阅读说明：本技术 一种用于乙炔氢氯化反应的复合金属盐催化剂 (Composite metal salt catalyst for acetylene hydrochlorination ) 是由 周奕丰 成昌梅 金启 于 2019-10-12 设计创作，主要内容包括：本发明属于乙炔氢氯化反应的复合金属盐催化剂技术领域,具体涉及一种用于乙炔氢氯化反应的复合金属盐催化剂及其应用。所述催化剂组成包括贵金属元素、非贵金属元素、助催化剂、载体以及助剂,所述贵金属元素重量占催化剂总重量0.01wt％-1wt％,所述非贵金属元素占催化剂总重量0.5wt％-10wt％,助催化剂占催化剂总重量2wt％-4wt％,所述助剂占催化剂总重量1wt％-10wt％；所述贵金属元素和非贵金属元素均以金属化合物形式存在。该催化剂的制作方法简单,能有效提高催化剂的生产效率和催化活性,在成本上也具有一定的优势,应用在氯乙烯生产过程中,能有效提高氯乙烯的生产效率。(The invention belongs to the technical field of composite metal salt catalysts for acetylene hydrochlorination, and particularly relates to a composite metal salt catalyst for acetylene hydrochlorination and application thereof. The catalyst comprises noble metal elements, non-noble metal elements, a promoter, a carrier and an auxiliary agent, wherein the noble metal elements account for 0.01 wt% -1 wt% of the total weight of the catalyst, the non-noble metal elements account for 0.5 wt% -10 wt% of the total weight of the catalyst, the promoter accounts for 2 wt% -4 wt% of the total weight of the catalyst, and the auxiliary agent accounts for 1 wt% -10 wt% of the total weight of the catalyst; the noble metal elements and the non-noble metal elements are both present in the form of metal compounds. The preparation method of the catalyst is simple, can effectively improve the production efficiency and catalytic activity of the catalyst, has certain advantages in cost, and can effectively improve the production efficiency of chloroethylene when being applied to the production process of chloroethylene.)

1. The composite metal salt catalyst for acetylene hydrochlorination comprises noble metal elements, non-noble metal elements, a cocatalyst, a carrier and an auxiliary agent, wherein the noble metal elements account for 0.01-1 wt% of the total weight of the catalyst, the non-noble metal elements account for 0.5-10 wt% of the total weight of the catalyst, the cocatalyst accounts for 2-4 wt% of the total weight of the catalyst, and the auxiliary agent accounts for 1-10 wt% of the total weight of the catalyst; the noble metal elements and the non-noble metal elements are both present in the form of metal compounds.

2. The complex metal salt catalyst of claim 1, wherein: the noble metal element comprises Ru; the non-noble metal elements comprise one or more metal elements of Cu, Ni, K, Pb, Bi and Rh.

3. The complex metal salt catalyst of claim 2, wherein: the non-noble metal element is a mixture of K and Bi, wherein the weight ratio of K to Bi is 0.5-1: 1.

4. The complex metal salt catalyst of claim 2, wherein: the non-noble metal element is a mixture of Pb, Rh and Bi, wherein the weight ratio of Pb, Rh and Bi is 0.2-0.5:1: 1-3.

5. The complex metal salt catalyst of claim 1, wherein: the cocatalyst is a mixture of potassium chloride and barium chloride, wherein the mass ratio of potassium chloride: 1-3: 1; the complex metal salt catalyst of claim 1, wherein: the auxiliary agent is tetraphenylphosphonium bromide.

6. The complex metal salt catalyst of claim 1, wherein: the carrier is selected from one or more of coconut shell activated carbon, coal activated carbon, shell activated carbon, molecular sieve and carbon nano tube.

7. The complex metal salt catalyst of claim 6, wherein: the carrier is a mixture of nutshell activated carbon and a molecular sieve, and the mass ratio of the nutshell activated carbon to the molecular sieve is 1-3: 1.

8. The complex metal salt catalyst of claim 6, wherein: the carrier is a mixture of nutshell activated carbon, a molecular sieve and a carbon nano tube, and the mass ratio of the nutshell activated carbon to the molecular sieve to the carbon nano tube is 1-2: 1-4: 1.

9. the method for preparing a complex metal salt catalyst according to any one of claims 1 to 8, comprising the steps of:

(1) the method comprises the following steps of (1) determining the mass of a prepared catalyst by taking a noble metal element, a non-noble metal element and a carrier as raw materials, and then determining the mass of a noble metal compound, a non-noble metal compound, an auxiliary agent and a carrier added with a solvent according to the proportion of the noble metal element, the non-noble metal element, the auxiliary agent and the carrier in the total mass of the catalyst;

(2) dissolving a noble metal compound and a non-noble metal compound in deionized water, and continuously stirring until solutes are completely dissolved to obtain a metal solution;

(3) dividing the metal solution into three equal parts, namely a first part solution, a second part solution and a third part solution;

(4) diluting the first solution, adding a carrier, soaking for 2-3h, heating the soaked liquid-solid mixture to 30-40 ℃ for 30-50min, then heating to 60-80 ℃ for 20-30min, then heating to 110-120 ℃ for constant temperature for 4-6h to obtain a primary drying material;

(5) diluting the second part of solution, adding an auxiliary agent, putting the primary dried substance, and soaking for 4-5 h; heating the impregnated liquid-solid mixture to 30-40 ℃ for 20-30min, then heating to 70-90 ℃ for 20-30min, then heating to 110-120 ℃ for constant temperature for 2-3h to obtain a secondary drying substance;

(6) taking the third solution, adding a cocatalyst, putting the secondary dried substance into the third solution, and soaking for 1-2 hours; heating the impregnated liquid-solid mixture to 40-50 ℃ for 30-60min, then heating to 80-90 ℃ for 30-50min, then heating to 110-120 ℃ for constant temperature for 6-8h to obtain a third-time dried substance;

(7) sintering the third-time drying material at the temperature of 300-500 ℃ to obtain the composite metal salt catalyst.

10. A method for producing vinyl chloride comprises the following steps:

(1) loading the composite metal catalyst of any one of 1 to 8 or the composite metal salt catalyst prepared according to claim 9 into a reaction tube, and activating in an atmosphere of hydrogen chloride for 40min to 50 min;

(2) the temperature range is adjusted as follows: 120-180 ℃; the pressure range is 0.1MPa-2 MPa; the airspeed range is as follows: 150h^-1-400h^-1And reacting under the conditions to obtain vinyl chloride.

Technical Field

The invention belongs to the technical field of composite metal salt catalysts for acetylene hydrochlorination, and particularly relates to a composite metal salt catalyst for acetylene hydrochlorination and application thereof.

Background

Vinyl chloride is a very important basic chemical raw material, and is mainly used for producing polyvinyl chloride. Since the earliest commercial production of vinyl chloride by the hydrochlorination of acetylene, the process for the production of vinyl chloride has been under development and transformation for over a hundred years. Currently, the main production methods of vinyl chloride are acetylene hydrochlorination and ethylene oxychlorination. The hydrochlorination of acetylene has the advantages of simple process, high conversion rate and simple post-treatment process.

The vinyl chloride production process is continuously improved in industrial production, and 5 main production processes are formed: ethylene oxychlorination, acetylene hydrochlorination, dichloroethane process, ethane oxychlorination, equilibrium oxychlorination; the acetylene hydrochlorination method is the earliest method for industrially producing vinyl chloride, and has the advantages of simple process, low investment, high yield, high power consumption, serious pollution, high toxicity of catalyst mercury salt, and suitability for large-scale production due to the limitation of safe production, environmental protection and the like.

The acetylene hydrochlorination method is the most typical addition reaction and needs to be carried out under the action of a catalyst. The process can be divided into three steps of acetylene preparation and refining, vinyl chloride synthesis and product refining. Mercuric chloride with activated carbon as a carrier is used as a catalyst.

The acetylene method for synthesizing vinyl chloride still adopts a catalyst of mercuric chloride loaded on an active carbon carrier in the industry, but the mercury catalyst is easy to sublimate and lose to bring toxicity and pollution, and the development of a non-mercury catalyst is not mature at the present stage, so the acetylene method is particularly important for developing a novel low-mercury catalyst.

Reducing the loading of the noble metal gold is the most effective way to reduce the cost, with high selectivity and high conversion being achieved. Reducing the gold loading necessarily reduces the catalytic efficiency, so we must reduce the gold loading while also increasing the catalytic efficiency. According to the basic principle of equilibrium constant, in the reaction of reduced volume, increasing the pressure helps the reaction go forward. It is therefore presumed that, in the reaction for producing vinyl chloride, increasing the pressure contributes to the improvement of the catalytic efficiency.

Chinese patent application CN 108404941 a discloses a composite metal salt catalyst for acetylene hydrochlorination and its application, which is characterized in that: the catalyst comprises noble metal elements, non-noble metal elements, a carrier and an auxiliary agent, wherein the noble metal elements account for 0.01 wt% -2 wt% of the total weight of the catalyst, the non-noble metal elements account for 0.01 wt% -20 wt% of the total weight of the catalyst, and the auxiliary agent accounts for 0.05 wt% -15 wt% of the total weight of the catalyst; the noble metal elements and the non-noble metal elements are both present in the form of metal compounds. In the reaction process, the catalytic efficiency can be effectively improved and the use amount of noble metal can be reduced by changing the reaction conditions, particularly under the pressurizing condition. However, the technology disclosed in this patent still needs to be improved in terms of catalyst synthesis process efficiency, catalytic activity, cost, and the like.

Disclosure of Invention

In order to overcome the technical problems, the invention provides the composite metal salt catalyst for the hydrochlorination of acetylene, the preparation method of the catalyst is simple, the production efficiency and the catalytic activity of the catalyst can be effectively improved, certain advantages are realized in cost, and the catalyst can be effectively used for improving the production efficiency of vinyl chloride in the production process of vinyl chloride.

In order to achieve the above purpose, the technical scheme provided by the invention is as follows:

the composite metal salt catalyst for acetylene hydrochlorination comprises noble metal elements, non-noble metal elements, a cocatalyst, a carrier and an auxiliary agent, wherein the noble metal elements account for 0.01-1 wt% of the total weight of the catalyst, the non-noble metal elements account for 0.5-10 wt% of the total weight of the catalyst, the cocatalyst accounts for 2-4 wt% of the total weight of the catalyst, and the auxiliary agent accounts for 1-10 wt% of the total weight of the catalyst; the noble metal elements and the non-noble metal elements are both present in the form of metal compounds.

Preferably, the weight of the noble metal element accounts for 0.02 wt% -1 wt% of the total weight of the catalyst;

the noble metal element includes Ru.

The non-noble metal elements comprise one or more metal elements of Cu, Ni, K, Pb, Bi and Rh.

Preferably, the non-noble metal element is a mixture of K and Bi, wherein the weight ratio of K to Bi is 0.5-1: 1;

preferably, the non-noble metal element is a mixture of Pb, Rh and Bi, wherein the weight ratio of Pb, Rh and Bi is 0.2-0.5:1: 1-3;

by weight, noble metal elements: non-noble metal elements are 1: 10-50.

The cocatalyst is a mixture of potassium chloride and barium chloride, wherein the mass ratio of potassium chloride: barium chloride 1-3: 1.

The auxiliary agent is tetraphenylphosphonium bromide (TPPB).

The carrier is selected from one or more of coconut shell activated carbon, coal activated carbon, shell activated carbon, molecular sieve and carbon nano tube.

Preferably, the carrier is a mixture of the nutshell activated carbon and a molecular sieve, and the mass ratio of the nutshell activated carbon to the molecular sieve is 1-3: 1;

preferably, the carrier is a mixture of nutshell activated carbon, a molecular sieve and a carbon nanotube, and the mass ratio of the nutshell activated carbon to the molecular sieve to the carbon nanotube is 1-2: 1-4: 1;

the metal compound exists in the form of one or more than two of metal chloride, phosphate and sulfate.

Preferably, the metal compound exists in the form of one or two combinations selected from nitrate and acetate.

Another object of the present invention is to provide a method for preparing the complex metal salt catalyst, comprising the steps of:

(1) the method comprises the following steps of (1) determining the mass of a prepared catalyst by taking a noble metal element, a non-noble metal element and a carrier as raw materials, and then determining the mass of a noble metal compound, a non-noble metal compound, an auxiliary agent and a carrier added with a solvent according to the proportion of the noble metal element, the non-noble metal element, the auxiliary agent and the carrier in the total mass of the catalyst;

(2) dissolving a noble metal compound and a non-noble metal compound in deionized water, and continuously stirring until solutes are completely dissolved to obtain a metal solution;

(3) dividing the metal solution into three equal parts, namely a first part solution, a second part solution and a third part solution;

(4) diluting the first solution, adding a carrier, soaking for 2-3h, heating the soaked liquid-solid mixture to 30-40 ℃ for 30-50min, then heating to 60-80 ℃ for 20-30min, then heating to 110-120 ℃ for constant temperature for 4-6h to obtain a primary drying material;

(5) diluting the second part of solution, adding an auxiliary agent, putting the primary dried substance, and soaking for 4-5 h; heating the impregnated liquid-solid mixture to 30-40 ℃ for 20-30min, then heating to 70-90 ℃ for 20-30min, then heating to 110-120 ℃ for constant temperature for 2-3h to obtain a secondary drying substance;

(6) taking the third solution, adding a cocatalyst, putting the secondary dried substance into the third solution, and soaking for 1-2 hours; heating the impregnated liquid-solid mixture to 40-50 ℃ for 30-60min, then heating to 80-90 ℃ for 30-50min, then heating to 110-120 ℃ for constant temperature for 6-8h to obtain a third-time dried substance;

(7) sintering the third-time drying material at the temperature of 300-500 ℃ to obtain the composite metal salt catalyst.

Preferably, in step (4), the first portion of solution is diluted 2-3 times;

preferably, in the step (4), the temperature rising rate is 1-2 ℃/min;

preferably, in the step (5), the temperature rising rate is 0.5-1 ℃/min;

preferably, in the step (5), the second solution is diluted to 1-2 times;

preferably, in the step (6), the temperature rise rate is 0.5-1 ℃/min.

The invention also aims to provide a method for producing vinyl chloride, which comprises the following steps:

(1) the catalyst or the catalyst prepared by the preparation method of the composite metal salt catalyst is filled into a reaction tube and activated in the atmosphere of hydrogen chloride for 40-50 min.

(2) The temperature range is adjusted as follows: 120-180 ℃; the pressure range is 0.1MPa-2 MPa; the airspeed range is as follows: 150h^-1-400h^-1And reacting under the conditions to obtain vinyl chloride.

Compared with the prior art, the invention has the technical advantages that:

(1) the three-stage impregnation mode is adopted, so that the impregnation liquid can be fully loaded on the carrier, and the effective utilization rate of the metal elements is improved;

(2) the carrier is impregnated by adopting the impregnation liquid with different concentrations, so that the metal elements are favorably dispersed on the carrier, the utilization rate of the metal elements is improved, and the catalytic activity of the catalyst is enhanced;

(3) the auxiliary agent and the cocatalyst are respectively added into the impregnation liquid during the second and third times of impregnation, so that the catalytic activity of the catalyst is improved;

(4) the invention greatly reduces the content of noble metal by adjusting the pressure and the temperature, but can reach the activity equivalent to that of a catalyst with high content of noble metal;

(5) in catalysts with very low noble metal content, a higher activity is still obtained by adjusting the conditions. Thereby greatly reducing the production cost;

(6) in the reaction process, the catalytic efficiency can be effectively improved and the use amount of noble metal can be reduced by changing the reaction conditions, particularly under the pressurizing condition. The catalyst has low content of noble metal and high catalytic efficiency, is a catalyst with good activity, high stability, high conversion rate and strong selectivity, and the preparation process of the chloroethylene is easy to regulate and control.

(7) On the premise of the same catalytic efficiency, the cost for producing the chloroethylene is 30-40% of the cost for producing the chloroethylene by using the catalyst prepared from the noble metal Au, so that the production cost is greatly reduced

Detailed Description