CN101837299A - Catalyst for catalytic gasoline hydrogenation modification and preparation method thereof - Google Patents

Abstract

A catalyst for hydrogenation modification of catalytic gasoline, a preparation method and application thereof. Firstly, placing an HZSM-5 molecular sieve or a hydrothermally treated HZSM-5 molecular sieve in an aqueous alkali according to a liquid-solid ratio of 5ml/g to 15ml/g, adjusting the pH to 9 to 14, treating for 2 to 6 hours at 60 to 90 ℃, washing, drying, performing ammonium exchange, drying, roasting, and performing hydrothermal treatment at 400 to 600 ℃ to obtain a modified HZSM-5 molecular sieve; extruding the modified HZSM-5 molecular sieve and a binder into strips, drying and roasting to prepare a catalyst carrier; and loading a metal active component on the catalyst carrier, and drying and roasting to obtain the target catalyst. The modified HZSM-5 molecular sieve catalyst provided by the invention has higher activity and stability in the hydro-upgrading of the catalytic gasoline.

Description

Catalyst for hydro-upgrading of catalytic cracking gasoline and preparation method thereof

technical field

The invention relates to a catalyst for hydrogenation upgrading of catalytic cracking gasoline and a preparation method thereof.

Background technique

In order to control the air pollution caused by vehicle exhaust emissions, countries around the world have formulated clean gasoline standards marked by low sulfur and low olefin content. Judging from the existing technological process and development trend of my country's petroleum processing industry, for a long period of time in the future, the blending components of my country's motor gasoline are mainly catalytic cracked gasoline, and high-octane components (reformed gasoline and alkylated gasoline) is difficult to fundamentally change the status quo. Therefore, in order to meet the increasingly stringent requirements of clean gasoline standards, the upgrading of FCC gasoline has become one of the key technologies for the production of clean fuel for vehicles in my country. Difficulties in the subject of desulfurization and reduction of olefin content.

USP 5,362,376 introduces a two-stage catalyst combination process for gasoline hydrodesulfurization and octane recovery. The heavy fraction of FCC gasoline is first desulfurized by a conventional hydrodesulfurization catalyst Ni-Mo/Al ₂ O ₃ or Co-Mo/Al ₂ O ₃ , and then the desulfurized product is treated by a NiO/HZSM-5 molecular sieve catalyst. Shape-selective cracking or isomerization of low-octane paraffins to high-octane paraffins, thereby recovering the octane loss caused by olefin saturation in the first-stage hydrodesulfurization process, and then combined with pre-fractionated FCC gasoline The light fractions are blended together. The patent pointed out that too weak acidity of molecular sieves reduces the cracking activity of the catalyst and affects the recovery effect of octane number; while too strong acidity of molecular sieves will lead to excessive cracking reactions and affect the liquid yield of final gasoline products; ideal molecular sieve acidity should be guaranteed Moderate cracking and molecular rearrangement and other reactions such as recovery of octane number occur.

USP 5,413,698 introduces another hydrodesulfurization/octane recovery two-stage combined catalytic gasoline desulfurization process. The heavy fraction of catalytic gasoline is firstly desulfurized by a conventional hydrodesulfurization Mo-Co or Mo-Ni catalyst, and then the desulfurized product is selectively cracked by medium-pore HZSM-5 molecular sieve/large-pore HBeta molecular sieve catalyst containing nickel oxide, and the low Crack high-octane macromolecular alkanes into high-octane small-molecular alkanes, and isomerize low-octane n-paraffins into high-octane multi-branched isoparaffins, thereby restoring the hydrodesulfurization process Octane loss due to hydrosaturation of medium olefins.

Since the olefin content (40-55v%) of my country's FCC gasoline is much higher than that of foreign countries (20-30v%), it is difficult to obtain the existing FCC gasoline hydrogenation upgrading technology applied to my country's FCC gasoline hydrogenation reaction. Satisfying result.

CN93102129.4 discloses a catalytic reforming-aromatization method for inferior gasoline. Crude catalytically cracked gasoline is first catalytically upgraded under non-hydrogen-facing conditions, and then aromatized on Zn-Al or Zn-Al-rare earth HZSM-5. The aromatization temperature is 480-650 °C and the pressure is 0.05 ~1.5MPa. The final gasoline yield is 55-75wt%. Because the carbon deposition of the aromatization catalyst deactivates quickly, the aromatization catalyst generally needs to be regenerated once every 15 days.

CN99108827.1, CN200410028083.1 etc. disclose the catalyst that takes HZSM-5 molecular sieve as carrier Mo and CN200410024877.0, CN02135601.7, CN02115329.9, CN200610035278.8 etc. disclose that HZSM-5 molecular sieve is carrier Mo and Fe, Cu and other active components are used as catalysts.

CN00122963.X discloses a low carbon hydrocarbon aromatization catalyst, with HZSM-5 molecular sieve and alumina as carrier, nickel and zinc as active components; CN85100324 discloses a kind of HZSM-5 molecular sieve as substrate, clay or aluminum oxide as a binding agent, with nickel as the hydrogen depreciation catalyst of the active component; CN200410080227.8 discloses a method for producing diesel oil by lamination of carbon tetraolefins, and its lamination catalyst includes 1～20wt% NiO, 40-80 wt% of HZSM-5 molecular sieve and 1-50 wt% of alumina. The usual preparation method of this type of catalyst is to knead HZSM-5, alumina powder, and inorganic acid to form, dry, and roast, and some of them are further hydrothermally treated, and then dried, roasted, or hydrothermally treated after impregnating active components. CN96108703.X discloses a catalyst for directly synthesizing aromatics from methane, which is characterized in that MoO ₃ is used as the first modified substance, and one of ZnO, WO ₃ , CuO, Cr ₂ O ₃ , and NiO is used as the second modified substance , modified HZSM-5 zeolite, the component Mo ⁶⁺ content is 3-6%, the molar ratio of the second component to the first component M ⁿ⁺ /Mo ⁶⁺ is 0.01-0.11, and the balance is HZSM-5. The catalyst is prepared by an impregnation method or a solid-state grinding method, and the preparation process is simple. Compared with a single-component catalyst, the conversion rate of methane is improved, and the catalyst does not contain alumina components.

Contents of the invention

The purpose of the present invention is to provide a catalyst with high activity and high stability which is applied to the hydrogenation upgrading of catalytic cracking gasoline.

In order to achieve the above object, the catalytic cracking gasoline hydro-upgrading catalyst provided by the present invention is characterized in that: in terms of catalyst weight, the catalyst contains 20-80wt% modified HZSM-5 molecular sieve, 10-80wt% binding agent, 3-10wt% molybdenum oxide, 1-5wt% nickel oxide; the modified HZSM-5 molecular sieve is obtained by the following method: HZSM-5 molecular sieve is subjected to alkali treatment, ammonium exchange and hydrothermal treatment to make modified HZSM-5 5 molecular sieve; alkali treatment is to put HZSM-5 molecular sieve or HZSM-5 molecular sieve after hydrothermal treatment in the alkali solution at a liquid-solid ratio of 5-15ml/g, adjust the pH to 9-14, and stir at 60-90°C After 2-6 hours, the product is filtered, washed, dried at 110-130°C, and calcined at 450-520°C for 2-6 hours. The base used is selected from NaOH, KOH, Na ₂ CO ₃ or K ₂ CO ₃ , preferably NaOH.

In the present invention, the conditions of hydrothermal treatment and ammonium exchange are the same as those of the prior art, and the present invention has no special requirements.

The ammonium exchange described in the present invention is preferably placed in the ammonium solution through the alkali-treated HZSM-5 molecular sieve, wherein molecular sieve: ammonium salt: water weight ratio is 1: 0.2～1.8: 5～15, and at 60～ Stir at 98°C for 2-6 hours, then filter and wash the product, dry at 110-130°C, and roast at 450-520°C for 2-6 hours. The ammonium used is selected from NH ₄ NO ₃ or NH ₄ Cl, preferably NH ₄ NO ₃ .

The hydrothermal treatment described in the present invention is preferably HZSM-5 molecular sieve or the HZSM-5 molecular sieve that has been treated with alkali and exchanged with ammonium at 400-600 °C for 2-6 hours; 25-80.

The binder in the present invention refers to one or more of pseudo-boehmite, Al ₂ O ₃ , SiO ₂ , and diatomaceous earth.

In the prior art, catalysts are obtained more by directly mixing HZSM-5 molecular sieves with binders, adding _HNO3 aqueous solution, kneading, extruding, drying and roasting to make catalyst supports; The method of loading metal active components on the top, drying and roasting to make a catalyst, the difference of the present invention is that the modified HZSM-5 molecular sieve is used instead of the ordinary HZSM-5 molecular sieve, and the rest can be used. Common operating conditions in technology.

In the present invention, alkali treatment and ammonium exchange are very necessary when HZSM-5 molecular sieve is modified. If only hydrothermal treatment can only adjust the acidity of molecular sieve but cannot optimize the pore structure of molecular sieve; if only alkali treatment does not For ammonium exchange, the molecular sieve is Na type, with weak acidity; if there is only alkali treatment and ammonium exchange without hydrothermal treatment, the pore structure of the molecular sieve can only be adjusted but the acidity of the molecular sieve cannot be optimized. Alkali treatment and ammonium exchange can be carried out before or after hydrothermal treatment, preferably before hydrothermal treatment, so that the acidity and pore structure of the molecular sieve can be optimized more effectively, thereby improving the reaction of the corresponding catalyst performance.

Since the modified HZSM-5 molecular sieve is obtained by subjecting the HZSM-5 molecular sieve to alkali treatment and ammonium exchange before hydrothermal treatment or hydrothermal treatment first and then alkali treatment and ammonium exchange, it has comprehensively optimized acidity and hole structure.

The present invention also provides an optimal preparation method of the catalyst, comprising mixing the modified HZSM-5 molecular sieve with a binder, kneading, molding, drying, and roasting at 480-650°C for 3-7 hours to prepare the catalyst Carrier: molybdenum oxide and nickel oxide are supported by impregnation, dried and calcined at 450-520°C for 3-5 hours to make a catalyst.

In the present invention, it is better to add 2-6wt% squid powder and 3-10wt% _HNO3 aqueous solution in the process of carrier kneading and molding, which is beneficial to the extrusion of the carrier and has higher mechanical strength.

In the present invention, when loading the metal active component, it is best to use the aqueous solution of the precursor of the metal active component, that is, the ratio of the pore volume of the impregnation solution to the carrier is 0.8 to 1.2, and then adopt step-by-step impregnation and step-by-step roasting activation, or step by step Immersion once roasting activation, the present invention is not particularly required.

The best preparation method recommended by the present invention is: when the metal active component is loaded, molybdenum is first loaded and then nickel is loaded, followed by step-by-step roasting, which can be specifically:

Immerse the catalyst carrier in the ammonium molybdate solution for 6-12 hours, dry, and roast at 450-520°C for 2-6 hours to obtain a catalyst intermediate containing molybdenum oxide; immerse the catalyst intermediate in the nickel nitrate solution, The catalyst is obtained after drying and calcining at 450-520°C for 2-6 hours.

The catalyst provided by the invention can be used in the hydrogenation and upgrading of catalytic cracking gasoline, and has the ability of hydrodesulfurization, isomerization/aromatization and olefin reduction. Compared with the unmodified catalyst, the catalyst of the invention shows higher reaction stability.

Detailed ways

Raw material sources and analysis method standards:

HZSM-5 molecular sieve (SiO ₂ /Al ₂ O ₃ molar ratio = 51.2): Shanghai Huaheng Chemical Factory;

Pseudo-boehmite (containing 76wt% Al ₂ O ₃ and 24wt% water of crystallization): German Sasol company;

Diatomite: Tianjin Yuanli Chemical Co., Ltd.;

Alumina: γ-Al ₂ O ₃ ;

SiO ₂ : Tianjin Yuanli Chemical Co., Ltd.;

Tianjing powder: Fushun Petrochemical Research Institute of China Petroleum & Chemical Corporation;

Research octane number (RON): GB/T5487;

Liquid yield: liquid product mass/feed mass × 100%;

Catalyst active component content determination method: X-ray fluorescence;

SiO ₂ /Al ₂ O ₃ molar ratio measurement method: X-ray fluorescence.

The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

Catalyst evaluation was carried out on an isothermal fixed bed, and the composition of FCC whole gasoline used was as follows (v%): normal paraffins: 5.94; isoparaffins: 31.76; olefins: 35.66; naphthenes: 7.42; aromatics: 19.22. The sulfur content of this catalytically cracked full distillate gasoline was 76 μg/g, and the RON was 91.6.

Example 1

Put the HZSM-5 molecular sieve in the aqueous NaOH solution at a liquid-solid ratio of 10ml/g, adjust the pH to 13, and stir at 75°C for 4 hours. Filter, wash until neutral, dry at 120°C for 3 hours, and roast at 480°C for 4 hours; HZSM-5 molecular sieve treated with NaOH is stirred at 80°C for 4 hours at a molecular sieve: ammonium salt: water weight ratio of 1:0.8:10, Then the product was filtered, washed, dried at 120°C, and calcined at 480°C for 4 hours; the obtained HZSM-5 molecular sieve was broken into 20-40 mesh particles, put into a hydrothermal treatment furnace, heated at 520°C, 100% water The synthetically modified HZSM-5 molecular sieve was obtained after being treated in steam for 4 hours.

Take by weighing 50 grams of comprehensively modified HZSM-5 molecular sieves, 26 grams of pseudo-boehmite binder and 2.4 grams of squash powder, and grind and mix them uniformly, add 33ml of nitric acid solution with a concentration of 4.6 grams/100ml, fully After kneading, extrude into strips with a diameter of 1.5 mm on an extruder. After being dried at 120°C, it was calcined at 520°C for 6 hours, and cut into strips of 2-3mm to make catalyst carriers.

30 grams of the above-mentioned catalyst carrier was impregnated in 22 ml of ammonium molybdate solution containing 2.1 grams of MoO ₃ , left at room temperature for 9 hours, dried at 120°C for 3 hours, and calcined at 480°C for 4 hours to prepare a catalyst intermediate.

Catalyst 1 was prepared by immersing the above catalyst intermediate in 22ml of nickel nitrate solution containing 0.9g of NiO, standing at room temperature for 9 hours, drying at 120°C for 3 hours, and calcining at 480°C for 4 hours. Among them, molecular sieve 64.85%, MoO ₃ 6.36%, NiO 2.73%.

Example 2

The preparation method is the same as that of Example 1, except that 20 grams of Al ₂ O ₃ is used as the binder during the preparation of the carrier. Catalyst 2 was finally obtained. Among them, molecular sieve 64.94%, MoO ₃ 6.36%, NiO 2.73%.

Example 3

The preparation method is the same as that of Example 1, except that the binder is 15 grams of Al ₂ O ₃ and 4 grams of SiO ₂ during the preparation of the carrier. Catalyst 3 was finally obtained. Among them, molecular sieve 65.87%, MoO ₃ 6.36%, NiO 2.73%.

Example 4

The preparation method is the same as that of Example 1, except that the binder is 15 grams of γ-A1 ₂ O ₃ and 4.5 grams of diatomaceous earth during the preparation of the carrier. Catalyst 4 was finally obtained. Among them, molecular sieve 65.82%, MoO ₃ 6.36%, NiO 2.73%.

Example 5

The preparation method is the same as that of Example 1, except that the binder is 15 grams of pseudo-boehmite and 9.2 grams of Al ₂ O ₃ during the preparation of the carrier. Catalyst 5 was finally obtained. Among them, molecular sieve 64.38%, MoO ₃ 6.36%, NiO 2.73%.

Example 6

The preparation method is the same as in Example 1, except that the HZSM-5 molecular sieve is subjected to hydrothermal treatment first, and then NaOH treatment and NH ₄ NO ₃ ion exchange. Catalyst 6 was finally obtained. Among them, molecular sieve 64.85%, MoO ₃ 6.36%, NiO 2.73%.

Example 7

The preparation method is the same as that of Example 6, except that the binder in the carrier preparation process is 15 grams of Al ₂ O ₃ , 2.0 grams of diatomaceous earth and 3.5 grams of SiO ₂ . Catalyst 7 was finally obtained. Among them, molecular sieve 64.65%, MoO ₃ 6.36%, NiO 2.73%.

Example 8

The preparation method is the same as that of Example 6, except that the binder in the carrier preparation process is 15 grams of pseudoboehmite, 5 grams of Al ₂ O ₃ , 2.0 grams of diatomaceous earth and 3.5 grams of SiO ₂ . Catalyst 8 was finally obtained. Among them, molecular sieve 63.39%, MoO ₃ 6.36%, NiO 2.73%.

Example 9

The preparation method is the same as that in Example 1, except that the HZSM-5 molecular sieve is subjected to hydrothermal treatment + NaOH treatment + NH ₄ NO ₃ ion exchange, and then 50 grams of modified HZSM-5 molecular sieve and 43.8 grams of pseudoboehmite are weighed. stone and 3.3 grams of squat powder, and it is ground and mixed evenly, and the nitric acid solution that the concentration of 46ml is added is 4.6 grams/100ml, after fully kneading, extrude on the extruder and be the bar that diameter is 1.5mm. After being dried at 120°C, it is calcined at 480°C for 6 hours, and cut into strips of 2-3 mm to make catalyst supports.

30 grams of the above-mentioned catalyst carrier was impregnated in 20 ml of ammonium molybdate solution containing 0.9 g of MoO ₃ , left at room temperature for 9 hours, dried at 120°C for 3 hours, and calcined at 500°C for 4 hours to prepare a catalyst intermediate.

The above catalyst intermediate was immersed in 20ml of nickel nitrate solution containing 0.3g of NiO, left to stand at room temperature for 9 hours, dried at 120°C for 3 hours, and calcined at 500°C for 4 hours to finally obtain catalyst 9. Among them, molecular sieve is 57.72%, MoO ₃ is 2.88%, and NiO is 0.96%.

Example 10

The preparation method is the same as that of Example 9, except that the binder in the carrier preparation process is 25 grams of Al ₂ O ₃ and 5 grams of diatomaceous earth. Catalyst 10 was finally obtained. Among them, molecular sieve 60.47%, MoO ₃ 2.88%, NiO 0.96%.

Example 11

The preparation method is the same as that of Example 9, except that the binder in the carrier preparation process is 15 grams of pseudo-boehmite, 15 grams of Al ₂ O ₃ , and 5 grams of diatomaceous earth. Catalyst 11 was finally obtained. Among them, molecular sieve is 59.42%, MoO ₃ is 2.88%, and NiO is 0.96%.

Example 12

Put the HZSM-5 molecular sieve in the aqueous NaOH solution at a liquid-solid ratio of 15ml/g, adjust the pH to 9, and stir at 90°C for 2 hours. Filter, wash until neutral, dry at 120°C for 3 hours, and roast at 480°C for 4 hours; HZSM-5 molecular sieve treated with NaOH is stirred at 98°C for 2 hours at a weight ratio of molecular sieve:ammonium salt:water of 1:0.2:15, Then the product was filtered, washed, dried at 120°C, and calcined at 480°C for 4 hours; the obtained HZSM-5 molecular sieve was broken into 20-40 mesh particles, put into a hydrothermal treatment furnace, and passed through 100°C at 400°C After being treated with % water vapor for 6 hours, the synthetically modified HZSM-5 molecular sieve was obtained after drying and grinding.

Weigh 30 grams of comprehensively modified HZSM-5 molecular sieves, 35 grams of Al ₂ O ₃ and 4.00 grams of scallop powder, grind and mix them evenly, add 15 ml of nitric acid solution with a concentration of 5.6 grams/100 ml, fully knead and squeeze Extrude into strips with a diameter of 1.5 mm on a strip machine. After being dried at 120°C, it is calcined at 500°C for 6 hours, cut into strips of 2-3mm, and made into a catalyst carrier.

20 grams of the above-mentioned catalyst carrier was impregnated in 16 ml of ammonium molybdate solution containing 2.5 grams of MoO ₃ , left to stand at room temperature for 9 hours, dried at 120°C for 3 hours, and calcined at 480°C for 4 hours to prepare a catalyst intermediate.

The above catalyst intermediate was immersed in 16ml of nickel nitrate solution containing 1.5g of NiO, left to stand at room temperature for 9 hours, dried at 120°C for 3 hours, and calcined at 480°C for 4 hours to finally obtain catalyst 12. Among them, molecular sieve is 38.46%, MoO ₃ is 10.41%, and NiO is 6.25%.

Example 13

The preparation method was the same as that of Example 12, except that the binder was 20.0 g of pseudoboehmite, 10 g of Al ₂ O ₃ and 5.0 g of diatomaceous earth during the preparation of the carrier, and finally Catalyst 13 was obtained. Among them, molecular sieve is 41.87%, MoO ₃ is 10.41%, and NiO is 6.25%.

Example 14

The preparation method was the same as in Example 9, except that HZSM-5 molecular sieves were placed in NaOH aqueous solution at a liquid-solid ratio of 5ml/g, the pH was adjusted to 11, and stirred at 60°C for 6 hours. Filter and wash until neutral, dry at 120°C for 3 hours, and roast at 500°C for 4 hours, then stir at 60°C for 6 hours according to molecular sieve:ammonium salt:water weight ratio of 1:1.8:5, then filter and wash the product, And dry at 120°C and roast at 500°C for 4 hours; break the obtained HZSM-5 molecular sieve into 20-40 mesh particles, put them in a hydrothermal treatment furnace, and pass 100% steam at 600°C for 2 hours, and then dry Finally, a comprehensively modified HZSM-5 molecular sieve was obtained.

Weigh 50 grams of comprehensively modified HZSM-5 molecular sieves, 10 grams of Al ₂ O ₃ and 2.4 grams of scallop powder, and grind and mix them evenly, add 30 ml of nitric acid solution with a concentration of 4.6 grams/100 ml, fully knead and squeeze Extrude into strips with a diameter of 1.5 mm on a strip machine. After being dried at 120°C, it was calcined at 520°C for 6 hours, and cut into strips of 2-3mm to make catalyst carriers. All the other preparation methods are the same as in Example 9. Catalyst 14 was finally obtained. Among them, molecular sieve is 80.12%, MoO ₃ is 2.88%, and NiO is 0.96%.

Example 15

Put the HZSM-5 molecular sieve in the NaOH solution at a liquid-solid ratio of 10ml/g, adjust the pH to 14, and stir at 80°C for 3 hours. Filter and wash until neutral, dry at 120°C for 3 hours, and roast at 450°C for 4 hours, then stir at 70°C for 6 hours according to molecular sieve:ammonium salt:water weight ratio of 1:1:10, then filter and wash the product, It was dried at 120°C and calcined at 480°C for 4 hours; the obtained HZSM-5 molecular sieve was broken into 20-40 mesh particles, put into a hydrothermal treatment furnace, and treated in water vapor at 550°C for 2 hours, and dried to obtain Comprehensively modified HZSM-5 molecular sieve.

Take by weighing 10 grams of comprehensively modified HZSM-5 molecular sieves, 50 grams of pseudo-boehmite and 5 grams of scallop powder, and grind and mix them uniformly, add 45ml of nitric acid solution with a concentration of 4.6 grams/100ml, fully knead and squeeze Extrude into strips with a diameter of 1.5 mm on a strip machine. After being dried at 120°C, it was calcined at 520°C for 6 hours, and cut into strips of 2-3mm to make catalyst carriers. All the other preparation methods are the same as in Example 1. Catalyst 15 was finally obtained. Among them, molecular sieve is 18.93%, MoO ₃ is 6.36%, and NiO is 2.73%.

Example 16

The preparation method was the same as that of Example 15, except that the binder was 20.0 g of pseudoboehmite, 15 g of Al ₂ O ₃ and 5.0 g of diatomaceous earth during the preparation of the carrier, and finally Catalyst 16 was obtained. Among them molecular sieve 20.33%, MoO ₃ 6.36%, NiO 2.73%.

Comparative example 1

The preparation method is the same as that of Example 9, except that the HZSM-5 molecular sieve is not subjected to any treatment. Catalyst 17 was finally obtained. Among them, molecular sieve is 57.72%, MoO ₃ is 2.88%, and NiO is 0.96%.

Comparative example 2

The preparation method is the same as in Example 1, except that the HZSM-5 molecular sieve is only subjected to hydrothermal treatment. Catalyst 18 was finally obtained. Among them, molecular sieve 64.85%, MoO ₃ 6.36%, NiO 2.73%.

Comparative example 3

The preparation method is the same as that of Example 1, except that only NaOH treatment and NH ₄ NO ₃ ion exchange are performed on the HZSM-5 molecular sieve. Catalyst 19 was finally obtained. Among them, molecular sieve 64.85%, MoO ₃ 6.36%, NiO 2.73%.

Example 17

This example illustrates the application of the catalyst prepared by the present invention and the catalyst of the comparative example in the hydrogenation upgrading of FCC gasoline.

Catalysts 1-19 were respectively charged into a continuous fixed-bed reactor, and the catalyst loading amount was 4 grams (about 6 ml). Firstly, the catalyst is presulfurized by purging with N ₂ for 1 h. The sulfidation liquid is straight-run gasoline containing 3wt% CS ₂ , the sulfidation pressure is 2.8 MPa, the volume ratio of hydrogen to oil is 300, and the weight hourly space velocity is 2.0 h ^-1 . hour, 230°C, 260°C, 290°C and 320°C for 4 hours respectively. The catalyst evaluation conditions are temperature 390°C, pressure 1.8MPa, hydrogen-to-oil volume ratio 200, and weight hourly space velocity 2.0h ^-1 . The evaluation results are shown in Table 1.

It can be seen from Table 1 that catalysts 1 to 19 all have good hydrodesulfurization capabilities, but their hydroisomerization and aromatization activities are different, indicating that the modification method, modification conditions, and composition of the catalyst carrier of the molecular sieve and metal loading affect the reactivity of the catalyst.

By comparing the reaction performance of catalysts 1-8 and 17-19, it can be seen that the modification method of HZSM-5 molecular sieve affects the reaction performance of the catalyst. After 72 hours of reaction, the catalyst prepared by HZSM-5 molecular sieve without any modification treatment and only NaOH+NH ₃ NO ₄ ion exchange treatment has a certain degree of hydroisomerization activity, but the aromatization activity is very low . This is mainly because the acidity of catalysts 17 and 18 is stronger, which makes the deactivation of catalyst carbon deposition faster. Hydrothermal treatment of HZSM-5 molecular sieve can reduce the acidity of the catalyst, and the prepared catalyst 19 still has good olefin hydroisomerization activity after 72 hours of reaction, but the aromatization activity is low. By comparing the reaction performance of catalysts 1 to 8, it can be seen that compared with hydrothermal treatment followed by alkali treatment, hydrothermal treatment after alkali treatment can more effectively adjust the acidity of molecular sieves, form more mesopores, and reduce the catalyst deactivation rate. reduce.

By comparing the reaction performance of catalysts 1 to 16, it can be seen that the modification conditions of HZSM-5 molecular sieve, the composition of the catalyst support and the metal loading affect the reaction performance of the catalyst. The higher metal loading on the catalyst can improve the desulfurization activity of the catalyst, and the aromatization shape selectivity and octane number retention ability of the catalyst can be improved when the catalyst carrier contains more HZSM-5 molecular sieve. After 72 hours of reaction, catalyst 1 still had high hydrodesulfurization, hydroisomerization and aromatization activities, showing the best comprehensive reaction performance.

Table 1 Results of FCC gasoline hydro-upgrading reaction on catalyst (72h)

From the above analysis, it can be seen that Catalyst 1 has a better effect in hydro-upgrading of FCC gasoline. Therefore, Catalyst 1 was selected for the stability study of FCC gasoline hydro-upgrading. The results are shown in Table 2. It can be seen that the catalyst has high olefin reduction ability, good activity and stability of hydroisomerization and aromatization, the octane number of product research method is basically equivalent to that of feedstock oil, and has high liquid yield. It shows a certain industrial application prospect.

The stability experiment result of table 2 catalyst 1

Claims (12)

1. A catalytic cracking gasoline hydrogenation upgrading catalyst is characterized in that: by catalyst weight, the HZSM-5 molecular sieve containing 20～80wt% modification in the catalyst, 10～80wt% binding agent, 3～10wt% oxidation Molybdenum, 1-5wt% nickel oxide; wherein the modified HZSM-5 molecular sieve is obtained by the following method: the HZSM-5 molecular sieve is subjected to alkali treatment, ammonium exchange and hydrothermal treatment to make a modified HZSM-5 molecular sieve; alkali treatment It is to put HZSM-5 molecular sieve or HZSM-5 molecular sieve after hydrothermal treatment in the alkali solution at a liquid-solid ratio of 5-15ml/g, adjust the pH to 9-14, and stir at 60-90°C for 2-6 hours. Then the product is filtered, washed, dried at 110-130°C, and calcined at 450-520°C for 2-6 hours. 2. The catalyst according to claim 1, characterized in that the base is selected from NaOH, KOH, Na ₂ CO ₃ or K ₂ CO ₃ . 3. Catalyst according to claim 1, it is characterized in that: ammonium exchange is that the HZSM-5 molecular sieve through alkali treatment is placed in ammonium solution, wherein molecular sieve: ammonium salt: water weight ratio is 1: 0.2～1.8: 5 ～15, and stirred at 60～98°C for 2～6 hours, then the product was filtered, washed, dried at 110～130°C, and calcined at 450～520°C for 2～6 hours. 4. The catalyst _according to claim 3, characterized in that the ammonium is selected from _NH4NO3 or _NH4Cl . 5. The catalyst according to claim 1, characterized in that: the hydrothermal treatment is to pass HZSM-5 molecular sieve or HZSM-5 molecular sieve after alkali treatment and ammonium exchange into steam at 400-600°C for 2-6 hours. 6. The catalyst according to claim 1, characterized in that: the ratio of silicon to aluminum of HZSM-5 molecular sieve is 25-80. 7 . The catalyst according to claim 1 , wherein the binder refers to one or more of pseudo-boehmite, Al ₂ O ₃ , SiO ₂ , and diatomaceous earth. 8. A method for preparing the catalyst as claimed in claim 1, characterized in that the modified HZSM-5 molecular sieve is mixed with the binder, after kneading, extruding, drying, and roasting at 480-650°C for 3-7 hours, The catalyst carrier is prepared; molybdenum oxide and nickel oxide are supported by impregnation, dried and calcined at 450-520° C. for 3-5 hours to prepare the catalyst. 9. The preparation method of the catalyst according to claim 8, characterized in that: 2-6wt% turmeric powder and 3-10wt% _HNO3 aqueous solution are added in the process of carrier kneading and extruding. 10. The preparation method of the catalyst according to claim 8, characterized in that: when molybdenum oxide and nickel oxide are supported by impregnation, the ratio of the pore volume of the impregnating solution to the carrier is 0.8 to 1.2 to prepare molybdenum oxide and nickel oxide. An aqueous precursor solution of nickel metal was used as the impregnating solution. 11. The preparation method of the catalyst according to claim 8, characterized in that: when the molybdenum oxide and nickel oxide are loaded by impregnation, the molybdenum is first loaded and then the nickel is loaded, followed by step-by-step roasting. 12. The preparation method of the catalyst according to claim 8, characterized in that: the catalyst carrier is immersed in the ammonium molybdate solution for 6-12 hours, dried and calcined at 450-520°C for 2-6 hours to obtain molybdenum oxide-containing The catalyst intermediate; the catalyst intermediate is soaked in nickel nitrate solution, dried and calcined at 450-520° C. for 2-6 hours to obtain the catalyst.