阅读说明：本技术 一种工业用氯乙烯合成无汞催化剂及制备方法和应用 (Industrial mercury-free catalyst synthesized from vinyl chloride, and preparation method and application thereof ) 是由 那珊 于 2020-08-06 设计创作，主要内容包括：本发明涉及一种工业用氯乙烯合成无汞催化剂及制备方法和应用,属于氯乙烯合成催化剂技术领域,催化剂包括载体和活性组分,载体为耐酸载体颗粒,活性组分为铜氯化物,以铜的重量计,活性组分在载体上的负载量为3-30%,该催化剂,具有高活性、低成本、使用寿命长的优点。制备方法中,采用气体搅拌的方式,将活性组分以等体积浸渍法或过量浸渍法负载在载体上。该制备方法,使活性组分均匀的负载在载体上,提高了催化剂的活性和使用寿命。应用中,采用乙炔和氯化氢合成氯乙烯的方法,包括至少两组串联的反应器组,位于下游的反应器组更换下来的催化剂用于位于上游的反应器组中。该应用,实现催化剂的回收利用,降低了氯乙烯生产成本。(The invention relates to a mercury-free catalyst synthesized by industrial vinyl chloride, a preparation method and application thereof, belonging to the technical field of catalysts synthesized by vinyl chloride, wherein the catalyst comprises a carrier and an active component, the carrier is acid-resistant carrier particles, the active component is copper chloride, and the loading amount of the active component on the carrier is 3-30% by weight of copper. In the preparation method, the active component is loaded on the carrier by an equal-volume impregnation method or an excess impregnation method in a gas stirring mode. The preparation method enables the active component to be uniformly loaded on the carrier, improves the activity of the catalyst and prolongs the service life of the catalyst. In use, the process for the synthesis of vinyl chloride from acetylene and hydrogen chloride comprises at least two series-connected reactor groups, the catalyst replaced by the downstream reactor group being used in the upstream reactor group. The application realizes the recycling of the catalyst and reduces the production cost of the chloroethylene.)

1. The industrial mercury-free catalyst synthesized by vinyl chloride is characterized in that: the catalyst comprises a carrier and an active component, wherein the carrier is an acid-resistant carrier particle, the active component is copper chloride, and the loading amount of the active component on the carrier is 3-30% by weight of copper.

2. The industrial mercury-free catalyst for synthesizing vinyl chloride according to claim 1, which is characterized in that: the copper chloride is copper chloride, the mechanical strength of the carrier is 93-98%, and the saturated water absorption of the carrier is 20-70%.

3. The industrial mercury-free catalyst for synthesizing vinyl chloride according to claim 2, which is characterized in that: the carrier is a columnar carrier, and the columnar carrier is activated carbon particles.

4. The industrial mercury-free catalyst for synthesizing vinyl chloride according to claim 3, which is characterized in that: the column shapeThe average diameter of the carrier is 3.0-4.5mm, the average length is 4-9mm, the specific surface area is 700-1200m²/g。

5. The industrial mercury-free catalyst for synthesizing vinyl chloride according to claim 2, which is characterized in that: the carrier is a spherical carrier, and the spherical carrier is silica gel particles.

6. The industrial mercury-free catalyst for synthesizing vinyl chloride according to claim 5, which is characterized in that: the average particle size of the spherical carrier is 3.5-6.0mm, and the specific surface area is 200-600m²/g。

7. A method for preparing industrial mercury-free catalyst synthesized by vinyl chloride according to any one of claims 1 to 6, characterized in that: the active component is loaded on the carrier by an equal volume impregnation method or an excess impregnation method by adopting a gas stirring mode.

8. The method for preparing mercury-free catalyst for industrial synthesis of vinyl chloride according to claim 7, wherein the method comprises the following steps: the method adopts an excess impregnation method, and specifically comprises the following steps:

a1, preparing the active components into a solution to obtain a precursor solution, wherein the temperature of the precursor solution is 35-80 ℃;

a2, placing the precursor solution in a carrier, contacting the precursor solution with the carrier, absorbing the precursor solution by the carrier, wherein the volume of the precursor solution is 0.5-3.0 times of the volume of the carrier;

a3, introducing gas into the precursor solution to turn the carrier in the precursor solution for 300min, wherein the turning time is 200-;

a4, stopping introducing gas into the precursor solution, settling the carrier in the precursor solution, standing for 30-40min, and separating to obtain a primary finished product;

a5, drying the primary product at 100-170 ℃ for 13-16h to obtain the catalyst.

9. The method for preparing mercury-free catalyst for industrial synthesis of vinyl chloride according to claim 7, wherein the method comprises the following steps: the method adopts an isometric immersion method, and specifically comprises the following steps:

s1, preparing the active components into a solution to obtain a precursor solution, wherein the temperature of the precursor solution is 35-80 ℃;

s2, placing the carrier in a mixing container, introducing gas into the mixing container, and turning over the carrier in the mixing container;

s3, introducing a precursor solution into the mixing container, introducing the precursor solution into the mixing container for multiple times, wherein the time interval between the introduction of the precursor solution in two adjacent times is 40-60min, the introduction of the precursor solution is finished within 240min after 160-one times, and when the precursor solution enters the mixing container, the precursor solution is contacted with the carrier and is absorbed by the carrier;

s4, stopping introducing gas into the mixing container after the precursor solution is introduced, settling the carrier at the bottom of the mixing container, and standing for 40-60min to obtain a primary finished product;

s5, drying the primary product at the drying temperature of 100 ℃ and 170 ℃ for 13-16h to obtain the catalyst.

10. Use of the industrial mercury-free catalyst for vinyl chloride synthesis according to any of claims 1 to 6, in a process for vinyl chloride synthesis using acetylene and hydrogen chloride, characterized in that: the reactor comprises at least two groups of reactor groups connected in series, catalysts are respectively filled in the multiple groups of reactor groups, and the catalyst replaced by the reactor group positioned at the downstream is used in the reactor group positioned at the upstream.

Technical Field

The invention relates to the technical field of catalysts for synthesizing vinyl chloride, in particular to a mercury-free catalyst for synthesizing industrial vinyl chloride, a preparation method and application thereof.

Background

The chloroethylene-based resin has excellent performance and low price, and is widely applied to important fields of industry, agriculture, building materials and the like. With the development of socio-economy, the use of vinyl chloride-based resins is expanding and the demand is increasing. After the polyvinyl chloride is industrialized, acetylene is generally produced by adopting calcium carbide, the acetylene and hydrogen chloride are used for producing vinyl chloride under the action of a mercuric chloride-activated carbon catalyst, and the polyvinyl chloride is obtained by polymerizing the vinyl chloride. Although the mercuric chloride-activated carbon catalyst has the advantages of high catalytic activity and good selectivity to vinyl chloride, the content of mercuric chloride in the mercuric chloride-activated carbon catalyst is 4-12%, and mercury elements generated in the using process of the mercuric chloride-activated carbon catalyst seriously pollute the environment, so the mercuric-free catalyst is produced at the same time and a great deal of research is carried out, but the research only stays in a laboratory due to the limitation of the activity and the service life of the mercuric-free catalyst, and industrial mass production cannot be realized.

The patent application publication No. CN101716508A discloses a catalyst for synthesizing chloroethylene from acetylene and a preparation method thereof, wherein the chemical components of the catalyst mainly comprise an active component, a cocatalyst component and a carrier, the catalyst contains 2-15% of palladium or gold chloride and 1-5% of rare earth chloride, and the carrier is activated carbon. The catalyst is prepared by loading palladium or gold chloride on a carrier and using rare earth chloride as a cocatalyst, but the palladium or gold chloride and the rare earth chloride are in short resource and expensive price, so that industrial mass production and application are difficult to realize.

At present, the patent application publication No. CN102029189A discloses a non-mercury catalyst for hydrochlorination of acetylene and a method for preparing vinyl chloride using the catalyst, wherein the catalyst comprises a main active component of gold salt, an auxiliary active component of non-noble metal salt and a carrier, the main active component is selected from halides or complexes of gold, and the auxiliary active component of non-noble metal salt is selected from one or more of halides, acetates, phosphates and complexes of potassium, barium, lanthanum and copper. In the catalyst, the halide or the complex of gold is supported on a carrier, and although non-noble metal salt is used as a component active component, the halide or the complex of gold is inevitably required to be used, so that the application of industrial mass production is difficult to realize.

At present, the patent application publication No. CN102069000A discloses a non-mercury catalyst for producing vinyl chloride and a preparation method thereof, the non-mercury catalyst uses coconut shell activated carbon as a carrier, and stannous chloride as a main active substance, wherein the mass percentage of the stannous chloride is 15-30%, and at least one additive of barium chloride, zinc chloride and copper chloride is also added. After the catalyst is continuously operated for 603 hours, the reaction conversion rate is reduced to 95.0 percent, the catalyst is poor in stability and short in service life, and the requirement of industrial production cannot be met.

At present, patent document with application publication number CN106492869B discloses a non-noble metal mercury-free catalyst for hydrochlorination of acetylene, and a preparation method and application thereof, wherein the preparation method of the catalyst comprises the following steps: 1) preparing a copper salt, an ammonium salt and phosphoric acid or a mixed solution of the copper salt, the ammonium salt and the phosphate; 2) adding activated carbon into the mixed solution obtained in the step 1) for soaking; 3) spin-drying the soaked activated carbon, and then heating and drying to obtain the catalyst; wherein, Cu: n: the molar ratio of P is 1:0.2-1.2: 0.1-1.0. According to the catalyst, copper salt, ammonium salt and phosphoric acid or copper salt, ammonium salt and phosphate are loaded on a carrier and continuously run for 1000 hours, the reaction conversion rate is reduced to 89.32%, and although the service life of the catalyst is slightly prolonged, the service life of the mercuric chloride-activated carbon catalyst cannot be reached.

At present, a patent document with application publication number CN106944151B discloses a mercury-free catalyst for synthesizing vinyl chloride by hydrochlorinating acetylene, and a preparation method and application thereof, wherein the preparation method of the catalyst comprises the following steps: 1) dissolving base metal salt and an amide solvent in water to prepare a mixed solution; 2) adding activated carbon into the mixed solution obtained in the step 1) for impregnation; 3) filtering, draining and then heating and drying the activated carbon obtained in the step 2) to obtain the catalyst; wherein the base metal salt is selected from copper salt, the amide solvent is selected from one or more of butyrolactam, butyrolactam derivative, valerolactam derivative, caprolactam and caprolactam derivative; in the step 3), the drying temperature is 120-. According to the catalyst, base metal salt and an amide solvent are loaded on a carrier and continuously run for 1000 hours, the reaction conversion rate is reduced to 92.1%, and although the service life of the catalyst is slightly prolonged, the service life of a mercuric chloride-activated carbon catalyst cannot be reached.

Therefore, there is an urgent need to research a catalyst with low cost and long service life to realize the industrial mass production thereof.

Disclosure of Invention

The invention aims to provide an industrial mercury-free catalyst synthesized by vinyl chloride, which has the advantages of high activity, low cost and long service life.

The second purpose of the invention is to provide a preparation method of the mercury-free catalyst synthesized by industrial vinyl chloride, which adopts a gas stirring mode to uniformly load active components on a carrier, thereby improving the activity and the service life of the catalyst.

The third purpose of the invention is to provide a preparation method of the mercury-free catalyst synthesized by industrial vinyl chloride, which realizes the recycling of the catalyst and reduces the production cost of vinyl chloride.

The above object of the present invention is achieved by the following technical solutions:

the catalyst for synthesizing mercury-free catalyst with vinyl chloride includes carrier and active component, the carrier is acid-resisting carrier particle, the active component is copper chloride, and the supported amount of the active component on the carrier is 3-30 wt% of copper.

By adopting the technical scheme, the mixed gas of acetylene and hydrogen chloride reacts under the catalysis of the catalyst to generate chloroethylene. Because the mixed gas of the hydrogen chloride and the acetylene contains moisture inevitably, even if concentrated sulfuric acid is used for dehydration, the removal of the moisture in the mixed gas cannot be finished, when the mixed gas of the acetylene and the hydrogen chloride contacts with a carrier, the carrier absorbs the water in the mixed gas of the acetylene and the hydrogen chloride, at the moment, the hydrogen chloride gas is dissolved in the water and forms strong acid, and acid-resistant carrier particles are adopted in the application, so that the influence of the strong acid on the carrier is reduced, the gas flow of the acetylene and the hydrogen chloride is kept, and the conversion rate of the acetylene, the activity of a catalyst and the capacity of vinyl chloride are kept. The active component is copper chloride, the loading capacity of the active component is 3-30%, the reaction of gold on acetylene and hydrogen chloride has good catalytic activity, and copper and gold belong to the same period and also have good catalytic activity. Meanwhile, when the loading of the active component is less than 3%, the content of the active component of the catalyst is low, the service life is short, and when the loading of the active component is more than 30%, the active component is easy to agglomerate and block the pores of the catalyst, so that the porosity of the catalyst is greatly reduced, and the productivity of vinyl chloride is reduced. The catalyst has the advantages of high activity, low cost and long service life.

More preferably, the copper chloride is copper chloride, the mechanical strength of the carrier is 93-98%, and the saturated water absorption of the carrier is 20-70%.

By adopting the technical scheme, the copper chloride is of a deformed cadmium iodide structure, most of copper (II) compounds deviate from an ideal octahedral structure due to the ginger-Taylor effect, but the whole copper (II) compounds still show the octahedral structure, and when the copper chloride is loaded on the carrier, the copper chloride and active sites in the carrier perform ion exchange to form a complex, and then the complex can be stably combined in pores of the carrier. The mechanical strength of the carrier is between 93 and 98 percent, when the mechanical strength of the carrier is less than 93 percent, the carrier is easy to break in the long-term use process and influences the service life of the catalyst, and when the mechanical strength of the carrier is more than 98 percent, the porosity of the carrier is reduced, the adsorption and dispersion of active components in the pores of the carrier are influenced, and the activity of the catalyst is reduced.

More preferably, the support is a columnar support, and the columnar support is activated carbon particles.

More preferably, the average diameter of the columnar carrier is 3.0-4.5mm, the average length is 4-9mm, and the specific surface area is 700-1200m²/g。

By adopting the technical scheme, the catalyst is added into the fixed bed reactor, and is stacked in the fixed bed reactor to form a channel. The mixed gas of acetylene and hydrogen chloride enters a fixed bed reactor and reacts under the catalysis of a catalyst to generate vinyl chloride. When the diameter of the carrier in the catalyst is less than 3.0mm, the resistance of the mixed gas is increased, the flow rate of the mixed gas is reduced, and the productivity of vinyl chloride is reduced. When the diameter of the carrier in the catalyst is more than 4.5mm, the diffusion time of the mixed gas is prolonged, and the productivity of vinyl chloride is reduced. When the length of the catalyst is more than 9mm, the catalyst is easy to form a bridge in the fixed bed reactor, namely, the mixed gas forms a short circuit in the fixed bed reactor, so that the contact area of the mixed gas and the catalyst is reduced, and the catalytic effect of the catalyst is reduced.

More preferably, the carrier is a spherical carrier, and the spherical carrier is a silica gel particle.

More preferably, the spherical carrier has an average particle size of 3.5 to 6.0mm and a specific surface area of 200-600m²/g。

By adopting the technical scheme, the catalyst is added into the fixed bed reactor, and is stacked in the fixed bed reactor to form a channel. The mixed gas of acetylene and hydrogen chloride enters a fixed bed reactor and reacts under the catalysis of a catalyst to generate vinyl chloride. The carrier is a spherical carrier, so the catalyst is a spherical catalyst, and compared with a columnar catalyst, the spherical catalyst reduces the contact area among spherical catalysts and between the spherical catalyst and the inner side wall of the fixed bed reactor, increases the contact area between the spherical catalyst and mixed gas, further increases the contact area between an active component and the mixed gas, and improves the catalytic activity and the service life of the catalyst. Moreover, the silica gel particles are of a skeleton structure, contain a large amount of communicated macropores inside, have good adsorption performance, enable active components to be uniformly loaded on a carrier, and meanwhile, the silica gel particles also have good mechanical strength, do not generate dust in the production process of the catalyst, and are simple and convenient to prepare.

The second aim of the invention is realized by the following technical scheme:

a process for preparing mercury-free catalyst from vinyl chloride in industry features that the active component is loaded on the carrier by isovolumetric immersion method or excess immersion method by gas stirring.

By adopting the technical scheme and adopting a gas stirring mode, the active component is uniformly loaded on the carrier, so that the activity of the catalyst is improved and the service life of the catalyst is prolonged.

More preferably, an excess impregnation method is adopted, and specifically comprises the following steps:

a1, preparing the active components into a solution to obtain a precursor solution, wherein the temperature of the precursor solution is 35-80 ℃;

a2, placing the precursor solution in a carrier, contacting the precursor solution with the carrier, absorbing the precursor solution by the carrier, wherein the volume of the precursor solution is 0.5-3.0 times of the volume of the carrier;

a3, introducing gas into the precursor solution to turn the carrier in the precursor solution for 300min, wherein the turning time is 200-;

a4, stopping introducing gas into the precursor solution, settling the carrier in the precursor solution, standing for 30-40min, and separating to obtain a primary finished product;

a5, drying the primary product at 100-170 ℃ for 13-16h to obtain the catalyst.

By adopting the technical scheme, when the carrier absorbs water, the active component enters the carrier along with the water, and carries out ion exchange on the surface of the carrier, and forms a complex compound in pores of the stably combined carrier. The concentration of the active component near the carrier is reduced due to the influence of the carrier, namely, the concentration of the active component in the precursor solution is uneven due to the influence of the adsorption of the carrier, so that the distribution of the active component in the carrier is influenced. Meanwhile, the temperature of the precursor solution is 35-80 ℃, the Brownian motion of the active components in the precursor solution is increased, the active components can conveniently enter the pores of the carrier, and the uniformity of the active components in the pores of the carrier is also improved.

More preferably, the method of the equal-volume impregnation comprises the following steps:

s1, preparing the active components into a solution to obtain a precursor solution, wherein the temperature of the precursor solution is 35-80 ℃;

s2, placing the carrier in a mixing container, introducing gas into the mixing container, and turning over the carrier in the mixing container;

s3, introducing a precursor solution into the mixing container, introducing the precursor solution into the mixing container for multiple times, wherein the time interval between the introduction of the precursor solution in two adjacent times is 40-60min, the introduction of the precursor solution is finished within 240min after 160-one times, and when the precursor solution enters the mixing container, the precursor solution is contacted with the carrier and is absorbed by the carrier;

s4, stopping introducing gas into the mixing container after the precursor solution is introduced, settling the carrier at the bottom of the mixing container, and standing for 40-60min to obtain a primary finished product;

s5, drying the primary product at the drying temperature of 100 ℃ and 170 ℃ for 13-16h to obtain the catalyst.

By adopting the technical scheme, when the carrier absorbs water, the active component enters the carrier along with the water, and carries out ion exchange on the surface of the carrier, and forms a complex compound in pores of the stably combined carrier. The carrier has a certain time when adsorbing the precursor solution, but not one-time rapid adsorption, in the application, the precursor solution is introduced into the mixing container for multiple times and is contacted with the carrier, and the introduction time interval of two adjacent precursor solutions is 40-60min, so that the carrier can conveniently adsorb the precursor solution. Meanwhile, a gas stirring mode is adopted in the method, so that the carrier is turned in the mixing container, the contact area between the carrier and the precursor solution is increased, the uniformity of the active component in the carrier is increased, the activity of the catalyst is improved, and the service life of the catalyst is prolonged.

The third object of the invention is realized by the following technical scheme:

the industrial mercury-free catalyst for synthesizing vinyl chloride with vinyl chloride is composed of at least two serially connected reactor groups, and the catalysts filled in said reactor groups.

By adopting the technical scheme, the reactor group positioned at the most downstream is filled with the new catalyst, and the reactor group positioned at the upstream is filled with the old catalyst replaced at the downstream, so that the recycling of the catalyst is realized, the service life of the catalyst is prolonged, and the production cost of vinyl chloride is reduced.

In conclusion, the invention has the following beneficial effects:

first, the industrial mercury-free catalyst synthesized by vinyl chloride of the present application has the advantages of high activity, low cost and long service life.

Secondly, the catalyst is a columnar carrier, the granularity of the columnar carrier is limited, the yield of vinyl chloride is reduced due to the fact that the granularity of the catalyst is too small or too large, the length of the catalyst is also reduced to be too large, bridging is formed among the catalysts, short circuit is formed among mixed gas, and the catalytic effect of the catalyst is reduced. The catalyst is a spherical carrier, the spherical catalyst increases the contact area between the spherical catalyst and mixed gas, and improves the catalytic activity and the service life of the catalyst.

Thirdly, the preparation method of the mercury-free catalyst synthesized by vinyl chloride in the industry adopts a gas stirring mode to uniformly load the active component on the carrier, thereby improving the activity and prolonging the service life of the catalyst.

And fourthly, the catalyst is prepared by adopting a gas stirring and excess impregnation method, so that the concentration of active components in the precursor solution is uniform, the uniformity of the active components in the carrier is improved, the activity of the catalyst is improved, and the service life of the catalyst is prolonged. This application adopts gas stirring and isometric immersion method to prepare the catalyst, has increased the area of contact between carrier and the precursor solution, increases the degree of consistency of active ingredient in the carrier, improves the activity and the life of catalyst, and precursor solution divides the contact with the carrier many times simultaneously, and the carrier of being convenient for is to the absorption of precursor solution, the preparation of the catalyst of being convenient for.

Fifth, the preparation method for synthesizing the mercury-free catalyst by using vinyl chloride in the industry realizes the recycling of the catalyst and reduces the production cost of vinyl chloride.

Detailed Description

The present invention will be described in further detail with reference to examples.