A continuous reforming catalyst and its preparation method and application

Abstract

The present invention provides a continuous reforming catalyst, a preparation method, and an application thereof. The preparation method of the continuous reforming catalyst comprises: preparing a Sn-containing alumina carrier molding; calcining the molding in an oxygen-free atmosphere to obtain an alumina carrier; impregnating the alumina carrier with an impregnation liquid, wherein the impregnation liquid comprises a Pt-containing compound, a K-containing compound, and a competitive adsorbent to obtain an impregnated alumina carrier; and drying, activating, and reducing the impregnated alumina carrier to obtain a continuous reforming catalyst. The continuous reforming catalyst of the present invention is prepared by the preparation method. The present invention also provides the application of the continuous reforming catalyst in the continuous reforming of naphtha to produce high-octane gasoline blending components or aromatics. The platinum atoms in the continuous reforming catalyst of the present invention have a strong interaction with the carrier, which can meet the high-rigidity reaction process requirements of catalytic reforming.

Description

Technical Field

[0001] The present invention relates to a continuous reforming catalyst and a preparation method and application thereof, in particular to a Pt-Sn-K continuous reforming catalyst and a preparation method and application thereof, belonging to the technical field of reforming catalysts. Background Art

[0002] Catalytic reforming is a key process in petroleum processing, primarily producing high-octane gasoline, BTX aromatics, and inexpensive hydrogen. With the integration of refining and petrochemicals, catalytic reforming is becoming increasingly important within the refining and petrochemical industry. Currently, the most commonly used reforming catalysts in industry are Pt-Re / Al2O3 for semi-regenerative reforming and Pt-Sn / Al2O3 for continuous regenerative reforming.

[0003] CN101898131A discloses a dehydrogenation catalyst and its preparation method. The catalyst has an alkali metal content of 0.1-5% by mass, and after being dechlorinated by steam, the catalyst contains virtually no chlorine. The catalyst can be used for propane dehydrogenation.

[0004] CN102049267A discloses a propane dehydrogenation catalyst, its preparation method, and application. The catalyst contains 0.1-2.0% by mass of a platinum group metal, 0.1-2.0% by mass of a Group IVA metal, 0.5-5.0% by mass of potassium, 0.2-5.0% by mass of cerium or samarium, and 0.3-10.0% by mass of a halogen.

[0005] US20130256194A1 discloses a reforming catalyst containing at least two alkali metals, alkaline earth metals, or a mixture of alkali metals and alkaline earth metals.

[0006] CN105621464A discloses a method for synthesizing aluminum oxide. This method involves mixing carbon black with an aluminum salt solution, stirring and ultrasonically treating the mixture, followed by sequentially exposing the mixture to a nitrogen atmosphere and then an oxygen atmosphere to produce aluminum oxide. CN105600810A discloses a method for preparing a macroporous aluminum oxide material. This method involves mixing carbon black with an alkaline solution, stirring the mixture, then preparing an aluminum salt solution, mixing the filtered and dried carbon black with the aluminum salt solution, stirring the mixture, ultrasonically treating the mixture, and then adding an ammonium salt. The mixture is then dried and subsequently subjected to sequential treatment in nitrogen, oxygen, and nitrogen atmospheres to produce aluminum oxide.

[0007] CN110935458A discloses a method for preparing a hydrodemetallization catalyst. After a carrier is formed, the formed product is first calcined in a nitrogen atmosphere and then in an oxygen-containing atmosphere to obtain an alumina carrier. When the carrier is calcined in a nitrogen atmosphere, the polyol or sugar compound carbonizes at the rod-shaped alumina clusters. When calcined in an oxygen-containing atmosphere, the formed carbon rapidly oxidizes and combusts, releasing heat. This causes the temperature around the rod-shaped alumina clusters to rise rapidly above the calcination temperature, further growing the alumina grains around the rod-shaped alumina clusters and increasing the macropore content in the carrier.

[0008] CN108686713A discloses an alumina support, a preparation method thereof, a dehydrogenation catalyst, and its application. The preparation method of the alumina support comprises the following steps: (1) contacting pseudo-boehmite with a low-carbon alcohol and performing solid-liquid separation; (2) drying and calcining the solid product obtained by solid-liquid separation under an inert atmosphere to obtain the alumina support. This technical solution has the advantage of producing an alumina support with a large specific surface area, large pore volume, and uniform pore size distribution, which is more conducive to the dispersion of active metal components.

[0009] With the transformation and upgrading of refining and chemical business, many reforming units that produce gasoline have been transformed to mainly produce aromatics. For reforming units that produce aromatics, they are usually operated under high severity (high reaction temperature, low hydrogen-to-oil ratio). High severity operating conditions aggravate the aggregation of platinum atoms in the catalyst, which will cause the product selectivity to deteriorate and affect the service life of the catalyst. Therefore, high severity operating conditions put forward higher requirements on the performance of reforming catalysts. Developing a new type of continuous reforming catalyst and its preparation method to meet the high severity reaction process requirements of catalytic reforming has become one of the problems to be solved in this field. Summary of the Invention

[0010] To address the above technical issues, the present invention provides a continuous reforming catalyst, its preparation method, and its application. The continuous reforming catalyst prepared by the present invention exhibits strong interactions between the platinum atoms and the support, meeting the stringent reaction requirements of catalytic reforming.

[0011] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a continuous reforming catalyst, which comprises the following steps:

[0012] (1) preparing a Sn-containing alumina support shaped article;

[0013] (2) calcining the molded product obtained in step (1) in an atmosphere free of oxygen to obtain an alumina support;

[0014] (3) impregnating the alumina support obtained in step (2) with an impregnation solution comprising a Pt-containing compound, a K-containing compound, and a competitive adsorbent to obtain an impregnated alumina support;

[0015] (4) drying, activating, and reducing the impregnated alumina support obtained in step (3) to obtain the continuous reforming catalyst;

[0016] Wherein, based on the total mass of dry-basis alumina, the continuous reforming catalyst comprises 0.01-1 mass % of Pt, 0.01-1 mass % of Sn, 30-1000 mass ppm of K and 0.3-3.0 mass % of Cl.

[0017] In the above preparation method, preferably, in step (1), the Sn-containing alumina support shaped object is spherical.

[0018] In some embodiments of the present invention, the Sn-containing alumina support spherical molding can be prepared by methods well known in the art, such as: rolling ball method, oil-ammonia column method, hot oil column method or microfluidic forming.

[0019] The present invention does not impose any particular restrictions on the steps for preparing the Sn-containing alumina support shaped article, as long as the requirements of the present invention are met. In some embodiments of the present invention, a spherical alumina support can be prepared first, and then the Sn element can be introduced by impregnation. Alternatively, the Sn element can be introduced during the preparation of the spherical alumina support, such as during spherical rolling or during the preparation of a spherical colloid. Preferably, the Sn-containing alumina support shaped article is prepared by introducing the Sn element into a spherical colloid.

[0020] In the above-mentioned preparation method, preferably, in step (1), the Sn element is introduced into the alumina support molding by a Sn-containing compound, and the Sn-containing compound includes one or a combination of stannous bromide, stannous chloride, and tin tetrachloride. In some specific embodiments of the present invention, the Sn-containing compound can be introduced by co-gelation or co-precipitation during the preparation of the alumina support molding. It will be understood by those skilled in the art that the introduction of the Sn element into the drop ball colloid is the introduction of the Sn element by co-gelation or co-precipitation.

[0021] In some specific embodiments of the present invention, the Sn-containing compound is introduced into the alumina support molded article in the form of a solution. The present invention does not specifically limit the concentration of these solutions, which can be routinely adjusted by those skilled in the art based on the element content in the catalyst defined by the present invention.

[0022] In the above preparation method, preferably, in step (2), the oxygen-free atmosphere comprises hydrogen, a hydrogen-nitrogen mixture, nitrogen, carbon monoxide, or a carbon monoxide-nitrogen mixture. More preferably, the oxygen-free atmosphere comprises a hydrogen-nitrogen mixture, and the volume fraction of hydrogen in the hydrogen-nitrogen mixture is 5 to 95% by volume, more preferably 5 to 80% by volume, and most preferably 10 to 60% by volume.

[0023] In the above preparation method, preferably, in step (2), the atmosphere not containing oxygen is a flowing atmosphere not containing oxygen.

[0024] In the above preparation method, preferably, in step (2), the calcination temperature is 300-1100°C, more preferably 400-850°C, and even more preferably 450-700°C.

[0025] In the above preparation method, preferably, in step (2), the calcination time is 0.5 to 8 hours, more preferably 2 to 6 hours.

[0026] In the above preparation method, preferably, step (2) further comprises: after the calcination is completed, cooling the calcined product to room temperature in a flowing atmosphere, and the cooling atmosphere is the same as the calcination atmosphere.

[0027] In the above preparation method, preferably, the alumina carrier obtained in step (2) is spherical, and its diameter is 1 to 3 mm, more preferably 1.4 to 2.0 mm.

[0028] In the above preparation method, preferably, in step (3), the impregnation method can be saturated impregnation or supersaturated impregnation under vacuum or non-vacuum conditions; more preferably, the impregnation method is saturated impregnation or supersaturated impregnation under vacuum conditions.

[0029] In the above preparation method, preferably, in step (3), the liquid-to-solid volume ratio of the impregnation liquid to the alumina support is 0.5-3.

[0030] In some specific embodiments of the present invention, the impregnation process can be static or dynamic. The dynamic process refers to rotating the impregnation container during the impregnation process, and dynamic impregnation is preferred.

[0031] In the above preparation method, preferably, in step (3), the immersion temperature is 20 to 60° C., and the immersion time is 0.1 to 6 hours.

[0032] In the above preparation method, preferably, in step (3), the Pt-containing compound comprises one or a combination of chloroplatinic acid, ammonium chloroplatinate, bromoplatinic acid, platinum trichloride, tetraammine platinum nitrate, dichlorocarbonylplatinum dichloride, and dinitrodiaminoplatinum. The Pt-containing compound can be introduced into the alumina support by co-impregnation or step-by-step impregnation.

[0033] In the above preparation method, preferably, in step (3), the K-containing compound comprises one or a combination of potassium hydroxide, potassium nitrate, potassium sulfate, potassium chloride, potassium carbonate, and potassium chloroplatinate. The K-containing compound can be introduced into the alumina support by co-impregnation or step-by-step impregnation.

[0034] In the above-mentioned preparation method, preferably, in step (3), the competitive adsorbent comprises one or a combination of citric acid, hydrochloric acid, nitric acid, monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid; more preferably, the competitive adsorbent comprises hydrochloric acid and / or trichloroacetic acid. The present invention utilizes a competitive adsorbent during the impregnation process to further uniformly distribute the active component metal on the support.

[0035] In the above-mentioned preparation method, preferably, the chlorine in the continuous reforming catalyst is partially or entirely derived from the competitive adsorbent. The chlorine in the continuous reforming catalyst may also be derived from the aforementioned Sn-containing compound, Pt-containing compound, or K-containing compound. The role of chlorine in the catalyst of the present invention includes regulating the amount of catalyst acid.

[0036] In the above preparation method, in step (4), the drying can be ordinary drying or vacuum drying, preferably vacuum drying. More preferably, the vacuum drying pressure is 0.001-0.08 MPa and the vacuum drying temperature is 50-95°C.

[0037] In the above preparation method, preferably, in step (4), the activation atmosphere is air, the activation temperature is 200-650°C, more preferably 450-550°C, and the activation time is 0.5-12 hours, more preferably 1-4 hours.

[0038] In the above-mentioned preparation method, preferably, in step (4), during the activation process, water and chlorine gas or chlorine-containing organic matter are injected, and the molar ratio of water to chlorine element is (10-120):1. More preferably, the chlorine-containing organic matter includes one or a combination of chlorinated hydrocarbons such as dichloroethane, carbon tetrachloride, and tetrachloroethylene. The chlorine in the continuous reforming catalyst can also come from the chlorine gas or chlorine-containing organic matter injected during the activation process.

[0039] Those skilled in the art will appreciate that, since the present invention can introduce the Pt-containing compound and the K-containing compound into the alumina support by co-impregnation or step-by-step impregnation, the impregnation solution described herein can include an impregnation solution containing the Pt-containing compound and an impregnation solution containing the K-containing compound, or can also include an impregnation solution containing both the Pt-containing compound and the K-containing compound. The present invention does not impose any particular restrictions on the concentration of the compounds in the impregnation solution; such concentrations can be routinely adjusted by those skilled in the art based on the elemental content of the catalyst as defined herein. Furthermore, when using a step-by-step impregnation approach, the metal-loaded support can be dried and activated after each impregnation step.

[0040] In the above preparation method, in step (4), the reducing atmosphere may be hydrogen, or other reducing gases such as CO. Preferably, the reducing atmosphere is hydrogen.

[0041] In the above preparation method, preferably, in step (4), the reduction temperature is 200-650° C., more preferably 400-580° C., and the reduction time is 0.5-8 hours, more preferably 1-4 hours.

[0042] In the above preparation method, preferably, based on the total mass of dry-basis alumina as 100%, the content of Pt (calculated as the amount of the element) in the continuous reforming catalyst is 0.01-0.6 mass%, more preferably 0.1-0.4 mass%, and even more preferably 0.1-0.3 mass%.

[0043] In the above preparation method, preferably, the content of Sn (calculated as the amount of the element) in the continuous reforming catalyst is 0.1-0.6% by mass, more preferably 0.1-0.5% by mass, based on 100% of the total mass of dry-basis alumina.

[0044] In the above preparation method, preferably, the content of K (calculated as the amount of the element) in the continuous reforming catalyst is 50 to 600 ppm by mass based on the total mass of the dry-basis alumina.

[0045] In the above preparation method, preferably, based on 100% of the total mass of dry-basis aluminum oxide, the content of Cl (calculated as the amount of the element) in the continuous reforming catalyst is 0.6-2.0% by mass, more preferably 0.9-1.5% by mass.

[0046] In the above-described preparation method, the Pt in the continuous reforming catalyst may exist in a metallic state or as a compound, such as an oxide, sulfide, halide (e.g., chloride), oxyhalide (e.g., oxychloride), etc., or may exist physically or chemically bound to the support and other components of the catalyst. Preferably, the Pt in the continuous reforming catalyst exists in a metallic state. After the reduction step of the present invention, most or even all of the Pt in the catalyst is reduced to a metallic state, but a small amount of Pt in other forms may still exist.

[0047] In the above-mentioned preparation method, the Sn in the continuous reforming catalyst may exist in a metallic state or as a compound, such as an oxide, a sulfide, a halide (e.g., a chloride), an oxyhalide (e.g., an oxychloride), etc., or may exist in a physical or chemical combination with the support and other components of the catalyst. Preferably, the Sn in the continuous reforming catalyst exists in an oxidized state.

[0048] In the above preparation method, preferably, K in the continuous reforming catalyst is K + Specifically, K exists in the form of K + The morphology exists in the lattice vacancies of alumina or on the surface.

[0049] In the above-mentioned preparation method, preferably, the crystalline form of alumina in the continuous reforming catalyst includes one or a combination of γ-Al2O3, η-Al2O3 and θ-Al2O3; more preferably, the crystalline form of alumina in the continuous reforming catalyst is γ-Al2O3 or η-Al2O3, and further preferably is γ-Al2O3.

[0050] A second aspect of the present invention provides a continuous reforming catalyst, which is prepared by the above-mentioned continuous reforming catalyst preparation method; based on the total mass of dry alumina, the continuous reforming catalyst includes 0.01 to 1 mass% of Pt, 0.01 to 1 mass% of Sn, 30 to 1000 mass ppm of K and 0.3 to 3.0 mass% of Cl.

[0051] According to a specific embodiment of the present invention, preferably, based on the total mass of dry-basis alumina as 100%, the content of Pt (calculated as the amount of the element) in the continuous reforming catalyst is 0.01 to 0.6 mass%, more preferably 0.1 to 0.4 mass%, and even more preferably 0.1 to 0.3 mass%.

[0052] According to a specific embodiment of the present invention, preferably, based on 100% of the total mass of dry-basis alumina, the content of Sn (calculated as the amount of the element) in the continuous reforming catalyst is 0.1-0.6% by mass, more preferably 0.1-0.5% by mass.

[0053] According to a specific embodiment of the present invention, preferably, the content of K (calculated as the amount of the element) in the continuous reforming catalyst is 50 to 600 ppm by mass based on the total mass of dry-basis alumina.

[0054] According to a specific embodiment of the present invention, preferably, based on 100% of the total mass of dry-basis alumina, the content of Cl (calculated as the amount of the element) in the continuous reforming catalyst is 0.6-2.0% by mass, more preferably 0.9-1.5% by mass.

[0055] According to a specific embodiment of the present invention, preferably, the Pt in the continuous reforming catalyst exists in a metallic form.

[0056] According to a specific embodiment of the present invention, preferably, Sn in the continuous reforming catalyst exists in an oxidized form.

[0057] According to a specific embodiment of the present invention, preferably, K in the continuous reforming catalyst is K + Form exists.

[0058] According to a specific embodiment of the present invention, preferably, the crystalline form of alumina in the continuous reforming catalyst includes one or a combination of γ-Al2O3, η-Al2O3 and θ-Al2O3; more preferably, the crystalline form of alumina in the continuous reforming catalyst is γ-Al2O3 or η-Al2O3, and further preferably γ-Al2O3.

[0059] According to a specific embodiment of the present invention, preferably, the dispersion degree of Pt in the continuous reforming catalyst is 96-100%.

[0060] According to a specific embodiment of the present invention, preferably, the Pt dispersion of the aged catalyst obtained after the continuous reforming catalyst is treated in a hydrogen atmosphere at 700° C. for 12 hours is greater than 80%.

[0061] Generally speaking, the dispersion of Pt can be calculated by the following formula:

[0062]

[0063] Where D is the dispersion of Pt.

[0064] A third aspect of the present invention provides a use of the above-mentioned continuous reforming catalyst in the continuous reforming of naphtha to produce high-octane gasoline blending components or aromatics.

[0065] In the above application, preferably, the naphtha used includes one or a combination of straight-run gasoline, hydrocracked heavy naphtha, thermally cracked or catalytically cracked gasoline fractions, and Fischer-Tropsch gasoline.

[0066] In the above application, the naphtha used preferably includes full-boiling-range gasoline having an initial boiling point of 40-80°C and an end boiling point of 160-220°C as measured by the method of ASTM D-86, and / or naphtha having a distillation range of 60-150°C, and / or heavy naphtha having a distillation range of 100-200°C. The reforming feedstock naphtha preferably used in the present invention is rich in cycloalkanes and paraffins.

[0067] In the above application, preferably, the reaction conditions for continuous reforming of naphtha include: an absolute pressure of 100 KPa to 7 MPa, more preferably 0.35 to 2.5 MPa; a reaction temperature of 315 to 600° C., more preferably 425 to 565° C.; a hydrogen / hydrocarbon molar ratio of 1 to 10, more preferably 2 to 5; a liquid hourly space velocity (LHSV) of 0.1 to 10 hours -1 , more preferably 1 to 5 hours -1 .

[0068] In the aforementioned applications, the continuous reforming of naphtha is preferably conducted under substantially anhydrous conditions. More preferably, the water content of the reformate feed upon entering the reforming reactor should be less than 50 ppm, and most preferably less than 20 ppm. The reformate feed can be dried using conventional adsorbents, such as molecular sieves, to remove water. Alternatively, the feed can be dried using conventional fractionation equipment with appropriate steam stripping operations. Alternatively, a combination of adsorption drying and steam stripping drying can be used to remove water from the reformate feed.

[0069] The present invention provides a Pt-Sn-K continuous reforming catalyst, its preparation method, and application. The technical solution of the present invention has at least the following beneficial technical effects:

[0070] During the catalyst preparation process of the present invention, a Sn-containing alumina carrier molded article is calcined in an oxygen-free atmosphere, so that the prepared alumina carrier contains more defect sites, which have a strong anchoring effect on Pt atoms. During the high-temperature reaction of naphtha catalytic reforming and the high-temperature charring of the catalyst, the Pt atoms in the catalyst of the present invention have a strong interaction with the carrier, so the Pt atoms are less likely to aggregate. Therefore, the continuous reforming catalyst of the present invention has good selectivity, high liquid yield, low dry gas and coke generation, good catalyst stability, and long service life, and can meet the high-rigidity reaction process requirements of naphtha catalytic reforming. DETAILED DESCRIPTION

[0071] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0072] Preparation Examples 1 to 5

[0073] Preparation Examples 1 to 5 respectively provide an alumina support, which is prepared by the following steps:

[0074] 1000 g of pseudo-boehmite (produced by Sasol) and an appropriate amount of deionized water were mixed at a liquid / solid ratio of 2 and stirred at room temperature to form a slurry for 0.5 hour. 30 ml of nitric acid and a predetermined amount of stannous chloride hydrochloric acid solution were then added to the mixture so that the Sn content in the solution was 0.30% by mass relative to the dry alumina. The mixture was acidified for 2 hours to obtain a mixture. The mixture was then dripped into an oil-ammonia column to form spheres. The resulting wet spheres were solidified in ammonia water for 1 hour, filtered, washed three times with deionized water, dried at 60° C. for 6 hours, and then dried at 120° C. for 2 hours to obtain a Sn-containing alumina support shaped article.

[0075] 200 g of the Sn-containing alumina support shaped material was placed in a quartz reactor. The air was first replaced with nitrogen, then the temperature was raised to 650°C in a flowing atmosphere without oxygen and calcined for 4 hours. The temperature was then cooled to room temperature in the flowing atmosphere to obtain Sn-containing alumina supports S1 to S5. Supports S1 to S5 were all small spheres with a diameter of 1.6 ± 0.2 mm.

[0076] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of carriers S1 to S5 are shown in Table 1.

[0077] Preparation Example 6

[0078] This Preparation Example provides an alumina support, prepared using essentially the same steps as Preparation Example 2, except that the Sn content of the Sn-containing alumina support is 0.11% by mass relative to the dry alumina, and the support is calcined at 480°C in a flowing atmosphere for 6 hours to obtain Sn-containing alumina support S6. Support S6 is a pellet with a diameter of 1.6±0.2 mm.

[0079] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of carrier S6 are shown in Table 1.

[0080] Preparation Example 7

[0081] This Preparation Example provides an alumina support, prepared using essentially the same steps as Preparation Example 4, except that the Sn content of the Sn-containing alumina support was 0.41% by mass relative to the dry alumina, and the support was calcined at 800°C in a flowing atmosphere for 2 hours, yielding Sn-containing alumina support S7. Support S7 was a pellet with a diameter of 1.6 ± 0.2 mm.

[0082] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of carrier S7 are shown in Table 1.

[0083] Preparation Example 8

[0084] This preparation example provides an alumina support. The preparation steps are essentially the same as those in Preparation Example 1, except that 200 g of a Sn-containing alumina support shaped article is placed in a quartz reactor, heated to 650°C in a flowing air atmosphere, and calcined for 4 hours. The temperature is then cooled to room temperature in a flowing air atmosphere to obtain Sn-containing alumina support S8. Support S8 is a small sphere with a diameter of 1.6 ± 0.2 mm.

[0085] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of carrier S8 are shown in Table 1.

[0086] Preparation Example 9

[0087] This preparation example provides an alumina support. The preparation steps are essentially the same as those in Preparation Example 6, except that 200 g of a Sn-containing alumina support shaped article is placed in a quartz reactor. The air is first replaced with nitrogen, then the temperature is raised to 650°C in a flowing 70% by volume H₂-30% by volume N₂ mixed atmosphere and calcined at this temperature for 4 hours. Nitrogen and air replacement are then performed at 650°C, and the temperature is then cooled to room temperature in a flowing air atmosphere to obtain Sn-containing alumina support S9. Support S9 is a sphere with a diameter of 1.6±0.2 mm.

[0088] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of carrier S9 are shown in Table 1.

[0089] Preparation Example 10

[0090] This preparation example provides an alumina support prepared by the following steps: 100 g of support S7 was placed in a quartz reactor, heated to 500°C in a flowing air atmosphere, and calcined for 1 hour. The temperature was then cooled to room temperature in a flowing nitrogen atmosphere to obtain Sn-containing alumina support S10. Support S10 was a pellet with a diameter of 1.6 ± 0.2 mm.

[0091] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of the carrier S10 are shown in Table 1.

[0092] Preparation Example 11

[0093] This preparation example provides an alumina support. The preparation steps are essentially the same as those in Preparation Example 1, except that 200 g of a Sn-containing alumina support shaped material is placed in a quartz reactor. The air is first replaced with nitrogen, then the temperature is raised to 650°C in a flowing carbon monoxide atmosphere and calcined for 4 hours. The temperature is then lowered to room temperature in a flowing carbon monoxide atmosphere to obtain Sn-containing alumina support S11. Support S11 is a sphere with a diameter of 1.6 ± 0.2 mm.

[0094] The Sn content, calcination atmosphere, calcination conditions and cooling atmosphere of the carrier S11 are shown in Table 1.

[0095] Test Example 1

[0096] This test example tests the specific surface area, pore volume, pore diameter and alumina crystal phase of the supports S1 to S11 provided in Preparation Examples 1 to 11.

[0097] The structural properties of supports S1-S11 were measured at -196°C using an ASAP 2020 analyzer manufactured by Micromeritics. Prior to measurement, samples of supports S1-S11 were degassed at 300°C for 4 hours. The specific surface area and pore structure data for supports S1-S11 were obtained from adsorption and desorption isotherms using the Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods.

[0098] The alumina crystal phase of supports S1 to S11 was analyzed using a Bruker-D8 XRD analyzer with a Cu target as the light source and Kα (λ = 0.154 nm) radiation. Data were collected at 40 kV and 40 mA in the range of 5-80° (2θ) with a step size of 0.02°.

[0099] The test results are shown in Table 1.

[0100] Table 1

[0101]

[0102]

[0103] As can be seen in Table 1, the specific surface area, pore volume, and pore diameter of the support prepared by calcining in an oxygen-free atmosphere are slightly smaller than those of the support prepared by calcining in an oxygen-containing atmosphere, but the overall difference is not significant. The main factor affecting the specific surface area, pore volume, and pore diameter of the support is the calcination temperature.

[0104] Example 1

[0105] This embodiment provides a continuous reforming catalyst, which is prepared by the following steps:

[0106] 100 g of support S1 was prepared, and an impregnation solution containing chloroplatinic acid, trichloroacetic acid, hydrochloric acid, and potassium chloride was prepared in predetermined amounts. The mass contents of platinum, trichloroacetic acid, hydrochloric acid, and potassium in the impregnation solution relative to the mass of dry alumina were 0.285%, 5%, 1.2%, and 60 ppm by mass, respectively. The impregnation solution was contacted with support S1 at a liquid-to-solid volume ratio of 1.8:1 at 20°C under vacuum for 6 hours, then rotary evaporated to dryness and dried at 120°C for 12 hours to obtain a catalyst precursor. The catalyst precursor was activated in an air atmosphere at 200°C for 8 hours, then at 500°C for 4 hours, and water and carbon tetrachloride were injected at a molar ratio of H2O:Cl of 45:1 during the air activation at 500°C. After the air activation was completed, the activated catalyst precursor was reduced with hydrogen at 565°C for 0.5 hour to obtain Catalyst A.

[0107] The contents of Pt, Sn, K and Cl in Catalyst A are shown in Table 2. The contents of Pt, Sn, K and Cl in Table 2 are all calculated based on the total mass of dry aluminum oxide.

[0108] In the embodiments and comparative examples of the present invention, the contents of Pt and Sn in the catalyst were determined by X-ray fluorescence spectrometry (for specific determination methods, please refer to the literature: Gao Ping, Gu Ruojing. Determination of platinum, europium and cerium in reforming catalysts by X-ray fluorescence spectrometry [J]. Analysis Laboratory, 2002(06): 80-82.), and the K content was determined by inductively coupled plasma emission spectrometry (ICP) (before determination, the catalyst sample was microwave digested with HNO3 / H2O2, and double distilled water was used for solution preparation). The chlorine content in the catalyst was determined in accordance with the standard SH / T 0343-1992 Determination of chlorine content in catalysts (ion selective electrode method).

[0109] Example 2

[0110] This embodiment provides a continuous reforming catalyst, the preparation method of which is basically the same as that of Example 1, except that the carrier used is 100g of carrier S2, and the mass content of potassium in the impregnation solution is 200 mass ppm relative to the mass of dry basis alumina, to obtain catalyst B.

[0111] The contents of Pt, Sn, K and Cl in Catalyst B are shown in Table 2.

[0112] Example 3

[0113] This embodiment provides a continuous reforming catalyst, which is prepared by the following steps:

[0114] 100 g of carrier S3 was prepared, and a potassium carbonate impregnation solution was prepared according to a predetermined amount, wherein the mass content of potassium in the impregnation solution was 350 ppm by mass relative to the mass of dry alumina; the potassium carbonate impregnation solution was sprayed on the carrier S3 by saturation impregnation, and then dried at 120° C. for 6 hours, and then activated at 550° C. in an air atmosphere for 4 hours to obtain the K-loaded carrier S3; an impregnation solution containing chloroplatinic acid and hydrochloric acid was prepared according to a predetermined amount, wherein the mass content of platinum and hydrochloric acid in the impregnation solution was 0.3% and 1.2% respectively relative to the mass of dry alumina. %; the impregnation liquid was contacted with the K-loaded carrier S3 at a liquid-to-solid volume ratio of 1.8:1 at 20°C under vacuum for 6 hours, and then rotary evaporated to dryness, and then dried at 120°C for 12 hours to obtain a catalyst precursor; the catalyst precursor was activated in an air atmosphere at 450°C for 6 hours, and water and tetrachloroethylene were injected at a H2O:Cl molar ratio of 10:1 during the air activation at 450°C. After the air activation, the activated catalyst precursor was reduced with hydrogen at 480°C for 4 hours to obtain Catalyst C.

[0115] The contents of Pt, Sn, K and Cl in Catalyst C are shown in Table 2.

[0116] Example 4

[0117] This embodiment provides a continuous reforming catalyst, the preparation method of which is basically the same as that of Example 3, except that: the carrier used is 100g of carrier S4, and the potassium hydroxide impregnation solution is prepared according to a predetermined amount, and the mass content of potassium in the impregnation solution is 600 mass ppm relative to the mass of dry alumina, to obtain Catalyst D.

[0118] The contents of Pt, Sn, K, and Cl in Catalyst D are shown in Table 2.

[0119] Example 5

[0120] This embodiment provides a continuous reforming catalyst, which is prepared by the following steps:

[0121] 100 g of carrier S5 was taken and an impregnation solution containing chloroplatinic acid, hydrochloric acid, and potassium nitrate was prepared in predetermined amounts. The mass contents of platinum, hydrochloric acid, and potassium in the impregnation solution relative to the mass of dry alumina were 0.285%, 1.7%, and 850 ppm by mass, respectively. The impregnation solution was contacted with carrier S5 at a liquid-to-solid volume ratio of 1.8:1 at 20°C under vacuum for 6 hours, then rotary evaporated to dryness and then dried at 120°C for 12 hours to obtain a catalyst precursor. The catalyst precursor was activated in a flowing air atmosphere at 520°C for 4 hours. During the air activation at 520°C, water and dichloroethane were injected at a H2O:Cl molar ratio of 50:1. After the air activation was completed, the activated catalyst precursor was reduced with hydrogen at 500°C for 2 hours to obtain Catalyst E.

[0122] The contents of Pt, Sn, K, and Cl in Catalyst E are shown in Table 2.

[0123] Example 6

[0124] This embodiment provides a continuous reforming catalyst, the preparation method of which is basically the same as that of Example 5, except that the mass contents of platinum, hydrochloric acid and potassium in the impregnation solution relative to the mass of dry alumina are 0.204%, 2.8% and 310 mass ppm, respectively, to obtain Catalyst F.

[0125] The contents of Pt, Sn, K, and Cl in Catalyst F are shown in Table 2.

[0126] Example 7

[0127] This embodiment provides a continuous reforming catalyst, which is prepared by the following steps:

[0128] Take 100g of carrier S6, and prepare an impregnation solution containing chloroplatinic acid, hydrochloric acid and potassium chloride according to predetermined amounts, the mass contents of platinum, hydrochloric acid and potassium in the impregnation solution relative to the mass of dry alumina are 0.255%, 1% and 710 mass ppm respectively; the impregnation solution and carrier S6 are brought into contact at a liquid-to-solid volume ratio of 1.8:1 at 20°C under vacuum for 6 hours, then rotary evaporated to dryness, and then dried at 120°C for 12 hours to obtain a catalyst precursor; the catalyst precursor is activated in a flowing air atmosphere at 510°C for 4 hours, and water and tetrachloroethylene are injected at a H2O:Cl molar ratio of 20:1 during the air activation at 510°C. After the air activation is completed, the activated catalyst precursor is reduced with hydrogen at 480°C for 4 hours to obtain catalyst G.

[0129] The contents of Pt, Sn, K, and Cl in Catalyst G are shown in Table 2.

[0130] Example 8

[0131] This embodiment provides a continuous reforming catalyst, the preparation method of which is basically the same as that of Example 5, except that: the carrier used is 100g of carrier S7, and the mass contents of platinum, hydrochloric acid and potassium in the impregnation solution relative to the mass of dry alumina are 0.104%, 1.8% and 100 mass ppm, respectively, to obtain Catalyst H.

[0132] The contents of Pt, Sn, K, and Cl in Catalyst H are shown in Table 2.

[0133] Example 9

[0134] This embodiment provides a continuous reforming catalyst, which is prepared by the following steps:

[0135] Take 100g of carrier S11, and prepare an impregnation solution containing chloroplatinic acid, hydrochloric acid and potassium chloride according to predetermined amounts, wherein the mass contents of platinum, hydrochloric acid and potassium in the impregnation solution are 0.285%, 1.2% and 200 mass ppm relative to the mass of dry alumina, respectively; the impregnation solution and carrier S11 are brought into contact at a liquid-to-solid volume ratio of 1.8:1 at 20°C under vacuum for 6 hours, then rotary evaporated to dryness, and then dried at 120°C for 12 hours to obtain a catalyst precursor; the catalyst precursor is activated in a flowing air atmosphere at 510°C for 4 hours, and water and tetrachloroethylene are injected at a H2O:Cl molar ratio of 60:1 during the air activation at 510°C. After the air activation is completed, the activated catalyst precursor is reduced with hydrogen at 480°C for 4 hours to obtain catalyst I.

[0136] The contents of Pt, Sn, K and Cl in Catalyst I are shown in Table 2.

[0137] Comparative Example 1

[0138] This comparative example provides a continuous reforming catalyst, which is prepared by the following steps: 100 g of carrier S8 is taken and catalyst R is prepared according to the steps in Example 3.

[0139] The contents of Pt, Sn, K, and Cl in Catalyst R are shown in Table 2.

[0140] Comparative Example 2

[0141] This comparative example provides a continuous reforming catalyst, which is prepared by the following steps: 100 g of carrier S9 is taken and catalyst S is prepared according to the steps in Example 7.

[0142] The contents of Pt, Sn, K and Cl in Catalyst S are shown in Table 2.

[0143] Comparative Example 3

[0144] This comparative example provides a continuous reforming catalyst, which is prepared by the following steps: 100 g of carrier S10 is taken and catalyst T is prepared according to the steps in Example 8.

[0145] The contents of Pt, Sn, K, and Cl in Catalyst T are shown in Table 2.

[0146] Table 2

[0147] catalyst carrier Pt, mass% Sn, mass% K, mass ppm Cl, mass% Example 1 A S1 0.28 0.30 51 1.20 Example 2 B S2 0.28 0.30 193 1.21 Example 3 C S3 0.28 0.30 345 1.35 Example 4 D S4 0.28 0.30 596 1.20 Example 5 E S5 0.28 0.30 845 1.13 Example 6 F S5 0.20 0.30 303 1.42 Example 7 G S6 0.25 0.11 700 1.05 Example 8 H S7 0.10 0.41 91 1.19 Example 9 I S11 0.28 0.30 195 1.05 Comparative Example 1 R S8 0.28 0.30 343 1.33 Comparative Example 2 S S9 0.25 0.11 702 1.06 Comparative Example 3 T S10 0.10 0.41 90 1.18

[0148] Test Example 2

[0149] This test case tests the platinum dispersion of fresh and aged catalysts.

[0150] The aging treatment of the catalyst is carried out according to the following method: 10 grams of fresh catalyst (i.e., the reduced catalysts A to I and R to T provided in the examples and comparative examples) are placed in a reactor and treated in a hydrogen atmosphere at 700° C. for 12 hours to obtain an aged catalyst.

[0151] This test example was carried out according to the following method: 0.5 g of fresh catalyst or aged catalyst with a mesh size of 20 to 40 was taken and loaded into a U-shaped tube. The temperature was raised to 500°C at a rate of 15°C / min in an Ar-H2 gas flow containing 5 volume % H2 at a flow rate of 30 ml / min, and then reduced for 1 hour, and then cooled to the program set temperature; the pipeline and the U-shaped tube were purged with He gas at a flow rate of 30 ml / min for 45 minutes, and a He-O2 gas flow containing 5 volume % O2 at a flow rate of 30 ml / min was used as the loop gas for oxygen titration; then the pipeline and the U-shaped tube were purged with Ar gas at a flow rate of 30 ml / min for 45 minutes, and a hydrogen titration was carried out using a Ar-H2 gas flow containing 5 volume % H2 at a flow rate of 30 ml / min as the loop gas.

[0152] The platinum dispersion was calculated according to the following formula:

[0153]

[0154] Where D is the Pt dispersion; V H is the total volume of the sample under standard conditions of H2 consumption, ml; 22414 is the standard volume of gas, ml / mol; M Pt is the relative atomic mass of Pt, i.e. 195 g / mol; W is the mass of the catalyst sample, g; P is the mass fraction of Pt in the catalyst, %.

[0155] The platinum dispersion of the fresh catalyst and the aged catalyst is shown in Table 3.

[0156] Table 3

[0157]

[0158] It can be seen from the platinum dispersion data in Table 3 that, for fresh catalysts, there is little difference between the catalysts of the embodiments of the present invention and the catalysts of the comparative example; however, after the catalysts are aged at high temperatures, the degree of platinum aggregation in the catalysts of the comparative example increases, while the platinum metal in the catalysts of the embodiments of the present invention has better thermal stability at high temperatures.

[0159] Test Example 3

[0160] This test example examines the reaction performance of the aged catalyst.

[0161] In a 100 mL apparatus, 50 mL of aged catalyst (the catalyst aging method is the same as in Test Example 2) was loaded, and straight-run naphtha with a distillation range of 77-175°C was used as the feed oil. The properties of the feed oil are shown in Table 4. The catalyst evaluation conditions were: reaction pressure of 0.35 MPa, reaction temperature of 505°C, and liquid feed volumetric space velocity of 2 h. -1 The hydrogen / hydrocarbon molar ratio was 3.7. The evaluation results are shown in Table 5. The carbon deposit on the catalyst was measured by a CS-744 sulfur-carbon analyzer produced by LECO.

[0162] Table 4 Properties of crude oil

[0163]

[0164] Table 5 Evaluation results of aged catalyst

[0165] catalyst <![CDATA[C5 + Yield, m%]]> Aromatic yield, m% Catalyst carbon deposition, m% A 84.7 63.5 3.66 D 84.8 63.6 3.63 E 83.7 62.8 3.94 I 84.6 63.2 3.77 C 86.7 64.5 1.72 R 80.6 60.0 6.19 G 86.8 65.0 1.53 S 81.2 60.9 5.84 H 84.6 63.1 3.79 T 82.0 61.6 5.37

[0166] As can be seen from the results in Table 5, for the aged catalyst, the catalyst of the embodiment of the present invention has higher liquid yield and aromatics yield, and lower coke yield than the catalyst of the comparative example. The catalyst exhibits better activity and stability and can meet the high-severity reaction process requirements of naphtha catalytic reforming.

Claims

1. A method for preparing a continuous reforming catalyst, comprising the following steps: (1) Preparing a Sn-containing alumina support shaped article; (2) calcining the molded product obtained in step (1) in an atmosphere free of oxygen, and after calcination, cooling the calcined product to room temperature in a flowing atmosphere, the cooling atmosphere being the same as the calcination atmosphere, to obtain an alumina carrier; (3) impregnating the alumina support obtained in step (2) with an impregnation solution comprising a Pt-containing compound, a K-containing compound, and a competitive adsorbent to obtain an impregnated alumina support; (4) drying, activating, and reducing the impregnated alumina support obtained in step (3) to obtain the continuous reforming catalyst; The continuous reforming catalyst comprises, based on the total mass of dry-basis alumina, 0.01-1 mass % of Pt, 0.01-1 mass % of Sn, 30-1000 mass ppm of K, and 0.3-3.0 mass % of Cl.

2. The preparation method according to claim 1, wherein In step (1), the Sn-containing alumina support shaped object is spherical.

3. The preparation method according to claim 1, wherein In step (1), the Sn-containing alumina support shaped article is prepared by introducing Sn element into the drop ball colloid.

4. The preparation method according to claim 1 or 3, wherein In step (1), the Sn element is introduced into the alumina support molding via a Sn-containing compound, wherein the Sn-containing compound comprises one or a combination of stannous bromide, stannous chloride and tin tetrachloride.

5. The preparation method according to claim 1, wherein In step (2), the oxygen-free atmosphere includes hydrogen, a hydrogen-nitrogen mixture, nitrogen, carbon monoxide, or a carbon monoxide-nitrogen mixture.

6. The preparation method according to claim 1 or 5, wherein In step (2), the oxygen-free atmosphere includes a hydrogen-nitrogen mixed gas, and the volume fraction of hydrogen in the hydrogen-nitrogen mixed gas is 5 to 95 volume %.

7. The preparation method according to claim 6, wherein In step (2), the volume fraction of hydrogen in the hydrogen-nitrogen mixed gas is 5 to 80 volume %.

8. The preparation method according to claim 7, wherein In step (2), the volume fraction of hydrogen in the hydrogen-nitrogen mixed gas is 10-60 volume %.

9. The preparation method according to claim 1, wherein In step (2), the oxygen-free atmosphere is a flowing atmosphere that does not contain oxygen.

10. The preparation method according to claim 1, wherein In step (2), the calcination temperature is 300-1100°C.

11. The preparation method according to claim 10, wherein In step (2), the calcination temperature is 400-850°C.

12. The preparation method according to claim 11, wherein In step (2), the calcination temperature is 450-700°C.

13. The preparation method according to claim 1, wherein In step (2), the calcination time is 0.5 to 8 hours.

14. The preparation method according to claim 13, wherein In step (2), the roasting time is 2 to 6 hours.

15. The preparation method according to claim 1, wherein In step (3), the impregnation method is saturated impregnation or supersaturated impregnation under vacuum or non-vacuum conditions.

16. The preparation method according to claim 15, wherein In step (3), the impregnation method is saturated impregnation or supersaturated impregnation under vacuum state.

17. The preparation method according to claim 1, wherein In step (3), the liquid-to-solid volume ratio of the impregnation liquid to the alumina support is 0.5-3.

18. The preparation method according to claim 1, wherein In step (3), the immersion temperature is 20-60° C., and the immersion time is 0.1-6 hours.

19. The preparation method according to claim 1, wherein In step (3), the Pt-containing compound includes one or a combination of chloroplatinic acid, ammonium chloroplatinate, bromoplatinic acid, platinum trichloride, tetraammine platinum nitrate, dichlorocarbonyl platinum dichloride and dinitrodiaminoplatinum.

20. The preparation method according to claim 1, wherein In step (3), the K-containing compound includes one or a combination of potassium hydroxide, potassium nitrate, potassium sulfate, potassium chloride, potassium carbonate and potassium chloroplatinate.

21. The preparation method according to claim 1, wherein In step (3), the competitive adsorbent includes one or a combination of citric acid, hydrochloric acid, nitric acid, monochloroacetic acid, dichloroacetic acid and trichloroacetic acid.

22. The preparation method according to claim 21, wherein In step (3), the competitive adsorbent includes hydrochloric acid and / or trichloroacetic acid.

23. The preparation method according to claim 1, wherein The chlorine in the continuous reforming catalyst is partially or entirely derived from the competitive adsorbent.

24. The preparation method according to claim 1, wherein In step (4), the activation atmosphere is air, the activation temperature is 200-650° C., and the activation time is 0.5-12 hours.

25. The preparation method according to claim 1, wherein In step (4), during the activation process, water and chlorine gas or chlorine-containing organic matter are injected, and the molar ratio of water to chlorine element is (10~120):

1.

26. The preparation method according to claim 25, wherein In step (4), the chlorine-containing organic matter includes one or a combination of dichloroethane, carbon tetrachloride and tetrachloroethylene.

27. The preparation method according to claim 1, wherein In step (4), the reducing atmosphere is hydrogen, the reducing temperature is 200-650° C., and the reducing time is 0.5-8 hours.

28. A continuous reforming catalyst prepared by the method for preparing a continuous reforming catalyst according to any one of claims 1 to 27; based on the total mass of dry-basis alumina, the continuous reforming catalyst comprises 0.01 to 1 mass% of Pt, 0.01 to 1 mass% of Sn, 30 to 1000 massppm of K, and 0.3 to 3.0 mass% of Cl.

29. The continuous reforming catalyst according to claim 28, wherein The content of Pt in the continuous reforming catalyst is 0.01 to 0.6 mass %, based on 100% of the total mass of the dry-basis alumina.

30. The continuous reforming catalyst according to claim 29, wherein The content of Pt in the continuous reforming catalyst is 0.1 to 0.4 mass %, based on 100% of the total mass of the dry-basis alumina.

31. The continuous reforming catalyst according to claim 28, wherein The Sn content in the continuous reforming catalyst is 0.1 to 0.6 mass %, based on 100% of the total mass of the dry-basis alumina.

32. The continuous reforming catalyst according to claim 28, wherein The content of K in the continuous reforming catalyst is 50 to 600 ppm by mass based on the total mass of the dry-basis alumina.

33. The continuous reforming catalyst according to claim 28, wherein The Cl content in the continuous reforming catalyst is 0.6 to 2.0 mass %, based on 100% of the total mass of the dry-basis alumina.

34. The continuous reforming catalyst according to claim 33, wherein The Cl content in the continuous reforming catalyst is 0.9 to 1.5% by mass, based on 100% of the total mass of the dry-basis alumina.

35. The continuous reforming catalyst according to claim 28, wherein The crystalline form of the aluminum oxide in the continuous reforming catalyst includes one or a combination of γ-Al2O3, η-Al2O3 and θ-Al2O3.

36. The continuous reforming catalyst according to claim 35, wherein The crystalline form of the aluminum oxide in the continuous reforming catalyst is γ-Al2O3 or η-Al2O3.

37. The continuous reforming catalyst according to claim 36, wherein The crystal form of the aluminum oxide in the continuous reforming catalyst is γ-Al2O3.

38. The continuous reforming catalyst according to claim 28, wherein The Pt dispersion in the continuous reforming catalyst is 96-100%. The Pt dispersion of the aged catalyst obtained after the continuous reforming catalyst is treated in a hydrogen atmosphere at 700° C. for 12 hours is greater than 80%. The Pt dispersion is calculated using the following formula: ， Where D is the dispersion of Pt.

39. Use of the continuous reforming catalyst according to any one of claims 28 to 38 in the continuous reforming of naphtha to produce high-octane gasoline blending components or aromatics.

40. The use according to claim 39, wherein The reaction conditions for continuous naphtha reforming include: absolute pressure of 100 KPa~7 MPa; reaction temperature of 315~600℃; hydrogen / hydrocarbon molar ratio of 1~10; liquid hourly space velocity of 0.1~10 hours -1 .

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