CN114713277A

CN114713277A - Modified silicon-aluminum molecular sieve with MFI structure and preparation method thereof

Info

Publication number: CN114713277A
Application number: CN202110008847.4A
Authority: CN
Inventors: 罗一斌; 王成强; 欧阳颖; 邢恩会; 舒兴田
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2022-07-08
Anticipated expiration: 2041-01-05
Also published as: CN114713277B

Abstract

A modified Si-Al molecular sieve with MFI structure contains P and metal, P is used as P₂O₅The molar ratio of the metal to the aluminum oxide is more than or equal to 0.01, and the metal accounts for 0.1-10 wt% of the oxide; the molecular sieve has a K value satisfying: k is more than or equal to 70% and less than or equal to 90%, and K is P1/P2 x 100%, wherein P1 represents the phosphorus mass percentage content of the molecular sieve crystal grain measured by an XPS method in any crystal plane vertical depth of 0-2 nm and in a 100 square nanometer area, and P2 represents the phosphorus mass percentage content of the molecular sieve crystal grain measured by an EPMA method in any crystal plane vertical depth of 5-10 nm and in a 100 square nanometer area. The invention improves the hydrothermal stability of the molecular sieve by promoting the coordination of phosphorus species and framework aluminum.

Description

Modified silicon-aluminum molecular sieve with MFI structure and preparation method thereof

Technical Field

The invention relates to a modified molecular sieve and a preparation method thereof, and further relates to a phosphorus and metal modified MFI structure silicon-aluminum molecular sieve and a preparation method thereof.

Background

A typical representation of a molecular sieve having an MFI framework structure is the ZSM-5 molecular sieve, a widely used catalytic material developed in 1972 by Mobil corporation of america. The ZSM-5 molecular sieve has a three-dimensional crossed pore channel structure, the pore channel along the axial direction a is a straight pore, the cross section dimension of the pore channel is 0.54 multiplied by 0.56nm and is approximately circular, the pore channel along the axial direction b is a Z-shaped pore, the cross section dimension of the pore channel is 0.51 multiplied by 0.56nm and is oval. The ZSM-5 molecular sieve has the pore opening composed of ten-membered rings and the size between that of the small-pore zeolite and that of the large-pore zeolite, thereby having unique shape-selective catalysis. The ZSM-5 molecular sieve has the characteristics of unique pore channel structure, good shape-selective catalysis and isomerization performance, high thermal and hydrothermal stability, high specific surface area, wide silicon-aluminum ratio variation range, unique surface acidity and lower carbon content, is widely used as a catalyst and a catalyst carrier, and is successfully used in production processes of alkylation, isomerization, disproportionation, catalytic cracking, gasoline preparation from methanol, olefin preparation from methanol and the like. The ZSM-5 molecular sieve is introduced into catalytic cracking and carbon four-hydrocarbon catalytic cracking, shows excellent catalytic performance, and can greatly improve the yield of low-carbon olefin by utilizing the shape selectivity of the molecule.

Since 1983, ZSM-5 molecular sieve was applied to catalytic cracking process as an octane number promoter for catalytic cracking, aiming at improving the octane number of catalytic cracking gasoline and the selectivity of low-carbon olefin. US3758403 originally reported the preparation of FCC catalysts using ZSM-5 molecular sieves as the active component for propylene production increase, together with REY. US5997728 discloses the use of ZSM-5 molecular sieves without any modification as an aid to propylene production. However, none of them disclose high propylene yields. The HZSM-5 molecular sieve has good shape-selective performance and isomerization performance, but has the defects of poor hydrothermal stability, easy inactivation under harsh high-temperature hydrothermal conditions and reduced catalytic performance.

In the 80 s of the 20 th century, Mobil company found that phosphorus can improve the hydrothermal stability of the ZSM-5 molecular sieve, and meanwhile, phosphorus modifies the ZSM-5 molecular sieve to improve the yield of low-carbon olefin. It is conventional to contain a phosphorus activated ZSM-5 additive that selectively converts primary cracked products (e.g., gasoline olefins) to C3 and C4 olefins. After being synthesized, the ZSM-5 molecular sieve is modified by introducing a proper amount of inorganic phosphorus compound, and can stabilize framework aluminum under harsh hydrothermal conditions.

CN 106994364A discloses a method for modifying a ZSM-5 molecular sieve by phosphorus, which comprises the steps of mixing a phosphorus-containing compound selected from one or more of phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate with the ZSM-5 molecular sieve with high alkali metal ion content to obtain a mixture with P and P of phosphorus₂O₅At least 0.1 wt% of the mixture, drying, calcining, ammonium exchange step and water washing step to reduce the alkali metal ion content to below 0.10 wt%, drying and hydrothermal aging at 400-1000 deg.C and 100% water vapor. The phosphorus-containing ZSM-5 molecular sieve obtained by the method has high total acid content, excellent cracking conversion rate and propylene selectivity and higher liquefied gas yield.

CN1506161A discloses a method for modifying a ZSM-5 molecular sieve, which comprises the following conventional steps: synthesizing → filtering → ammonium exchanging → drying → roasting to obtain ZSM-5 molecular sieve, then modifying the ZSM-5 molecular sieve with phosphoric acid, drying and roasting to obtain the HZSM-5 molecular sieve modified by phosphorus, wherein, P is P₂O₅The loading capacity is usually in the range of 1 to 7% by weight.

CN1147420A discloses a molecular sieve containing phosphorus and rare earth and having MFI structure, and the anhydrous chemical composition of the molecular sieve is aRE₂O₃bNa₂OAl₂O₃cP₂O₅dSiO₂Wherein a is 0.01 to 0.25, b is 0.005 to 0.02, c is 0.2 to 1.0, and d is 35 to 120. The molecular sieve has excellent hydrothermal activity stability and good low-carbon olefin selectivity when being used for high-temperature conversion of hydrocarbons.

Methods for modifying molecular sieves with metals and uses thereof are reported in, for example, USP5,236,880 which discloses catalysts comprising molecular sieves of MFI or MEL structure, which can increase the octane number, aromatic content and/or gasoline yield of C5 to C12 gasoline when the modified molecular sieve-added catalyst is used for conversion of alkanes, and which can increase the octane number of gasoline and increase the yield of C3 to C4 olefins. The molecular sieves used are modified with a group VIII metal, preferably Ni. After Ni is introduced into the molecular sieve, the molecular sieve is subjected to heat or hydrothermal treatment under the harsh controlled temperature, so that the VIII group metal and aluminum are enriched on the surface.

The hierarchical pore ZSM-5 molecular sieve is a ZSM-5 molecular sieve containing micropores and mesopores, and various hierarchical pore ZSM-5 molecular sieves with mesopore pore canals are prepared by a hard template method, a soft template method, an acid-base post-treatment method and the like.

Although the ZSM-5 molecular sieve is modified by adopting a proper amount of inorganic phosphide, the framework dealumination can be slowed down, the hydrothermal stability is improved, and phosphorus atoms can be combined with distorted four-coordination framework aluminum to generate weak B acid centers, so that the higher conversion rate of long paraffin cracking and the higher selectivity of light olefin are achieved, the excessive inorganic phosphide is used for modifying the ZSM-5 molecular sieve, so that the pore channels of the molecular sieve are blocked, the pore volume and the specific surface area are reduced, and a large amount of strong B acid centers are occupied. In addition, in the prior art, when inorganic phosphorus is modified by phosphorus, excessive phosphorus compounds are used, phosphoric acid or ammonium phosphate salts can generate phosphorus species in different aggregation states by self polymerization in the roasting process, the dispersion degree of the phosphorus species is poor, so that the coordination of phosphorus and framework aluminum is insufficient, the utilization efficiency of phosphorus is low, and the phosphorus modification does not always obtain a satisfactory hydrothermal stability improvement result. Therefore, new technologies are urgently needed to promote the coordination of phosphorus and framework aluminum, improve the hydrothermal stability of phosphorus and metal modified ZSM-5 molecular sieves, and further improve the cracking activity.

Disclosure of Invention

One of the objects of the present invention is to provide a phosphorus and metal modified MFI structure silicoaluminophosphate molecular sieve, different from the prior art, having a high degree of dispersion of phosphorus species; the other purpose is to provide a method for modifying MFI structure molecular sieve by phosphorus and metal.

In order to achieve one of the purposes, the invention provides a modified MFI structure silicoaluminophosphate molecular sieve which contains phosphorus and metal, wherein the phosphorus is P₂O₅The molar ratio of the metal to the aluminum oxide is more than or equal to 0.01, and the metal accounts for 0.1-10 wt% of the oxide; the molecular sieve has a K value satisfying: k is more than or equal to 70% and less than or equal to 90%, and K is P1/P2 x 100%, wherein P1 represents phosphorus in the area of 100 square nanometers with the vertical depth of any crystal face of the molecular sieve crystal grain measured by an XPS method within 0-2 nmAnd P2 represents the phosphorus mass content in the area of a 100 square nanometer region in the thickness range of 5-10 nm of the vertical depth of any crystal face of the molecular sieve crystal grain measured by the EPMA method.

In the molecular sieve of the invention, the content of phosphorus is P₂O₅The molar ratio to alumina is 0.01 or more, preferably 0.2 or more, more preferably 0.3 or more, most preferably 0.4 to 0.7.

Wherein, the MFI structure molecular sieve is a microporous ZSM-5 molecular sieve or a hierarchical pore ZSM-5 molecular sieve. The microporous ZSM-5 molecular sieve has a silica/alumina molar ratio of 15-1000, preferably 20-200.

The multi-stage pore ZSM-5 molecular sieve has the advantages that the proportion of mesoporous volume to total pore volume is more than 10%, the average pore diameter is 2-20 nm, and the molar ratio of silicon oxide to aluminum oxide is 15-1000, preferably 20-200.

The metal is selected from one or more of VIII, IIB, VIIB, IIIA, IVA and lanthanide metals; further, the metal is selected from one or more of Fe, Co, Ni, Zn, Mn, Ga, Sn, La and Ce, and the metal accounts for 0.1-10 wt%, preferably 0.2-5 wt% of oxide.

In order to achieve the second purpose, the invention also provides a method for modifying the MFI structure silicon-aluminum molecular sieve, which is characterized in that an impregnation method is used for mixing and contacting an aqueous solution of a phosphorus-containing compound with the temperature of 40-150 ℃, preferably 50-150 ℃ and more preferably 70-130 ℃ with the MFI structure molecular sieve with the temperature of 40-150 ℃, preferably 50-150 ℃ and more preferably 70-130 ℃ at the basically same temperature for at least 0.1 hour, and a product obtained by drying and roasting at 200-600 ℃ in an air or steam atmosphere for at least 0.1 hour is impregnated with a solution of a metal compound and roasted; or,

mixing and pulping a phosphorus-containing compound, an MFI structure molecular sieve and water, heating to 40-150 ℃, preferably 50-150 ℃, more preferably 70-130 ℃, keeping for at least 0.1 hour, drying, roasting at 200-600 ℃ in air or steam atmosphere for at least 0.1 hour, and impregnating and roasting a product obtained by roasting at least 0.1 hour with a solution of a metal compound; or,

mixing and pulping a phosphorus-containing compound, a metal compound, an MFI structure molecular sieve and water, heating to 40-150 ℃, preferably 50-150 ℃, more preferably 70-130 ℃, keeping for at least 0.1 hour, drying, and roasting for at least 0.1 hour at 200-600 ℃ in an air or steam atmosphere.

In the method provided by the invention, the MFI structure molecular sieve can be a hydrogen type microporous ZSM-5 silicon aluminum molecular sieve or a hydrogen type hierarchical pore ZSM-5 silicon aluminum molecular sieve. They are all reduced to Na by ammonium exchange₂O<0.1 wt%, and the silicon-aluminum ratio (the molar ratio of silicon oxide to aluminum oxide) is more than or equal to 10, and is usually 10-200.

In the method provided by the invention, the phosphorus-containing compound is calculated by phosphorus, and the hydrogen type ZSM-5 molecular sieve or the hydrogen type hierarchical pore ZSM-5 molecular sieve is calculated by aluminum, wherein the molar ratio of the phosphorus-containing compound to the hydrogen type ZSM-5 molecular sieve or the hydrogen type hierarchical pore ZSM-5 molecular sieve is 0.01-2; preferably, the molar ratio of the two is 0.1-1.5; more preferably, the molar ratio of the two is 0.2 to 1.5. The phosphorus-containing compound is selected from organic phosphorus, such as trimethyl phosphate, triphenyl phosphorus, trimethyl phosphite, tetrabutyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrabutyl phosphonium hydroxide, triphenyl ethyl phosphonium bromide, triphenyl butyl phosphonium bromide, triphenyl benzyl phosphonium bromide, hexamethyl phosphoric triamide, dibenzyl diethyl phosphonium, 1, 3-xylene bis triethyl phosphonium, and the like, inorganic phosphide, such as one of phosphoric acid, ammonium hydrogen phosphate, diammonium hydrogen phosphate or ammonium phosphate, boron phosphate or a mixture thereof, and the like.

The inventor finds that when boron phosphate is taken as one of the phosphorus-containing compounds and hydrothermal roasting is carried out at 300-500 ℃, phosphorus has better dispersity in the molecular sieve, so the preferable combination of the phosphorus-containing compounds is a mixture of boron phosphate and phosphorus selected from trimethyl phosphate, triphenyl phosphorus, trimethyl phosphite, phosphoric acid, ammonium hydrogen phosphate, diammonium hydrogen phosphate and ammonium phosphate. In the above mixture containing boron phosphate, the weight ratio of boron phosphate is 10% to 80%, preferably 20% to 40%, more preferably 25% to 35%.

The method provided by the invention is characterized in that the contact is carried out by contacting an aqueous solution of a phosphorus-containing compound with the temperature of 40-150 ℃ with a hydrogen MFI structure molecular sieve with the temperature of 40-150 ℃ for at least 0.1 hour at the basically same temperature by an immersion method. For example, the contacting may be performed at a higher temperature range of 40 ℃ or higher, for example, 50 to 150 ℃, more preferably 70 to 130 ℃, so that a better effect can be obtained, that is, the phosphorus species are better dispersed, the phosphorus is more easily migrated into the crystals of the hydrogen MFI structure molecular sieve to be combined with the framework aluminum, the coordination degree of the phosphorus and the framework aluminum is further improved, and finally, the improvement of the hydrothermal stability of the molecular sieve is contributed. The substantially same temperature means that the temperature difference between the aqueous solution of the phosphorus-containing compound and the hydrogen MFI structure molecular sieve is within. + -. 5 ℃. For example, the temperature of the aqueous solution of the phosphorus-containing compound is 80 ℃ and the HZSM-5 molecular sieve is heated to 75-85 ℃.

The method provided by the invention can also be used for keeping the phosphorus-containing compound (or the phosphorus-containing compound and the metal compound), the hydrogen MFI structure molecular sieve and water at 40-150 ℃ for at least 0.1 hour after mixing. For example, after mixing, the mixture is kept at a higher temperature range of 40 ℃ or higher for 0.1 hour, preferably, in order to obtain better effects, i.e., better dispersion of phosphorus species, easier migration of phosphorus into molecular sieve crystals to bond with framework aluminum, further improvement of coordination degree of phosphorus and framework aluminum, and finally improvement of hydrothermal stability of the molecular sieve, after mixing the phosphorus-containing compound, the hydrogen type MFI structure molecular sieve and water, the temperature range is preferably 50 to 150 ℃, more preferably 70 to 130 ℃.

The contact is carried out for 0.5-40 hours, wherein the weight ratio of the water sieve is 0.5-1. The roasting is preferably carried out at 450-550 ℃ in an air atmosphere.

The method provided by the invention is characterized in that the metal compound is a water-soluble salt of one or more metals selected from VIII, IIB, VIIB, IIIA, IVA and lanthanide metals. The water-soluble salt of the metal is preferably selected from the group consisting of a sulfate, nitrate or chloride salt. For example, iron nitrate, cobalt nitrate, nickel nitrate, manganese nitrate, potassium nitrate, zinc sulfate, tin chloride, lanthanum nitrate, cerium chloride, and the like.

The invention improves the hydrothermal stability of the phosphorus modified molecular sieve by promoting the coordination of phosphorus species and the MFI structure molecular sieve framework aluminum. In the cracking of n-tetradecane, the modified MFI structure molecular sieve has excellent cracking conversion rate and yield of low-carbon olefin, and simultaneously has higher yield of liquefied gas.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

In the examples and comparative examples, phosphorus content quantitative analysis is performed by using an EPMA/SEM combined method to analyze chemical components of the micro-region by surface scanning and corresponding to a depth structure, and a dispersion K value is a percentage of phosphorus content on the surface of the molecular sieve crystal grain and phosphorus content on a depth interface of the molecular sieve crystal grain, wherein K is P1(XPS)/P2 (EPMA)%, P1(XPS) represents phosphorus content of a micro-region with any crystal plane depth of less than 2nm quantitatively determined by using the XPS method, and P2(EPMA) represents phosphorus content of a micro-region with a depth interface of 5-10 m thickness quantitatively determined by using the EPMA method and cutting by using a Focused Ion Beam (FIB).

Examples 1-13 illustrate the modified hierarchical pore ZSM-5 molecular sieves and methods of the present invention.

Examples 1 to 1

Taking 18.5g of diammonium hydrogen phosphate and 108g of hydrogen type multi-stage hole ZSM-5 molecular sieve (provided by Qilu Branch of China petrochemical catalyst company, the relative crystallinity is 88.6 percent, the molar ratio of silicon oxide to aluminum oxide is 20.8, and Na is added₂The content of O is 0.017 percent by weight, and the specific surface area is 373m²(per gram), the total pore volume is 0.256ml/g, the mesoporous volume is 0.119 ml/g, the average pore diameter is 5.8nm, the same applies below) and 60g of deionized water, heating to 100 ℃ and keeping for 2 hours, drying in an oven at 110 ℃, and roasting in air at 550 ℃ for 2 hours to obtain the phosphorus-containing hierarchical pore ZSM-5 molecular sieve. And dissolving 1.8g of ferric nitrate in 60g of deionized water again, modifying by adopting a dipping method, mixing, dipping and drying the obtained ZSM-5 molecular sieve sample containing phosphorus, and roasting the obtained sample at 550 ℃ for 2 hours to obtain a phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample which is GPMZ 1-1.

Comparative examples 1 to 1

The same as example 1-1, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with a phosphorus-containing aqueous solution at 20 ℃. A comparative sample of the phosphorus and iron modified hierarchical pore ZSM-5 molecular sieve was obtained and was designated D1-1.

Examples 1 to 2

Similar to example 1-1, except that after drying, the porous ZSM-5 molecular sieve was treated at 450 ℃ under 60% steam atmosphere for 0.5h to obtain a phosphorus and iron modified porous ZSM-5 molecular sieve sample designated GPMZ 1-2.

Comparative examples 1 to 2

The same as example 1-2, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with a phosphorus-containing aqueous solution at 20 ℃. A comparative sample of the phosphorus and iron modified hierarchical pore ZSM-5 molecular sieve was obtained and was designated D1-2.

The phosphorus dispersity K of GPMZ-1, D1-1, GPMZ1-2 and D1-2 is shown in Table 1-1.

The n-tetradecane cracking evaluation was carried out on GPMZ-1, D1-1, GPMZ1-2 and D1-2 after hydrothermal aging treatment at 800 ℃ for 17 hours with 100% steam. Micro-reverse evaluation conditions: the molecular sieve loading is 2g, the raw oil is n-tetradecane, the oil inlet amount is 1.56g, the reaction temperature is 550 ℃, and the regeneration temperature is 600 ℃ (the same below).

The evaluation data are shown in tables 1-2.

TABLE 1-1

Tables 1 to 2

Example 2-1

Mixing 18.5g of diammonium hydrogen phosphate, 108g of hydrogen type multistage hole ZSM-5 molecular sieve and 120g of deionized water, beating into slurry, keeping the slurry at 70 ℃ for 2 hours, drying the slurry in an oven at 110 ℃, and roasting the dried slurry in air at 550 ℃ for 2 hours to obtain the phosphorus-containing ZSM-5 molecular sieve; and dissolving 2.1g of cobalt nitrate in 60g of deionized water again, mixing, impregnating and drying the obtained ZSM-5 molecular sieve sample containing phosphorus by modification by an impregnation method, and roasting the obtained sample at 550 ℃ for 2 hours to obtain a hierarchical pore ZSM-5 molecular sieve sample containing phosphorus and cobalt, wherein the hierarchical pore ZSM-5 molecular sieve sample is marked as GPZ 2-1.

Comparative example 2 to 1

The same as example 2-1, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with a phosphorus-containing aqueous solution at 20 ℃. A comparative sample of the phosphorus and cobalt modified hierarchical pore ZSM-5 molecular sieve was obtained and designated D2-1.

Examples 2 to 2

Similar to example 2-1, except that after drying, the porous ZSM-5 molecular sieve was treated at 600 ℃ for 2 hours in a 50% steam atmosphere to obtain a sample of phosphorus and cobalt modified hierarchical pore ZSM-5 molecular sieve designated GPMZ 2-2.

Comparative examples 2 to 2

The difference from example 2-2 is that the hydrogen-type hierarchical pore ZSM-5 molecular sieve was impregnated with an aqueous solution containing phosphorus by an impregnation method at 20 ℃ to obtain a comparative sample of phosphorus-and cobalt-modified hierarchical pore ZSM-5 molecular sieve, which was designated as D2-2.

The phosphorus dispersity K of GPMZ2-1, D2-1, GPMZ2-2 and D2-2 is shown in Table 2-1.

GPMZ2-1, D2-1, GPMZ2-2 and D2-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 2-2.

TABLE 2-1

Tables 2 to 2

Example 3-1

Dissolving 11.8g of phosphoric acid and 2.1g of nickel nitrate in 60g of deionized water, and stirring for 2 hours to obtain a water solution containing phosphorus and nickel; taking 108g of a hydrogen type multistage hole ZSM-5 molecular sieve; and respectively heating the aqueous solution containing phosphorus and nickel and the hydrogen-type hierarchical pore ZSM-5 molecular sieve to 80 ℃, mixing and contacting for 4 hours, drying in an oven at the temperature of 110 ℃, and roasting in air at the temperature of 550 ℃ for 2 hours to obtain a phosphorus and nickel modified hierarchical pore ZSM-5 molecular sieve sample, which is marked as GPMZ 3-1.

Comparative example 3-1

The difference from the example 3-1 is that the hydrogen type multi-stage pore ZSM-5 molecular sieve is impregnated with an aqueous solution of phosphoric acid and nickel nitrate at 20 ℃. The comparative phosphorus and nickel modified hierarchical pore ZSM-5 molecular sieve sample obtained was designated as D3-1.

Examples 3 to 2

Similar to example 3-1, except that after drying, the porous ZSM-5 molecular sieve was treated at 430 ℃ for 2 hours in a 100% steam atmosphere to obtain a phosphorus and nickel modified porous ZSM-5 molecular sieve sample designated GPMZ 3-2.

Comparative examples 3 to 2

The difference from example 3-2 is that the hydrogen-type multi-stage pore ZSM-5 molecular sieve is impregnated with an aqueous solution of phosphoric acid and nickel nitrate at 20 ℃. The comparative phosphorus and nickel modified hierarchical pore ZSM-5 molecular sieve sample obtained was designated as D3-2.

The phosphorus dispersity K of GPMZ3-1, D3-1, GPMZ3-2 and D3-2 is shown in Table 3-1.

GPMZ3-1, D3-1, GPMZ3-2 and D3-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 3-2.

TABLE 3-1

TABLE 3-2

Example 4-1

9.3g of diammonium hydrogen phosphate, 1.2 g of zinc sulfate, 108g of hydrogen type hierarchical pore ZSM-5 molecular sieve and 120g of deionized water are mixed and beaten into slurry, the slurry is kept at 90 ℃ for 2 hours, the slurry is dried in an oven at 110 ℃, and then air roasting is carried out at 550 ℃ for 2 hours to obtain the phosphorus and zinc modified hierarchical pore ZSM-5 molecular sieve, which is marked as GPMZ 4-1.

Comparative example 4-1

The difference from example 4-1 is that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium hydrogen phosphate and zinc sulfate at 20 ℃. The obtained phosphorus and zinc modified hierarchical pore ZSM-5 molecular sieve comparison sample is marked as D4-1.

Example 4 to 2

Similar to example 4-1, except that after drying, the porous ZSM-5 molecular sieve was treated at 350 ℃ for 2 hours in a 100% steam atmosphere to obtain a phosphorus and zinc modified porous ZSM-5 molecular sieve sample designated GPMZ 4-2.

Comparative examples 4 to 2

The difference from example 4-2 is that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium hydrogen phosphate and zinc sulfate at 20 ℃. A comparative sample of phosphorus and zinc modified hierarchical pore ZSM-5 molecular sieve was obtained and is designated D4-2.

The phosphorus dispersity K of GPMZ4-1, D4-1, GPMZ4-2 and D4-2 is shown in Table 4-1.

GPMZ4-1, D4-1, GPMZ4-2 and D4-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 4-2.

TABLE 4-1

TABLE 4-2

Example 5-1

Mixing and pulping 9.7g of trimethyl phosphate, 1.5 g of manganese nitrate, 108g of hydrogen type multi-stage hole ZSM-5 molecular sieve and 80g of deionized water, heating to 120 ℃, keeping the temperature for 8 hours, drying in an oven at 110 ℃, and roasting in air at 550 ℃ for 2 hours to obtain a phosphorus and manganese modified multi-stage hole ZSM-5 molecular sieve sample, which is marked as GPMZ 5-1.

Comparative example 5-1

The same as example 5-1, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of trimethyl phosphate and manganese nitrate at 20 ℃. The obtained phosphorus and manganese modified hierarchical pore ZSM-5 molecular sieve comparison sample is marked as D5-1.

Examples 5 and 2

Similar to example 5-1, except that after drying, the calcination treatment was carried out at 500 ℃ for 4 hours in a 40% steam atmosphere, to obtain a phosphorus and manganese modified hierarchical porous ZSM-5 molecular sieve sample, which was designated as GPMZ 5-2.

Comparative examples 5 to 2

The same as example 5-2, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of trimethyl phosphate and manganese nitrate at 20 ℃. A phosphorus and manganese modified hierarchical pore ZSM-5 molecular sieve comparison sample was obtained and is marked as D5-2.

The phosphorus dispersity K of GPMZ5-1, D5-1, GPMZ5-2 and D5-2 is listed in Table 5-1.

GPMZ5-1, D5-1, GPMZ5-2 and D5-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 5-2.

TABLE 5-1

TABLE 5-2

Example 6-1

Mixing and beating 13.2g of boron phosphate, 2.0 g of gallium nitrate, 108g of hydrogen type hierarchical pore ZSM-5 molecular sieve and 100g of deionized water to obtain slurry, keeping the slurry at 150 ℃ for 2 hours, drying the slurry in an oven at 110 ℃, and roasting the slurry in air at 550 ℃ for 2 hours to obtain a phosphorus and gallium modified hierarchical pore ZSM-5 molecular sieve sample, which is marked as GPMZ 6-1.

Comparative example 6-1

The same as example 6-1, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of boron phosphate and gallium nitrate at 20 ℃. The obtained phosphorus and gallium modified hierarchical pore ZSM-5 molecular sieve comparison sample is marked as D6-1.

Example 6 to 2

The same as example 6-1, except that the drying was followed by hydrothermal calcination at 350 ℃ in an atmosphere of 60% steam for 4 hours, to obtain a phosphorus and gallium modified hierarchical pore ZSM-5 molecular sieve sample, which was designated GPMZ 6-2.

Comparative examples 6 to 2

The difference from example 6-2 is that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of boron phosphate and gallium nitrate at 20 ℃. The obtained phosphorus and gallium modified hierarchical pore ZSM-5 molecular sieve comparison sample is marked as D6-2.

The phosphorus dispersity K of GPMZ6-1, D6-1, GPMZ6-2 and D6-2 is listed in Table 6-1.

GPMZ6-1, D6-1, GPMZ6-2 and D6-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 6-2.

TABLE 6-1

TABLE 6-2

Example 7-1

Dissolving 16.3g of triphenyl phosphine and 2.0 g of stannic chloride in 80g of deionized water, and stirring for 2 hours to obtain a phosphorus-containing aqueous solution; taking 108g of a hydrogen type multistage hole ZSM-5 molecular sieve; and respectively heating the phosphorus-containing aqueous solution and the hydrogen-type hierarchical pore ZSM-5 molecular sieve to 80 ℃, mixing and contacting for 4 hours, drying in an oven at 110 ℃, and roasting in air at 550 ℃ for 2 hours to obtain a phosphorus and tin modified hierarchical pore ZSM-5 molecular sieve sample, which is marked as GPMZ 7-1.

Comparative example 7-1

The same as example 7-1, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of triphenylphosphine and tin chloride at 20 ℃. A comparative sample of the resulting phosphorus and tin containing hierarchical pore ZSM-5 molecular sieve was designated D7-1.

Example 7-2

Similar to example 7-1, except that after drying, calcination was carried out at 600 ℃ under 50% steam atmosphere for 2h, and a phosphorus and tin modified hierarchical pore ZSM-5 molecular sieve sample was obtained and was designated GPMZ 7-2.

Comparative examples 7 to 2

The same as example 7-2, except that the hydrogen-type multi-stage pore ZSM-5 molecular sieve was impregnated with an aqueous solution of triphenylphosphine and tin chloride at 20 ℃. The obtained phosphorus and tin modified hierarchical pore ZSM-5 molecular sieve comparison sample is marked as D7-2.

The phosphorus dispersity K of GPMZ7-1, D7-1, GPMZ7-2 and D7-2 is listed in Table 7-1.

GPMZ7-1, D7-1, GPMZ7-2 and D7-2 are subjected to hydrothermal aging treatment at 800 ℃ for 17 hours with 100 percent of water vapor, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 7-2.

TABLE 7-1

TABLE 7-2

Example 8-1

The same as example 4-1 except that the phosphorus source was diammonium phosphate and crystalline boron phosphate in a weight ratio of 3:1, and the metal salt was 1.8g of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 8-1.

Example 8 to 2

The same as example 4-2, except that the phosphorus source was diammonium phosphate and crystalline boron phosphate in a weight ratio of 3:1, and the metal salt was 1.8g of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 8-2.

Example 9-1

Same as the embodiment4-1The difference is that the phosphorus source is diammonium hydrogen phosphate and crystalline boron phosphateThe weight ratio was 2:2, the metal salt was 1.8 grams of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 9-1.

Example 9-2

Same as the embodiment4-2The difference is that the phosphorus source is diammonium phosphate and crystalline boron phosphate, the weight ratio of the diammonium phosphate to the crystalline boron phosphate is 2:2, and the metal salt solution is 1.8g of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 9-2.

Example 10-1

Same as the embodiment4-1, the difference is that the phosphorus source is diammonium hydrogen phosphate and crystalline boron phosphate, the weight ratio of the diammonium hydrogen phosphate to the crystalline boron phosphate is 1:3, and the metal salt solution is 1.8g of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 10-1.

Example 10-2

Same as the embodiment4-2, the difference is that the phosphorus source is diammonium hydrogen phosphate and crystalline boron phosphate, the weight ratio of the diammonium hydrogen phosphate to the crystalline boron phosphate is 1:3, and the metal salt solution is 1.8g of ferric nitrate. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 10-2.

The phosphorus dispersion K of GPMZ8-1, GPMZ8-2, GPMZ9-1, GPMZ9-2, GPMZ10-1, GPMZ10-2 is listed in Table 8-1.

GPMZ8-1, GPMZ8-2, GPMZ9-1, GPMZ9-2, GPMZ10-1 and GPMZ10-2 are subjected to hydrothermal aging treatment at 800 ℃ and 100% steam for 17h, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 8-2.

TABLE 8-1

TABLE 8-2

Example 11-1

Same as the embodiment8-1, with the difference that the phosphorus source is phosphoric acid and crystalline boron phosphate in a weight ratio of 3: 1. The obtained phosphorusAnd an iron modified multi-stage pore ZSM-5 molecular sieve sample, designated GPMZ 11-2.

Example 11-2

Same as the embodiment8-2, with the difference that the phosphorus source is phosphoric acid and crystalline boron phosphate in a weight ratio of 3: 1. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 11-2.

Example 12-1

Same as the embodiment9-1, the difference is that the phosphorus source is phosphoric acid and crystalline boron phosphate, and the weight ratio of the phosphoric acid to the crystalline boron phosphate is 2: 2. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 12-1.

Example 12-2

Same as the embodiment9-2, with the difference that the phosphorus source is phosphoric acid and crystalline boron phosphate in a weight ratio of 2: 2. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 12-2.

Example 13-1

Same as the embodiment10-1, with the difference that the phosphorus source is phosphoric acid and crystalline boron phosphate in a weight ratio of 1: 3. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 13-2.

Example 13-2

Same as the embodiment10-2, with the difference that the phosphorus source is phosphoric acid and crystalline boron phosphate in a weight ratio of 1: 3. The resulting phosphorus and iron modified multi-stage pore ZSM-5 molecular sieve sample was designated GPMZ 13-2.

The phosphorus dispersion K of GPMZ11-1, GPMZ11-2, GPMZ12-1, GPMZ12-2, GPMZ13-1, and GPMZ13-2 is listed in Table 9-1.

The n-tetradecane hydrocarbon cracking evaluation is carried out on GPMZ11-1, GPMZ11-2, GPMZ12-1, GPMZ12-2, GPMZ13-1 and GPMZ13-2 after the treatment of hydrothermal aging at 800 ℃ for 17h with 100% steam. The evaluation data are shown in Table 9-2.

TABLE 9-1

TABLE 9-2

As can be seen from the data in tables 1-9-2 above, the phosphorus and metal modified hierarchical pore ZSM-5 molecular sieves of the present invention have higher degrees of dispersion, i.e., the K value of the dispersion achieved by GPMZ8-2, sample example 8-2, which was modified with a dual phosphorus source of phosphoric acid and crystalline boron phosphate, was 87%; after the hydrothermal aging treatment of 800 ℃, 100% of water vapor and 17 hours, the GPMZ8-2 sample of the embodiment 8-2 also shows that the catalytic cracking activity of the n-tetradecane is excellent, and the conversion rate, the liquefied gas yield and the triene yield are all improved. The phosphorus and metal modified MFI structure molecular sieve of the invention has higher liquefied gas yield while increasing the yield of low-carbon olefin.

Examples 14-26 illustrate modified microporous ZSM-5 molecular sieves and methods of the invention.

Example 14-1

Taking 16.2g of diammonium hydrogen phosphate and 113g of HZSM-5 molecular sieve (provided by Qilu Branch of China petrochemical catalyst company, the relative crystallinity is 91.1 percent, the molar ratio of silicon oxide to aluminum oxide is 24.1, and Na₂O content 0.039 wt% and specific surface area 353m²Per g, the total pore volume is 0.177ml/g, the same applies hereinafter) and 60g of deionized water, the mixture is beaten, heated to 100 ℃ and kept for 2 hours, dried at 110 ℃ and treated for 0.5 hour at 550 ℃ in an air atmosphere to obtain a phosphorus-containing ZSM-5 molecular sieve sample. And dissolving 1.8g of ferric nitrate in 60g of deionized water again, mixing, soaking and drying the obtained ZSM-5 molecular sieve sample containing phosphorus by adopting a soaking method, and roasting the obtained sample at 550 ℃ for 2 hours to obtain a phosphorus and iron modified ZSM-5 molecular sieve sample which is marked as GPMZ 14-1.

Comparative example 14-1

The same as example 14-1 except that the HZSM-5 molecular sieve was impregnated with the aqueous solution containing phosphorus at 20 ℃ for 2 hours by the impregnation method. A comparative sample of the phosphorus and iron modified ZSM-5 molecular sieve was obtained and was designated D14-1.

Example 14-2

The same as example 14-1 except that the treatment was carried out at 550 ℃ in an air atmosphere of 500 ℃ and 50% water vapor atmosphere for 0.5 hour. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 14-2.

Comparative examples 14 to 2

The same as example 14-2, except that the HZSM-5 molecular sieve was impregnated with the aqueous solution containing phosphorus at 20 ℃ for 2 hours by the impregnation method. A comparative sample of phosphorus and iron modified ZSM-5 molecular sieve was obtained and was designated D14-2.

The phosphorus dispersity K of GPMZ14-1, D14-1, GPMZ14-2 and D14-2 is listed in Table 10-1.

GPMZ14-1, D14-1, GPMZ14-2 and D14-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation. Micro-reverse evaluation conditions: the molecular sieve loading is 2g, the raw oil is n-tetradecane, the oil inlet amount is 1.56g, the reaction temperature is 550 ℃, and the regeneration temperature is 600 ℃ (the same below).

The evaluation data are shown in Table 10-2.

TABLE 10-1

TABLE 10-2

Example 15-1

Mixing 16.2g of diammonium hydrogen phosphate, 113g of HZSM-5 molecular sieve and 120g of deionized water, beating into slurry, keeping the slurry at 70 ℃ for 2 hours, drying at 110 ℃, treating for 2 hours at 550 ℃ in an air atmosphere, dissolving 2.1g of cobalt nitrate in 60g of deionized water again, modifying by adopting a dipping method, mixing with the obtained ZSM-5 molecular sieve sample containing phosphorus, dipping and drying, roasting the obtained sample at 550 ℃ for 2 hours, and obtaining the ZSM-5 molecular sieve sample modified by phosphorus and cobalt, which is marked as GPMZ 15-1.

Comparative example 15-1

The same as in example 15-1 except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium hydrogen phosphate at 20 ℃ by the impregnation method. A comparative sample of the phosphorus and cobalt modified ZSM-5 molecular sieve was obtained and was designated D15-1.

Example 15-2

The same as example 15-1 except that the treatment was carried out at 550 ℃ in an air atmosphere of 600 ℃ and 30% in a water vapor atmosphere for 2 hours. The resulting phosphorus and cobalt modified ZSM-5 molecular sieve sample was designated GPMZ 15-2.

Comparative examples 15 to 2

The same as example 15-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium phosphate at 20 ℃ by an impregnation method. A comparative sample of phosphorus and cobalt modified ZSM-5 molecular sieve was obtained and was designated D15-2.

The phosphorus dispersity K of GPMZ15-1, D15-1, GPMZ15-2 and D15-2 is listed in Table 11-1.

GPMZ15-1, D15-1, GPMZ15-2 and D15-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 11-2.

TABLE 11-1

TABLE 11-2

Example 16-1

Dissolving 10.4g of phosphoric acid and 2.1g of nickel nitrate in 60g of deionized water, and stirring for 2 hours to obtain a water solution containing phosphorus and nickel nitrate; taking 113g of HZSM-5 molecular sieve; and respectively heating the aqueous solution containing phosphorus and nickel nitrate and the HZSM-5 molecular sieve to 80 ℃, mixing and contacting for 4 hours, drying at 110 ℃, and treating for 2 hours at 550 ℃ in an air atmosphere to obtain a phosphorus and nickel modified ZSM-5 molecular sieve sample, wherein the sample is marked as GPMZ 16-1.

Comparative example 16-1

The same as example 16-1, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of phosphoric acid and nickel nitrate at 20 ℃. A comparative sample of the phosphorus and nickel modified ZSM-5 molecular sieve was obtained and designated D16-1.

Example 16-2

The same as example 16-1, except that the treatment was carried out at 400 ℃ in an air atmosphere of 550 ℃ and 100% water vapor atmosphere for 2 hours. The resulting phosphorus and nickel modified ZSM-5 molecular sieve sample was designated GPMZ 16-2.

Comparative example 16-2

The same as example 16-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of phosphoric acid and nickel nitrate at 20 ℃. A comparative sample of phosphorus and nickel modified ZSM-5 molecular sieve was obtained and was designated D16-2.

The phosphorus dispersity K for GPMZ16-1, D16-1, GPMZ16-2 and D15-2 is listed in Table 12-1. GPMZ16-1, D16-1, GPMZ16-2 and D16-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 12-2.

TABLE 12-1

TABLE 12-2

Example 17-1

8.1g of diammonium hydrogen phosphate, 1.2 g of zinc sulfate, 113g of HZSM-5 molecular sieve and 120g of deionized water are mixed and beaten into slurry, the slurry is kept at 90 ℃ for 4 hours, the slurry is dried at 110 ℃ and treated at 550 ℃ for 2 hours in an air atmosphere, and a phosphorus and zinc modified ZSM-5 molecular sieve sample is obtained and is marked as GPMZ 17-1.

Comparative example 17-1

The same as example 17-1, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium hydrogen phosphate and zinc sulfate at 20 ℃ by the impregnation method. A comparative sample of the phosphorus and zinc modified ZSM-5 molecular sieve was obtained and designated D17-1.

Example 17-2

The same as example 17-1 except that the treatment was carried out at 550 ℃ in an air atmosphere of 300 ℃ and 100% water vapor atmosphere for 2 hours. The resulting phosphorus and zinc modified ZSM-5 molecular sieve sample was designated GPMZ 17-2.

Comparative examples 17 to 2

The same as example 17-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of diammonium hydrogen phosphate and zinc sulfate at 20 ℃ by the impregnation method. A comparative sample of phosphorus and zinc modified ZSM-5 molecular sieve was obtained and was designated D17-2.

The phosphorus dispersity K of GPMZ17-1, D17-1, GPMZ17-2 and D17-2 is listed in Table 13-1. GPMZ17-1, D17-1, GPMZ17-2 and D17-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 13-2.

TABLE 13-1

TABLE 13-2

Example 18-1

8.5g of trimethyl phosphate, 1.5 g of manganese nitrate, 113g of HZSM-5 molecular sieve and 80g of deionized water are mixed and beaten, heated to 120 ℃ and kept for 8 hours, dried at 110 ℃ and treated for 2 hours at 550 ℃ in an air atmosphere to obtain a phosphorus and manganese modified ZSM-5 molecular sieve sample which is marked as GPMZ 18-1.

Comparative example 18-1

The same as in example 18-1 except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of trimethyl phosphate and 1.5 g of manganese nitrate at 20 ℃ by the impregnation method. The comparative sample of phosphorus and manganese modified ZSM-5 molecular sieve obtained was designated D18-1.

Example 18-2

The same as example 18-1 except that the treatment was carried out at 550 ℃ in an air atmosphere of 500 ℃ and 80% water vapor atmosphere for 4 hours. The resulting phosphorus and manganese modified ZSM-5 molecular sieve sample was designated GPMZ 18-2.

Comparative example 18-2

The same as example 18-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of trimethyl phosphate and manganese nitrate at 20 ℃ by the impregnation method. A comparative sample of phosphorus and manganese modified ZSM-5 molecular sieve was obtained and was designated D18-2.

The phosphorus dispersity K of GPMZ18-1, D18-1, GPMZ18-2 and D18-2 is listed in Table 14-1.

GPMZ18-1, D18-1, GPMZ18-2 and D18-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 14-2.

TABLE 14-1

TABLE 14-2

Example 19-1

After 11.6g of boron phosphate, 2.0 g of gallium nitrate, 113g of HZSM-5 molecular sieve and 100g of deionized water are mixed and beaten into slurry, the slurry is kept at 150 ℃ for 2 hours, dried at 110 ℃ and treated at 550 ℃ for 2 hours in an air atmosphere, and an obtained phosphorus and gallium modified ZSM-5 molecular sieve sample is marked as GPMZ 19-1.

Comparative example 19-1

The same as example 19-1, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of boron phosphate and gallium nitrate at 20 ℃ by the impregnation method. The obtained phosphorus and gallium modified ZSM-5 molecular sieve comparative sample is marked as D19-1.

Example 19-2

The same as example 19-1, except that the treatment was carried out at 400 ℃ in an air atmosphere of 550 ℃ and 100% water vapor atmosphere for 4 hours. The resulting phosphorus and gallium modified ZSM-5 molecular sieve sample was designated GPMZ 19-2.

Comparative example 19-2

The same as example 19-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution of boron phosphate and gallium nitrate at 20 ℃ by the impregnation method. A comparative sample of phosphorus and gallium modified ZSM-5 molecular sieve was obtained and was designated D19-2.

The phosphorus dispersity K for GPMZ19-1, D19-1, GPMZ19-2 and D19-2 is listed in Table 15-1.

GPMZ19-1, D19-1, GPMZ19-2 and D19-2 are subjected to 100 percent steam at 800 ℃ and 17h hydrothermal aging treatment, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 15-2.

TABLE 15-1

TABLE 15-2

Example 20-1

Dissolving 14.2g of triphenyl phosphine and 2.0 g of stannic chloride in 80g of deionized water, and stirring for 2 hours to obtain aqueous solution containing phosphorus and stannic chloride; taking 113g of HZSM-5 molecular sieve; and respectively heating the phosphorus-containing aqueous solution and the HZSM-5 molecular sieve to 80 ℃, mixing and contacting for 4 hours, drying at 110 ℃, and treating for 2 hours at 550 ℃ in an air atmosphere to obtain phosphorus and tin modified ZSM-5 molecular sieve samples, wherein the samples are marked as GPMZ 20-1.

Comparative example 20-1

The same as example 20-1 except that the HZSM-5 molecular sieve was impregnated with an aqueous solution containing phosphorus and tin chloride at 20 ℃ by an impregnation method. A comparative sample of the phosphorus and tin modified ZSM-5 molecular sieve was obtained and was identified as D20-1.

Example 20-2

The same as example 20-1 except that the treatment was carried out at 550 ℃ in an air atmosphere of 600 ℃ and 30% water vapor atmosphere for 4 hours. The resulting phosphorus and tin modified ZSM-5 molecular sieve sample was designated GPMZ 20-2.

Comparative example 20-2

The same as example 20-2, except that the HZSM-5 molecular sieve was impregnated with an aqueous solution containing phosphorus and tin chloride at 20 ℃ by the impregnation method. A comparative sample of phosphorus and tin modified ZSM-5 molecular sieve was obtained and was designated D20-2.

The phosphorus dispersity K for GPMZ20-1, D20-1, GPMZ20-2 and D20-2 is listed in Table 16-1.

GPMZ20-1, D20-1, GPMZ20-2 and D20-2 are subjected to hydrothermal aging treatment at 800 ℃ for 17 hours with 100 percent of water vapor, and then subjected to n-tetradecane hydrocarbon cracking evaluation.

The evaluation data are shown in Table 16-2.

TABLE 16-1

TABLE 16-2

Example 21-1

The same as in example 17-1, except that the phosphorus source was diammonium phosphate and crystalline boron phosphate in a weight ratio of 3:1, and the metal salt solution was 1.8g of ferric nitrate. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 21-1.

Example 21-2

The same as in example 17-2, except that the phosphorus source was diammonium phosphate and crystalline boron phosphate in a weight ratio of 3:1, and the metal salt solution was 1.8g of ferric nitrate. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 21-2.

Example 22-1

The same as in example 17-1, except that the bisphosphine source was diammonium hydrogen phosphate and crystalline boron phosphate in a weight ratio of 2:2, and the metal salt solution was 1.8g of ferric nitrate, for example. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 22-1.

Example 22-2

The same as in example 17-2, except that the phosphorus source was diammonium phosphate and crystalline boron phosphate in a weight ratio of 2:2, and the metal salt solution was 1.8g of ferric nitrate. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 23-2.

Example 23-1

The same as in example 17-1, except that the phosphorus source was diammonium hydrogen phosphate and crystalline boron phosphate in a weight ratio of 1:3, and the metal salt solution was 1.8g of ferric nitrate. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 23-1.

Example 23-2

The same as in example 17-2, except that the phosphorus source was diammonium hydrogen phosphate and crystalline boron phosphate in a weight ratio of 1:3, and the metal salt solution was 1.8g of ferric nitrate. The resulting phosphorus and iron modified ZSM-5 molecular sieve sample was designated GPMZ 23-2.

The phosphorus dispersion K of GPMZ21-1, GPMZ21-2, GPMZ22-1, GPMZ22-2, GPMZ23-1, and GPMZ23-2 is listed in Table 17-1.

GPMZ8-1, GPMZ8-2, GPMZ9-1, GPMZ9-2, GPMZ10-1 and GPMZ10-2 are subjected to hydrothermal aging treatment at 800 ℃ and 100% steam for 17h, and then subjected to n-tetradecane hydrocarbon cracking evaluation. The evaluation data are shown in Table 17-2.

TABLE 17-1

TABLE 17-2

Example 24-1 to example 26-2

The phosphorus sources in examples 21-1 to 23-2 were replaced with phosphoric acid and crystalline boron phosphate in the respective ratios of 3:1, 2:2, 1:3 and 1:3 in this order, and the phosphorus dispersion degrees K of the obtained samples, GPMZ24-1, GPMZ24-2, GPMZ25-1, GPMZ25-2, GPMZ26-1 and GPMZ26-2, respectively, are shown in Table 18-1.

The n-tetradecane hydrocarbon cracking evaluation is carried out on GPMZ24-1, GPMZ24-2, GPMZ25-1, GPMZ25-2, GPMZ26-1 and GPMZ26-2 after the hydrothermal aging treatment at 800 ℃ and 100% steam for 17 h. The data are shown in Table 18-2.

TABLE 18-1

TABLE 18-2

As can be seen from the data in tables 10-1 to 18-2, the phosphorus modified ZSM-5 molecular sieves of the present invention have higher dispersion degree of phosphorus, especially the dispersion degree K value of the sample modified by the diphosphorus source of phosphoric acid and crystalline boron phosphate of example 21-2 is 82%, which is improved by 18% at most; the embodiment 21-2 also shows that the catalyst has excellent catalytic cracking activity of the n-tetradecane after the hydrothermal aging treatment of 800 ℃, 100% of water vapor and 17 hours, and the conversion rate, the liquefied gas yield and the triene yield are all improved. The phosphorus modified MFI structure molecular sieve of the invention has higher liquefied gas yield while increasing the yield of low-carbon olefin.

Example 27-1

The same as example 4-1 except that zinc sulfate was replaced with 3.3 g of lanthanum nitrate. The resulting phosphorus and lanthanum modified hierarchical pore ZSM-5 molecular sieve sample, designated GPMZ27-1

Example 27-2

The same as example 4-2 except that zinc sulfate was replaced with 3.3 g of lanthanum nitrate. The obtained phosphorus and lanthanum modified hierarchical pore ZSM-5 molecular sieve sample is marked as GPMZ27-2

Example 28-1

The same as example 17-1 except that the zinc sulfate was replaced with 1.8g of cerium chloride. The resulting phosphorus and cerium modified microporous ZSM-5 molecular sieve sample, designated GPMZ28-1

Example 28-2

The same as example 17-2 except that the zinc sulfate was replaced with 1.8g of cerium chloride. The obtained microporous ZSM-5 molecular sieve modified by phosphorus and cerium is marked as GPMZ28-2

Example 29-1

The same as in example 4-1 except that 1.2 g of zinc sulfate was replaced with 0.8 g of iron nitrate and 0.8 g of manganese nitrate. The obtained phosphorus, iron and manganese modified hierarchical pore ZSM-5 molecular sieve sample is marked as GPMZ29-1

Example 29-2

The same as in example 4-2 except that 1.2 g of zinc sulfate was replaced with 0.8 g of iron nitrate and 0.8 g of manganese nitrate. The obtained phosphorus, iron and manganese modified hierarchical pore ZSM-5 molecular sieve sample is marked as GPMZ29-2

Example 30-1

The same as in example 17-1 except that 1.2 g of zinc sulfate was replaced with 0.8 g of iron nitrate and 0.8 g of zinc sulfate. The resulting phosphorus, iron, and zinc modified microporous ZSM-5 molecular sieve sample, designated GPMZ30-1

Example 30-2

The same as in example 17-2 except that 1.2 g of zinc sulfate was replaced with 0.8 g of iron nitrate and 0.8 g of zinc sulfate. The resulting phosphorus, iron, and zinc modified microporous ZSM-5 molecular sieve sample, designated GPMZ30-2

The phosphorus dispersion K of GPMZ27-1, GPMZ27-2, GPMZ28-1, GPMZ28-2, GPMZ29-1, GPMZ29-2, GPMZ30-1, GPMZ30-2 is shown in Table 19-1, and n-tetradecane hydrocarbon cracking evaluation was performed after hydrothermal aging treatment at 800 ℃, 100% steam, 17 h. The data are shown in Table 19-2.

TABLE 19-1

TABLE 19-2

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A modified Si-Al molecular sieve with MFI structure contains P and metal, P is used as P₂O₅The molar ratio of the metal to the aluminum oxide is more than or equal to 0.01, and the metal accounts for 0.1-10 wt% of the oxide; the molecular sieve has a K value satisfying: k is more than or equal to 70% and less than or equal to 90%, and K is P1/P2 x 100%, wherein P1 represents the phosphorus content of the molecular sieve crystal grain measured by an XPS method in any crystal plane vertical depth of 0-2 nm and in a 100 square nanometer area, and P2 represents the phosphorus content of the molecular sieve crystal grain measured by an EPMA method in any crystal plane vertical depth of 5-10 nm in a thickness interval of 100 square nanometer area.

2. A molecular sieve according to claim 1 wherein said K value satisfies: k is more than or equal to 75% and less than or equal to 90%, and preferably, the K value satisfies the following condition: k is more than or equal to 78 percent and less than or equal to 85 percent.

3. A molecular sieve according to claim 1 wherein the phosphorus content is P₂O₅The molar ratio of the alumina to the alumina is not less than 0.2, preferably not less than 0.3, and more preferably 0.4 to 0.7.

4. The molecular sieve of claim 1 wherein said metal is selected from one or more of the group consisting of VIII, IIB, VIIB, IIIA, IVA, lanthanide metals.

5. A molecular sieve according to claim 4 wherein said metal is selected from one or more of Fe, Co, Ni, Zn, Mn, Ga, Sn, La, Ce.

6. A molecular sieve according to claim 1, 4 or 5 wherein the metal is present in an amount of from 0.1 to 10 wt%, preferably from 0.2 to 5 wt% calculated as oxide.

7. The molecular sieve of claim 1 wherein said MFI structure aluminosilicate molecular sieve is a microporous ZSM-5 molecular sieve or a multigraded pore ZSM-5 molecular sieve.

8. The molecular sieve of claim 7, wherein said microporous ZSM-5 molecular sieve has a silica/alumina mole ratio of 15 to 1000, preferably 20 to 200.

9. The method according to claim 7, wherein the hierarchical pore ZSM-5 molecular sieve has a mesopore volume accounting for more than 10% of the total pore volume, an average pore diameter of 2 to 20nm, and a silica/alumina molar ratio of 15 to 1000, preferably 20 to 200.

10. A process for the preparation of an MFI structure silicoaluminophosphate molecular sieve as claimed in any of claims 1 to 9, characterised in that:

mixing and contacting a phosphorus-containing compound aqueous solution with a temperature of 40-150 ℃, preferably 50-150 ℃, more preferably 70-130 ℃ with an MFI structure silicon-aluminum molecular sieve with a temperature of 40-150 ℃, preferably 50-150 ℃, more preferably 70-130 ℃ at substantially the same temperature for at least 0.1 hour by using an impregnation method, drying, roasting at 200-600 ℃ in an air or steam atmosphere for at least 0.1 hour to obtain a product, and impregnating and roasting the product by using a metal compound solution; or,

mixing and pulping a phosphorus-containing compound, an MFI structure silicon-aluminum molecular sieve and water, heating to 40-150 ℃, preferably 50-150 ℃, more preferably 70-130 ℃, keeping for at least 0.1 hour, drying, roasting at 200-600 ℃ in the air or steam atmosphere for at least 0.1 hour, and impregnating and roasting the product obtained by roasting at least 0.1 hour with a solution of a metal compound; or,

11. The process according to claim 10, wherein the phosphorus-containing compound is selected from organic phosphorus and/or inorganic phosphorus.

12. The process according to claim 11, wherein said organic phosphorus is selected from the group consisting of trimethyl phosphate, triphenyl phosphorus, trimethyl phosphite, tetrabutyl phosphonium bromide, tetrabutyl phosphonium chloride, tetrabutyl phosphonium hydroxide, triphenylethyl phosphonium bromide, triphenylbutyl phosphonium bromide, triphenylbenzyl phosphonium bromide, hexamethylphosphoric triamide, dibenzyl diethyl phosphorus, 1, 3-xylene bistriethyl phosphorus, and said inorganic phosphorus is selected from the group consisting of phosphoric acid, ammonium hydrogen phosphate, diammonium hydrogen phosphate, ammonium phosphate, boron phosphate.

13. The preparation method according to claim 10, wherein the molar ratio of the phosphorus-containing compound to the hydrogen-type ZSM-5 molecular sieve is 0.01-2; preferably, the molar ratio of the two is 0.1-1.5; more preferably, the molar ratio of the two is 0.2 to 1.5.

14. The process according to claim 10, wherein the phosphorus-containing compound is a mixture of boron phosphate and one or more selected from the group consisting of trimethyl phosphate, triphenyl phosphorus, trimethyl phosphite, phosphoric acid, ammonium hydrogen phosphate, diammonium hydrogen phosphate, and ammonium phosphate, and the mixture contains 10 to 80% by weight of boron phosphate, preferably 20 to 40% by weight of boron phosphate.

15. The process according to claim 10, wherein the contacting is carried out for 0.5 to 40 hours with a water-sieve weight ratio of 0.5 to 1.

16. The method according to claim 10, wherein the calcination is carried out at 450 to 550 ℃ in an air atmosphere.

17. The process according to claim 10, wherein the metal compound is a water-soluble salt of one or more metals selected from the group consisting of VIII, IIB, VIIB, IIIA, IVA and lanthanides.

18. The method of claim 17, wherein the water-soluble salt is selected from the group consisting of sulfate, nitrate, and chloride.

19. The method according to claim 18, wherein the water-soluble salt is selected from the group consisting of iron nitrate, cobalt nitrate, nickel nitrate, manganese nitrate, potassium nitrate, zinc sulfate, tin chloride, lanthanum nitrate, and cerium chloride.