Catalyst composition for catalytic conversion of waste plastic oil, preparation method and application thereof, and method for producing low-carbon olefin by catalytic conversion of waste plastic oil

Abstract

The invention relates to the technical field of catalysts for waste plastic oil, and discloses a catalyst composition for catalytic conversion of waste plastic oil, a preparation method and application of the catalyst composition, and a method for producing low-carbon olefin through catalytic conversion of waste plastic oil. The catalyst composition comprises a catalyst A and a catalyst B. Based on the total weight of the catalyst composition, the content of the catalyst A is 5-60%, and the content of the catalyst B is 40-95%. On the basis of the dry base weight of the catalyst A, the catalyst A contains the following components: 30-70% of mesopore and macropore pseudo-boehmite, 10-40% of an aluminum-based binder and 5-60% of first clay; on the basis of the dry base weight of the catalyst B, the catalyst B contains the following components: 30-60% of a molecular sieve, 10-40% of a silicon-based binder and 5-60% of second clay. The catalyst composition not only can capture and contain silicon impurities in waste plastic oil, but also can improve the yield of low-carbon olefins.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalysts for waste plastic oil, in particular to a catalyst composition for catalytic conversion of waste plastic oil, a preparation method and application thereof, and a method for producing low-carbon olefins through catalytic conversion of waste plastic oil. BACKGROUND

[0002] The conventional disposal methods of waste plastics include landfilling, incineration and recycling. Landfilling will occupy a large amount of land resources for a long time, and toxic and harmful substances in plastics will leach into the land and spread. Incineration will produce toxic and harmful gases, causing secondary pollution of the environment. Recycling can be divided into energy recovery, mechanical recycling and chemical recycling. Chemical recycling of waste plastics is considered as a sustainable waste plastic recycling method, which not only solves the problem of environmental pollution, but also saves energy consumption.

[0003] At present, the waste plastic cracking method is a relatively mature chemical recycling method of waste plastics, that is, through thermal cracking, complex plastic macromolecules are converted into small molecule products (usually gas or liquid) mainly composed of hydrocarbons, which can be further produced into petrochemical products.

[0004] Patent application CN114507539A discloses a method and system for preparing low-carbon olefins from waste plastics. The waste plastics are sequentially treated in a waste plastic dissolution and dechlorination unit and a waste plastic hot dissolution and impurity removal unit to obtain a de-impurity plastic-containing solution. The obtained de-impurity plastic-containing solution is introduced into a catalytic cracking unit, and the catalytic cracking catalyst is contacted with the optional catalytic cracking raw material to react. The reaction effluent is separated to obtain a catalytic cracking product including low-carbon olefins. The present application prepares olefin monomers from waste plastics, which realizes the closed cycle of waste plastics and truly realizes the recycling of plastics.(Sinopec)

[0005] Patent application CN113398982A discloses a catalyst for preparing low-carbon olefins from waste plastics by catalytic cracking, which comprises a silicon-aluminum matrix and a molecular sieve. The silicon-aluminum matrix comprises a silicon-containing substance and an aluminum-containing substance, and the molecular sieve comprises ZSM 5 molecular sieve or / and ZSM11 molecular sieve. The catalyst is applied to the preparation of low-carbon olefins from waste plastics by catalytic cracking, which improves the yield of low-carbon olefins and improves the quality of gasoline. The waste plastics in the patent are composed of PE:PP:PS=5:3:2.(Huicheng)

[0006] Patent application CN110563011A discloses a desiliconizing agent for preparing alumina and a preparation method thereof. The desiliconizing agent is composed of red mud, desiliconizing slag, fly ash and lime. The method is to sinter the red mud and the desiliconizing slag respectively, and then grind them into powder; mix the prepared red mud powder and desiliconizing slag powder with fly ash and lime uniformly to obtain the desiliconizing agent.(Southwest Energy and Mine Group Co., Ltd.)

[0007] However, in reality, waste plastics are of various types and from various sources, and it is difficult to separate the various components in mixed waste plastics by simple and low-cost means due to the similar apparent physical properties of various common plastics, which causes problems such as unstable composition and high impurity content of waste plastic oil obtained by cracking of waste plastics.

[0008] It is believed by SINOPEC Research Institute of Petroleum Processing (SRI) that the hydrocarbon composition of waste plastic oil is similar to that of petroleum distillate, and it is theoretically feasible to use waste plastic oil as a raw material for catalytic cracking process, but the high content of silicon and chlorine in waste plastic oil will have some impact on the catalytic cracking process. The silicon species in waste plastic oil mainly come from the thermal cracking products of silicon-containing additives in plastics, and usually exist in the form of alkyl cyclosiloxane, mainly octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane, with Si content of 10-103 μg / g. During the subsequent processing of waste plastic oil, silicon species mainly deposit on the surface of the catalyst, affecting the activity of the catalyst. (Li Mingfeng, Chemical Recycling and Chemical Recycling Technology of Waste Plastics in SINOPEC, China Plastics, 2021)

[0009] Therefore, in the technical route of catalytic conversion of waste plastic oil to produce low-carbon olefins or oil products, the influence of impurity silicon in waste plastic oil cannot be ignored. Measures to treat impurity silicon in waste plastic oil include desiliconization and silicon tolerance. SRI (CN113862018A) has developed a new technology for removing organic silicon by dissolving waste plastics in special oil, which can not only remove silicon, but also reduce the viscosity of waste plastics and improve the heat transfer efficiency; however, in the process of catalytic conversion of waste plastic oil to produce low-carbon olefins, it is difficult to simultaneously have high silicon tolerance and high target product yield. SUMMARY

[0010] The purpose of the present application is to overcome the problems existing in the prior art, and to provide a catalyst composition for catalytic conversion of waste plastic oil, a preparation method and application thereof, and a method for producing low-carbon olefins by catalytic conversion of waste plastic oil, which can not only capture and accommodate silicon impurities in waste plastic oil, but also improve the yield of low-carbon olefins generated by conversion of waste plastic oil.

[0011] To achieve the above-mentioned purpose, the first aspect of the present application provides a catalyst composition for catalytic conversion of waste plastic oil, wherein the catalyst composition comprises catalyst A and catalyst B, and the content of the catalyst A is 5-60% and the content of the catalyst B is 40-95% based on the total weight of the catalyst composition.

[0012] The catalyst A contains the following components based on the dry base weight of the catalyst A: 30-70% of mesoporous pseudoboehmite, 10-40% of an aluminum-based binder and 5-60% of a first clay; the total pore volume of the catalyst A is not less than 0.3 mL / g; the pore volume of the pores of 10-100 nm in the catalyst A accounts for more than 65% of the total pore volume;

[0013] The catalyst B contains the following components based on the dry base weight of the catalyst B: 30-60% of a molecular sieve, 10-40% of a silicon-based binder and 5-60% of a second clay.

[0014] The second aspect of the present application provides a preparation method of a catalyst composition for catalytic conversion of waste plastic oil, wherein the preparation method comprises the following steps:

[0015] (1) mixing mesoporous pseudoboehmite, an aluminum-based binder, a first clay and water to obtain a first slurry, and then performing first dry molding and first calcination on the first slurry to obtain a catalyst A;

[0016] (2) mixing a molecular sieve, a silicon-based binder, a second clay and water to obtain a second slurry, and then performing second dry molding and second calcination on the second slurry to obtain a catalyst B;

[0017] (3) mixing the catalyst A and the catalyst B.

[0018] The third aspect of the present application provides an application of the catalyst composition for catalytic conversion of waste plastic oil in the first aspect in a catalytic conversion reaction of waste plastic oil.

[0019] The fourth aspect of the present application provides a method for producing low-carbon olefins by catalytic conversion of waste plastic oil, wherein the method comprises the following steps: contacting waste plastic oil with a catalyst, and the catalyst is the catalyst composition for catalytic conversion of waste plastic oil in the first aspect; the waste plastic oil contains silicon and chlorine, the content of silicon is 1-1000 mg / kg, and the content of chlorine is 1-1000 mg / kg.

[0020] The application provides a catalyst composition for catalytic conversion of waste plastic oil, the catalyst A contains mesoporous pseudoboehmite with mesoporous structure as one of raw materials, which provides abundant mesoporous structure for the catalyst A, meanwhile, the aluminum-based binder and the first clay both contain high content of alumina, which cooperates with the mesoporous pseudoboehmite to be an aluminum-rich mesoporous catalyst, which can efficiently capture and accommodate organic silicon species in the waste plastic oil, reduce the influence of the silicon species on the performance of the catalyst B, meanwhile, the organic silicon species and the aluminum species of the catalyst A can react to generate silicon-aluminum components with acidic function in the catalytic conversion process, so that the pre-cracking capacity of the hydrocarbon components of the waste plastic oil is improved; the catalyst B contains high content of silicon oxide in the molecular sieve, the silicon-based binder and the second clay, so that the catalyst B can be a silicon-rich molecular sieve catalyst, which can improve the yield of low-carbon olefins generated by catalytic conversion of the hydrocarbon components of the waste plastic oil; further, the catalyst B has a specific pore size ratio, which is beneficial to improve the diffusion efficiency of the hydrocarbon molecules and avoid secondary conversion of the low-carbon olefins; the catalyst A and the catalyst B are complementary to each other, which can capture and accommodate the silicon impurities in the waste plastic oil and improve the capacity of the waste plastic oil to generate low-carbon olefins.

[0021] The application provides a method for producing low-carbon olefins by catalytic conversion of waste plastic oil, which selects a catalyst composition containing the catalyst A and the catalyst B, so that the yield of the target product, the low-carbon olefins, is improved on the basis of accommodating silicon, and the catalytic conversion of the waste plastic oil is realized. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the application. The ranges and values are approximations that are intended to convey the scope of the application. The endpoints of the ranges and values are provided as a separate point for the convenience of the reader. The application is not limited to the precise values recited.

[0023] In the application, the specific surface area of the mesoporous pseudoboehmite and the catalyst A is measured by a low-temperature static nitrogen adsorption capacity method.

[0024] In the application, the total pore volume and the pore size ratio of the mesoporous pseudoboehmite, the catalyst A and the catalyst B are measured by a low-temperature static nitrogen adsorption capacity method.

[0025] The first aspect of the application provides a catalyst composition for catalytic conversion of waste plastic oil, wherein the catalyst composition contains the catalyst A and the catalyst B, the content of the catalyst A is 5-60% based on the total weight of the catalyst composition, and the content of the catalyst B is 40-95%.

[0026] The catalyst A contains the following components: 30-70% of mesoporous pseudoboehmite, 10-40% of an aluminum-based binder and 5-60% of a first clay, based on the dry base weight of the catalyst A; the total pore volume of the catalyst A is not less than 0.3 mL / g; the pore volume of the pores of 10-100 nm in the catalyst A accounts for more than 65% of the total pore volume;

[0027] The catalyst B contains the following components: 30-60% of molecular sieve, 10-40% of a silicon-based binder and 5-60% of a second clay, based on the dry base weight of the catalyst B.

[0028] The catalyst composition for catalytic conversion of waste plastic oil provided by the application contains mesoporous pseudoboehmite with mesoporous structure as one of the raw materials in the catalyst A, which provides abundant mesoporous structure for the catalyst A, and the aluminum-based binder and the first clay both contain high content of alumina, which cooperates with the mesoporous pseudoboehmite to serve as an aluminum-rich mesoporous catalyst, efficiently capturing and accommodating organic silicon species in the waste plastic oil, reducing the influence of silicon species on the performance of the catalyst B, and meanwhile, in the catalytic conversion process, the organic silicon species reacts with the aluminum species of the catalyst A to generate silicon-aluminum components with certain acidic function, improving the pre-cracking ability of the hydrocarbon components of the waste plastic oil; the catalyst B contains high content of silicon oxide in the molecular sieve, the silicon-based binder and the second clay, which serves as a silicon-rich molecular sieve catalyst, capable of improving the yield of low-carbon olefins generated by catalytic cracking of the hydrocarbon components of the waste plastic oil; the components of the catalyst A and the catalyst B complement each other, which can not only capture and accommodate silicon impurities in the waste plastic oil, but also improve the ability of the waste plastic oil to crack to generate low-carbon olefins, realizing the recycling of waste resources of waste plastic oil.

[0029] In the application, the content of each component in the catalyst composition is calculated according to the feeding amount.

[0030] In the application, the content of each component in the catalyst A and the catalyst B is calculated based on the dry base.

[0031] In the application, the content of each component in the catalyst A is calculated based on the dry base, which means that the dry base content of each component accounts for the weight percentage of the dry base content of the catalyst A, and the dry base weight of each component refers to the amount of the remaining part after calcination at 600 DEG C for 2h. In the application, it can be understood that the content of each component in the catalyst B is calculated in the same way as the content of each component in the catalyst A.

[0032] In the application, the content of each component in the catalyst A and the catalyst B is calculated according to the feeding amount.

[0033] In the present application, preferably, the content of catalyst A is 10-50% and the content of catalyst B is 50-90% based on the total weight of the catalyst composition. The advantage of using this preferred embodiment is that the two can better match each other to realize the catalytic conversion of waste plastic oil and improve the yield of low-carbon olefins.

[0034] In the present application, preferably, the total pore volume of the catalyst A is 0.35-0.5 mL / g. The advantage of using this preferred embodiment is that it is beneficial to improve the diffusion efficiency of macromolecules, realize the catalytic conversion of waste plastic oil, and improve the yield of low-carbon olefins.

[0035] In the present application, preferably, the pore volume of the pores of 10-100 nm of the catalyst A accounts for 70-95% of the total pore volume.

[0036] In the present application, preferably, the specific surface area of the catalyst A is 200-400 m 2 / g.

[0037] In the present application, preferably, the catalyst A is an aluminum-rich mesoporous catalyst. Preferably, the content of alumina in the catalyst A is 50-99%, preferably 70-99%, based on the total weight of the catalyst A. The advantage of using this preferred embodiment is that the catalyst A is an aluminum-rich macroporous matrix microsphere which contains a high content of alumina, can efficiently capture and accommodate organic silicon species in waste plastic oil, reduce the influence of silicon species on the performance of catalyst B, and at the same time, in the catalytic conversion process, the organic silicon species reacts with the aluminum species of catalyst A to generate silicon-aluminum components with certain acidic function, improving the pre-cracking ability of the hydrocarbon components of waste plastic oil.

[0038] In the present application, the content of alumina in catalyst A is measured by X-ray fluorescence spectroscopy.

[0039] In the present application, preferably, based on the dry weight of the catalyst A, the catalyst A contains the following components: 35-65% of mesoporous pseudoboehmite, 15-35% of aluminum-based binder, and 5-50% of first clay. The catalyst A is prepared by using mesoporous pseudoboehmite with mesoporous structure and aluminum-based binder and first clay. The catalyst A contains a high content of alumina while having abundant mesoporous structure, can efficiently capture and accommodate organic silicon species in waste plastic oil, reduce the influence of silicon species on the performance of catalyst B, and at the same time, in the catalytic conversion process, the organic silicon species reacts with the aluminum species of catalyst A to generate silicon-aluminum components with certain acidic function, improving the pre-cracking ability of the hydrocarbon components of waste plastic oil.

[0040] In the present application, the meso-macroporous pseudo-boehmite has a large total pore volume, which can improve the silicon capacity of the catalyst composition. Preferably, the total pore volume of the meso-macroporous pseudo-boehmite is not less than 0.5 mL / g, preferably 0.8-2.5 mL / g, and further preferably 0.8-1.2 mg / L.

[0041] In the present application, preferably, the pore volume of the pores of 10-100 nm in the meso-macroporous pseudo-boehmite accounts for more than 80% of the total pore volume, and preferably 85-98%.

[0042] In the present application, preferably, the specific surface area of the meso-macroporous pseudo-boehmite is 200-500 m 2 / g.

[0043] In the present application, the source of the meso-macroporous pseudo-boehmite is not particularly limited, and it can be prepared by a method conventionally defined in the art, such as aluminum salt neutralization method, carbonization method, etc., and preferably aluminum salt neutralization method.

[0044] According to a specific embodiment of the present application, the preparation method of the meso-macroporous pseudo-boehmite comprises the following steps:

[0045] a. mixing an aluminate solution with an alkaline solution to perform a neutralization reaction, to obtain a neutralization slurry;

[0046] b. adjusting the pH of the neutralization slurry;

[0047] c. aging the neutralization slurry after adjusting the pH;

[0048] d. filtering and washing the aging product to obtain a filter cake;

[0049] e. drying the filter cake.

[0050] In the present application, the type of the aluminate-containing solution is not particularly limited. Preferably, in step a, the aluminate solution is selected from at least one of aluminum sulfate solution, sodium metaaluminate solution, aluminum nitrate solution and aluminum trichloride solution, and further preferably aluminum sulfate solution.

[0051] In the present application, the concentration of the aluminate-containing solution is not particularly limited. Preferably, the concentration of the aluminate-containing solution is 40-150 g / L in terms of aluminum oxide.

[0052] In the present application, the type of the alkaline solution is not particularly limited, as long as it can perform a neutralization reaction with the aluminate solution. Preferably, the alkaline solution is selected from at least one of sodium hydroxide solution, sodium carbonate solution and sodium metaaluminate solution, and further preferably sodium metaaluminate solution.

[0053] In the present application, the concentration and amount of the basic solution are not particularly limited, as long as the solution can be mixed with the aluminate-containing solution to satisfy the pH of the neutralization reaction.

[0054] In the present application, the mode of the neutralization reaction is not particularly limited, for example, it can be continuous and parallel flow neutralization.

[0055] In the present application, the conditions of the neutralization reaction are not particularly limited. Preferably, the conditions of the neutralization reaction include: pH value of 8.5-9.5, temperature of 35-75℃, residence time of 5-30min.

[0056] In the present application, preferably, in step b, the pH of the neutralized slurry is adjusted to 10-10.5. The pH adjustment is achieved by adding a solution of an aluminum-free basic compound after the neutralization reaction, preferably the solution of the aluminum-free basic compound is selected from at least one of sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution and ammonia water, preferably sodium carbonate solution.

[0057] In the present application, the concentration and amount of the solution of the aluminum-free basic compound are not particularly limited, as long as the pH of the neutralization can be adjusted to 10-10.5, which can be adjusted by the person skilled in the art according to the specific needs.

[0058] In the present application, preferably, in step c, the conditions of the aging include: temperature of 45-70℃, time of 3-48h.

[0059] In the present application, the mode of the filtration in step d is not particularly limited, for example, conventional filtration and washing modes such as vacuum filtration, plate and frame filtration can be used, which can be adjusted by the person skilled in the art according to the actual needs.

[0060] In the present application, the mode of the drying in step e is not particularly limited, for example, flash drying, oven drying, spray drying and the like can be used.

[0061] In the present application, the conditions of the drying in step e are not particularly limited, which can be selected by the person skilled in the art according to the time requirements.

[0062] In the present application, the type of the aluminum-based binder is not particularly limited, and the aluminum-rich binder defined in the art can be applied to the present application. Preferably, the aluminum-based binder is selected from at least one of aluminum sol, acidified pseudo-boehmite and aluminum silicate sol, and further preferably aluminum sol.

[0063] In the present application, preferably, the pore volume of the pores of 5-50nm in the catalyst B accounts for more than 80%, preferably 85-95% of the total pore volume.

[0064] In the present application, preferably, the total pore volume of the catalyst B is 0.2-0.5mg / L.

[0065] In the present application, preferably, the catalyst B is a silicon-rich molecular sieve catalyst. Preferably, the content of silicon oxide in the catalyst B is 60-90%, preferably 70-90%, based on the total weight of the catalyst B. The catalyst B contains a high content of silicon, which as a silicon-rich molecular sieve catalyst, can improve the ability of catalytic conversion of waste plastic oil to produce low-carbon olefins.

[0066] In the present application, the content of silicon oxide in the catalyst B is measured by X-ray fluorescence spectroscopy.

[0067] In the present application, each component in the catalyst B is a silicon-rich component, which can improve the ability of catalytic conversion of waste plastic oil to produce low-carbon olefins. Preferably, the catalyst B contains the following components based on the dry weight of the catalyst B: 35-55% of molecular sieve, 15-35% of silicon-based binder and 10-50% of second clay.

[0068] In the present application, the type of molecular sieve is not particularly limited. Preferably, the molecular sieve is ZSM-5 molecular sieve and / or β type molecular sieve.

[0069] In the present application, the specific type of ZSM-5 molecular sieve is not particularly limited, for example, it can be modified or unmodified ZSM-5 molecular sieve, for example, it can be HZSM-5 and / or ZSM-5 containing a modified component.

[0070] In the present application, the type of modified component is not particularly limited. Preferably, the modified component is selected from at least one of rare earth elements, Fe, Zn, Cu, Mg, Zr, Ti, B and phosphorus. In the present application, the specific type of rare earth element is not particularly limited, for example, it can be La, Ce, Y, etc.

[0071] According to a preferred embodiment of the present application, the ZSM-5 molecular sieve is selected from at least one of HZSM-5, ZSM-5 containing phosphorus and / or iron, and ZSM-5 containing phosphorus and / or rare earth elements.

[0072] In the present application, the specific type of β molecular sieve is not particularly limited. Preferably, the β molecular sieve is selected from at least one of hydrogen type β molecular sieve, phosphorus modified β molecular sieve and metal modified β molecular sieve. In the present application, the type of metal in the metal modified β molecular sieve is not particularly limited, which can be selected by those skilled in the art according to actual needs.

[0073] In the present application, the source of the molecular sieve is not particularly limited, for example, it can be obtained by commercial purchase.

[0074] In the present application, the type of the silicon-based binder is not particularly limited, and the silicon-rich binder defined in the art can be applied to the present application. Preferably, the silicon-based binder is a silica sol and / or an aluminum silicate sol, and further preferably a silica sol.

[0075] In the present application, the type of the first clay and the second clay is not particularly limited. Preferably, the first clay and the second clay are each independently selected from at least one of kaolin, lectorite, diatomite, montmorillonite, bentonite and sepiolite.

[0076] In the present application, the source of the first clay and the second clay is not particularly limited, and can be obtained by commercial purchase, for example.

[0077] The second aspect of the present application provides a preparation method of the catalyst composition for catalytic conversion of waste plastic oil according to the first aspect, wherein the preparation method comprises the following steps:

[0078] (1) first mixing mesoporous-pseudoboehmite, an aluminum-based binder, the first clay with water to obtain a first slurry, and then first drying and shaping the first slurry and first calcining to obtain catalyst A;

[0079] (2) second mixing molecular sieve, a silicon-based binder, the second clay with water to obtain a second slurry, and then second drying and shaping the second slurry and second calcining to obtain catalyst B;

[0080] (3) third mixing catalyst A and catalyst B.

[0081] In the present application, the type, property and source of the mesoporous-pseudoboehmite, the aluminum-based binder and the first clay have been described in the first aspect, and will not be repeated here.

[0082] In the present application, the condition of the first mixing is selected in a wide range. Preferably, in step (1), the condition of the first mixing comprises: the time is 0.5-5h, preferably 1-4h.

[0083] In the present application, the amount of water is not particularly limited, and preferably only needs to meet the solid content requirement of the first slurry. Preferably, in step (1), the solid content of the first slurry is 15-45wt%, preferably 20-40wt%, and further preferably 30-48wt%.

[0084] In the present application, the first dry molding method is not particularly limited, for example, it can be spray dry molding. In the present application, the spray dry molding refers to the granulation molding and drying of the catalyst, and the spray dry molding is a technology known to those skilled in the art, which can be operated according to the actual needs by those skilled in the art. In the present application, the spray drying conditions are not particularly limited, and preferably, the spray drying conditions include: the spray tail gas temperature is 100-250℃.

[0085] In the present application, the first calcination condition has a wide selection range. Preferably, in step (1), the first calcination condition includes: the temperature is 350-800℃, and the time is 0.5-6h; further preferably, the first calcination condition includes: the temperature is 400-650℃, and the time is 1-4h.

[0086] In the present application, the calcination treatment method is known to those skilled in the art, and the present application does not make a special limitation, for example, the calcination treatment can be carried out in a muffle furnace.

[0087] In the present application, the types, properties and sources of the molecular sieve, the silicon-based binder and the second clay have been described in the first aspect, and will not be repeated here.

[0088] In the present application, the second mixing condition is not particularly limited. Preferably, in step (2), the second mixing condition includes: the time is 0.5-6h, preferably 1-4h.

[0089] In the present application, the amount of water is not particularly limited, and preferably, it only needs to meet the solid content requirement of the second slurry. Preferably, in step (2), the solid content of the second slurry is 15-45wt%, preferably 20-40wt%, and further preferably 30-40wt%.

[0090] In the present application, the addition sequence of the molecular sieve, the silicon-based binder and the second clay in step (2) is not particularly limited, and those skilled in the art can adjust it according to the actual needs. According to a specific embodiment of the present application, the step (2) includes:

[0091] (2-1) mixing the molecular sieve, the second clay and water to obtain a mixed slurry;

[0092] (2-2) mixing the silicon-based binder and the mixed slurry to obtain a second slurry, and then carrying out second dry molding and second calcination on the second slurry.

[0093] In the present application, the conditions of the third mixing and the fourth mixing are not particularly limited, as long as the total mixing time of the third mixing and the fourth mixing meets the time of the second mixing. Preferably, the conditions of the third mixing include that the time is 0.5-5h. Preferably, the conditions of the fourth mixing include that the time is 10-60min.

[0094] In the present application, the mode and the conditions of the second dry molding are not particularly limited, which can be the same as or different from the first dry molding, and preferably the same.

[0095] In the present application, the conditions of the second calcination are selected in a wide range. Preferably, in step (2), the conditions of the second calcination include that the temperature is 350-800℃ and the time is 0.5-6h; further preferably, the conditions of the second calcination include that the temperature is 400-650℃ and the time is 0.5-2h.

[0096] The third aspect of the present application provides an application of the composition for catalytic conversion of waste plastic oil in the catalytic conversion of waste plastic oil.

[0097] The fourth aspect of the present application provides a method for producing low-carbon olefins by catalytic conversion of waste plastic oil, wherein the method comprises the following steps:

[0098] The waste plastic oil and the catalyst are subjected to contact reaction, and the catalyst is the composition for catalytic conversion of waste plastic oil according to the first aspect;

[0099] The waste plastic oil contains silicon and chlorine, the content of silicon is 1-1000mg / kg, preferably 100-500mg / kg, and the content of chlorine is 1-1000mg / kg, preferably 100-500mg / kg.

[0100] In the present application, the source of the waste plastic oil is not particularly limited, and preferably the waste plastic oil is a liquid product obtained by thermal cracking or catalytic cracking of industrial waste plastic. Generally, the source of waste plastic oil is complex, and the high content of silicon additive in waste plastic oil causes many adverse effects on the subsequent processing of waste plastic oil. By utilizing waste plastic oil from industrial waste plastic, waste is turned into treasure, which provides an important development path for waste resources, and has high industrial promotion value.

[0101] In the present application, preferably, the distillation range of the waste plastic oil is 100-600℃, further preferably 150-550℃.

[0102] In the present application, preferably, the waste plastic oil contains n-alkanes, cycloalkanes, olefins and aromatic hydrocarbons.

[0103] In the present application, preferably, the content of n-alkanes in the waste plastic oil is 5-50%, the content of cycloalkanes and olefins is 10-50%, and the content of aromatics is 5-50%, based on the total weight of the waste plastic oil.

[0104] In the present application, the conditions of the contacting reaction are selected in a wide range. Preferably, the conditions of the contacting reaction include a reaction temperature of 450-600 DEG C and a mass ratio of catalyst to oil of 5-20:1; further preferably, the conditions of the contacting reaction include a reaction temperature of 500-600 DEG C and a mass ratio of catalyst to oil of 8-15:1.

[0105] The method provided by the present application, in view of the characteristics of the waste plastic oil containing silicon and chlorine, wide distillation range and high content of cycloalkanes and olefins, selects a catalyst composition of the aluminum-rich catalyst A and the silicon-rich catalyst B with mesoporous and macroporous structures, which can efficiently capture and accommodate the organic silicon species in the waste plastic oil, improve the ability of the waste plastic oil hydrocarbon components to catalytically convert to generate low-carbon olefins, and improve the yield of low-carbon olefins.

[0106] The present application will be described in detail below through preparation examples and examples.

[0107] The raw materials used in the following preparation examples and examples are described as follows:

[0108] The kaolin is produced by Suzhou Kaolin Company, and the solid content is 76% by weight.

[0109] The mesoporous and macroporous pseudo-boehmite is prepared from aluminum sulfate and sodium metaaluminate, and the properties are shown in Table 1.

[0110] Na2CO3: National Pharmaceutical Group.

[0111] The content of alumina in the aluminum sol is 22% by weight.

[0112] The solid content of the acidified pseudo-boehmite is 12.0% by weight, and the acid (HCl) and alumina are acidified at a molar ratio of 0.20.

[0113] The content of silicon oxide in the silicon sol is 30% by weight.

[0114] The phosphorus-modified ZSM-5 molecular sieve has a solid content of 82% by weight, a molar ratio of SiO2 to Al2O3 of 45, a Na2O content of 0.12% by weight, and a P2O5 content of 2.1% by weight.

[0115] The hydrogen-type β molecular sieve has a solid content of 75% by weight, a molar ratio of SiO2 to Al2O3 of 25, and a Na2O content of 0.15% by weight.

[0116] Solid content: Take pseudo-boehmite w1 g, after 800℃ constant temperature treatment for 1h, cool in the dryer for 3h, weigh w2 g, solid content=(w1-w2) / w1*100%.

[0117] Specific surface area and pore volume analysis of meso-macroporous pseudo-boehmite, catalyst A and catalyst B: using the ASAP 2405N V1.01 automatic adsorber of American Micromeritics Company, low-temperature static nitrogen adsorption volumetric method, the sample is in 1.33*10 -2 Pa, vacuum degassing at 300℃ for 4h, using N2 as adsorption medium, measuring the adsorption-desorption isotherm of the sample at 77.4K. According to the BET formula, the specific surface area of the sample is calculated, and the volume of N2 adsorbed by the sample at relative pressure p / p0=0.98 is measured and converted into liquid nitrogen volume, i.e. total pore volume. The pore distribution is calculated by the BJH adsorption branch according to the SH / 0572(ASTM D 4641) standard, and the pore volume of the 10-100nm pore part of the sample is calculated.

[0118] Preparation example for illustrating the preparation of meso-macroporous pseudo-boehmite

[0119] Preparation example 1

[0120] 4.6L of aluminum sulfate solution with an aluminum oxide concentration of 50.0g / L and 1.2L of sodium metaaluminate solution with an Al2O3 concentration of 220g / L and a Na2O concentration of 227g / L are added to the neutralization reactor for neutralization reaction at a temperature of 50℃, a pH of 9.0 and a residence time of 20min;

[0121] Na2CO3 solution is added to the slurry after neutralization reaction, the pH is adjusted to 10, and the temperature is heated to 60℃ and kept constant for 10h. The aged slurry is filtered by a vacuum filter, and washed with 90℃ deionized water to obtain a filter cake. The filter cake is spray dried to obtain meso-macroporous pseudo-boehmite P1, and the physicochemical properties are shown in Table 1.

[0122] Preparation example 2

[0123] 4.6L of aluminum sulfate solution with an aluminum oxide concentration of 50.0g / L and 1.2L of sodium metaaluminate solution with an Al2O3 concentration of 220g / L and a Na2O concentration of 227g / L are added to the neutralization reactor for neutralization reaction at a temperature of 45℃, a pH of 9.0 and a residence time of 20min;

[0124] Na2CO3 solution is added to the slurry after neutralization reaction, the pH is adjusted to 10.5, and the temperature is heated to 55℃ and kept constant for 8h. The aged slurry is filtered by a vacuum filter, and washed with 90℃ deionized water to obtain a filter cake. The filter cake is spray dried to obtain meso-macroporous pseudo-boehmite P2, and the physicochemical properties are shown in Table 1.

[0125] Preparation Example 3

[0126] An aluminum sulfate solution with a concentration of 50.0 g / L in terms of alumina of 4.6 L and a sodium metaaluminate solution with a concentration of 220 g / L in terms of Al2O3 and a concentration of 227 g / L in terms of Na2O of 1.2 L were added into a neutralization reactor in parallel flow to perform a neutralization reaction at a temperature of 35°C, a pH of 9.0, and a residence time of 40 min.

[0127] After the neutralization reaction, a Na2CO3 solution was added to the slurry to adjust the pH to 10.5, and the temperature was raised to 45°C and maintained for 3 h. The aged slurry was filtered using a vacuum filter, and washed with deionized water at 90°C to obtain a filter cake. The filter cake was spray dried to obtain mesoporous pseudoboehmite P2, and the physicochemical properties are shown in Table 1.

[0128] Table 1

[0129] Specific surface area, m 2 / g]] Pore volume, mL / g 10-100 nm pore volume fraction, % Solids content, wt.% P1 306 1.10 97.2 70.0 P2 292 1.07 96.7 69.8 P3 284 0.72 83.2 68.8 Conventional pseudoboehmite 228 0.38 10.8 70.0

[0130] Example for illustrating the preparation of a catalyst composition for catalytic conversion of waste plastic oil

[0131] Example 1

[0132] (1) 643 grams of mesoporous pseudoboehmite P1, 395 grams of kaolin, 1136 grams of aluminum sol, and 458 grams of deionized water were mixed for a first mixing and stirring time of 3.0 h, and the solid content of the obtained first slurry was 38% by weight. The first slurry was then spray dried and formed, and calcined at 550°C for 2 hours to obtain the catalyst A1 of the present application.

[0133] (2) 549 grams of phosphorus-modified ZSM-5 molecular sieve, 395 grams of kaolin, and 1080 grams of deionized water were mixed for a second mixing and stirring time of 2.0 h. 833 grams of silica sol were added to the obtained third slurry, and stirring was continued for 30 min. The solid content of the obtained second slurry was 35% by weight. The second slurry was then spray dried and formed, and calcined at 500°C for 1 hour to obtain the catalyst B1 of the present application.

[0134] (3) Catalyst A1 and catalyst B1 were uniformly mixed in a weight ratio of 15:85 to obtain the catalyst composition C1 provided by the present application.

[0135] Example 2

[0136] (1) 500 grams of mesoporous pseudoboehmite P1, 645 grams of kaolin, 727 grams of aluminum sol, and 628 grams of deionized water were mixed for a first mixing and stirring time of 3.5 h, and the solid content of the obtained first slurry was 40% by weight. The first slurry was then spray dried and formed, and calcined at 600°C for 2 hours to obtain the catalyst A2 of the present application.

[0137] (2) The second mixing and stirring time of 600 grams of Hβ molecular sieve, 461 grams of kaolin and 904 grams of deionized water is 2.5h, 667 grams of silica sol is added in the third slurry, and the stirring is continued for 60min, the solid content of the obtained second slurry is 38wt%, then spray drying is performed, and calcination is performed at 550℃ for 1 hour to obtain the catalyst B2 of the present application.

[0138] (3) The third mixing and stirring of the catalyst A2 and the catalyst B2 is uniformly performed at a weight ratio of 25:75 to obtain the catalyst composition C2 provided by the present application.

[0139] Example 3

[0140] (1) The first mixing and stirring time of 714 grams of mesoporous pseudoboehmite P2, 197 grams of kaolin, 909 grams of aluminum sol and 1250 grams of acidified pseudoboehmite is 4.0h, the solid content of the obtained first slurry is 33wt%, then the first slurry is spray dried and formed, and calcination is performed at 500℃ for 2 hours to obtain the catalyst A3 of the present application.

[0141] (2) The second mixing and stirring time of 244 grams of phosphorus modified ZSM-5 molecular sieve, 267 grams of Hβ molecular sieve, 421 grams of kaolin and 1165 grams of deionized water is 4.0h, 933 grams of silica sol is added in the third slurry, and the stirring is continued for 30min, the solid content of the obtained second slurry is 33wt%, then spray drying is performed, and calcination is performed at 500℃ for 1 hour to obtain the catalyst B3 of the present application.

[0142] (3) The third mixing and stirring of the catalyst A3 and the catalyst B3 is uniformly performed at a weight ratio of 10:90 to obtain the catalyst composition C3 provided by the present application.

[0143] Example 4

[0144] (1) The first mixing and stirring time of 929 grams of mesoporous pseudoboehmite P2, 66 grams of kaolin, 1364 grams of aluminum sol and 499 grams of deionized water is 2.0h, the solid content of the obtained first slurry is 35wt%, then the first slurry is spray dried and formed, and calcination is performed at 500℃ for 2 hours to obtain the catalyst A4 of the present application.

[0145] (2) The second mixing and stirring time of 244 grams of phosphorus modified ZSM-5 molecular sieve, 400 grams of Hβ molecular sieve, 197 grams of kaolin and 492 grams of deionized water is 3.0h, 1167 grams of silica sol is added in the third slurry, and the stirring is continued for 30min, the solid content of the obtained second slurry is 41wt%, then spray drying is performed, and calcination is performed at 550℃ for 1 hour to obtain the catalyst B4 of the present application.

[0146] (3) the catalyst A4 and the catalyst B4 are uniformly mixed in a third mixing at a weight ratio of 50:50 to obtain the catalyst composition C4 provided by the application.

[0147] Example 5

[0148] (1) 436 grams of the mesoporous pseudo-boehmite P3, 789 grams of the kaolin, 455 grams of the aluminum sol and 1177 grams of the deionized water are first mixed and stirred for 3.0 hours, the solid content of the obtained first slurry is 35% by weight, then the obtained first slurry is spray-dried and formed, and calcined at 550°C for 2 hours to obtain the catalyst A5 described in the application.

[0149] (2) 549 grams of the phosphorus-modified ZSM-5 molecular sieve, 395 grams of the clay and 1080 grams of the deionized water are second mixed and stirred for 2.0 hours, 833 grams of the silica sol is added into the obtained third slurry, and the stirring is continued for 30 minutes, the solid content of the obtained second slurry is 35% by weight, then the obtained second slurry is spray-dried and formed, and calcined at 500°C for 1 hour to obtain the catalyst B1 described in the application.

[0150] (3) the catalyst A5 and the catalyst B1 are uniformly mixed in a third mixing at a weight ratio of 15:85 to obtain the catalyst composition C5 provided by the application.

[0151] Example 6

[0152] (1) 643 grams of the mesoporous pseudo-boehmite P1, 395 grams of the kaolin, 1136 grams of the aluminum sol and 458 grams of the deionized water are first mixed and stirred for 3.0 hours, the solid content of the obtained first slurry is 38% by weight, then the obtained first slurry is spray-dried and formed, and calcined at 550°C for 2 hours to obtain the catalyst A1 described in the application.

[0153] (2) 366 grams of the phosphorus-modified ZSM-5 molecular sieve, 724 grams of the kaolin and 910 grams of the deionized water are second mixed and stirred for 2.0 hours, 500 grams of the silica sol is added into the obtained third slurry, and the stirring is continued for 30 minutes, the solid content of the obtained second slurry is 40% by weight, then the obtained second slurry is spray-dried and formed, and calcined at 500°C for 1 hour to obtain the catalyst B5 described in the application.

[0154] (3) the catalyst A1 and the catalyst B1 are uniformly mixed in a third mixing at a weight ratio of 15:85 to obtain the catalyst composition C6 provided by the application.

[0155] Example 7

[0156] The catalyst A1 and B1 are prepared according to the method of Example 1, except that in step (3), the catalyst A1 and the catalyst B1 are uniformly mixed in a third mixing at a weight ratio of 5:95 to obtain the catalyst composition C7 provided by the application.

[0157] Comparative Catalyst DC1

[0158] Comparative Catalyst DC1 was prepared according to the method of Example 1 of CN113398982A, and the composition of the obtained comparative catalyst was: ZSM-5 molecular sieve 40% by weight of the catalyst, silicon-containing substance 8.5% by mass of the catalyst calculated as SiO2, aluminum-containing substance 50.0% by mass of the catalyst calculated as Al2O3, and phosphorus pentoxide 1.5% by weight of the catalyst.

[0159] Comparative Catalyst DC2

[0160] Catalyst B1 was prepared according to the method of Example 1, and was used as Comparative Catalyst DC2, and the composition of the obtained comparative catalyst was: phosphorus-modified ZSM-5 molecular sieve 45% by weight of the catalyst, silica sol 25% by weight of the catalyst calculated as SiO2, and kaolin 30% by weight of the catalyst.

[0161] Comparative Catalyst DC3

[0162] Catalyst A1 was prepared according to the method of Example 1, and was used as Comparative Catalyst DC3, and the composition of the obtained comparative catalyst was: mesoporous pseudoboehmite P1 45% by weight of the catalyst, kaolin 30% by weight of the catalyst, and aluminum sol 25% by weight of the catalyst.

[0163] Comparative Catalyst DC4

[0164] 643 grams of conventional pseudoboehmite, 395 grams of kaolin, 1136 grams of aluminum sol, and 458 grams of deionized water were mixed and stirred for 3.0 hours to obtain a first slurry with a solid content of 38% by weight, and then the first slurry was spray-dried and shaped, and calcined at 550°C for 2 hours to obtain the comparative catalyst DC4 of the present application.

[0165] The compositions of the catalyst compositions of the above examples and comparative examples are shown in Table 2.

[0166] Table 2

[0167]

[0168]

[0169]

[0170] Test Example

[0171] The catalyst compositions in the above examples and comparative examples were aged at 800°C for 17 hours in a fixed bed aging device with 100% by volume water vapor, and then evaluated in a FFB device, and the properties of the waste plastic oil used for evaluation were: a density of 852.8 kg / m3at 20°C, a kinematic viscosity at 40°C of 48.5 mm2 / s, a kinematic viscosity at 100°C of 7.5 mm2 / s, a sulfur content of 0.1% by mass, a nitrogen content of 0.1% by mass, and a polyaromatic content of 0.1% by mass. 3H content is 12.0 wt%, Si content is 200 μg·g -1 chlorine content is 300 μg·g -1 distillation range is 165-550℃, paraffin content is 35 wt%, naphthene and total olefin content is 50 wt%, and aromatic content is 14 wt%. The reaction temperature is 580℃, the mass ratio of catalyst to oil is 10.0, and the evaluation results are shown in Table 3.

[0172] Table 3

[0173]

[0174]

[0175] As can be seen from the above table, the catalyst composition for catalytic conversion of waste plastic oil provided by the application is used for catalytic conversion of waste plastic oil to produce low-carbon olefins, which can improve the yield of low-carbon olefins, and at the same time, realizes the catalytic conversion of waste plastic oil.

[0176] The above describes the preferred embodiments of the application in detail, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the application and belong to the protection scope of the application.

Claims

1. A catalyst composition for the catalytic conversion of waste plastic oil, characterized in that, The catalyst composition comprises catalyst A and catalyst B, wherein, based on the total weight of the catalyst composition, the content of catalyst A is 5-60% and the content of catalyst B is 40-95%. Based on the dry weight of catalyst A, catalyst A contains the following components: 30-70% mesoporous boehmite, 10-40% aluminum-based binder, and 5-60% first clay; the total pore volume of catalyst A is not less than 0.3 mL / g; and the pore volume of pores with a diameter of 10-100 nm accounts for more than 65% of the total pore volume of catalyst A. Based on the dry weight of catalyst B, catalyst B contains the following components: 30-60% molecular sieve, 10-40% silicon-based binder and 5-60% secondary clay.

2. The catalyst composition according to claim 1, wherein, Based on the total weight of the catalyst composition, the content of catalyst A is 10-50%, and the content of catalyst B is 50-90%.

3. The catalyst composition according to claim 1 or 2, wherein, The total pore volume of catalyst A is 0.35-0.5 mL / g; And / or, in catalyst A, the pore volume of pores with a diameter of 10-100 nm accounts for 70-95% of the total pore volume; And / or, the specific surface area of ​​catalyst A is 200-400 m². 2 / g; And / or, based on the total weight of catalyst A, the alumina content in catalyst A is 50-99%, preferably 70-99%.

4. The catalyst composition according to any one of claims 1-3, wherein, Based on the dry weight of catalyst A, catalyst A contains the following components: 35-65% mesoporous boehmite, 15-35% aluminum-based binder and 5-50% first clay. Preferably, the total pore volume of the mesoporous pseudoboehmite is not less than 0.5 mL / g, more preferably 0.8-2.5 mL / g, and even more preferably 0.8-1.2 mL / g; Preferably, the pore volume of pores with a diameter of 10-100 nm in the mesoporous pseudoboehmite accounts for more than 80% of the total pore volume, and more preferably 85-98%. Preferably, the specific surface area of ​​the mesoporous pseudoboehmite is 200-500 m². 2 / g; Preferably, the aluminum-based binder is selected from at least one of aluminum sol, acidified boehmite, and aluminum silicate sol, and more preferably aluminum sol.

5. The catalyst composition according to any one of claims 1-4, wherein, In the catalyst B, the pore volume of 5-50 nm pores accounts for more than 80% of the total pore volume, preferably 85-95%. Preferably, the total pore volume of catalyst B is 0.2-0.5 mg / L; Preferably, based on the total weight of catalyst B, the content of silicon oxide in catalyst B is 60-90%, more preferably 70-90%; Preferably, based on the dry weight of catalyst B, catalyst B contains the following components: 35-55% molecular sieve, 15-35% silicon-based binder and 10-50% second clay; Preferably, the molecular sieve is a ZSM-5 molecular sieve and / or a β-type molecular sieve; Preferably, the ZSM-5 molecular sieve is HZSM-5 and / or ZSM-5 containing modified components; Preferably, the modifying component is selected from at least one of rare earth elements, Fe, Zn, Cu, Mg, Zr, Ti, B and phosphorus; Preferably, the silicon-based binder is silica sol and / or aluminum silicate sol, and more preferably silica sol; Preferably, the first clay and the second clay are each independently selected from at least one of kaolin, rettoite, diatomite, montmorillonite, bentonite and sepiolite.

6. A method for preparing a catalyst composition for the catalytic conversion of waste plastic oil according to any one of claims 1-5, wherein, The preparation method includes the following steps: (1) Mix medium- and large-pore pseudo-boehmite, aluminum-based binder, first clay and water to obtain a first slurry, and then dry and calcine the first slurry to obtain catalyst A; (2) Molecular sieve, silicon-based binder, second clay and water are mixed for the second time to obtain a second slurry. Then the second slurry is dried and shaped for the second time and then calcined for the second time to obtain catalyst B. (3) Mix catalyst A and catalyst B for the third time.

7. The method according to claim 6, wherein, In step (1), the conditions for the first mixing include: a time of 0.5-5 hours; Preferably, in step (1), the solid content of the first slurry is 15-45% by weight, preferably 20-40% by weight; Preferably, in step (1), the conditions for the first roasting include: a temperature of 350-800℃ and a time of 0.5-6h.

8. The method according to claim 6 or 7, wherein, In step (2), the conditions for the second mixing include: a time of 0.5-6 hours; Preferably, in step (2), the solid content of the second slurry is 15-45% by weight, preferably 20-40% by weight; Preferably, in step (2), the conditions for the second calcination include: a temperature of 350-800℃ and a time of 0.5-6h.

9. The use of the composition for catalytic conversion of waste plastic oil according to any one of claims 1-5 in the catalytic conversion of waste plastic oil.

10. A method for catalytic conversion of waste plastic oil to produce low-carbon olefins, wherein, The method includes the following steps: Waste plastic oil and a catalyst are reacted in contact, wherein the catalyst is the composition for catalytic conversion of waste plastic oil as described in any one of claims 1-5; The waste plastic oil contains silicon and chlorine, with silicon content ranging from 1 to 1000 mg / kg and chlorine content ranging from 1 to 1000 mg / kg.

11. The method according to claim 10, wherein, The conditions for the contact reaction include: a reaction temperature of 450-600℃ and an agent-to-oil mass ratio of 5-20:1; Preferably, the conditions for the contact reaction include: a reaction temperature of 500-600℃ and an agent-to-oil mass ratio of 8-15:1.

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