Alkane dehydrogenation reaction method, heating accelerant and preparation method and application thereof

Abstract

The invention relates to the field of heating promoters, and discloses an alkane dehydrogenation reaction method, a heating promoter and a preparation method and application thereof. The heating accelerant disclosed by the invention comprises the following components in percentage by weight: 1) 2 to 10 weight percent of Cu oxide based on CuO; 2) 8 wt%-20 wt% of Ca oxide based on CaO; 3) 0.01 wt%-3 wt% of an oxide of the IVB group element based on the tetravalent oxide of the IVB group element; and 4) 70 wt%-85 wt% of a carrier. The heating accelerant is high in heat release capacity and good in stability, is applied to the alkane dehydrogenation reaction, can enable the temperature of a reaction bed layer to be more uniform, can reduce generation of carbon deposition in the reaction process, and enhances the carbon deposition resistance of a catalyst, so that the raw material conversion rate of the alkane dehydrogenation reaction is increased, and the heating accelerant has a good industrial prospect.

Description

Technical Field

[0001] This invention relates to the field of heat-generating accelerators, specifically to a heat-generating accelerator, its preparation method and application, and a method for alkane dehydrogenation reaction. Background Technology

[0002] Propylene is the world's second-largest petrochemical product after ethylene, primarily used in the production of polypropylene and propylene oxide. Propane dehydrogenation (PDH) has become a popular propylene production process in recent years. Using propane as a feedstock, it dehydrogenates propane under the action of a catalyst to produce polymer-grade propylene. Compared to other propylene production processes, it has gained industry popularity due to the following advantages: First, it produces a single product from a single feedstock, resulting in a shorter process flow, simpler equipment, and lower investment and operating costs compared to traditional refinery by-products and steam cracking processes. Second, compared to coal-to-olefins, propane dehydrogenation requires lower investment, consumes less energy, and is relatively environmentally friendly. Third, propane dehydrogenation can convert low-value propane into high-value propylene, diversifying products and increasing added value. Among propane dehydrogenation processes, based on current global and domestic technology transfer, application, and equipment investment, Lummus's Catofin process and UOP's Oleflex process have significant advantages, each accounting for approximately 48%. The Catofin process boasts advantages such as high alkane conversion rate, good product selectivity, strong feedstock adaptability, and high unit online rate. It is easy to add more parallel reactors to the unit, facilitating capacity expansion and improving economies of scale. However, due to the strong endothermic nature of dehydrogenation, it cannot utilize inter-stage heating like a series reactor. Therefore, effectively utilizing heat utilization, heat balance, or heat supplementation to improve conversion efficiency and reduce energy consumption is crucial.

[0003] A common method for heat balance and reuse is to fully utilize the heat generated during catalyst regeneration. For example, CN 105120997A describes a process where an exothermic catalyst regeneration reaction transfers heat to an integrated fluidized bed reactor, using at least a portion of the transferred heat to initiate an endothermic reaction for alkane dehydrogenation. Some recent patents disclose the use of exothermic promoters as additives in the catalyst bed.

[0004] CN 108300430B discloses an exothermic catalytic agent for alkane dehydrogenation, its preparation method, and its application method, relating to the field of alkane dehydrogenation, and particularly an exothermic catalytic agent for alkane dehydrogenation reactions, along with its preparation and application methods. Its composition is 10–35 wt% CaO, 50–85 wt% Al₂O₃, 5–30 wt% CuO, and 0–3 wt% metal oxides selected from Group VIII, Group IIB, Group IIIB, and Group VIIB. This catalytic agent stores heat during the catalyst regeneration stage and releases heat during the catalytic reaction, improving the stability of the process. However, the improved temperature drop effect is not disclosed, and the reaction performance is not ideal.

[0005] CN 113388376B discloses an alkane dehydrogenation heating aid, its preparation method, and its application. It is mainly prepared from CaO, CuO, and Al2O3, with the following weight proportions: 3590 parts CaO, 1040 parts CuO, and 540 parts Al2O3. In this alkane dehydrogenation heating aid, Cu mainly exists in the forms of CaCu2O3 and Ca2CuO3, with a Ca atom to Al atom ratio ≥6 / 7. The high Ca content undoubtedly weakens the main Al2O3 content. Since αAl2O3 inert ceramic balls can store heat in the dehydrogenation reaction, Al2O3 is also very important in the heating element.

[0006] In view of the above problems, it is imperative to develop a heat-generating promoter that can effectively reduce the drastic changes in reaction temperature, thereby reducing the amount of carbon deposits on the dehydrogenation catalyst. Summary of the Invention

[0007] The purpose of this invention is to overcome the problem of drastic temperature changes in the catalyst bed during alkane dehydrogenation reactions in existing technologies, and to provide a heat-generating promoter, its preparation method, its application, and a method for alkane dehydrogenation reactions.

[0008] 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.

[0009] The present invention provides a heat-generating agent, which, by weight percentage, contains: 1) 2 wt% to 10 wt% Cu oxide, based on CuO; 2) 8 wt% to 20 wt% Ca oxide, based on CaO; 3) 0.01 wt% to 3 wt% of IVB element oxide, based on tetravalent oxides of group IVB elements; and 4) 70 wt% to 85 wt% carrier.

[0010] In this invention, the range of possible supports is quite wide. This is an illustrative example, but it does not limit the scope of the invention. For example, the support may be selected from one or more of Al2O3, SiO2, SiC, and SiO2-Al2O3.

[0011] According to a preferred embodiment of the present invention, the carrier is Al2O3, and the heating accelerator contains CaAl. 12 O 19 Crystal phase structure. Exothermic accelerators with the aforementioned composition and crystal phase structure have strong exothermic ability (exothermic ability is the amount of heat provided by the exothermic accelerator to the reactor) and good stability.

[0012] In this invention, CaAl in the heat-generating accelerator 12 O 19 The molar ratio of CaAl to Al2O3 can be selected over a wide range. This example illustrates one implementation method, but does not limit the scope of the invention. According to a preferred embodiment of the invention, CaAl... 12 O 19 The molar ratio of CaAl to Al₂O₃ is 1:(0.1–0.5). (The text then abruptly shifts to a seemingly unrelated topic about CaAl content.) 12 O 19 The heat-generating accelerator with a molar ratio of Al2O3 has strong exothermic ability and good stability.

[0013] In this invention, the group IVB elements in the heat-generating accelerator have advantages such as enhancing the dispersibility of Cu oxide and regulating the interaction between Cu oxide and other components. The range of selectable group IVB elements is relatively wide. This invention illustrates one embodiment, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the group IVB elements are selected from one or more of Ti, Zr, and Hf.

[0014] In this invention, Cu oxide, Ca oxide, and element IVB work synergistically in the dehydrogenation reaction of alkane, offering advantages such as regulating the heat balance of the reaction and improving the selectivity of raw materials. The weight ratio of Ca oxide to element IVB oxide has a wide range of possible values. This invention exemplifies one implementation method but does not limit the scope of the invention. According to a preferred embodiment of the invention, the weight ratio of Ca oxide to element IVB oxide is 4–20:1. The heat-generating promoter containing the aforementioned substances exhibits strong exothermic ability and good stability.

[0015] In this invention, the heat-generating accelerators having the aforementioned technical features can all achieve the purpose of this invention. The combination mode of Ca oxide, IVB element oxide and Cu oxide with the carrier can be adjusted as needed. According to a preferred embodiment of this invention, the heat-generating accelerator contains a carrier modified with Ca oxide and IVB element oxide and Cu oxide loaded on the modified carrier.

[0016] According to a preferred embodiment of the present invention, modifying a support such as Al₂O₃ with Ca oxide and oxides of the IVB element can give the modified support a specific crystal phase structure, such as CaAl. 12 O 19 Crystal phase structure. Having a specific crystal phase structure, such as CaAl. 12 O 19 The exothermic promoter with a crystalline structure has strong exothermic ability and good stability.

[0017] According to a preferred embodiment of the present invention, the carrier is a molded carrier, and its morphology is one or more of the following: cylinder, trilobal strip, tetralobal strip, and sphere. Molded carriers have high heat transfer efficiency and can prevent the generation of localized hot spots. In the embodiments of the present invention, a cylindrical molded carrier is used as an example to illustrate the advantages of the present invention, but this does not limit the scope of the invention.

[0018] In this invention, any heat-generating accelerator with the aforementioned characteristics can achieve the purpose of this invention. The range of selectable contents for each substance is relatively wide. The following is an illustrative description, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the heat-generating accelerator contains, by weight percentage: 3 wt% to 8 wt% of Cu oxide, calculated as CuO.

[0019] According to a preferred embodiment of the present invention, the heat-generating agent contains, by weight percentage, 10 wt% to 18 wt% of Ca oxide, calculated as CaO.

[0020] According to a preferred embodiment of the present invention, the heat-generating agent contains, by weight percentage: 0.5 wt% to 2.5 wt% of the oxide of the IVB element, based on the tetravalent oxide of the IVB element.

[0021] As long as a heat-generating accelerator with the aforementioned technical features of this invention can be obtained, there are no special requirements for its preparation method. In view of this invention, an exemplary preparation method for a heat-generating accelerator is provided, which includes: loading a carrier into contact with a Group IVB element source, a Ca source and a Cu source, followed by drying and calcination.

[0022] In the preparation of the heat-generating accelerator, commonly used carriers can be used in this invention. The carrier can be selected according to the existing technology. For example, the carrier is selected from one or more of Al2O3, SiO2, SiC, and SiO2-Al2O3.

[0023] According to a preferred embodiment of the present invention, in the preparation process of the heat-generating accelerator, Al2O3 is used as the carrier, and the prepared heat-generating accelerator contains CaAl. 12 O 19 Crystal structure.

[0024] According to a preferred embodiment of the present invention, in the preparation process of the heat-generating promoter, the carrier is a molded carrier with a morphology of one or more of the following: cylinder, trilobal strip, tetralobal strip, and sphere. Molded carriers have high heat transfer efficiency and can prevent the generation of localized hot spots. In the embodiments of the present invention, a cylindrical molded carrier is used as an example to illustrate the advantages of the present invention, but this does not limit the scope of the present invention.

[0025] In the preparation process of the heat-generating accelerator, as long as the prepared heat-generating accelerator contains the required Cu oxide, Ca oxide, and IVB element oxide, there are no special requirements for the selection of Cu source, Ca source, and IVB element source. The following is an illustrative description, but it does not limit the scope of the invention. For example, the Cu source, Ca source, and IVB element source each include one or more of the following: nitrate, sulfate, hydrochloride, acetate, phosphate, and acetylacetonate of the corresponding element.

[0026] In this invention, the range of Group IVB elements that can be selected during the preparation of the heat-generating accelerator is relatively wide. One embodiment is illustrated by way of example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the Group IVB elements are selected from one or more of Ti, Zr and Hf.

[0027] In the embodiments of the present invention, copper nitrate is used as the Cu source; calcium nitrate is used as the Ca source; and among the Group IVB element sources, titanium chloride is used as the Ti source, zirconium nitrate is used as the Zr source, and hafnium chloride is used as the Hf source. This exemplifies the advantages of the present invention but does not limit its scope.

[0028] In this invention, drying does not affect the performance of the heat-generating accelerator during the preparation process. Commonly used drying conditions can be used in this invention. This is an illustrative example, but it does not limit the scope of the invention. For example, the drying conditions include: a drying temperature of 80℃ to 150℃; and a drying time that is adjusted according to the drying temperature, for example, a drying time of 6h to 24h.

[0029] In this invention, the calcination conditions during the preparation of the heat-generating accelerator can be selected from a wide range. One embodiment is illustrated, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the calcination conditions include: a calcination temperature of 700℃ to 1400℃; and a calcination time adjusted according to the calcination temperature, etc., for example, a calcination time of 4 to 24 hours.

[0030] According to a preferred embodiment of the present invention, the preparation method of the heat-generating promoter includes: (1) mixing a carrier, a Ca source and a group IVB element source for a first contact, followed by drying and calcination to obtain a modified carrier; (2) loading a Cu source onto the modified carrier through a second contact, followed by drying and calcination.

[0031] In this invention, during the preparation of the heat-generating accelerator, the support used in step (1) includes Al2O3, etc. According to a preferred embodiment of this invention, the prepared modified support contains a specific crystal phase structure, such as CaAl. 12 O 19 Crystal structure.

[0032] In the preparation process of the heat-generating promoter, as long as a shaped modified carrier can be prepared in step (1), there are no special requirements for the specific process of step (1). This is an example of an implementation method, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, in step (1), the carrier, Ca source and group IVB element source are mixed, kneaded, and allowed to stand for curing, and then dried and calcined to obtain a shaped modified carrier.

[0033] In this invention, during the preparation of the heat-generating accelerator, as is known to those skilled in the art, using a molded modified carrier can better ensure the performance of the heat-generating accelerator. For molding, a binder and a co-solvent are generally introduced. The molding method is prior art and is illustrated by way of example, but does not limit the scope of this invention. For example, the molding method includes mixing the carrier, Ca source and IVB element source, binder and co-solvent, and extruding them into strips; the binder is selected from one or more of guar gum powder, hydroxypropyl cellulose, starch and clay; the co-solvent is selected from one or more of nitric acid, hydrochloric acid, citric acid and dichloroacetic acid.

[0034] In the preparation process of the heat-generating accelerator, there are no special requirements for the amount of binder and co-solvent introduced for molding purposes; they can be selected according to existing technology. This invention will not elaborate on these requirements.

[0035] In the preparation process of the heat-generating accelerator, the static curing after molding in step (1) can prolong the interaction time of the molding components and increase the strength of the carrier, so that the heat-generating accelerator prepared has strong heat release capacity and good stability. According to a preferred embodiment of the present invention, the static curing conditions include: temperature 15℃~30℃, for example, temperature 20℃ or 25℃.

[0036] According to a preferred embodiment of the present invention, the resting and conditioning time is 16h to 24h, for example, 18h, 20h, or 22h. The embodiments of the present invention exemplify the advantages of resting and conditioning at 30°C for 16 hours, but do not limit the scope of the invention.

[0037] In this invention, there are no special requirements for the morphology of the modified carrier formed in step (1). This is merely an illustrative example and does not limit the scope of the invention. For example, the morphology of the modified carrier formed in step (1) can be one or more of the following: cylinder, trilobal strip, tetralobal strip, and sphere. In the embodiments of this invention, the cylindrical morphology of the modified carrier is used as an illustrative example to illustrate the advantages of the invention, but this does not limit the scope of the invention.

[0038] In the preparation process of the heat-generating accelerator, as long as the Cu source can be loaded onto the modified carrier through the second contact, there are no special requirements for the method of loading the Cu source onto the modified carrier through the second contact in step (2). This is an example of an implementation method, but it does not limit the scope of the invention. For example, in step (2), the second contact can be an impregnation method, a precipitation method, a spraying method, or a mixing method.

[0039] According to a preferred embodiment of the present invention, the Cu source is loaded onto the modified carrier through a second contact in step (2) by an impregnation method, preferably an equal-volume impregnation method.

[0040] In this invention, the drying process in steps (1) and (2) of the heat-generating accelerator preparation does not affect the performance of the heat-generating accelerator. Commonly used drying conditions can be used in this invention. This is an illustrative example, but does not limit the scope of the invention. For example, the drying conditions in steps (1) and (2) include: a drying temperature of 80℃ to 150℃; and a drying time adjusted according to the drying temperature, for example, a drying time of 6h to 24h. In the embodiments of this invention, the drying conditions in steps (1) and (2) are both 120℃ and 12 hours, which illustrate the advantages of this invention, but do not limit the scope of the invention.

[0041] In this invention, the calcination conditions in steps (1) and (2) of the preparation process of the heat-generating accelerator have a wide range of selectable options. This invention exemplifies one implementation method but does not limit the scope of the invention. According to a preferred embodiment of the invention, the calcination conditions in steps (1) and (2) include: a calcination temperature of 700℃ to 1400℃; and a calcination time adjusted according to the calcination temperature, for example, a calcination time of 4 to 24 hours. In the embodiments of the invention, the calcination conditions in steps (1) and (2) are both 1200℃ and 6 hours, which exemplifies the advantages of the invention but does not limit the scope of the invention.

[0042] This invention provides the application of the heat-generating accelerator described herein in the dehydrogenation reaction of alkane, preferably an alkane with C6 or less, more preferably propane.

[0043] This invention provides a method for alkane dehydrogenation reaction, wherein the alkane dehydrogenation is carried out in the presence of the exothermic promoter and the alkane dehydrogenation catalyst described in this invention.

[0044] In this invention, the conditions for the alkane dehydrogenation reaction are available in a wide range. One embodiment is illustrated, but this does not limit the scope of the invention. According to a preferred embodiment of the invention, the conditions for the alkane dehydrogenation reaction include: the volume ratio of the heat-generating promoter to the alkane dehydrogenation catalyst is 0.2 to 1.2:1.

[0045] According to a preferred embodiment of the present invention, the conditions for the alkane dehydrogenation reaction include a temperature of 500°C to 650°C.

[0046] According to a preferred embodiment of the present invention, the conditions for the alkane dehydrogenation reaction include a pressure of 0.05-0.15 MPa.

[0047] According to a preferred embodiment of the present invention, the conditions for the alkane dehydrogenation reaction include: a mass hourly space velocity (HHSV) of 0.5-5 h⁻¹. -1 .

[0048] According to a preferred embodiment of the present invention, the conditions for the alkane dehydrogenation reaction include: the alkane is a C6 or less alkane, more preferably propane.

[0049] In the embodiments of the present invention, the conditions for the alkane dehydrogenation reaction are as follows: a volume ratio of exothermic promoter to alkane dehydrogenation catalyst of 1:1, a temperature of 600°C, a pressure of 0.1 MPa, and a mass hourly space velocity of 1 h⁻¹. -1 The use of propane as an example of alkanes illustrates the advantages of the invention, but does not limit the scope of the invention.

[0050] In this invention, the performance of the heating material is not affected after the reaction-regeneration cycle. Commonly used regeneration methods can achieve the purpose of this invention. There are no special requirements for regeneration conditions. One embodiment is illustrated, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the regeneration conditions are a temperature of 500℃-700℃ and / or 5-50 ml / min in an air atmosphere, and / or a time of 1h-4h. In an embodiment of this invention, in order to test the performance of the heating material, the heating material is regenerated and recycled after undergoing an alkane dehydrogenation reaction. The regeneration conditions are charring at 600℃ and 20 ml / min in an air atmosphere for 2h.

[0051] In this invention, commonly used alkane dehydrogenation catalysts can be used, and there are no special requirements for the composition of the alkane dehydrogenation catalyst. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the alkane dehydrogenation catalyst includes a support and an active metal component, wherein the active metal is selected from one or more of chromium, potassium, and zirconium, and the support is selected from one or more of alumina, silicon oxide, zirconium oxide, and silicon carbide. In the embodiments of the invention, the alkane dehydrogenation catalyst includes a support and an active metal component, wherein the active metal includes chromium, potassium, and zirconium, and the support is alumina.

[0052] According to a preferred embodiment of the present invention, the dehydrogenation catalyst comprises: K2O 0.1-5 wt%, ZrO2 1-10 wt%, Cr2O3 5-20 wt%, and Al2O3 70-90 wt%.

[0053] In this invention, any alkane dehydrogenation catalyst having the aforementioned composition can achieve the purpose of this invention. There are no special requirements for the preparation method of the alkane dehydrogenation catalyst. An embodiment is illustrated by way of example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the preparation method of the alkane dehydrogenation catalyst includes: preparing an impregnation solution containing an active metal, impregnating and contacting it with a support, followed by solid-liquid separation, drying, and calcination.

[0054] In this invention, the conditions for impregnation contact, solid-liquid separation, drying, and calcination in the preparation process of the alkane dehydrogenation catalyst can be selected according to existing technologies, and will not be described in detail in this invention.

[0055] The exothermic accelerator of this invention has strong exothermic ability and good stability. When applied to the dehydrogenation reaction of alkane, it can make the temperature of the reaction bed more uniform, reduce the formation of carbon deposits during the reaction, and enhance the anti-coking performance of the catalyst, thereby improving the raw material conversion rate of the dehydrogenation reaction of alkane and showing good industrialization prospects. Attached Figure Description

[0056] Figure 1 This is the XRD pattern of the heat-generating agent in Example 1;

[0057] Figure 2 This is the XRD pattern of the heat-generating accelerator in Comparative Example 1. Detailed Implementation

[0058] The present invention will now be described in detail through examples and comparative examples.

[0059] The X-ray diffraction characterization tests were performed on a Bruker D8 diffractometer manufactured by Bruker GmbH, Germany, equipped with copper K-type radiation (λ = 0.154 nm). The diffractometer was scanned at 40 kV and 40 mA, with a 2D scanning range of 5-80°.

[0060] Among them, CaAl 12 O 19 The molar ratio of Al2O3 was obtained by quantitative analysis of the XRD patterns using the Rietveld method.

[0061] Carbon deposits were measured by thermogravimetric analysis: using a TA-STDQ600 thermal analyzer from TA Instruments, USA, a 20mg sample was placed in an airflow of 40ml / min and heated from room temperature to 700℃ at a rate of 20℃ / min. The weight loss curve was detected, and the weight loss was the carbon deposits.

[0062] Example 1

[0063] 400g of boehmite (calculated as Al2O3), 10g of guar gum powder, 15g of nitric acid (mass concentration of nitric acid 65-68 wt%), 17.42g of zirconium nitrate pentahydrate, and 252.66g of calcium nitrate tetrahydrate were weighed. The boehmite and guar gum powder were first mixed at room temperature for 20 minutes. Then, a mixed solution of nitric acid, zirconium nitrate pentahydrate, calcium nitrate tetrahydrate, and water was added, and the mixture was stirred and kneaded for another 20 minutes until it formed a dough-like consistency. The dough was then extruded into cylindrical shapes. Sample I was cured at 30℃ for 16 hours, dried in an oven at 120℃ for 12 hours, and calcined at 1200℃ for 6 hours to obtain sample II after high-temperature calcination.

[0064] Then, weigh 93 grams of calcined sample II, dissolve 21.26 grams of copper nitrate trihydrate in water, place the calcined sample II in the solution for equal volume impregnation, dry at 120°C for 12 hours, and calcine at 1200°C for 6 hours to obtain the desired heat-generating accelerator.

[0065] The resulting heat-generating agent contains, by weight percentage, 7 wt% Cu oxide, 12 wt% Ca oxide, 1 wt% element IVB oxide, and 80 wt% Al2O3.

[0066] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.33.

[0067] Figure 1 This is the XRD pattern of the heat-generating accelerator in Example 1, from... Figure 1 It can be seen that the carrier composition of the heat-generating accelerator includes not only Al2O3 but also CaAl. 12 O 19 .

[0068] Example 2

[0069] The sample was prepared according to the method of Example 1, except that 17.42 g of zirconium nitrate pentahydrate and 252.66 g of calcium nitrate tetrahydrate were replaced with 5.93 g of titanium chloride and 169.28 g of calcium nitrate tetrahydrate. The amounts of copper nitrate trihydrate and boehmite were changed to 9.11 g and 442.5 g, respectively. Sample II was taken as 97 g.

[0070] The resulting heat-generating accelerator contains 3 wt% CuO, 8 wt% CaO, 0.5 wt% TiO2, and 88.5 wt% carrier by weight percentage.

[0071] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.34.

[0072] XRD pattern of the heat-generating accelerator in Example 2 and Figure 1 similar.

[0073] Example 3

[0074] The sample was prepared according to the method of Example 1, except that 17.42 g of zirconium nitrate pentahydrate was replaced with 19.02 g of hafnium chloride; and the amounts of copper nitrate trihydrate, boehmite, and calcium nitrate tetrahydrate were changed to 27.33 g, 352.5 g, and 379 g, respectively. Sample II was prepared in 91 g form.

[0075] The resulting heat-generating agent contains, by weight percentage, 9 wt% CuO, 18 wt% CaO, 2.5 wt% HfO2, and 70.5 wt% carrier.

[0076] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.28.

[0077] XRD pattern of the heat-generating accelerator in Example 3 and Figure 1similar.

[0078] Example 4

[0079] The sample was prepared according to the method of Example 1, except that 17.42 g of zirconium nitrate pentahydrate was replaced with 8.71 g of zirconium nitrate pentahydrate. The amount of boehmite was changed to 402.5 g. Sample II was prepared with 93 g.

[0080] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% CaO, 0.5 wt% ZrO2, and 80.5 wt% carrier by weight percentage.

[0081] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.4.

[0082] XRD pattern of the heat-generating accelerator in Example 4 and Figure 1 similar.

[0083] Example 5

[0084] The sample was prepared according to the method of Example 1, except that the amount of copper nitrate trihydrate added was 6.08 g. The amount of boehmite was changed to 425 g. Sample II was taken as 98 g.

[0085] The resulting heat-generating agent contains, by weight percentage, 2 wt% CuO, 12 wt% CaO, 1 wt% ZrO2, and 85 wt% carrier.

[0086] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.36.

[0087] XRD pattern of the heat-generating accelerator in Example 5 and Figure 1 similar.

[0088] Example 6

[0089] The sample was prepared according to the method of Example 1, except that the amount of zirconium nitrate pentahydrate added was 45.29 g. The amount of boehmite was changed to 392 g. Sample II was prepared with 93 g.

[0090] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% CaO, 2.6 wt% ZrO2, and 78.4 wt% carrier by weight percentage.

[0091] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.37.

[0092] XRD pattern of the heat-generating accelerator in Example 6 and Figure 1 similar.

[0093] Example 7

[0094] The sample was prepared according to the method in Example 1, except that the amount of calcium nitrate tetrahydrate was changed to 105.28 g, and the amount of boehmite was changed to 435 g. Sample II was prepared in the form of 93 g.

[0095] The resulting heat-generating agent contains 7 wt% CuO, 5 wt% CaO, 1 wt% ZrO2, and 87 wt% carrier by weight percentage.

[0096] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.39.

[0097] XRD pattern of the heat-generating accelerator in Example 7 and Figure 1 similar.

[0098] Example 8

[0099] Weigh 400g of boehmite (calculated as Al2O3), 10g of guar gum powder, and 15g of nitric acid (nitric acid concentration of 65-68wt%). The boehmite and guar gum powders are first mixed at room temperature for 20 minutes. Then, a mixture of nitric acid and water is added, and the mixture is stirred and kneaded for another 20 minutes until it forms a dough-like consistency. The dough is then extruded into cylindrical shapes. Sample I is then cured at 30℃ for 16 hours, dried in an oven at 120℃ for 12 hours, and calcined at 1200℃ for 6 hours to obtain sample III after high-temperature calcination.

[0100] Then weigh 93g of calcined sample III, 17.42g of zirconium nitrate pentahydrate and 252.66g of calcium nitrate tetrahydrate, and dissolve 21.26g of copper nitrate trihydrate in water. Place calcined sample II in the solution and immerse it in an equal volume. Then dry it at 120℃ for 12 hours and calcin it at 1200℃ for 6 hours to obtain the desired heat-generating accelerator.

[0101] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% CaO, 1 wt% ZrO2, and 80 wt% carrier by weight percentage.

[0102] The heat-inducing agent does not contain CaAl. 12 O 19 Crystal structure.

[0103] Example 9

[0104] The sample was prepared according to the method in Example 1, except that after molding, sample I was left to stand at 30°C for 4 hours.

[0105] The resulting heat-inducing agent contains CaAl in its carrier. 12 O 19 ,CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:0.43.

[0106] XRD pattern of the heat-generating agent in Example 9 and Figure 1 similar.

[0107] Comparative Example 1

[0108] The preparation process did not include Ca or IVB oxides, and the amount of pseudoboehmite used was 465g. The remaining components, contents, and preparation process were the same as in Example 1. By weight percentage, the resulting heat-generating accelerator contained 7wt% CuO and 93wt% carrier.

[0109] The heat-inducing agent does not contain CaAl 12 O 19 Crystal structure.

[0110] Figure 2 This is the XRD pattern of the heating accelerator in Comparative Example 1, from... Figure 2 It can be seen that the carrier of the heat-inducing agent does not contain CaAl. 12 O 19 Its crystal structure consists only of Al2O3.

[0111] Comparative Example 2

[0112] Except for the absence of IVB oxide, the amount of pseudoboehmite used in the preparation was 405g. The remaining components, contents, and preparation process were the same as in Example 1.

[0113] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% CaO, and 81 wt% carrier by weight percentage.

[0114] The heat-inducing agent does not contain CaAl. 12 O 19 Crystal structure.

[0115] XRD pattern of the heat-generating accelerator in Comparative Example 2 and Figure 2 similar.

[0116] Comparative Example 3

[0117] The preparation method is the same as in Example 1, except that 17.42 g of zirconium nitrate pentahydrate is replaced with 15.93 g of cerium ammonium nitrate.

[0118] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% CaO, 1 wt% CeO2, and 80 wt% carrier by weight percentage.

[0119] The heat-inducing agent does not contain CaAl. 12 O 19 Crystal structure.

[0120] XRD pattern of the heat-generating accelerator in Comparative Example 3 and Figure 2 similar.

[0121] Comparative Example 4

[0122] The preparation was carried out according to the method of Example 1, except that 252.66g of calcium nitrate tetrahydrate was replaced with 102.24g of barium nitrate.

[0123] The resulting heat-generating agent contains 7 wt% CuO, 12 wt% BaO, 1 wt% ZrO2, and 80 wt% carrier by weight percentage.

[0124] The heat-inducing agent does not contain CaAl. 12 O 19 Crystal structure.

[0125] XRD pattern of the heat-generating accelerator in Comparative Example 4 and Figure 2 similar.

[0126] Performance evaluation of heat-generating accelerators

[0127] The preparation method of propane dehydrogenation catalyst includes: weighing 52.66 g of chromium nitrate hexahydrate, 2.15 g of potassium nitrate, and 6.96 g of zirconium nitrate pentahydrate, adding them to 100 mL of deionized water, then adding 87 g of γ-alumina support, adjusting the pH of the solution to 3.6 with 2.5% ammonia, then immersing the sample in an 80°C water bath for 1 hour, removing the sample for filtration, drying it in a 120°C oven for 16 hours, and then calcining the sample in a muffle furnace at 800°C for 6 hours to obtain the desired catalyst.

[0128] The heat-generating accelerators prepared in Examples 1-9 and Comparative Examples 1-4 were mixed with propane dehydrogenation catalysts at a volume ratio of 1:1, and their performance was evaluated. The performance evaluation method was as follows:

[0129] Pure propane gas is fed into the preheating zone via a mass flow meter to regulate its flow rate, and then enters the reaction zone. Both the heating and reaction sections of the reactor are heated by electric heating wires. The reactor operates at a temperature of 600℃, a pressure of 0.1 MPa, and a mass hourly space velocity (HHSV) of 1 h⁻¹.-1 Under the specified conditions, propane, a mixture of heat-generating accelerator and catalyst, and other components were reacted in an adiabatic manner for 10 minutes. The resulting gas was then condensed and analyzed using an Agilent 7890A gas chromatograph. A heating coupler was placed in the middle of the dehydrogenation catalyst bed to monitor the temperature changes during the reaction in real time. The temperature drop was the decrease in temperature during the reaction in the adiabatic bed reactor and was read directly from the temperature display.

[0130] The conversion rate of propane (%) = (mass of propane in reactants / mass of propane in reaction products) ÷ mass of propane in reactants × 100%;

[0131] Selectivity of propylene (%) = Actual yield of propylene ÷ Theoretical yield of propylene × 100%, by mass.

[0132] The gaseous raw material is a commercially available product from Nanjing Tianze Company.

[0133] Table 1 shows the temperature drop, conversion rate, selectivity, carbon deposition, and results after 10 min of adiabatic contact reaction of propane, heating material, and propane dehydrogenation catalyst. The performance evaluation results are also shown in Table 1.

[0134] Table 1

[0135]

[0136] As can be seen from the results in Table 1, the application of the heat-generating promoter of the present invention in the alkane dehydrogenation reaction can make the temperature of the reaction bed more uniform, thereby reducing the formation of carbon deposits during the reaction, enhancing the anti-coking performance of the catalyst, and thus improving the feed conversion rate of the alkane dehydrogenation reaction.

[0137] 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 heat-generating agent, characterized in that, The heat-generating agent contains, by weight percentage: 1) Cu oxides, calculated as CuO, ranging from 2 wt% to 10 wt%; 2) 8 wt% to 20 wt% of Ca oxides, calculated as CaO; 3) 0.01 wt% to 3 wt% of IVB element oxides, calculated as tetravalent oxides of group IVB elements; 4) 70wt%~85wt% carrier.

2. The heat-generating agent according to claim 1, wherein, The carrier is Al2O3, and the heat-generating accelerator contains CaAl. 12 O 19 Crystal structure, preferably CaAl 12 O 19 The molar ratio of Al2O3 to Al2O3 is 1:(0.1–0.5); and / or The group IVB elements are selected from one or more of Ti, Zr, and Hf; and / or The weight ratio of Ca oxide to oxide of element IVB is 4–20:

1.

3. The heat-generating agent according to claim 1 or 2, wherein, The heat-generating accelerator contains a carrier modified with Ca oxide and oxides of element IVB, and Cu oxide supported on the modified carrier; Preferably, The support is Al2O3, and the modified support contains CaAl. 12 O 19 Crystal phase structure; and / or The carrier is a molded carrier, and its shape is one or more of the following: cylinder, trilobal strip, tetralobal strip, and sphere.

4. The heat-inducing agent according to any one of claims 1-3, wherein, The heat-generating agent contains, by weight percentage: Based on CuO, 3 wt% to 8 wt% Cu oxide; and / or Based on CaO, 10 wt% to 18 wt% of Ca oxides; and / or Based on tetravalent oxides of element IVB, 0.5wt% to 2.5wt% of element IVB oxides.

5. A method for preparing the heat-generating accelerator according to any one of claims 1-4, characterized in that, The method includes: The support was loaded by contacting a Group IVB element source, a Ca source, and a Cu source, followed by drying and calcination. Preferably, the carrier is Al2O3, and the prepared heat-generating accelerator contains CaAl. 12 O 19 Crystal phase structure; and / or The carrier is a molded carrier, and its shape is one or more of the following: cylinder, trilobal strip, tetralobal strip, and sphere; and / or Drying conditions include: a temperature of 80℃ to 150℃; and / or a time of 6 hours to 24 hours; and / or The roasting conditions include a temperature of 700℃ to 1400℃ and / or a time of 4 to 24 hours.

6. The method according to claim 5, wherein, The method includes: (1) The carrier, Ca source and group IVB element source are mixed and brought into first contact, then dried and calcined to obtain the modified carrier; (2) The Cu source is loaded onto the modified support through the second contact, and then dried and calcined.

7. The method according to claim 6, wherein, In step (1), Al2O3 is used as the support, and the prepared modified support contains CaAl. 12 O 19 Crystal phase structure; and / or In step (1), the carrier, Ca source and group IVB element source are mixed and kneaded into shape, left to stand for curing, and then dried and calcined to obtain the shaped modified carrier. Preferably, The conditions for static conditioning include: a temperature of 15℃~30℃, and / or a time of 16h~24h; and / or The morphology of the formed modified carrier is one or more of the following: cylinder, trilobal strip, tetralobal strip, and cylinder; and / or In step (2), the second contact is an impregnation method, a precipitation method, a spraying method or a mixing method, preferably an impregnation method, and more preferably an equal volume impregnation method.

8. The method according to claim 6 or 7, wherein, In steps (1) and (2), the drying conditions each include: a temperature of 80℃ to 150℃; and / or a time of 6h to 24h; and / or In steps (1) and (2), the roasting conditions each include: a temperature of 700℃ to 1400℃; and / or a time of 4 to 24 hours.

9. The application of the heat-generating accelerator according to any one of claims 1-4 in the dehydrogenation reaction of alkane, preferably an alkane with C6 or less, more preferably propane.

10. A method for dehydrogenation reaction of an alkane, characterized in that, This method involves carrying out alkane dehydrogenation in the presence of the exothermic accelerator described in any one of claims 1-4 and an alkane dehydrogenation catalyst, wherein the conditions for the alkane dehydrogenation reaction include: The volume ratio of the heating accelerator to the alkane dehydrogenation catalyst is 0.2–1.2:1; and / or Temperatures of 500℃ to 650℃; and / or Pressure is 0.05 MPa to 0.15 MPa; and / or Mass hourly space velocity is 0.5 h. -1 ~5h -1 ; The alkane is a C6 or smaller alkane, more preferably propane.

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