Fluid catalytic cracking using a catalyst system containing a modified beta zeolite additive

Abstract

The method for cracking hydrocarbon oil includes contacting the hydrocarbon oil with a catalyst system in a fluid catalytic cracking unit to produce light olefins and gasoline fuel. The catalyst system includes an FCC basic catalyst and a catalyst additive. The FCC basic catalyst includes a Y-type zeolite. The catalyst additive includes a framework-substituted *BEA-type zeolite. The framework-substituted *BEA-type zeolite has a modified *BEA framework. The modified *BEA framework is a *BEA aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the *BEA aluminosilicate framework with a β-zeolite Al-substituted atom, and the β-zeolite Al-substituted atom is selected from titanium, zirconium, hafnium and a combination thereof. The FCC basic catalyst may include a framework-substituted ultrastable Y (USY) type zeolite as the Y-type zeolite. The framework-substituted USY type zeolite has a USY aluminosilicate framework modified by replacing a portion of the framework aluminum atoms with titanium, zirconium, hafnium or a combination thereof.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application serial number 16 / 985,588, filed on August 5, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a process for the fluid catalytic cracking of hydrocarbons, and more particularly to a process for the fluid catalytic cracking of hydrocarbon feedstocks using a catalyst system comprising a zeolite catalyst and a zeolite catalyst additive. Background Art

[0004] In the fluid catalytic cracking (FCC) process, petroleum-derived hydrocarbons are catalytically cracked using an acidic catalyst maintained in a fluidized state, wherein the acidic catalyst is regenerated on a continuous basis. The main product of these processes is usually gasoline. Other products are also produced in smaller quantities by the FCC process, such as liquefied petroleum gas and cracked gas oil. The coke deposited on the catalyst is burned off at high temperature in the presence of air before the regenerated catalyst is recycled back to the reaction zone.

[0005] Fluid catalytic cracking is the largest refining process for gasoline production, with a global capacity of more than 14.2 million barrels per day. The process converts heavy feedstocks such as vacuum distillates, atmospheric residues and deasphalted oils into light products rich in olefins and aromatics. FCC catalyst systems typically include fine particles such as zeolites, aluminum silicates, treated clays (kaolin), bauxite and solid acids of silica-alumina.

[0006] Additives may be included in FCC catalyst systems to significantly increase the octane number of the gasoline fraction or the yield of light olefins such as propylene. The demand for propylene continues to grow worldwide. Almost 60% of the total propylene is produced by steam cracking of various hydrocarbon streams such as naphtha, gas oil and liquefied petroleum gas (LPG). Greater than 30% of the propylene produced in the world is obtained from the FCC process. Therefore, there is a need for catalyst systems that generally increase propylene yields and catalyst additives that increase propylene yields in other known catalyst systems. Summary of the invention

[0007] Against the foregoing background, exemplary embodiments of the present disclosure relate to a method for cracking hydrocarbon oil. The method includes contacting the hydrocarbon oil with a catalyst system in a fluid catalytic cracking unit to produce light olefins and gasoline fuel. The catalyst system includes an FCC basic catalyst and a catalyst additive. The FCC basic catalyst includes a Y-type zeolite. The catalyst additive includes a framework-substituted *BEA-type zeolite. The framework-substituted *BEA-type zeolite has a modified *BEA framework. The modified *BEA framework can be a *BEA aluminosilicate framework that has been modified by replacing a portion of the framework aluminum atoms of the *BEA aluminosilicate framework with a β-zeolite Al-substituted atom, and the β-zeolite Al-substituted atom is independently selected from a titanium atom, a zirconium atom, a hafnium atom, and a combination thereof.

[0008] According to some embodiments, the Y-type zeolite of the FCC alkaline catalyst can be a framework-substituted ultrastable Y (USY)-type zeolite. In such an embodiment, the framework-substituted USY-type zeolite has a modified USY framework. The modified USY framework can be a USY aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the USY aluminosilicate framework with USY-zeolite Al-substituted atoms, and the USY-zeolite Al-substituted atoms are independently selected from titanium atoms, zirconium atoms, hafnium atoms and combinations thereof.

[0009]

[0011] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.

[0010] Additional features and advantages of the embodiments described herein will be set forth in the detailed description that follows, and in part will be apparent to those skilled in the art from the description or recognized by practicing the embodiments described herein, including the detailed description that follows, the claims, and the accompanying drawings.

[0011] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of a riser fluid catalytic cracking unit.

[0013] Figure 2 It is a schematic diagram of a downflow fluid catalytic cracking unit. DETAILED DESCRIPTION

[0014] Reference will now be made in detail to an embodiment of a method for cracking hydrocarbon oil. The method comprises contacting the hydrocarbon oil with a catalyst system in a fluid catalytic cracking unit to produce light olefins and gasoline fuel. The catalyst system comprises at least an FCC basic catalyst and a catalyst additive. The FCC basic catalyst comprises a Y-type zeolite.

[0015] The catalyst system of the embodiments, including the framework-substituted *BEA-type zeolite catalyst additive and its preparation will now be described in detail.The incorporation of the catalyst system in a process for fluid catalytic cracking of hydrocarbons will then be described.

[0016] FCC Alkaline Catalyst

[0017] In an embodiment of the method for cracking a hydrocarbon oil, the catalyst system contacted with the hydrocarbon oil comprises an FCC basic catalyst. The FCC basic catalyst may be any zeolite catalyst known to be suitable for use in a fluid catalytic cracking process. Suitable FCC basic cracking catalysts may have a bulk density of 0.5 g / mL to 1.0 g / mL, an average particle size of 50 μm to 90 μm, a particle size of 50 μm to 100 μm, a particle size of 100 μm to 100 μm, a particle size of 200 μm to 200 μm, a particle size of 300 μm to 500 μm, a particle size of 100 μm to 200 μm, a particle size of 200 μm to 300 μm, a particle size of 300 μm to 500 μm, a particle size of 200 μm to 200 μm, a particle size of 30 2 / g to 350m 2 / g surface area and 0.05mL / g to 0.5mL / g pore volume.

[0018] In an embodiment, the FCC basic catalyst is a Y-type zeolite or contains a Y-type zeolite. In some embodiments, the Y-type zeolite may be an ultrastable Y (USY) type zeolite. In some embodiments, the Y-type zeolite may be a modified USY-type zeolite, such as a skeleton-substituted USY-type zeolite. The FCC basic catalyst comprising a skeleton-substituted USY-type zeolite has a high cracking activity, can effectively produce light olefins and gasoline, and has a low yield of dry gas and coke. The skeleton-substituted USY-type zeolite will now be described in detail.

[0019] The framework-substituted ultrastable Y (USY)-type zeolite according to an embodiment has a modified USY framework. According to the standard definition of a USY aluminosilicate framework, the modified USY framework is an analog of a USY aluminosilicate framework. According to the standard definition, a USY aluminosilicate framework is a framework of an aluminosilicate zeolite having a lattice constant (UD) of 2.430 nm or more and 2.460 nm or less, a lattice constant (UD) of 600 nm or less, and a lattice constant (UD) of 600 nm or less. 2 / g-900m 2 / g specific surface area and a molar ratio of silicon to aluminum of 5-100 (calculated based on silicon dioxide (SiO2) and aluminum oxide (Al2O3)).

[0020] Regarding the framework-substituted USY-type zeolite according to an embodiment of the present disclosure, the modified USY framework is a USY aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the USY aluminosilicate framework with USY-zeolite Al-substituent atoms. In an embodiment, the USY-zeolite Al-substituent atoms are independently selected from titanium atoms, zirconium atoms, hafnium atoms and combinations thereof.

[0021] As used in the present disclosure, the term "Ti-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the substitution atom is titanium. Similarly, the term "Zr-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atom includes zirconium. The term "Hf-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atom includes hafnium. The term "(Ti,Zr)-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atom includes titanium and zirconium. The term "(Ti,Hf)-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atom includes titanium and hafnium. The term "(Zr,Hf)-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atom includes zirconium and hafnium. The term "(Ti,Zr,Hf)-USY" refers to a framework-substituted USY-type zeolite according to an embodiment, wherein the USY-zeolite Al-substituted atoms include titanium, zirconium and hafnium.

[0022] The USY-type zeolite of the framework substitution according to the embodiment can be Ti-USY, Zr-USY, Hf-USY, (Ti, Zr)-USY, (Ti, Hf)-USY, (Zr, Hf)-USY or (Ti, Zr, Hf)-USY as defined above. The USY-zeolite Al-substituted atoms replace the aluminum atoms that form the ultrastable Y-type zeolite framework, and are therefore used as components of the ultrastable Y-type zeolite framework. The substitution can be verified by analytical techniques, including but not limited to ultraviolet, visible and near-infrared spectrophotometry (UV-Vis-NIR), Fourier transform infrared spectroscopy (FT-IR) or nuclear magnetic resonance spectroscopy (NMR).

[0023] In some embodiments, based on the total mass of the framework-substituted USY-type zeolite, the framework-substituted USY-type zeolite includes 0.01 wt% to 5 wt%, or 0.1 wt% to 5 wt%, or 0.2 wt% to 4 wt%, or 0.3 wt% to 3 wt% of USY-zeolite Al-substituted atoms calculated on an oxide basis. In the calculation based on oxides, titanium atoms are calculated based on TiO2, zirconium atoms are calculated based on ZrO2, and hafnium atoms are calculated based on HfO2. Titanium, zirconium and hafnium in the framework-substituted USY-type zeolite can be quantitatively determined by known techniques, such as by X-ray fluorescence analysis, high-frequency plasma emission spectrometry or atomic absorption spectrometry.

[0024] In some embodiments, in addition to the substituted atoms substituted by the aluminum framework, the USY type zeolite substituted by the framework may also include zirconium atoms, titanium atoms, hafnium atoms or any combination thereof, which are connected to the framework of the USY type zeolite substituted by the framework, or are loaded on the framework of the USY type zeolite substituted by the framework, or are combined with the framework of the USY type zeolite substituted by the framework. In such an embodiment, zirconium, titanium or hafnium atoms can be connected as oxide particles (such as titanium dioxide particles, zirconium oxide particles or hafnium dioxide particles). The oxide particles may have a particle diameter of 50nm or less. For the purpose of quantitative analysis, as contemplated herein, based on oxide calculations and based on the total mass of the USY type zeolite substituted by the framework, the amount of the substituted atoms in the USY type zeolite substituted by the framework includes the total amount of titanium, zirconium and hafnium by mass, and titanium, zirconium and hafnium replace the framework aluminum atoms or are connected to the zeolite framework or are loaded on the outside of the zeolite framework or are combined with the zeolite framework. However, it is understood that in all embodiments, at least a portion of the framework aluminum atoms of the USY aluminosilicate framework are substituted by titanium atoms, zirconium atoms, hafnium atoms, or any combination thereof. In an exemplary embodiment, greater than 50%, or greater than 75%, or greater than 90%, or greater than 99% of the titanium, zirconium, and hafnium atoms present in the framework-substituted USY-type zeolite replace the framework aluminum atoms in the zeolite framework, and in particular as particles, are not only connected to the zeolite framework, or are loaded on the outside of the zeolite framework, or are combined with the zeolite framework.

[0025] It will be appreciated by those skilled in the art that when the framework-substituted USY-type zeolite contains a combination of USY-zeolite Al-substituted atoms, such as in (Ti,Zr)-USY, (Ti,Hf)-USY, (Zr,Hf)-USY or (Ti,Zr,Hf)-USY, the mass ratio (calculated on an oxide basis) of the various types of USY-zeolite Al-substituted atoms in each zeolite is not limited. Although the reaction described in the method according to the embodiment can be adjusted by adjusting the ratio of titanium, zirconium and hafnium, it will be appreciated that any ratio of titanium, zirconium and hafnium can effectively carry out the method for cracking hydrocarbon oil according to the present disclosure.

[0026] The framework-substituted USY zeolite in the catalyst system can be prepared by any zeolite preparation method that produces a framework-substituted USY zeolite having a USY aluminosilicate framework, wherein a portion of the framework aluminum atoms are substituted by titanium atoms, zirconium atoms, hafnium atoms, or any combination thereof. In an exemplary preparation technique, the framework-substituted USY zeolite in the catalyst system can be prepared by calcining a USY zeolite at 500° C. to 700° C., wherein the USY zeolite has a lattice constant of 2.430 nm to 2.460 nm and a specific surface area of ​​600 m 2 / g-900m 2 / g and a molar ratio of silica to alumina of 5-100. Then, a suspension containing a fired USY-type zeolite is formed. The suspension may have a liquid / solid mass ratio of 5-15. An inorganic acid or an organic acid is added to the suspension to reduce the pH of the suspension to less than 2.0. The pH of the suspension is pre-controlled to be less than 2.0 to prevent precipitation during mixing of one or more additional solutions. Specifically, one or more additional solutions containing compounds of zirconium, titanium, hafnium or a combination thereof are mixed into the suspension to cause framework substitution at the aluminum site. The suspension is then neutralized with an alkali (e.g., aqueous ammonia) to increase the pH to 7-7.5. The resulting framework-substituted USY-type zeolite may be filtered, washed with water, and dried at a drying temperature of, for example, 80°C-180°C.

[0027] In the preparation of the framework-substituted USY-type zeolite, the ultra-stable Y-type zeolite raw material can be calcined at 500°C-700°C or 550°C-650°C. There is no particular limitation on the calcination time, as long as the framework-substituted USY-type zeolite is obtained. An exemplary calcination time may be 30 minutes to 10 hours. Regarding the calcination atmosphere of the USY-type zeolite raw material, it is preferably carried out in air. The calcined USY-type zeolite raw material is suspended in water at a temperature of 20°C-30°C to form a suspension. Regarding the concentration of the suspension of USY-type zeolite, the liquid / solid mass ratio may be, for example, 5-15, or 8-12.

[0028] Non-limiting examples of inorganic acids used to reduce the pH of the suspension in the preparation of the framework-substituted USY zeolite may include sulfuric acid, nitric acid or hydrochloric acid. Examples of organic acids used to reduce the pH of the suspension in the preparation of the framework-substituted USY zeolite may include carboxylic acids. The amount of inorganic or organic acids is not limited as long as the pH of the suspension can be controlled to be less than 2.0. Non-limiting example amounts of acid include 0.5-4.0 times or 0.7-3.5 times the molar amount of acid of the molar amount of alumina in the framework-substituted USY zeolite.

[0029] Non-limiting examples of titanium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted USY-type zeolite include titanium sulfate, titanium acetate, titanium chloride, titanium nitrate, titanium lactate, and any titanium compound having sufficient solubility in the suspension to allow titanium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a titanium compound prepared by dissolving the titanium compound in water is suitable for use as the titanium compound.

[0030] Non-limiting examples of zirconium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted USY-type zeolite include zirconium sulfate, zirconium nitrate, zirconium chloride, and any zirconium compound having sufficient solubility in the suspension to allow zirconium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a zirconium compound prepared by dissolving the zirconium compound in water is suitable for use as the zirconium compound.

[0031] Non-limiting examples of hafnium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted USY-type zeolite include hafnium chloride, hafnium nitrate, hafnium fluoride, hafnium bromide, hafnium oxalate, and any hafnium compound having sufficient solubility in the suspension to allow hafnium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a hafnium compound prepared by dissolving the hafnium compound in water is suitable for use as the hafnium compound.

[0032] In the preparation of the framework-substituted USY zeolite, when an aqueous solution of a zirconium compound, a hafnium compound or a titanium compound is mixed with a suspension of an ultrastable Y-type zeolite, the aqueous solution can be gradually added to the suspension. After the aqueous solution is added to the suspension, the solution can be mixed by stirring for 3-5 hours at, for example, room temperature (25°C ± 10°C). In addition, after the mixing is completed, the above-mentioned mixed solution is neutralized by adding an alkali such as ammonia water so that its pH is controlled at 7.0-7.5, thereby obtaining a framework-substituted zeolite in a catalyst.

[0033] Catalyst Additives

[0034] In an embodiment of the method for cracking hydrocarbon oil, in addition to the FCC basic catalyst, the catalyst system contacting the hydrocarbon oil includes a catalyst additive. The catalyst additive includes a framework-substituted *BEA type zeolite. The framework-substituted *BEA type zeolite has a modified *BEA framework.

[0035] According to the standard definition of the *BEA aluminosilicate framework, the modified *BEA framework is an analog of the *BEA aluminosilicate framework. According to the standard definition, the *BEA aluminosilicate framework is the framework of a crystalline aluminosilicate zeolite, and the lattice constants a and b (UD) of the crystalline aluminosilicate zeolite are 1.260nm-1.270nm, the unit cell length c is 2.62nm-2.65nm, and the specific surface area is 400m 2 / g-800m 2 / g, and the molar ratio of silicon to aluminum is 10-200 based on silicon dioxide (SiO2) and aluminum oxide (Al2O3).

[0036] Regarding the framework-substituted *BEA-type zeolite according to an embodiment of the present disclosure, the modified *BEA aluminosilicate framework is a *BEA aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the *BEA aluminosilicate framework with β-zeolite Al-substitution atoms, and the β-zeolite Al-substitution atoms are independently selected from titanium atoms, zirconium atoms and hafnium atoms and combinations thereof.

[0037] As used in the present disclosure, the term "Ti-*BEA" refers to a framework-substituted *BEA-type zeolite according to an embodiment, wherein the substituting atom is titanium. Similarly, the term "Zr-*BEA" refers to a framework-substituted *BEA-type zeolite according to an embodiment, wherein the β-zeolite Al-substituting atom includes zirconium. The term "Hf-*BEA" refers to a framework-substituted *BEA-type zeolite according to an embodiment, wherein the β-zeolite Al-substituting atom includes hafnium. The term "(Ti,Zr)-*BEA" refers to a framework-substituted *BEA-type zeolite according to an embodiment, wherein the β-zeolite Al-substituting atom includes titanium and zirconium. The term "(Ti,Hf)-*BEA" refers to a framework-substituted *BEA-type zeolite according to an embodiment, wherein the β-zeolite Al-substituting atom includes titanium and hafnium. The term "(Zr,Hf)-*BEA" refers to a framework-substituted *BEA type zeolite according to an embodiment, wherein the β-zeolite Al-substituted atoms include zirconium and hafnium. The term "(Ti,Zr,Hf)-*BEA" refers to a framework-substituted *BEA type zeolite according to an embodiment, wherein the β-zeolite Al-substituted atoms include titanium, zirconium and hafnium.

[0038] The framework-substituted *BEA-type zeolite according to the embodiment can be Ti-*BEA, Zr-*BEA, Hf-*BEA, (Ti,Zr)-*BEA, (Ti,Hf)-*BEA, (Zr,Hf)-*BEA or (Ti,Zr,Hf)-*BEA as defined above. The Al-substituted atoms of the β-zeolite replace the aluminum atoms that form the *BEA-type zeolite framework and are therefore used as components of the *BEA-type zeolite framework. The substitution can be verified by analytical techniques, including but not limited to ultraviolet, visible and near-infrared spectrophotometry (UV-Vis-NIR), Fourier transform infrared spectroscopy (FT-IR) or nuclear magnetic resonance spectroscopy (NMR).

[0039] In some embodiments, the framework-substituted *BEA-type zeolite includes 0.01 wt% to 5 wt%, or 0.1 wt% to 5 wt%, or 0.2 wt% to 4 wt%, or 0.3 wt% to 3 wt% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite. In the calculation based on oxides, titanium atoms are calculated based on TiO2, zirconium atoms are calculated based on ZrO2, and hafnium atoms are calculated based on HfO2. The titanium, zirconium, and hafnium in the framework-substituted *BEA-type zeolite can be quantitatively determined by known techniques, such as by X-ray fluorescence analysis, high-frequency plasma emission spectrometry, or atomic absorption spectrometry.

[0040] In some embodiments, in addition to the Al-substituted atoms of the β-zeolite substituted by the aluminum framework, the framework-substituted *BEA-type zeolite may also include zirconium atoms, titanium atoms, hafnium atoms, or any combination thereof, which are connected to the framework of the framework-substituted *BEA-type zeolite, or are loaded on the outside of the framework of the framework-substituted *BEA-type zeolite, or are combined with the framework of the framework-substituted *BEA-type zeolite. In such an embodiment, zirconium, titanium or hafnium atoms can be connected as oxide particles (e.g., titanium dioxide particles, zirconium oxide particles or hafnium dioxide particles). The oxide particles may have a particle diameter of 50nm or less. For the purpose of quantitative analysis, as contemplated herein, the amount of substituted atoms in the framework-substituted *BEA-type zeolite is calculated based on oxides and based on the total mass of the framework-substituted *BEA-type zeolite, and the amount of substituted atoms in the framework-substituted *BEA-type zeolite includes the total amount of titanium, zirconium and hafnium by mass, and titanium, zirconium and hafnium replace the framework aluminum atoms or are connected to the zeolite framework or are loaded on the outside of the zeolite framework or are combined with the zeolite framework. However, it is understood that in all embodiments, at least a portion of the framework aluminum atoms of the *BEA aluminosilicate framework are substituted with titanium atoms, zirconium atoms, hafnium atoms, or any combination thereof. In exemplary embodiments, greater than 50%, or greater than 75%, or greater than 90%, or greater than 99% of the titanium, zirconium, and hafnium atoms present in the framework-substituted *BEA-type zeolite replace framework aluminum atoms in the zeolite framework, and particularly as particles, are not only attached to the zeolite framework, or are supported on the outside of the zeolite framework, or are combined with the zeolite framework.

[0041] It will be appreciated by those skilled in the art that when the framework-substituted *BEA-type zeolite contains a combination of β-zeolite Al-substituted atoms, such as in (Ti,Zr)-*BEA, (Ti,Hf)-*BEA, (Zr,Hf)-*BEA or (Ti,Zr,Hf)-*BEA, the mass ratio (calculated on an oxide basis) of the various types of β-zeolite Al-substituted atoms in each zeolite is not limited. Although the reactions described in the methods according to the embodiments can be adjusted by adjusting the ratios of titanium, zirconium and hafnium, it will be appreciated that any ratio of titanium, zirconium and hafnium can effectively carry out the method for cracking hydrocarbon oils according to the present disclosure.

[0042] The framework-substituted *BEA zeolite in the catalyst system can be prepared by any zeolite preparation method that produces a framework-substituted *BEA zeolite having a *BEA aluminosilicate framework, wherein a portion of the framework aluminum atoms are substituted by titanium atoms, zirconium atoms, hafnium atoms, or any combination thereof. In an exemplary preparation technique, the framework-substituted *BEA zeolite in the catalyst system is prepared by calcining a *BEA zeolite at 500° C. to 700° C., and the lattice constants a and b of the *BEA zeolite are 1.260 nm to 1.270 nm, the unit cell length c is 2.62 nm to 2.65 nm, and the specific surface area is 400 m 2 / g-800m 2 / g, and the molar ratio of silica to alumina is 10-200, or 10-100, or 30-70. Then, a suspension containing a fired *BEA-type zeolite is formed. Based on the liquid and solid present in the suspension, the suspension may have a liquid / solid mass ratio of 5 to 15. An inorganic acid or an organic acid is added to the suspension to reduce the pH of the suspension to less than 2.0. The pH of the suspension is pre-controlled to be less than 2.0 to prevent precipitation during mixing of one or more additional solutions. Specifically, one or more additional solutions containing compounds of zirconium, titanium, hafnium or a combination thereof are mixed into the suspension to cause framework substitution at the aluminum site. The suspension is then neutralized with an alkali (e.g., aqueous ammonia) to increase the pH to 7-7.5. The resulting framework-substituted *BEA-type zeolite can be filtered, washed with water, and dried at a drying temperature of, for example, 80°C-180°C.

[0043] In a specific and non-limiting exemplary preparation of a (Ti,Zr)-*BEA framework-substituted *BEA-type zeolite according to an embodiment, 51.4 g of a zeolite having a *BEA framework with a silica to alumina ratio of 28.5 was suspended in 450 g of deionized water and heated to 40° C. Then, 14.8 g of H2SO4 (25 wt%) was added together with 10.0 g of an aqueous solution of titanium sulfate (equivalent to 5 wt% TiO2), which was prepared by adding 1.52 g of titanium sulfate to 8.48 g of deionized water (equivalent to 33 wt% TiO2 in aqueous solution). Additional aqueous zirconium sulfate solution (2.8 g, constituting 18 wt% ZrO2) was added to the solution. The mixture was stirred at 60° C. for 4 hours, then filtered and washed with 1.5 liters of deionized water. The resulting zeolite was dried at 110° C. to obtain a framework-substituted zeolite (Ti,Zr)-*BEA.

[0044] In the preparation of the framework-substituted *BEA zeolite, when the aqueous solution of the zirconium compound, hafnium compound or titanium compound is mixed with the suspension of the *BEA zeolite, the aqueous solution can be gradually added to the suspension. After the aqueous solution is added to the suspension, the solution can be mixed by stirring for 3-5 hours at room temperature (25°C ± 10°C), for example. In addition, after the mixing is completed, the mixed solution is neutralized by adding an alkali such as ammonia water so that its pH is controlled at 7.0-7.5, thereby obtaining the framework-substituted zeolite in the catalyst.

[0045] In the preparation of the framework-substituted *BEA-type zeolite, the *BEA-type zeolite raw material can be calcined at 500°C-700°C or 550°C-650°C. The calcination time is not particularly limited as long as the framework-substituted *BEA-type zeolite is obtained. An exemplary calcination time may be 30 minutes to 10 hours. Regarding the calcination atmosphere of the *BEA-type zeolite raw material, it is preferably carried out in air. The calcined *BEA-type zeolite raw material is suspended in water at a temperature of 20°C-30°C to form a suspension. Regarding the concentration of the suspension of *BEA-type zeolite, the liquid / solid mass ratio can be, for example, 5-15, or 8-12.

[0046] Non-limiting examples of inorganic acids used to reduce the pH of the suspension in the preparation of the framework-substituted *BEA-type zeolite may include sulfuric acid, nitric acid or hydrochloric acid. Examples of organic acids used to reduce the pH of the suspension in the preparation of the framework-substituted *BEA-type zeolite may include carboxylic acids. The amount of inorganic or organic acid is not limited as long as the pH of the suspension can be controlled to be less than 2.0. Non-limiting example amounts of acid include 0.5-4.0 times or 0.7-3.5 times the molar amount of acid based on the molar amount of alumina in the framework-substituted *BEA-type zeolite.

[0047] Non-limiting examples of titanium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted *BEA-type zeolite include titanium sulfate, titanium acetate, titanium chloride, titanium nitrate, titanium lactate, and any titanium compound having sufficient solubility in the suspension to allow titanium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a titanium compound prepared by dissolving the titanium compound in water is suitable for use as the titanium compound.

[0048] Non-limiting examples of zirconium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted *BEA-type zeolite include zirconium sulfate, zirconium nitrate, zirconium chloride, and any zirconium compound having sufficient solubility in the suspension to allow zirconium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a zirconium compound prepared by dissolving the zirconium compound in water is suitable for use as the zirconium compound.

[0049] Non-limiting examples of hafnium compounds present in the additional solution mixed into the suspension during the preparation of the framework-substituted *BEA-type zeolite include hafnium chloride, hafnium nitrate, hafnium fluoride, hafnium bromide, hafnium oxalate, and any hafnium compound having sufficient solubility in the suspension to allow hafnium atoms to replace aluminum atoms in the zeolite framework. In an embodiment, an aqueous solution of a hafnium compound prepared by dissolving the hafnium compound in water is suitable for use as the hafnium compound.

[0050] According to an embodiment, the framework-substituted *BEA-type zeolite catalyst additive may have (a) a specific surface area of ​​400 m 2 / g-800m 2 / g; (b) the molar ratio of SiO2 to Al2O3 is 10-200; (c) the pore volume is 0.2cm 3 / g-0.6cm 3 / g; and (d) lattice constants a = 1.26nm-1.27nm, b = 1.26nm-1.27nm, and c = 2.62-2.65nm. The catalyst additive including the framework-substituted *BEA zeolite may have a diameter of 0.40mL / g to 0.75mL / g. In a non-limiting exemplary embodiment, the framework-substituted *BEA zeolite catalyst additive may include a (Ti, Zr)-*BEA zeolite having (a) a specific surface area of ​​400 m 2 / g-800m 2 / g; (b) the molar ratio of SiO2 to Al2O3 is about 60; (c) the pore volume is 0.38cm 3 / g-0.43cm 3 / g; and (d) lattice constants a=1.26nm-1.27nm, b=1.26nm-1.27nm, and c=2.62-2.65nm. The *BEA type zeolite catalyst additive may have mesopores with a diameter of 2nm to 100nm.

[0051] According to an embodiment of the method for cracking hydrocarbon oil, the catalyst system may include the FCC basic catalyst and the catalyst additive, and the weight ratio of the FCC basic catalyst to the catalyst additive is 2:1 to 1000:1, or 2:1 to 100:1, or 4:1 to 100:1, or 6:1 to 20:1, or about 9:1, based on the combined weight of the FCC basic catalyst and the catalyst additive.

[0052] In a non-limiting exemplary embodiment of the method for cracking hydrocarbon oil, the catalyst additive is a (Ti,Zr)-*BEA framework-substituted *BEA type zeolite containing 0.01% to 5% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA type zeolite; the β-zeolite Al-substituted atoms include titanium atoms and zirconium atoms; based on the total mass of the framework-substituted ultra-stable Y-type zeolite, calculated on an oxide basis, the FCC basic catalyst is a (Ti,Zr)-USY framework-substituted ultra-stable Y-type zeolite containing 0.01% to 5% of USY-zeolite Al-substituted atoms; the USY-zeolite Al-substituted atoms include titanium atoms and zirconium atoms.

[0053] Optional components of the catalyst system

[0054] In an embodiment of the method for cracking hydrocarbon oil, the catalyst system contacting the hydrocarbon oil may optionally further include one or more of a catalyst substrate support, a binder, a filler and an active metal component in addition to the FCC base catalyst and the catalyst additive.

[0055] The catalyst system according to the method of the embodiment may also include a carrier for an FCC basic catalyst and the skeleton-substituted *BEA-type zeolite catalyst additive. In some embodiments, the carrier may include an inorganic oxide, excluding one or both of the FCC basic catalyst and the skeleton-substituted *BEA-type zeolite catalyst additive. The inorganic oxide of the carrier may also include a substance used as a granulating agent or a binder. Any substance contained in any known zeolite catalyst matrix carrier may be used, including as a granulating agent. Examples of such inorganic oxides include, but are not limited to, alumina, silica, titania, silica-alumina, alumina-titania, alumina-zirconia, alumina-boria, phosphorus-alumina, silica-alumina-boria, phosphorus-alumina-boria, phosphorus-alumina-silica, silica-alumina-titania and silica-alumina-zirconia. In an exemplary embodiment, the catalyst system includes an inorganic oxide selected from alumina and silica-alumina as a carrier. The silica-alumina carrier may be amorphous.

[0056] In embodiments where the catalyst system includes a catalyst matrix support, the weight ratio of zeolite to catalyst matrix support can vary depending on the desired catalyst activity level. In an exemplary embodiment, the mass of the catalyst matrix support in the catalyst system is determined relative to the mass of the zeolite in the catalyst system, without considering other components of the catalyst system. In an exemplary embodiment, based on the total mass of all zeolites in the catalyst system, the catalyst system can include 10 wt% to 80 wt%, 20 wt% to 70 wt%, or 25 wt% to about 65 wt% of zeolite. Similarly, the catalyst system can include a catalyst matrix support, the composition of which accounts for 20 wt% to 90 wt%, or 30 wt% to 80 wt%, or 35 wt% to 75 wt% of the catalyst system based on the total mass of the catalyst system.

[0057] In other exemplary embodiments, the catalyst system can include a binder, such as a silica-based binder or an alumina-based binder. Silica-based binders and alumina-based binders can be used as inorganic binders. The silica-based binder can be any one or two or more of silica sol, water glass (sodium silicate), and silicic acid liquid. For example, silica sol including SiO2 in the range of 10 wt% to 15 wt% can be prepared by simultaneously and continuously adding water glass including SiO2 in the range of 12 wt% to 23 wt% and sulfuric acid in the range of 20 wt% to 30 wt%. The aluminum compound binder can be (a) basic aluminum chloride, (b) aluminum dihydrogen phosphate, or (c) alumina sol. A solution obtained by dissolving any kind or two or more of microcrystalline alumina (such as gibbsite, bayerite, and boehmite) in an acid solution can alternatively be used as the aluminum compound binder. Here, basic aluminum chloride is represented as [Al2(OH) n Cl 6-n m , where n is an integer, m is a natural number, and where 0 < n < 6 and 1 < m < 10, or in some embodiments, where 4.8 < n < 5.3 and 3 < m < 7.

[0058] ​The catalyst system of the method according to the embodiment may also include an active metal component of a single metal or a combination of metals selected from IUPAC Groups 7 to 11 of the periodic table. Examples of active metals include iron, cobalt, nickel, rhodium, palladium, silver, iridium, platinum, gold, chromium, molybdenum and tungsten. Non-limiting examples of combinations of metal components include a combination of molybdenum and tungsten; a combination of cobalt and nickel; and a combination of any one or more of molybdenum, tungsten, cobalt or nickel with a platinum group metal such as platinum, rhodium or palladium. In an exemplary embodiment, the catalyst system may include at least one active phase metal selected from nickel, molybdenum, tungsten, platinum, palladium and a combination thereof. Without being bound by theory, it is believed that the framework substitution of aluminum by titanium, zirconium or hafnium in the framework-substituted USY-type zeolite according to the embodiment can promote a greater amount of active metal distribution on the surface of the zeolite catalyst.

[0059] When an active metal component is included in the catalyst system, the catalyst system may contain greater than 0 to about 40 wt% of the metal component, based on the total mass of the catalyst system, the oxide component is calculated on an oxide basis or the metal is calculated on a metal basis. In an exemplary embodiment, based on the total mass of the catalyst system, the catalyst system may include 3 wt% to 30 wt% of a metal component such as iron, cobalt, nickel, rhodium, palladium, silver, iridium, platinum, gold, chromium, molybdenum or tungsten, calculated on an oxide basis. In other exemplary embodiments, based on the total mass of the catalyst system, the catalyst system may include 0.01 wt% to 2 wt% of a metal component selected from platinum, rhodium or palladium.

[0060] In addition to the FCC base catalyst and the framework-substituted *BEA-type zeolite catalyst additive, the catalyst system of the method according to the embodiment may also include an additional FCC catalyst as an additive. Examples of such additional FCC catalysts may include a shape-selective zeolite having a pore size smaller than that of a Y-type zeolite, thereby selectively allowing hydrocarbons having only a limited shape to enter the zeolite through its pores. Examples of suitable shape-selective zeolite components include, for example, ZSM-5 zeolite, ω zeolite, SAPO-5 zeolite, SAPO-11 zeolite, SAPO-34 zeolite, and pentasil-type aluminosilicates. When present in the catalyst system, the content of the additional shape-selective zeolite in the catalyst system may be from about 0.01 wt% to 30 wt%, or from about 0.01 wt% to 20 wt%, based on the total mass of the catalyst system.

[0061] In a non-limiting exemplary embodiment, in a method for cracking hydrocarbon oil, the catalyst system may include the FCC basic catalyst, the catalyst additive, a catalyst matrix carrier, a binder and a filler. In such exemplary embodiments, the catalyst matrix carrier may include alumina or silica-alumina; the binder may be a sol of a porous inorganic oxide selected from alumina, silica, boria, chromia, magnesia, zirconium oxide, titania, silica-alumina and combinations thereof; and the filler may be a clay selected from kaolin, montmorillonite, halloysite, bentonite and combinations thereof. In a non-limiting embodiment, based on the total weight of the catalyst system, the catalyst system may include: 1 wt% to 50 wt% of the FCC basic catalyst; 1 wt% to 50 wt% of the catalyst additive; 0.1 wt% to 15 wt% of the binder; and 0.1 wt% to 15 wt% of the clay. In further non-limiting embodiments, the catalyst system may include: 1 wt% to 50 wt% of an FCC base catalyst; 1 wt% to 50 wt% of a catalyst additive; 0.1 wt% to 15 wt% of a binder; and 0.1 wt% to 15 wt% of clay, based on the total weight of the catalyst system, and the weight ratio of the FCC base catalyst to the catalyst additive in the catalyst system may be 6:1 to 20:1, based on the combined weight of the FCC base catalyst and the catalyst additive.

[0062] Fluid Catalytic Cracking Process

[0063] In the process for cracking hydrocarbon oil, the hydrocarbon oil is contacted with the catalyst system as described above in a fluid catalytic cracking unit to produce light olefins and gasoline fuel. A cracking process including the catalyst system as an integral component will now be described in detail.

[0064] In certain embodiments of the method, a hydrocarbon oil mixture having a boiling point range greater than 350° C. is provided, and the reactor is operated at a reaction temperature range of 450° C. to 700° C., a pressure of 1 bar to 10 bar, a residence or contact time of about 0.1 seconds to about 60 seconds, and a catalyst to oil weight ratio of about 2: 1 to about 30: 1. The fluid catalytic cracking can be operated under conditions effective to maximize the production of gasoline and light olefins and / or under conditions effective to maximize the production of light olefins.

[0065] As used herein, "heavy hydrocarbons" refers to petroleum fractions having a nominal boiling point greater than 350°C, including common refinery streams such as vacuum gas oil (VGO), unconverted bottoms or cycle oil from a hydrocracker, deasphalted oil (DAO) obtained from a solvent deasphalting process, demetallized oil, light or heavy coker gas oil obtained from a coking process, cycle oil obtained from a separate fluid catalytic cracking process or recycled from an FCC process using the catalyst of the present invention, gas oil obtained from a visbreaking process, or a combination comprising hydrogenated derivatives of at least one of the foregoing sources or oils.

[0066] According to some embodiments, the fluid catalytic cracking unit may include a riser reactor or a downcomer reactor. As used in the present disclosure, the term "downcomer" refers to a reactor, such as a fluidized bed reactor, in which reactants flow in a generally downward direction, such as entering the top of the reactor and leaving the bottom of the reactor. Similarly, the term "riser" refers to a reactor, such as a fluidized bed reactor, in which reactants flow in a generally upward direction, such as entering the bottom of the reactor and leaving the top of the reactor.

[0067] The catalyst system suitable for the specific charge and the desired product can be transported to one or more fluid catalytic cracking reactors. In certain embodiments, in order to promote the formation of olefins (including but not limited to propylene), and to minimize olefin consumption reactions (such as hydrogen transfer reactions), an FCC catalyst mixture is used in the FCC unit, including an FCC basic catalyst and an FCC catalyst additive.

[0068] Based on the fluid catalytic cracking of the catalyst for fluid catalytic cracking according to the present invention can be carried out under the common conditions of the fluid catalytic cracking of hydrocarbon oil.For example, the conditions described below can be used appropriately.Catalyst system as mentioned above can be packed in the reactor vessel, and is applicable to the catalytic cracking of hydrocarbon oil according to known FCC method, to produce gasoline and / or light olefins comprising ethene, propylene and butylene.

[0069] In fluid catalytic cracking, the hydrocarbon oil may be derived from one or more of crude oil, synthetic crude oil, asphalt, oil sands, shale oil and coal liquefaction oil. These feeds may include petroleum fractions with a normal boiling point greater than 350° C., including naphtha, diesel, vacuum gas oil (VGO), deasphalted oil (DAO) obtained from a solvent deasphalting process, demetallized oil, light or heavy coker gas oil obtained from a coking process, cycle oil obtained from a separate fluid catalytic cracking process or recycled from an FCC process using the catalyst of the present invention, gas oil obtained from a visbreaking process, or a combination comprising at least one of the foregoing.

[0070] For example, a catalytic cracking unit is equipped with the above-mentioned FCC catalyst, and a hydrocarbon oil having a boiling point greater than 350°C, and in certain embodiments having a boiling point of about 350°C to about 850°C, can be cracked using fluid catalytic cracking at a reaction temperature of about 450°C to about 700°C, a pressure of 1 bar to 10 bar, a residence or contact time of about 0.1 seconds to about 60 seconds, and a catalyst to oil weight ratio of about 2:1 to about 30:1.

[0071] In certain embodiments, a fluid catalytic cracking unit configured with a riser reactor is provided that operates under conditions that promote the formation of light olefins, particularly propylene, and minimize light olefin-consuming reactions including hydrogen transfer reactions. Figure 1 1 is a simplified schematic diagram of a riser fluidized catalytic cracking unit. The fluidized catalytic cracking unit 150 includes a riser reactor. The fluidized catalytic cracking unit 150 includes a reactor / separator 160 having a riser section 161, a reaction zone 163 and a separation zone 165. The fluidized catalytic cracking unit 150 also includes a regeneration vessel 167 for regenerating spent catalyst. The charge 136 is introduced into the reaction zone, accompanied by steam or other suitable gas for atomization of the feed (not shown) in certain embodiments. The charge 136 is mixed and intimately contacted with an effective amount of heated fresh or regenerated solid cracking catalyst particles, which are transported from the regeneration vessel 167 through a conduit 169. The feed mixture and the cracking catalyst are contacted under conditions to form a suspension, which is introduced into the riser 161. In a continuous process, a mixture of cracking catalyst and hydrocarbon feedstock passes upward through the riser 161 into the reaction zone 163. In the riser 161 and reaction zone 163, the thermal cracking catalyst particles catalytically crack relatively large hydrocarbon molecules by breaking carbon-carbon bonds.

[0072] During the reaction, as is conventional in fluid catalytic cracking operations, the cracking catalyst becomes coked, so access to active catalytic sites is limited or nonexistent. The reaction products are separated from the coked catalyst using any suitable configuration known in fluid catalytic cracking units, which is generally referred to as a separation zone 165 in the fluid catalytic cracking unit 150, such as the top of the reactor 160 located above the reaction zone 163. The separation zone may include any suitable device known to those of ordinary skill in the art, such as a cyclone separator. The reaction products are removed through conduit 171. Catalyst particles containing coke deposits from the fluid cracking of the hydrocarbon feedstock enter the regeneration zone 167 through conduit 173. According to the method herein, since the light solvent feedstock is combined with the heavy feedstock as feed 136, the ratio of solvent to oil in the initial solvent deasphalting / demetallization process is selected so as to provide sufficient coking of the catalyst, thereby providing heat balance during regeneration.

[0073] In regeneration zone 167, the coked catalyst is contacted with a stream of oxygen-containing gas (e.g., pure oxygen or air) entering regeneration zone 167 via conduit 175. Regeneration zone 167 is operated in a configuration and under conditions known in typical fluid catalytic cracking operations. For example, regeneration zone 167 can be operated as a fluidized bed to produce a regeneration off-gas including combustion products, which is discharged via conduit 177. The hot regenerated catalyst is transferred from regeneration zone 167 via conduit 169 to the bottom of riser 161 for mixing with the hydrocarbon feedstock, as described above.

[0074] Typically, suitable operating conditions for the reactor of a riser fluid catalytic cracking unit using the catalysts herein include: a reaction temperature of about 480°C to about 650°C, in certain embodiments a reaction temperature of about 500°C to about 620°C, and in other embodiments a reaction temperature of about 500°C to about 600°C; a pressure of about 1 kg / cm 2 About 20kg / cm 2 The reaction pressure is about 1 kg / cm 2 About 10kg / cm 2 The reaction pressure is about 1 kg / cm 2 About 3kg / cm 2 reaction pressure; about 0.5 seconds to about 10 seconds of contact time (in the reactor), in certain embodiments about 1 second to about 5 seconds of contact time (in the reactor), in other embodiments about 1 second to about 2 seconds of contact time (in the reactor); about 1:1 to about 15:1 catalyst to feed ratio, in certain embodiments about 1:1 to about 10:1 catalyst to feed ratio, in other embodiments about 8:1 to about 20:1 catalyst to feed ratio.

[0075] In certain embodiments, a fluid catalytic cracking unit configured with a downflow reactor is provided that operates under conditions that promote the formation of light olefins, particularly propylene, and minimize light olefin-consuming reactions including hydrogen transfer reactions. Figure 2It is a simplified schematic diagram of a downflow fluidized catalytic cracking unit. The fluidized catalytic cracking unit 250 includes a reactor / separator 260 having a reaction zone 262 and a separation zone 264. The fluidized catalytic cracking unit 250 also includes a regeneration zone 266 for regenerating spent catalyst. In particular, the charge 236 is introduced into the reaction zone, and in certain embodiments, steam or other suitable gases are used for atomization of the feed (not shown). An effective amount of heated fresh or hot regenerated solid cracking catalyst particles from the regeneration zone 266 is transported to the top of the reaction zone 262, and is also transported to the output well or hopper (not shown) at the top of the reaction zone 262, for example, by a downwardly directed conduit or pipe 268 (commonly referred to as a delivery line or vertical pipe). The hot catalyst flow is usually allowed to stabilize so as to be uniformly guided into the mixing zone or feed injection portion of the reaction zone 262. The charge 236 is injected into the mixing zone through a feed injection nozzle, which is generally located near the point where the regenerated catalyst is introduced into the reaction zone 262. These multiple injection nozzles cause the catalyst and oil to be fully and evenly mixed. Once the charge contacts the hot catalyst, cracking reactions occur.

[0076] The reaction vapors of hydrocarbon cracking products, unreacted feed and catalyst mixture flow rapidly through the remainder of reaction zone 262 and enter rapid separation zone 264 at the bottom of reactor / separator 260. Cracked and uncracked hydrocarbons are directed to conventional product recovery sections known in the art through conduit or pipe 270 to produce fluidized catalytic cracking products light olefins, gasoline and cycle oil with maximized propylene yield. If temperature control is required, a quench injection can be provided near the bottom of reaction zone 262 immediately before separation zone 264. The quench injection quickly reduces or stops the cracking reaction and can be used to control the severity of the cracking.

[0077] The reaction temperature, i.e., the outlet temperature of the downflow reactor, can be controlled by opening and closing a catalyst slide valve (not shown) that controls the flow of regenerated catalyst from the regeneration zone 266 to the top of the reaction zone 262. The heat required for the endothermic cracking reaction is supplied by the regenerated catalyst. By varying the flow rate of the hot regenerated catalyst, the severity of the operation or cracking conditions can be controlled to produce the desired product composition. A stripping tower 272 is also provided for separating the oil from the catalyst and transferring the catalyst to the regeneration zone 266. The catalyst from the separation zone 264 flows to the lower portion of the stripping tower 272, which includes a catalyst stripping section, into which a suitable stripping gas such as steam is introduced through flow line 274. The stripping section is typically provided with a number of baffles or structured packings (not shown), through which the downwardly flowing catalyst 280 passes in countercurrent with the flowing stripping gas. The upwardly flowing stripping gas (usually steam) is used to "strip" or remove any additional hydrocarbons retained in the catalyst pores or between the catalyst particles. The stripped or spent catalyst is transported through the riser of the regeneration zone 266 by the lift of the combustion air stream 276. The spent catalyst (which may also be contacted with additional combustion air) undergoes controlled combustion of any accumulated coke. Flue gas is removed from the regenerator via conduit 278. In the regenerator, the heat generated by the combustion of the byproduct coke is transferred to the catalyst, thereby raising the temperature required to provide heat for the endothermic cracking reactions in the reaction zone 262. According to the process herein, since the light solvent feedstock is combined with the heavy feedstock as the feed 236, the solvent to oil ratio in the initial solvent deasphalting / demetallization process is selected to provide sufficient coking of the catalyst to provide heat balance during regeneration.

[0078] Important properties of downflow reactors include introduction of feed at the top of the reactor in a downward flow, short residence time compared to riser reactors, and high catalyst to oil ratios, such as in the range of about 20:1 to about 30:1. In general, suitable operating conditions for the reactor of a propylene production downflow FCC unit include: a reaction temperature of 550°C, 650°C, in certain embodiments 580°C to 630°C, and in other embodiments 590°C to 620°C; 1 kg / cm 2 Up to 20kg / cm 2 , in certain embodiments 1 kg / cm 2 Up to 10kg / cm 2 , in another embodiment about 1 kg / cm 2 About 3kg / cm 2reaction pressure; 0.1 second to 30 seconds, in certain embodiments 0.1 second to 10 seconds, and in other embodiments 0.2 seconds to 0.7 seconds contact time (in the reactor); 1:1 to 40:1, in certain embodiments 1:1 to 30:1, and in other embodiments 10:1 to 30:1 catalyst to feed ratio.

[0079] For the sake of clarity, in the foregoing description of the FCC unit, many valves, temperature sensors, electronic process controllers and other commonly used instruments known to those of ordinary skill in the field of solvent deasphalting / demetallization and fluid catalytic cracking are not included in the accompanying schematic diagram. Auxiliary systems used in conventional fluid catalytic cracking systems, such as air supply, catalyst hoppers, combustion oil supply, flue gas treatment and heat recovery, fresh and spent catalyst hoppers for storing make-up and spent / balance catalyst that can be added to or removed from the regenerator are not shown.

[0080] Example

[0081]

[0013] The embodiments described in this disclosure will be better understood by reference to the following examples, which are provided by way of illustration, and those skilled in the art will recognize that these examples are not meant to be limiting.

[0082] The unconverted hydrocracking bottoms stream (whose properties and composition are shown in Table 1) was catalytically cracked in a MAT (microactivity test) unit under the same conditions at 550°C, a residence time of 30 seconds and a catalyst to oil ratio of 4:1 using three different catalyst systems as a basis for comparison. As in Example 1 (comparative), the catalyst system included a (Ti,Zr)-USY type zeolite catalyst without a catalyst additive. As in Example 2, the catalyst system included (Ti,Zr)-*BEA as the only zeolite catalyst without additional additives. As in Example 3, the catalyst system was a mixture of the (Ti,Zr)-USY type zeolite catalyst of Example 1 and the (Ti,Zr)-*BEA type zeolite of Example 2 as a catalyst additive, wherein the weight ratio of (Ti,Zr)-USY to (Ti,Zr)-*BEA was 9:1. The results of the three experiments are provided in Table 2.

[0083] Table 1: Properties and composition of the unconverted bottoms stream

[0084]

[0085] Table 2: Cracking compositions produced by different catalyst systems

[0086]

[0087] Example 1 demonstrates the performance of a common FCC catalyst optimized for maximum propylene yield. With only a (Ti,Zr)-USY type zeolite catalyst, the propylene yield was 2.65 wt%. Example 2 demonstrates the performance of a (Ti,Zr)-*BEA type zeolite as the sole catalytic zeolite according to an embodiment of the present disclosure. The (Ti,Zr)-*BEA type zeolite propylene yield was 2.56 wt%, almost the same as a conventional (Ti,Zr)-USY type zeolite catalyst. Example 3 demonstrates a synergistic combination of a conventional (Ti,Zr)-USY catalyst and a (Ti,Zr)-*BEA type zeolite as a catalyst additive, showing a four-fold increase in propylene yield to 11 wt%. Therefore, it is believed that the (Ti,Zr)-*BEA type zeolite according to an embodiment of the present disclosure, in addition to being an acceptable catalyst by itself, produces particularly promising propylene yields when included with a conventional FCC catalyst.

[0088] Project List

[0089] Embodiments of the present disclosure include at least the following items, which are not intended to limit the scope of the present disclosure as a whole or the appended claims.

[0090] Item 1: A method for cracking hydrocarbon oil, the method comprising: contacting the hydrocarbon oil with a catalyst system in a fluid catalytic cracking unit to produce light olefins and gasoline fuel, wherein: the catalyst system comprises an FCC alkaline catalyst and a catalyst additive; the FCC alkaline catalyst comprises a Y-type zeolite; the catalyst additive comprises a framework-substituted *BEA-type zeolite; and the framework-substituted *BEA-type zeolite has a modified *BEA framework, the modified *BEA framework comprising a *BEA aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the *BEA aluminosilicate framework with β-zeolite Al-substituent atoms, the β-zeolite Al-substituent atoms being independently selected from titanium atoms, zirconium atoms and hafnium atoms.

[0091] Item 2: The method according to Item 1, wherein the framework-substituted *BEA-type zeolite contains 0.01% to 5% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite.

[0092] Item 3: A method according to Item 1 or Item 2, wherein: based on the total mass of the framework-substituted *BEA type zeolite, calculated on an oxide basis, the framework-substituted *BEA type zeolite contains 0.01 wt% to 5 wt% of substituted atoms; and the β-zeolite Al-substituted atoms include those selected from (a) titanium atoms and zirconium atoms, (b) titanium atoms and hafnium atoms, (c) zirconium atoms and hafnium atoms, and (d) a combination of titanium atoms, zirconium atoms and hafnium atoms.

[0093] Item 4: A method according to any one of Items 1-3, wherein: based on the total mass of the framework-substituted *BEA type zeolite, calculated on an oxide basis, the framework-substituted *BEA type zeolite contains 0.01% to 5% of β-zeolite Al-substituted atoms; and the β-zeolite Al-substituted atoms include titanium atoms and zirconium atoms.

[0094] Item 5: The method according to any one of Items 1 to 4, wherein the framework-substituted *BEA zeolite has: (a) a specific surface area of ​​400 m 2 / g-800m 2 / g; (b) the molar ratio of SiO2 to Al2O3 is 10-200; (c) the pore volume is 0.2cm 3 / g-0.6cm 3 / g; and (d) lattice constants a = 1.260nm-1.270nm, b = 1.260nm-1.270nm, and c = 2.620nm-2.650nm.

[0095] Item 6: The method according to any one of Items 1-5, wherein the weight ratio of the FCC base catalyst to the catalyst additive in the catalyst system is 2:1 to 1,000:1 based on the combined weight of the FCC base catalyst and the catalyst additive.

[0096] Item 7: The method according to any one of Items 1 to 6, wherein the weight ratio of the FCC basic catalyst to the catalyst additive in the catalyst system is 4:1 to 100:1 based on the combined weight of the FCC basic catalyst and the catalyst additive.

[0097] Item 8: The method according to any one of Items 1 to 7, wherein the weight ratio of the FCC basic catalyst to the catalyst additive in the catalyst system is 6:1 to 20:1 based on the combined weight of the FCC basic catalyst and the catalyst additive.

[0098] Item 9: The method according to any one of Items 1 to 8, wherein the catalyst system comprises the FCC alkaline catalyst, the catalyst additive, a catalyst matrix carrier, a binder and a filler.

[0099] Item 10: A method according to Item 9, wherein: the catalyst matrix carrier comprises alumina or silica-alumina; the binder is a sol of a porous inorganic oxide, the porous inorganic oxide is selected from alumina, silica, boron oxide, chromium oxide, magnesium oxide, zirconium oxide, titanium dioxide, silica-alumina and combinations thereof; and the filler is a clay selected from kaolin, montmorillonite, halloysite, bentonite and combinations thereof.

[0100] Item 11: The method according to Item 9 or Item 10, wherein the catalyst system comprises, based on the total weight of the catalyst system: 1 wt% to 50 wt% of an FCC basic catalyst; 1 wt% to 50 wt% of a catalyst additive; 0.1 wt% to 15 wt% of a binder; and 0.1 wt% to 15 wt% of clay.

[0101] Item 12: The method according to any one of Items 1 to 11, wherein the weight ratio of the FCC basic catalyst to the catalyst additive in the catalyst system is 6:1 to 20:1 based on the combined weight of the FCC basic catalyst and the catalyst additive.

[0102] Item 13: The method according to any one of items 1 to 12, wherein the framework-substituted *BEA-type zeolite has mesopores with a diameter of 2 nm to 100 nm.

[0103] Item 14: The method according to any one of Items 1 to 13, wherein the Y-type zeolite comprises an ultrastable Y-type zeolite or a framework-substituted ultrastable Y-type zeolite.

[0104] Item 15: A method according to any one of Items 1 to 14, wherein: the FCC alkaline catalyst comprises a framework-substituted ultrastable Y (USY) type zeolite; and the framework-substituted USY type zeolite has a modified USY framework, the modified USY framework comprising a USY aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the USY aluminosilicate framework with USY-zeolite Al-substitution atoms, the USY-zeolite Al-substitution atoms being independently selected from titanium atoms, zirconium atoms, hafnium atoms and combinations thereof.

[0105] Item 16: The method according to Item 14 or Item 15, wherein the framework-substituted ultra-stable Y-type zeolite contains 0.01% to 5% of USY-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted ultra-stable Y-type zeolite.

[0106] Item 17: A method according to any one of Items 14 to 16, wherein the framework-substituted ultrastable Y-type zeolite has: (a) lattice constants a and b of 2.430 nm to 2.460 nm; (b) a specific surface area of ​​600 m 2 / g-900m 2 / g; and (c) a molar ratio of SiO2 to Al2O3 of 5:1 to about 100:1.

[0107] Item 18: A method according to any one of Items 14-17, wherein: based on the total mass of the framework-substituted *BEA type zeolite, calculated on the basis of oxides, the framework-substituted *BEA type zeolite contains 0.01% to 5% of β-zeolite Al-substituted atoms; the β-zeolite Al-substituted atoms include titanium atoms and zirconium atoms; based on the total mass of the framework-substituted ultra-stable Y-type zeolite, calculated on the basis of oxides, the framework-substituted ultra-stable Y-type zeolite contains 0.01% to 5% of USY-zeolite Al-substituted atoms; and the USY-zeolite Al-substituted atoms include titanium atoms and zirconium atoms.

[0108] Item 19: A method according to any one of items 1-18, wherein: the hydrocarbon oil includes hydrocarbon components with a boiling point range greater than 350°C; and the contacting occurs at a reaction temperature of 450°C to 700°C, a reaction pressure of 1 bar to 10 bar, a residence or contact time of 0.1 seconds to 60 seconds, and a catalyst to oil ratio of approximately 2:1 to 30:1.

[0109] Item 20: The method according to any one of Items 1 to 19, wherein the fluid catalytic cracking unit comprises a riser reactor or a downcomer reactor.

[0110] Item 21: A method according to any one of Items 1 to 20, wherein the framework-substituted β-type zeolite catalyst additive is a (Ti, Zr)-*BEA type zeolite having (a) a specific surface area of ​​400 m 2 / g-800m 2 / g; (b) a molar ratio of SiO2 to Al2O3 of 10-200; and (c) lattice constants a = 1.26nm-1.27nm, b = 1.26nm-1.27nm, and c = 2.62nm-2.65nm.

[0111] Item 22: A method according to any one of Items 1 to 20, wherein the framework-substituted *BEA zeolite catalyst additive is a (Ti, Zr)-*BEA zeolite having (a) a specific surface area of ​​400 m 2 / g-800m 2 / g; (b) the molar ratio of SiO2 to Al2O3 is 50-60; (c) the pore volume is 0.38cm 3 / g-0.43cm 3 / g; and (d) lattice constants a = 1.26nm-1.27nm, b = 1.26nm-1.27nm, and c = 2.62nm-2.65nm.

[0112] Item 23: A method according to any one of Items 1 to 22, wherein the catalyst system further comprises an active metal component, and the active metal component comprises iron, cobalt, nickel, rhodium, palladium, silver, iridium, platinum, gold, chromium, molybdenum or tungsten.

[0113] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those of ordinary skill in the art to which the invention belongs. The terms used in the specification of this article are only used to describe specific embodiments and are not intended to be limiting. As used in the specification and the appended claims, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise.

[0114] For the purposes of describing and defining the present disclosure, it is noted that the term "about" is used herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term "about" is also used herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0115] It should be noted that one or more of the following claims utilize the term "wherein" as a transitional phrase. For purposes of defining the present technology, it should be noted that this term is introduced in the claims as an open transitional phrase that is used to introduce a recitation of a series of features of a structure and should be interpreted in a manner similar to the more commonly used open-ended term "comprising."

[0116] It should be understood that any two quantitative values ​​assigned to a property may constitute a range for that property, and that all combinations of ranges formed by all of the stated quantitative values ​​for a given property are contemplated herein.

[0117] Although specific embodiments have been shown and described herein, it should be understood that various other changes and modifications may be made without departing from the scope of the claimed subject matter. In addition, although various aspects of the claimed subject matter have been described herein, these aspects do not need to be used in combination. Therefore, the appended claims are intended to cover all such changes and modifications within the scope of the claimed subject matter.

Claims

1. A method for cracking a hydrocarbon oil, the method comprising: contacting the hydrocarbon oil with a catalyst system in a fluid catalytic cracking unit to produce light olefins and gasoline fuel, in: The catalyst system includes an FCC basic catalyst and a catalyst additive; The FCC basic catalyst comprises Y-type zeolite; The catalyst additive includes a framework-substituted *BEA-type zeolite; and The framework-substituted *BEA-type zeolite has a modified *BEA framework, wherein the modified *BEA framework includes a *BEA aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the *BEA aluminosilicate framework with β-zeolite Al-substituent atoms, wherein the β-zeolite Al-substituent atoms are independently selected from titanium atoms, zirconium atoms, hafnium atoms and combinations thereof.

2. The method according to claim 1, wherein: The framework-substituted *BEA-type zeolite contains from 0.01% to 5% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite.

3. The method according to claim 1, wherein: The framework-substituted *BEA-type zeolite contains 0.01 wt % to 5 wt % of substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite; and The Al-substituted atoms of β-zeolite include atoms selected from the group consisting of (a) titanium atoms and zirconium atoms, (b) titanium atoms and hafnium atoms, (c) zirconium atoms and hafnium atoms, and (d) a combination of titanium atoms, zirconium atoms and hafnium atoms.

4. The method according to claim 1, wherein: The framework-substituted *BEA-type zeolite contains from 0.01% to 5% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite; and The Al-substituted atoms of β-zeolite include titanium atoms and zirconium atoms.

5. The method according to claim 1, wherein: The framework-substituted *BEA zeolite has: (a) Specific surface area is 400m 2 / g-800m 2 / g; (b) the molar ratio of SiO2 to Al2O3 is 10-200; (c) Pore volume 0.2 cm 3 / g-0.6cm 3 / g; and (d) Lattice constants a = 1.260 nm - 1.270 nm, b = 1.260 nm - 1.270 nm, and c = 2.620 nm - 2.650 nm.

6. The method according to any one of claims 1 to 5, wherein: The weight ratio of the FCC base catalyst to the catalyst additive in the catalyst system is 2:1 to 1,000:1 based on the combined weight of the FCC base catalyst and the catalyst additive.

7. The method according to claim 1, wherein: The catalyst system includes the FCC basic catalyst, the catalyst additive, a catalyst matrix carrier, a binder and a filler.

8. The method according to claim 7, wherein: The catalyst matrix carrier comprises alumina or silica-alumina; The binder is a sol of a porous inorganic oxide, wherein the porous inorganic oxide is selected from alumina, silica, boria, chromia, magnesia, zirconia, titania, silica-alumina and combinations thereof; and The filler is clay selected from kaolin, montmorillonite, halloysite, bentonite and combinations thereof.

9. The method according to claim 8, wherein: Based on the total weight of the catalyst system, the catalyst system comprises: 1 wt % to 50 wt % of an FCC basic catalyst; 1 wt % to 50 wt % of a catalyst additive; 0.1 wt % to 15 wt % of a binder; and 0.1 wt% to 15 wt% clay.

10. The method according to claim 1, wherein: The weight ratio of the FCC base catalyst to the catalyst additive in the catalyst system is 6:1 to 20:1 based on the combined weight of the FCC base catalyst and the catalyst additive.

11. The method according to claim 1, wherein: The FCC basic catalyst comprises a framework-substituted ultrastable Y (USY) type zeolite; and The framework-substituted USY-type zeolite has a modified USY framework, and the modified USY framework includes a USY aluminosilicate framework modified by replacing a portion of the framework aluminum atoms of the USY aluminosilicate framework with USY-zeolite Al-substituent atoms, and the USY-zeolite Al-substituent atoms are independently selected from titanium atoms, zirconium atoms, hafnium atoms and combinations thereof.

12. The method according to claim 11, wherein: The framework-substituted ultrastable Y-zeolite contains 0.01% to 5% of USY-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted ultrastable Y-zeolite.

13. The method according to claim 11, wherein: The framework-substituted ultrastable Y-type zeolite has: (a) Lattice constants a and b are 2.430nm-2.460nm; (b) Specific surface area is 600m 2 / g-900m 2 / g; and (c) The molar ratio of SiO2 to Al2O3 is 5:1 to 100:

1.

14. The method according to any one of claims 11 to 13, wherein: The framework-substituted *BEA-type zeolite contains from 0.01% to 5% of β-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted *BEA-type zeolite; The Al-substituted atoms of the β-zeolite include titanium atoms and zirconium atoms; The framework-substituted ultrastable Y-zeolite contains from 0.01% to 5% of USY-zeolite Al-substituted atoms, calculated on an oxide basis, based on the total mass of the framework-substituted ultrastable Y-zeolite; and The USY-zeolite Al-substituting atoms include titanium atoms and zirconium atoms.

15. The method of claim 1, wherein: The hydrocarbon oil includes hydrocarbon components having a boiling point range greater than 350°C; and The contacting occurs at a reaction temperature of 450°C to 700°C, a reaction pressure of 1 bar to 10 bar, a residence or contact time of 0.1 seconds to 60 seconds, and a catalyst to oil weight ratio of 2:1 to 30:1.

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