Catalyst composition, application thereof and light alkane dehydrogenation method

Abstract

The invention relates to the field of catalysts, in particular to a catalyst composition, application thereof and a low-carbon alkane dehydrogenation method. The catalytic composition comprises a supported catalyst, a first auxiliary agent component and a second auxiliary agent component, the first auxiliary agent component comprises a first silicon and / or aluminum compound containing a modifying element, and the second auxiliary agent component comprises a second silicon and / or aluminum compound; the modified element comprises at least one of an IA group element, a IIA group element, an IB group element, a IIB group element, a VB group element and a VIII group element. By introducing the first aid component and the second aid component, the heat transfer efficiency of the reaction is greatly improved, and in the dehydrogenation reaction stage, the heat absorption capacity of a catalyst bed layer for dehydrogenation of low-carbon alkane such as propane is reduced, the temperature drop is reduced, and the catalytic efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of catalysts, and in particular to a catalyst composition and application thereof and a method for dehydrogenating low-carbon alkanes. Background Art

[0002] Propylene is an important chemical raw material. Currently, the main process routes for large-scale production of propylene are oil route, coal route and 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] Compared with other types of catalysts, chromium-based catalysts have the advantages of low price and high catalytic activity. How to better play the role of chromium-based catalysts is one of the research hotspots.

[0004] CN110841709B discloses a method for preparing a chromium catalyst for the dehydrogenation of propane to propylene. By constructing a composite carrier of titanium silicon molecular sieve TS-1 and aluminum oxide, the surface acid amount and acid strength of the carrier are adjusted by the composite of the two. The load dispersion of the active component chromium on the carrier surface is promoted, thereby improving the catalytic effect.

[0005] CN108654596B discloses a propane dehydrogenation catalyst and a preparation method thereof. The dispersion of chromium on a carrier is improved by synthesizing a chromium composite oxide, 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 a preparation method thereof. By adopting a carrier material that is resistant to high-temperature sintering and phase change and has a high specific surface area at high temperatures, the problem of the catalyst being easily sintered or undergoing a crystal phase transition during the reaction and carbonization activation treatment, which leads to catalyst deactivation, is solved.

[0007] It can be seen that current research is mostly focused on improving catalysts, but due to the limitations of the catalyst itself, the ability to improve heat transfer is limited. For dehydrogenation reactions at high temperatures, improving heat transfer in the reactor is the key issue to improving the efficiency of propane dehydrogenation. Summary of the invention

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

[0009] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a catalytic composition, which 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 modifying element comprises at least one of Group IA elements, Group IIA elements, Group IB elements, Group IIB elements, Group VB elements and Group VIII elements.

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

[0011] The third aspect of the present invention provides a method for dehydrogenating light alkanes, which comprises contacting and reacting light 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] The present invention greatly improves the heat transfer efficiency of the reaction by introducing the first auxiliary component and the second auxiliary component. In the dehydrogenation reaction stage, the heat absorption of the catalyst bed for the dehydrogenation of low-carbon alkanes such as propane is reduced, the temperature drop is reduced, and the catalytic efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the H2-TPR curve of the first auxiliary agent component prepared in Example 1 of the present invention. 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 catalytic composition, which comprises a supported catalyst, a first auxiliary component and a second auxiliary component, wherein 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 modifying element comprises at least one of Group IB elements, Group IIB elements, and Group VB elements, and optionally at least one of Group IA elements, Group IIA elements, and Group VIII elements.

[0017] The catalyst composition of the present invention contains a first auxiliary agent component including a first silicon and / or aluminum compound containing a modifying element and a second auxiliary agent component, which greatly improves the heat transfer efficiency of the reaction. In the dehydrogenation reaction stage, the heat absorption of the catalyst bed for the dehydrogenation of low-carbon alkanes such as propane is reduced, the temperature drop is reduced, the catalytic efficiency is improved, and the catalyst composition can be reduced by reducing gases such as olefins, hydrogen, etc., and the heat is released during the reduction process.

[0018] According to a preferred embodiment of the present invention, the Group IA element is selected from lithium, sodium, 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 the present invention, there is no particular requirement for the mass content of the modifying element in the first auxiliary component. According to a preferred embodiment of the present invention, the mass ratio of the modifying element in the first auxiliary component to the mass of the carrier is 20-50%, preferably 30-40%. By adopting the above preferred scheme, the rate and total value of heat released during the reduction process can be more reasonably controlled, the reaction dehydrogenation efficiency is optimized, and the heat transfer efficiency of the reaction is improved.

[0025] In the present invention, the modifying element can be selected from the aforementioned range of the present invention. According to a preferred embodiment of the present invention, the modifying element contains one or two of the Group IIB elements, the Group IIA elements, and the Group VIII elements. By adopting the aforementioned preferred scheme, the heat in the dehydrogenation reaction process can be adjusted without causing side reactions that are unfavorable to the reaction, thereby optimizing the dehydrogenation efficiency of the reaction and improving the heat transfer efficiency of the reaction.

[0026] In the present invention, there is no particular restriction on the specific type of the first silicon and / or aluminum compound. According to a preferred embodiment of the present invention, the first silicon and / or aluminum compound is selected from at least one of aluminum oxide, silicon oxide, calcium silicate, calcium aluminate and silicon carbide, preferably calcium aluminate. By adopting the aforementioned preferred scheme, the dispersion of the loaded modifying element can be stabilized so that it can withstand a sufficient number of reduction processes, optimize the reaction dehydrogenation efficiency, and improve the heat transfer efficiency of the reaction.

[0027] In the present invention, there is no particular restriction on the specific type of the second silicon and / or aluminum compound. According to a preferred embodiment of the present invention, the second silicon and / or aluminum compound is selected from at least one of aluminum oxide, silicon oxide, calcium silicate, calcium aluminate and silicon carbide, preferably aluminum oxide. By adopting the above preferred scheme, it is possible to control uniform heat transfer during the reaction, prevent the generation of local hot spots, optimize the reaction dehydrogenation efficiency, and improve the heat transfer efficiency of the reaction.

[0028] In the present invention, there is no particular restriction on the volume ratio of the supported catalyst, the first auxiliary component and the second auxiliary component in the catalytic composition. According to a preferred embodiment of the present invention, 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, preferably 1:0.5-1:0.1-0.5. By adopting the above preferred embodiment, the heat distribution of the catalyst composition during the reaction can be optimized, so that it can maintain a high heat transfer efficiency and dehydrogenation efficiency throughout the life cycle.

[0029] In the present invention, the supported catalyst may be a conventional choice in the art. According to a preferred embodiment of the present invention, the supported catalyst is a dehydrogenation catalyst, preferably a light alkane dehydrogenation catalyst.

[0030] According to a preferred embodiment of the present invention, the supported catalyst comprises a carrier and an active component supported on the carrier, and the active component contains at least one of Group IA elements, Group IIA elements, Group IIIA elements, Group IVB elements, Group VIB elements and Group VIII elements.

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

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

[0033] In the present invention, the carrier in the supported catalyst can be a conventional choice in the art. According to a preferred embodiment of the present invention, the carrier in the supported catalyst is selected from at least one of molecular sieves, alumina, silicon oxide 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 component is 1-50m 2 / g, preferably 5-45m 2 / g.

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

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

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

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

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

[0046] The present invention provides an application of the catalytic composition of the present invention in a dehydrogenation reaction, preferably in the dehydrogenation of light alkanes.

[0047] The catalyst composition of the present invention is used for dehydrogenation, especially for dehydrogenation of light alkanes, and has the advantages of high catalytic activity and long service life.

[0048] The present invention provides a method for dehydrogenating light alkanes, which comprises contacting and reacting the light alkanes with the catalytic composition of the present invention.

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

[0050] According to a preferred embodiment of the present invention, the low carbon alkane is selected from alkanes below C6, preferably propane.

[0051] The present invention will be described in detail below through examples. In the following examples, the specific surface area is measured by Micromeritics TriStar 3000; the specific heat capacity is measured by Setaram MHTC 96, and the reduction peak value test is measured by a fully automatic chemisorption instrument produced by Micromeritics, USA. All raw materials are commercially available.

[0052]

[0053]

[0054] Example 1

[0055] Preparation of the first auxiliary component:

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

[0057] The catalyst (prepared according to Example 1 of CN110560041B), silicon oxide and the first auxiliary agent component were mixed in a volume ratio of 1:0.5:0.5 and heated at a temperature of 600°C, a pressure of 0.1 MPa and a mass space velocity of 1 h -1 Under the conditions, it was adiabatically contacted with propane for 10 minutes to obtain the temperature drop, conversion rate and selectivity data.

[0058] See Table 2 for specific parameters.

[0059] Example 2

[0060] The preparation method of the first auxiliary agent component is carried out according to Example 1, except that ammonia water is added to adjust the pH to 9, the mixture is dried at 150°C for 0.5h, and then calcined at 1000°C for 48h. 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 oxide, and the first auxiliary agent component were mixed in a volume ratio of 1:1.2:0.75, and the reaction conditions were the same as those in Example 1. The specific parameters are shown in Table 2.

[0062] Example 3

[0063] The preparation method of the first auxiliary agent component is carried out according to Example 1, except that ammonia water is added to adjust the pH to 7.5, the mixture is 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 in a volume ratio of 1:1:0.1, and the reaction conditions were the same as those in Example 1. The specific parameters are shown in Table 2.

[0065] Example 4

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

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

[0068] Example 5

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

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

[0071] Example 6

[0072] The preparation method of the first auxiliary agent 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 agent component are shown in Table 1.

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

[0074] Example 7

[0075] The preparation method of the first auxiliary agent component is carried out according to Example 1. The specific surface area and specific heat capacity of the first auxiliary agent 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 in a volume ratio of 1:1.5:1, and the reaction conditions were the same as those in Example 1. The specific parameters obtained are shown in Table 2.

[0077] Example 8

[0078] The preparation method of the first auxiliary agent component is carried out according to Example 1. The specific surface area and specific heat capacity of the first auxiliary agent 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 in a volume ratio of 1:0.1:0.01, and the reaction conditions were the same as those in Example 1. The specific parameters are shown in Table 2.

[0080] Example 9

[0081] The preparation method of the first auxiliary agent component is carried out according to Example 1, except that no ammonia water is added during the preparation process, and the calcination temperature is 2000° C. 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 in a volume ratio of 1:0.5:0.5, and the reaction conditions were the same as those 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 heated to 600°C, with a pressure of 0.1 MPa and a mass space velocity of 1 h -1 Under the above conditions, the reaction was carried out adiabatically with propane for 10 min, and the temperature drop, conversion rate and selectivity data were obtained. See Table 1.

[0085] Comparative Example 2

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

[0087] Comparative Example 3

[0088] The preparation method of the first auxiliary agent component is carried out according to 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 those in Example 1. The specific parameters obtained are shown in Table 2.

[0090] Comparative Example 4

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

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

[0093] Table 1

[0094]

[0095]

[0096] Table 2

[0097]

[0098]

[0099] 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 catalytic composition, characterized in that The catalytic composition comprises a supported catalyst, a first auxiliary component and a second auxiliary component, wherein 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 modifying element contains at least one of Group IB elements, Group IIB elements, and Group VB elements, and optionally at least one of Group IA elements, Group IIA elements, and Group VIII elements.

2. The catalytic composition according to claim 1, wherein The mass ratio of the modifying element in the first auxiliary component to the mass ratio of the carrier is 20-50%, preferably 30-40%; Preferably, the modifying element contains Group IB elements and one or two of Group IIA elements and Group VIII elements.

3. The catalytic composition according to claim 1 or 2, wherein: The first silicon and / or aluminum compound is selected from at least one of aluminum oxide, silicon oxide, calcium silicate, calcium aluminate and silicon carbide, preferably selected from calcium aluminate; and / or The second silicon and / or aluminum compound is selected from at least one of aluminum oxide, silicon oxide, calcium silicate, calcium aluminate and silicon carbide, and is preferably selected from aluminum oxide.

4. The catalytic composition according to any one of claims 1 to 3, wherein The volume ratio of the supported catalyst, the second auxiliary agent component and the first auxiliary agent component in the catalytic composition is 1:0.3-1.2:0.05-0.75, preferably 1:0.5-1:0.1-0.

5.

5. The catalytic composition according to any one of claims 1 to 4, wherein: The supported catalyst is a dehydrogenation catalyst, preferably a light alkane dehydrogenation catalyst; and / or The supported catalyst comprises a carrier and an active component supported on the carrier, wherein the active component contains at least one of Group IA elements, Group IIA elements, Group IIIA elements, Group IVB elements, Group VIB elements and Group VIII elements; Preferably, the active component in the supported catalyst is at least one of the elements of Group IVB; More preferably, the loading amount of the active component in the supported catalyst is 0.1-30%, preferably 0.5-25%.

6. The catalytic composition according to claim 5, wherein The carrier in the supported catalyst is selected from at least one of molecular sieves, alumina, silicon oxide and activated carbon; and / or In the supported catalyst, The Group IA element is selected from sodium and / or potassium, preferably sodium; and / or The Group IIA element is selected from magnesium and / or calcium, preferably calcium; and / or The group IIIA element is selected from boron and / or gallium, preferably gallium; and / or The Group IVB element is selected from titanium and / or zirconium, preferably zirconium; and / or The Group VIB element is selected from chromium and / or molybdenum, preferably chromium; and / or The Group VIII element is at least one selected from iron, cobalt and nickel, preferably cobalt.

7. The catalytic composition according to any one of claims 1 to 6, wherein: The specific surface area of ​​the first auxiliary component is 1-50m 2 / g, preferably 5-45m 2 / g; and / or The specific heat capacity of the first auxiliary component is 700-910 J / (Kg*°C), preferably 750-860 J / (Kg*°C); and / or The reduction peak value of the first auxiliary component is 200-300°C.

8. The catalytic composition according to any one of claims 1 to 7, wherein: The preparation method of the first auxiliary agent component comprises: using a first silicon and / or aluminum compound as a carrier, contacting with a modifying element solution, controlling the pH value to be 6-9, obtaining a first auxiliary agent component precursor, drying and calcining to obtain the first auxiliary agent component; preferably, The first auxiliary agent component precursor is dried at 60-150° C. for 0.5-8 h, and calcined at 1000-1400° C. for 4-48 h.

9. Use of the catalytic composition according to any one of claims 1 to 8 in a dehydrogenation reaction, preferably in the dehydrogenation of light alkanes.

10. A method for dehydrogenating light alkanes, characterized in that: The method comprises contacting a low carbon alkane with a catalytic composition according to any one of claims 1 to 8, preferably, The contact reaction conditions include: temperature of 500-650°C, pressure of 0.05-0.15 MPa, mass space velocity of 0.5-5 h -1 . and / or The low carbon alkane is selected from alkanes below C6, preferably propane.

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