Process for the hydrodeolefinization of catalytically cracked gasoline

Abstract

The application provides a method for reducing olefins in catalytic cracking gasoline by hydro-upgrading, which comprises the following steps: after catalytic cracking gasoline is mixed with hydrogen, pre-hydrogenation reaction is carried out under the action of a pre-hydrogenation catalyst, diene in the catalytic cracking gasoline is selectively hydrogenated and converted into mono-olefin, and a pre-hydrogenation product is obtained; the pre-hydrogenation product is mixed with hydrogen, and hydro-upgrading reaction is carried out under the action of a hydro-upgrading catalyst, sulfur is removed, and olefins are converted into isomeric alkanes and aromatic hydrocarbons. The pre-hydrogenation catalyst and the hydro-upgrading catalyst used in the application not only have a simple preparation process, no calcination process and no nitrogen oxide emission, but also have a large number of Co(Ni)-Mo-S active sites and / or medium-strong acid. Therefore, the method for reducing olefins in catalytic cracking gasoline by hydro-upgrading of the application not only realizes deep desulfurization of catalytic cracking gasoline, greatly reduces the content of olefins and preserves the octane number, but also has the advantage of high liquid yield.

Description

Technical Field

[0001] This invention belongs to the field of clean gasoline technology for catalytic cracking, specifically relating to a method for deep hydrodesulfurization of catalytic cracking gasoline, significantly reducing olefins while maintaining octane number. Background Technology

[0002] With the increasing demand for vehicle fuel and the trend towards heavier and lower-quality crude oil, environmental pollution caused by vehicle exhaust emissions is becoming increasingly serious. Upgrading gasoline quality has become an important measure to reduce vehicle exhaust pollutant emissions. The most significant feature of gasoline quality upgrading is that, while maintaining a sulfur content of no more than 10 mg / kg, it imposes lower requirements on olefin content. Studies have shown that for every 2.5–3 vol% reduction in gasoline olefin content, the octane rating decreases by one unit, and the production cost increases by approximately 120 yuan / ton. Therefore, significantly reducing the olefin content in gasoline while maintaining its octane rating through deep desulfurization has become a major challenge that needs to be addressed in the field of clean gasoline production technology.

[0003] ExxonMobil has developed the OCT Gain process for hydrotreating catalytic cracking gasoline. First, the catalytic cracking gasoline undergoes deep hydrodesulfurization and olefin saturation on an upper catalyst bed. Then, cracking, isomerization, and alkylation reactions occur on a different catalyst in the lower bed (Catalysis Today, 2003, 86:211-263). This process produces hydrotreating gasoline with a low liquid yield.

[0004] Chinese patent CN108359495A discloses a method for upgrading high-olefin catalytic cracking gasoline. The method includes the following steps: pre-hydrogenating the catalytic cracking gasoline to obtain pre-hydrogenated catalytic cracking gasoline; dividing the pre-hydrogenated catalytic cracking gasoline into light, middle, and heavy fractions; etherifying or catalytically cracking the light fraction; solvent extracting the middle fraction to obtain olefin-rich raffinate and aromatic-rich extract oil; recovering light olefins from the extract oil to obtain light olefins and sulfur-rich oil; returning a portion of the light olefins to the solvent extraction system for backwashing, and performing catalytic cracking reprocessing or selective hydrodesulfurization on another portion of the light olefins; selectively hydrodesulfurizing the heavy fraction and sulfur-rich oil to obtain a desulfurized heavy fraction. This method can increase the octane number of gasoline products while reducing sulfur and olefin content, but its process is complex.

[0005] Chinese patent CN114075453A discloses a method for hydrotreating catalytic cracking gasoline. First, full-range catalytic cracking gasoline is pre-hydrogenated in a pre-hydrogenation reactor to remove dienes, thiols, and thioethers. Then, the pre-hydrogenated product undergoes selective hydrodesulfurization in the presence of a hydrodesulfurization and isomerization catalyst, while straight-chain olefins are isomerized into branched-chain olefins or branched-chain alkanes, resulting in ultra-low sulfur clean gasoline. However, this method suffers from problems such as multiple preparation steps, nitrogen oxide emissions during roasting, and strong interactions (low activity) between the active metal and its support. This strong interaction leads to the active metal precursor covering some acidic sites and inhibits the formation of the highly active Co(Ni)-Mo-S II type active phase. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention, by adjusting the molar ratio of complexing agent / Co(Ni) and the pH value of the impregnation solution, and employing a "one-impregnation, no-burning" catalyst preparation process, not only increases the number of Co(Ni)-Mo-S active sites in the catalyst but also increases the amount of strong acid, strengthening the synergistic effect between the metal active sites and acidic active sites. This provides a simple method for preparing high-performance pre-hydrogenation catalysts and hydrotreating catalysts. The method for hydrotreating and reducing olefins in catalytic cracking gasoline using this invention, employing both pre-hydrogenation and hydrotreating catalysts, achieves deep desulfurization of catalytic cracking gasoline, significantly reduces olefin content, and maintains its octane number (RON), while also offering the advantage of high product yield.

[0007] To achieve the above objectives, this invention discloses a method for hydrotreating and reducing olefins in catalytic cracking gasoline, the method comprising the following steps:

[0008] Catalytic cracked gasoline is mixed with hydrogen and then subjected to a pre-hydrogenation reaction under the action of a pre-hydrogenation catalyst. During this reaction, dienes are selectively hydrogenated to mono-olefins, yielding a pre-hydrogenated product. This pre-hydrogenated product is then mixed with hydrogen and subjected to a hydroreforming reaction under the action of a hydroreforming catalyst. This process desulfurizes the hydrocarbons and converts the olefins into isoalkanes and aromatics. The pre-hydrogenation catalyst and / or hydroreforming catalyst are obtained by adjusting the pH of a co-impregnation solution containing a complexing agent and an active metal CoMo or NiMo salt to be greater than 8.1, preferably greater than 8.2. The molar ratio of the complexing agent to the active metal Co or Ni in the co-impregnation solution is 1.2-2.2. An equal volume of the co-impregnation solution is then impregnated onto a support, followed by aging, drying, and sulfidation.

[0009] The pre-hydrogenation catalyst and / or hydromodification catalyst are prepared by the following steps:

[0010] (1) Prepare a co-impregnation solution containing a complexing agent and an active metal salt CoMo or NiMo, and adjust the pH of the co-impregnation solution to be greater than 8.1, preferably greater than 8.2, and the molar ratio of the complexing agent to the active metal Co or Ni in the co-impregnation solution is 1.2-2.2;

[0011] (2) The co-impregnation solution from step (1) is impregnated onto the carrier, and after aging and drying, a single-impregnation non-calcination semi-finished product is obtained.

[0012] (3) The one-dip non-calcined semi-finished product from step (2) is sulfided to obtain a pre-hydrogenated catalyst and / or a hydrogenated catalyst.

[0013] The method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention includes, but is not limited to, at least one of alumina, amorphous acidic silica-alumina material, and molecular sieve.

[0014] In the method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention, when the active metal in step (1) is NiMo, step (3) yields a pre-hydrogenation catalyst.

[0015] In the method for hydrotreating and reducing olefins of catalytic cracking gasoline of the present invention, when the active metal in step (1) is CoMo, the hydrotreating catalyst is obtained in step (3).

[0016] In the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention, in step (1), the molar ratio of the complexing agent to the active metal Co or Ni is, but is not limited to, 1.5-1.7.

[0017] In the method for hydrotreating and reducing olefins of catalytic cracking gasoline of the present invention, in step (1), the complexing agent includes, but is not limited to, one or more of ethylenediaminetetraacetic acid (EDTA), nitric acid triacetic acid (NTA), ethylenediamine (EDA), cyclohexanediaminetetraacetic acid (CDTA), citric acid and ethylene glycol, preferably one or more of ethylenediaminetetraacetic acid, nitric acid triacetic acid, ethylenediamine and cyclohexanediaminetetraacetic acid.

[0018] In the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention, in step (1), the metal salt containing active metal Mo is one or more of ammonium heptamolybdate, ammonium tetramolybdate, and ammonium tetrathiomolybdate, preferably ammonium heptamolybdate and / or ammonium tetrathiomolybdate; the metal salt containing active metal Co is one or more of cobalt nitrate, cobalt acetate, and cobalt carbonate, preferably cobalt nitrate and / or cobalt acetate; the metal salt containing active metal Ni is one or more of nickel nitrate, nickel acetate, and nickel carbonate, preferably nickel nitrate and / or nickel acetate.

[0019] In the method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention, in step (2), the carrier includes, but is not limited to, alumina powder and acidic materials obtained by mixing, extruding, drying and calcining.

[0020] In the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention, in step (2), the alumina powder includes, but is not limited to, one or more of boehmite powder, SB powder and aluminum hydroxide powder, preferably boehmite powder and / or SB powder.

[0021] In the method for hydrotreating and reducing olefins of catalytic cracking gasoline of the present invention, in step (2), the acidic material includes, but is not limited to, at least one of H-ZSM-5, SAPO-11, Hβ and HMOR.

[0022] The method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention does not particularly limit the drying and calcination conditions in the support preparation process, and can adopt conditions commonly used in the art.

[0023] In the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention, the mass ratio of alumina powder to acidic material in the carrier is, but is not limited to, 1.5-4.0.

[0024] The method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention does not particularly limit the impregnation method in step (2). The impregnation method may be, for example, but not limited to, equal volume impregnation. The impregnation temperature may be, for example, 25°C-90°C, preferably 25°C. The impregnation solution preparation time is 0.2-4h, preferably 0.5-2h.

[0025] The method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention does not particularly limit the aging and drying conditions in step (2). For example, the drying temperature can be 110-130°C and the drying time can be 4-6 hours, but the present invention is not limited to these conditions.

[0026] The method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention does not particularly limit the sulfidation reaction process in step (3). The sulfidation is not limited to being carried out in a fixed-bed reactor. The sulfiding agent used in the sulfidation is one or more of dimethyl disulfide, carbon disulfide, methanethiol, ethanethiol, dimethyl ether, and thioether, preferably dimethyl disulfide and / or carbon disulfide. The sulfidation temperature is not limited to 270-350°C, preferably 280-300°C. The sulfidation time is not limited to 20-100 h, preferably 25-50 h. The sulfidation pressure is not limited to 1.0-3.0 MPa, preferably 1.5-2.5 MPa. The sulfidation volume hourly space velocity is not limited to 1.0-3.0 h⁻¹. -1 Preferably 1.0-2.0h -1The hydrogen / oil volume ratio of the sulfidation is, but is not limited to, 200:1-500:1, preferably 250:1-350:1.

[0027] The method for hydrotreating and reducing olefins in catalytic cracking gasoline according to the present invention may be an in-process sulfurized catalyst or an external sulfurized catalyst, preferably an external sulfurized catalyst.

[0028] The method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention, wherein the pre-hydrogenation catalyst and / or hydrotreating catalyst, based on a total mass of 100%, contain the following active metals in the catalyst, calculated as oxides: Co2O3 or NiO 2.0-20.0 wt%; MoO3 0.2-28.0 wt%, preferably Co2O3 or NiO 3.0-15.0 wt%; MoO3 2.0-20.0 wt%.

[0029] The method for hydrotreating and reducing olefins in catalytic cracking gasoline according to the present invention, wherein the surface Mo of the pre-hydrogenation catalyst and / or the hydrotreating catalyst is... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of S to (Co(Ni)+Mo) is not limited to 60-100%, with a preferred ratio of 65-100%; the ratio of S to (Co(Ni)+Mo) is not limited to 1.0-3.0, with a preferred ratio of 1.6-2.5; the amount of moderately strong acid is not limited to 460-1000 μmol / g, with a preferred amount of 480-800 μmol / g.

[0030] The method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention, wherein the average length of the MoS2 wafers of the pre-hydrogenation catalyst and / or the hydrotreating catalyst is, but is not limited to, 3.0-5.0 nm, preferably 3.5-4.5 nm; and the average number of stacked layers of the MoS2 wafers is, but is not limited to, 3.0-4.5, preferably 3.5-4.0.

[0031] The method for catalytic cracking gasoline hydrotreating and olefin reduction of the present invention includes a pre-hydrogenation reaction temperature including but not limited to 80-160°C, an operating pressure including but not limited to 1.5-2.5 MPa, and a volume hourly space velocity including but not limited to 1.0-4.0 h⁻¹. -1 The hydrogen / oil volume ratio is, but is not limited to, (2-10) / 1; the preferred inlet temperature is 90-140℃; the operating pressure is 1.8-2.2 MPa; and the volume hourly space velocity is 1.5-3.0 h⁻¹. -1 The hydrogen / oil volume ratio is (3-7) / 1.

[0032] The method for hydrotreating and reducing olefins in catalytic cracking gasoline according to the present invention includes a hydrotreating reaction temperature including but not limited to 280-370°C, an operating pressure including but not limited to 1.5-2.5 MPa, and a volume hourly space velocity including but not limited to 1.0-2.2 h⁻¹. -1 The hydrogen / oil volume ratio is, but is not limited to, (100-500) / 1, with a preferred inlet temperature of 290-360℃, an operating pressure of 1.8-2.2 MPa, and a volume hourly space velocity of 0.8-2.0 h⁻¹. -1 The hydrogen / oil volume ratio is (200-400) / 1.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The pre-hydrogenation catalyst and the hydro-repair catalyst used in the catalytic cracking gasoline hydrorepair and olefin reduction method of the present invention are prepared by adjusting the molar ratio of complexing agent / Co(Ni) and the pH value of impregnation solution. The preparation process is simple, there is no roasting process and no nitrogen oxide emission, and it has a large number of Co(Ni)-Mo-S active sites and / or medium-strong acid content.

[0035] (2) The method of hydrogenating and reducing olefins of catalytic cracking gasoline of the present invention can not only simultaneously achieve the goals of deep desulfurization of catalytic cracking gasoline, significantly reduce olefin content and maintain its octane number, but also has the advantage of high product liquid yield. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the catalytic cracking gasoline hydrotreating process used in the comparative examples and embodiments of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0038] Figure 1 This is a schematic diagram of the catalytic cracking gasoline hydrotreating process used in the comparative examples and embodiments of the present invention. The pre-hydrogenation reactor and the hydrotreating reactor respectively employ the pre-hydrogenation catalyst and the hydrotreating catalyst of the present invention, or respectively employ the comparative pre-hydrogenation catalyst and the comparative hydrotreating catalyst. The hydrotreating feedstock is catalytic cracking gasoline with a sulfur content of 220 ppm, an olefin content of 20.1 v%, and a research octane number (RON) of 90.9.

[0039] Evaluation and analysis methods:

[0040] (1) SH / T 0689-2000 is used to determine the total sulfur content of catalytic cracking gasoline and its hydrotreated products;

[0041] (2) GB / T 5487-1995 is used to determine the RON of catalytic cracking gasoline and its hydrotreated products;

[0042] (3) GB / T 11132 is used to determine the olefin content of catalytic cracking gasoline and its hydrotreated products.

[0043] Example 1

[0044] In this embodiment, EDTA was used to prepare FCC gasoline pre-hydrogenation catalyst (CAT-1) using a "one-step impregnation-no-calcination" process.

[0045] First, 686g of pseudoboehmite powder HC-07 (produced by Shandong Xingdu Chemical Co., Ltd., with an alumina loss of about 30wt%) and 32.5g of guar gum powder were mixed evenly. Then, 16.9g of concentrated nitric acid (65wt%) and 180g of deionized water were added. After thorough kneading, the mixture was extruded into 1.7mm clover strips in an extruder. After drying at 120℃ for about 4 hours and calcining at 520℃ for about 4 hours, the mixture was cooled and sieved to produce γ-Al2O3 carriers with a length of 3-10mm.

[0046] Then, at room temperature, a mixture containing 132 g EDTA (analytical grade), 93.6 g nickel nitrate (Ni(NO3)2·6H2O, analytical grade), and 29.0 g ammonium heptamolybdate ((NH4)6Mo7O) was prepared. 24 A solution containing 4H₂O (analytical grade), 80g concentrated ammonia (industrial grade), and 90g deionized water, with a pH of 9.4, and a molar ratio of EDTA to Co of 1.4, was impregnated onto 200g of γ-Al₂O₃ support in a single pass. After aging and drying, a single-pass, non-roasted semi-finished product was obtained. This semi-finished product was then loaded into a 200mL fixed-bed reactor for sulfidation. The sulfided oil was straight-run naphtha containing 1.5wt% carbon disulfide; the sulfidation pressure was 2.0MPa, the hydrogen-to-oil volume ratio was 300:1, and the sulfidation volume hourly space velocity was 1.5h⁻¹. -1 The sulfidation heating process is carried out under a nitrogen atmosphere, with the temperature increased from room temperature to 180°C at a rate of 30°C / h and held at that temperature for 2 hours. Then, the nitrogen atmosphere is switched to a hydrogen atmosphere, and the sulfidation oil is injected. The temperature is increased from 150°C to 230°C at a rate of 20°C / h and held at that temperature for 8 hours. Subsequently, the temperature is increased from 230°C to 280°C at a rate of 20°C / h and held at that temperature for 8 hours to obtain CAT-1.

[0047] The active metal content in CAT-1, calculated as oxides, is 9.7 wt% NiO, 10.2 wt% MoO3, with an atomic molar ratio of S / (Ni+Mo) of 1.8, and Mo...4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 68.5%, the average length of MoS2 wafers is 3.9 nm, and the average number of stacking layers of MoS2 wafers is 3.5.

[0048] Example 2

[0049] In this embodiment, EDTA was used to prepare FCC gasoline hydrotreating catalyst (CAT-2) using a "one-step impregnation-no-calcination" process.

[0050] First, 375g of H-ZSM-5 molecular sieve, 150g of pseudoboehmite powder HC-07 (produced by Shandong Xingdu Chemical Co., Ltd., which produces alumina with a water loss of about 30wt%), and 32.5g of guar gum powder were mixed evenly. Then, 16.9g of concentrated nitric acid (65wt%) and 180g of deionized water were added. After thorough kneading, the mixture was extruded into 1.7mm clover strips in an extruder. After drying at 120℃ for about 4 hours and calcining at 520℃ for about 4 hours, the mixture was cooled and sieved to produce γ-Al2O3-ZSM-5 carriers with a length of 3-10mm.

[0051] Then, at room temperature, a mixture containing 22.0 g EDTA (analytical grade), 15.6 g cobalt nitrate (Co(NO3)2·6H2O, analytical grade), and 14.5 g ammonium heptamolybdate ((NH4)6Mo7O) was prepared. 24 A solution of 4H₂O (analytical grade) and 84g concentrated ammonia (industrial grade), with a pH of 9.6 and a molar ratio of EDTA to Co of 1.3, was used to impregnate 200g of γ-Al₂O₃-ZSM-5 carrier in a single batch. After aging at room temperature for 5h and drying at 130℃ for 3h, a single-impregnation, non-calcined semi-finished product was obtained. This single-impregnation, non-calcined semi-finished product was then loaded into a 200mL fixed-bed reactor for vulcanization. The vulcanization conditions were the same as in Example 1. After vulcanization, CAT-2 was obtained.

[0052] The active metal content in CAT-2, calculated as oxides, is 3.8 wt% Co₂O₃, 5.0 wt% MoO₃, with an atomic molar ratio of S / (Co+Mo) of 1.8 and Mo... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 68.2%, the average length of MoS2 lamellae is 4.0 nm, the average number of stacking layers of MoS2 lamellae is 3.5, and the amount of medium strong acid is 490.0 μmol / g.

[0053] Example 3

[0054] The preparation procedure for CAT-3 in this embodiment differs from that in Example 2 in the following aspects: the molar ratio of NTA to Co is 2.2; the pH of the impregnation solution is 8.5; dimethyl disulfide is used as the sulfiding agent; the sulfidation pressure is 1.7 MPa; the hydrogen-to-oil volume ratio for sulfidation is 340:1; and the volume hourly space velocity for sulfidation is 1.8 h⁻¹. -1 .

[0055] The molar ratio of S / (Co+Mo) in CAT-3 is 1.4, and the molar ratio of Mo is... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 60.5%, the average length of MoS2 lamellae is 3.9 nm, the average number of stacking layers of MoS2 lamellae is 3.8, and the amount of medium strong acid is 490.3 μmol / g.

[0056] Example 4

[0057] The preparation procedure for CAT-4 in this embodiment differs from that in Example 2 in that: the molar ratio of EDA to Co is 1.6; the pH of the impregnation solution is 9.2; methanethiol is used as the sulfiding agent; the sulfidation pressure is 2.4 MPa; the hydrogen-to-oil volume ratio during sulfidation is 240:1; and the volume hourly space velocity (VHSV) during sulfidation is 1.2 h⁻¹. -1 .

[0058] The molar ratio of S / (Co+Mo) in CAT-4 is 1.5, and the molar ratio of Mo is... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 61.5%, the average length of MoS2 lamellae is 3.9 nm, the average number of stacking layers of MoS2 lamellae is 3.6, and the amount of medium strong acid is 490.4 μmol / g.

[0059] Example 5

[0060] The preparation procedure for CAT-5 in this embodiment differs from that in Example 2 in that: the molar ratio of CDTA to Co is 1.3; CoO is 7.0 wt%; MoO3 is 9.0 wt%; ethanethiol is used as the sulfiding agent; the sulfidation pressure is 2.3 MPa; the hydrogen-to-oil volume ratio is 260:1; and the sulfidation volume hourly space velocity is 2.0 h⁻¹. -1 .

[0061] The atomic molar ratio of S / (Co+Mo) in CAT-5 is 1.7, and the Mo content is... 4+ / (Mo 4+ +Mo 5+ +Mo 6+The ratio of ) was 67.8%, the average length of MoS2 lamellae was 4.1 nm, the average number of stacking layers of MoS2 lamellae was 3.7, and the amount of medium strong acid was 489.1 μmol / g.

[0062] Example 6

[0063] This embodiment prepares CAT-6, and the preparation procedure differs from that of Example 1 in that: the molar ratio of citric acid to Co is 1.4; NiO is 15.0 wt%; MoO3 is 5.0 wt%; and dimethyl ether is used as the sulfiding agent. The atomic molar ratio of S / (Ni+Mo) of CAT-6 is 1.7, and Mo... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 67.1%, the average length of MoS2 wafers is 3.6 nm, and the average number of stacking layers of MoS2 wafers is 3.3.

[0064] Example 7

[0065] The preparation procedure for CAT-7 in this embodiment differs from that in Example 2 in that the molar ratio of ethylene glycol to Co is 1.3; CoO is 3.0 wt%; MoO3 is 20.0 wt%; and sulfide is used as the sulfiding agent.

[0066] The atomic molar ratio of S / (Co+Mo) in CAT-7 is 1.6, and the atomic molar ratio of Mo is... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 65.8%, the average length of MoS2 lamellae is 4.5 nm, the average number of stacking layers of MoS2 lamellae is 4.0, and the amount of medium strong acid is 462.0 μmol / g.

[0067] Comparative Example 1

[0068] This comparative example does not use a complexing agent and uses a "two-step impregnation-two-step calcination" process to prepare a comparative FCC gasoline pre-hydrogenation catalyst (CAT-8). The preparation method is the same as that in Example 1, using the same support and the same sulfidation process. The difference is that the traditional "two-step impregnation-two-step calcination" process is used.

[0069] First, prepare a solution containing 29.0g of ammonium heptamolybdate ((NH4)6Mo7O). 24A solution containing 85g of concentrated ammonia (industrial grade) and 85g of deionized water was impregnated onto 200g of γ-Al₂O₃ support in equal volumes. After aging at room temperature for 3h, drying at 120℃ for 4h, and calcining at 550℃ for 4h, a first-leaching semi-finished product was obtained. Then, an aqueous solution containing 93.6g of nickel nitrate (Ni(NO₃)₂·6H₂O, analytical grade) and 160g of deionized water in equal volumes was impregnated onto the first-leaching semi-finished product. After aging at room temperature for 4h, drying at 120℃ for 4h, and calcining at 550℃ for 4h, a second-leaching semi-finished product was obtained. Finally, the second-leaching semi-finished product was loaded into a fixed-bed reactor for sulfidation. After sulfidation, the pre-hydrogenation catalyst CAT-8 was obtained. The active metal content of this pre-hydrogenation catalyst, calculated as oxides, is NiO 9.7wt%, MoO₃ 10.2wt%, S / (Ni+Mo) atomic molar ratio 1.0, and Mo 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 55.8%, the average length of MoS2 wafers is 4.8 nm, and the average number of stacking layers of MoS2 wafers is 4.2.

[0070] Comparative Example 2

[0071] This comparative example does not use a complexing agent and employs a "two-step impregnation-two-step calcination" process to prepare a comparative FCC gasoline hydrotreating catalyst (CAT-9). The preparation method is the same as in Example 2, using the same support and the same sulfidation process. The difference is the use of the traditional "two-step impregnation-two-step calcination" process. First, a mixture containing 14.5g of ammonium heptamolybdate ((NH4)6Mo7O) was prepared. 24 A solution containing 4g of cobalt nitrate (Co(NO3)2·6H2O, analytical grade), 40g of concentrated ammonia (industrial grade), and 40g of deionized water was impregnated onto 200g of γ-Al2O3-ZSM-5 support by equal volumes. After aging at room temperature for 3h, drying at 120℃ for 4h, and calcining at 550℃ for 4h, a first-leaching semi-finished product was obtained. Then, an aqueous solution containing 15.6g of cobalt nitrate (Co(NO3)2·6H2O, analytical grade) and 80g of deionized water was impregnated onto the first-leaching semi-finished product by equal volumes. After aging at room temperature for 4h, drying at 120℃ for 4h, and calcining at 550℃ for 4h, a second-leaching semi-finished product was obtained. Finally, the second-leaching semi-finished product was loaded into a fixed-bed reactor for sulfidation. After sulfidation, the hydrotreating catalyst CAT-9 was obtained. The active metal content of this hydrotreating catalyst, calculated as oxides, is: Co2O3 3.8wt%, MoO3 5.0wt%, S / (Co+Mo) atomic molar ratio 1.1, Mo... 4+ / (Mo 4+ +Mo 5+ +Mo 6+The ratio of ) is 55.9%, the amount of medium strong acid is 308.2 μmol / g, the average length of MoS2 lamellae is 4.6 nm, and the average number of stacking layers of MoS2 lamellae is 4.1.

[0072] Comparative Example 3

[0073] The preparation procedure for CAT-10 in this comparative example differs from that of CAT-1 in Example 1 in that the molar ratio of EDTA to Ni is 1.2, and the pH of the impregnation solution is 8.0. The active metal content in CAT-10, calculated as oxides, is 9.7 wt% NiO, 10.2 wt% MoO3, and the atomic molar ratio of S / (Ni+Mo) is 1.5, with Mo... 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 60.3%, the average length of MoS2 wafers is 4.1 nm, and the average number of stacking layers of MoS2 wafers is 3.6.

[0074] Comparative Example 4

[0075] The comparative example of preparing the hydrotreating catalyst (CAT-11) differs from the preparation procedure of CAT-2 in Example 2 in that the molar ratio of EDTA to Co is 1.2, and the pH of the impregnation solution is 8.0. The active metal content in CAT-11, calculated as oxides, is 3.8 wt% Co₂O₃, 5.0 wt% MoO₃, with an atomic molar ratio of S / (Co+Mo) of 1.5 and Mo… 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) is 60.2%, the average length of MoS2 lamellae is 4.2 nm, the average number of stacking layers of MoS2 lamellae is 3.6, and the amount of medium strong acid is 480.0 μmol / g.

[0076] Example 8

[0077] This embodiment compares and evaluates the CAT-1 / CAT-2 of the present invention with the comparative examples CAT-8 / CAT-9 / CAT-10 / CAT-11. The parameters of the comparative evaluation process are shown in Table 1, and the comparative evaluation results are shown in Table 2.

[0078] Table 1 Main operating parameters of the reactor

[0079] reactor Inlet temperature, °C Inlet pressure, MPa Hydrogen-to-oil ratio, v / v <![CDATA[Space velocity, h -1 > Pre-hydrogenation reactor 90 2.3 5.0 2.6 Hydrogenation reforming reactor 340 1.7 300 1.5

[0080] Table 2 Evaluation results of the catalyst of the present invention and the comparative catalyst.

[0081]

[0082]

[0083] Evaluation results show that, compared with the comparative catalyst, the catalyst of this invention produces hydrogenated gasoline with higher average desulfurization rate, higher average olefin reduction, and higher average liquid yield, while exhibiting lower average RON loss. This is attributed to the fact that the catalyst prepared by the method of this invention has a higher S / (Co+Mo) atomic molar ratio and Mo compared with the catalyst prepared by the comparative method. 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of ) and the amount of medium strong acid, the average length of shorter MoS2 lamellar crystals, and the average number of stacked layers of fewer MoS2 lamellar crystals (see Table 3).

[0084] Table 3 Characterization data of the catalyst of the present invention and the comparative catalyst.

[0085]

[0086] Example 9

[0087] The difference from Example 8 is that the main operating parameters of the reactor are different (see Table 4), and the comparative series evaluation results are shown in Table 5 below.

[0088] Table 4 Main operating parameters of the reactor

[0089]

[0090]

[0091] As shown in Table 5, compared with the catalyst of the comparative example, the catalyst of the present invention has a higher average desulfurization rate (96.2%), a higher average olefin reduction (9.2v%), a higher average liquid yield (99.8%), and a lower average RON loss (0.8%).

[0092] Table 5 Evaluation results of the catalyst of the present invention and the comparative catalyst.

[0093]

[0094] Example 10

[0095] The difference from Example 8 is that the main operating parameters of the reactor are different (see Table 6), and the comparative evaluation results are shown in Table 7 below.

[0096] Table 6 Main operating parameters of the reactor

[0097] reactor Inlet temperature, °C Inlet pressure, MPa Hydrogen-to-oil ratio, v / v <![CDATA[Space velocity, h -1 > Pre-hydrogenation reactor 120 1.8 3.0 2.1 Hydrogenation reforming reactor 330 1.4 400 1.6

[0098] As shown in Table 7, compared with the catalyst of the comparative example, the catalyst of the present invention has a higher average desulfurization rate (97.5%), a higher average olefin reduction (10.1v%), a higher average liquid yield (99.7%), and a lower average RON loss (1.0%) in the hydrogenated gasoline product.

[0099] Table 7 Evaluation results of the catalyst of the present invention and the comparative catalyst.

[0100]

[0101] Example 11

[0102] The difference from Example 8 is that the main operating parameters of the reactor are different (see Table 8), and the comparative evaluation results are shown in Table 9 below.

[0103] Table 8 Main operating parameters of the reactor

[0104] reactor Inlet temperature, °C Inlet pressure, MPa Hydrogen-to-oil ratio, v / v <![CDATA[Space velocity, h -1 > Pre-hydrogenation reactor 130 2.4 6 1.4 Hydrogenation reforming reactor 350 1.9 450 1.8

[0105] As shown in Table 9, compared with the catalyst of the comparative example, the catalyst of the present invention has a higher average desulfurization rate (99.1%), a higher average olefin reduction (12.3v%), a higher average liquid yield (99.4%), and a lower average RON loss (1.6%) in the hydrogenated gasoline product.

[0106] Table 9 Evaluation results of the catalyst of the present invention and the comparative catalyst.

[0107]

[0108] The results above show that the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention can not only simultaneously achieve the goals of deep desulfurization of catalytic cracking gasoline, significantly reduce olefin content, and maintain its octane number, but also has the advantage of high liquid yield. Furthermore, the catalyst used in the method for hydrotreating and reducing olefins in catalytic cracking gasoline of the present invention not only has a simple preparation process, no roasting process, and no nitrogen oxide emissions, but also has a large number of Co(Ni)-Mo-S active sites and a medium-strong acid content.

[0109] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for hydrotreating and reducing olefins in catalytic cracking gasoline, characterized in that, The method includes the following steps: After catalytic cracking gasoline is mixed with hydrogen, a pre-hydrogenation reaction is carried out under the action of a pre-hydrogenation catalyst. The dienes are selectively hydrogenated to mono-olefins to obtain pre-hydrogenation products. The pre-hydrogenation products are mixed with hydrogen and hydro-reforming reaction is carried out under the action of a hydro-reforming catalyst to desulfurize and convert olefins into isoalkanes and aromatics. The pre-hydrogenation catalyst and / or hydromodification catalyst are prepared by the following steps: (1) Prepare a co-impregnation solution containing a complexing agent and an active metal salt CoMo or NiMo, and adjust the pH of the co-impregnation solution to be greater than 8.

1. The molar ratio of the complexing agent to the active metal Co or Ni in the co-impregnation solution is 1.2-2.

2. (2) The co-impregnation solution from step (1) is impregnated onto the carrier, and after aging and drying, a single-impregnation non-calcination semi-finished product is obtained; (3) The one-dip non-calcined semi-finished product from step (2) is sulfided to obtain a pre-hydrogenated catalyst and / or a hydrogenated catalyst; When the active metal in step (1) is NiMo, a pre-hydrogenation catalyst is obtained; When the active metal in step (1) is CoMo, a hydrogenation catalyst is obtained; The surface Mo of the pre-hydrogenation catalyst and / or hydromodification catalyst 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of S / (Co+Mo) is 60-100%; the atomic molar ratio of S / (Co+Mo) is 1.0-3.0; the atomic molar ratio of S / (Ni+Mo) is 1.0-3.0; the amount of moderately strong acid is 460-1000 μmol / g; The average number of stacked layers of the MoS2 wafers in the pre-hydrogenated catalyst and / or the hydrogenated catalyst is 3.0-4.5; The acidic material in the support of the pre-hydrogenation catalyst and / or hydromodification catalyst includes at least one of H-ZSM-5, SAPO-11, Hβ, and HMOR.

2. The method according to claim 1, characterized in that, In step (1), the pH is greater than 8.

2.

3. The method according to claim 1, characterized in that, In the pre-hydrogenated catalyst and / or the hydrogenated catalyst, the content of active metals in the catalyst, calculated as oxides, is as follows: Co2O3 or NiO is 2.0-20.0 wt%; MoO3 is 0.2-28.0 wt%.

4. The method according to claim 3, characterized in that, In the pre-hydrogenated catalyst and / or the hydrogenated catalyst, the content of active metals in the catalyst, calculated as oxides, is as follows: Co2O3 or NiO is 3.0-15.0 wt%; MoO3 is 2.0-20.0 wt%.

5. The method according to claim 1, characterized in that, The surface Mo of the pre-hydrogenation catalyst and / or hydromodification catalyst 4+ / (Mo 4+ +Mo 5+ +Mo 6+ The ratio of S to (Co+Mo) is 65-100%; the atomic molar ratio of S / (Co+Mo) is 1.6-2.5; the atomic molar ratio of S / (Ni+Mo) is 1.6-2.5; and the amount of moderately strong acid is 480-800 μmol / g.

6. The method according to claim 1, characterized in that, The average length of the MoS2 wafers in the pre-hydrogenated catalyst and / or the hydrogenated catalyst is 3.0-5.0 nm; the average number of stacked layers in the MoS2 wafers is 3.5-4.

0.

7. The method according to claim 6, characterized in that, The average length of the MoS2 wafers of the pre-hydrogenated catalyst and / or the hydrogenated catalyst is 3.5-4.5 nm.

8. The method according to claim 1, characterized in that, The pre-hydrogenation reaction is carried out at a temperature of 80-160 °C, an operating pressure of 1.5-2.5 MPa, and a volume hourly space velocity of 1.0-4.0 h⁻¹. -1 The hydrogen / oil volume ratio is (2-10) / 1.

9. The method according to claim 8, characterized in that, The pre-hydrogenation reaction is carried out at a temperature of 90-140 °C, an operating pressure of 1.8-2.2 MPa, and a volume hourly space velocity of 1.5-3.0 h⁻¹. -1 The hydrogen / oil volume ratio is (3-7) / 1.

10. The method according to claim 1, characterized in that, The hydrogenation reaction was carried out at a temperature of 280-370 °C, an operating pressure of 1.5-2.5 MPa, and a volume hourly space velocity of 1.0-2.2 h⁻¹. -1 The hydrogen / oil volume ratio is (100-500) / 1.

11. The method according to claim 10, characterized in that, The hydrogenation reaction was carried out at a temperature of 290-360℃, an operating pressure of 1.8-2.2 MPa, and a volume hourly space velocity of 0.8-2.0 h⁻¹. -1 The hydrogen / oil volume ratio is (200-400) / 1.

12. The method according to claim 1, characterized in that, The molar ratio of the complexing agent to the active metal Co or Ni is 1.5-1.7; the complexing agent is one or more of ethylenediaminetetraacetic acid, nitric acid, ethylenediamine, cyclohexanediaminetetraacetic acid, citric acid and ethylene glycol.

13. The method according to claim 12, characterized in that, The complexing agent is one or more of ethylenediaminetetraacetic acid, aziridine triacetic acid, ethylenediamine, and cyclohexanediaminetetraacetic acid.

14. The method according to claim 1, characterized in that, The metal salt containing active metal Mo is one or more of ammonium heptamolybdate, ammonium tetramolybdate, and ammonium tetrathiomolybdate; the metal salt containing active metal Co is one or more of cobalt nitrate, cobalt acetate, and cobalt carbonate; the metal salt containing active metal Ni is one or more of nickel nitrate, nickel acetate, and nickel carbonate; and the support is at least one of alumina, amorphous acidic aluminosilicate material, and molecular sieve.

15. The method according to claim 14, characterized in that, The metal salt containing the active metal Mo is ammonium heptamolybdate and / or ammonium tetrathiomolybdate.

16. The method according to claim 14, characterized in that, The metal salt containing the active metal Co is cobalt nitrate and / or cobalt acetate.

17. The method according to claim 14, characterized in that, The metal salt containing active metal Ni is nickel nitrate and / or nickel acetate.

18. The method according to claim 1, characterized in that, The sulfiding agent used in the sulfidation process is one or more of dimethyl disulfide, carbon disulfide, methanethiol, ethanethiol, and thioethers; the sulfidation temperature is 270-350℃; the sulfidation time is 20-100 h; the sulfidation pressure is 1.0-3.0 MPa; and the sulfidation volume hourly space velocity is 1.0-3.0 h⁻¹. -1 The hydrogen / oil volume ratio of the sulfidation is 200:1-500:

1.

19. The method according to claim 18, characterized in that, The sulfiding reagent used in the sulfidation process is dimethyl disulfide and / or carbon disulfide; the sulfidation temperature is 280-300 °C; the sulfidation time is 25-50 h; the sulfidation pressure is 1.5-2.5 MPa; and the sulfidation volume hourly space velocity is 1.0-2.0 h⁻¹. -1 The hydrogen / oil volume ratio of the sulfidation is 250:1-350:1.

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