A catalytic cracking reaction process and a cracking promoter

Abstract

A catalytic cracking reaction method is characterized in that a mixture of hydrocarbon oil, a cracking catalyst and an additive is contacted under catalytic cracking reaction conditions, the additive is composed of 20-80% of phosphorus-modified ZSM-5 zeolite on a dry basis, 1-70% of inorganic binder on a dry basis and 2-60% of clay on a dry basis, and the phosphorus-modified ZSM-5 zeolite has an electron binding energy of 135.2 eV of phosphorus element in surface phosphorus species of the zeolite and a crystallinity retention degree of 70-110% in XRD analysis after hydrothermal aging of the zeolite at 800 DEG C and 100% water vapor for 17 h.

Description

TECHNICAL FIELD

[0001] The present invention relates to a catalytic cracking reaction method and an aid for the method, more particularly, the present invention relates to a catalytic cracking reaction method and a cracking aid containing a phosphorus-modified ZSM-5 molecular sieve. BACKGROUND

[0002] The cracking reaction of hydrocarbons at high temperature is to convert long-chain hydrocarbons into high-value-added low-carbon olefins such as ethylene and propylene. ZSM-5 molecular sieve is a high-silicon three-dimensional straight channel mesoporous molecular sieve with MFI structure developed by Mobil Oil Corporation of the United States (USP 3702886), which has a unique pore structure and good shape-selective catalysis and isomerization performance. ZSM-5 molecular sieve also has high thermal and hydrothermal stability, high specific surface area, wide range of silicon-aluminum ratio, unique surface acidity and low carbon deposition, etc. ZSM-5 molecular sieve is widely used as a catalyst and a catalyst carrier, and is successfully used in the production processes of alkylation, isomerization, disproportionation, catalytic cracking, methanol-to-gasoline, methanol-to-olefins, etc.

[0003] Since 1983, ZSM-5 molecular sieve has been used as a catalytic cracking octane aid in the catalytic cracking process, aiming to improve the octane number of catalytic cracking gasoline and the selectivity of low-carbon olefins. In the earliest technology reported in US3758403, ZSM-5 is used as an active component for increasing propylene production, and is prepared into an FCC catalyst together with REY. US5997728 discloses a technology of using ZSM-5 molecular sieve as an aid for increasing propylene production, and the molecular sieve is not modified. In the above two technologies, the propylene yield is not high. Although HZSM-5 molecular sieve has good shape-selective performance and isomerization performance, it has the disadvantage of poor hydrothermal stability, and is easily deactivated under harsh high-temperature hydrothermal conditions, which reduces the catalytic performance.

[0004] Mobil Corporation found that phosphorus can improve the hydrothermal stability of ZSM-5 molecular sieve, and after modification of ZSM-5 molecular sieve by phosphorus, the primary cracking products (such as gasoline olefins) can be selectively converted into C3 and C4 olefins, and the yield of low-carbon olefins is improved. After the introduction of an appropriate amount of inorganic phosphorus compound into ZSM-5 molecular sieve after synthesis, the framework aluminum can be stabilized under harsh hydrothermal conditions.

[0005] CN1211469A discloses a five-membered ring molecular sieve composition for high propylene and ethylene yield, which is composed of 85-95% by weight of five-membered ring molecular sieve, 2-10% by weight of phosphorus in oxide form, 0.3-5% by weight of alkaline earth metal in oxide form, and 0.3-5% by weight of transition metal element in oxide form. When the composition is used for catalytic thermal cracking reaction, a higher ethylene yield is obtained.

[0006] US5171921 discloses a phosphorus-modified ZSM-5 molecular sieve having a silica-to-alumina ratio of 20 to 60. The HZSM-5 molecular sieve is impregnated with a phosphorus-containing compound, treated with steam at 500 to 700°C, and used in a reaction for converting C3 to C20 hydrocarbons into C2 to C5 olefins, and has higher activity than HZSM-5 without phosphorus treatment.

[0007] CN102166533A discloses a preparation method of a phosphorus-modified ZSM-5 molecular sieve. The molecular sieve is added to a phosphorus-containing aqueous solution, reacted at a certain pH value, temperature and pressure for a period of time, filtered, dried and calcined to obtain a phosphorus-modified molecular sieve. Then, the phosphorus-modified molecular sieve is added to a rare earth ion-containing aqueous solution, reacted at a certain temperature and pressure for a period of time, filtered, washed, dried and calcined to obtain a composite-modified molecular sieve. The composite-modified molecular sieve has higher hydrothermal stability and microactivity than a model catalyst containing an unmodified or other modified molecular sieve.

[0008] CN106994364A discloses a preparation method of a phosphorus-modified ZSM-5 molecular sieve. The method is to mix a phosphorus-containing compound selected from one or more of phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate with a ZSM-5 molecular sieve having a high alkali metal ion content to obtain a mixture having a phosphorus carrying capacity of at least 0.1wt% of P2O5, dry and calcine the mixture, then perform an ammonium exchange step and a water washing step to reduce the alkali metal ion content to below 0.10wt%, and then dry and hydrothermally age the mixture at 400-1000°C and 100% steam. The phosphorus-containing ZSM-5 molecular sieve obtained by the preparation method has a high total acid amount, excellent cracking conversion rate and propylene selectivity, and a high liquefied gas yield.

[0009] Although the ZSM-5 molecular sieve modified by the organic / inorganic phosphorus compound can inhibit framework dealumination and thus improve hydrothermal stability, and the introduction of the phosphorus species can regulate the acid center properties of the ZSM-5 molecular sieve and improve the cracking conversion rate of long-chain alkanes and the selectivity of low-carbon olefins, in the existing technology, the phosphoric acid or ammonium phosphate salt will self-polymerize into macromolecular phosphorus species such as polyphosphoric acid due to dehydration during calcination, which is easy to accumulate on the outer surface of the molecular sieve, block the pores, reduce the pore volume and specific surface area, and result in low phosphorus-aluminum activation efficiency, so that the phosphorus-modified molecular sieve cannot achieve the ideal effect of improving hydrothermal stability. SUMMARY

[0010] The inventors have found, based on a large number of experiments, that the phosphorus-modified ZSM-5 molecular sieve prepared by using a solid phosphorus compound with a valence of +3 as a precursor has different physicochemical characteristics from the molecular sieve prepared by a conventional +5 valence phosphorus source aqueous solution impregnation method, and can improve the phosphorus-aluminum stabilization efficiency. The hydrothermal stability, cracking activity and low carbon olefin selectivity of the cracking aid with the phosphorus-modified ZSM-5 molecular sieve as an active component are improved. Based on this, the present application is formed.

[0011] Therefore, one of the purposes of the present application is to provide a catalytic cracking reaction method under the participation of a cracking aid with a phosphorus-modified ZSM-5 molecular sieve as an active component, which has different physicochemical characteristics from the conventional phosphorus-containing ZSM-5 molecular sieve and improved molecular sieve phosphorus-aluminum stabilization efficiency; and the second purpose is to provide a cracking aid applied to the reaction method.

[0012] In order to achieve one of the above purposes, the catalytic cracking reaction method provided by the first aspect of the present application is to contact hydrocarbon oil with a mixture of a cracking catalyst and an aid under catalytic cracking reaction conditions, and the aid is composed of a phosphorus-modified ZSM-5 molecular sieve, an inorganic binder and clay, characterized in that the phosphorus-modified ZSM-5 molecular sieve has an electron binding energy of phosphorus element in the surface phosphorus species of the molecular sieve of 135.2 eV and a crystalline retention degree of 70% to 110% in XRD analysis after hydrothermal aging at 800°C and 100% water vapor for 17h.

[0013] In order to achieve the second purpose, the second aspect of the present application provides a cracking aid, which is composed of 20-80% of the phosphorus-modified ZSM-5 molecular sieve on a dry basis, 1-70% of the inorganic binder on a dry basis and 2-60% of the clay on a dry basis, based on the dry weight of the catalytic cracking aid, characterized in that the phosphorus-modified ZSM-5 molecular sieve has an electron binding energy of phosphorus element in the surface phosphorus species of the molecular sieve of 135.2 eV and a crystalline retention degree of 70% to 110% in XRD analysis after hydrothermal aging at 800°C and 100% water vapor for 17h.

[0014] The catalytic cracking reaction method provided by the application is carried out in the presence of a catalytic cracking aid containing a phosphorus-modified ZSM-5 molecular sieve with special physical and chemical parameters; the phosphorus-modified ZSM-5 molecular sieve with special physical and chemical parameters is obtained by modifying a +3 valence phosphorus source with relatively small molecular size; the +3 valence phosphorus source accelerates the migration process of phosphorus species into the pores of the ZSM-5 molecular sieve, the surface enrichment of the phosphorus species is weakened, the coordination of the phosphorus species and framework aluminum is sufficient, and the quantitative phosphorus-containing compound can stabilize more framework aluminum, so that the phosphorus-modified ZSM-5 molecular sieve has excellent hydrothermal stability; after hydrothermal aging at 800 ℃ and 100% water vapor for 17 h, the electron binding energy of phosphorus in the surface phosphorus species is 135.2 eV, and the crystallinity retention in XRD analysis is 70% to 110%; the phosphorus-modified ZSM-5 molecular sieve is applied to the catalytic cracking reaction as an active component of a cracking aid, and the selectivity of ethylene and propylene can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 An XPS (P2p Scan) spectrum of a phosphorus-modified ZSM-5 molecular sieve sample RYB-1 in the aid. DETAILED DESCRIPTION

[0016] The catalytic cracking reaction method provided by the first aspect of the application is that, under catalytic cracking reaction conditions, hydrocarbon oil is contacted with a mixture of a cracking catalyst and an aid, the aid is composed of a phosphorus-modified ZSM-5 molecular sieve, an inorganic binder and clay, and the phosphorus-modified ZSM-5 molecular sieve has the characteristics that, after hydrothermal aging at 800 ℃ and 100% water vapor for 17 h, the electron binding energy of phosphorus in the surface phosphorus species of the molecular sieve is 135.2 eV, and the crystallinity retention in XRD analysis is 70% to 110%.

[0017] In the aid used in the method of the application, the phosphorus-modified ZSM-5 molecular sieve has a phosphorus binding energy of 134.5 eV as characterized by XPS after drying at an atmosphere of air and at 100-120 ℃ during preparation; and the phosphorus binding energy is 135.2 eV after hydrothermal aging at 800 ℃ and 100% water vapor. The phosphoric acid-modified molecular sieve in the prior art has almost unchanged binding energy of 134.8-134.9 eV after drying and aging due to the absence of valence state transition. The binding energy of phosphorus as characterized by XPS represents the chemical environment and valence state of phosphorus, and can indicate the condensation degree and valence state transition of phosphorus species during drying and hydrothermal aging.

[0018] The phosphorus-modified ZSM-5 zeolite used in the method has a higher crystalline retention degree of 70% to 110%, preferably 95% to 110%, after hydrothermal aging at 800 DEG C and 100% steam for 17 hours, which indicates that the phosphorus species is obviously coordinated with the framework aluminum, and the framework aluminum is fully protected, and the hydrothermal stability of the zeolite is excellent.

[0019] The ratio of phosphorus to aluminum in the phosphorus-modified ZSM-5 zeolite used in the method is 0.01 to 5, and the preferred ratio is 0.1 to 3.

[0020] The phosphorus-modified ZSM-5 zeolite used in the method is obtained by mixing and grinding a solid phosphorus-containing compound precursor with a valence state of +3 and HZSM-5 zeolite to obtain a solid mixture, and then performing heating and melting treatment on the solid mixture, and then cooling the solid mixture to room temperature and then performing calcination treatment to obtain the phosphorus-modified ZSM-5 zeolite; or the phosphorus-modified ZSM-5 zeolite is obtained by contacting and impregnating HZSM-5 zeolite with an aqueous solution of a solid phosphorus-containing compound with a valence state of +3, and then drying and calcining to obtain the phosphorus-modified ZSM-5 zeolite. The solid phosphorus-containing compound with a valence state of +3 can be selected from phosphorous acid and / or ammonium phosphite. The impregnation is performed at room temperature for 0.5 to 10 hours with a water-to-zeolite weight ratio of 0.5 to 2. The drying is performed in an air atmosphere at 100 to 120 DEG C for 2 to 24 hours. The calcination is performed in an air atmosphere at 200 to 800 DEG C for 0.5 to 12 hours. The heating and melting treatment is performed at a temperature higher than the melting point of the solid phosphorus-containing compound and lower than the temperature at which the solid phosphorus-containing compound decomposes or dehydrates, and the treatment time is 2 to 72 hours. The molar ratio of the solid phosphorus-containing compound precursor to the HZSM-5 zeolite is (0.1 to 5):1, preferably (0.5 to 2.5):1, wherein the HZSM-5 zeolite is calculated based on aluminum, and the phosphorus-containing compound is calculated based on phosphorus. The HZSM-5 zeolite is obtained by sodium reduction of ZSM-5 zeolite through ammonium exchange to obtain Na2O < 0.1 wt%, and the silica-to-alumina molar ratio is ≥10, usually in the range of 10 to 200.

[0021] The content of the phosphorus-modified ZSM-5 zeolite in the catalyst used in the method is 0.1 to 30 wt%.

[0022] In the mixture of the cracking catalyst and the additive used in the method, the content of the additive is preferably 0.1 to 30 wt%.

[0023] The additive preferably consists of 20-80% of the phosphorus-modified ZSM-5 molecular sieve by dry basis, 1-70% of the inorganic binder by dry basis and 2-60% of the clay by dry basis. More preferably, the phosphorus-modified ZSM-5 molecular sieve by dry basis accounts for 20-75% by weight of the dry basis of the additive, and most preferably, the phosphorus-modified ZSM-5 molecular sieve by dry basis accounts for 25-70% by weight of the dry basis of the additive. The inorganic binder can include the phosphorus-aluminum inorganic binder and / or other inorganic binders. Preferably, the inorganic binder can include 2-45% by weight of the phosphorus-aluminum inorganic binder by dry basis and 5-30% by weight of the other inorganic binders by dry basis.

[0024] The cracking catalyst can be a conventional cracking catalyst used in the art, which consists of a conventional molecular sieve active component of the cracking catalyst, an inorganic binder, clay and the like. The molecular sieve active component of the cracking catalyst includes a Y-type molecular sieve. The Y-type molecular sieve is selected from at least one of a PSRY molecular sieve, a PSRY-S molecular sieve, a rare earth-containing PSRY molecular sieve, a rare earth-containing PSRY-S molecular sieve, a USY molecular sieve, a rare earth-containing USY molecular sieve, a REY molecular sieve, a REHY molecular sieve and a HY molecular sieve.

[0025] In the present application, the hydrocarbon oil is selected from one or more of crude oil, naphtha, gasoline, atmospheric residue, vacuum residue, atmospheric wax oil, vacuum wax oil, straight-run wax oil, propane light / heavy deoiled, coking wax oil and coal liquefaction product. The hydrocarbon oil can contain heavy metal impurities such as nickel, vanadium and the like, and sulfur, nitrogen impurities, for example, the content of sulfur in the hydrocarbon oil can be as high as 3.0% by weight, the content of nitrogen can be as high as 2.0% by weight, and the content of metal impurities such as vanadium and nickel can be as high as 3000 ppm.

[0026] In the present application, the catalytic cracking reaction conditions can be conventional in the art, and preferably include: a reaction temperature of 500-800°C, for example, 550-680°C.

[0027] The second aspect of the present application provides a cracking additive, which, based on the dry weight of the catalytic cracking additive, consists of 20-80% of the phosphorus-modified ZSM-5 molecular sieve by dry basis, 1-70% of the inorganic binder by dry basis and 2-60% of the clay by dry basis, characterized in that the phosphorus-modified ZSM-5 molecular sieve, after hydrothermal aging at 800°C under 100% steam for 17h, has an electron binding energy of phosphorus element in the phosphorus species on the surface of the molecular sieve of 135.2eV, and a crystallinity retention degree of 70%-110% in XRD analysis.

[0028] The phosphorus-modified ZSM-5 molecular sieve in the cracking aid is obtained by mixing and grinding a solid phosphorus compound precursor with valence state of +3 and HZSM-5 molecular sieve to obtain a solid mixture; the solid mixture is subjected to heating and melting treatment, and the solid mixture after the heating and melting treatment is cooled to room temperature and then subjected to calcination treatment to obtain the phosphorus-modified ZSM-5 molecular sieve; or the phosphorus-modified ZSM-5 molecular sieve is obtained by contacting and impregnating HZSM-5 molecular sieve with an aqueous solution of a phosphorus compound with valence state of +3, and then drying and calcining.

[0029] The ratio of phosphorus to aluminum in the phosphorus-modified ZSM-5 molecular sieve in the cracking aid is 0.01-5, preferably 0.1-3, both in terms of moles.

[0030] The inorganic binder in the cracking aid can include a phosphorus-aluminum inorganic binder and / or other inorganic binders. Preferably, the inorganic binder can include 2-45% by weight of the phosphorus-aluminum inorganic binder on a dry basis and 5-30% by weight of the other inorganic binders on a dry basis.

[0031] The phosphorus-aluminum inorganic binder includes 15-40% by weight of aluminum component in terms of Al2O3, 45-80% by weight of phosphorus component in terms of P2O5, and the P / Al weight ratio is 1.0-6.0, the pH value is 1-3.5, and the solid content is 15-60% by weight, based on the dry weight of the phosphorus-aluminum inorganic binder; for example, the phosphorus-aluminum inorganic binder includes 15-40% by weight of aluminum component in terms of Al2O3 and 45-80% by weight of phosphorus component in terms of P2O5; preferably, the phosphorus-aluminum inorganic binder includes 15-35% by weight of aluminum component in terms of Al2O3 and 50-75% by weight of phosphorus component in terms of P2O5, and the P / Al weight ratio is preferably 1.2-6.0, more preferably 2.0-5.0, and the pH value is preferably 1.5-3.0. Preferably, the phosphorus-aluminum inorganic binder includes 20-40% by weight of aluminum component in terms of Al2O3 and 60-80% by weight of phosphorus component in terms of P2O5, based on the dry weight of the phosphorus-aluminum inorganic binder. The phosphorus-aluminum inorganic binder can be prepared by the following steps: alumina source, clay (such as rectorite, kaolin) and water are dispersed into a slurry with a solid content of 5-50% by weight; wherein the alumina source is aluminum hydroxide and / or alumina (such as pseudo-boehmite, SB powder, γ-alumina) that can be peptized by acid, and 15-50 parts by weight of the alumina source in terms of Al2O3; under stirring, concentrated phosphoric acid is added to the slurry in a weight ratio of P / Al=1-6, and the obtained mixed slurry is reacted at 50-99°C for 15-90 minutes; wherein P in the P / Al is the weight of elemental phosphorus in phosphoric acid, and Al is the weight of elemental aluminum in the alumina source.

[0032] The other inorganic binder is selected from at least one of pseudoboehmite, aluminum sol, silica-aluminum sol, and water glass.

[0033] The clay used in the cracking aid provided by the present application is well known to those skilled in the art and can be at least one selected from the group consisting of kaolin, metakaolin, diatomite, sepiolite, attapulgite, montmorillonite, and rectorite, preferably kaolin, metakaolin, and rectorite. The clay is contained in an amount of 2 to 60% by weight on a dry basis, preferably 5 to 55% by weight, and more preferably 15 to 40% by weight, based on the dry weight of the aid.

[0034] In one specific preparation embodiment of the cracking aid provided by the present application, an inorganic binder (e.g., pseudoboehmite, aluminum sol, silica sol, silica-aluminum sol, or a mixture of two or more thereof) is mixed with clay (e.g., kaolin) and water (e.g., deoxygenated ionized water and / or deionized water) to prepare a slurry having a solid content of 10 to 50% by weight, stirred uniformly, and then the pH of the slurry is adjusted to 1 to 4 with an inorganic acid such as hydrochloric acid, nitric acid, phosphoric acid, or sulfuric acid. The pH is maintained, and the mixture is aged at 20 to 80°C for 0 to 2 hours, for example, 0.3 to 2 hours. Aluminum sol and / or silica sol are then added, stirred for 0.5 to 1.5 hours to form a colloid, and then phosphorus-modified ZSM-5 zeolite is added to form a catalyst slurry having a solid content of, for example, 20 to 45% by weight. The catalyst slurry is spray-dried after further stirring to form microspheres. The microspheres are then calcined at, for example, 350 to 650°C or 400 to 600°C, preferably 450 to 550°C, for 0.5 to 6 hours or 0.5 to 2 hours, washed with ammonium sulfate (wherein the washing temperature can be 40 to 70°C, and the ammonium sulfate:microspheres:water ratio is 0.2 to 0.8:1:5 to 15 by weight), until the sodium oxide content is less than 0.25% by weight, washed with water and filtered, and then dried.

[0035] In another specific preparation embodiment of the aid of the present application, phosphorus-modified ZSM-5 zeolite, phosphorus-aluminum inorganic binder, and other inorganic binder are mixed, clay is added, the mixture is slurried, and then spray-dried.

[0036] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and explanatory of the present application and are not intended to limit the present application.

[0037] X-ray diffraction (XRD) patterns were measured on a Rigaku TTR-3 powder X-ray diffractometer. Instrument parameters: copper target (tube voltage 40 kV, tube current 250 mA), scintillation counter, step width 0.02°, scan rate 0.4(°) / min. The ZSM-5 molecular sieve synthesized by the method of Example 1 in CN1056818C was used as a standard sample, and its crystallinity was defined as 100%. The relative crystallinity was expressed in percentage by the ratio of the sum of the peak areas of the five characteristic diffraction peaks between 22.5-25.0° in the X-ray diffraction patterns of the obtained product and the standard sample.

[0038] X-ray photoelectron spectroscopy (XPS) was used to analyze the surface of the molecular sieve and investigate the migration of phosphorus compounds. An ESCALAB 250 X-ray photoelectron spectrometer from Thermo Fisher-VG was used. Instrument parameters: the excitation source was monochromatic Al Kα X-ray with a power of 150 W, and the charge displacement was corrected using the C1s peak (284.8 eV) from the contaminating carbon.

[0039] The instruments and reagents used in the examples of the present application are all commonly used by those skilled in the art, unless otherwise specified.

[0040] The properties of some of the raw materials used in the examples are as follows:

[0041] Pseudo-boehmite is an industrial product produced by Shandong Aluminum Company, with a solid content of 60% by weight.

[0042] Aluminum sol is an industrial product produced by Sinopec Catalyst Qilu Branch Company, with an Al2O3 content of 21.5% by weight.

[0043] Silica sol is an industrial product produced by Sinopec Catalyst Qilu Branch Company, with an SiO2 content of 28.9% by weight and a Na2O content of 8.9%.

[0044] Kaolin is a special kaolin for catalytic cracking catalyst produced by Suzhou Kaolin Company, with a solid content of 78% by weight.

[0045] Rectorite is produced by Hubei Zhongxiang Minglu Rectorite Development Co., Ltd., with a quartz sand content of <3.5% by weight, an Al2O3 content of 39.0% by weight, a Na2O content of 0.03% by weight, and a solid content of 77% by weight.

[0046] SB aluminum hydroxide powder is produced by Condex Company, Germany, with an Al2O3 content of 75% by weight.

[0047] HRY molecular sieve is an industrial product produced by Sinopec Catalyst Changling Branch Company, with a rare earth content of 10% by weight.

[0048] PSRY molecular sieve is an industrial product produced by Sinopec Catalyst Changling Company, Na2O content <1.5 wt%, P2O5 content is 0.8-1.2 wt%, unit cell constant <2.456 nm, crystallinity ≥64%.

[0049] The instruments and reagents used in the embodiments of the present application are all commonly used by those skilled in the art, unless otherwise specified.

[0050] Examples 1-6 illustrate the phosphorus modified ZSM-5 molecular sieve used in the cleavage aid of the present application and its preparation.

[0051] Example 1

[0052] Take 10.8g solid phosphorous acid into 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5h, then transfer to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process at a heating temperature of 100℃ for 10h, after which the sample is naturally cooled to room temperature and taken out; the above sample is calcined at 550℃ for 2h to obtain a phosphorus modified ZSM-5 molecular sieve sample, which is denoted as RYB-1.

[0053] Example 1-1

[0054] Take 10.8g solid phosphorous acid and dissolve it in 145g deionized water at 25℃, stir for 0.5h to obtain a phosphorus-containing aqueous solution, then add 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modify by impregnation method, and after impregnation at 25℃ for 0.5h, transfer to an oven for drying at 120℃ for 12h, and then perform 550℃ calcination treatment in an air atmosphere in a muffle furnace for 2h to obtain a phosphorus modified ZSM-5 molecular sieve comparative sample, which is denoted as RYB-1s.

[0055] Example 2

[0056] Take 15.4g solid diammonium hydrogen phosphite and add it to 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5h, then transfer to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process at a heating temperature of 100℃ for 10h, after which the sample is naturally cooled to room temperature and taken out; the above sample is calcined at 550℃ for 2h to obtain a phosphorus modified ZSM-5 molecular sieve sample, which is denoted as RYB-2.

[0057] Comparative Example 1

[0058] Take 17.4 g of diammonium hydrogen phosphate at 25 ℃ dissolved in 145 g of deionized water, stirring for 0.5 h to obtain a phosphorus-containing aqueous solution, add 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modify by impregnation method, after 0.5 h of impregnation at 25 ℃, move to the oven for 120 ℃ drying for 12 h, carry out 550 ℃ calcination treatment for 2 h in the muffle furnace in air atmosphere, and obtain the phosphorus-modified ZSM-5 molecular sieve comparative sample, marked as D-1.

[0059] Comparative Example 2

[0060] Take 15.1 g of phosphoric acid solution (mass fraction 85 wt%) at 25 ℃ dissolved in 145 g of deionized water, stirring for 0.5 h to obtain a phosphorus-containing aqueous solution, add 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modify by impregnation method, after 0.5 h of impregnation at 25 ℃, move to the oven for 120 ℃ drying for 12 h, carry out 550 ℃ calcination treatment for 2 h in the muffle furnace in air atmosphere, and obtain the phosphorus-modified ZSM-5 molecular sieve comparative sample, marked as D-2.

[0061] In Examples 1, 1-1, 2 and Comparative Examples 1, 2, the phosphorus-aluminum ratio of the phosphorus-containing compound to the molecular sieve is 1.25.

[0062] The XPS (P2p Scan) spectrum of sample RYB-1 is shown in Figure 1 . Figure 1 In the XPS (P2p Scan) spectrum of sample RYB-1, the peak values of 134.5 eV and 135.2 eV represent the electron binding energy of phosphorus element in the surface phosphorus species of sample RYB-1 after drying and after calcination, respectively. The XPS (P2p Scan) spectra of RYB-1s and RYB-2 both have the characteristics of Figure 1 .

[0063] The XRD relative crystallinity and crystallinity retention of RYB-1, RYB-1s, RYB-2, D-1, D-2 before and after hydrothermal aging treatment at 800 ℃, 100% water vapor, 17 h are shown in Table 1.

[0064] Table 1

[0065]

[0066] Example 3

[0067] Take 6.5 g of solid phosphorous acid into 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5 h, then transfer to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process at a heating temperature of 100°C for 10 h. After the end of the process, the sample is naturally cooled to room temperature and taken out. The sample is calcined at 550°C for 2 h to obtain a phosphorus-modified ZSM-5 molecular sieve sample, which is denoted as RYB-3.

[0068] Example 3-1

[0069] Take 6.5 g of solid phosphorous acid into 145 g of deionized water at 25°C, stir for 0.5 h to obtain a phosphorus-containing aqueous solution, and then add 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30). The modification is carried out by the impregnation method, and the sample is immersed at 25°C for 0.5 h, then transferred to an oven for drying at 120°C for 12 h, and then calcined at 550°C for 2 h in an air atmosphere. The obtained phosphorus-modified ZSM-5 molecular sieve is a comparative sample, which is denoted as RYB-3s.

[0070] Example 4

[0071] Take 9.3 g of solid diammonium hydrogen phosphite into 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5 h, then transfer to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process at a heating temperature of 100°C for 10 h. After the end of the process, the sample is naturally cooled to room temperature and taken out. The sample is calcined at 550°C for 2 h to obtain a phosphorus-modified ZSM-5 molecular sieve sample, which is denoted as RYB-4.

[0072] Comparative Example 3

[0073] Take 10.5 g of diammonium hydrogen phosphate into 145 g of deionized water at 25°C, stir for 0.5 h to obtain a phosphorus-containing aqueous solution, and then add 100 g of HZSM-5 molecular sieve (nSiO2 / nAl2O3=30). The modification is carried out by the impregnation method, and the sample is immersed at 25°C for 0.5 h, then transferred to an oven for drying at 120°C for 12 h, and then calcined at 550°C for 2 h in an air atmosphere. The obtained phosphorus-modified ZSM-5 molecular sieve is a comparative sample, which is denoted as D-3.

[0074] Comparative Example 4

[0075] Take 9.2g phosphoric acid solution (mass fraction 85wt%) dissolved in 145g deionized water at 25°C, stirring for 0.5h to obtain a phosphorus-containing aqueous solution, add 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modified by impregnation method, after 0.5h at 25°C, move to the oven for 120°C drying for 12h, 550°C calcination treatment for 2h in air atmosphere in the muffle furnace, the obtained phosphorus modified ZSM-5 molecular sieve is a comparative sample, marked as D-4.

[0076] In examples 3, 3-1, 4 and comparative examples 3, 4, the phosphorus-aluminum ratio of the phosphorus-containing compound to the molecular sieve is 0.75.

[0077] The XPS (P2p Scan) spectra of samples RYB-3, RYB-3s, and RYB-4 all have the characteristics of Figure 1 .

[0078] The XRD relative crystallinity and crystallinity retention of RYB-3, RYB-3s, RYB-4, D-3, D-4 before and after hydrothermal aging treatment at 800°C, 100% water vapor, 17h are shown in Table 2.

[0079] Table 2

[0080]

[0081]

[0082] Example 5

[0083] Take 15.0g solid phosphorous acid and add it to 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5h, then transfer it to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process with a heating temperature of 100°C and a time of 10h, after the end of the process, take out the sample after it naturally cools to room temperature; after calcination treatment at 550°C for 2h, the above sample obtains a phosphorus-modified ZSM-5 molecular sieve sample, marked as RYB-5.

[0084] Example 5-1

[0085] Take 15.0g solid phosphorous acid and dissolve it in 145g deionized water at 25°C, stirring for 0.5h to obtain a phosphorus-containing aqueous solution, add 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modified by impregnation method, after 0.5h at 25°C, move to the oven for 120°C drying for 12h, 550°C calcination treatment for 2h in air atmosphere in the muffle furnace, the obtained phosphorus modified ZSM-5 molecular sieve is a comparative sample, marked as RYB-5s.

[0086] Example 6

[0087] Take 21.7g solid diammonium hydrogen phosphate into 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), grind and mix for 0.5h, then transfer to a Teflon-lined stainless steel high-pressure reaction kettle for a melting process at a temperature of 100℃ for 10h. After the process, the sample is naturally cooled to room temperature and taken out. The sample is calcined at 550℃ for 2h to obtain a phosphorus-modified ZSM-5 molecular sieve sample, which is denoted as RYB-6.

[0088] Comparative Example 5

[0089] Take 24.5g diammonium hydrogen phosphate at 25℃, dissolve in 145g deionized water, stir for 0.5h to obtain a phosphorus-containing aqueous solution, add 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modify by impregnation method, and then transfer to an oven for drying at 120℃ for 12h. The sample is calcined at 550℃ for 2h in an air atmosphere to obtain a phosphorus-modified ZSM-5 molecular sieve comparative sample, which is denoted as D-5.

[0090] Comparative Example 6

[0091] Take 21.4g phosphoric acid solution (mass fraction 85wt%) at 25℃, dissolve in 145g deionized water, stir for 0.5h to obtain a phosphorus-containing aqueous solution, add 100g HZSM-5 molecular sieve (nSiO2 / nAl2O3=30), modify by impregnation method, and then transfer to an oven for drying at 120℃ for 12h. The sample is calcined at 550℃ for 2h in an air atmosphere to obtain a phosphorus-modified ZSM-5 molecular sieve comparative sample, which is denoted as D-6.

[0092] In Examples 5, 5-1, 6 and Comparative Examples 5, 6, the phosphorus-aluminum ratio of the phosphorus-containing compound to the molecular sieve is 1.75.

[0093] The XPS (P2p Scan) spectra of samples RYB-5, RYB-5s, and RYB-6 all have the characteristics of Figure 1 .

[0094] The XRD relative crystallinity and crystallinity retention of RYB-5, RYB-5s, RYB-6, D-5, D-6 before and after hydrothermal aging treatment at 800℃, 100% water vapor, 17h are shown in Table 3.

[0095] Table 3

[0096]

[0097] Examples 7-26 illustrate the catalytic cracking aids of the present application.

[0098] The phosphorus-aluminum inorganic binder used in the examples was prepared by the following process:

[0099] 1. NJ1: 1.91 kg of pseudoboehmite (containing Al203, 1.19 kg), 0.56 kg of kaolin (dry basis 0.5 kg) and 3.27 kg of deionized water were slurried for 30 minutes, and 5.37 kg of concentrated phosphoric acid (mass concentration 85%) was added to the slurry under stirring at a rate of 0.04 kg of phosphoric acid per minute per kg of alumina source, and the temperature was raised to 70°C, and then reacted at this temperature for 45 minutes to obtain the phosphorus-aluminum inorganic binder. The material ratios are shown in Table 4, and the sample number is NJ1.

[0100] 2. NJ2: The preparation process was the same as NJ1, and the material ratios are shown in Table 9, and the sample number is NJ2.

[0101] Table 4

[0102] Phospho-alumina binder number NJ1 NJ2 Pseudo-boehmite, kg 1.91 Al203, kg 1.19 SB, kg 0.94 Al203, kg 0.70 Rectorite, kg 1.28 Dry basis, kg 1.00 Kaolin, kg 0.56 Dry basis, kg 0.50 Phosphoric acid, kg 5.37 5.36 P2O5, kg 3.31 3.30 Deionized water, kg 3.27 6.71 Total, kg 11.11 14.29 Total dry basis, kg 5.00 5.00 Binder solids content, kg / kg 0.45 0.35 P / Al 2.29 3.89 Al203, wt. % 23.82 14.00 P2O5, wt.% 66.18 66.00 Clay, wt.% 10.00 20.00 pH 2.20 2.37

[0103] Examples 7-9

[0104] The phosphorus-modified molecular sieve RYB-1, kaolin and pseudoboehmite of Example 1 were slurried with deionized water for 120 minutes to obtain a slurry with a solid content of 30% by weight, hydrochloric acid was added to adjust the pH of the slurry to 3.0, and then the slurry was further slurried for 45 minutes, then the phosphorus-aluminum inorganic binder NJ1 was added, and after stirring for 30 minutes, the obtained slurry was spray dried to obtain microspheres, and the microspheres were calcined at 500°C for 1 hour to obtain the catalyst, numbered Zcat1.

[0105] The phosphorus-modified molecular sieve RYB-1s, RYB-2 of Example 1-1, Example 2 was used to replace the molecular sieve RYB-1, and the preparation process was the same as described above, to obtain catalysts numbered Zcat2, Zcat3, respectively.

[0106] In the material ratios of Zcat1, Zcat2, Zcat3, the phosphorus-modified molecular sieve accounted for 65%, the kaolin accounted for 20%, the phosphorus-aluminum binder NJ1 accounted for 10%, and the pseudoboehmite accounted for 5%, based on the dry weight.

[0107] Comparative Examples 7, 8

[0108] The preparation process and material ratios were the same as in Example 7, except that the phosphorus-modified molecular sieve D-1, D-2 of Comparative Examples 1, 2 was used to replace the molecular sieve RYB-1, respectively, to obtain comparative catalysts numbered DZCat1, DZCat2, respectively.

[0109] Examples 10-12

[0110] Take the phosphorus modified molecular sieve RYB-3 of example 3, kaolin, add deionized water and aluminum sol to pulp for 120 minutes, get the slurry with solid content of 30wt%, add hydrochloric acid to adjust the slurry pH value to 3.0, then continue to pulp for 45 minutes, then add phosphorus aluminum inorganic binder NJ2, after stirring for 30 minutes, the obtained slurry is spray dried to obtain microspheres, the microspheres are calcined at 500℃ for 1 hour to prepare a catalyst, numbered Zcat4.

[0111] Replace the phosphorus modified molecular sieve RYB-3s and RYB-4 of example 3-1 and example 4 with molecular sieve RYB-3 respectively, and prepare catalysts numbered Zcat5 and Zcat6 respectively according to the above preparation process.

[0112] In the material ratio of Zcat4, Zcat5 and Zcat6, the phosphorus modified ZSM-5 molecular sieve accounts for 55%, kaolin accounts for 30%, phosphorus aluminum binder NJ2 accounts for 10%, and aluminum sol accounts for 5% by weight on a dry basis.

[0113] Comparative examples 9 and 10

[0114] According to the preparation process and material ratio of example 10, the difference is that the phosphorus modified molecular sieve D-3 and D-4 of comparative examples 3 and 4 are respectively replaced with molecular sieve RYB-3 to prepare comparative catalysts numbered DZcat3 and DZcat4 respectively.

[0115] Examples 13-15

[0116] Take the phosphorus modified molecular sieve RYB-5 of example 5, kaolin, add deionized water and aluminum sol to pulp for 120 minutes, get the slurry with solid content of 30wt%, add hydrochloric acid to adjust the slurry pH value to 3.0, then continue to pulp for 45 minutes, then add phosphorus aluminum inorganic binder NJ1, after stirring for 30 minutes, the obtained slurry is spray dried to obtain microspheres, the microspheres are calcined at 500℃ for 1 hour to prepare a catalyst, numbered Zcat7.

[0117] Replace the phosphorus modified molecular sieve RYB-5s and RYB-6 of example 5-1 and example 6 with molecular sieve RYB-5 respectively, and prepare catalysts numbered Zcat8 and Zcat9 respectively according to the above preparation process.

[0118] In the material ratio of Zcat7, Zcat8 and Zcat9, the phosphorus modified ZSM-5 molecular sieve accounts for 60%, kaolin accounts for 20%, phosphorus aluminum binder NJ1 accounts for 10%, and aluminum sol accounts for 5% by weight on a dry basis.

[0119] Comparative examples 11 and 12

[0120] The preparation process and material ratio of Example 13 are adopted, except that the phosphorus modified molecular sieve D-5 and D-6 of Comparative Example 5 and 6 are respectively used to replace the molecular sieve RYB-5 to prepare the contrast aids numbered DZcat5 and DZcat6.

[0121] The following examples illustrate the catalytic cracking method provided by the present application.

[0122] Examples 16-18

[0123] The aids Zcat1-Zcat3 are respectively aged at 800°C under 100% steam atmosphere for 17 hours.

[0124] The aged aids are respectively mixed with the industrial FCC equilibrium catalyst (industrial brand MMC equilibrium catalyst, light oil micro-reaction activity of 63) to make the mixture, and the aid accounts for 10% by weight in the mixture. The mixture is loaded into a fixed bed micro-reaction reactor to evaluate the catalytic cracking ability of the aid to light hydrocarbon, and the evaluation conditions are reaction temperature of 650°C, regeneration temperature of 620°C, and catalyst / oil ratio of 3.2.

[0125] The properties of the raw oil are shown in Table 5. The reaction results are shown in Table 6.

[0126] Comparative Examples 13 and 14

[0127] The preparation process of Example 27 is adopted, except that the contrast catalysts DZcat1 and DZcat2 are respectively used to replace Zcat1. The reaction results are shown in Table 6.

[0128] Table 5

[0129]

[0130]

[0131] Table 6

[0132]

[0133] Examples 19-21

[0134] The aids Zcat4-Zcat6 are respectively aged at 800°C under 100% steam atmosphere for 17 hours. The aged aids are respectively mixed with the industrial FCC equilibrium catalyst (industrial brand MMC equilibrium catalyst, light oil micro-reaction activity of 63) to load into a fixed bed micro-reaction reactor to evaluate the catalytic cracking ability of the aid to light hydrocarbon, and the evaluation conditions are reaction temperature of 650°C, regeneration temperature of 620°C, and catalyst / oil ratio of 3.2. The reaction results are shown in Table 7.

[0135] Comparative Examples 15 and 16

[0136] The same as Example 19, except that Zcat4 was replaced by comparative catalysts DZcat3, DZcat4, respectively. The reaction results are shown in Table 7.

[0137] Table 7

[0138]

[0139] Examples 22-24

[0140] Catalysts Zcat7-Zcat9 were aged at 800°C under 100% steam atmosphere for 17 hours, respectively. The aged catalysts were mixed with commercial FCC equilibrium catalyst (commercially available equilibrium catalyst of brand MMC, having a light oil micro- reactor activity of 63), and were loaded into a fixed bed micro-reactor to evaluate the catalytic cracking ability of the catalysts for light hydrocarbons, under the following conditions: reaction temperature 650°C, regeneration temperature 620°C, catalyst / oil ratio 3.2. The reaction results are shown in Table 8.

[0141] Comparative Examples 17, 18

[0142] The same as Example 35, except that Zcat7 was replaced by comparative catalysts DZcat5, DZcat6, respectively. The reaction results are shown in Table 8.

[0143] Table 8

[0144]

[0145] Examples 25-27

[0146] Catalysts Zcat1-Zcat3 were aged at 800°C under 100% steam atmosphere for 17 hours, respectively. The aged catalysts were mixed with commercial FCC equilibrium catalyst (commercially available equilibrium catalyst of brand MMC, having a light oil micro- reactor activity of 63), and were loaded into a fixed bed micro-reactor to evaluate the catalytic cracking ability of the catalysts for n-tetradecane.

[0147] The evaluation conditions were: reaction temperature 500°C, regeneration temperature 600°C, catalyst / oil ratio 1.28.

[0148] The reaction results are shown in Table 9.

[0149] Comparative Examples 19, 20

[0150] The same as Example 25, except that Zcat1 was replaced by comparative catalysts DZcat1, DZcat2, respectively. The reaction results are shown in Table 9.

[0151] Table 9

[0152]

[0153]

[0154] From the above reaction results, it can be seen that the catalytic cracking aids prepared by modifying ZSM-5 molecular sieves with phosphorus-containing compounds having a valence state of +3 valence of phosphorus are better than those prepared by modifying ZSM-5 molecular sieves with phosphorus-containing compounds having a valence state of +5 valence of phosphorus, the hydrocarbon conversion rate is increased, the coke is reduced, and the ethylene and propylene yields are improved.

Claims

1. A catalytic cracking reaction method, comprising contacting a mixture of hydrocarbon oil and a cracking catalyst and an auxiliary agent under catalytic cracking reaction conditions, wherein the auxiliary agent is composed of phosphorus-modified ZSM-5 molecular sieve, an inorganic binder, and clay, characterized in that... After hydrothermal aging at 800℃ and 100% steam for 17 hours, the phosphorus-modified ZSM-5 molecular sieve exhibits an electron binding energy of 135.2 eV for phosphorus species on its surface and a crystallinity retention of 70%–110% in XRD analysis. The phosphorus-modified ZSM-5 molecular sieve is prepared by one of the following methods: Method 1 involves mixing and grinding a solid phosphorus compound with a phosphorus oxidation state of +3 and HZSM-5 molecular sieve to obtain a solid mixture. The solid mixture is then heated and melted, and after being cooled to room temperature, it is calcined. Method 2 involves contacting and impregnating HZSM-5 molecular sieve with an aqueous solution of a solid phosphorus-containing compound in the +3 oxidation state, followed by drying and calcination. The phosphorus-containing solid compound with a +3 oxidation state is selected from phosphorous acid and / or ammonium phosphite.

2. The catalytic cracking reaction method according to claim 1, characterized in that, After hydrothermal aging at 800℃ and 100% steam for 17 hours, the crystallinity retention of the phosphorus-modified ZSM-5 molecular sieve in XRD analysis was 95%–110%.

3. The catalytic cracking reaction method according to claim 1, characterized in that, The phosphorus-modified ZSM-5 molecular sieve has a ratio of 0.01 to 5 when both phosphorus and aluminum are measured in molar amounts.

4. The catalytic cracking reaction method according to claim 1, characterized in that, The phosphorus-modified ZSM-5 molecular sieve has a ratio of 0.1 to 3 when both phosphorus and aluminum are measured in molar amounts.

5. The catalytic cracking reaction method according to claim 1, characterized in that, In the mixture of the cracking catalyst and an auxiliary agent, the content of the auxiliary agent is 0.1~30% by weight.

6. The catalytic cracking reaction method according to claim 1 or 5, wherein, The active component of the pyrolysis catalyst includes Y-type molecular sieves.

7. The catalytic cracking reaction method according to claim 6, wherein, The Y-type molecular sieve is selected from at least one of PSRY molecular sieve, PSRY-S molecular sieve, rare earth-containing PSRY molecular sieve, rare earth-containing PSRY-S molecular sieve, USY molecular sieve, rare earth-containing USY molecular sieve, REY molecular sieve, REHY molecular sieve and HY molecular sieve.

8. The catalytic cracking reaction method according to claim 1, characterized in that, The additive, on a dry basis, consists of 20-80% phosphorus-modified ZSM-5 molecular sieve, 1-70% inorganic binder, and 2-60% clay.

9. The catalytic cracking reaction method according to claim 1, characterized in that, The catalytic cracking reaction conditions include a reaction temperature of 500-800℃.

10. The catalytic cracking reaction method according to claim 1, characterized in that, The hydrocarbon oil is selected from one or more of the following: crude oil, naphtha, gasoline, atmospheric residue, vacuum residue, atmospheric wax oil, vacuum wax oil, straight-run wax oil, propane light / heavy deoiling, coking wax oil, and coal liquefaction products.

11. A pyrolysis aid, based on the dry weight of the catalytic pyrolysis aid, comprises 20-80% phosphorus-modified ZSM-5 molecular sieve (dry weight), 1-70% inorganic binder (dry weight), and 2-60% clay (dry weight), characterized in that, The phosphorus-modified ZSM-5 molecular sieve, after hydrothermal aging at 800℃ and 100% steam for 17 hours, exhibits an electron binding energy of 135.2 eV for phosphorus species on its surface and a crystallinity retention of 70%–110% in XRD analysis. The phosphorus-modified ZSM-5 molecular sieve is obtained by mixing and grinding a solid phosphorus-containing compound with a +3 valence state of phosphorus and HZSM-5 molecular sieve to obtain a solid mixture, which is then heated and melted. The melted solid mixture is then cooled to room temperature and calcined. Alternatively, the phosphorus-modified ZSM-5 molecular sieve is obtained by contacting and impregnating HZSM-5 molecular sieve with an aqueous solution of a solid phosphorus-containing compound with a +3 valence state of phosphorus, followed by drying and calcination. The solid phosphorus-containing compound with a +3 valence state of phosphorus is selected from phosphorous acid and / or ammonium phosphite.

12. The pyrolysis aid according to claim 11, characterized in that, The phosphorus-modified ZSM-5 molecular sieve has a ratio of 0.01 to 5 when both phosphorus and aluminum are measured in molar amounts.

13. The pyrolysis aid according to claim 11, characterized in that, The phosphorus-modified ZSM-5 molecular sieve has a ratio of 0.1 to 3 when both phosphorus and aluminum are measured in molar amounts.

14. The pyrolysis aid according to claim 11, characterized in that, The impregnation is carried out at a water-to-sieve weight ratio of 0.5 to 2 for 0.5 to 10 hours at room temperature; the drying is carried out in an air atmosphere at 100 to 120°C for 2 to 24 hours; the calcination is carried out in an air atmosphere at 200 to 800°C for 0.5 to 12 hours.

15. The pyrolysis aid according to claim 11, characterized in that, The heating and melting treatment is performed at a temperature higher than the melting point of the solid phosphorus compound with a +3 oxidation state and lower than the temperature at which the solid phosphorus compound with a +3 oxidation state decomposes or dehydrates, and the treatment time is 2 to 72 hours.

16. The pyrolysis aid according to claim 11, characterized in that, The molar ratio of the HZSM-5 molecular sieve to the solid phosphorus-containing compound with a +3 oxidation state is (0.1~2.5):1, wherein the HZSM-5 molecular sieve is calculated as aluminum and the solid phosphorus-containing compound with a +3 oxidation state is calculated as phosphorus.

17. The pyrolysis aid according to claim 16, characterized in that, The molar ratio of the HZSM-5 molecular sieve to a solid phosphorus-containing compound with a +3 valence is (0.5–1.5):

1.

18. The pyrolysis aid according to claim 11, wherein, The inorganic binder includes a phosphorus aluminum inorganic binder, which accounts for 5-40% by weight on a dry basis of additives.

19. The pyrolysis aid according to claim 11, wherein, The inorganic binder also contains at least one selected from boehmite, aluminum sol, silica-alumina sol, and water glass.

20. The pyrolysis aid according to claim 11, wherein, The clay is selected from at least one of kaolin, sepiolite, attapulgite, raptoite, montmorillonite, and diatomite.

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