Heat storage type catalyst as well as preparation and application thereof

Abstract

The invention provides a heat storage type catalyst and preparation and application thereof.The catalyst at least comprises, by weight, 10%-50% of a molecular sieve, 10%-40% of a heat storage material and 40%-80% of a carrier, the heat conductivity coefficient of the heat storage material is 20-500 W / m.K, and the specific heat capacity of the heat storage material is 600-1200 J / kg.K. Through catalyst design and heat management optimization, the yield and selectivity of the product are improved, energy utilization is optimized, powerful support is provided for efficient and stable operation of catalytic cracking, and meanwhile energy conservation and environment protection are promoted.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a heat storage catalyst and its preparation and application. Background Art

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

[0003] In order 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 / carrier, and the carrier is selected from heat storage materials such as silicon oxide, aluminum oxide, activated carbon, and silicon carbide, which can make the catalyst release heat in the reduction stage and air regeneration stage, making the bed temperature distribution more uniform, extending the catalyst life, and reducing the energy consumption of the device. However, the catalyst activity is low, and only the heat storage capacity is considered, not the thermal conductivity, which may still cause the problem of uneven heat in the catalyst.

[0004] Patent CN110479362A discloses a catalyst for producing more 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 them, materials such as kaolin and montmorillonite have low thermal conductivity. During the reaction process, the catalyst carrier is not easy to quickly transfer heat to various parts of the reactor, and it is difficult to achieve uniform heat distribution.

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

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

[0007] The 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 internal high-density heat; during the regeneration stage, it can enhance heat transfer at close range, store more heat, and reduce the need for external heat supplement, 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 thermal storage catalyst.

[0009] Another object of the present invention is to provide a use of the thermal storage catalyst.

[0010] To achieve the above-mentioned purpose, on the one hand, the present invention provides a heat storage catalyst, wherein, based on the dry basis of the catalyst as 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, and the thermal conductivity of the heat storage material is 20-500W / m·K, and the specific heat capacity is 600-1200J / kg·K.

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

[0012] According to some specific embodiments of the present invention, the carrier is SiO 2 and / or Al 2 O 3 .

[0013] According to some specific embodiments of the present invention, wherein SiO 2 Derived from binder (silica sol, sodium silicate-acid mixed slurry) and / or clay (kaolin, montmorillonite, etc.); Al 2 O 3 Derived from binder (alumina sol, boehmite-acid mixed 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 thermal storage material is 100-200 meshes.

[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 thermal conductivity of the magnesium oxide is 40-60 W / m·K, and the specific heat capacity is 1000 J / kg·K.

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

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

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

[0021] According to some specific embodiments of the present invention, the thermal conductivity of aluminum nitride is 140-180 W / m·K, and the specific heat capacity is 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 m 2 / g, specific pore volume 0.05~0.2cm 3 / g.

[0023] According to some specific embodiments of the present invention, the thermal conductivity of silicon nitride is 20-30 W / m·K, and the specific heat capacity is 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 m 2 / g, specific pore volume 0.1~0.4cm 3 / g.

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

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

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

[0028] According to some specific embodiments of the present invention, the molecular sieve is at least one selected from 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 at least one selected from 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 crystal size of the molecular sieve is 0.2-10 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 thermal storage catalyst, wherein the method comprises the following steps:

[0033] A step of mixing clay, a binder and water to prepare a slurry A, wherein the mass ratio of clay to the binder is (0.5-0.9):(0.1-0.2), and water is 1-2 times the total solid mass of this step;

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

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

[0036] The step of uniformly 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 to obtain the catalyst.

[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 thermal 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, rectorite, montmorillonite and diatomaceous earth.

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

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

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

[0046] According to some specific embodiments of the present invention, the sepiolite has a specific surface area of ​​200 to 400 m 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 to 200 m 2 / g, specific pore volume 0.2~0.4cm 3 / g.

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

[0050] According to some specific embodiments of the present invention, the rectorite has a specific surface area of ​​250 to 400 m 2 / g, specific pore volume 0.4~0.6cm 3 / g.

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

[0052] According to some specific embodiments of the present invention, the montmorillonite has a specific surface area of ​​200 to 800 m 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 0.1-0.2 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 to 30 m 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 pseudo-boehmite-acid mixed slurry, aluminum sol, silica sol and sodium silicate-acid mixed slurry.

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

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

[0058] According to some specific embodiments of the present invention, the content of aluminum oxide 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 of 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 binder is 3-5.

[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 calcination time is 3-10 hours.

[0066] According to some specific embodiments of the present invention, the calcination 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] In another aspect, the present invention also provides the use of the heat storage 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 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 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 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 of catalytic cracking of light hydrocarbons to produce low-carbon olefins is 0.3-8s.

[0077] According to some specific embodiments of the present invention, the carrier gas for 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 of catalytic cracking of light hydrocarbons to produce light olefins is 0.1-30h -1 .

[0079] According to some specific embodiments of the present invention, the catalyst-to-oil ratio (the weight ratio of catalyst to feedstock oil) of 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 water vapor to feedstock oil) of catalytic cracking of light hydrocarbons to produce low-carbon olefins is 0.5-10.

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

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

[0083] (1) Improve yield and selectivity. During the reaction process, catalysts containing materials with high specific heat capacity and high thermal conductivity can effectively reduce the axial or radial temperature difference of the catalyst during the reaction, ensure the uniform distribution of heat inside the reactor, avoid unnecessary side reactions caused by excessive temperature in the high temperature section, and lead to the loss of light olefin yield, thereby improving the stability and consistency of the reaction process.

[0084] (2) Optimize heat utilization. By closely loading the thermal storage material and molecular sieve, heat transfer is enhanced, energy loss is significantly reduced, and the 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, the present invention optimizes heat management through catalyst design, which not only improves the yield and selectivity of the product, but also optimizes energy utilization, provides strong support for the efficient and stable operation of catalytic cracking, and promotes energy conservation and environmental protection. DETAILED DESCRIPTION

[0086] The implementation process of the present invention and the beneficial effects produced are described in detail below through specific embodiments, which is intended to help readers better understand the essence and characteristics of the present invention, and is not intended to limit the scope of implementation of the present invention.

[0087] Example 1

[0088] Under stirring conditions, 900g of kaolin, 100g of pseudo-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 aluminum sol (alumina content is 10wt%) and 2000g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 100g of kaolin, 400g of magnesium oxide, 100g of aluminum sol and 600g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 500℃ for 5h. Then deionized water was added, stirred evenly, washed at 80℃ for 20min, and filtered to obtain catalyst FCC-1.

[0089] Example 2

[0090] Under stirring conditions, 900g of sepiolite, 100g of pseudo-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 aluminum sol (alumina content is 40wt%) and 1200g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 200g of sepiolite, 550g of silicon carbide, 250g of aluminum sol and 1600g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 700℃ for 6h. Then deionized water was added, stirred evenly, washed at 100℃ for 20min, and filtered to obtain catalyst FCC-2.

[0091] Example 3

[0092] Under stirring conditions, 800g of attapulgite, 100g of pseudo-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 aluminum sol (alumina content is 40wt%) and 1200g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 100g of attapulgite, 1200g of aluminum nitride, 100g of aluminum sol and 2400g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 550°C for 8h. Then deionized water was added, stirred evenly, washed at 140°C for 20min, and filtered to obtain catalyst FCC-3.

[0093] Example 4

[0094] Under stirring conditions, 800g of rectorite, 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 rectorite, 100g of silica sol (the content of silicon oxide is 40wt%) and 1600g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 100g of rectorite, 800g of silicon nitride, 100g of silica sol and 1800g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 600℃ for 10h. Then deionized water was added, stirred evenly, washed at 100℃ for 20min, 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 (the content of silicon oxide is 10wt%) and 1600g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 650g of montmorillonite, 300g of boron nitride, 50g of silica sol and 1900g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 600℃ for 3h. Then deionized water was added, stirred evenly, washed at 120℃ for 20min, 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 (the content of silicon oxide is 40wt%) and 1600g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry B. 900g of kaolin, 100g of silica sol and 1800g of deionized water were mixed and slurried, and stirred for 1h to obtain slurry C. Slurries A, B and C were mixed, and the slurry was homogenized, sprayed and calcined at 600℃ for 10h. Then deionized water was added, stirred evenly, washed at 100℃ for 20min, and filtered to obtain comparative catalyst FCC-6.

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

[0100] Table 1

[0101] Naphtha properties parameters data <![CDATA[Density (20 °C), g / cm 3 > 0.7412 Group composition, w% Normal alkanes 36.42 Isoalkanes 30.01 Olefins 0.54 Cycloalkanes 23.45 Aromatics 9.58 Distillation range,℃ IBP 45 10％ 89 30％ 112 50％ 121 70％ 130 90％ 154 95％ 161

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

[0103] Table 2

[0104]

[0105]

[0106] As can be seen from Table 2, the catalysts obtained in Examples 1-5 of the present invention can obtain a conversion rate of more than 75% and a triene yield of more than 47% in the process of naphtha catalytic cracking reaction under various reaction conditions; combined with the comparative example, the present invention adopts heat storage materials to synthesize a new catalyst matrix, so that during the reaction process, it has a higher conversion rate and a lower carbon olefin yield. As can be seen from Table 2, after adding the heat storage material to the matrix, the temperature variation range of the catalyst bed is significantly optimized, indicating that the addition of the heat storage material enables the catalytic cracking reaction to obtain a better heat distribution in the entire catalyst bed, and can quickly release heat during the reaction process, which can avoid the adverse effect of excessive bed temperature gradient on the catalyst stability during the reaction process, ensure that the catalyst maintains a high activity and selectivity within the optimal operating temperature, and inhibit the occurrence of side reactions.

[0107] See Table 3, which shows the temperatures at different positions of the reactor and regenerator bed in the naphtha catalytic cracking reaction to produce light olefins when the heat storage material is added and when the heat storage material is not added.

[0108] Table 3

[0109]

[0110]

[0111] Due to the lack of support from heat storage materials, the temperature difference between the reactor and the regenerator is large. In the comparison between Example 3 and Comparative Example 1, when the catalyst using heat storage materials maintains the middle temperature at 660°C, the temperature difference between the bed inlet and outlet (upper part of the bed) is 16°C; while the temperature difference between the bed inlet and outlet of the catalyst in Comparative Example 1 is 42°C. This increase in temperature difference will increase the reaction rate of side reactions, reduce catalyst activity and selectivity, and reduce the yield of low-carbon olefins. In addition, light hydrocarbon feedstocks such as naphtha have less carbon deposits during the reaction process. In order for the regenerated catalyst to reach the optimal reaction temperature at the outlet, it is necessary to spray coal powder or oil products into the regenerator to provide additional heat. According to the comparison between Example 3 and Comparative Example 1, the temperature difference in the regeneration section of the catalyst using heat storage materials is 10°C, while the temperature difference in the regeneration section of Comparative Example 1 is 36°C. This requires Comparative Example 1 to burn 3.5 times more coal powder or oil products during the regeneration process, which will result in more CO emissions. 2 , and increase cost investment.

Claims

1. A thermal storage catalyst, wherein: Taking the dry basis of the catalyst as 100%, the catalyst contains at least the following components in weight percentage: 10%-50% molecular sieve, 10%-40% heat storage material, and 40%-80% carrier. The thermal conductivity of the heat storage material is 20-500W / m·K, and the specific heat capacity is 600-1200J / kg·K. Preferably, the catalyst contains at least the following components in weight percentage: 15%-30% molecular sieve, 25%-40% heat storage material, and 40-60% carrier.

2. The catalyst according to claim 1, wherein the carrier is SiO2 and / or Al2O3.

3. The catalyst according to any one of claims 1 to 2, wherein The particle size of the thermal storage material is 100-200 meshes.

4. The catalyst according to any one of claims 1 to 3, wherein The heat storage material is selected from at least one of magnesium oxide, silicon carbide, aluminum nitride, silicon nitride and boron nitride.

5. The catalyst according to any one of claims 1 to 4, wherein The molecular sieve is at least one of a Y-type molecular sieve, a β-type molecular sieve and an MFI molecular sieve.

6. The method for preparing a thermal storage catalyst according to any one of claims 1 to 5, wherein: The method comprises the following steps: A step of mixing clay, a binder and water to prepare slurry A, wherein the mass ratio of clay to binder is (0.5-0.9):(0.1-0.2), and water is 1-2 times the total solid mass of this step; A step of mixing molecular sieve, clay, binder and water to obtain slurry B, wherein the mass ratio of molecular sieve, clay and binder is (0.3-1.5):(0.1-0.3):(0.1-0.4), and water is 1-2 times the total solid mass of this step; A step of mixing a thermal storage material, clay, a binder and water to obtain a slurry C, wherein the mass ratio of the thermal storage material, clay and the binder is (0.3-1.2):(0.1-0.65):(0.05-0.25), and water is 1-2 times the total solid mass of this step; The step of uniformly 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 to obtain the catalyst.

7. The preparation method according to claim 6, wherein: The binder is selected from at least one of pseudo-boehmite-acid mixed slurry (preferably the pseudo-boehmite accounts for 20-55wt% in the slurry), aluminum sol, silica sol and sodium silicate-acid mixed slurry (preferably the sodium silicate accounts for 20-30wt% in the slurry) (preferably the aluminum sol has a content of aluminum oxide of 10-40wt%; the silica sol has a content of silicon oxide of 10-40wt%).

8. The preparation method according to claim 6 or 7, wherein: The clay is selected from at least one of kaolin, sepiolite, attapulgite, rectorite, montmorillonite and diatomaceous earth.

9. The preparation method according to claim 8, wherein: The calcination temperature is 500-700° C. (preferably the calcination time is 3-10 h).

10. Use of the heat storage catalyst according to any one of claims 1 to 5 in catalytic cracking of light hydrocarbons to produce light olefins (preferably, the light olefins are selected from at least one of ethylene, propylene and butene).

Images