Catalytic cracking aid and preparation method thereof

Abstract

The preparation method specifically comprises the following steps: (1) pulping waste residues of a catalytic reforming catalyst containing noble metal to obtain slurry with the solid content of 5wt%-15wt%; (2) levigating the slurry, and controlling the granularity D (V, 0.5) to be less than or equal to 1 mu m and D (V, 0.9) to be less than or equal to 3 mu m, so as to obtain levigated slurry; (3) mixing and pulping the ground slurry, modified aluminum oxide and a binder to obtain mixed slurry, and performing spray drying; the modified aluminum oxide is prepared from the following components in percentage by weight: 50 to 95 percent of aluminum oxide and 5 to 50 percent of active metal; and the active metal is selected from one or more of Fe, Co, Mn, Mg, Cu and Zr.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid catalytic cracking, and particularly relates to a fluid catalytic cracking promoter and a preparation method thereof. Background Art

[0002] In the process of fluid catalytic cracking (FCC), the feedstock oil and the regenerated catalyst quickly contact in the riser to carry out the catalytic cracking reaction. The coke generated by the reaction deposits on the catalyst, causing its inactivation. The coked and inactivated catalyst enters the regenerator after stripping, and contacts with the regenerated air or oxygen-rich air entering from the bottom of the regenerator for coke burning and regeneration. The regenerated catalyst is recycled back to the reactor to participate in the catalytic cracking reaction again. According to the excess oxygen content in the flue gas during the regeneration process or the degree of CO oxidation, the fluid catalytic cracking unit can be divided into complete regeneration and incomplete regeneration operations. During the complete regeneration process, the coke and the nitrogen-containing compounds in the coke generate CO2 and N2 under the action of the regenerated air, and at the same time, pollutants such as CO and NOx are also generated.

[0003] The promoter used to reduce the CO emission in the regenerated flue gas is usually called a CO combustion promoter. For example, CN1022843C discloses a noble metal-supported carbon monoxide combustion promoter, the active component of which is 1-1000 ppm of platinum or 50-1000 ppm of palladium, and the carrier is composed of (1) 99.5-50% of microspherical particles of a cracking catalyst or its matrix and (2) 0.5-50% of Al2O3, 0-20% of RE2O3 and 0-15% of ZrO2, and (2) is the outer coating of the (1) particles. However, this type of promoter usually causes a huge increase in NOx in the flue gas.

[0004] The promoter used to control the NOx emission in the flue gas is usually called a NOx emission reduction promoter or a NOx reduction promoter. For example, CN102371150A discloses a non-noble metal composition for reducing the NOx emission in the fluid catalytic cracking regenerated flue gas. The bulk ratio of the composition does not exceed 0.65 g / ml. Based on the weight of the composition, it contains, in terms of oxides: (1) 50-99 wt% of an inorganic oxide carrier, (2) 0.5-40 wt% of one or more non-noble metal elements selected from Groups IIA, IIB, IVB and VIB, and (3) 0.5-30 wt% of rare earth elements. The composition is used for fluid catalytic cracking and can significantly reduce the NOx emission in the regenerated flue gas.

[0005] There is also a type of promoter that can simultaneously reduce the emissions of CO and NOx in the regenerated flue gas, which can take into account both CO combustion promotion and NOx emission reduction. With the increasingly strict environmental protection regulations, the application of this type of promoter is becoming increasingly common. For example, CN1688508A discloses a composition for reducing NOx and CO emissions in the flue gas of fluid catalytic cracking and its application. The composition includes copper and / or cobalt and a carrier, and the carrier is selected from hydrotalcite-like compounds, spinels, alumina, zinc titanate, zinc aluminate, zinc titanate / zinc aluminate. CN102371165A discloses a low bulk ratio composition for reducing CO and NOx emissions in the FCC regenerated flue gas. This composition contains rare earth elements and one or several non-noble metal elements, and preferably the non-noble metal is loaded on Y-type zeolite. US6165933 discloses a CO combustion promoter composition (promoter) for reducing NOx emissions in the catalytic cracking process. The composition includes: (i) an acidic metal oxide substantially free of zeolite in the specification, page 1 / 17, CN109201080A; (ii) an alkali metal, an alkaline earth metal, or a mixture thereof; (iii) an oxygen storage component; and (iv) palladium. The inorganic oxide carrier is preferably silica-alumina, and the oxygen storage transition metal oxide is preferably cerium oxide. US7045056 discloses a composition for simultaneously reducing CO and NOx emissions in the flue gas during the catalytic cracking process. The composition includes: (i) an inorganic oxide carrier; (ii) an oxide of cerium; (iii) a lanthanide oxide other than cerium, where the weight ratio of (ii) to (iii) is at least 1.66:1; (iv) optionally a transition metal oxide of Group IB and IIB; and (v) at least one noble metal element. CN105363444A discloses a composition for reducing CO and NOx emissions in the FCC regenerated flue gas and its preparation method. The composition contains, in terms of oxides: (1) 0.5-30 wt% of rare earth elements, (2) 0.01-0.15 wt% of noble metal elements, and (3) the balance of an inorganic oxide carrier substantially free of alkali metals and alkaline earth metals. In its preparation method, the composition after introducing the noble metal is treated with an alkaline solution before drying and / or calcination. The disclosed composition is used for fluid catalytic cracking, can effectively avoid "afterburning" caused by too high a CO concentration in the regenerated flue gas, can effectively control the emission concentrations of CO and NOx in the regenerated flue gas, significantly reduce the NOx emissions in the flue gas, and basically has no adverse impact on the FCC product distribution. Summary of the Invention

[0006] The present invention provides a preparation method of a catalytic cracking promoter, and the method includes the following steps:

[0007] (1) Pulping the catalytic reforming catalyst waste residue containing noble metals to obtain a slurry; preferably, the solid content of the slurry is 5 wt% to 15 wt%;

[0008] (2) The slurry is ground to control the particle size to be D(V, 0.5) ≤ 1 μm and D(V, 0.9) ≤ 3 μm, thereby obtaining a ground slurry;

[0009] (3) mixing and beating the ground slurry, modified alumina, and a binder to obtain a mixed slurry, and spray drying;

[0010] The composition of the modified alumina includes: an alumina content of 50wt% to 95wt%, preferably, the alumina content is 65wt% to 95wt%, more preferably, the alumina content is 50wt% to 80wt%, and further preferably, the alumina content is 50wt% to 70wt%; an active metal content of 5wt% to 35wt%, preferably, the active metal content is 10wt% to 50wt%, more preferably, the active metal content is 20wt% to 35wt%; the active metal is selected from one or more of Fe, Co, Mn, Mg, Cu, and Zr; preferably, one or more of Fe, Co, Mn, and Mg.

[0011] In one embodiment, the noble metal is selected from one or both of Pt and Pd.

[0012] In one embodiment, in the waste residue, based on dry weight, the Al2O3 content is 90 wt% to 99 wt%, the precious metal content is 0.01 wt% to 0.5 wt%, and the SiO2 content is 0.01 wt% to 10 wt%.

[0013] In one embodiment, the modified alumina further comprises: a sodium oxide content of 0.01 wt% to 1.0 wt% and a silicon dioxide content of 0.01 wt% to 3 wt%.

[0014] In one embodiment, the pore volume of the modified alumina is 0.4 mL / g to 1.0 mL / g, and the specific surface area is 100 m 2 / g~300m 2 / g.

[0015] In one embodiment, a method for preparing modified alumina comprises:

[0016] A method for preparing modified alumina comprises:

[0017] S1, calcining aluminum hydroxide at a temperature of 500° C. to 800° C.;

[0018] S2. Slurrying the calcined aluminum hydroxide to obtain an aluminum hydroxide slurry, wherein the solid content of the aluminum hydroxide slurry is controlled to be 10 wt% to 30 wt%;

[0019] S3. Add hydrochloric acid, adjust the pH to 4 - 6, filter, dry, and calcine to obtain alumina;

[0020] S4. Supersaturate and impregnate the alumina obtained in step S3 with a mixed salt solution of active metals, dry, and calcine to obtain modified alumina.

[0021] In one embodiment, in step S3, the drying temperature is 100°C - 300°C; the calcination temperature is 450°C - 650°C, and the calcination time is 1h - 3h.

[0022] In one embodiment, in step S4, the drying temperature is 100°C - 300°C; the calcination temperature is 500°C - 800°C, and the time is 1h - 3h.

[0023] In one embodiment, in step S4, the mixed salt of active metals is one or more of nitrates, hydrochlorides, and organic salts.

[0024] In one embodiment, in step (3), the binder is pseudoboehmite, or a composition of pseudoboehmite and aluminum sol.

[0025] In one embodiment, in step (3), the preparation method of the binder includes:

[0026] S01. Pulp pseudoboehmite with water, and control the solid content of the slurry to be 5 - 10%;

[0027] S02. Add acid to adjust the pH to 1 - 2.5;

[0028] S03. Age at a temperature of 50°C - 90°C for 1h - 5h;

[0029] S04. Add ammonia water to adjust the pH to 3.5 - 5.5.

[0030] In one embodiment, in step S02, the acid is one or more of organic acids and inorganic acids; among them, the organic acid is one or more of formic acid, acetic acid, and oxalic acid, and the inorganic acid is one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0031] In one embodiment, in step S03, it further includes adding aluminum sol before the aging treatment.

[0032] In one embodiment, in step (3), the spray drying temperature is 180°C - 250°C.

[0033] Another object of the present invention is to provide an auxiliary agent prepared by the above method.

[0034] In one embodiment, the composition of the auxiliary agent is as follows: the content of waste residue is 5wt% - 30wt%, the content of modified alumina is 10wt% - 50wt%, and the content of binder is 40wt% - 70wt%.

[0035] Another object of the present invention is to provide the application of the above auxiliary agent in reducing the CO concentration in the flue gas of catalytic cracking regeneration while controlling the NO X emission.

[0036] Beneficial effects:

[0037] 1. The present invention directly uses the waste residue of the catalytic reforming catalyst containing noble metals as the raw material, and only needs to carry out pulp grinding treatment on the waste residue. The preparation process is simple, the operation is convenient, and it is easy to industrialize, realizing the green utilization of the waste residue of the catalytic reforming catalyst.

[0038] 2. The present invention provides an auxiliary agent prepared by combining the waste residue of the catalytic reforming catalyst containing noble metals with the modified alumina containing transition metals and a binder prepared by a specific method, which can promote CO oxidation and NOx reduction at the same time. The three work together synergistically to achieve the purpose of reducing the CO concentration in the flue gas while still controlling the NOx emission. Through the variable regulation of different components, the flexible control of CO combustion promotion activity and NOx emission can be realized. The present invention can directly recycle the waste catalyst containing noble metals, reduce the steps of noble metal extraction and reuse, and realize the secondary utilization of waste catalyst resources. Specific embodiments

[0039] The following further illustrates the technical solutions of the present disclosure according to specific embodiments. The protection scope of the present disclosure is not limited to the following embodiments. These examples are listed for illustrative purposes only and do not limit the present disclosure in any way.

[0040] The present invention provides a preparation method of a catalytic cracking auxiliary agent, which is characterized in that the method comprises the following steps:

[0041] (1) Pulping the waste residue of the catalytic reforming catalyst containing noble metals to obtain a slurry; preferably, the solid content of the slurry is 5wt% - 15wt%;

[0042] (2) Subjecting the slurry to grinding treatment to control the particle size to D(V,0.5) ≤ 1μm and D(V,0.9) ≤ 3μm to obtain the ground slurry;

[0043] (3) Mixing and pulping the ground slurry, modified alumina and binder to obtain a mixed slurry, and spray drying;

[0044] The composition of the modified alumina includes: the alumina content is 50 wt% to 95 wt%, preferably, the alumina content is 65 wt% to 95 wt%, more preferably, the alumina content is 50 wt% to 80 wt%, and further preferably, the alumina content is 50 wt% to 70 wt%; the active metal content is 5 wt% to 50 wt%, preferably, the content of the active metal is 10 wt% to 35 wt%, more preferably, the content of the active metal is 20 wt% to 35 wt%; the active metal is selected from one or more of Fe, Co, Mn, Mg, Cu, and Zr; preferably, it is one or more of Fe, Co, Mn, and Mg.

[0045] Among them, the grinding method is not specifically limited and can be ball milling, jet milling, etc.

[0046] The catalytic reforming catalyst waste residue is the gum residue generated during the production of the catalytic reforming catalyst.

[0047] Through the grinding treatment, the particle size of the waste residue slurry is controlled to D(V,0.5) ≤ 1 μm and D(V,0.9) ≤ 3 μm. If the particle size is too large, it will not be evenly mixed with the modified alumina and the binder, resulting in a small specific surface area and unstable performance of the final product.

[0048] The particle size in the present invention is obtained by testing according to the standard NB / SH / T 0951-2017.

[0049] In one embodiment, the waste residue contains precious metals, and the precious metals are selected from one or two of Pt and Pd.

[0050] In one embodiment, in the waste residue, based on the dry basis weight, the Al2O3 content is 90 wt% to 99 wt%, such as 94.5 to 98 wt%; the content of the precious metal is 0.01 wt% to 0.5 wt%, and the SiO2 content is 0.01 wt% to 10 wt%, such as 0.01 wt% to 5 wt%.

[0051] In one embodiment, the waste residue contains one or more other metals such as Zr, Re, and Sn; the content of the other metal is 0.1 wt% to 3 wt%.

[0052] In one embodiment, the pore volume of the modified alumina is 0.4 mL / g to 1.0 mL / g, and the specific surface area is 100 m 2 / g to 300 m 2 / g.

[0053] In one embodiment, the modified alumina contains impurity sodium oxide and silica, and the impurity content is controlled within the following ranges: the sodium oxide content is 0.01 wt% to 1.0 wt%, and the silica content is 0.01 wt to 3 wt%. If the contents of sodium oxide and silica are higher than the above ranges, it will affect the removal performance of CO and NO x of the catalytic cracking promoter.

[0054] In one embodiment, the preparation method of the modified alumina includes:

[0055] S1. Calcining aluminum hydroxide, and the calcination temperature is 500°C to 800°C;

[0056] S2. Pulping the calcined aluminum hydroxide to obtain an aluminum hydroxide slurry, and controlling the solid content of the aluminum hydroxide slurry to be 10% to 30%;

[0057] S3. Adding hydrochloric acid, adjusting the pH to 4 to 6, filtering, drying, and calcining to obtain alumina;

[0058] S4. Supersaturating and impregnating the alumina obtained in step S3 with a salt solution of an active metal, drying, and calcining to obtain modified alumina.

[0059] In the technical solution of the present invention, by adopting a specific method (calcining twice successively and controlling the calcination temperature, adding acid to adjust the pH during the preparation process, and modifying with an active metal), the preparation of modified alumina is facilitated, which helps to promote its synergistic effect with the pretreated waste residue and binder, helps to promote its reduction of the CO concentration in the flue gas, and controls the NOx emission.

[0060] In one embodiment, in step S3, the drying temperature is 100°C to 300°C; the calcination temperature is 450°C to 650°C, and the calcination time is 1 h to 3 h.

[0061] In one embodiment, in step S4, the drying temperature is 100°C to 300°C; the calcination temperature is 500 to 800°C, and the time is 1 to 3 h.

[0062] In one embodiment, in step S4, the salt of the active metal is one or more of nitrates, hydrochlorides, and organic salts.

[0063] In one embodiment, in step (3), the binder is pseudoboehmite, or a composition of pseudoboehmite and aluminosol.

[0064] In one embodiment, in step (3), the preparation method of the binder includes:

[0065] S01. Slurry boehmite with water and control the solid content of the slurry to be 5-10%.

[0066] S02. Add acid to adjust the pH to 1-2.5.

[0067] S03. Age at a temperature of 50°C - 90°C for 1h - 5h.

[0068] S04. Add ammonia water to adjust the pH to 3.5 - 5.5.

[0069] The binder of the present invention is prepared by a method of first acidifying and then adjusting with ammonia water. Compared with the binders in the prior art (such as boehmite, aluminosol or their mixtures), it can cooperate with the waste residue and modified alumina of the present invention to promote the conversion of CO and the concentration control of NOx in catalytic cracking flue gas.

[0070] In one embodiment, in step S02, the acid is one or more of organic acids and inorganic acids; wherein, the organic acids are one or more of formic acid, acetic acid, and oxalic acid, and the inorganic acids are one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0071] In one embodiment, in step S03, it further includes adding aluminosol before the aging treatment. Preferably, the mass ratio of boehmite to aluminosol is 1 - 5:1.

[0072] The binder is further preferably a composition of boehmite and aluminosol prepared by the above method. Compared with single boehmite, it is more conducive to the mixing of the pretreated waste residue and modified alumina, helps to promote the reduction of CO concentration in the product additive and control the effect of NOx emission, and at the same time improves the abrasion resistance.

[0073] In one embodiment, in step (3), the temperature of spray drying is 180°C - 250°C.

[0074] Another object of the present invention is to provide an additive prepared by the above method.

[0075] In one embodiment, the composition of the additive is: the content of waste residue is 5wt% - 30wt%, the content of modified alumina is 10wt% - 50wt%, and the content of binder is 40wt% - 70wt%.

[0076] Another object of the present invention is to provide the above additive for reducing the CO concentration in catalytic cracking regeneration flue gas while controlling NO X emission. Specific embodiments

[0078] The present invention will be further illustrated by the following examples, but the present invention is not limited thereby.

[0079] Waste residue 1#: Na2O 0.0155 wt%, Al2O3 95.5 wt%, SiO2 0.577 wt%, Fe2O3 0.636 wt%, CeO2 0.461 wt%, PtO2 0.398 wt% (Pt 0.342 wt%), ZrO2 0.391 wt%, solid content 95 wt%, from Sinopec Catalyst Co., Ltd.;

[0080] Pseudoboehmite is produced by Aluminum Corporation of China, with a solid content of 62.0 wt%;

[0081] Hydrochloric acid is produced by Beijing Chemical Plant, with an analytical purity specification and a mass concentration of 36%;

[0082] Aluminum sol is produced by Sinopec Catalyst Co., Ltd., with an alumina content of 21.5 wt%;

[0083] Aluminum hydroxide is produced by Aluminum Corporation of China, with an alumina content of 64.0 wt%;

[0084] The specific surface area is analyzed by the method of NB / SH / T 0959 - 2017;

[0085] Magnesium chloride is produced by Beijing Chemical Plant, with an analytical purity specification;

[0086] Cobalt chloride is produced by Beijing Chemical Plant, with an analytical purity specification;

[0087] Manganese chloride is produced by Beijing Chemical Plant, with an analytical purity specification;

[0088] Iron chloride is produced by Beijing Chemical Plant, with an analytical purity specification;

[0089] The sample composition is determined by X-ray fluorescence spectrometry (XRF);

[0090] The apparent bulk density of the fluid catalytic cracking catalyst is determined by NB / SH / T 0954 - 2017;

[0091] The pore volume of the fluid catalytic cracking catalyst by the water drop method is determined by NB / SH / T 0955 - 2017;

[0092] The attrition index of the fluid catalytic cracking catalyst is determined by NB / SH / T 0964 - 2017;

[0093] The particle size of the waste residue slurry is determined by NB / SH / T 0951 - 2017.

[0094] Example 1

[0095] 1) Slurry the waste residue 1# with deionized water under high-speed stirring conditions, evenly control the solid content to 15 wt%, and obtain the colloidal residue slurry after ball milling, where D(V, 0.5) is 0.9 microns and D(V, 0.9) is 2.9 microns;

[0096] 2) Calcinate aluminum hydroxide at 800 °C for 3 hours, then slurry it, control the solid content of the slurry to 20 wt%, add hydrochloric acid, adjust the pH to 5.0, filter, dry at 150 °C, and calcine at 550 °C for 2 hours to obtain alumina;

[0097] 3) Impregnate alumina with a mixed metal salt solution (an aqueous solution containing magnesium chloride, iron chloride, cobalt chloride, and manganese chloride). Calculated by the mass of oxides (the same below), alumina (calculated as Al2O3): magnesia (calculated as MgO): iron oxide (calculated as Fe2O3): cobalt oxide (calculated as Co2O3): manganese oxide (calculated as MnO2) = 60:10:10:8:3. Dry at 150 °C and calcine at 700 °C for 2 hours to obtain modified alumina. The specific surface area is 148.7 m 2 / g, the pore volume is 0.51 ml / g, where the sodium oxide content is 0.11 wt% and the silica content is 0.5 wt%. Slurry the alumina in deionized water to prepare a modified alumina slurry with a solid content of 20 wt%;

[0098] 4) Slurry pseudo-boehmite with water, control the solid content of the slurry to 10 wt%, add acid to adjust the pH to 2.5, age at 80 °C for 2 h, and add ammonia water to adjust the pH to 5 to obtain a binder with a final solid content of 12 wt%;

[0099] 5) Mix the above three solutions according to the ratio in Table 1, stir for 30 min to obtain a mixed slurry, and prepare the additive Z1 by spray drying.

[0100] Example 2

[0101] 1) Slurry the waste residue 1# with deionized water under high-speed stirring conditions, evenly control the solid content to 15 wt%, and obtain the colloidal residue slurry after ball milling, where D(V, 0.5) is 0.9 microns and D(V, 0.9) is 2.9 microns;

[0102] 2) Calcinate aluminum hydroxide at 800 °C for 3 hours, then slurry it, control the solid content of the slurry to 20 wt%, add hydrochloric acid, adjust the pH to 5.0, filter, dry at 150 °C, and calcine at 550 °C for 2 hours to obtain alumina;

[0103] 3) The alumina is supersaturated impregnated with a mixed metal salt solution (an aqueous solution containing magnesium chloride, iron chloride, cobalt chloride, and manganese chloride). By mass of the oxides, alumina:magnesium oxide:iron oxide:cobalt oxide:manganese oxide = 60:5:5:4:1.5. It is dried at 150 °C and calcined at 700 °C for 2 hours to obtain modified alumina with a specific surface area of 188.7 m 2 / g, a pore volume of 0.62 ml / g, a sodium oxide content of 0.13 wt%, and a silica content of 0.6 wt%. The alumina is slurried in deionized water to prepare a modified alumina slurry with a solid content of 20 wt%.

[0104] 4) The pseudo-boehmite is slurried with water, the solid content of the slurry is controlled to be 10 wt%, acid is added to adjust the pH to 2.5, aged at 80 °C for 2 h, and ammonia water is added to adjust the pH to 5 to obtain a binder with a final solid content of 12 wt%.

[0105] 5) The above three solutions are mixed in the proportions in Table 1, stirred for 30 min to obtain a mixed slurry, and prepared into an additive Z2 by spray drying.

[0106] Example 3

[0107] Other conditions are the same as those in Example 1, except that the preparation of the binder is different. Specifically: The pseudo-boehmite is slurried with water, the solid content of the slurry is controlled to be 5 wt%, acid is added to adjust the pH to 2.5, and aluminum sol is added. The mass ratio of pseudo-boehmite to aluminum sol is 1:1 (calculated as alumina). It is aged at 80 °C for 2 h, and ammonia water is added to adjust the pH to 5 to obtain a modified binder with a solid content of 14 wt%, and finally an additive Z3 is prepared.

[0108] Example 4

[0109] Other conditions are the same as those in Example 1, except that the metal for modifying the alumina is Fe. By mass of the oxides, alumina:iron oxide = 60:31, with a specific surface area of 145.2 m 2 / g, a pore volume of 0.49 ml / g, a sodium oxide content of 0.16 wt%, and a silica content of 0.7 wt%. Finally, an additive Z4 is prepared.

[0110] Example 5

[0111] Other conditions are the same as those in Example 1, except that the metals for modifying the alumina are Fe and Co. By mass of the oxides, alumina:iron oxide:cobalt oxide = 82:10:8. The specific surface area of the modified alumina is 181.3 m 2 / g, a pore volume of 0.58 ml / g, a sodium oxide content of 0.13 wt%, and a silica content of 0.6 wt%. Finally, an additive Z5 is prepared.

[0112] Example 6

[0113] Other conditions are the same as those in Example 1, except that the metals for modifying alumina are Fe and Mn. By mass of the oxides, alumina: iron oxide: manganese oxide = 85:10:5, specific surface area is 174.2 m 2 / g, pore volume is 0.57 ml / g, where the sodium oxide content is 0.17 wt%, and the silicon dioxide content is 0.7 wt%. Finally, the promoter Z6 is prepared.

[0114] Example 7

[0115] Other conditions are the same as those in Example 1, except that the metals for modifying alumina are Mg, Co, and Mn. By mass of the oxides, alumina: magnesium oxide: cobalt oxide: manganese oxide = 50:11:11:9, specific surface area is 129.1 m 2 / g, pore volume is 0.44 ml / g, where the sodium oxide content is 0.14 wt%, and the silicon dioxide content is 0.6 wt%. Finally, the promoter Z7 is prepared.

[0116] Comparative Example 1

[0117] Other conditions are the same as those in Example 1, except that no waste residue is added, and the promoter DZ1 is obtained.

[0118] Comparative Example 2

[0119] 1) Pulp the waste residue 1# with deionized water under high-speed stirring to make it uniform, control the solid content to be 15 wt%, and ball mill to obtain the colloidal residue slurry, where D(V,0.5) is 0.9 microns and D(V,0.9) is 2.9 microns;

[0120] 2) Dissolve the corresponding metal chlorides according to the ratio of magnesium oxide: iron oxide: cobalt oxide: manganese oxide = 10:10:8:3 by mass of the oxides to prepare a solution with a mass concentration of 15 wt%;

[0121] 3) Slurry the pseudo-boehmite with water, control the solid content of the slurry to be 10 wt%, add acid to adjust the pH to 2.5, age at 80 °C for 2 h, and add ammonia water to adjust the pH to 5. Finally, a binder with a solid content of 12 wt% is obtained.

[0122] 4) Mix the above three solutions according to the ratio in Table 1, stir for 30 min to obtain a mixed slurry, and prepare the promoter DZ2 by spray drying.

[0123] Comparative Example 3

[0124] Other conditions are the same as those in Example 1, except that the modified alumina is replaced with commercial alumina, Al2O3 95.7%, SiO2 0.13%, Na2O 0.15%, pore volume 0.91 ml / g, specific surface area 213 m 2 / g, produced by Aluminum Corporation of China, and the specific steps are as follows:

[0125] 1) Pulp the waste residue 1# with deionized water under high-speed stirring to make it uniform, control the solid content to be 15 wt%, and obtain a colloidal residue slurry after ball milling, where D(V,0.5) is 0.9 microns and D(V,0.9) is 2.9 microns;

[0126] 2) Impregnate the commercial alumina supersaturated with metal salts. Calculated by the mass of oxides, alumina:magnesium oxide:iron oxide:cobalt oxide:manganese oxide = 60:10:10:8:3. Dry at 150 °C and calcine at 700 °C for 2 hours to obtain modified commercial alumina with a surface area of 141.2 m 2 / g and a pore volume of 0.47 ml / g;

[0127] 3) Pulp the modified commercial alumina in deionized water to prepare a slurry with a solid content of 20 wt%.

[0128] 4) Pulp the pseudo-boehmite with water, control the solid content of the slurry to be 10 wt%, add acid to adjust the pH to 2.5, age at 80 °C for 2 h, add ammonia water to adjust the pH to 5, and finally the solid content is 12 wt%.

[0129] 5) Mix the above three solutions in the proportions shown in Table 1, stir for 30 min to obtain a mixed slurry, and prepare the auxiliary agent DZ3 by spray drying.

[0130] Comparative Example 4

[0131] Other conditions are the same as those in Example 1, except that the modified alumina is replaced with commercial alumina, Al2O3 95.7%, SiO2 0.13%, Na2O 0.15%, pore volume 0.91 ml / g, specific surface area 213 m 2 / g, produced by Aluminum Corporation of China, and the specific steps are as follows:

[0132] 1) Pulp the waste residue 1# with deionized water under high-speed stirring to make it uniform, control the solid content to be 15 wt%, and obtain a colloidal residue slurry after ball milling, where D(V,0.5) is 0.9 microns and D(V,0.9) is 2.9 microns;

[0133] 2) Pulp the commercial alumina in deionized water to prepare a slurry with a solid content of 20 wt%.

[0134] 3) Dissolve the corresponding metal chlorides in proportion by mass of magnesium oxide: iron oxide: cobalt oxide: manganese oxide = 10:10:8:3 based on the mass of the oxides to prepare a solution with a mass concentration of 15 wt%.

[0135] 4) Slurry pseudoboehmite with water, control the solid content of the slurry to be 10 wt%, add acid to adjust the pH to 2.5, age at 80 °C for 2 h, add ammonia water to adjust the pH to 5, and finally the solid content is 12 wt%.

[0136] 5) Mix the above four solutions according to the proportions in Table 1, stir for 30 min to obtain a mixed slurry, and prepare the auxiliary agent DZ4 through spray drying.

[0137] Comparative Example 5 <�

[0138] Other conditions are the same as those in Example 1, the difference is that the preparation scheme of the binder is to slurry pseudoboehmite with water, control the solid content of the slurry to be 12 wt%, add acid to adjust the pH to 2.5 to obtain the binder; finally, the auxiliary agent DZ5 is prepared, and the specific steps are as follows:

[0139] 1) Slurry the waste residue 1# with deionized water under high-speed stirring to make it uniform, control the solid content to be 15 wt%, and obtain a colloidal residue slurry after ball milling, where D(V, 0.5) is 0.9 μm and D(V, 0.9) is 2.9 μm;

[0140] 2) Calcinate aluminum hydroxide at 800 °C for 3 hours, then slurry it, control the solid content of the slurry to be 20 wt%, add hydrochloric acid, adjust the pH to 5.0, filter, dry at 150 °C, and calcinate at 550 °C for 2 hours to obtain alumina;

[0141] 3) Perform supersaturated impregnation of alumina with metal salts. Based on the mass of the oxides, alumina:magnesium oxide:iron oxide:cobalt oxide:manganese oxide = 60:10:10:8:3. Dry at 150 °C and calcinate at 700 °C for 2 hours to obtain modified alumina with a specific surface area of 148.7 m 2 / g and a pore volume of 0.51 ml / g. Slurry the alumina in deionized water to prepare a modified alumina slurry with a solid content of 20 wt%;

[0142] 4) Slurry pseudoboehmite with water, control the solid content of the slurry to be 10 wt%, add acid to adjust the pH to 2.5 to obtain the binder;

[0143] 5) Mix the above three solutions according to the proportions in Table 1, stir for 30 min to obtain a mixed slurry, and prepare the auxiliary agent DZ5 through spray drying.

[0144] Table 1

[0145]

[0146] The summary of the properties of the additives prepared in Examples 1-7 and Comparative Examples 1-5 is shown in Table 2:

[0147] Table 2

[0148]

[0149]

[0150] Experimental Example 1

[0151] The additive Z1 prepared in Example 1 was uniformly blended with a fluid catalytic cracking catalyst (Cat-1 (brand G&DMAX, produced by Sinopec Catalyst Co., Ltd.), and the specific composition is shown in Table 3) at a mass ratio of 1.5:100. After aging for 12 h under an atmosphere of 800 °C and 100% steam, catalyst A1 was obtained.

[0152] Table 3 Physical property parameters of fluid catalytic cracking catalyst Cat-1

[0153]

[0154] Experimental Examples 2-7

[0155] Catalysts A2-A7 were prepared by the same method as in Experimental Example 1, except that in Experimental Examples 2-7, the additive Z2-Z7 was used in equal amounts to replace the additive Z1 in Experimental Example 1.

[0156] Comparative Experimental Examples 1-5

[0157] Fluid catalytic cracking catalysts DA1, DA2, DA3, DA4, and DA5 were prepared by the same method as in Example 1, except that in Comparative Examples 1-5, the additives DZ1, DZ2, DZ3, DZ4, and DZ5 were used in equal amounts to replace the additive Z1 in Example 1.

[0158] Test Example 1

[0159] Catalytic cracking reaction-regeneration evaluation was carried out on a small fixed fluidized bed unit. The catalyst loading was 9 g, the reaction temperature was 500 °C, the catalyst-to-oil weight ratio was 6, and the properties of the feedstock oil are shown in Table 6. The cracked gas composition of the gas products was obtained by on-line chromatographic analysis; the yields of gasoline, diesel, and heavy oil of the liquid products were obtained by off-line chromatographic analysis. After the reaction, it was stripped with N2 for 10 min and subjected to in-situ coke burning regeneration. The regeneration air flow rate was 200 mL / min, the regeneration time was 15 min, and the initial regeneration temperature was the same as the reaction temperature. The flue gas during the regeneration process was collected, and the coke yield was calculated by integrating with a CO2 infrared analyzer after the regeneration was completed. After normalizing all product yields, the FCC product distribution was obtained, as shown in Table 4. The conversion rate in Table 4 refers to the sum of the yields of dry gas, liquefied gas, gasoline, and coke. The concentrations of NO x and CO in the flue gas were measured using a Testo350Pro flue gas analyzer, and the results are shown in Table 5:

[0160] Other conditions were the same as in Test Example 1, and only the type of catalyst was changed to carry out the reactions of Test Examples 2-7 and Comparative Test Examples 1-5.

[0161]

[0162] It can be seen from the data in Table 5 that the waste residue produced by using the pretreated catalytic reforming catalyst, the binder prepared by a specific method, and the modified alumina prepared to obtain a catalytic cracking aid can work synergistically to reduce CO in the catalytic cracking regeneration flue gas while controlling NO x emissions and achieve the green resource utilization of the precious metal-containing waste residue in the catalyst plant.

[0163] By analyzing the data of Examples 1 and 3, it can be seen that adding aluminum sol during the preparation process of the pseudo-boehmite binder can reduce the concentrations of CO and NO in the catalytic cracking flue gas x .

[0164] By analyzing the data of Comparative Example 1, it can be seen that using the waste residue produced by the catalytic reforming catalyst containing precious metals in this application as the raw material for preparing the catalytic cracking aid is beneficial to reducing the concentrations of CO and NO in the catalytic cracking flue gas x .

[0165] By analyzing the data of Comparative Example 2, it can be seen that the modified alumina prepared by the specific method of this application can work synergistically with the waste residue and the binder, which is beneficial to reducing the concentrations of CO and NO in the catalytic cracking flue gas x .

[0166] By analyzing the data of Comparative Examples 3-4, it can be seen that the alumina prepared by the specific method of this application has more excellent performance in reducing CO and NO in the catalytic cracking flue gas compared with the conventional alumina of the prior artx Performance of concentration.

[0167] By analyzing the data of Comparative Example 5, it can be seen that the binder prepared by the specific method of the present application can cooperate with the waste residue and modified alumina to play a role synergistically compared with the conventional binder in the prior art, which is beneficial to the reduction of the concentrations of CO and NO in the catalytic cracking flue gas. x Reduction of concentration.

[0168] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0169] In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not describe various possible combination methods separately.

Claims

1. A preparation method of a catalytic cracking promoter, characterized in that The method comprises the following steps: (1) Pulping the spent catalyst residue of catalytic reforming containing precious metals to obtain a slurry; preferably, the solid content of the slurry is 5wt% - 15wt%; (2) Subjecting the slurry to fine grinding treatment and controlling the particle size to D(V,0.5) ≤ 1μm and D(V,0.9) ≤ 3μm to obtain the ground slurry; (3) Mixing and pulping the ground slurry, modified alumina, and binder to obtain a mixed slurry, followed by spray drying; The composition of the modified alumina includes: the alumina content is 50wt% - 95wt%, and the active metal content is 5wt% - 50wt%; the active metal is selected from one or more of Fe, Co, Mn, Mg, Cu, and Zr; preferably one or more of Fe, Co, Mn, and Mg.

2. The method according to claim 1, characterized in that The precious metal is selected from one or two of Pt and Pd.

3. The method according to claim 1, characterized in that, In the waste residue, based on the dry weight, the Al2O3 content is 90wt% - 99wt%, the precious metal content is 0.01wt% - 0.5wt%, and the SiO2 content is 0.01wt% - 10wt%.

4. The method according to claim 1, characterized in that The pore volume of the modified alumina is 0.4 mL / g to 1.0 mL / g, and the specific surface area is 100 m 2 / g to 300 m 2 / g.

5. The method according to claim 1, wherein The composition of the modified alumina further includes: the sodium oxide content is 0.01wt% - 1.0wt%, and the silicon dioxide content is 0.01wt - 3wt%.

6. The method according to claim 1, characterized in that, The preparation method of the modified alumina includes: S1. Calcining aluminum hydroxide at a calcination temperature of 500°C - 800°C; S2. Pulping the calcined aluminum hydroxide to obtain an aluminum hydroxide slurry, and controlling the solid content of the aluminum hydroxide slurry to 10wt% - 30wt%; S3. Adding hydrochloric acid, adjusting the pH to 4 - 6, filtering, drying, and calcining to obtain alumina; S4. Supersaturating and impregnating the alumina obtained in step S3 with the mixed salt solution of the active metal, drying, and calcining to obtain the modified alumina.

7. The method according to claim 6, wherein In step S3, the drying temperature is 100°C - 300°C; the calcination temperature is 450°C - 650°C, and the calcination time is 1h - 3h.

8. The method according to claim 6, characterized in that In step S4, the drying temperature is 100°C - 300°C; the calcination temperature is 500°C - 800°C, and the time is 1h - 3h.

9. The method according to claim 6, wherein In step S4, the salt of the active metal is one or more of nitrate, hydrochloride, and organic salt.

10. The method according to claim 1, wherein In step (3), the binder is pseudoboehmite, or a composition of pseudoboehmite and aluminosol.

11. The method according to claim 1, wherein In step (3), the preparation method of the binder includes: S01. Pulping pseudoboehmite with water and controlling the solid content of the slurry to 5wt% - 10wt%; S02. Adding acid to adjust the pH to 1 - 2.5; S03. Aging at a temperature of 50°C - 90°C for 1h - 5h; S04. Adding ammonia water to adjust the pH to 3.5 - 5.

5.

12. The method according to claim 11, wherein In step S02, the acid is one or more of organic acid and inorganic acid; among them, the organic acid is one or more of formic acid, acetic acid, and oxalic acid, and the inorganic acid is one or more of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

13. The method according to claim 11, wherein In the step S03, it further includes adding aluminum sol before the aging treatment.

14. The method according to claim 1, wherein In the step (3), the temperature of the spray drying is 180°C to 250°C.

15. A catalytic cracking promoter, characterized in that, The auxiliary agent is prepared by the method described in any one of claims 1-14.

16. The auxiliary agent according to claim 15, wherein The composition of the auxiliary agent is: the content of the waste residue is 5wt% to 30wt%, the content of the modified alumina is 10wt% to 50wt%, and the content of the binder is 40wt% to 70wt%.

17. Use of the auxiliary agent according to claim 15 or 16 in reducing the CO concentration in the flue gas from catalytic cracking regeneration while controlling NO X emissions.

Images