CN116037196A

CN116037196A - Super-stable modified Y-type molecular sieve containing phosphorus and preparation method thereof

Info

Publication number: CN116037196A
Application number: CN202111263040.1A
Authority: CN
Inventors: 周灵萍; 严加松; 卢冠群; 王宇飞; 沙昊; 宋海涛; 张蔚琳; 袁帅
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: 2021-10-28
Filing date: 2021-10-28
Publication date: 2023-05-02

Abstract

The invention provides a phosphorus-modified ultrastable modified Y-type molecular sieve and a preparation method thereof, wherein the phosphorus-modified ultrastable modified Y-type molecular sieve comprises 1 to 10 weight percent of rare earth oxide, 0.05 to 6 weight percent of phosphorus and 0.05 to 0.5 weight percent of sodium oxide based on the dry weight of the molecular sieve, and the skeleton silicon-aluminum ratio of the modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36, the total pore volume is 0.35-0.45 mL/g, the unit cell constant is 2.428-2.450 nm, the lattice collapse temperature is not lower than 1070 ℃, the relative crystallinity is 60-80%, and the specific surface area is not lower than 645m ² And/g. The preparation method comprises the steps of contacting a NaY molecular sieve with NaY mother liquor, adding a dilute acid solution, and mixing until uniformity; carrying out ion exchange reaction; performing mild hydrothermal superstable modification treatment; phosphorus modification and fourAnd (3) a step of contact reaction of the silicon chloride gas. The preparation method not only can improve the crystallinity and heavy oil conversion capability of the ultra-stable Y-type molecular sieve, but also can improve the recycling rate of Si in NaY mother liquor, reduce the production cost and reduce the discharge of wastewater and waste residues.

Description

Super-stable modified Y-type molecular sieve containing phosphorus and preparation method thereof

Technical Field

The invention relates to a phosphorus-containing ultrastable modified Y-type molecular sieve and a preparation method thereof.

Background

Y-type molecular sieves (also known as Y-type zeolites) have been the primary active component of heavy oil catalytic cracking since the first use in the 60 s of the last century. Therefore, how to improve the crystallinity and stability of the modified Y-type molecular sieve, and further improve the activity and stability of the catalytic cracking catalyst is a goal pursued by catalyst manufacturers.

In addition, as environmental requirements become increasingly stringent, the waste water and waste residue discharge of catalyst manufacturers has become an important factor in limiting their development and even affecting their normal production.

At present, when the NaY molecular sieve is industrially synthesized, the ratio of the fed silicon to the aluminum is generally 7.5-10, and the ratio of the product silicon to the aluminum is generally 4.5-5.5, so that a large amount of silicon is not utilized in the synthesis mother liquor, and the primary utilization rate of the silicon is low, generally only about 60% -70%. That is, 30 to 40 percent of SiO is still remained ₂ Is present in the mother liquor. If such NaY mother liquor is discharged directly into the sewage treatment tank without treatment, a large amount of free SiO therein ₂ Is easy to react with other sewage to form colloid, and is settled subsequentlyIt is very difficult. When the plate frame filter filters, colloid adheres to the surface of the filter cloth, influences the permeability of the filter cloth, increases the sewage treatment difficulty, is extremely easy to cause the overstandard of suspended matters of external sewage discharge, and meanwhile, the filter cloth is frequently replaced, so that the sewage treatment cost is high. After 2006, catalyst manufacturers recycled NaY mother liquor, but the recovery amount was limited due to technical reasons. Along with the increase of the catalyst demand and the productivity, the production capacity of NaY molecular sieves is gradually expanded, naY synthesis large-scale devices are used, the annual output of the domestic Y molecular sieves at present is over 10 ten thousand tons, and the generated NaY mother liquor volume is also greatly increased. The recovery treatment of NaY mother liquor has seriously affected the standard discharge of the discharged sewage. Therefore, how to improve the recovery and utilization rate of NaY mother liquor, reduce the discharge pollution of waste water and waste residue and reduce the production cost is a double requirement of production and environmental protection.

At present, a method for forming silicon-aluminum hydrogel is mainly adopted in industrial NaY production to recycle silicon in mother liquor. However, the main disadvantages of this approach are: (1) The NaY mother liquor produced in actual industry inevitably contains part of microcrystals of P-type hetero-crystals, so that the proportion of the recovered silicon source is limited to a certain extent in order to avoid the adverse effect of the P-type crystal seeds in the recovered silicon-aluminum gel on a synthesis system, and the silicon utilization rate is only about 75%, so that the silicon in the mother liquor cannot be completely recovered; (2) When the recovered solid-phase silica-alumina gel and the liquid-phase silica-alumina source are mixed in a raw material tank to prepare synthetic gel, the uniformity of the gel system composition is difficult to achieve, the generation of P-type hetero-crystals is easy to induce in the crystallization process, and the production process of NaY synthesis is unstable; (3) The reduction of the average particle size of NaY molecular sieves synthesized on the basis of partially recovered silica-alumina gel results in a decrease in the quality of the product, possibly adversely affecting the hydrothermal stability during subsequent use.

Therefore, in the prior art, the recovery of the NaY mother liquor and the direct use thereof in the synthesis of NaY are limited, the recovery rate of Si can reach 75% at most, and the silicon in the NaY mother liquor still cannot be completely recovered, so that the subsequent filter residue is difficult to landfill.

How to recycle Si in the NaY mother liquor further improves the recycling rate of Si in the NaY mother liquor, further reduces the cost and reduces the emission, protects the environment, and is an important technology which is urgently needed to be developed by catalyst production enterprises.

On the other hand, the hydrothermal ultrastable method is one of the most widely used modification methods of Y-type molecular sieves in industry, and is to exchange NaY zeolite with an aqueous solution of ammonium ions to reduce the sodium ion content in zeolite, and then bake the ammonium ion exchanged zeolite at 500-800 ℃ in a water vapor atmosphere to ultrastable it. The method has low cost and is easy for industrialized mass production, but has the defect of serious loss of crystallinity of the ultra-stable Y-type molecular sieve. The reason is that the super-stabilization process of the hydrothermal super-stabilization method is to utilize water molecules to attack aluminum atoms on the molecular sieve framework at high temperature, so that the aluminum atoms are removed from the molecular sieve framework to generate Al (OH) ₃ Al atoms on the framework are removed, al vacancies are left, then free Si in the molecular sieve migrates to the Al vacancies and fills the vacancies, so that the dealumination and silicon supplementing process is completed, the framework structure is completed, the framework silicon-aluminum ratio is improved, and the molecular sieve structure is ultra-stable. However, the problem of industrial hydrothermal ultrastable is that the aluminum on the framework is removed by steam to generate gaps, the silicon source near the aluminum of the molecular sieve framework is less, the dealumination speed of the molecular sieve is far higher than the migration speed of silicon, and the silicon cannot migrate into the gaps generated by dealumination in time, so that the lattice collapse of the molecular sieve at the gaps generated by dealumination is caused, and the crystallinity of the molecular sieve is lost. In general, for a hydrothermal ultrastable molecular sieve with high silicon-aluminum ratio, the dealumination amount is large and the speed is high, so that the migration amount and migration speed of silicon are insufficient, silicon cannot be timely fed into vacancies formed by dealumination, the crystallinity of the molecular sieve is lost, and the production of the hydrothermal ultrastable molecular sieve with high crystallinity and high silicon-aluminum ratio is difficult.

In summary, the prior art is difficult to realize higher reuse rate of Si in NaY mother liquor, and the existing hydrothermal ultrastable technology is difficult to prepare the hydrothermal ultrastable Y-type molecular sieve with small unit cells, high in framework silicon-aluminum ratio and high in crystallinity.

Disclosure of Invention

Aiming at the serious defects existing in the recycling of NaY synthesis mother liquor and the hydrothermal ultrastable process in the industrial molecular sieve production, the first technical problem to be solved by the invention is to provide the phosphorus-containing ultrastable modified Y-type molecular sieve with high framework silicon-aluminum ratio and high crystallinity. The second technical problem to be solved by the invention is to provide a method for preparing the ultrastable phosphorus modified Y-type molecular sieve, which can not only recycle the residual Si source in the NaY mother liquor to the greatest extent, thereby reducing the cost and the emission and protecting the environment; but also can overcome the defects of the existing hydrothermal ultrastable technology and can prepare the phosphorus-containing ultrastable modified Y-type molecular sieve with high skeleton silicon-aluminum ratio and high crystallinity.

In order to solve the technical problems, in one aspect, the invention provides a modified Y-type molecular sieve containing phosphorus, wherein the modified Y-type molecular sieve contains 1 to 10 weight percent of RE based on the total weight of the dry basis of the modified Y-type molecular sieve containing phosphorus ₂ O ₃ 0.05 to 6 weight percent of rare earth oxide calculated as P ₂ O ₅ Phosphorus and 0.05 to 0.5 weight percent of sodium oxide, wherein the skeleton silicon-aluminum ratio of the phosphorus-containing modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36; the unit cell constant of the modified Y-type molecular sieve containing phosphorus is 2.428 nm-2.450 nm; the total pore volume of the modified Y-type molecular sieve containing phosphorus is 0.35 mL/g-0.45 mL/g; the lattice collapse temperature of the phosphorus-containing modified Y-type molecular sieve is not lower than 1070 ℃; the relative crystallinity of the modified Y-type molecular sieve containing phosphorus is not less than 60%; the specific surface area of the modified Y-type molecular sieve containing phosphorus is not less than 645m ² /g。

In one embodiment, the phosphorus-containing modified Y-type molecular sieve contains 1 to 9 weight percent of RE ₂ O ₃ The rare earth oxide is calculated.

In one embodiment, the phosphorus-containing modified Y-type molecular sieve contains 0.5 to 4 weight percent of the catalyst selected from the group consisting of a catalyst and a catalyst ₂ O ₅ Phosphorus in a meter.

In one embodiment, the modified Y-type molecular sieve containing phosphorus contains 0.08 to 0.5 wt% sodium oxide.

In one embodiment, the framework silica to alumina ratio of the phosphorus-containing modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is 9.5-34.

In one embodiment, the modified Y-type molecular sieve containing phosphorus has a unit cell constant of 2.429nm to 2.448nm.

In one embodiment, the total pore volume of the phosphorus-containing modified Y-type molecular sieve is from 0.36 to 0.43mL/g;

in one embodiment, the modified Y-type molecular sieve containing phosphorus has a lattice collapse temperature of 1070 ℃ to 1095 ℃.

In one embodiment, the phosphorus-containing modified Y-type molecular sieve has a relative crystallinity of 60% to 80%, preferably 65% to 75%.

In one embodiment, the specific surface area of the modified Y-type molecular sieve containing phosphorus is not less than 645m ² Preferably 650-680 m ² /g。

In one embodiment, the modified Y-type molecular sieve containing phosphorus has a relative crystal retention of 45% or more, preferably 46 to 54% after aging at 800 ℃ under normal pressure in a 100% water vapor atmosphere for 17 hours.

The modified Y-type molecular sieve containing phosphorus provided by the invention has the advantages of high silicon-aluminum ratio of a framework, high crystallinity, high thermal and hydrothermal stability and high catalytic activity.

In one embodiment, the invention provides the use of the modified Y-type molecular sieve containing phosphorus for the catalytic cracking of heavy oils.

In another embodiment, the invention provides the use of the modified Y-type molecular sieve containing phosphorus for heavy oil hydrocracking.

In one embodiment, the invention provides a phosphorus-containing modified Y-type molecular sieve for heavy oil catalytic cracking, wherein the rare earth oxide content of the phosphorus-containing modified Y-type molecular sieve is RE based on the total weight of dry basis ₂ O ₃ 4 to 10 wt%, preferably 4.5 to 9 wt%; with P ₂ O ₅ The phosphorus content is 0.05 to 6 wt%, preferably 0.5 to 4 wt%; sodium oxide content is 0.1-0.5 wt%; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-19, preferably 9.5-18; the total pore volume is 0.35mL/g to 0.40mL/g, preferably 0.36mL/g to 0.39mL/g; the unit cell constant is 2.435 nm-2.450 nm, preferably 2.436 nm-2.448 nm; the lattice collapse temperature is not lower than 1070 ℃, preferably 1070-1080 ℃; specific surface area of 645m ² /g～670m ² /g, preferably 650m ² /g～665m ² /g; the relative crystallinity is 60 to 80 percent; preferably 65% to 75%.

In one embodiment, the invention provides a phosphorus-containing modified Y-type molecular sieve for heavy oil hydrocracking, wherein the rare earth oxide content of the phosphorus-containing modified Y-type molecular sieve is RE based on the total weight of dry basis ₂ O ₃ 1 to 4 weight percent, based on P ₂ O ₅ The calculated phosphorus content is 0.05 to 6 weight percent, the sodium oxide content is less than or equal to 0.25 weight percent, and the framework silicon aluminum ratio is SiO ₂ /Al ₂ O ₃ The molar ratio is 20-36, the total pore volume is 0.39-0.43 mL/g, the unit cell constant is 2.428-2.434 nm, the lattice collapse temperature is not lower than 1090 ℃, and the specific surface area is not lower than 670m ² And/g, the relative crystallinity is not less than 65%.

In another aspect, the present invention provides a method of preparing a modified Y-type molecular sieve comprising phosphorus, comprising the steps of:

(1) Contacting NaY molecular sieve with NaY mother liquor, adding dilute acid solution, mixing to uniformity, and filtering;

(2) Contacting the NaY molecular sieve obtained in the step (1) with a rare earth salt solution for ion exchange reaction, filtering, washing, and optionally drying to obtain a Y-type molecular sieve with reduced sodium oxide content;

(3) Performing mild hydrothermal ultrastable modification treatment on the Y-type molecular sieve with reduced sodium oxide content obtained in the step (2) to obtain the Y-type molecular sieve with reduced unit cell constant;

(4) Carrying out phosphorus modification treatment on the Y-type molecular sieve with the reduced unit cell constant obtained in the step (3) by using a phosphorus compound, and drying to obtain the Y-type molecular sieve with the reduced unit cell constant containing phosphorus;

(5) And (3) contacting the Y-type molecular sieve with the reduced unit cell constant of the phosphorus obtained in the step (4) with silicon tetrachloride gas for reaction, and optionally washing and optionally filtering to obtain the modified Y-type molecular sieve containing the phosphorus.

In one embodiment, in the step (1), the dilute acid is dilute hydrochloric acid, dilute sulfuric acid, or dilute nitric acid.

In one embodiment, the dilute acid solution is at a concentration of H in solution ⁺ The molar concentration of (C) is 0.001 to 0.1mol/L, preferably 0.005 to 0.05mol/L.

In one embodiment, the dilute acid solution is an aqueous solution of dilute acid.

In one embodiment, in the step (1), the NaY molecular sieve is contacted with the NaY mother liquor while stirring, the mixed slurry is heated to 40 to 90 ℃, preferably 50 to 75 ℃, and the diluted acid aqueous solution is added, followed by continuous stirring for 20 to 90 minutes, preferably 30 to 60 minutes, and then filtration.

In one embodiment, in said step (1), said NaY molecular sieve is a commercially available NaY molecular sieve or is a NaY molecular sieve filter cake that has been filtered and washed with industrial water after synthesis of the NaY molecular sieve; and/or the NaY mother liquor is the NaY mother liquor which is discharged after the NaY molecular sieve is synthesized, the solid NaY molecular sieve is filtered and separated from the NaY synthetic slurry, and the mother liquor which is remained after the NaY molecular sieve is not recycled in the NaY molecular sieve synthesis process.

In one embodiment, in step (2), the molecular sieve is prepared according to NaY: rare earth salt: h ₂ O=1: 0.01 to 0.18: 5-15 weight ratio of NaY molecular sieve, rare earth salt and water to form a mixture, and stirring to perform ion exchange reaction, wherein the weight of NaY molecular sieve is calculated on a dry basis, and the weight of rare earth salt is calculated on rare earth oxide. In a further embodiment, forming the NaY molecular sieve, the rare earth salt, and water into a mixture is accomplished by mixing the NaY molecular sieve with water, adding the rare earth salt and/or rare earth salt solution with stirring.

In one embodiment, in the step (2), the rare earth salt solution is an aqueous solution of a rare earth salt.

In one embodiment, in the step (2), the rare earth salt is rare earth chloride and/or rare earth nitrate.

In one embodiment, in the step (2), the conditions of the ion exchange reaction are: the exchange temperature is 15-95 ℃, preferably 65-95 ℃, and the exchange time is 30-120 minutes, preferably 45-90 minutes.

In one embodiment, in the step (3), the Y-type molecular sieve having a reduced sodium oxide content obtained in the step (2) is calcined at a temperature of 350 to 550 ℃, preferably 380 to 540 ℃, and 30 to 95% by volume, preferably 40 to 90% by volume, of a steam atmosphere for 4.5 to 8 hours, preferably 5 to 7 hours.

In one embodiment, in the step (4), the Y-type molecular sieve with reduced unit cell constant obtained in the step (3) is contacted with an exchange liquid containing a phosphorus compound and water, and is subjected to an exchange reaction at 15 to 100 ℃, preferably 30 to 95 ℃ for 10 to 100 minutes to carry out a phosphorus modification treatment; wherein the weight ratio of water in the exchange liquid to the Y-type molecular sieve with reduced unit cell constant on a dry basis is 2-5: 1, preferably 3 to 4:1, a step of; with P ₂ O ₅ The weight ratio of phosphorus to the Y-type molecular sieve with reduced unit cell constant on a dry basis is 0.0005 to 0.07:1, preferably 0.001 to 0.05:1.

in one embodiment, in the step (4), the phosphorus compound is selected from one or more of phosphoric acid, ammonium phosphate, monoammonium phosphate, diammonium phosphate.

In one embodiment, in step (4), the water content in the Y-type molecular sieve having a reduced unit cell constant of phosphorus is no more than 1 wt%.

In one embodiment, in said step (5), siCl ₄ : weight ratio of the Y-type molecular sieve with reduced unit cell constant of phosphorus on a dry basis=0.1 to 0.85:1, preferably 0.2 to 0.8:1, a step of; the reaction temperature is 200-620 ℃, preferably 250-600 ℃; the reaction time is 10 minutes to 5 hours, preferably 30 minutes to 4 hours.

The method for preparing the modified Y-type molecular sieve containing phosphorus can further utilize the silicon source in the NaY mother liquor which cannot be recycled in the NaY molecular sieve synthesis process and is discharged, so that the total recycling rate of Si in the NaY mother liquor is improved, the cost is reduced, the emission is reduced, and the environment is protected; meanwhile, the modified Y-type molecular sieve containing phosphorus with high skeleton silicon-aluminum ratio, high crystallinity, high thermal stability and high hydrothermal stability can be prepared.

In a further aspect, the present invention provides a modified Y-type molecular sieve containing phosphorus prepared according to the method of the present invention, which contains 1 to 10 wt%, preferably 1 to 9 wt% of RE, based on the total weight of the dry basis thereof ₂ O ₃ 0.05 to 6 wt%, preferably 0.5 to 4 wt% of rare earth oxide, based on P ₂ O ₅ 0.05 to 0.5 weight percent of sodium oxide calculated by phosphorus, wherein the skeleton silicon-aluminum ratio of the phosphorus-containing modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36, preferably 9.5-34; the unit cell constant of the modified Y-type molecular sieve containing phosphorus is 2.428 nm-2.450 nm, preferably 2.429 nm-2.448 nm; the total pore volume of the modified Y-type molecular sieve containing phosphorus is 0.35-0.45 mL/g, preferably 0.36-0.43 mL/g; the lattice collapse temperature of the phosphorus-containing modified Y-type molecular sieve is not lower than 1070 ℃, and is preferably 1070-1095 ℃; the relative crystallinity of the modified Y-type molecular sieve containing phosphorus is not less than 60%, preferably 60-80%, more preferably 65-75%; the specific surface area of the modified Y-type molecular sieve containing phosphorus is not less than 645m ² Preferably 650-680 m ² /g。

In one embodiment, the phosphorus-containing modified Y-type molecular sieve prepared according to the method of the present invention has a relative crystal retention of 45% or more, preferably 46 to 54% after aging at 800℃under normal pressure in a 100% steam atmosphere for 17 hours.

The modified Y-type molecular sieve containing phosphorus prepared by the method has high framework silicon-aluminum ratio, high crystallinity, high thermal stability and high hydrothermal stability, and the aluminum in the molecular sieve is uniformly distributed, and the non-framework aluminum content is low.

The modified Y-type molecular sieve containing phosphorus can be used as an active component of a catalytic cracking catalyst and used for converting heavy oil or inferior oil; when the catalytic cracking catalyst taking the molecular sieve as an active component is used for heavy oil conversion, the catalytic cracking catalyst has strong heavy oil conversion capability, high stability, high liquefied gas yield, light oil yield, gasoline yield and total liquid yield, and good coke selectivity.

The modified Y-type molecular sieve containing phosphorus can also be used as an acidic component in a hydrocracking catalyst and used for hydrocracking heavy oil; the hydrocracking catalyst taking the molecular sieve as an acidic component has higher hydrogenation activity (toluene conversion rate) and hydrocracking activity (n-decane conversion rate).

Detailed Description

In the present invention, the weight of the various molecular sieves involved, whether or not explicitly mentioned, is on a dry basis; the weight or the content of the rare earth salt and the rare earth are calculated by the weight or the content of the oxidized rare earth; the weight or content of the phosphorus is that of phosphorus pentoxide (P ₂ O ₅ ) Weight or content meter of (a); the weight or content of sodium is calculated by the weight or content of sodium oxide; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ Molar ratio meter; the water vapor is calculated by volume ratio.

In the invention, "heavy oil" refers to the residual heavy oil after the crude oil is used for extracting gasoline and diesel oil, and is characterized by large molecular weight and high viscosity. Examples of heavy oils include, but are not limited to, one or more of atmospheric wax oil, vacuum wax oil, coker wax oil, atmospheric residuum, vacuum residuum, heavy Cycle Oil (HCO).

In the present invention, "catalytic cracking" is one of petroleum refining processes, which is a process of converting heavy oil into cracked gas, gasoline, diesel oil, etc. by cracking reaction under the action of heat and catalyst.

In the present invention, "hydrocracking" is one of petroleum refining processes, which is a process of converting heavy oil into gas, gasoline, jet fuel, diesel oil, etc. by cracking reaction under the conditions of heating, high hydrogen pressure and the presence of a catalyst.

In the present invention, the term "mild hydrothermal ultrastable treatment" means a vapor dealumination and silicon repair process performed under mild conditions of a vapor atmosphere of 30 to 95% by volume at a temperature of 350 to 550 ℃.

The invention provides a modified Y-type molecular sieve containing phosphorus, which is prepared from the modified Y-type molecular sieve The modified Y-type molecular sieve containing phosphorus contains RE accounting for 1 to 10 weight percent based on the total weight of the dry basis ₂ O ₃ 0.05 to 6 weight percent of rare earth oxide calculated as P ₂ O ₅ 0.05 to 0.5 weight percent of sodium oxide based on phosphorus; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36; the unit cell constant is 2.428 nm-2.450 nm; the total pore volume is 0.35 mL/g-0.45 mL/g; the lattice collapse temperature is not lower than 1070 ℃; the relative crystallinity is not less than 60%; specific surface area of not less than 645m ² /g。

In one embodiment, the phosphorus-containing modified Y-type molecular sieve has a rare earth oxide content of RE ₂ O ₃ It is 1 to 10 wt%, preferably 1 to 9 wt%, for example 1.3 wt%, 4.8 wt%, 5.4 wt% or 7.3 wt%.

In one embodiment, the rare earth in the phosphorus-containing modified Y-type molecular sieve may be selected from one or more of La, ce, pr, nd and mischmetal, for example. In one embodiment, the misch metal may contain one or more of La, ce, pr, and Nd, or may further contain at least one of rare earths other than La, ce, pr, and Nd.

In one embodiment, the phosphorus content of the phosphorus-containing modified Y-type molecular sieve is defined as P ₂ O ₅ It is preferably 0.05 to 6 wt%, for example 0.84 wt%, 0.87 wt%, 1.95 wt% or 2.56 wt%, based on the total weight of the composition.

In one embodiment, the sodium oxide content of the phosphorus-containing modified Y-type molecular sieve is from 0.05 wt% to 0.5 wt%, preferably from 0.08 wt% to 0.5 wt%, for example, from 0.09 wt%, 0.39 wt%, 0.43 wt%, or 0.47 wt%.

In one embodiment, the framework silica to alumina ratio of the phosphorus-containing modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is from 8.8 to 36, preferably from 9.5 to 34, more preferably from 10 to 33, for example from 11.39, 13.95, 16.63 or 31.68.

In one embodiment, the modified Y-type molecular sieve containing phosphorus has a unit cell constant of 2.428nm to 2.450nm, preferably 2.429nm to 2.448nm, for example 2.429nm, 2.437nm, 2.440nm or 2.444nm.

In one embodiment, the modified Y molecular sieve containing phosphorus has a total pore volume of 0.35mL/g to 0.45mL/g, preferably 0.36 to 0.43mL/g, such as 0.365mL/g, 0.369mL/g, 0.377mL/g, or 0.408mL/g.

In one embodiment, the modified Y-type molecular sieve containing phosphorus has a lattice collapse temperature of not less than 1070 ℃, preferably 1070 ℃ to 1095 ℃, such as 1074 ℃, 1076 ℃, 1079 ℃ or 1092 ℃, indicating a higher thermal stability.

In one embodiment, the phosphorus-containing modified Y-type molecular sieve has a relative crystallinity of not less than 60%, preferably 60% to 80%, more preferably 65% to 75%, for example 66.2%, 68.1%, 69.1% or 70.2%, indicating a higher crystallinity.

In one embodiment, the specific surface area of the modified Y-type molecular sieve containing phosphorus is not less than 645m ² Preferably 650-680 m ² /g, e.g. 653m ² /g、655m ² /g、662m ² /g or 671m ² /g。

In one embodiment, the phosphorus-containing modified Y-type molecular sieve contains 1 to 9 wt% of RE based on the dry basis weight thereof ₂ O ₃ 0.5 to 4 weight percent of rare earth oxide calculated as P ₂ O ₅ 0.08 to 0.5 weight percent of sodium oxide based on phosphorus; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 9.5-34; the unit cell constant is 2.429 nm-2.448 nm; the total pore volume is 0.36 mL/g-0.43 mL/g; the temperature of lattice collapse is 1070-1095 ℃; the relative crystallinity is 60-80%, more preferably 65-75%; the specific surface area is 650-680 m ² /g。

In one embodiment, the phosphorus-containing modified Y-type molecular sieve has a relative crystal retention of 45% or more, preferably 46 to 54%, such as 48.72%, 48.90%, 49.40% or 51.37%, after aging at 800℃for 17 hours under an atmospheric pressure, 100% steam atmosphere, indicating a higher hydrothermal stability. In the present invention, the reference to "normal pressure" means 1atm.

The modified Y-type molecular sieve containing phosphorus has high silicon-aluminum ratio of a framework, high crystallinity, high thermal and hydrothermal stability and high catalytic activity.

In one embodiment, the modified Y-type molecular sieve containing phosphorus of the invention can be used for heavy oil catalytic cracking, has higher heavy oil conversion activity and better coke selectivity than the existing Y-type molecular sieve, and has higher liquefied gas yield, gasoline yield, light oil yield and total liquid yield.

In one embodiment, the modified Y-type molecular sieve of the present invention can be used for hydrocracking, and has higher hydrogenation activity (toluene conversion) and hydrocracking activity (n-decane conversion) than the existing Y-type molecular sieve.

In one embodiment, the present invention provides a modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, wherein the modified Y-type molecular sieve containing 4 to 10 weight percent of RE based on the total weight of the dry basis ₂ O ₃ 0.05 to 6 weight percent of rare earth oxide calculated as P ₂ O ₅ Phosphorus accounting for 0.1 to 0.5 weight percent of sodium oxide and the Si/Al ratio of the framework is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-19; the unit cell constant is 2.435 nm-2.450 nm; the total pore volume is 0.35 mL/g-0.40 mL/g; the lattice collapse temperature is not lower than 1070 ℃; the relative crystallinity is 60 to 80 percent; specific surface area of 645-670 m ² /g。

In one embodiment, the rare earth oxide content of the phosphorus-containing modified Y-type molecular sieve for heavy oil catalytic cracking is RE ₂ O ₃ In the range of 4 to 10 wt.%, preferably 4.5 to 9 wt.%, for example 4.8 wt.%, 5.4 wt.%, or 7.3 wt.%.

In one embodiment, the rare earth in the modified Y-type molecular sieve containing phosphorus for catalytic cracking of heavy oil may be selected from, for example, one or more of La, ce, pr, nd and mischmetal. In one embodiment, the misch metal may contain one or more of La, ce, pr, and Nd, or may further contain at least one of rare earths other than La, ce, pr, and Nd.

In one embodiment, the phosphorus content of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is P ₂ O ₅ From 0.05 to 6% by weight, preferably from 0.5 to 4% by weight, for example from 0.87% by weight, 1.95% by weight or 2.56% by weight.

In one embodiment, the content of sodium oxide in the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is 0.1 wt% to 0.5 wt%, preferably 0.2 wt% to 0.5 wt%, for example, 0.39 wt%, 0.43 wt% or 0.47 wt%.

In one embodiment, the framework silica to alumina ratio of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is calculated as SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8 to 19, preferably 9.5 to 18, still preferably 10 to 17.7, more preferably 11 to 17, for example 11.39, 13.95 or 16.63.

In one embodiment, the unit cell constant of the modified Y-type molecular sieve containing phosphorus for catalytic cracking of heavy oil is from 2.435nm to 2.450nm, preferably from 2.436nm to 2.448nm, for example 2.437nm, 2.440nm or 2.444nm.

In one embodiment, the total pore volume of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is from 0.35mL/g to 0.40mL/g, preferably from 0.36 to 0.39mL/g, for example, 0.365mL/g, 0.369mL/g, or 0.377mL/g.

In one embodiment, the lattice collapse temperature of the modified Y-type molecular sieve containing phosphorus for catalytic cracking of heavy oil is not lower than 1070 ℃, preferably 1070 ℃ to 1080 ℃, such as 1074 ℃, 1076 ℃ or 1079 ℃, which indicates higher thermal stability.

In one embodiment, the relative crystallinity of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is 60% to 80%, preferably 65% to 75%, such as 66.2%, 68.1% or 70.2%, indicating a higher crystallinity.

In one embodiment, theThe specific surface area of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking is 645m ² /g～670m ² /g, preferably 650m ² /g～665m ² /g, e.g. 653m ² /g、655m ² /g or 662m ² /g。

In one embodiment, the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking contains 4.5 to 9 wt% of RE based on the dry weight of the molecular sieve ₂ O ₃ 0.5 to 4 weight percent of rare earth oxide calculated as P ₂ O ₅ Phosphorus accounting for 0.1 to 0.5 weight percent of sodium oxide and the Si/Al ratio of the framework is SiO ₂ /Al ₂ O ₃ The molar ratio is 9.5-18; the unit cell constant is 2.436 nm-2.448 nm; the total pore volume is 0.36-0.39 mL/g; the lattice collapse temperature is 1070-1080 ℃; the relative crystallinity is 65-75 percent; specific surface area of 650m ² /g～665m ² /g。

In one embodiment, the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking has a relative crystalline retention of 45% or more, preferably 46 to 52%, such as 48.72%, 48.90% or 49.40%, after aging at 800 ℃ for 17 hours under an atmosphere of 100% water vapor, indicating a higher hydrothermal stability.

In one embodiment, the invention provides a modified Y-type molecular sieve containing phosphorus for hydrocracking heavy oil, which has rare earth oxide content of RE based on the total weight of dry basis ₂ O ₃ From 1 to 4 wt%, for example 1.3 wt%; with P ₂ O ₅ The phosphorus content is 0.05 to 6 wt%, for example 0.84 wt%; sodium oxide content is 0.25 wt.%, for example 0.09 wt.%; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 20 to 36, for example 31.68; the total pore volume is 0.39mL/g to 0.43mL/g, for example 0.408mL/g; the unit cell constant is 2.428nm to 2.434nm, for example 2.429nm; the lattice collapse temperature is not lower than 1090 ℃, for example, 1092 ℃; specific surface area of not less than 670m ² /g, e.g. 671m ² /g; the relative crystallinity is not less than 65%, for example 69.1％。

In one embodiment, the modified Y-type molecular sieve for heavy oil hydrocracking of the present invention has a relative crystal retention of 49% or more, preferably 49% to 54%, for example, 51.37% after aging at 800 ℃ under normal pressure in a 100% steam atmosphere for 17 hours, indicating a higher hydrothermal stability.

In one embodiment, in step (1), the NaY molecular sieve is stirred while in contact with the NaY mother liquor and warmed to facilitate solid-liquid separation.

In one embodiment, in the step (1), the NaY molecular sieve is contacted with the NaY mother liquor under stirring, the temperature is raised to 40-90 ℃, the dilute acid solution is slowly added, and the stirring is continued for 20-90 minutes, and then the filtration is carried out.

In one embodiment, in the step (1), the NaY molecular sieve may be a commercially available NaY molecular sieve. In one embodiment, in step (1) of preparing the modified Y-type molecular sieve, the NaY molecular sieve may be a NaY fraction The molecular sieve is synthesized, filtered and washed with industrial water to obtain NaY molecular sieve filter cake. In one embodiment, in the step (1), the NaY molecular sieve has a unit cell constant of 2.465 to 2.472nm, a framework silica to alumina ratio (SiO ₂ /Al ₂ O ₃ Molar ratio) of 4.5 to 5.2, a relative crystallinity of 85% or more, for example, 85 to 95%, and a sodium oxide content of 13.0 to 13.8% by weight.

In one embodiment, in said step (1), said NaY mother liquor is derived from a NaY molecular sieve synthesis process and is a byproduct of a NaY molecular sieve synthesis process. In one embodiment, in the step (1), the NaY mother liquor is a NaY mother liquor discharged from a NaY synthesis slurry after the NaY molecular sieve synthesis, which is a mother liquor remaining after the filtration and separation of the solid NaY molecular sieve, which is not reused in the NaY molecular sieve synthesis process, and is sometimes referred to herein as an externally discharged NaY mother liquor. In one embodiment, in step (1), the NaY mother liquor comprises about 25 to 40g/L SiO ₂ 。

In one embodiment, in the step (1), the ratio of the NaY molecular sieve to the NaY mother liquor is 1 to 1.9mL NaY mother liquor/g NaY molecular sieve. If the proportion of the NaY mother liquor is too low, the recycled Si source is low, the effect of protecting the crystallinity of the molecular sieve can not be achieved in the subsequent hydrothermal ultrastable, and if the proportion of the NaY mother liquor is too high, amorphous Si in the molecular sieve is excessive, and the specific surface area of the molecular sieve can be reduced.

In one embodiment, in the step (1), the purpose of adding the dilute acid is to perform a neutralization reaction with an alkaline soluble substance in the NaY mother liquor, so that the pH value of the NaY mother liquor is changed, and further, free soluble Si in the NaY mother liquor uniformly forms solid Si in the NaY molecular sieve, so that a sufficient active Si source capable of timely migrating to a dealumination vacancy is provided for a subsequent hydrothermal ultrastable process of the molecular sieve, and the crystallinity of the molecular sieve can be furthest protected from being damaged in the hydrothermal ultrastable process.

In one embodiment, in the step (1), the diluted acid may be diluted hydrochloric acid or diluted sulfuric acid or diluted nitric acid. In one embodiment, in said step (1), the concentration of said dilute acid solution is atH in solution ⁺ The molar concentration of (C) is 0.001 to 0.1mol/L, preferably 0.005 to 0.05mol/L. In one embodiment, in step (1), the volume of the dilute acid solution may be adjusted so that the free soluble Si in the NaY mother liquor may precipitate completely or nearly completely into the NaY molecular sieve to form solid Si uniformly. For example, in one embodiment, the volume ratio of dilute acid solution to NaY mother liquor may be from 0.5 to 1.5:1. in a preferred embodiment, the dilute acid solution is an aqueous solution of a dilute acid.

In one embodiment, in the step (1), the NaY molecular sieve is contacted with the NaY mother liquor under stirring, the temperature is raised to 50-75 ℃, and the dilute acid aqueous solution is slowly added, and after stirring is continued for 30-60 minutes, the filtration is performed.

In one embodiment, in the step (2), the NaY molecular sieve obtained in the step (1) is subjected to an ion exchange reaction with a rare earth salt solution to obtain a Y-type molecular sieve with reduced sodium oxide content.

In one embodiment, in step (2), the NaY molecular sieve (on a dry basis): rare earth salts (in RE) ₂ O ₃ Meter): h ₂ The weight ratio of O is 1:0.01 to 0.18:5 to 15, preferably 1:0.03 to 0.15: 7-12.

In one embodiment, in step (2), the molecular sieve is molecular sieve NaY (on a dry basis): rare earth salts (in RE) ₂ O ₃ Meter): h ₂ O=1: 0.01 to 0.18:5 to 15, and stirring at 15 to 95 ℃, preferably 65 to 95 ℃ for 30 to 120 minutes, preferably 45 to 90 minutes, for example, to exchange rare earth ions with sodium ions. In one embodiment, the water may be selected from, for example, decationized water, deionized water, or mixtures thereof. In one embodiment, the step of forming the NaY molecular sieve, rare earth salt, and water into a mixture may be performed by slurrying the NaY molecular sieve and water, then at The slurry is added with rare earth salt and/or rare earth salt solution.

In one embodiment, in the step (2), the rare earth salt may be rare earth chloride and/or rare earth nitrate. The rare earth may be selected from one or more of La, ce, pr, nd and misch metals, for example. In one embodiment, the misch metal contains one or more of La, ce, pr, and Nd, or at least one of the rare earths other than La, ce, pr, and Nd.

In one embodiment, in said step (2), the purpose of said washing is to wash out exchanged sodium ions. In one embodiment, in the step (2), deionized water or decationized water washing may be used.

In one embodiment, the reduced sodium oxide content Y-type molecular sieve obtained in step (2) has a rare earth content of RE on a dry weight basis ₂ O ₃ The content of sodium oxide is not more than 8 wt%, preferably 4.5-7.5 wt% or 4.5-6.5 wt%, and the unit cell constant is 2.465-2.472 nm.

In one embodiment, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at a temperature of 350 to 550 ℃ under a 30 to 95% by volume water vapor atmosphere for 4.5 to 8 hours. In a preferred embodiment, the firing temperature is 380 to 540 ℃. In a preferred embodiment, the firing atmosphere is a 40 to 90% by volume steam atmosphere. In a preferred embodiment, the calcination time is from 5 to 7 hours. In a preferred embodiment, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at 380 to 540 ℃ for 5 to 7 hours in a 40 to 90% by volume water vapor atmosphere.

In one embodiment, when preparing the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at a temperature of 350 to 520 ℃ under a 30 to 85% by volume water vapor atmosphere for 4.5 to 7 hours. In one embodiment, the firing temperature of step (3) is 380 to 480 ℃. In one embodiment, the firing atmosphere in step (3) is a 40 to 80% by volume steam atmosphere. In one embodiment, the firing time described in step (3) is from 5 to 6 hours. In one embodiment, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at 380 to 480 ℃ for 5 to 6 hours in a 40 to 80% by volume water vapor atmosphere.

In one embodiment, when preparing the modified Y-type molecular sieve containing phosphorus for heavy oil hydrocracking, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at a temperature of 450 to 550 ℃ under a 70 to 95% by volume water vapor atmosphere for 5 to 8 hours. In a preferred embodiment, the firing temperature is 480 to 540 ℃. In a preferred embodiment, the firing atmosphere is an 80 to 95% by volume steam atmosphere. In a preferred embodiment, the calcination time is from 5.5 to 7 hours. In a preferred embodiment, in the step (3), the mild hydrothermal ultrastable modification treatment is performed by calcining the Y-type molecular sieve obtained in the step (2) at a temperature of 535 ℃ under a 90 vol% steam atmosphere for 6.5 hours.

In one embodiment, the water vapor atmosphere contains 30 to 95% by volume, preferably 40 to 90% by volume, of water vapor and further contains other gases, such as one or more of air, helium, or nitrogen. In one embodiment, the water vapor atmosphere contains 70% water vapor by volume and 30% air by volume. In one embodiment, the water vapor atmosphere contains 75% water vapor by volume and 25% air by volume. In one embodiment, the water vapor atmosphere contains 80% water vapor by volume and 20% air by volume. In one embodiment, the water vapor atmosphere contains 90% water vapor by volume and 10% air by volume.

In one embodiment, in said step (3), the unit cell constant of the obtained Y-type molecular sieve with reduced unit cell constant is 2.448nm to 2.460nm.

In one embodiment, in the preparation of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, in said step (3), the unit cell constant of the obtained Y-type molecular sieve having a reduced unit cell constant is from 2.450nm to 2.459nm, for example, from 2.455nm, 2.456nm or 2.457nm.

In one embodiment, in the preparation of the modified Y-type molecular sieve containing phosphorus for heavy oil hydrocracking, in said step (3), the Y-type molecular sieve having a reduced unit cell constant is obtained having a unit cell constant of 2.448nm to 2.453nm, for example, 2.450nm.

In one embodiment, in the step (4), the Y-type molecular sieve having the unit cell constant reduced in the step (3) is subjected to a phosphorus modification treatment with a phosphorus compound to introduce phosphorus into the molecular sieve, thereby improving the coke selectivity of the catalyst and improving the heavy oil cracking ability.

In one embodiment, the phosphorus modification treatment described in step (4) generally comprises contacting the Y-type molecular sieve having a reduced unit cell constant obtained in step (3) with an exchange liquid comprising a phosphorus compound and water, typically at 15 to 100 c, preferably 30 to 95 c, for 10 to 100 minutes, followed by filtration and washing. Wherein the weight ratio of water in the exchange liquid to the Y-type molecular sieve (based on dry basis) is 2-5: 1, preferably 3 to 4:1, phosphorus (in P ₂ O ₅ Calculated on a dry basis) and the weight ratio of the Y-type molecular sieve (calculated on a dry basis) is 0.0005 to 0.07:1, preferably 0.001 to 0.05:1. in one embodiment, the washing is performed with water, for example with 5 to 15 times the weight of the molecular sieve water, such as decationized or deionized water.

In one embodiment, in the step (4), the phosphorus compound may be selected from one or more of phosphoric acid, ammonium phosphate, monoammonium phosphate, diammonium phosphate.

In one embodiment, in step (4), the phosphorus-modified Y-type molecular sieve is also dried so that the water content in the Y-type molecular sieve is preferably not more than 1% by weight. The drying may be carried out by existing methods, for example by air-flow drying, oven-drying, flash drying.

In one embodiment, in said step (5), siCl ₄ : the weight ratio of the Y-type molecular sieve with the reduced unit cell constant containing phosphorus (based on dry basis) is 0.1-0.85: 1, preferably 0.2 to 0.8:1, the temperature of the reaction is 200-620 ℃, preferably 250-600 ℃, and the reaction time is 10 minutes to 5 hours, preferably 30 minutes to 4 hours.

In one embodiment, in the preparation of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, siCl is used in the step (5) ₄ : the weight ratio of the Y-type molecular sieve with the reduced unit cell constant containing phosphorus (based on dry basis) is 0.1-0.7: 1, preferably 0.15 to 0.7:1, the temperature of the reaction is 200-600 ℃, preferably 250-550 ℃, and the reaction time is 10 minutes to 5 hours, preferably 30 minutes to 4 hours.

In one embodiment, in preparing a modified Y-type molecular sieve for heavy oil hydrocracking, in said step (5), the weight ratio of silicon tetrachloride to said Y-type molecular sieve having a reduced unit cell constant of phosphorus on a dry basis is from 0.6 to 0.85:1, for example 0.75:1, the temperature of the reaction is 450-620 ℃, preferably 500-600 ℃, e.g. 580 ℃, and the reaction time is 10 minutes to 5 hours, preferably 30 minutes to 4 hours, e.g. 3 hours.

In one embodiment, the step (5) may comprise washing. In one embodiment, step (5) may not include washing. In one embodiment, the step (5) may or may not be dried after washing. In one embodiment, in step (5), when washing is performed, a conventional washing method may be employed, for example, washing with water, for example, washing with decationized water or deionized water, in order to remove Na remaining in the molecular sieve ⁺ 、Cl ^- Al and Al ³⁺ And the like. In one embodiment, the washing conditions may be: the weight ratio of the washing water to the Y-type molecular sieve (on a dry basis) can be 5-20: 1, preferably 6 to 15:1, the pH value of the washing mixed solution is preferably 2.5-5.0, and the washing temperature is 30-60 ℃. In one embodimentNa in the washing liquid after washing ⁺ 、Cl ^- Al and Al ³⁺ The respective content of ions is not more than 0.05% by weight. In a preferred embodiment, no free Na is detected in the washing solution after washing ⁺ 、Cl ^- Al and Al ³⁺ And (3) plasma.

In one embodiment, preparing a modified Y-type molecular sieve containing phosphorus for use in the catalytic cracking of heavy oils comprises the steps of:

(1) Contacting NaY molecular sieve with NaY mother liquor while stirring, heating to 50-75 ℃, slowly adding dilute acid aqueous solution, then continuing stirring for 30-60 minutes, and filtering;

(2) Contacting the NaY molecular sieve obtained in the step (1) with a rare earth salt solution, carrying out ion exchange reaction for 30-120 minutes at the temperature of 15-95 ℃, filtering and washing to obtain a Y-type molecular sieve with reduced sodium oxide content;

(3) Roasting the Y-type molecular sieve with reduced sodium oxide content obtained in the step (2) for 4.5-7 hours at the temperature of 350-520 ℃ in the atmosphere containing 30-85% by volume of water vapor, and performing mild hydrothermal ultra-stable modification treatment to obtain the Y-type molecular sieve with reduced unit cell constant;

(4) Contacting the obtained Y-type molecular sieve with reduced unit cell constant with exchange liquid of phosphorus-containing compound and water, carrying out exchange reaction for 10-100 minutes at 15-100 ℃ to carry out phosphorus modification treatment, and then filtering, washing and drying to obtain the Y-type molecular sieve with reduced unit cell constant containing phosphorus;

(5) Combining the Y-type molecular sieve with SiCl, wherein the unit cell constant of the phosphorus-containing molecular sieve is reduced, and the unit cell constant of the phosphorus-containing molecular sieve is reduced, which is obtained in the step (4) ₄ The gas is contacted and reacted under the condition of 200-600 ℃, wherein SiCl ₄ : weight ratio of Y-type molecular sieve with reduced unit cell constant of phosphorus on dry basis = 0.1-0.7: 1, the reaction time is 10 minutes to 5 hours, and then the modified Y-type molecular sieve containing phosphorus is obtained through washing and filtering.

In the method for preparing the modified Y-type molecular sieve containing phosphorus, firstly, in the step (1), a silicon source is introduced by recovering NaY mother liquor, so that free soluble Si in the NaY mother liquor uniformly forms solid Si in the NaY molecular sieve, a sufficient active Si source capable of timely migrating to a dealumination vacancy is provided for the subsequent hydrothermal ultrastable process of the molecular sieve, and the crystallinity of the molecular sieve can be furthest protected from being damaged in the hydrothermal ultrastable process. Secondly, in the step (3), the hydrothermal ultrastable process is alleviated by controlling the hydrothermal ultrastable condition, including controlling the temperature to be 350-550 ℃, controlling the steam atmosphere to contain 30-95% by volume of steam, and controlling the roasting time to be 4.5-8 hours, and the molecular sieve maintains higher crystallinity in the hydrothermal ultrastable process. And (3) in the step (5), silicon tetrachloride gas is contacted with the molecular sieve at a higher temperature to perform isomorphous substitution dealumination silicon supplementing reaction with Al in a molecular sieve framework structure on the basis that the molecular sieve still keeps higher crystallinity after hydrothermal superstable, so that the framework silicon-aluminum ratio of the molecular sieve can be further improved under the condition that the molecular sieve keeps higher crystallinity. The step (1) and the steps (3) and (5) are organically combined to realize relay dealumination and silicon supplementation of the molecular sieve under the condition of keeping higher crystallinity, so that the relative crystallinity of the phosphorus-containing modified Y-type molecular sieve obtained by the invention is not lower than 60%, the relative crystallinity retention is not lower than 45%, and the framework silicon-aluminum ratio is as high as 8.8-36, preferably 9.5-34; the structural collapse temperature is up to 1070 ℃ or higher, which shows that the phosphorus-containing modified Y-type molecular sieve prepared by the invention keeps higher crystallinity under the condition of higher silicon-aluminum ratio in the framework, and has high thermal and hydrothermal stability.

In addition, in the method for preparing the modified Y-type molecular sieve containing phosphorus, through the phosphorus modification in the step (4), the surface of the molecular sieve can be modified, so that the coke selectivity of the modified molecular sieve is improved to a great extent.

The method for preparing the modified Y-type molecular sieve containing phosphorus can basically recycle Si remained in the discharged NaY mother liquor generated in the NaY molecular sieve synthesis process. In the invention, si in the NaY mother liquor is used for post-modification of the NaY molecular sieve, so that the problem of P-type impurity crystals generated in the process of synthesizing the NaY molecular sieve by using the NaY mother liquor for excessive recycling in the prior art can be avoided. The method can also prepare the phosphorus-containing modified Y-type molecular sieve with high framework silicon-aluminum ratio, high crystallinity, high thermal stability and high hydrothermal stability.

In a further aspect, the invention provides a modified Y-type molecular sieve containing phosphorus prepared by the method of the invention, which contains 1 to 10 wt%, preferably 1 to 9 wt%, based on the dry weight of the molecular sieve, of RE ₂ O ₃ The content of the rare earth oxide is calculated; 0.05 to 6% by weight, preferably 0.5 to 4% by weight, of P ₂ O ₅ Phosphorus by meter; sodium oxide content of 0.05 to 0.5 wt%; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36, preferably 9.5-34; the unit cell constant is 2.428 nm-2.450 nm, preferably 2.429-2.448 nm; specific surface area of not less than 645m ² Preferably 650-680 m ² /g; the lattice collapse temperature is not lower than 1070 ℃, preferably 1070-1095 ℃; the relative crystallinity is not less than 60%, preferably 60 to 80%, more preferably 65 to 75%.

In one embodiment, the phosphorus-containing modified Y-type molecular sieve prepared according to the method of the present invention has a relative crystal retention of 45% or more, for example, 46 to 54% after aging at 800℃under normal pressure under 100% steam atmosphere for 17 hours.

In one embodiment, the modified Y-type molecular sieve containing phosphorus prepared by the method can be used for heavy oil catalytic cracking, has higher heavy oil conversion activity, higher liquefied gas yield, gasoline yield, light oil yield and total liquid yield than the existing Y-type molecular sieve, and has better coke selectivity.

In one embodiment, the invention provides a modified Y-type molecular sieve containing phosphorus and used for heavy oil catalytic cracking, which is prepared by the method and contains 4 to 10 weight percent of RE based on the total weight of dry basis ₂ O ₃ 0.05 to 6 weight percent of rare earth oxide calculated as P ₂ O ₅ 0.1 to 0.5 weight percent of sodium oxide calculated by phosphorus and the Si/Al ratio of the framework is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-19, the unit cell constant is 2.435 nm-2.450 nm, the total pore volume is 0.35 mL/g-0.40 mL/g, and the crystal latticeThe collapse temperature is not lower than 1070 ℃, the relative crystallinity is 60-80%, and the specific surface area is 645-670 m ² /g。

In one embodiment, the modified Y-type molecular sieve containing phosphorus and used for heavy oil catalytic cracking prepared by the method of the invention contains 4.5 to 9 weight percent of RE ₂ O ₃ The rare earth oxide is calculated.

In one embodiment, the modified Y-type molecular sieve containing phosphorus and used for heavy oil catalytic cracking prepared by the method of the invention contains 0.5 to 4 weight percent of P ₂ O ₅ Phosphorus in a meter.

In one embodiment, the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, which is prepared by the method disclosed by the invention, contains 0.1-0.5 wt% of sodium oxide.

In one embodiment, the framework silica-alumina ratio of the phosphorus-containing modified Y-type molecular sieve for heavy oil catalytic cracking prepared by the method of the invention is SiO ₂ /Al ₂ O ₃ The molar ratio is 9.5 to 18, preferably 10 to 17.7.

In one embodiment, the modified Y-type molecular sieve containing phosphorus, which is prepared by the method and is used for catalytic cracking of heavy oil, has a unit cell constant of 2.436 nm-2.448 nm.

In one embodiment, the total pore volume of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, which is prepared by the method disclosed by the invention, is 0.36-0.39 mL/g.

In one embodiment, the modified Y-type molecular sieve containing phosphorus, which is prepared by the method and is used for catalytic cracking of heavy oil, has a lattice collapse temperature of 1070-1080 ℃.

In one embodiment, the relative crystallinity of the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking, which is prepared by the method disclosed by the invention, is 65-75%.

In one embodiment, the phosphorus-containing modified Y-type molecular sieve for heavy oil catalytic cracking prepared by the method of the inventionThe specific surface area is 650-665 m ² /g。

In one embodiment, the modified Y-type molecular sieve containing phosphorus for heavy oil catalytic cracking prepared according to the method of the present invention has a relative crystal retention of 45% or more, preferably 46 to 52% after aging at 800 ℃ under normal pressure in a 100% steam atmosphere for 17 hours.

In another embodiment, the modified Y-type molecular sieve containing phosphorus prepared by the method can be used for hydrocracking heavy oil, and has higher hydrogenation activity (toluene conversion rate) and hydrocracking activity (n-decane conversion rate) than the existing Y-type molecular sieve.

In one embodiment, the invention provides a modified Y-type molecular sieve containing phosphorus and used for hydrocracking heavy oil, which is prepared by the method, and the content of rare earth oxide is RE based on the total weight of dry basis ₂ O ₃ From 1 to 4 wt%, for example 1.3 wt%; with P ₂ O ₅ The phosphorus content is 0.05 to 6 wt%, for example 0.84 wt%; sodium oxide content is 0.25 wt.%, for example 0.09 wt.%; silicon-aluminum ratio of skeleton is SiO ₂ /Al ₂ O ₃ The molar ratio is 20 to 36, for example 31.68; the total pore volume is 0.39mL/g to 0.43mL/g, for example 0.408mL/g; the unit cell constant is 2.428nm to 2.434nm, for example 2.429nm; the lattice collapse temperature is not lower than 1090 ℃, for example, 1092 ℃; specific surface area of not less than 670m ² /g, e.g. 671m ² /g; the relative crystallinity is not less than 65%, for example, 69.1%.

The phosphorus-containing modified Y-type molecular sieve prepared by the method provided by the invention has the advantages of high framework silicon-aluminum ratio, high crystallinity, high thermal stability and high hydrothermal stability. The modified Y-type molecular sieve containing phosphorus can be used as an active component for preparing a catalyst for heavy oil catalytic cracking, and the catalyst has higher liquefied gas yield, gasoline yield, light oil yield and total liquid yield when being used for heavy oil conversion, and has good coke selectivity. The modified Y-type molecular sieve containing phosphorus can also be used as an acidic component for preparing a catalyst for heavy oil hydrocracking, and the catalyst has higher hydrogenation activity (toluene conversion rate) and hydrocracking activity (n-decane conversion rate) when being used for hydrocracking.

The following examples further illustrate the invention, but are not intended to limit it.

Raw materials

In examples and comparative examples, naY molecular sieves (also referred to as NaY zeolite) were used as supplied by Qilu division, china petrochemical catalyst Co., ltd, and had a sodium oxide content of 13.5% by weight and a framework silica alumina ratio (SiO ₂ /Al ₂ O ₃ Molar ratio) =4.6, unit cell constant of 2.470nm, relative crystallinity of 90%; the NaY mother liquor is provided by the middle petrochemical catalyst Qilu division company and is discharged from the mother liquor which is remained after the solid NaY molecular sieve is filtered and separated in the NaY molecular sieve synthesis slurry and cannot be recycled in the NaY molecular sieve synthesis process, wherein SiO ₂ The mass concentration is 30g/L, wherein the Si recycling rate in the NaY mother liquor part recycled to the NaY molecular sieve synthesis process is known to be 75%; the rare earth chloride and the rare earth nitrate are chemical pure reagents produced by Beijing chemical plant; pseudo-boehmite is an industrial product produced by Shandong aluminum factory, and has the solid content of 61 weight percent; the kaolin is special for cracking catalyst produced by Suzhou China kaolin company, and has 76 weight percent of solid content; the alumina sol was supplied by ziluta corporation, a chinese petrochemical catalyst, with an alumina content of 21 wt.%. Raw oil Wu Mi San-2007 is purchased from Zhongpetrochemical Wuhan division. The chemical reagents used in the examples and comparative examples are not particularly noted and are of chemically pure specifications.

Analysis method

In each of the examples and comparative examples, the elemental content of the molecular sieve was determined by X-ray fluorescence spectrometry; the unit cell constant and the relative crystallinity of the Y-type molecular sieve are measured by an X-ray powder diffraction (XRD) method by adopting RIPP145-90 and RIPP146-90 standard methods (see the editions of petrochemical analysis method (RIPP test method) Yang Cuiding, etc., scientific Press, 1990); the framework silicon-aluminum ratio of the Y-type molecular sieve is calculated by the following formula: siO (SiO) ₂ /Al ₂ O ₃ ＝(2.5858-a ₀ )×2/(a ₀ -2.4191)]Wherein，a ₀ Is the unit cell constant, in nm; the collapse temperature of the crystal structure was determined by Differential Thermal Analysis (DTA).

In each of the examples and comparative examples, the total pore volume and specific surface area of the molecular sieve were measured according to adsorption isotherms in accordance with the RIPP 151-90 standard method (RIPP test method) under the heading Yang Cuiding et al, scientific Press, 1990.

In each example, the method for calculating the reuse rate of Si in NaY mother liquor:

the total amount of NaY mother liquor produced per 1 gram of NaY synthesized in the NaY synthesis was about 7.64mL.

Total Si recycle rate in NaY mother liquor = Si recycle rate in NaY mother liquor recycled to NaY synthesis process + Si recycle rate in externally discharged NaY mother liquor used in the present invention

The reuse rate of Si in the NaY mother liquor recycled to the NaY synthesis process in the prior art is known to be about 62% to 75%, whereas the reuse rate of Si in the NaY mother liquor recycled to the NaY synthesis process used in the examples of the present invention is about 75%.

Recovery of Si in the externally discharged NaY mother liquor used in the present invention = recovery amount of externally discharged NaY mother liquor used in the present invention (mL)/NaY dry basis weight (g)/7.64 (mL/g)

Total Si recovery in NaY mother liquor = 75% + the recovery of the externally discharged NaY mother liquor used in the present invention (mL)/NaY dry basis weight (g)/7.64 (mL/g)

In each of examples and comparative examples, the conversion, light oil yield, total liquid yield and coke selectivity in the evaluation of the catalytic cracking reaction performance of heavy oil of the catalyst were calculated by:

conversion = gasoline yield + liquefied gas yield + dry gas yield + coke yield

Light oil yield = petrol yield + diesel yield

Total liquid yield = liquefied gas yield + gasoline yield + diesel yield

Coke selectivity = coke yield/conversion.

Example 1

2000g (dry basis) of NaY molecular sieve filter cake (solid content 46%, sodium oxide content 13.5% by weight) was used as a medium petrochemical catalyst, qilu division Co., ltd.Is added with stirring to a mixture containing 2050mL of NaY mother liquor (from Middleja catalyst Qilu Co., ltd., wherein SiO ₂ 30 g/L) and heating to 50 ℃ under stirring, then slowly adding H ⁺ 1864mL of dilute hydrochloric acid having a molar concentration of 0.011mol/L was added, followed by stirring for 30 minutes and filtration. Then, the mixture was put into a primary exchange tank containing 20L of water and stirred uniformly at 25℃and 720mL of RE (NO) was added ₃ ) ₃ Solution (rare earth solution concentration with RE) ₂ O ₃ Measured as 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95 deg.C for 1 hr, filtering, washing, and drying the filter cake at 120 deg.C to obtain sodium oxide with unit cell constant of 2.471nm and sodium oxide content of 5.6 wt% and RE ₂ O ₃ The Y-type molecular sieve with 10.6 weight percent of rare earth content is calculated, then baked for 5.5 hours under the atmosphere of 405 ℃ containing 70 volume percent of water vapor and 30 volume percent of air to obtain the Y-type molecular sieve with the unit cell constant of 2.456nm, after cooling, the molecular sieve is added into 6L of aqueous solution dissolved with 32 g of phosphoric acid, the temperature is raised to 90 ℃ for 30 minutes of phosphorus modification treatment, after that, the molecular sieve is filtered and washed, and the filter cake is dried to have the water content of less than 1 weight percent, and then SiCl is added ₄ : y-type molecular sieve (dry basis) =0.55: 1 weight ratio, siCl vaporized by heating is introduced ₄ The modified Y-type molecular sieve provided by the invention is obtained by reacting the gas for 2.5 hours at 480 ℃, washing the gas with 20 liters of decationized water, and filtering the gas, wherein the physicochemical properties of the modified Y-type molecular sieve are shown in table 1, the molecular sieve before and after aging of the SZ1 is analyzed by XRD after the SZ1 is aged for 17 hours at 800 ℃ by 1atm and 100% water vapor, and the relative crystallization retention degree after aging is calculated, and the result is shown in table 2, wherein:

Example 2

2000g (dry basis)Heavy) NaY molecular sieve cake (solid content 46%, sodium oxide content 13.5% by weight, product of Mitsu catalyst Qilu Co., ltd.) was added to a slurry containing 2415mL of NaY mother liquor (Mitsu catalyst Qilu Co., ltd., wherein SiO ₂ 30 g/L) and heating to 70 ℃ under stirring, then slowly adding H ⁺ 2012mL of dilute nitric acid having a molar concentration of 0.012mol/L, and then, stirring was continued for 60 minutes, followed by filtration. Then, the mixture was put into a primary exchange tank containing 20L of water, stirred uniformly at 25℃and 890mL of RECl was added ₃ Solution (in RE) ₂ O ₃ The solution concentration was: 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95 deg.C for 1 hr, filtering, washing, and drying the filter cake at 120 deg.C to obtain powder with unit cell constant of 2.471nm, sodium oxide content of 5.0 wt% and RE ₂ O ₃ The Y-type molecular sieve with the rare earth content of 12.5 weight percent is calculated, then baked for 6 hours under the atmosphere of 470 ℃ containing 80 volume percent of water vapor and 20 volume percent of air to obtain the Y-type molecular sieve with the unit cell constant of 2.457nm, after cooling, the molecular sieve is added into 6L of aqueous solution dissolved with 122 g of ammonium phosphate, the temperature is raised to 60 ℃ for 50 minutes of phosphorus modification treatment, after that, the molecular sieve is filtered and washed, and the filter cake is dried to the water content of less than 1 weight percent, and then SiCl is added ₄ : y-type molecular sieve = 0.65:1 weight ratio, siCl vaporized by heating is introduced ₄ The gas was reacted at 475℃for 2 hours, after which it was washed with 20 liters of decationized water and filtered to give a modified Y-type molecular sieve, designated SZ2. The physical and chemical properties are shown in Table 1, and after SZ2 was aged at 800℃for 17 hours with 100% steam in the bare state, the relative crystallinity of the molecular sieve before and after the aging of SZ2 was analyzed by XRD and the relative crystallinity retention after the aging was calculated, and the results are shown in Table 2.

Example 3

2000g (dry basis) of NaY molecular sieve filter cake (solid content 46%, sodium oxide content 13.5% by weight) was used in the well petrochemical catalyst Qilu company industryProduct) was added with stirring to a solution containing 2735mL of NaY mother liquor (available from Mitrolitification catalyst Qilu Co., ltd., wherein SiO ₂ 30 g/L) and heating to 50 ℃ under stirring, then slowly adding H ⁺ 1954mL of dilute sulfuric acid having a molar concentration of 0.014mol/L was stirred for 30 minutes and then filtered. Then, the mixture was put into a primary exchange tank containing 20L of water and stirred uniformly at 25℃and 795mL of RECl was added thereto ₃ Solution (in RE) ₂ O ₃ The concentration of the calculated rare earth solution is 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95deg.C, stirring for 1 hr, filtering, washing, and drying the filter cake at 120deg.C to obtain powder with unit cell constant of 2.471nm, sodium oxide content of 5.7 wt% and RE ₂ O ₃ The Y-type molecular sieve with the rare earth content of 11.7 weight percent is calculated, then baked for 5.5 hours under the atmosphere of 475 ℃ containing 75 volume percent of water vapor and 25 volume percent of air to obtain the Y-type molecular sieve with the unit cell constant of 2.455nm, after cooling, the molecular sieve is added into 6L of aqueous solution dissolved with 83 g of diammonium hydrogen phosphate, the temperature is raised to 40 ℃ for 80 minutes of phosphorus modification treatment, after filtering and washing the molecular sieve, and drying the filter cake to make the water content of the filter cake lower than 1 weight percent, then the filter cake is processed according to SiCl ₄ : y-type molecular sieve (dry basis) =0.45: 1 weight ratio, siCl vaporized by heating is introduced ₄ The gas was reacted at 505℃for 2 hours, after which it was washed with 20 liters of decationized water and then filtered to give a modified Y-type molecular sieve, designated SZ3. The physical and chemical properties are shown in Table 1, and after SZ3 was aged in a bare state with 100% steam at 800℃for 17 hours, the relative crystallinity of the molecular sieve before and after SZ3 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Example 4

2000g (dry basis) of NaY molecular sieve filter cake (solid content: 46%, sodium oxide content: 13.5% by weight, product of Mitsui catalyst Qilu Co., ltd.) was added to a NaY mother liquor (NaY mother liquor was obtained from Mitsui catalyst Qilu Co., ltd.) containing 2995mL while stirringFor, among others, siO ₂ 30 g/L) and heating to 50 ℃ under stirring, then slowly adding H ⁺ 2995mL of diluted hydrochloric acid having a molar concentration of 0.01mol/L was added, followed by stirring for 30 minutes and filtration. Then, the mixture was put into a primary exchange tank containing 20L of water and stirred uniformly at 25℃and 850mL of RE (NO) was added ₃ ) ₃ Solution (rare earth solution concentration with RE) ₂ O ₃ Measured as 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95 deg.C for 1 hr, filtering, washing, and drying the filter cake at 120 deg.C to obtain sodium oxide with unit cell constant of 2.471nm and sodium oxide content of 5.1 wt% and RE ₂ O ₃ The Y-type molecular sieve with the rare earth content of 12.1 weight percent is calculated, then baked for 6.5 hours under the atmosphere of 535 ℃ containing 90 volume percent of water vapor and 10 volume percent of air to obtain the Y-type molecular sieve with the unit cell constant of 2.450nm, after cooling, the molecular sieve is added into 6L of aqueous solution dissolved with 35 g of phosphoric acid, the temperature is raised to 90 ℃ for 30 minutes of phosphorus modification treatment, then the molecular sieve is filtered and washed, and the filter cake is dried to the water content of less than 1 weight percent, and then SiCl is added ₄ : y-type molecular sieve (dry basis) =0.75: 1 weight ratio, siCl vaporized by heating is introduced ₄ The gas was reacted at 580℃for 3 hours, then washed with 20 liters of deionized water, and then filtered to obtain the modified Y-type molecular sieve of the present invention, designated SZ4, the physicochemical properties of which are shown in Table 1, and after SZ4 was aged at 800℃for 17 hours with 1atm and 100% steam in a bare state, the relative crystallinity of the molecular sieve before and after aging of SZ4 was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Comparative example 1

2000 g of NaY molecular sieve (based on dry matter) are added into 20L of decationizing aqueous solution and stirred to be mixed uniformly, 1000 g (NH) are added ₄ ) ₂ SO ₄ Stirring, heating to 90-95 deg.C, holding for 1 hr, filtering, washing, drying filter cake at 120 deg.C, calcining at 650 deg.C and 100% water vapor for 5 hrWhen it is subjected to hydrothermal modification treatment, then, the mixture is added into 20L of decationized aqueous solution and stirred to be uniformly mixed, 1000 g (NH) of the mixture is added ₄ ) ₂ SO ₄ Stirring, heating to 90-95 ℃ and keeping for 1 hour, filtering, washing, drying the filter cake at 120 ℃, roasting at 650 ℃ and 100% steam for 5 hours, and performing a second hydrothermal modification treatment to obtain the twice ion exchange twice hydrothermal ultrastable rare earth-free hydrothermal ultrastable Y-type molecular sieve, which is marked as DZ1. The physical and chemical properties are shown in Table 1, and after DZ1 was aged at 800℃for 17 hours with 100% steam in the bare state, the relative crystallinity of the molecular sieve before and after DZ1 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Comparative example 2

2000 g of NaY molecular sieve (based on dry matter) are added into 20L of decationizing aqueous solution and stirred to be mixed uniformly, 1000 g (NH) are added ₄ ) ₂ SO ₄ Stirring, heating to 90-95 deg.C, holding for 1 hr, filtering, washing, drying filter cake at 120 deg.C, hydrothermal modifying at 650 deg.C with 100% water vapor for 5 hr, adding into 20L of decationizing aqueous solution, stirring, mixing, adding 200ml RE (NO) ₃ ) ₃ Solution (in RE) ₂ O ₃ The concentration of the rare earth solution is as follows: 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) 900 g (NH) ₄ ) ₂ SO ₄ Stirring, heating to 90-95 ℃ for 1 hour, filtering, washing, drying the filter cake at 120 ℃, and then performing a second hydrothermal modification treatment (roasting for 5 hours at the temperature of 650 ℃ and 100% steam) to obtain the twice ion-exchanged twice hydrothermal ultrastable rare earth-containing hydrothermal ultrastable Y-type molecular sieve, which is marked as DZ2. The physical and chemical properties are shown in Table 1, and after DZ2 was aged at 800℃for 17 hours with 100% steam in the bare state, the relative crystallinity of the molecular sieve before and after DZ2 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Comparative example 3

2000 g of NaY molecular sieve (dry basis) was added to 22L of decationized aqueous solution and stirred to mix well, 570mL of RECl was added ₃ Solution (in RE) ₂ O ₃ The concentration of the calculated rare earth solution is 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95deg.C, stirring for 1 hr, filtering, washing, and drying the filter cake at 120deg.C to obtain powder with unit cell constant of 2.471nm, sodium oxide content of 7.5 wt% and RE ₂ O ₃ The Y-type molecular sieve with the rare earth content of 8.5 weight percent is calculated, then the molecular sieve is added into 6L of aqueous solution with 95 g of diammonium hydrogen phosphate, the temperature is raised to 40 ℃ for 80 minutes of phosphorus modification treatment, then the molecular sieve is filtered and washed, the filter cake is dried to make the water content of the filter cake lower than 1 weight percent, and then the filter cake is processed according to SiCl ₄ : y-type molecular sieve (on a dry basis) =0.4: 1 weight ratio, siCl vaporized by heating is introduced ₄ The gas was reacted at 580℃for 1.5 hours, after which it was washed with 20 liters of decationized water and then filtered to give a modified Y-type molecular sieve, designated DZ3. The physical and chemical properties are shown in Table 1, and after DZ3 was aged at 800℃for 17 hours with 100% steam in the bare state, the relative crystallinity of the molecular sieve before and after SZ3 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Comparative example 4

2000 g of NaY molecular sieve (on a dry basis) was added to 20L of the decationized aqueous solution and stirred to mix well, 600mL of RE (NO) was added ₃ ) ₃ Solution (rare earth solution concentration with RE) ₂ O ₃ Measured as 319g/L, RE ₂ O ₃ Contains 64.5% of Ce ₂ O ₃ And 35.5% La ₂ O ₃ ) Stirring, heating to 90-95 deg.C for 1 hr, filtering, washing, and drying the filter cake at 120 deg.C to obtain sodium oxide with unit cell constant of 2.471nm and sodium oxide content of 7.0 wt% and RE ₂ O ₃ Y-type molecular sieve with rare earth content of 8.8 wt% is calculated, and then contains 50 volume% of water vapor and 50 volume% of air at 390 DEG CCalcining for 6 hours under the atmosphere of gas to obtain a Y-type molecular sieve with a unit cell constant of 2.455nm, cooling, adding the molecular sieve into 6L of aqueous solution dissolved with 35 g of phosphoric acid, heating to 90 ℃ for 30 minutes of phosphorus modification treatment, filtering and washing the molecular sieve, drying the filter cake until the water content is lower than 1 weight percent, and then preparing the molecular sieve according to SiCl ₄ : y-type molecular sieve (on a dry basis) =0.5: 1 weight ratio, siCl vaporized by heating is introduced ₄ The gas was reacted at 400℃for 2 hours, then washed with 20 liters of deionized water, and then filtered to obtain the modified Y-type molecular sieve of the present invention, which was designated as DZ4, and its physicochemical properties are shown in Table 1, and after DZ4 was aged at 800℃for 17 hours with 1atm and 100% steam in a bare state, the relative crystallinity of the molecular sieve before and after DZ4 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Comparative example 5

Comparative example 5 is a process for preparing an acidic component modified Y molecular sieve in a hydrocracking catalyst of the prior art.

(1) 100g (dry basis) of NaY molecular sieve (manufactured by Mitsui catalyst, unit cell constant: 2.466nm, relative crystallinity: 90.2%, na) ₂ O content: 13.5, siO ₂ /Al ₂ O ₃ Molar ratio: 5.11, it is known that the reuse rate of Si in the NaY mother liquor recycled to the NaY molecular sieve synthesis process in the preparation process thereof is 75 percent, and the mixture is dispersed in 1300mL of water, and 100mL of an aqueous solution containing 45g of ammonium nitrate (purchased from Beijing Yili chemical reagent plant) is dropwise added at a constant speed at 35 ℃ with stirring (the dropwise addition time is controlled to be 40 min). After the water solution is added dropwise, stirring is stopped, the mixed solution is filtered, the solid phase is washed 3 times by deionized water, and the solid phase is dried for 3.5 hours under normal pressure in an air atmosphere at 110 ℃ to obtain the exchanged molecular sieve.

(2) Placing 85g (dry basis) of the exchanged molecular sieve prepared in the step (1) in a tube furnace, continuously introducing water vapor (the introducing speed of the water vapor is 0.30 mL/(min. G of molecular sieve)) into the tube furnace, maintaining the temperature in the tube furnace at 600 ℃, and performing hydrothermal treatment for 2.5 h. And naturally cooling to the ambient temperature, and taking out to obtain the molecular sieve after the first hydrothermal treatment.

(3) 80g (dry basis) of the first hydrothermally treated molecular sieve was dispersed in 1000mL of distilled water, and 150mL of an aqueous solution containing 60g of ammonium sulfate and 10g of sulfuric acid was added dropwise at a constant speed at 35℃with stirring (the addition time was controlled to be 45 min). After the completion of the dropwise addition, stirring was continued for 60 minutes. Then, the solid phase was filtered, washed with deionized water 2 times, and dried under normal pressure in an air atmosphere at 110 ℃ for 3 hours, thereby obtaining a dealuminated molecular sieve.

(4) Placing 60g (dry basis) of the molecular sieve obtained in the step (3) in a tube furnace, continuously introducing a mixed gas of steam and air (the introducing speed of the steam is 0.3 mL/(min. G of molecular sieve), the introducing amount of the air is 15L/(min. G of molecular sieve)) into the tube furnace, maintaining the temperature in the tube furnace at 620 ℃, and performing hydrothermal treatment for 3 hours. And naturally cooling to the ambient temperature after the hydrothermal treatment is finished to obtain the molecular sieve after the second hydrothermal treatment.

(5) 60g (dry basis) of the second hydrothermally treated molecular sieve prepared in the step (4) was dispersed in 650mL of distilled water, the mixture was heated to 60℃and 100mL of an aqueous solution containing 25g of ammonium chloride and 15g of fluosilicic acid was added dropwise at a constant speed with stirring (the addition time was controlled to be 25 min). After the completion of the dropwise addition, stirring was continued for 30 minutes. And after the temperature naturally drops to the ambient temperature, filtering the mixture, washing the solid phase with deionized water for 2 times, and drying the solid phase in an air atmosphere at 110 ℃ for 3 hours at normal pressure to obtain the dealuminated Y-type molecular sieve.

(6) 5g of nickel nitrate and 20g of ammonium heptamolybdate are dissolved in 100mL of water, 25 weight percent of concentrated ammonia water is added dropwise at the rate of 5mL/min, blue precipitation starts to appear, the solution is continuously added dropwise to dissolve the precipitation, and the pH value is continuously added dropwise to reach 11, so that 145mL of blue transparent solution is obtained.

(7) And (3) adding 100g of the dealuminated Y-type molecular sieve prepared in the step (5) into the blue transparent solution obtained in the step (6), continuously stirring for 2 hours, filtering, washing with clear water, drying at 115 ℃ for 1.5 hours, and roasting at 280 ℃ for 2 hours to obtain the modified molecular sieve DZ5.

The physicochemical properties of DZ5 are given in Table 1. The molecular sieves before and after DZ5 was aged at 800℃for 17 hours with 1atm and 100% water vapor in the bare state, and the relative crystallinity of the molecular sieves before and after DZ5 aging was analyzed by XRD and the relative crystallinity retention after aging was calculated, and the results are shown in Table 2.

Examples 5 to 7

Examples 5-7 illustrate the catalytic cracking reaction performance of the modified Y-type molecular sieves containing phosphorus prepared in examples 1-3 of the present invention.

First, modified Y-type molecular sieves SZ1, SZ2, SZ3 containing phosphorus of examples 1 to 3 were prepared into catalytic cracking catalysts (respectively designated as SC1, SC2, SC 3), and the specific steps were as follows:

714.5 g of an alumina sol having an alumina content of 21% by weight was added to 1565.5 g of decationized water, stirring was started, and 2763 g of kaolin having a solid content of 76% by weight was added to disperse for 60 minutes. 2049 g of pseudo-boehmite with the alumina content of 61 weight percent is taken to be added into 8146 g of decationized water, 210mL of hydrochloric acid with the mass concentration of 36 percent is added under the stirring state, the dispersed kaolin slurry is added after acidification for 60 minutes, then 1500 g (dry basis) of ground SZ1, SZ2 and SZ3 molecular sieves are respectively added, and after uniform stirring, spray drying and washing treatment are carried out, and drying is carried out, thus respectively obtaining microsphere catalysts SC1, SC2 and SC3. Wherein, based on dry basis, the obtained SC1, SC2 and SC3 catalysts respectively contain 30 weight percent of SZ1, SZ2 and SZ3 molecular sieves, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

The SC1, SC2 and SC3 catalysts were then aged for 17 hours at 800 ℃ with 100% steam and their catalytic cracking reactions were evaluated on a small fixed fluidized bed reactor (ACE), and the cracked gas and product oil were collected and analyzed by gas chromatography. The catalyst loading was 9g, the reaction temperature was 500℃and the weight hourly space velocity was 16h ^-1 The ratio (weight ratio) of the agent to the oil is 5, the raw oil of ACE experiment is Wu mixed three-2007, the property is shown in Table 3, and the evaluation result is shown in Table 4.

Comparative examples 6 to 9

Comparative examples 6 to 9 illustrate the catalytic cracking reaction performance of the modified Y-type molecular sieves prepared in comparative examples 1 to 4 of the present invention.

First, catalytic cracking catalysts DC1, DC2, DC3 and DC4 were prepared from modified Y-type molecular sieves DZ1, DZ2, DZ3 and DZ4 of comparative examples 1 to 4 according to the preparation methods described in examples 5 to 7. Wherein the obtained DC1, DC2, DC3 and DC4 catalysts respectively contain 30 weight percent of DZ1, DZ2, DZ3 and DZ4 molecular sieves, 42 weight percent of kaolin, 25 weight percent of pseudo-boehmite and 3 weight percent of alumina sol.

Then, after the DC1, DC2, DC3 and DC4 catalysts were aged for 17 hours at 800℃with 100% steam, the catalytic cracking reaction performance was evaluated on a small fixed fluidized bed reactor (ACE) by the methods described in examples 5 to 7, the raw oil for ACE experiments was Wu-Mi three-2007, the properties were described in Table 3, and the evaluation results are shown in Table 4.

Example 8

Example 8 illustrates a method for preparing a hydrocracking catalyst using the modified Y-type molecular sieve containing phosphorus provided in example 4 of the present invention as the acidic component of the hydrocracking catalyst and its hydrocracking reaction performance.

Preparation of hydrocracking catalyst: 31.5g of nickel nitrate was taken, and after adding water to 300mL of the solution to dissolve it completely, 60g of molecular sieve SZ-4 obtained in example 4 was taken and added to the solution, and the solution was heated to 96℃with stirring and stirred under reflux for 4 hours. After filtration, the mixture was rinsed twice with deionized water, dried at 120℃for 3 hours and calcined at 400℃for 2 hours. The prepared molecular sieve is crushed after tabletting, and the particles with 40 to 60 meshes are sieved for standby.

Micro-reverse evaluation: as reactants, a mixture of n-decane and toluene (weight ratio of the two: 9:1) was used. Loading 0.5g of 40-60 mesh catalyst particles into a reactor, and setting the hydrogen partial pressure at 300 ℃ and 4MPa and the vulcanized oil airspeed at 40h ^-1 Is vulcanized for 2 hours under the condition of 360 ℃, 4MPa hydrogen partial pressure and 40 hours of reaction oil airspeed ^-1 The hydrogenation activity (toluene conversion to first order reaction rate constant) and hydrocracking activity (n-decane conversion) of the catalyst were evaluated under the conditions of (a) and (b). The results are shown in Table 5.

Wherein, the materials after the reaction are analyzed by an online gas chromatography method, and the conditions include: using an agilent 6850 chromatograph, using an HP-1 chromatographic column, using a temperature programming method to measure, keeping at 40 ℃ for 2min, and keeping at 10 ℃/min to 160 ℃ for 2min. The method of chromatography-mass spectrometry is adopted in advance to carry out qualitative analysis on the cracked hydrocarbon with the carbon number of less than 10. Toluene (or n-decane) conversion= (molar amount of toluene (or n-decane) before reaction-molar amount of toluene (or n-decane) after reaction)/molar amount of toluene (or n-decane) before reaction, the higher the toluene conversion, the better the hydrogenation activity.

Comparative example 10

Comparative example 10 illustrates a method for preparing a hydrocracking catalyst using the modified Y-type molecular sieve provided in comparative example 5 of the present invention as an acidic component of the hydrocracking catalyst and hydrocracking reaction performance thereof.

The preparation method of the hydrocracking catalyst and the micro-reverse evaluation method of the hydrocracking reaction performance are the same as in example 8.

TABLE 1

As can be seen from Table 1, the modified Y-type molecular sieve containing phosphorus provided by the invention has high stability and high crystallinity, and simultaneously has low sodium oxide content. The molecular sieve has higher relative crystallinity and larger specific surface area when the silicon-aluminum ratio of the molecular sieve is higher, and the structural collapse temperature of the molecular sieve is high, which indicates that the molecular sieve has high thermal stability.

The method for preparing the modified Y-type molecular sieve containing phosphorus can carry out new recycling on Si in the part of NaY mother liquor which is produced in NaY synthesis and cannot be completely recycled in NaY synthesis, and Si in the recycled NaY mother liquor is directly used in post-modification production of the NaY molecular sieve, so that the utilization rate of Si sources is greatly improved, the total recycling rate of Si in the NaY mother liquor can be up to more than 88.4 percent and even up to 94.6 percent, and the preparation method can further reduce the production cost, reduce the waste water and waste residue emission of catalyst production enterprises and protect the environment.

TABLE 2

As shown in Table 2, after the modified Y-type molecular sieve containing phosphorus provided by the invention is aged for 17 hours under the severe conditions of 800 ℃ and 100% water vapor in the exposed state of a molecular sieve sample, the sample has higher relative crystallization retention degree, which indicates that the modified Y-type molecular sieve provided by the invention has high hydrothermal stability.

Table 3 ACE evaluation of raw oil properties

TABLE 4 Table 4

As can be seen from the results shown in tables 3 and 4, the catalytic cracking catalyst prepared by using the modified Y-type molecular sieve provided by the invention as an active component has higher heavy oil conversion activity, obviously higher gasoline yield, liquefied gas yield, light oil yield and total liquid yield, and obviously better coke selectivity.

Catalysts for hydrocracking heavy oil were also prepared and evaluated for catalytic performance using the modified Y-type molecular sieves containing phosphorus prepared according to the present invention as an acidic component as described in example 8 and comparative example 10, and the results are shown in table 5.

TABLE 5

Examples numbering	Molecular sieve numbering	Toluene conversion/%	N-decane conversion/%
				Example 8	SZ4	20.8	65.3
Comparative example 10	DZ5	19.1	60.7

As can be seen from Table 5, the heavy oil hydrocracking catalyst prepared by taking the phosphorus-containing modified Y-type molecular sieve prepared by the invention as an acidic component has higher toluene conversion rate and n-decane conversion rate, which shows that the heavy oil hydrocracking catalyst prepared by taking the modified Y-type molecular sieve prepared by the invention as an acidic component has higher hydrogenation activity (toluene conversion rate) and hydrocracking activity (n-decane conversion rate).

Unless defined otherwise, terms used herein are all meanings commonly understood by those skilled in the art.

The described embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of the present invention, since various substitutions, modifications and improvements can be made by those skilled in the art without departing from the true spirit and scope of the invention, and therefore, the present invention is not limited to the above embodiments but only by the claims.

Claims

1. A phosphorus-containing modified Y-type molecular sieve, wherein the phosphorus-containing modified Y-type molecular sieve contains 1 to 10 wt%, preferably 1 to 9 wt%, of RE, based on the total weight of the phosphorus-containing modified Y-type molecular sieve on a dry basis ₂ O ₃ 0.05 to 6 wt%, preferably 0.5 to 4 wt% of rare earth oxide, based on P ₂ O ₅ 0.05 to 0.5 weight percent of sodium oxide based on phosphorus,

the framework silicon-aluminum ratio of the phosphorus-containing modified Y-type molecular sieve is SiO ₂ /Al ₂ O ₃ The molar ratio is 8.8-36, preferably 9.5-34;

the unit cell constant of the modified Y-type molecular sieve containing phosphorus is 2.428 nm-2.450 nm, preferably 2.429 nm-2.448 nm;

the total pore volume of the modified Y-type molecular sieve containing phosphorus is 0.35-0.45 mL/g, preferably 0.36-0.43 mL/g;

The lattice collapse temperature of the phosphorus-containing modified Y-type molecular sieve is not lower than 1070 ℃, and is preferably 1070-1095 ℃;

the relative crystallinity of the modified Y-type molecular sieve containing phosphorus is not less than 60%, preferably 60-80%, more preferably 65-75%;

the specific surface area of the modified Y-type molecular sieve containing phosphorus is not less than 645m ² Preferably 650-680 m ² /g。

2. The modified Y-type molecular sieve containing phosphorus according to claim 1, wherein the relative crystal retention of the modified Y-type molecular sieve containing phosphorus is 45% or more, preferably 46 to 54% after aging at 800 ℃ under normal pressure under 100% steam atmosphere for 17 hours.

3. Use of the modified Y-type molecular sieve containing phosphorus according to claim 1 or 2 for heavy oil catalytic cracking.

4. Use of the modified Y-type molecular sieve containing phosphorus according to claim 1 or 2 for heavy oil hydrocracking.

5. A process for preparing a modified Y-type molecular sieve comprising phosphorus, comprising the steps of:

6. The method of claim 5, wherein in step (1), the dilute acid is dilute hydrochloric acid, dilute sulfuric acid, or dilute nitric acid, preferably the dilute acid solution is at a concentration of H in solution ⁺ The molar concentration of (2) is 0.001 to 0.1mol/L, preferably 0.005 to 0.05mol/L; preferably, the dilute acid solution is an aqueous solution of dilute acid.

7. A process according to claim 5 or 6, wherein in step (1) the NaY molecular sieve is contacted with the NaY mother liquor under agitation, the mixed slurry is warmed to 40 ℃ to 90 ℃, preferably 50 ℃ to 75 ℃, and the aqueous solution of dilute acid is added, and after continuing agitation for 20 to 90 minutes, preferably 30 to 60 minutes, filtration is carried out.

8. The process according to any one of claims 5 to 7, wherein in step (1), the NaY molecular sieve is a commercially available NaY molecular sieve or is a NaY molecular sieve filter cake which has been filtered and washed with industrial water after synthesis of the NaY molecular sieve; and/or the NaY mother liquor is the NaY mother liquor which is discharged after the NaY molecular sieve is synthesized, the solid NaY molecular sieve is filtered and separated from the NaY synthetic slurry, and the mother liquor which is remained after the NaY molecular sieve is not recycled in the NaY molecular sieve synthesis process.

9. The method according to claim 5 to 8,wherein in the step (2), the molecular sieve is prepared according to NaY: rare earth salt: h ₂ O=1: 0.01 to 0.18: 5-15 weight ratio of NaY molecular sieve, rare earth salt and water to form a mixture, stirring to perform ion exchange reaction, wherein the weight of NaY molecular sieve is calculated by dry basis, and the weight of rare earth salt is calculated by rare earth oxide; preferably, forming the NaY molecular sieve, rare earth salt and water into a mixture is accomplished by mixing the NaY molecular sieve with water, adding the rare earth salt and/or rare earth salt solution with stirring; preferably, the rare earth salt solution is an aqueous solution of rare earth salt; and preferably the rare earth salt is rare earth chloride and/or rare earth nitrate.

10. The method according to any one of claims 5 to 9, wherein in the step (2), the conditions of the ion exchange reaction are: the exchange temperature is 15-95 ℃, preferably 65-95 ℃, and the exchange time is 30-120 minutes, preferably 45-90 minutes.

11. The process according to any one of claims 5 to 10, wherein in step (3), the Y-type molecular sieve having a reduced sodium oxide content obtained in step (2) is calcined at a temperature of 350 to 550 ℃, preferably 380 to 540 ℃, 30 to 95% by volume, preferably 40 to 90% by volume, of a steam atmosphere for 4.5 to 8 hours, preferably 5 to 7 hours.

12. The process according to any one of claims 5 to 11, wherein in the step (4), the Y-type molecular sieve having a reduced unit cell constant obtained in the step (3) is contacted with an exchange liquid containing a phosphorus compound and water, and subjected to a phosphorus modification treatment by an exchange reaction at 15 to 100 ℃, preferably 30 to 95 ℃ for 10 to 100 minutes; wherein the weight ratio of water in the exchange liquid to the Y-type molecular sieve with reduced unit cell constant on a dry basis is 2-5: 1, preferably 3 to 4:1, a step of; with P ₂ O ₅ The weight ratio of phosphorus to the Y-type molecular sieve with reduced unit cell constant on a dry basis is 0.0005 to 0.07:1, preferably 0.001 to 0.05:1.

13. The method according to any one of claims 5 to 12, wherein in the step (4), the phosphorus compound is selected from one or more of phosphoric acid, ammonium phosphate, monoammonium phosphate, diammonium phosphate.

14. The process of any one of claims 5 to 13, wherein in step (4) the water content in the Y-type molecular sieve with reduced unit cell constant of phosphorus is no more than 1 wt%.

15. The method according to any one of claims 5 to 14, wherein in the step (5), siCl ₄ : weight ratio of the Y-type molecular sieve with reduced unit cell constant of phosphorus on a dry basis=0.1 to 0.85:1, preferably 0.2 to 0.8:1, a step of; the reaction temperature is 200-620 ℃, preferably 250-600 ℃; the reaction time is 10 minutes to 5 hours, preferably 30 minutes to 4 hours.

16. The modified Y-type molecular sieve containing phosphorus prepared by the process according to any one of claims 5 to 15, which contains 1 to 10 wt%, preferably 1 to 9 wt%, of RE, based on the total weight of its dry basis ₂ O ₃ 0.05 to 6 wt%, preferably 0.5 to 4 wt% of rare earth oxide, based on P ₂ O ₅ 0.05 to 0.5 weight percent of sodium oxide based on phosphorus,

17. The modified Y-type molecular sieve containing phosphorus according to claim 16, wherein the modified Y-type molecular sieve containing phosphorus has a relative crystal retention of 45% or more, preferably 46 to 54% after aging at 800 ℃ under normal pressure under 100% steam atmosphere for 17 hours.