Catalyst compositions, their use and processes for the dehydrogenation of lower alkanes

Abstract

This invention relates to the field of catalysts, specifically to a catalyst composition and its application, and a method for dehydrogenating low-carbon alkanes. The catalyst composition comprises a supported catalyst, a first promoter component, and a second promoter component. The first promoter component comprises a first silicon and / or aluminum compound containing a modifying element, and the second promoter component comprises a second silicon and / or aluminum compound. The modifying element comprises at least one element selected from Group IA, Group IIA, Group IB, Group IIB, Group VB, and Group VIII. By introducing the first and second promoter components, this invention significantly improves the heat transfer efficiency of the reaction. In the dehydrogenation reaction stage, it reduces the heat absorbed by the catalyst bed for the dehydrogenation of low-carbon alkanes such as propane, reduces the temperature drop, and improves the catalytic efficiency.

Description

Technical Field

[0001] This invention relates to the field of catalysts, and more specifically to a catalyst composition, its application, and a method for dehydrogenation of low-carbon alkanes. Background Technology

[0002] Propylene is an important chemical raw material. Currently, the main processes for large-scale production of propylene are the petroleum route, the coal route, and the propane route. Among them, the propane route has developed rapidly in China in recent years due to its advantages such as low investment cost and low carbon emissions.

[0003] Chromium-based catalysts have advantages over other types of catalysts, such as low cost and high catalytic activity. How to better utilize the role of chromium-based catalysts is one of the research hotspots.

[0004] CN110841709B discloses a method for preparing a chromium-based catalyst for propane dehydrogenation to propylene. By constructing a composite support of titanium silicate molecular sieve TS-1 and alumina, the acidity and acid strength of the support surface are adjusted through the combination of the two. This promotes the loading and dispersion of the active component chromium on the support surface, thereby improving the catalytic effect.

[0005] CN108654596B discloses a propane dehydrogenation catalyst and its preparation method. By synthesizing chromium composite oxide, the dispersion of chromium on the support is improved, and the activity and selectivity of the catalyst are effectively improved by metal modification treatment.

[0006] CN110152650B discloses a propane dehydrogenation to propylene supported catalyst and its preparation method. By using a support material that is resistant to high-temperature sintering and phase transformation and has a high specific surface area at high temperatures, the problem of catalyst deactivation caused by the easy occurrence of sintering or crystal phase transformation of the support during the reaction and carbonization activation process is solved.

[0007] Current research focuses primarily on catalyst improvement; however, due to material limitations, catalysts have limited capacity to improve heat transfer. For high-temperature dehydrogenation reactions, enhancing heat transfer within the reactor is crucial for improving propane dehydrogenation efficiency. Summary of the Invention

[0008] The purpose of this invention is to overcome the heat transfer problem of propane dehydrogenation catalysts in the prior art, and to provide a catalyst composition, its application, and a method for dehydrogenation of low-carbon alkanes. This catalyst composition has a large heat storage capacity and heat transfer efficiency, as well as high catalytic activity.

[0009] To achieve the above objectives, a first aspect of the present invention provides a catalytic composition comprising a supported catalyst, a first promoter component, and a second promoter component. The first promoter component comprises a first silicon and / or aluminum compound containing a modifying element, and the second promoter component comprises a second silicon and / or aluminum compound. The modifying element comprises at least one of a Group IA element, a Group IIA element, a Group IB element, a Group IIB element, a Group VA element, and a Group VIII element.

[0010] A second aspect of the present invention provides the application of the catalytic composition described in the first aspect of the present invention in a dehydrogenation reaction.

[0011] A third aspect of the present invention provides a method for dehydrogenating low-carbon alkanes, the method comprising reacting the low-carbon alkanes with the catalytic composition described in the first aspect of the present invention.

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

[0013] By introducing a first auxiliary component and a second auxiliary component, this invention greatly improves the heat transfer efficiency of the reaction. In the dehydrogenation reaction stage, it reduces the heat absorbed by the catalyst bed for the dehydrogenation of low-carbon alkanes such as propane, reduces the temperature drop, and improves the catalytic efficiency. Attached Figure Description

[0014] Figure 1 This is the H2-TPR curve of the first auxiliary agent component prepared in Example 1 of the present invention. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] The present invention provides a catalytic composition comprising a supported catalyst, a first promoter component, and a second promoter component. The first promoter component comprises a first silicon and / or aluminum compound containing a modifying element, and the second promoter component comprises a second silicon and / or aluminum compound. The modifying element contains at least one of a Group IB element, a Group IIB element, and a Group VB element, and optionally at least one of a Group IA element, a Group IIA element, and a Group VIII element.

[0017] The catalyst composition of the present invention contains a first auxiliary component and a second auxiliary component comprising a first silicon and / or aluminum compound containing modified elements, which greatly improves the heat transfer efficiency of the reaction. In the dehydrogenation reaction stage, it reduces the heat absorbed by the catalyst bed for the dehydrogenation of low-carbon alkanes such as propane, reduces the temperature drop, improves the catalytic efficiency, and can be reduced by reducing gases such as olefins and hydrogen, and releases heat during the reduction process.

[0018] According to a preferred embodiment of the present invention, the Group IA element is selected from lithium, sodium, and potassium, preferably sodium.

[0019] According to a preferred embodiment of the present invention, the Group IIA element is selected from magnesium and calcium, preferably calcium.

[0020] According to a preferred embodiment of the present invention, the Group IB element is selected from copper and silver, preferably copper.

[0021] According to a preferred embodiment of the present invention, the Group IIB element is selected from zinc.

[0022] According to a preferred embodiment of the present invention, the Group VB element is selected from vanadium and / or niobium.

[0023] According to a preferred embodiment of the present invention, the Group VIII element is selected from at least one of iron, cobalt, and nickel, preferably nickel.

[0024] In this invention, there are no special requirements for the mass content of the modified element in the first auxiliary agent component. According to a preferred embodiment of the invention, the mass ratio of the modified element to the carrier in the first auxiliary agent component is 20-50%, preferably 30-40%. By adopting the aforementioned preferred scheme, the rate and total amount of heat released during the reduction process can be controlled more rationally, the dehydrogenation efficiency of the reaction can be optimized, and the heat transfer efficiency of the reaction can be improved.

[0025] In this invention, the modifying element can be selected from any element within the aforementioned scope. According to a preferred embodiment of this invention, the modifying element contains one or two of Group IB elements, Group IIA elements, and Group VIII elements. By adopting the aforementioned preferred scheme, it is possible to regulate the heat during the dehydrogenation reaction while preventing adverse side reactions, thus optimizing the dehydrogenation efficiency and improving the heat transfer efficiency of the reaction.

[0026] In this invention, the specific type of the first silicon and / or aluminum compound is not particularly limited. According to a preferred embodiment of the invention, the first silicon and / or aluminum compound is selected from at least one of alumina, silicon oxide, calcium silicate, calcium aluminate, and silicon carbide, preferably calcium aluminate. By adopting the aforementioned preferred scheme, the dispersion of the loaded modifying elements can be stabilized, allowing it to withstand a sufficient number of reduction processes, thus optimizing the dehydrogenation efficiency of the reaction and improving the heat transfer efficiency of the reaction.

[0027] In this invention, the specific type of the second silicon and / or aluminum compound is not particularly limited. According to a preferred embodiment of the invention, the second silicon and / or aluminum compound is selected from at least one of alumina, silicon oxide, calcium silicate, calcium aluminate, and silicon carbide, preferably alumina. By adopting the aforementioned preferred embodiment, uniform heat transfer during the reaction can be controlled, local hot spots can be prevented, the dehydrogenation efficiency of the reaction can be optimized, and the heat transfer efficiency of the reaction can be improved.

[0028] In this invention, there is no particular limitation on the volume ratio of the supported catalyst, the first promoter component, and the second promoter component in the catalytic composition. According to a preferred embodiment of the invention, the volume ratio of the supported catalyst, the second promoter component, and the first promoter component in the catalytic composition is 1:0.3-1.2:0.05-0.75, preferably 1:0.5-1:0.1-0.5. By adopting the aforementioned preferred embodiment, the heat distribution of the catalyst composition during the reaction process can be optimized, enabling it to maintain high heat transfer efficiency and dehydrogenation efficiency throughout its entire lifespan.

[0029] In this invention, the supported catalyst can be a conventional choice in the art. According to a preferred embodiment of the invention, the supported catalyst is a dehydrogenation catalyst, preferably a low-carbon alkane dehydrogenation catalyst.

[0030] According to a preferred embodiment of the present invention, the supported catalyst includes a support and an active component supported on the support, wherein the active component contains at least one element selected from Group IA, Group IIA, Group IIIA, Group IVB, Group VIB, and Group VIII.

[0031] According to a preferred embodiment of the present invention, the active component in the supported catalyst is at least one element from Group IVB.

[0032] In this invention, there are no special requirements for the loading amount of the active component in the supported catalyst. According to a preferred embodiment of the present invention, the loading amount of the active component in the supported catalyst is 0.1-30%, preferably 0.5-25%.

[0033] In this invention, the support in the supported catalyst can be a conventional choice in the art. According to a preferred embodiment of the invention, the support in the supported catalyst is selected from at least one of molecular sieves, alumina, silica and activated carbon.

[0034] According to a preferred embodiment of the present invention, in the supported catalyst, the Group IA element is selected from sodium and / or potassium, preferably sodium.

[0035] According to a preferred embodiment of the present invention, in the supported catalyst, the Group IIA element is selected from magnesium and / or calcium, preferably calcium.

[0036] According to a preferred embodiment of the present invention, in the supported catalyst, the Group IIIA element is selected from boron and / or gallium, preferably gallium.

[0037] According to a preferred embodiment of the present invention, in the supported catalyst, the Group IVB element is selected from titanium and / or zirconium, preferably zirconium.

[0038] According to a preferred embodiment of the present invention, in the supported catalyst, the Group VIB element is selected from chromium and / or molybdenum, preferably chromium.

[0039] According to a preferred embodiment of the present invention, in the supported catalyst, the Group VIII element is selected from at least one of iron, cobalt, and nickel, preferably cobalt.

[0040] According to a preferred embodiment of the present invention, the specific surface area of ​​the first auxiliary agent component is 1-50 m². 2 / g, preferably 5-45m 2 / g.

[0041] According to a preferred embodiment of the present invention, the specific heat capacity of the first additive component is 700-910 J / (Kg*℃), preferably 750-860 J / (Kg*℃).

[0042] According to a preferred embodiment of the present invention, the reduction peak value of the first auxiliary component is 200-300℃.

[0043] In this invention, the preparation method of the first auxiliary component can be a conventional choice in the art, as long as it can prepare the first auxiliary component with the aforementioned properties of this invention. The preparation method of the first auxiliary component includes: using a first silicon and / or aluminum compound as a carrier, contacting it with a modified element solution, controlling the pH value to 6-9, obtaining a precursor of the first auxiliary component, drying and calcining to obtain the first auxiliary component.

[0044] According to a preferred embodiment of the present invention, the first auxiliary component precursor is dried at 60-150°C for 0.5-8 hours and calcined at 1000-1400°C for 4-48 hours.

[0045] According to a preferred embodiment of the present invention, the pH value is controlled to be 6-9 by adding an alkaline substance such as ammonia to the system to obtain a first auxiliary component precursor.

[0046] This invention provides an application of the catalytic composition described herein in a dehydrogenation reaction, preferably in the dehydrogenation of low-carbon alkanes.

[0047] The catalyst composition of the present invention has the advantages of high catalytic activity and long life when used for dehydrogenation, especially for dehydrogenation of low-carbon alkanes.

[0048] The present invention provides a method for dehydrogenating low-carbon alkanes, the method comprising reacting the low-carbon alkanes with the catalytic composition described in the present invention.

[0049] According to a preferred embodiment of the present invention, the conditions for the contact reaction include: a temperature of 500-650°C, a pressure of 0.05-0.15 MPa, and a mass hourly space velocity of 0.5-5 h⁻¹. -1 .

[0050] According to a preferred embodiment of the present invention, the low-carbon alkane is selected from alkanes with 6 or fewer carbon atoms, preferably propane.

[0051] The present invention will be described in detail below through examples. In the following examples, the specific surface area was measured using a Micron TriStar 3000; the specific heat capacity was measured using a Setaram MHTC 96; and the reduction peak value was measured using a fully automated chemisorption analyzer manufactured by Micron Corporation. All raw materials were commercially available products.

[0052]

[0053]

[0054] Example 1

[0055] Preparation of the first auxiliary component:

[0056] Copper nitrate, calcium nitrate, and silicon dioxide were selected. Copper nitrate and calcium nitrate were weighed according to a copper:calcium:silicon dioxide mass ratio of 10:20:100. After dissolving in water, ammonia was added to adjust the pH to 6. The mixture was then mixed with silicon dioxide and dried at 60℃ for 8 hours, followed by calcination at 1400℃ for 4 hours to obtain the first auxiliary agent component. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1, and the H2-TPR curve is shown in [Table 1]. Figure 1 .

[0057] The catalyst (prepared according to Example 1 of CN110560041B), silica, and the first auxiliary agent component were mixed at a volume ratio of 1:0.5:0.5, and then subjected to a temperature of 600°C, a pressure of 0.1 MPa, and a mass hourly space velocity of 1 h⁻¹. -1 Under the given conditions, it was reacted with propane in an adiabatic manner for 10 minutes to obtain data on temperature drop, conversion rate, and selectivity.

[0058] See Table 2 for specific parameters.

[0059] Example 2

[0060] The preparation method of the first auxiliary agent component was carried out according to Example 1, except that ammonia was added to adjust the pH to 9, and the mixture was dried at 150°C for 0.5 h and then calcined at 1000°C for 48 h. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1.

[0061] The catalyst (prepared according to Example 1 of CN110560041B), silicon dioxide, and the first auxiliary agent component were mixed at a volume ratio of 1:1.2:0.75, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0062] Example 3

[0063] The preparation method of the first auxiliary agent component was carried out according to Example 1, except that ammonia was added to adjust the pH to 7.5, and the mixture was dried at 100°C for 4 hours and then calcined at 1200°C for 24 hours. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1.

[0064] The catalyst (prepared according to Example 1 of CN110560041B), silicon oxide, and the first auxiliary agent component were mixed at a volume ratio of 1:1:0.1, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0065] Example 4

[0066] The preparation method of the first auxiliary component is the same as in Example 1, except that the mass ratio of copper, calcium and silicon oxide is 5:5:100. The specific surface area and specific heat capacity of the first auxiliary component are shown in Table 1.

[0067] The catalyst (prepared according to Example 1 of CN110560041B) and its composition were mixed in the proportion of Example 1, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0068] Example 5

[0069] The preparation method of the first auxiliary component is the same as in Example 1, except that the mass ratio of sodium, zinc and silicon oxide is 10:20:100. The specific surface area and specific heat capacity of the first auxiliary component are shown in Table 1.

[0070] The catalyst (prepared according to Example 1 of CN110560041B) and its composition were mixed in the proportion of Example 1. The difference was that the second auxiliary component was silicon carbide. The reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0071] Example 6

[0072] The preparation method of the first auxiliary component is carried out according to Example 1, except that the first silicon and / or aluminum compound is calcium aluminate. The specific surface area and specific heat capacity of the first auxiliary component are shown in Table 1.

[0073] The catalyst (prepared according to Example 1 of CN110560041B) and its composition were mixed in the proportion of Example 1. The difference was that the second auxiliary component was alumina. The reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0074] Example 7

[0075] The preparation method of the first auxiliary component is carried out in accordance with Example 1. The specific surface area and specific heat capacity of the first auxiliary component are shown in Table 1.

[0076] The catalyst (prepared according to Example 1 of CN110560041B), alumina, and the first auxiliary agent component were mixed at a volume ratio of 1:1.5:1. The reaction conditions were the same as in Example 1, and the specific parameters are shown in Table 2.

[0077] Example 8

[0078] The preparation method of the first auxiliary component is carried out in accordance with Example 1. The specific surface area and specific heat capacity of the first auxiliary component are shown in Table 1.

[0079] The catalyst (prepared according to Example 1 of CN110560041B), alumina, and the first auxiliary agent component were mixed at a volume ratio of 1:0.1:0.01. The reaction conditions were the same as in Example 1, and the specific parameters are shown in Table 2.

[0080] Example 9

[0081] The preparation method of the first auxiliary agent component was carried out according to Example 1, except that ammonia water was not added during the preparation process, and the calcination temperature was 2000℃ for 48 hours. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1.

[0082] The catalyst (prepared according to Example 1 of CN110560041B), alumina, and the first auxiliary agent component were mixed at a volume ratio of 1:0.5:0.5, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0083] Comparative Example 1

[0084] The catalyst (prepared according to Example 1 of CN110560041B) was subjected to a temperature of 600°C, a pressure of 0.1 MPa, and a mass hourly space velocity of 1 h⁻¹. -1 Under the specified conditions, the mixture was reacted with propane in an adiabatic manner for 10 minutes, and the data on temperature drop, conversion rate, and selectivity were obtained. See Table 1.

[0085] Comparative Example 2

[0086] The catalyst (prepared according to Example 1 of CN110560041B) and silicon oxide were mixed at a volume ratio of 1:0.5, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0087] Comparative Example 3

[0088] The preparation method of the first auxiliary agent component is as described in Example 1. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1.

[0089] The catalyst (prepared according to Example 1 of CN110560041B) and the first auxiliary agent component were mixed at a volume ratio of 1:0.5, and the reaction conditions were the same as in Example 1. The specific parameters are shown in Table 2.

[0090] Comparative Example 4

[0091] The preparation method of the first auxiliary agent component is as described in Example 1. The specific surface area and specific heat capacity of the first auxiliary agent component are shown in Table 1.

[0092] After mixing silicon oxide and the first auxiliary agent component at a volume ratio of 0.5:0.5, the reaction conditions were the same as in Example 1, and the specific parameters are shown in Table 2.

[0093] Table 1

[0094]

[0095]

[0096] Table 2

[0097]

[0098]

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalytic composition, characterized in that, The catalytic composition comprises a supported catalyst, a first auxiliary component, and a second auxiliary component. The first auxiliary component comprises a first silicon and / or aluminum compound containing a modifying element, and the second auxiliary component comprises a second silicon and / or aluminum compound. The volume ratio of the supported catalyst, the second auxiliary component, and the first auxiliary component in the catalytic composition is 1:0.3-1.2:0.05-0.75; The modifying element contains at least one of Group IB, Group IIB, and Group VB elements, and at least one of Group IA, Group IIA, and Group VIII elements.

2. The catalytic composition according to claim 1, wherein, The mass ratio of the modifying element to the carrier in the first auxiliary agent component is 20-50%.

3. The catalytic composition according to claim 2, wherein, The mass ratio of the modifying element to the carrier in the first auxiliary agent component is 30-40%. The modified element contains one or two of Group IB elements, Group IIA elements, and Group VIII elements.

4. The catalytic composition according to claim 1, wherein, The first silicon and / or aluminum compound is selected from at least one of alumina, silicon oxide, calcium silicate, calcium aluminate, and silicon carbide; and / or The second silicon and / or aluminum compound is selected from at least one of alumina, silicon oxide, calcium silicate, calcium aluminate, and silicon carbide.

5. The catalytic composition according to claim 4, wherein, The first silicon and / or aluminum compound is calcium aluminate; and / or The second silicon and / or aluminum compound is aluminum oxide.

6. The catalytic composition according to claim 1, wherein, The volume ratio of the supported catalyst, the second auxiliary component, and the first auxiliary component in the catalytic composition is 1:0.5-1:0.1-0.

5.

7. The catalytic composition according to claim 1, wherein, The supported catalyst is a dehydrogenation catalyst; and / or The supported catalyst includes a support and an active component supported on the support, wherein the active component contains at least one element selected from Group IA, Group IIA, Group IIIA, Group IVB, Group VIB, and Group VIII.

8. The catalytic composition according to claim 7, wherein, The supported catalyst is a low-carbon alkane dehydrogenation catalyst.

9. The catalytic composition according to claim 7, wherein, The active component in the supported catalyst is at least one element from Group IVB.

10. The catalytic composition according to claim 9, wherein, The loading of the active component in the supported catalyst is 0.1-30%.

11. The catalytic composition according to claim 10, wherein, The loading of the active component in the supported catalyst is 0.5-25%.

12. The catalytic composition according to claim 7, wherein, The supported catalyst is selected from at least one of molecular sieves, alumina, silica, and activated carbon; and / or In the supported catalyst Group IA elements are selected from sodium and / or potassium; and / or Group IIA elements are selected from magnesium and / or calcium; and / or Group IIIA elements are selected from boron and / or gallium; and / or Group IVB elements are selected from titanium and / or zirconium; and / or Group VIB elements are selected from chromium and / or molybdenum; and / or Group VIII elements are selected from at least one of iron, cobalt, and nickel.

13. The catalytic composition according to claim 12, wherein, The element in Group IA is sodium; and / or Group IIA element calcium; and / or Group IIIA elements are gallium; and / or Zirconium, a Group IVB element; and / or Group VIB element is chromium; and / or Group VIII element is cobalt.

14. The catalytic composition according to claim 1, wherein, The specific surface area of ​​the first auxiliary component is 1-50 m². 2 / g; and / or The specific heat capacity of the first auxiliary component is 700-910 J / (kg). ℃); and / or The reduction peak value of the first auxiliary component is 200-300℃.

15. The catalytic composition according to claim 14, wherein, The specific surface area of ​​the first auxiliary component is 5-45 m². 2 / g; and / or The specific heat capacity of the first auxiliary component is 750-860 J / (kg). ℃).

16. The catalytic composition according to any one of claims 1-15, wherein, The preparation method of the first auxiliary component includes: using a first silicon and / or aluminum compound as a carrier, contacting it with a modified element solution, controlling the pH value to 6-9, obtaining a precursor of the first auxiliary component, and drying and calcining to obtain the first auxiliary component.

17. The catalytic composition according to claim 16, wherein, The first auxiliary component precursor is dried at 60-150℃ for 0.5-8h and calcined at 1000-1400℃ for 4-48h.

18. The use of the catalytic composition according to any one of claims 1-17 in a dehydrogenation reaction.

19. The application according to claim 18, wherein the application is in the dehydrogenation of low-carbon alkanes.

20. A method for dehydrogenating low-carbon alkanes, characterized in that, The method includes reacting a low-carbon alkane with a catalytic composition according to any one of claims 1-17.

21. The method according to claim 20, wherein, The conditions for the contact reaction include: a temperature of 500-650℃, a pressure of 0.05-0.15 MPa, and a mass hourly space velocity of 0.5-5 h⁻¹. -1 ; and / or The low-carbon alkanes are selected from alkanes with 6 or fewer carbon atoms.

22. The method according to claim 21, wherein, The low-carbon alkane is propane.

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