Oxychlorination catalyst, process for its preparation and use

Abstract

This application relates to the field of catalyst technology, specifically to an oxychlorination catalyst and its preparation method, and particularly to the application of this catalyst in the oxychlorination fluidized bed process of ethylene. The oxychlorination catalyst described in this application is an alumina-supported catalyst. By controlling the range of sodium content in the raw materials and adjusting the ratio of catalyst acidity on the low-temperature side (100-262℃) to catalyst acidity on the high-temperature side (262-400℃) in the ammonia-temperature desorption method to between 0.5 and 3.5, the oxychlorination catalyst exhibits high activity and high stability, and can be used in the technical field of oxychlorination of ethylene to produce dichloroethane.

Description

Technical Field

[0001] This application relates to the field of catalyst technology, specifically to an oxychlorination catalyst and its preparation method, and particularly to the application of the catalyst in the ethylene oxychlorination fluidized bed process. Background Technology

[0002] Polyvinyl chloride (PVC) is polymerized from vinyl chloride monomer and is one of the five major general-purpose resins. Currently, the mainstream production process for vinyl chloride involves the oxychlorination of ethylene to produce dichloroethane, followed by the cracking of dichloroethane to obtain vinyl chloride. Since oxychlorination is an exothermic reaction, a fluidized bed process is advantageous to dissipate the reaction heat promptly. This process involves the gas-phase reaction of ethylene, hydrogen chloride, and a mixture of oxygen or oxygen-containing gas in a fluidized bed. The key to this process is the development of a highly active and selective ethylene oxychlorination catalyst.

[0003] Currently, the oxychlorination catalysts traditionally used in industry are mainly single-component copper alumina catalysts. These catalysts have high HCl conversion rates and good selectivity for dichloroethane. However, these catalysts suffer from problems such as easy loss of active components, stickiness, and high CO and CO2 content in the byproducts of ethylene combustion. Therefore, there is a need in the field to develop a highly active and stable catalyst that can improve catalyst activity and suppress the volatilization of active components, especially a catalyst with a simple preparation process, low reaction temperature, high activity, and high stability. Summary of the Invention

[0004] This application provides an oxychlorination catalyst, which has the advantages of low reaction temperature, high reaction activity, low copper loss and high stability, and can be used in the process of oxychlorination of ethylene to produce dichloroethane.

[0005] This application also provides a method for preparing the above-mentioned oxychlorination catalyst, which has the advantage of simple preparation process.

[0006] This application also provides the application of the above-mentioned oxychlorination catalyst in the ethylene oxychlorination fluidized bed process, which has the advantage of high reaction yield.

[0007] In a first aspect, this application provides an oxychlorination catalyst having the features shown in items (a)-(b) below:

[0008] (a) The ratio X of the amount of catalyst acid on the low-temperature side (100-262°C) as determined by the ammonia heating desorption method to the amount of catalyst acid on the high-temperature side (262-400°C) as determined by the ammonia heating desorption method is 0.5-3.5;

[0009] (b) The catalyst includes a support in which the content of the metal element Na, Y, is 10ppm-1000ppm.

[0010] In an alternative embodiment, the catalyst further has the feature shown in item (c):

[0011] (c) The ratio X of the catalyst acidity on the low-temperature side (100-262°C) determined by the ammonia heating desorption method to the catalyst acidity on the high-temperature side (262-400°C) determined by the ammonia heating desorption method, and the ratio X / Y of the Na content value in the catalyst, is 30-45000.

[0012] In one optional embodiment, the catalyst comprises a support and an active element supported on the support; wherein,

[0013] The carrier includes an alumina carrier;

[0014] The active element includes one or more of copper, alkali metals, or alkaline earth metals.

[0015] In one optional embodiment, the copper element in the active element has a mass content of 1-15 wt% based on the total mass of the catalyst;

[0016] Preferably, the copper content is 2-12 wt%, more preferably 3-8 wt%.

[0017] In one optional embodiment, the alkali metal element in the active element comprises 0.2-5 wt% based on the total mass of the catalyst;

[0018] Preferably, the alkali metal content is 0.25-4 wt%, more preferably 0.3-3.5 wt%;

[0019] Preferably, the alkali metal element includes one or both of potassium or sodium.

[0020] In one optional embodiment, the alkaline earth metal element in the active element has a mass content of 0.5-10 wt% based on the total mass of the catalyst;

[0021] Preferably, the content of the alkaline earth metal is 0.8-9 wt%, more preferably 1-8 wt%;

[0022] Preferably, the alkaline earth metal element includes one or more of magnesium, calcium, or strontium.

[0023] In one optional embodiment, the active element in the oxychlorination catalyst further includes one or more of the following elements: iron, lanthanum, samarium, neodymium, cerium, and titanium.

[0024] Secondly, this application also provides a method for preparing the oxychlorination catalyst, comprising the following steps:

[0025] S1: According to the selected content, take the salt containing the selected active element, add it to the acid solution and mix to prepare the active loading solution;

[0026] S2: Take a selected carrier and contact it with the active loading liquid phase to obtain a precursor;

[0027] S3. Dry the precursor to obtain the final product.

[0028] In an optional embodiment, in S1, the active loading solution contains:

[0029] The acid solution includes one or more of nitric acid, hydrochloric acid, or phosphoric acid; and / or,

[0030] The salt of the active element includes the inorganic salt of the active element, preferably one or more of nitrate, chloride, or carbonate.

[0031] In one optional embodiment, the oxychlorination catalyst is prepared by:

[0032] S2 further includes a step of allowing the precursor to stand for 1-8 hours; and / or,

[0033] In step S3, the temperature of the drying step is 50-300℃.

[0034] Thirdly, this application also provides the application of the oxychlorination catalyst or the oxychlorination catalyst prepared by the method in the process of oxychlorination of ethylene to dichloroethane.

[0035] Preferably, the process for preparing dichloroethane by oxychlorination of ethylene includes a fluidized bed reactor process.

[0036] The oxychlorination catalyst described in this application uses an alumina-supported catalyst, especially a Cu-based catalyst. By controlling the range of sodium content in the raw materials and adjusting the ratio of the catalyst acid content on the low-temperature side (100-262℃) to the catalyst acid content on the high-temperature side (262-400℃) in the ammonia desorption method to be between 0.5 and 3.5, the oxychlorination catalyst exhibits high activity and high stability, and can be used in the technical field of oxychlorination of ethylene to prepare dichloroethane. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0041] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0042] In order to improve the activity of oxychlorination catalysts and suppress the volatilization of active components, thereby obtaining oxychlorination catalysts with high catalytic activity and high stability, this application provides an oxychlorination catalyst having the characteristics shown in items (a)-(b) below:

[0043] (a) The ratio X of the amount of catalyst acid on the low-temperature side (100-262°C) as determined by the ammonia heating desorption method to the amount of catalyst acid on the high-temperature side (262-400°C) as determined by the ammonia heating desorption method is 0.5-3.5;

[0044] (b) The catalyst includes a support in which the content of the metal element Na, Y, is 10ppm-1000ppm.

[0045] In its research on catalysts for the oxychlorination of ethylene to produce dichloroethane, this application discovered that for Cu-based catalysts using alumina as a support, not only does the sodium content affect catalyst performance, but the ratio of the acid content on the low-temperature side (100-262°C) to the acid content on the high-temperature side (262-400°C), as determined by the ammonia-induced desorption method, also influences catalyst performance. The oxychlorination catalyst described in this application, by controlling the sodium content in the supported active element within the range of 10 ppm to 1000 ppm, exhibits high activity and high stability.

[0046] In an optional embodiment, the oxychlorination catalyst of this application further has the features shown in item (c):

[0047] (c) The ratio X of the catalyst acidity on the low-temperature side (100-262°C) determined by the ammonia heating desorption method to the catalyst acidity on the high-temperature side (262-400°C) determined by the ammonia heating desorption method, and the ratio X / Y of the Na content value in the catalyst, is 30-45000.

[0048] The catalyst used in the process of oxychlorination of ethylene to produce dichloroethane has the characteristics of high activity and high stability when the ratio of the amount of catalyst acid on the low-temperature side (100-262°C) to the amount of catalyst acid on the high-temperature side (262-400°C) is adjusted to be between 0.5 and 3.5 in the ammonia-induced desorption method.

[0049] In one optional embodiment, the sodium content Y in the supported active element of the oxychlorination catalyst of this application is adjusted to be in the range of 10ppm-1000ppm. As an exemplary embodiment, the loading of Na element in the catalyst can be adjusted to 10ppm, 100ppm, 200ppm, 300ppm, 500ppm, 600ppm, 800ppm, 1000ppm, etc., or within any range of the above values.

[0050] In one optional embodiment, the ratio X of the oxychlorination catalyst described in this application in the ammonia temperature desorption method is adjusted to be between 0.5 and 3.5, specifically the ratio of the amount of catalyst acid on the low-temperature side (100-262°C) to the amount of catalyst acid on the high-temperature side (262-400°C). As an exemplary embodiment, the ratio X is adjusted to 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.3, 2.5, 2.8, 3.0, 3.2, 3.5, etc., or within any range of the above values.

[0051] In an optional embodiment, in the oxychlorination catalyst of this application, the ratio X of the catalyst acid content on the low-temperature side (100-262°C) determined by the ammonia-heated desorption method to the catalyst acid content on the high-temperature side (262-400°C) determined by the ammonia-heated desorption method, and the ratio of the Na content value in the catalyst, are further adjusted to 30-45000. Based on the aforementioned preferred range of X and Y values, the performance of the catalyst is further optimized by optimizing the ratio of these two parameters. As an exemplary implementation, based on the aforementioned preferred range of X and Y values, the X / Y ratio can be further adjusted to 30, 100, 200, 500, 800, 1000, 1500, 2000, 2500, 3000, 5000, 8000, 10000, 12000, 15000, 18000, 20000, 25000, 30000, 35000, 40000, 45000, etc., or fall within any range of the above values.

[0052] In one optional embodiment, the catalyst comprises a support and an active element supported on the support; wherein,

[0053] The carrier includes an alumina carrier; as an exemplary embodiment, in addition to the Na element content value Y, the specific surface area of ​​the alumina carrier is further preferably 100-300 μm. 2 / g, pore size 3-15nm, volume average particle size 30-80μm;

[0054] The active element includes one or more of copper, alkali metals, or alkaline earth metals.

[0055] The oxychlorination catalyst described in this application is preferably an alumina-supported Cu-based catalyst. It has high activity and low copper loss in the oxychlorination of ethylene to dichloroethane reaction, and can stably obtain dichloroethane in high yield.

[0056] In one optional embodiment, the oxychlorination catalyst of this application contains 1-15 wt% copper as an active element, based on the total amount of the catalyst. As an exemplary embodiment, the content of Cu in the catalyst is adjusted to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 wt%, or within any range of the above values. Preferably, the content of copper is 2-12 wt%, more preferably 3-8 wt%.

[0057] In one optional embodiment, the alkali metal content in the oxychlorination catalyst, based on the total amount of the catalyst, is 0.2-5 wt%. As an exemplary embodiment, the alkali metal content in the catalyst can be adjusted to 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 wt%, or within any range of the above values. Preferably, the alkali metal content is 0.25-4 wt%, more preferably 0.3-3.5 wt%.

[0058] In one alternative embodiment, the alkali metal element in the oxychlorination catalyst includes one or both of potassium and sodium.

[0059] In one optional embodiment, the alkaline earth metal element content in the oxychlorination catalyst, based on the total amount of the catalyst, is 0.5-10 wt%. As an exemplary embodiment, the alkaline earth metal element content in the catalyst is adjusted to 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 wt%, or within any range of the above values. Preferably, the alkaline earth metal content is 0.8-9 wt%, more preferably 1-8 wt%.

[0060] In one alternative embodiment, the alkaline earth metal element in the oxychlorination catalyst includes one or more of magnesium, calcium, or strontium.

[0061] In one optional embodiment, the active element in the oxychlorination catalyst further includes one or more of the following elements: iron, lanthanum, samarium, neodymium, cerium, and titanium.

[0062] Secondly, this application also provides a method for preparing the oxychlorination catalyst, comprising the following steps:

[0063] S1: According to the selected content, take the salt containing the selected active element, add it to the acid solution and mix to prepare the active loading solution;

[0064] S2: Take a selected carrier and contact it with the active loading liquid phase to obtain a precursor;

[0065] S3. Dry the precursor to obtain the final product.

[0066] In an optional embodiment, in S1, the active loading solution contains:

[0067] The acid solution includes one or more of nitric acid, hydrochloric acid, or phosphoric acid; and / or,

[0068] The salt of the active element includes the inorganic salt of the active element, preferably one or more of nitrates, chlorides, or carbonates.

[0069] In one optional implementation, step S2 further includes a step of letting the precursor stand for 1-8 hours. As an exemplary implementation, the precursor is controlled to stand for 1, 2, 3, 4, 5, 6, 7, 8 hours, or within any range of the above values.

[0070] In one optional embodiment, in step S3, the temperature of the drying step is 50-300°C. As an exemplary embodiment, the drying temperature is controlled to be 50, 100, 150, 200, 250, 300°C, or within any range of the above values.

[0071] Thirdly, this application also provides the application of the oxychlorination catalyst or the oxychlorination catalyst prepared by the method in the process of oxychlorination of ethylene to dichloroethane.

[0072] Preferably, the process for preparing dichloroethane by oxychlorination of ethylene includes a fluidized bed reactor process.

[0073] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0074] In the following embodiments and comparative examples of this application, the alumina carrier was purchased from Zibo Chaoke Alumina Materials Co., Ltd., and other raw materials and reagents were purchased from commercially available sources unless otherwise specified.

[0075] In the following embodiments of this application, for example, the specific surface area of ​​the alumina carrier is selected to be 100-300 μm. 2 / g, pore size 3-15nm, volume average particle size 30-80um, the Na content in the carrier is selected according to the need to select an appropriate alumina carrier product.

[0076] Example 1

[0077] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 5 wt%, potassium 0.2 wt%, magnesium 1 wt%, lanthanum 1 wt%, and cerium 3 wt%.

[0078] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0079] S1: Weigh 261.06g of copper nitrate, 35.17g of lanthanum chloride, 105g of cerium chloride, 5.28g of potassium chloride, and 54.18g of magnesium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0080] S2: Take 1800g of alumina carrier (sodium content is 100ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 2 hours.

[0081] S3: Dry the precursor thoroughly at 260°C to obtain the final product.

[0082] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0083] Example 2

[0084] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 8 wt%, potassium 4 wt%, magnesium 1 wt%, calcium 2 wt%, and neodymium 1 wt%.

[0085] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0086] S1: Weigh out 335.84g of copper chloride, 47.75g of neodymium nitrate, 120.14g of potassium chloride, 61.55g of magnesium chloride, and 128.9g of calcium nitrate, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0087] S2: Take 1800g of alumina carrier (sodium content is 800ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 7h.

[0088] S3: The precursor is thoroughly dried at 160°C to obtain the final product.

[0089] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0090] Example 3

[0091] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 4 wt%, potassium 0.3 wt%, magnesium 5 wt%, calcium 2 wt%, and samarium 0.5 wt%.

[0092] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0093] S1: Weigh out 174.99g of copper chloride, 24.2g of samarium nitrate, 9.39g of potassium chloride, 320.71g of magnesium chloride, and 134.34g of calcium nitrate, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0094] S2: Take 1800g of alumina carrier (sodium content is 60ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 5h.

[0095] S3: Dry the precursor thoroughly at 90°C for 8 hours to obtain the final product.

[0096] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0097] Example 4

[0098] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 2 wt%, potassium 3.5 wt%, magnesium 0.5 wt%, lanthanum 1 wt%, and cerium 2 wt%.

[0099] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0100] S1: Weigh out 103.65g of copper nitrate, 34.92g of lanthanum chloride, 69.48g of cerium chloride, 91.85g of potassium chloride, and 26.89g of magnesium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0101] S2: Take 1800g of alumina carrier (sodium content is 300ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 1h.

[0102] S3: Dry the precursor at 300°C for 8 hours to obtain the final product.

[0103] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0104] Example 5

[0105] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 1 wt%, potassium 0.5 wt%, magnesium 0.5 wt%, strontium 0.3 wt%, lanthanum 1 wt%, and cerium 2 wt%.

[0106] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0107] S1: Weigh out 34.03g of copper chloride, 32.40g of lanthanum chloride, 78.95g of cerium nitrate, 12.17g of potassium chloride, 24.95g of magnesium chloride, and 9.23g of strontium nitrate, respectively, dissolve them in 702g of water, and add 100g of 65% nitric acid to mix thoroughly to obtain the active loading solution for later use;

[0108] S2: Take 1800g of alumina carrier (sodium content is 1000ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 8h.

[0109] S3: Dry the precursor at 50°C for 8 hours to obtain the final product.

[0110] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0111] Example 6

[0112] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 3 wt%, potassium 5 wt%, strontium 5 wt%, calcium 4 wt%, titanium 1 wt%, and cerium 2 wt%.

[0113] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0114] S1: Weigh out 131.69g of copper chloride, 101.83g of cerium nitrate, 102.94g of titanium nitrate, 157.03g of potassium chloride, 182.34g of calcium chloride, and 198.41g of strontium nitrate, respectively, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0115] S2: Take 1800g of alumina carrier (sodium content is 20ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 2 hours.

[0116] S3: Dry the precursor at 150°C for 8 hours to obtain the final product.

[0117] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0118] Example 7

[0119] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 12 wt%, potassium 0.25 wt%, strontium 5 wt%, calcium 5 wt%, lanthanum 1 wt%, and cerium 2 wt%.

[0120] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0121] S1: Weigh out 551.9g of copper chloride, 53.66g of lanthanum nitrate, 106.69g of cerium nitrate, 8.23g of potassium chloride, 238.8g of calcium chloride, and 207.88g of strontium nitrate, respectively, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0122] S2: Take 1800g of alumina carrier (sodium content is 12ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 2 hours.

[0123] S3: Dry the precursor at 150°C for 8 hours to obtain the final product.

[0124] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0125] Example 8

[0126] The oxychlorination catalyst described in this embodiment uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 10 wt%, potassium 2.5 wt%, strontium 0.5 wt%, magnesium 0.3 wt%, lanthanum 1 wt%, and cerium 2 wt%.

[0127] S1: Weigh out 404.28g of copper chloride, 47.17g of lanthanum nitrate, 93.78g of cerium nitrate, 72.31g of potassium chloride, 17.78g of magnesium chloride, and 18.27g of strontium nitrate, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0128] S2: Take 1800g of alumina carrier (sodium content is 500ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 2 hours.

[0129] S3: Dry the precursor at 150°C for 8 hours to obtain the final product.

[0130] The oxychlorination catalyst described in this embodiment was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0131] Comparative Example 1

[0132] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 5 wt%, potassium 2 wt%, magnesium 5 wt%, calcium 2 wt%, lanthanum 1.5 wt%, and cerium 1.5 wt%.

[0133] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0134] S1: Weigh out 345.41g of copper nitrate, 69.81g of lanthanum chloride, 69.46g of cerium chloride, 69.96g of potassium chloride, 358.43g of magnesium chloride, and 150.14g of calcium nitrate, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0135] S2: Take 1800g of alumina carrier (sodium content is 200000ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 7h.

[0136] S3: Dry the precursor at 180°C for 8 hours to obtain the product.

[0137] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0138] Comparative Example 2

[0139] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 5 wt%, potassium 2 wt%, magnesium 5 wt%, calcium 2 wt%, lanthanum 1.5 wt%, and cerium 1.5 wt%.

[0140] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0141] S1: Weigh out 345.41g of copper nitrate, 69.81g of lanthanum chloride, 69.46g of cerium chloride, 69.96g of potassium chloride, 358.43g of magnesium chloride, and 150.14g of calcium nitrate, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0142] S2: Take 1800g of alumina carrier (sodium content is 0.9ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 6h.

[0143] S3: Dry the precursor at 280°C for 3 hours to obtain the product.

[0144] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0145] Comparative Example 3

[0146] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 7 wt%, potassium 1 wt%, magnesium 1 wt%, calcium 3 wt%, and lanthanum 1 wt%.

[0147] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0148] S1: Weigh out 386.26g of copper nitrate, 37.18g of lanthanum chloride, 27.94g of potassium chloride, 57.26g of magnesium chloride, and 121.67g of calcium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0149] S2: Take 1800g of alumina carrier (sodium content is 200ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 5h.

[0150] S3: Dry the precursor at 150°C for 6 hours to obtain the final product.

[0151] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0152] Comparative Example 4

[0153] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 2 wt%, potassium 3 wt%, magnesium 6 wt%, and lanthanum 1 wt%.

[0154] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0155] S1: Weigh out 93.19g of copper chloride, 54.37g of lanthanum nitrate, 100.01g of potassium chloride, and 409.9g of magnesium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0156] S2: Take 1800g of alumina carrier (sodium content is 200ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 5h.

[0157] S3: Dry the precursor at 150°C for 6 hours to obtain the final product.

[0158] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0159] Comparative Example 5

[0160] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 4 wt%, potassium 1.5 wt%, calcium 3 wt%, and cerium 2 wt%.

[0161] The preparation method of the oxychlorination catalyst described in this comparative example includes the following steps:

[0162] S1: Weigh 206.7g copper nitrate, 69.28g cerium chloride, 39.25g potassium chloride, and 113.94g calcium chloride respectively, dissolve them in 702g water, and add 100g of 65% nitric acid to mix thoroughly to obtain the active loading solution for later use;

[0163] S2: Take 1800g of alumina carrier (sodium content is 20ppm) and immerse it fully in the active loading solution, then let the immersed precursor stand for 6h.

[0164] S3: Dry the precursor at 120°C for 6 hours to obtain the final product.

[0165] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0166] Comparative Example 6

[0167] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 3 wt%, potassium 1 wt%, magnesium 6 wt%, calcium 2%, lanthanum 1 wt%, and samarium 4%.

[0168] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0169] S1: Weigh out 150.73g of copper chloride, 222.35g of samarium nitrate, 58.62g of lanthanum nitrate, 35.94g of potassium chloride, 441.98g of magnesium chloride, and 104.35g of calcium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0170] S2: Take 1800g of alumina carrier (sodium content is 0.1%) and immerse it fully in the active loading solution, then let the immersed precursor stand for 4h.

[0171] S3: Dry the precursor at 270°C for 5 hours to obtain the product.

[0172] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0173] Comparative Example 7

[0174] The oxychlorination catalyst described in this comparative example uses alumina as a support and is loaded with the following active elements in the following amounts (based on the total amount of the catalyst): copper 9 wt%, potassium 0.5 wt%, calcium 6 wt%, and lanthanum 1 wt%.

[0175] The preparation method of the oxychlorination catalyst described in this embodiment includes the following steps:

[0176] S1: Weigh out 508.25g of copper nitrate, 38.04g of lanthanum chloride, 14.30g of potassium chloride, and 249.04g of calcium chloride, dissolve them in 702g of water, and add 100g of 65% nitric acid. Mix thoroughly to obtain the active loading solution for later use.

[0177] S2: Take 1800g of alumina carrier (sodium content is 0.15%) and immerse it fully in the active loading solution, then let the immersed precursor stand for 2 hours;

[0178] S3: Dry the precursor at 120°C for 7 hours to obtain the final product.

[0179] The oxychlorination catalyst described in this comparative example was subjected to elemental analysis using ICP testing, and its elemental content met the design requirements.

[0180] Experimental Example

[0181] 1. Catalyst characterization and performance testing

[0182] The catalysts prepared in the above examples and comparative examples were characterized by NH3-TPD. The ratio X of the amount of catalyst acid at low temperature (100-262℃) to the amount of catalyst acid at high temperature (262-400℃) was detected, and the X / Y result was calculated based on the Na content Y in each catalyst.

[0183] Characterization method for catalytic ammonia temperature-programmed desorption (NH3-TPD): The acid content of the catalyst was determined using an ammonia temperature-programmed desorption apparatus. 0.2 g of catalyst was accurately weighed and placed in a quartz sample cell. The sample cell was pretreated by heating to 500 °C and holding at that temperature for 5 h under an argon atmosphere. Then, the sample cell was cooled to 50 °C to adsorb ammonia until saturation. Following this, vacuum degassing was performed at 50 °C for 30 min. Subsequently, the sample cell was temperature-programmed to 600 °C under an argon atmosphere at a heating rate of 10 °C / min, and the amount of ammonia desorbed was measured.

[0184] The characterization results of each catalyst parameter in this experimental example are recorded in Table 1 below.

[0185] Table 1 Characterization of catalyst parameters

[0186] serial number X value Na content value Y / % X / Y Example 1 0.6 0.0001 6000 Example 2 2.8 0.0008 3500 Example 3 2.5 0.00006 41666 Example 4 0.3 0.0003 1000 Example 5 3 0.001 3000 Example 6 0.5 0.00002 25000 Example 7 0.5 0.000012 41667 Example 8 1 0.0005 2000 Comparative Example 1 3.5 0.2 17.5 Comparative Example 2 0.5 0.0000009 555556 Comparative Example 3 4 0.0002 20000 Comparative Example 4 0.1 0.0002 500 Comparative Example 5 3 0.00002 150000 Comparative Example 6 2 0.1 20 Comparative Example 7 6 0.15 40

[0187] As can be seen, the performance of the Cu-based catalyst supported on alumina in this application is affected not only by the sodium content in the support, but also by the ratio of the acid content of the catalyst on the low-temperature side (100-262℃) to that on the high-temperature side (262-400℃), as determined by the ammonia desorption method. The oxychlorination catalyst in this application effectively ensures high activity and high stability by controlling the sodium content in the supported active element within the range of 10ppm-1000ppm and by controlling the ratio X value of the acid content on the low-temperature side (100-262℃) to that on the high-temperature side (262-400℃), as determined by the ammonia desorption method.

[0188] 2. Catalytic performance test

[0189] The catalyst activity was evaluated according to the catalyst performance testing methods in the aforementioned experimental examples and comparative examples. After continuous reaction for 100 h and 1000 h, the HCl conversion rate and dichloroethane selectivity were measured.

[0190] Catalyst performance testing method: 1 kg of catalyst was placed in a fluidized bed reactor with an inner diameter of 40 mm and a height of 1700 mm, using ethylene / hydrogen chloride / oxygen as feedstock, and the feed space velocity was 600 h⁻¹. -1 The oxychlorination of ethylene was carried out at a reaction temperature of 210-270℃ and a reaction pressure of 0.3MPa (absolute pressure). During the catalyst reaction performance test, samples were taken three times every 24 hours for analysis.

[0191] The performance test results of each catalyst in this experiment are recorded in Table 2 below.

[0192] Table 2 Catalytic performance test results

[0193]

[0194] As can be seen, the oxychlorination catalyst described in this application is an alumina-supported Cu-based catalyst. By controlling the range of sodium content in the raw materials and adjusting the ratio of the catalyst acid content on the low-temperature side (100-262℃) to the catalyst acid content on the high-temperature side (262-400℃) in the ammonia-heated desorption method to be between 0.5 and 3.5, the oxychlorination catalyst exhibits high activity. In particular, its catalyst activity remains good after long-term operation, demonstrating high stability. It can be used in the technical field of oxychlorination of ethylene to prepare dichloroethane.

[0195] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. An oxychlorination catalyst, characterized in that, The catalyst has the characteristics shown in items (a)-(b) below: (a) The ratio X of the amount of catalyst acid on the low-temperature side (100-262°C) as determined by the ammonia heating desorption method to the amount of catalyst acid on the high-temperature side (262-400°C) as determined by the ammonia heating desorption method is 0.5-3.5; (b) The catalyst includes a support in which the content of the metal element Na, Y, is 10ppm-1000ppm.

2. The oxychlorination catalyst according to claim 1, characterized in that, The catalyst also has the following characteristic as shown in item (c): (c) the ratio X of the catalyst acid content on the low-temperature side (100-262°C) determined by the ammonia heating desorption method to the catalyst acid content on the high-temperature side (262-400°C) determined by the ammonia heating desorption method to the Na content value Y in the catalyst is 30-45000.

3. The oxychlorination catalyst according to claim 1 or 2, characterized in that, The catalyst comprises the support and an active element supported on the support; wherein, The carrier includes an alumina carrier; The active element includes one or more of copper, alkali metals, or alkaline earth metals.

4. The oxychlorination catalyst according to claim 3, characterized in that, Of the active elements, the copper element has a mass content of 1-15 wt% based on the total mass of the catalyst; Preferably, the copper content is 2-12 wt%, more preferably 3-8 wt%.

5. The oxychlorination catalyst according to claim 3, characterized in that, Of the active elements, the alkali metal element has a mass content of 0.2-5 wt% based on the total mass of the catalyst; Preferably, the alkali metal content is 0.25-4 wt%, more preferably 0.3-3.5 wt%; Preferably, the alkali metal element includes one or both of potassium or sodium.

6. The oxychlorination catalyst according to claim 3, characterized in that, Of the active elements, the alkaline earth metal element has a mass content of 0.5-10 wt% based on the total mass of the catalyst; Preferably, the content of the alkaline earth metal is 0.8-9 wt%, more preferably 1-8 wt%; Preferably, the alkaline earth metal element includes one or more of magnesium, calcium, or strontium.

7. The oxychlorination catalyst according to any one of claims 3-6, characterized in that, The active elements also include one or more of the following: iron, lanthanum, samarium, neodymium, cerium, and titanium.

8. A method for preparing an oxychlorination catalyst as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: According to the selected content, take the salt containing the selected active element, add it to the acid solution and mix to prepare the active loading solution; S2: Take a selected carrier and contact it with the active loading liquid phase to obtain a precursor; S3. Dry the precursor to obtain the final product.

9. The method for preparing the oxychlorination catalyst according to claim 8, characterized in that, In S1, the active loading solution contains: The acid solution includes one or more of nitric acid, hydrochloric acid, or phosphoric acid; and / or, The salt of the active element includes the inorganic salt of the active element, preferably one or more of nitrate, chloride, or carbonate.

10. The method for preparing the oxychlorination catalyst according to claim 8 or 9, characterized in that: S2 further includes a step of allowing the precursor to stand for 1-8 hours; and / or, In step S3, the temperature of the drying step is 50-300℃.

11. The application of the oxychlorination catalyst according to any one of claims 1-7 or the oxychlorination catalyst prepared by the method according to any one of claims 8-10 in the process of oxychlorination of ethylene to dichloroethane; Preferably, the process for preparing dichloroethane by oxychlorination of ethylene includes a fluidized bed reactor process.

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