional Chinese patent CN 106492869A.

(4) The vinyl chloride mercury-free catalyst based on the FAU molecular sieve has the advantages that under the conditions that the reaction temperature is 180-.

(5) According to the vinyl chloride mercury-free catalyst based on the FAU molecular sieve, detection shows that the initial conversion rate of acetylene is more than 99.1% and the selectivity of vinyl chloride is more than 99.0% under the conditions that the reaction temperature is 180-.

(6) The vinyl chloride mercury-free catalyst based on the FAU molecular sieve can effectively resist adverse factors such as temperature, poison, mechanical force, chemical erosion and the like in the reaction process, has lasting and stable catalytic activity, and has no difference between the catalytic performance of the catalyst and the performance of a new catalyst after the catalyst is used for 10000h through tests, and does not need regeneration and reactivation procedures in the process; the total service life of the catalyst exceeds 13000h, and the catalyst can meet the requirement of large-scale industrial production.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, specific embodiments of the present invention will now be described.

Example 1

A preparation method of a chloroethylene mercury-free catalyst based on an FAU molecular sieve comprises the steps of FAU molecular sieve pretreatment, impregnation, FAU molecular sieve post-treatment, loading, drying and activation.

And the FAU molecular sieve pretreatment comprises roasting, liquid spraying and balancing.

And (3) roasting, namely putting the Zn-Y type FAU molecular sieve raw powder in a predetermined part into an oxygen-enriched atmosphere, heating to 350 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1h after the heating is finished.

The Zn-Y type FAU molecular sieve raw powder contains 13wt% of template agent based on the total weight of the molecular sieve.

The content of Fe in the Zn-Y type FAU molecular sieve raw powder is 1.1 wt%.

In the oxygen-enriched atmosphere, the oxygen content is 30 percent, and the balance is nitrogen.

And (3) spraying liquid, namely, when the roasted Zn-Y type FAU molecular sieve raw powder is naturally cooled to 65 ℃, uniformly spraying a modification liquid on the surface of the Zn-Y type FAU molecular sieve raw powder within 8min, and completing the liquid spraying step to obtain the modified Zn-Y type FAU molecular sieve.

The dosage of the modifying liquid is 1 time of the volume of the Zn-Y type FAU molecular sieve raw powder.

The modified liquid is a mixed liquid of acetone, N-dimethylformamide, polyethylene glycol and deionized water. The acetone: n, N-dimethylformamide: polyethylene glycol: the weight ratio of the deionized water is 15:5:2: 70.

Balancing, separating out the modified Zn-Y type FAU molecular sieve prepared in the liquid spraying step, and standing for 20min at the temperature of 50 ℃ and the pressure of 10 MPa; then releasing the pressure to normal pressure, and drying at the low temperature of 70 ℃ for 1h to finish the balancing step.

The impregnation comprises primary impregnation and secondary impregnation.

And the first dipping is to put the modified Zn-Y type FAU molecular sieve into a predetermined part of first dipping solution with the volume 2 times that of the first dipping solution, heat the first dipping solution to 60 ℃, stir the first dipping solution at 20RPM for 2 hours, and filter out solids to prepare the modified Zn/Cu-Y type FAU molecular sieve.

The primary impregnation liquid is a copper chloride solution. The concentration of the copper chloride solution is 25%.

And in the second impregnation, the modified Zn-Y type FAU molecular sieve subjected to the first impregnation is put into a secondary impregnation liquid with the volume being 1.5 times that of the secondary impregnation liquid, the secondary impregnation liquid is heated to 70 ℃, the impregnation time is 1 hour, and the modified Zn/Cu-Y type FAU molecular sieve is filtered out.

The secondary impregnation liquid is ammonium chloride solution. The concentration of the ammonium chloride solution is 15%.

And (3) performing after-treatment on the FAU molecular sieve, including drying and heat treatment.

And drying, namely putting the modified Zn/Cu-Y type FAU molecular sieve prepared by secondary impregnation into an environment at 110 ℃ and drying for 1 h.

And in the heat treatment, the dried modified Zn/Cu-Y FAU molecular sieve is put into a hydrogen atmosphere, heated to 130 ℃, kept warm for 3 hours, completely replaced by H2 by N2, and naturally cooled to normal temperature, so that the heat treatment step is completed.

And loading, namely putting the modified Zn/Cu-Y FAU molecular sieve into a negative carrier liquid with the volume 3 times that of the modified Zn/Cu-Y FAU molecular sieve, heating to 40 ℃, stirring at 20RPM, preserving heat for 2 hours to finish the loading step, separating out solids, and preparing the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients.

The negative carrier liquid comprises absolute ethyl alcohol, N-methyl pyrrolidone, N-ethyl pyrrolidone and deionized water. The absolute ethyl alcohol: n-methylpyrrolidone: n-ethylpyrrolidone: the weight ratio of the deionized water is 2:2:1: 10.

And drying, namely drying the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients at a low temperature of 80 ℃ for 4 hours to finish the drying step.

And activating, namely controlling the temperature of the mercury-free catalyst to be within the range of 90-95 ℃ under the conditions of nitrogen atmosphere with the pressure of 1MPa and intermittent microwave radiation for 3min under the dried modified Zn/Cu-Y type FAU molecular sieve loaded with active ingredients, so as to complete the activation of the catalyst and prepare the vinyl chloride mercury-free catalyst based on the FAU molecular sieve.

The microwave radiation is 22w/g in microwave energy.

Through detection, the vinyl chloride mercury-free catalyst based on the FAU molecular sieve has the advantages that the initial conversion rate of acetylene is 99.2%, the selectivity of vinyl chloride is 99.4%, the loss quota of side reaction is 0.96kg/t, and the content of a high-boiling-point substance byproduct in a terminal product is 0.027% through detection under the conditions that the temperature is 190 ℃ and the acetylene airspeed is 70-1; compared with the mercury-free catalyst described in Chinese patent CN106492869A, the reaction time can be shortened by 7.2%; the total service life of the catalyst exceeds 13000h, and the catalyst can meet the requirement of large-scale industrial production.

Example 2

A preparation method of a chloroethylene mercury-free catalyst based on an FAU molecular sieve comprises the steps of FAU molecular sieve pretreatment, impregnation, FAU molecular sieve post-treatment, loading, drying and activation.

And the FAU molecular sieve pretreatment comprises roasting, liquid spraying and balancing.

And (3) roasting, namely putting the Zn-Y type FAU molecular sieve raw powder in a predetermined part into an oxygen-enriched atmosphere, heating to 380 ℃ at a heating rate of 3.5 ℃/min, and preserving heat for 2 hours after the heating is finished.

The Zn-Y type FAU molecular sieve raw powder contains a template agent with the weight of 14wt% of the total weight of the molecular sieve.

The content of Fe in the Zn-Y type FAU molecular sieve raw powder is 1.2 wt%.

In the oxygen-enriched atmosphere, the oxygen content is 35 percent, and the balance is nitrogen.

And (3) spraying liquid, namely, when the roasted Zn-Y type FAU molecular sieve raw powder is naturally cooled to 65 ℃, uniformly spraying a modification liquid on the surface of the Zn-Y type FAU molecular sieve raw powder within 8min, and completing the liquid spraying step to obtain the modified Zn-Y type FAU molecular sieve.

The dosage of the modifying liquid is 1.6 times of the volume of the Zn-Y type FAU molecular sieve raw powder.

The modified liquid is a mixed liquid of acetone, N-dimethylformamide, polyethylene glycol and deionized water. The acetone: n, N-dimethylformamide: polyethylene glycol: the weight ratio of deionized water is 12:8: 3: 65.

Balancing, separating out the modified Zn-Y type FAU molecular sieve prepared in the liquid spraying step, and standing for 30min at the temperature of 55 ℃ and under the pressure of 14 MPa; then releasing the pressure to normal pressure, and drying at the low temperature of 75 ℃ for 2h to finish the balancing step.

The impregnation comprises primary impregnation and secondary impregnation.

And the first dipping is to put the modified Zn-Y FAU molecular sieve into a predetermined part of primary dipping solution with the volume being 2.5 times of that of the primary dipping solution, heat the primary dipping solution to 60 ℃, stir the primary dipping solution at 30RPM for 3 hours, and filter out solids to prepare the modified Zn/Cu-Y FAU molecular sieve.

The primary impregnation liquid is a copper chloride solution. The concentration of the copper chloride solution is 32%.

And in the second impregnation, the modified Zn-Y type FAU molecular sieve subjected to the first impregnation is put into a secondary impregnation liquid with the volume being 1.8 times that of the secondary impregnation liquid, the secondary impregnation liquid is heated to 70 ℃, the impregnation time is 1.5 hours, and the modified Zn/Cu-Y type FAU molecular sieve is filtered out.

The secondary impregnation liquid is ammonium chloride solution. The concentration of the ammonium chloride solution is 18%.

And (3) performing after-treatment on the FAU molecular sieve, including drying and heat treatment.

And drying, namely putting the modified Zn/Cu-Y type FAU molecular sieve prepared by secondary impregnation into an environment at 110 ℃ and drying for 2 h.

And in the heat treatment, the dried modified Zn/Cu-Y FAU molecular sieve is put into a hydrogen atmosphere, heated to 130 ℃, kept warm for 3.5 hours, completely replaced by H2 by N2, and naturally cooled to normal temperature, so that the heat treatment step is completed.

And loading, namely putting the modified Zn/Cu-Y FAU molecular sieve into a negative carrier liquid with the volume 4 times that of the modified Zn/Cu-Y FAU molecular sieve, heating to 50 ℃, stirring at 20RPM, preserving heat for 3 hours to finish the loading step, separating out solids, and preparing the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients.

The negative carrier liquid comprises absolute ethyl alcohol, N-methyl pyrrolidone, N-ethyl pyrrolidone and deionized water. The absolute ethyl alcohol: n-methylpyrrolidone: n-ethylpyrrolidone: the weight ratio of the deionized water is 2:2:1: 10.

And drying, namely drying the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients at a low temperature of 85 ℃ for 5 hours to finish the drying step.

And activating, namely controlling the temperature of the mercury-free catalyst to be within the range of 90-95 ℃ under the conditions of nitrogen atmosphere with the pressure of 1.2MPa and intermittent microwave radiation for 5min under the dried modified Zn/Cu-Y type FAU molecular sieve loaded with active ingredients, and completing the activation of the catalyst to obtain the vinyl chloride mercury-free catalyst based on the FAU molecular sieve.

The microwave radiation is 22w/g in microwave energy.

Through detection, the vinyl chloride mercury-free catalyst based on the FAU molecular sieve has the advantages that the initial conversion rate of acetylene is more than 99.5%, the selectivity of vinyl chloride is more than 99.4%, the loss quota of side reaction is less than 0.87kg/t, and the content of high-boiling-point by-products in a terminal product is less than 0.019% through detection under the conditions that the temperature is 190 ℃ and the airspeed of acetylene is 70-1; compared with the mercury-free catalyst described in Chinese patent CN106492869A, the reaction time can be shortened by 9%; the total service life of the catalyst exceeds 13000h, and the catalyst can meet the requirement of large-scale industrial production.

Example 3

A preparation method of a chloroethylene mercury-free catalyst based on an FAU molecular sieve comprises the steps of FAU molecular sieve pretreatment, impregnation, FAU molecular sieve post-treatment, loading, drying and activation.

And the FAU molecular sieve pretreatment comprises roasting, liquid spraying and balancing.

And (3) roasting, namely putting the Zn-Y type FAU molecular sieve raw powder in a predetermined part into an oxygen-enriched atmosphere, heating to 400 ℃ at a heating rate of 5 ℃/min, and preserving heat for 1h after the heating is finished.

The Zn-Y type FAU molecular sieve raw powder contains 15wt% of template agent based on the total weight of the molecular sieve.

The content of Fe in the Zn-Y type FAU molecular sieve raw powder is 1.4 wt%.

The oxygen-enriched atmosphere contains 33% of oxygen and the balance of nitrogen.

And (3) spraying liquid, namely, when the roasted Zn-Y type FAU molecular sieve raw powder is naturally cooled to 70 ℃, uniformly spraying a modification liquid on the surface of the Zn-Y type FAU molecular sieve raw powder within 8min, and completing the liquid spraying step to obtain the modified Zn-Y type FAU molecular sieve.

The dosage of the modifying liquid is 3 times of the volume of the Zn-Y type FAU molecular sieve raw powder.

The modified liquid is a mixed liquid of acetone, N-dimethylformamide, polyethylene glycol and deionized water. The acetone: n, N-dimethylformamide: polyethylene glycol: the weight ratio of the deionized water is 15:6:3: 70.

Balancing, separating out the modified Zn-Y type FAU molecular sieve prepared in the liquid spraying step, and standing for 20min at the temperature of 55 ℃ and the pressure of 14 MPa; then releasing the pressure to normal pressure, and drying at the low temperature of 80 ℃ for 1h to finish the balancing step.

The impregnation comprises primary impregnation and secondary impregnation.

And the first dipping is to put the modified Zn-Y type FAU molecular sieve into a predetermined part of first dipping solution with the volume being 3 times that of the first dipping solution, heat the first dipping solution to 60 ℃, stir the first dipping solution at 50RPM for 3 hours, and filter out solids to prepare the modified Zn/Cu-Y type FAU molecular sieve.

The primary impregnation liquid is a copper chloride solution. The concentration of the copper chloride solution is 35%.

And in the secondary impregnation, the modified Zn-Y type FAU molecular sieve subjected to the primary impregnation is put into secondary impregnation liquid with the volume being 2 times that of the primary impregnation, the secondary impregnation liquid is heated to 70 ℃, the impregnation time is 2 hours, and the modified Zn/Cu-Y type FAU molecular sieve is filtered out.

The secondary impregnation liquid is ammonium chloride solution. The concentration of the ammonium chloride solution is 20%.

And (3) performing after-treatment on the FAU molecular sieve, including drying and heat treatment.

And drying, namely putting the modified Zn/Cu-Y type FAU molecular sieve prepared by secondary impregnation into an environment at 110 ℃ and drying for 2 h.

And in the heat treatment, the dried modified Zn/Cu-Y FAU molecular sieve is put into a hydrogen atmosphere, heated to 130 ℃, kept warm for 4 hours, completely replaced by H2 by N2, and naturally cooled to normal temperature, so that the heat treatment step is completed.

And loading, namely putting the modified Zn/Cu-Y FAU molecular sieve into a negative carrier liquid with the volume 5 times that of the modified Zn/Cu-Y FAU molecular sieve, heating to 50 ℃, stirring at 50RPM, preserving heat for 3 hours to finish the loading step, separating out solids, and preparing the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients.

The negative carrier liquid comprises absolute ethyl alcohol, N-methyl pyrrolidone, N-ethyl pyrrolidone and deionized water. The absolute ethyl alcohol: n-methylpyrrolidone: n-ethylpyrrolidone: the weight ratio of the deionized water is 2:2:1: 10.

And drying, namely drying the modified Zn/Cu-Y FAU molecular sieve loaded with the active ingredients at a low temperature of 90 ℃ for 5 hours to finish the drying step.

And activating, namely controlling the temperature of the mercury-free catalyst to be within the range of 95-100 ℃ under the conditions of nitrogen atmosphere with the pressure of 2MPa and intermittent microwave radiation for 5min under the dried modified Zn/Cu-Y type FAU molecular sieve loaded with active ingredients, and completing the activation of the catalyst to obtain the vinyl chloride mercury-free catalyst based on the FAU molecular sieve.

The microwave radiation is 22w/g in microwave energy.

Through detection, the vinyl chloride mercury-free catalyst based on the FAU molecular sieve has the advantages that the initial conversion rate of acetylene is more than 99.3%, the selectivity of vinyl chloride is more than 99.5%, the loss quota of side reaction is 0.92kg/t, and the content of a high-boiling-point substance byproduct in a terminal product is 0.022% through detection under the conditions that the acetylene airspeed is 70-1 at 190 ℃; compared with the mercury-free catalyst described in Chinese patent CN106492869A, the reaction time can be shortened by 8.1%; the total service life of the catalyst exceeds 13000h, and the catalyst can meet the requirement of large-scale industrial production.

All percentages used in the present invention are mass percentages unless otherwise indicated.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.