A regenerative catalyst and its preparation and use

Abstract

The application provides a heat storage type catalyst and preparation and application thereof, wherein, based on 100% of a dry base of the catalyst, the catalyst contains the following components by weight percentage: 10%-50% of a molecular sieve, 10%-40% of a heat storage material and 40%-80% of a carrier, the heat storage material has a thermal conductivity of 20-500 W / m*K and a specific heat capacity of 600-1200 J / kg*K. Through catalyst design, the application optimizes heat management, improves the yield and selectivity of products, optimizes energy utilization, provides strong support for efficient and stable operation of catalytic cracking, and promotes energy saving and environmental protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petroleum chemical industry, in particular, the present application relates to a heat storage type catalyst and its preparation and application. BACKGROUND

[0002] In the petroleum chemical industry, catalytic cracking of light hydrocarbons is one of the main methods for producing low-carbon olefins (ethylene, propylene, butylene). These low-carbon olefins are the basic raw materials for the synthesis of plastics, fibers and other chemicals, so improving their production efficiency and quality is crucial for the entire chemical industry. The reactor, as the core equipment for catalytic cracking, its performance directly affects the yield and quality of low-carbon olefins. The temperature of the catalyst bed in the reactor is a key factor affecting the reaction efficiency. The ideal temperature distribution should ensure that the catalyst maintains the best activity and selectivity throughout the reaction process, thereby maximizing the production of low-carbon olefins. However, in actual operation, due to the uneven transfer of heat and the rapid release of reaction heat, the catalyst bed often has uneven temperature distribution, which leads to local overheating, and further causes catalyst deactivation, increased side reactions or product distribution deviating from the expected.

[0003] To solve this problem, patent CN112812751A discloses a heat storage material for propane dehydrogenation to propylene process and its preparation method. The heat storage material is a supported composite metal oxide / support, and the support is selected from silica, alumina, activated carbon, silicon carbide and other heat storage materials, which can make the catalyst release heat during the reduction stage and air regeneration stage, making the bed temperature distribution more uniform, prolonging the catalyst life and reducing the energy consumption of the device. However, the catalyst has low activity, and only considers the heat storage capacity, without considering the heat conduction capacity, which may still cause uneven local heat of the catalyst.

[0004] Patent CN110479362A discloses a catalyst for producing low-carbon olefins, its preparation method and application. The catalyst is spray formed with molecular sieve, clay, inorganic matrix, binder and pore expander as raw materials, and the clay and inorganic matrix content of the raw materials is 48-75%, among which kaolin, montmorillonite and other materials have low thermal conductivity, and in the reaction process, the catalyst carrier is not easy to rapidly transfer heat to each part of the reactor, making it difficult to achieve uniform heat distribution.

[0005] In the current background, the petroleum chemical industry is facing the dual challenges of reducing carbon emissions and improving energy efficiency, and the present application can significantly improve energy utilization and reduce carbon emissions by introducing solid heat storage materials with high thermal conductivity and high specific heat capacity, which has broad industrial application prospects. SUMMARY

[0006] An object of the present application is to provide a heat storage type catalyst.

[0007] This catalyst combines heat storage materials, molecular sieves, clay, and binders, and has unique heat storage and heat release functions. During the reaction stage, the catalyst can maintain the reaction temperature by absorbing high-density heat inside; during the regeneration stage, it can enhance heat transfer at close range, store more heat, and reduce the need for external heat supplementation, thereby achieving uniform heat distribution and reducing the energy consumption of the device.

[0008] Another object of the present invention is to provide a method for preparing the regenerative catalyst.

[0009] Another object of the present invention is to provide the use of the regenerative catalyst.

[0010] To achieve the above objectives, in one respect, the present invention provides a heat storage catalyst, wherein, based on a dry basis of 100%, the catalyst (final product) contains at least the following weight percentage components: 10%-50% molecular sieve, 10%-40% heat storage material, and 40%-80% carrier, wherein the heat storage material has a thermal conductivity of 20-500 W / m·K and a specific heat capacity of 600-1200 J / kg·K.

[0011] According to some specific embodiments of the present invention, the catalyst, based on a dry basis of 100%, contains at least the following components by weight percentage: 15%-30% molecular sieve, 25%-40% heat storage material, and 40%-60% support.

[0012] According to some specific embodiments of the present invention, the support is SiO2 and / or Al2O3.

[0013] According to some specific embodiments of the present invention, SiO2 is derived from binders (silica sol, sodium silicate-acid mixture slurry) and / or clay (kaolin, montmorillonite, etc.); Al2O3 is derived from binders (alumina sol, boehmite-acid mixture slurry) and / or clay (kaolin, diatomaceous earth, etc.).

[0014] According to some specific embodiments of the present invention, the thermal conductivity of the heat storage material is 20-400 W / m·K, and the specific heat capacity is 700-1000 J / kg·K.

[0015] According to some specific embodiments of the present invention, the particle size of the heat storage material is 100-200 mesh.

[0016] According to some specific embodiments of the present invention, the heat storage material is selected from at least one of magnesium oxide, silicon carbide, aluminum nitride, silicon nitride, and boron nitride.

[0017] According to some specific embodiments of the present invention, the magnesium oxide has a thermal conductivity of 40-60 W / m·K and a specific heat capacity of 1000 J / kg·K.

[0018] According to some specific embodiments of the present invention, the magnesium oxide has a specific surface area of ​​30-200 m². 2 / g, specific pore volume 0.1~0.3cm 3 / g.

[0019] According to some specific embodiments of the present invention, the silicon carbide has a thermal conductivity of 120-200 W / m·K and a specific heat capacity of 750 J / kg·K.

[0020] According to some specific embodiments of the present invention, the silicon carbide has a specific surface area of ​​50-200 m². 2 / g, specific pore volume 0.1~0.3cm 3 / g.

[0021] According to some specific embodiments of the present invention, the aluminum nitride has a thermal conductivity of 140-180 W / m·K and a specific heat capacity of 740 J / kg·K.

[0022] According to some specific embodiments of the present invention, the aluminum nitride has a specific surface area of ​​10 to 100 m². 2 / g, specific pore volume 0.05~0.2cm 3 / g.

[0023] According to some specific embodiments of the present invention, the silicon nitride has a thermal conductivity of 20-30 W / m·K and a specific heat capacity of 700 J / kg·K.

[0024] According to some specific embodiments of the present invention, the silicon nitride has a specific surface area of ​​10 to 100 m². 2 / g, specific pore volume 0.1~0.4cm 3 / g.

[0025] According to some specific embodiments of the present invention, the boron nitride has a thermal conductivity of 200-400 W / m·K and a specific heat capacity of 750 J / kg·K.

[0026] According to some specific embodiments of the present invention, the boron nitride has a specific surface area of ​​50–200 m². 2 / g, specific pore volume 0.2~0.5cm 3 / g.

[0027] According to some specific embodiments of the present invention, the heat storage carrier material is in the shape of at least one of spherical, sheet-like or columnar.

[0028] According to some specific embodiments of the present invention, the molecular sieve is selected from at least one of Y-type molecular sieve, β-type molecular sieve and MFI molecular sieve.

[0029] According to some specific embodiments of the present invention, the molecular sieve is selected from at least one of REY molecular sieve, USY molecular sieve, REUSY molecular sieve, HY molecular sieve, REHY molecular sieve and ZSM-5 molecular sieve.

[0030] According to some specific embodiments of the present invention, the average grain size of the molecular sieve is 0.2 to 10 μm.

[0031] According to some specific embodiments of the present invention, the relative crystallinity of the molecular sieve is 90-99%.

[0032] On the other hand, the present invention also provides a method for preparing the regenerative catalyst, wherein the method includes the following steps:

[0033] In the step of preparing slurry A by mixing clay, binder, and water, the mass ratio of clay to binder is (0.5–0.9):(0.1–0.2), and the water is 1–2 times the total solid mass of this step.

[0034] In the step of mixing molecular sieve, clay, binder and water to obtain slurry B, the mass ratio of molecular sieve, clay and binder is (0.3~1.5):(0.1~0.3):(0.1~0.4), and the water is 1-2 times the total solid mass of this step;

[0035] In the step of mixing heat storage material, clay, binder and water to obtain slurry C, the mass ratio of heat storage material, clay and binder is (0.3~1.2):(0.1~0.65):(0.05~0.25), and the water is 1-2 times the total solid mass of this step;

[0036] The catalyst is obtained by mixing slurry A, slurry B and slurry C in a mass ratio of 1:(0.7-1.4):(0.4-1.6), spray drying and then calcining.

[0037] According to some specific embodiments of the present invention, in the step of preparing slurry A, the mass ratio of clay to binder is (0.8-0.9):(0.1-0.2).

[0038] According to some specific embodiments of the present invention, in the step of preparing slurry A, the mass ratio of clay to binder is (0.8-0.85):(0.1-0.2).

[0039] According to some specific embodiments of the present invention, in the step of preparing slurry B, the mass ratio of molecular sieve, clay and binder is (0.5-0.7):(0.1-0.2):(0.1-0.2).

[0040] According to some specific embodiments of the present invention, in the step of preparing slurry C, the mass ratio of heat storage material, clay and binder is (0.8~1.2):(0.1~0.2):(0.1~0.25).

[0041] According to some specific embodiments of the present invention, the mass ratio of slurry A: slurry B: slurry C is 1:(0.76-0.96):(1.08-1.52).

[0042] According to some specific embodiments of the present invention, the clay is selected from at least one of kaolin, sepiolite, attapulgite, palygorskite, montmorillonite, and diatomaceous earth.

[0043] According to some specific embodiments of the present invention, the kaolin has a thermal conductivity of 0.25 to 0.35 W / m·K and a specific heat capacity of 920 J / kg·K.

[0044] According to some specific embodiments of the present invention, the kaolin has a specific surface area of ​​10–30 m². 2 / g, specific pore volume 0.05~0.1cm 3 / g.

[0045] According to some specific embodiments of the present invention, the sepiolite has a thermal conductivity of 0.15 to 0.3 W / m·K and a specific heat capacity of 900 J / kg·K.

[0046] According to some specific embodiments of the present invention, the sepiolite has a specific surface area of ​​200-400 m². 2 / g, specific pore volume 0.3~0.5cm 3 / g.

[0047] According to some specific embodiments of the present invention, the attapulgite has a thermal conductivity of 0.1 to 0.2 W / m·K and a specific heat capacity of 850 J / kg·K.

[0048] According to some specific embodiments of the present invention, the attapulgite has a specific surface area of ​​125-200 m². 2 / g, specific pore volume 0.2~0.4cm 3 / g.

[0049] According to some specific embodiments of the present invention, the attapulgite has a thermal conductivity of 0.2 to 0.3 W / m·K and a specific heat capacity of 800 J / kg·K.

[0050] According to some specific embodiments of the present invention, the specific surface area of ​​the palygorskite is 250-400 m². 2 / g, specific pore volume 0.4~0.6cm 3 / g.

[0051] According to some specific embodiments of the present invention, the montmorillonite has a thermal conductivity of 0.25 to 0.5 W / m·K and a specific heat capacity of 850 J / kg·K.

[0052] According to some specific embodiments of the present invention, the montmorillonite has a specific surface area of ​​200–800 m². 2 / g, specific pore volume 0.4~0.6cm 3 / g.

[0053] According to some specific embodiments of the present invention, the diatomaceous earth has a thermal conductivity of 0.1 to 0.2 W / m·K and a specific heat capacity of 800 J / kg·K.

[0054] According to some specific embodiments of the present invention, the diatomaceous earth has a specific surface area of ​​20-30 m². 2 / g, specific pore volume 0.1~0.2cm 3 / g.

[0055] According to some specific embodiments of the present invention, the binder is selected from at least one of boehmite-acid mixed slurry, alumina sol, silica sol and sodium silicate-acid mixed slurry.

[0056] According to some specific embodiments of the present invention, the mass concentration of boehmite in the boehmite-acid mixed slurry is 20-55 wt%.

[0057] According to some specific embodiments of the present invention, the mass concentration of sodium silicate in the sodium silicate-acid mixed slurry is 20-30 wt%.

[0058] According to some specific embodiments of the present invention, the aluminum oxide content in the aluminum sol is 10-40 wt%.

[0059] According to some specific embodiments of the present invention, the content of silicon oxide in the silica sol is 10-40 wt%.

[0060] According to some specific embodiments of the present invention, the acid is at least one selected from nitric acid, hydrochloric acid, citric acid, oxalic acid, or sulfuric acid.

[0061] According to some specific embodiments of the present invention, the pH of the adhesive is 3 to 5.

[0062] According to some specific embodiments of the present invention, the mass ratio of slurry A, slurry B and slurry C is 1:(0.7-1.4):(0.4-1.6).

[0063] According to some specific embodiments of the present invention, the calcination temperature is 500-700°C.

[0064] According to some specific embodiments of the present invention, the calcination temperature is 500-600°C.

[0065] According to some specific embodiments of the present invention, the roasting time is 3-10 hours.

[0066] According to some specific embodiments of the present invention, the roasting time is 3 to 5 hours.

[0067] According to some specific embodiments of the present invention, the drying temperature is 80–140°C.

[0068] According to some specific embodiments of the present invention, the drying temperature is 80-100°C.

[0069] Furthermore, the present invention also provides the application of the aforementioned regenerative catalyst in the catalytic cracking of light hydrocarbons to produce low-carbon olefins.

[0070] According to some specific embodiments of the present invention, the low-carbon olefin is selected from at least one of ethylene, propylene and butene.

[0071] According to some specific embodiments of the present invention, the light hydrocarbon is naphtha.

[0072] According to some specific embodiments of the present invention, the naphtha is a typical straight-run naphtha.

[0073] According to some specific embodiments of the present invention, the content of saturated hydrocarbons in the typical straight-run naphtha is not less than 65 wt%.

[0074] According to some specific embodiments of the present invention, the reactor for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is a riser reactor.

[0075] According to some specific embodiments of the present invention, the reaction temperature for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is 600–700°C.

[0076] According to some specific embodiments of the present invention, the reaction time for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is 0.3-8 s.

[0077] According to some specific embodiments of the present invention, the carrier gas for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is water vapor.

[0078] According to some specific embodiments of the present invention, the weight hourly space velocity (WHSV) for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is 0.1-30 h⁻¹. -1 .

[0079] According to some specific embodiments of the present invention, the catalyst-to-oil ratio (weight ratio of catalyst to feedstock oil) for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is 10-24.

[0080] According to some specific embodiments of the present invention, the water-to-oil ratio (weight ratio of steam to feedstock oil) for the catalytic cracking of light hydrocarbons to produce low-carbon olefins is 0.5 to 10.

[0081] According to some specific embodiments of the present invention, the pressure for catalytic cracking of light hydrocarbons to produce low-carbon olefins is atmospheric pressure.

[0082] In summary, this invention provides a regenerative catalyst, its preparation, and its application. The catalyst of this invention has the following advantages:

[0083] (1) Improve yield and selectivity. During the reaction, catalysts containing materials with high specific heat capacity and high thermal conductivity can effectively reduce the temperature difference between the catalyst axis or radial direction during the reaction, ensure the uniform distribution of heat inside the reactor, avoid unnecessary side reactions promoted by excessively high temperature in the high-temperature section, and avoid loss of low carbon olefin yield, thereby improving the stability and consistency of the reaction process.

[0084] (2) Optimize heat utilization. By tightly loading the heat storage material and molecular sieve, heat transfer is enhanced, energy loss is significantly reduced, and heat utilization efficiency is greatly improved, thereby optimizing the entire energy cycle. Under the same energy consumption, the yield and selectivity of low-carbon olefins in the catalytic cracking reaction are improved, the output of high value-added products is increased, and energy waste is effectively reduced.

[0085] In summary, this invention, through catalyst design and optimized heat management, not only improves product yield and selectivity but also optimizes energy utilization, providing strong support for the efficient and stable operation of catalytic cracking, while promoting energy conservation and environmental protection. Detailed Implementation

[0086] The following detailed embodiments illustrate the implementation process and beneficial effects of the present invention, aiming to help readers better understand the essence and characteristics of the present invention, and are not intended to limit the scope of implementation of this case.

[0087] Example 1

[0088] Under stirring conditions, 900g of kaolin, 100g of boehmite-hydrochloric acid solution (pH 3), and 1800g of deionized water were uniformly mixed to obtain slurry A. 1500g of REY molecular sieve, 300g of kaolin, 100g of alumina sol (alumina content 10wt%), and 2000g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 100g of kaolin, 400g of magnesium oxide, 100g of alumina sol, and 600g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and calcined at 500℃ for 5 hours. Then, deionized water was added, stirred evenly, washed at 80℃ for 20 minutes, and filtered to obtain catalyst FCC-1.

[0089] Example 2

[0090] Under stirring conditions, 900g of sepiolite, 100g of boehmite-nitric acid solution (pH 5), and 1800g of deionized water were uniformly mixed to obtain slurry A. 300g of USY molecular sieve, 300g of sepiolite, 400g of alumina sol (alumina content 40wt%), and 1200g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 200g of sepiolite, 550g of silicon carbide, 250g of alumina sol, and 1600g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and calcined at 700℃ for 6 hours. Then, deionized water was added, stirred evenly, washed at 100℃ for 20 minutes, and filtered to obtain catalyst FCC-2.

[0091] Example 3

[0092] Under stirring conditions, 800g of attapulgite, 100g of boehmite-citric acid solution (pH 4), and 1600g of deionized water were uniformly mixed to obtain slurry A. 500g of ZSM-5 molecular sieve, 100g of attapulgite, 100g of alumina sol (alumina content 40wt%), and 1200g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 100g of attapulgite, 1200g of aluminum nitride, 100g of alumina sol, and 2400g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and calcined at 550℃ for 8 hours. Then, deionized water was added, stirred evenly, washed at 140℃ for 20 minutes, and filtered to obtain catalyst FCC-3.

[0093] Example 4

[0094] Under stirring conditions, 800g of palygorskite, 200g of sodium silicate-oxalic acid solution (pH 5), and 1600g of deionized water were uniformly mixed to obtain slurry A. 700g of HY molecular sieve, 100g of palygorskite, 100g of silica sol (40wt% silica content), and 1600g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 100g of palygorskite, 800g of silicon nitride, 100g of silica sol, and 1800g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and calcined at 600℃ for 10 hours. Then, deionized water was added, stirred evenly, washed at 100℃ for 20 minutes, and filtered to obtain catalyst FCC-4.

[0095] Example 5

[0096] Under stirring conditions, 850g of montmorillonite, 150g of sodium silicate-sulfuric acid solution (pH 4), and 1500g of deionized water were uniformly mixed to obtain slurry A. 500g of REUSY molecular sieve, 300g of diatomaceous earth, 200g of silica sol (10wt% silica content), and 1600g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 650g of montmorillonite, 300g of boron nitride, 50g of silica sol, and 1900g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and calcined at 600℃ for 3 hours. Then, deionized water was added, stirred evenly, washed at 120℃ for 20 minutes, and filtered to obtain catalyst FCC-5.

[0097] Comparative Example 1

[0098] Under stirring conditions, 800g of kaolin, 200g of sodium silicate-oxalic acid solution (pH 5), and 1600g of deionized water were uniformly mixed to obtain slurry A. 700g of HY molecular sieve, 100g of kaolin, 100g of silica sol (40wt% silica content), and 1600g of deionized water were mixed and stirred for 1 hour to obtain slurry B. 900g of kaolin, 100g of silica sol, and 1800g of deionized water were mixed and stirred for 1 hour to obtain slurry C. Slurries A, B, and C were mixed, homogenized, spray-molded, and then calcined at 600℃ for 10 hours. Deionized water was then added, stirred evenly, washed at 100℃ for 20 minutes, and filtered to obtain the comparative catalyst FCC-6.

[0099] See Table 1, which shows the physical properties of the naphtha used in the embodiments and comparative examples of the present invention.

[0100] Table 1

[0101] Naphtha property parameters Data Density (20°C), g / cm 3 ]] 0.7412 Group composition, w% n-alkanes 36.42 iso-alkanes 30.01 olefins 0.54 naphthenes 23.45 aromatics 9.58 Distillation range, °C IBP 45 10％ 89 30％ 112 50％ 121 70％ 130 90％ 154 95％ 161

[0102] See Table 2, which shows the catalyst evaluation results for the embodiments and comparative examples of the present invention.

[0103] Table 2

[0104]

[0105]

[0106] As shown in Table 2, the catalysts obtained in Examples 1-5 of this invention can achieve a conversion rate of over 75% and a triene yield of over 47% in the naphtha catalytic cracking reaction under various reaction conditions. Combined with the comparative examples, this invention uses a heat-storing material to synthesize a novel catalyst matrix, resulting in a high conversion rate and low-carbon olefin yield during the reaction. Table 2 also shows that the addition of the heat-storing material to the matrix significantly optimizes the temperature range of the catalyst bed. This indicates that the addition of the heat-storing material ensures better heat distribution throughout the catalyst bed, allowing for rapid heat release during the reaction. This avoids the adverse effects of excessive temperature gradients on catalyst stability, ensuring the catalyst maintains high activity and selectivity within its optimal operating temperature range and suppressing side reactions.

[0107] See Table 3, which shows the temperatures at different locations in the reactor and regenerator beds during the naphtha catalytic cracking to produce low-carbon olefins reaction with and without the addition of heat storage materials.

[0108] Table 3

[0109]

[0110]

[0111] Due to the lack of heat storage material, the temperature difference between the reactor and the regenerator is significant. In the comparison between Example 3 and Comparative Example 1, the catalyst using heat storage material had a temperature difference of 16°C between the inlet and outlet (upper part of the bed) while maintaining a central temperature of 660°C; whereas the catalyst in Comparative Example 1 had a temperature difference of 42°C between the inlet and outlet. This increased temperature difference accelerates the side reaction rate, reduces catalyst activity and selectivity, and decreases the yield of low-carbon olefins. Furthermore, light hydrocarbon feedstocks such as naphtha produce less carbon during the reaction. To ensure the catalyst reaches the optimal reaction temperature at the outlet during regeneration, pulverized coal or oil needs to be injected into the regenerator to provide additional heat. Based on the comparison between Example 3 and Comparative Example 1, the temperature difference in the regeneration section of the catalyst using heat storage material is 10°C, while the temperature difference in the reheat section of Comparative Example 1 is 36°C. This means that Comparative Example 1 requires 3.5 times more pulverized coal or oil to be burned during regeneration, resulting in higher CO2 emissions and increased costs.

Claims

1. The application of a regenerative catalyst in the catalytic cracking of light hydrocarbons to produce low-carbon olefins, wherein, Based on a dry basis of 100%, the catalyst contains at least the following components by weight percentage: 10%-50% molecular sieve, 10%-40% heat storage material, and 40%-80% support. The heat storage material has a thermal conductivity of 20-500 W / m·K and a specific heat capacity of 600-1200 J / kg·K. The support is SiO2 and / or Al2O3. The heat storage material is selected from at least one of magnesium oxide, silicon carbide, aluminum nitride, silicon nitride, and boron nitride. The molecular sieve is selected from at least one of Y-type molecular sieve, β-type molecular sieve, and MFI molecular sieve.

2. The application according to claim 1, wherein, The catalyst contains at least the following components by weight percentage: 15%-30% molecular sieve, 25%-40% heat storage material, and 40%-60% carrier.

3. The application according to claim 1, wherein, The particle size of the heat storage material is 100-200 mesh.

4. The application according to any one of claims 1 to 3, wherein, The preparation method of the regenerative catalyst includes the following steps: In the step of preparing slurry A by mixing clay, binder and water, the mass ratio of clay to binder is (0.5~0.9):(0.1~0.2), and the water is 1-2 times the total solid mass of this step; In the step of mixing molecular sieve, clay, binder and water to obtain slurry B, the mass ratio of molecular sieve, clay and binder is (0.3~1.5): (0.1~0.3): (0.1~0.4), and the water is 1-2 times the total solid mass of this step; In the step of mixing heat storage material, clay, binder and water to obtain slurry C, the mass ratio of heat storage material, clay and binder is (0.3~1.2): (0.1~0.65): (0.05~0.25), and the water is 1-2 times the total solid mass of this step; The catalyst is obtained by mixing slurry A, slurry B and slurry C in a mass ratio of 1:(0.7-1.4):(0.4-1.6), spray drying and then calcining.

5. The application according to claim 4, wherein, The binder is selected from at least one of the following: pseudo-boehmite-acid mixed slurry, alumina sol, silica sol, and sodium silicate-acid mixed slurry.

6. The application according to claim 5, wherein, The pseudoboehmite accounts for 20-55 wt% in the slurry.

7. The application according to claim 5, wherein, Sodium silicate accounts for 20-30 wt% in the slurry.

8. The application according to claim 5, wherein, The aluminum sol contains 10-40 wt% aluminum oxide.

9. The application according to claim 5, wherein, The silica sol contains 10-40 wt% silica.

10. The application according to claim 4, wherein, The clay is selected from at least one of kaolin, sepiolite, attapulgite, palygorskite, montmorillonite, and diatomite.

11. The application according to claim 10, wherein, The roasting temperature is 500-700℃.

12. The application according to claim 11, wherein, The roasting time is 3-10 hours.

13. The application according to claim 1, wherein, The low-carbon olefin is selected from at least one of ethylene, propylene, and butene.

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