Catalyst composition and method for treating C4-containing feedstock

Abstract

The invention relates to the field of processing of hydrocarbon raw materials, in particular to a catalyst composition and a processing method of a C4-containing raw material. The composition comprises a component A, a component B and a component C, wherein the component A is alumina loaded with hydrogenation active components; the component B is a ZSM-5 molecular sieve loaded with a modifying element, and the modifying element is selected from at least one of IIB group elements, IIIA group elements and VA group elements. According to the catalyst composition disclosed by the invention, the aluminum oxide loaded with the hydrogenation active component and the ZSM-5 molecular sieve loaded with the modified element are coupled, so that the catalytic effects of the aluminum oxide and the ZSM-5 molecular sieve are synergistically enhanced, and the catalytic performance of the catalyst composition is improved.

Description

Technical Field

[0001] The invention relates to the field of processing of hydrocarbon raw materials, and in particular to a catalyst composition and a method for processing raw materials containing carbon four. Background Art

[0002] In recent years, as domestic refining and chemical companies continue to optimize raw materials, cracking raw materials are developing in the direction of lightness, that is, from heavy cracking materials mainly based on naphtha to gas resources based on light hydrocarbons, petroleum gas, natural gas and other light hydrocarbons. The light raw material production route has the advantages of high yield of diene products, low cost, low energy consumption and low pollution. The diene yield of light raw materials is more than doubled compared to medium / heavy raw materials. For example, when light raw materials ethane and propane are cracked, the product is mainly ethylene, with a yield of more than 60%. The yield of propylene produced by propane dehydrogenation process is even higher, reaching more than 80%.

[0003] As a by-product of the refining unit, liquefied petroleum gas mainly contains C4 components, as well as a small amount of propane and components above C5. my country is rich in liquefied petroleum gas resources. In particular, with the rapid development of the new energy industry and the large-scale replacement of civilian liquefied gas by natural gas, liquefied petroleum gas resources are facing a large surplus. These light hydrocarbon resources have not been well utilized in my country and are mainly used as fuel, resulting in a huge waste of resources. The C4 component mainly contains isobutane, n-butane, n-butene, isobutene and a trace amount of butadiene. Due to the high olefin content in the composition, it cannot be directly used as a raw material for the cracking unit. Among the alkanes in the C4 raw material, there are more isoalkanes. When used as cracking materials, the diene yield is also relatively low. Therefore, C4 raw materials such as liquefied petroleum gas are not suitable as raw materials for cracking units.

[0004] With the expansion of the scale of cracking units in my country, the demand for light hydrocarbon resources is growing, and many methods have been used to produce cracking materials.

[0005] 201110143584.4 discloses a catalyst for producing propane and high-octane gasoline from butane, specifically a hydrogen-type medium-porous silica-alumina zeolite, and the propane yield can reach 25-55%.

[0006] CN112588314A discloses a catalyst for producing propane from light hydrocarbons and a preparation method thereof. The catalyst is a metal-loaded molecular sieve, which can efficiently convert light hydrocarbon raw materials such as liquefied gas and naphtha into propane, and the propane selectivity can reach more than 70%.

[0007] When the above methods are used to produce light hydrocarbons, the raw materials used are all alkanes and do not contain olefins. However, when using raw materials containing olefins to produce light hydrocarbons, the catalyst is easily deactivated and the light hydrocarbons obtained are relatively small.

[0008] The raw material for the ethylene cracking unit requires an olefin content of less than 2%, so the C4 raw material containing a large amount of olefins is not suitable for direct use as a raw material for the cracking unit. Summary of the invention

[0009] Liquefied petroleum gas and other C4 resources are relatively abundant in my country, but there are two main problems in using liquefied petroleum gas and other C4 resources to produce cracking materials: First, the raw materials contain a high level of olefins and cannot be directly used as cracking materials. Second, among the alkanes in the raw materials, the proportion of isoalkanes is relatively high, and when used as cracking materials, the yield of dienes is relatively low. Therefore, the purpose of the present invention is to provide a catalyst composition and a method for treating a C4-containing raw material in order to overcome the above problems. The catalyst composition and treatment method provided by the present invention can convert C4 raw materials such as liquefied petroleum gas into high-quality cracking materials ethane and propane with a higher yield.

[0010] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a catalyst composition, which comprises: component A: alumina loaded with hydrogenation active components; component B: ZSM-5 molecular sieve loaded with modifying elements, wherein the modifying elements are selected from at least one of Group IIB elements, Group IIIA elements and Group VA elements.

[0011] The second aspect of the present invention provides a method for treating a C4-containing raw material, the method comprising: contacting the C4-containing raw material with a catalyst under a hydrogen-containing atmosphere to obtain a diene cracking material; the catalyst comprises the composition described in the first aspect.

[0012] Through the above technical solution, the present invention has the following advantages:

[0013] The catalyst composition of the present invention couples alumina loaded with hydrogenation active components and ZSM-5 molecular sieve loaded with modification elements, thereby synergistically enhancing the catalytic effects of the two and improving the catalytic performance of the catalyst composition.

[0014] The catalyst composition of the present invention is used for treating raw materials containing C4 (such as liquefied petroleum gas), so that the raw materials can be efficiently converted into ethane and propane to obtain high-quality diene cracking materials. DETAILED DESCRIPTION

[0015] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0016] The present invention provides a catalyst composition, which comprises: component A: alumina loaded with hydrogenation active components; component B: ZSM-5 molecular sieve loaded with modifying elements, wherein the modifying elements are selected from at least one of group IIB elements, group IIIA elements and group VA elements.

[0017] The catalyst composition of the present invention couples the alumina loaded with hydrogenation active components and the molecular sieve loaded with modifying elements, thereby synergistically enhancing the catalytic effects of the two and improving the catalytic performance of the catalyst composition.

[0018] According to a preferred embodiment of the present invention, the content of the modifying element in the component B is 0.5-3 wt %. By adopting the above preferred solution, the catalytic performance of the composition can be further improved.

[0019] According to a preferred embodiment of the present invention, the modifying element comprises at least two of the Group VA elements, the Group IIB elements and the Group IIIA elements: when the Group VA elements are contained, the ratio of the total molar amount of the Group IIB elements and / or the Group IIIA elements to the molar amount of the Group VA elements is 1.5-3.0; when the Group VA elements are not contained, the ratio of the molar amount of the Group IIB elements to the Group IIIA elements is 0.1-5.0.

[0020] According to a preferred embodiment of the present invention, the Group IIB element is selected from Zn and / or Cd, preferably Zn.

[0021] According to a preferred embodiment of the present invention, the Group IIIA element is selected from Ga and / or In, preferably Ga.

[0022] According to a preferred embodiment of the present invention, the Group VA element is selected from at least one of P, As, and Sb, preferably P.

[0023] According to a preferred embodiment of the present invention, the component B further contains a binder, and preferably the content of the binder in the component B is 30-50 wt %. By adopting the above preferred solution, the catalytic performance of the composition can be further improved.

[0024] According to a preferred embodiment of the present invention, the binder is selected from at least one of alumina and pseudo-boehmite.

[0025] According to a preferred embodiment of the present invention, the SiO2 / Al2O3 molar ratio of the molecular sieve in the component B is 40-120. By adopting the above preferred embodiment, the catalytic performance of the composition can be further improved.

[0026] According to a preferred embodiment of the present invention, the content of hydrogenation active components in component A is 18-29 wt % in terms of oxide.

[0027] According to a preferred embodiment of the present invention, the hydrogenation active component comprises at least one of Group VIB metal elements and Group VIII metal elements.

[0028] According to a preferred embodiment of the present invention, the hydrogenation active component in component A comprises a Group VIB metal and a Group VIII metal, preferably, based on the total weight of component A, the content of the Group VIB metal in terms of oxide is 10-16 wt%, and the content of the Group VIII metal in terms of oxide is 8-13 wt%. By adopting the above preferred embodiment, the catalytic performance of the composition can be further improved.

[0029] According to a preferred embodiment of the present invention, the aluminum oxide in the component A contains γ aluminum oxide, preferably γ aluminum oxide.

[0030] According to a preferred embodiment of the present invention, the Group VIB metal is selected from molybdenum and / or chromium, preferably molybdenum.

[0031] According to a preferred embodiment of the present invention, the Group VIII metal is selected from at least one of nickel, palladium and platinum, preferably nickel.

[0032] According to a preferred embodiment of the present invention, the volume ratio of component A to component B in the composition is 1-3, preferably 1.5-2.5.

[0033] In the present invention, there are no special requirements for the preparation methods of component A and component B in the catalyst composition. According to the present invention, the preparation method of component A can be an impregnation method: an alumina carrier is impregnated in a solution containing a hydrogenation active component. There are no special requirements for the impregnation conditions. For example, the alumina can be placed in the impregnation solution at a solid-liquid volume ratio of 1:3 for 2 hours, then taken out and dried at 60°C for one night, and then roasted at 450°C for 6 hours. This step is repeated once to obtain component A. The preparation method of component B can be an impregnation method: a molecular sieve is mixed with a binder, and after adding an inorganic acid, it is kneaded and extruded into strips, dried and roasted, wherein the conditions for drying and roasting are not required, and the carrier obtained by impregnation and roasting with a solution containing a modifying element is then dried and roasted to obtain component B, wherein the conditions for drying and roasting are not required, for example, it can be dried at 110°C for 10 hours and roasted at 500°C for 6 hours.

[0034] The present invention provides a method for processing a raw material containing carbon four, which comprises: in a hydrogen-containing atmosphere, the raw material containing carbon four is contacted with a catalyst to obtain a diene cracking material; the catalyst comprises the composition of the present invention.

[0035] The catalyst composition of the present invention is used for treating raw materials containing C4 (such as liquefied petroleum gas), so that the raw materials can be efficiently converted into ethane and propane to obtain high-quality diene cracking materials.

[0036] In the present invention, component A and component B in the composition can be mixed for use, or can be filled in layers for use.

[0037] According to a preferred embodiment of the present invention, the content of C4 component in the C4-containing raw material is not less than 60wt%.

[0038] According to a preferred embodiment of the present invention, the C4-containing raw material is selected from liquefied petroleum gas and / or etherified C4.

[0039] According to a preferred embodiment of the present invention, the contact conditions include: the volume space velocity of the C4-containing raw material is 1-10h -1 .

[0040] According to a preferred embodiment of the present invention, the contact conditions include: the volume ratio of hydrogen to the C4-containing raw material is 50-300:1.

[0041] According to a preferred embodiment of the present invention, the contacting conditions include: the reaction temperature is 300-400°C.

[0042] According to a preferred embodiment of the present invention, the contact conditions include: the reaction pressure is 2-6 MPa.

[0043] The present invention will be described in detail below through examples. In the following examples, the element composition of the catalyst is determined by ICP; unless otherwise specified, the raw materials are all commercially available.

[0044] Example 1

[0045] Preparation method of catalyst:

[0046] Take 40 grams of the formed strip-shaped γ-alumina, and prepare 12.2wt% ammonium molybdate and 9.4wt% nickel nitrate solution respectively. Place the strip-shaped γ-alumina in the impregnation solution for 2 hours at a solid-liquid volume ratio of 1:3, then take it out and dry it at 60 degrees for one night, and then roast it at 450 degrees for 6 hours. Repeat this step once to obtain component A1. The elemental composition is detected by ICP. Based on the mass of component A1, the content of molybdenum oxide is 11.2%, and the content of nickel oxide is 8.6%.

[0047] Take 100.0 grams of ZSM-5 molecular sieve powder with a SiO2 / Al2O3 molar ratio of 45, mix it with 30 grams of alumina, add dilute nitric acid, knead and extrude into strips, dry and calcine. Prepare 14 grams of 2.8wt% zinc nitrate solution, add this solution to 20 grams of the formed carrier, then dry it at 110°C for 10 hours and calcine it at 500°C for 6 hours to obtain component B1. The elemental composition is detected by ICP, and the content of zinc oxide is 1.2% based on the mass of component B1.

[0048] Example 2

[0049] Preparation method of catalyst:

[0050] Take 50 grams of the formed strip-shaped γ-alumina, and prepare 8.4wt% ammonium molybdate and 7.7wt% nickel nitrate solution respectively. Place the strip-shaped γ-alumina in the impregnation solution for 2 hours at a solid-liquid volume ratio of 1:3, then take it out and dry it at 60 degrees for one night, and then roast it at 450 degrees for 6 hours. Repeat this step twice to obtain component A2. The elemental composition is detected by ICP. Based on the mass of component A2, the content of molybdenum oxide is 15.2%, and the content of nickel oxide is 12.6%.

[0051] Take 80.0 grams of ZSM-5 molecular sieve powder with a SiO2 / Al2O3 molar ratio of 110, mix it with 35 grams of alumina, add dilute nitric acid, knead and extrude into strips, dry and calcine. Prepare 20 grams of 5.6wt% gallium nitric acid solution, add this solution to 30 grams of the formed carrier, then dry it at 110℃ for 10 hours and calcine it at 500℃ for 6 hours to obtain component B2. The elemental composition is detected by ICP, and the gallium oxide content is 2.8% based on the mass of component B2.

[0052] Example 3

[0053] Preparation method of catalyst:

[0054] The preparation method of the catalyst of Part A is the same as that of Example 1;

[0055] Take 100.0 grams of ZSM-5 molecular sieve powder with a SiO2 / Al2O3 molar ratio of 80, mix it with 30 grams of aluminum oxide, add dilute nitric acid, knead and extrude into strips, dry and calcine. Prepare 20 grams of 1.8wt% zinc nitrate solution, 1.0wt% gallium nitrate and 1.1wt% diammonium hydrogen phosphate, add this solution to 34 grams of the formed carrier, then dry at 110°C for 10 hours and calcine at 500°C for 6 hours to obtain component B3. The elemental composition is detected by ICP. Based on the mass of component B3, the content of zinc oxide is 1.2%, the content of gallium oxide is 0.8%, and the content of phosphorus is 0.7%.

[0056] Example 4

[0057] Preparation method of catalyst:

[0058] The preparation method of the catalyst of Part A is the same as that of Example 1;

[0059] Take 100.0 grams of ZSM-5 molecular sieve powder with a SiO2 / Al2O3 molar ratio of 100, mix it with 30 grams of aluminum oxide, add dilute nitric acid, knead and extrude into strips, dry and calcine. Prepare 16 grams of 2.0wt% zinc nitrate solution and 1.0wt% gallium nitrate, add this solution to 23 grams of the formed carrier, then dry at 110°C for 10 hours and calcine at 500°C for 6 hours to obtain component B4. The elemental composition is detected by ICP. Based on the mass of component B4, the content of zinc oxide is 1.7%, and the content of gallium oxide is 0.8%.

[0060] Example 5

[0061] Preparation method of catalyst:

[0062] The preparation method of the catalyst of Part A is the same as that of Example 1;

[0063] Take 100.0 grams of mercerized molecular sieve powder with a SiO2 / Al2O3 molar ratio of 18, mix it with 30 grams of aluminum oxide, add dilute nitric acid, knead and extrude into strips, dry and calcine. Prepare 16 grams of 2.0wt% zinc nitrate solution and 1.0wt% gallium nitrate, add this solution to 23 grams of the formed carrier, then dry at 110°C for 10 hours and calcine at 500°C for 6 hours to obtain component B5. The elemental composition is detected by ICP. Based on the mass of component B5, the content of zinc oxide is 1.8%, and the content of gallium oxide is 0.7%.

[0064] Example 6

[0065] Liquefied petroleum gas (composition see Table 1) was introduced into a reactor (staged loading, loading volume ratio see Table 2) filled with component A and component B (catalysts prepared in Examples 1-5) in sequence, at a reaction pressure of 3 MPa, a reaction temperature of 360°C, and a volume space velocity of 4 h -1 Under the conditions, the volume ratio of hydrogen to liquefied petroleum gas is 200:1. The reaction results after the reaction are shown in Table 2.

[0066] The catalyst ratios are listed in Table 2

[0067] Comparative Example 1

[0068] Liquefied petroleum gas (composition see Table 1) was introduced into the reactor filled with component A only. The reaction pressure was 3 MPa, the reaction temperature was 360°C, and the volume space velocity of liquefied petroleum gas was 4 h -1 Under the conditions, the volume ratio of hydrogen to liquefied petroleum gas is 200:1. The reaction results after the reaction are shown in Table 2.

[0069] Comparative Example 2

[0070] Liquefied petroleum gas (composition see Table 1) was introduced into the reactor filled with component B only. The reaction pressure was 3 MPa, the reaction temperature was 360°C, and the volume space velocity of liquefied petroleum gas was 4 h -1 Under the conditions, the volume ratio of hydrogen to liquefied petroleum gas is 200:1. The reaction results after the reaction are shown in Table 2.

[0071] Table 1 Composition of liquefied petroleum gas

[0072]

[0073]

[0074] Table 2

[0075]

[0076] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A catalyst composition, characterized in that The composition comprises: Component A: alumina loaded with hydrogenation active components; Component B: ZSM-5 molecular sieve loaded with a modifying element, wherein the modifying element is selected from at least one of Group IIB elements, Group IIIA elements and Group VA elements.

2. The composition according to claim 1, wherein The content of the modifying element in the component B is 0.5-3wt%; and / or The modifying element comprises at least two of the Group VA elements, the Group IIB elements and the Group IIIA elements: When containing Group VA elements, the ratio of the total molar amount of Group IIB elements and / or Group IIIA elements to the molar amount of Group VA elements is 1.5-3.0; When no Group VA element is present, the molar ratio of the Group IIB element to the Group IIIA element is 0.1-5.

0.

3. The composition according to claim 1 or 2, wherein The Group IIB element is selected from Zn and / or Cd, preferably Zn; and / or The Group IIIA element is selected from Ga and / or In, preferably Ga; and / or The Group VA element is at least one selected from P, As, and Sb, preferably P.

4. The composition according to any one of claims 1 to 3, wherein The component B further contains a binder, and preferably the content of the binder in the component B is 30-50wt%; more preferably, The binder is selected from at least one of alumina and pseudo-boehmite; and / or The SiO2 / Al2O3 molar ratio of the molecular sieve in the component B is 40-120.

5. The composition according to any one of claims 1 to 4, wherein The content of the hydrogenation active component in the component A is 18-29 wt % in terms of oxide. Preferably, the hydrogenation active component comprises at least one of the metal elements of Group VIB and Group VIII. More preferably, The hydrogenation active component in the component A comprises a Group VIB metal and a Group VIII metal. Preferably, based on the total weight of the component A, the content of the Group VIB metal in terms of oxide is 10-16 wt%, and the content of the Group VIII metal in terms of oxide is 8-13 wt%.

6. The composition according to any one of claims 1 to 5, wherein The Group VIB metal is selected from molybdenum and / or chromium, preferably molybdenum; and / or The Group VIII metal is selected from at least one of nickel, palladium and platinum, preferably nickel; and / or The alumina in the component A contains γ alumina.

7. A composition according to any one of claims 1 to 6, wherein The volume ratio of component A to component B in the composition is 1-3, preferably 1.5-2.

5.

8. A method for processing a raw material containing carbon four, characterized in that: The method comprises: in a hydrogen-containing atmosphere, a C4-containing raw material is contacted with a catalyst to obtain a diene cracking material; The catalyst comprises the composition according to any one of claims 1 to 7.

9. The processing method according to claim 8, wherein: The content of C4 component in the C4-containing raw material is not less than 60wt%; Preferably, the C4-containing raw material is selected from liquefied petroleum gas and / or etherified C4.

10. The processing method according to claim 8 or 9, wherein: The contact conditions include: The volume space velocity of the raw material containing C4 is 1-10h -1 ; and / or The volume ratio of hydrogen to C4-containing raw material is 50-300:1; and / or The reaction temperature is 300-400°C; and / or The reaction pressure is 2-6MPa.

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