Boiling-solid composite bed heavy oil hydrogenation method

Abstract

The invention discloses a boiling-solid composite bed heavy oil hydrogenation method, which comprises: (1) mixing raw material oil and hydrogen, feeding into a boiling bed reactor to obtain a boiling bed liquid phase effluent, and controlling the content of a boiling bed hydrogenation catalyst in the boiling bed liquid phase effluent by using the weight of the liquid phase effluent as a reference, the content of the fluidized bed hydrogenation catalyst is 0.5-500 ppm; and (2) the liquid phase effluent containing the fluidized bed hydrogenation catalyst obtained in the step (1) enters a separation unit to obtain a separated solid phase substance and a separated liquid phase substance, the separated liquid phase substance enters a fixed bed reactor, and the optional separated solid phase substance is directly circulated back to the fluidized bed reactor or is regenerated and circulated back to the fluidized bed reactor. According to the method, the operation period of the boiling-solid composite bed heavy oil can be prolonged.

Description

Technical Field

[0001] This invention belongs to the field of heavy oil hydrogenation technology, and relates to a heavy oil hydrogenation process technology, particularly a method for heavy oil hydrogenation using a combination of fluidized bed and fixed bed. Background Technology

[0002] With the increasing trend of crude oil becoming heavier and of lower quality, the proportion of heavy oil components in crude oil is gradually increasing, and the processing difficulty is also gradually increasing. Heavy oil hydrotreating processes remove impurities such as sulfur, nitrogen, and metals from heavy oil through hydrogenation reactions, and convert non-ideal components such as polycyclic aromatic hydrocarbons, gums, and asphaltenes through hydrogenation, thereby increasing the hydrogen-to-carbon ratio and reducing residual carbon content, significantly improving its cracking performance. However, for lower-quality feedstocks, traditional fixed-bed heavy oil hydrotreating processes suffer from drawbacks in asphaltenes conversion and metal removal. These drawbacks include bed pressure drop, hot spots, catalyst deactivation, and rapid coking rates, all of which affect the operating cycle due to the dense packing of catalysts and their fixed metal-containing capacity.

[0003] CN115960625A discloses a fixed-bed heavy oil hydrotreating process. It includes the following steps: heavy oil feedstock is mixed with hydrogen and enters an upflow reaction zone for hydrodemetallization, followed by hydrodesulfurization, nitrogen removal, and residual carbon removal in a fixed-bed reaction zone. The upflow reaction zone utilizes both ultrasonic and microwave stimulation. At regular intervals, the actual metal deposition on the upflow catalyst is measured, and the ultrasonic and microwave power is adjusted accordingly. This invention maintains the bed expansion rate in the upflow reaction zone within an ideal range through a special control method, reducing the radial temperature difference, slowing down the catalyst deactivation rate in the upflow reaction zone, and improving the operating cycle of the fixed-bed heavy oil hydrotreating unit. While the process uses an upflow fixed-bed reactor and reduces catalyst deactivation by adjusting ultrasonic and microwave power to improve operating cycle, the method is difficult to operate and requires periodic measurement of the actual metal deposition, thus not fundamentally overcoming the limitations of the fixed-bed reactor itself.

[0004] Among existing heavy oil hydrotreating technologies, the fluidized bed process, compared to the fixed bed process, offers advantages such as smaller bed temperature differences, uniform pressure drop, and longer operating cycles due to the fluidized bed system's circulating fluidization. Compared to the slurry bed process, the fluidized bed process boasts better product quality, more flexible operation, and higher technological maturity. Therefore, the fluidized bed reactor, acting as a protective reactor, efficiently removes metals and asphaltenes at lower conversion rates, significantly improving the properties of feedstocks in fixed beds. Meanwhile, the fixed bed reactor fully leverages the advantages of deep refining, ensuring long-term operation of the unit and providing high-quality feedstocks for subsequent processes. Summary of the Invention

[0005] Research results indicate that the properties of the liquid phase material obtained after treatment in a fluidized bed reactor are crucial for the long-term operation of a fixed bed reactor. To address the shortcomings of existing technologies, this invention provides a fluidized-solid composite bed heavy oil hydrogenation method, which offers advantages such as wide feedstock adaptability, stable product properties, long operating cycle, and low production cost.

[0006] This invention provides a method for hydrogenating heavy oil in a boiling-solid composite bed, the method comprising the following:

[0007] (1) The feedstock oil is mixed with hydrogen and enters the fluidized bed reactor to obtain fluidized bed liquid effluent. The content of fluidized bed hydrogenation catalyst in the fluidized bed liquid effluent is controlled by the weight of the liquid effluent. The mass content of fluidized bed hydrogenation catalyst is 0.5 to 500 ppm, preferably 0.5 to 300 ppm, and more preferably 20 to 200 ppm.

[0008] (2) The liquid effluent containing the fluidized bed hydrogenation catalyst obtained in step (1) enters the separation unit to obtain the separated solid phase and the separated liquid phase. The separated liquid phase enters the fixed bed reactor. The separated solid phase can be directly recycled back to the fluidized bed reactor or recycled back to the fluidized bed reactor after regeneration.

[0009] Furthermore, in step (1) of the above method, the properties of the feedstock oil are as follows: sulfur content ≤ 6.0 wt%, preferably 1.5–5.5 wt%; total heavy metal (Ni+V) content ≤ 500 μg / g, preferably ≤ 300 μg / g; nitrogen content ≤ 6000 μg / g; Conrad carbon residue ≤ 25 wt%, preferably ≤ 20 wt%; kinematic viscosity (100℃) 2000–8000 mmHg. 2 / s.

[0010] Furthermore, in step (1) of the above method, a fluidized bed reactor with a gas-liquid-solid three-phase separator structure is preferably used.

[0011] Furthermore, in the above process, the reaction conditions of the fluidized bed reactor are as follows: reaction temperature 370–450℃, preferably 380–420℃; reaction pressure 8–20 MPa, preferably 12–18 MPa; and reaction space velocity 0.1–3.5 h⁻¹. -1 Preferably, it is 0.5 to 2.5 hours. -1 The hydrogen-to-oil volume ratio is 200–2000 Nm. 3 / m 3 Preferably 300–1000 Nm 3 / m 3 .

[0012] Furthermore, in step (1) of the above method, the fluidized bed hydrogenation catalyst support is generally an inorganic refractory oxide, such as alumina; the metal component is generally selected from group VB or group VIII metals, such as one or more of Mo, Ni, Co, W, etc., and the promoter is generally P, F, B, Si, etc. The fluidized bed hydrogenation catalyst is spherical or strip-shaped, with a specific surface area of ​​100-250 m². 2 / g, with a pore volume of 0.5-0.8 mL / g and a total acid value of 0.3-0.6 mol / g, such as the FEM-10 catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0013] Furthermore, in step (1) of the above method, the operation process of mixing the feed oil and hydrogen and then entering the fluidized bed reactor is as follows: a) The material obtained by mixing the feed oil and hydrogen is divided into two streams, namely the first mixed feed and the second mixed feed; b) The first mixed feed and the second mixed feed obtained in step a enter the fluidized bed reactor through the gas-liquid distribution plate set above the feed inlet at the bottom of the fluidized bed reactor; the gas-liquid distribution plate is equipped with a gas-liquid distributor and a microporous membrane tube. The first mixed feed enters the fluidized bed hydrogenation reactor through the gas-liquid distributor, and the second mixed feed enters the fluidized bed hydrogenation reactor through the microporous membrane tube.

[0014] Further, in step a, the mass ratio of oil in the first mixed feed and the second mixed feed is 0.25 to 19:1, preferably 1 to 10:1.

[0015] Furthermore, in step b, the hydrogen-to-oil ratio of the first mixed feed is 300–1800 Nm. 3 / m 3 The hydrogen-to-oil ratio of the second mixed feed is 5–500 Nm. 3 / m 3 Preferably, the hydrogen-to-oil ratio of the first mixed feed is 300–1300 Nm. 3 / m 3 The hydrogen-to-oil ratio of the second mixed feed is 5–300 Nm. 3 / m 3 .

[0016] Furthermore, the gas-liquid distributor in step b is one or more of the following: bubble cap type, multi-hole coil type, and multi-hole pipe type; the orifice diameter of the gas-liquid distributor is 2-30 mm, preferably 7-20 mm.

[0017] Furthermore, the microporous membrane tube in step b is selected from one or more of spherical or cylindrical shapes; the pore size of the microporous membrane tube is 0.05-0.5 mm, preferably 0.1-0.3 mm.

[0018] Further, in step b, the gas-liquid distributors are arranged circumferentially on the gas-liquid distribution disk to form a ring, and the gas-liquid distribution disk is arranged with several rings of gas-liquid distributors axially; the microporous membrane tubes are arranged circumferentially on the gas-liquid distribution disk to form a ring, and the gas-liquid distribution disk is arranged with several rings of microporous membrane tubes axially; the several rings of gas-liquid distributors and the several rings of microporous membrane tubes are arranged concentrically on the gas-liquid distribution disk.

[0019] Furthermore, the gas-liquid distributors and the microporous membrane tubes mentioned in step b are arranged concentrically and alternately on the gas-liquid distribution plate.

[0020] Furthermore, the gas-liquid distributors mentioned in step b are evenly spaced around the gas-liquid distribution plate to form a ring.

[0021] Furthermore, in step b, the microporous membrane tubes are evenly spaced along the circumference on the gas-liquid distribution disk to form a ring.

[0022] Furthermore, in step b, the angle between the discharge direction of the gas-liquid distributor and the vertical direction of the fluidized bed reactor is 45° to 135°; the discharge direction of the microporous membrane tube is parallel to the vertical direction of the fluidized bed reactor.

[0023] Furthermore, in step (2) of the above method, the separation can be carried out by means of filtration, centrifugal separation, gravity separation, etc.

[0024] Furthermore, in step (2) of the above method, the liquid effluent containing the fluidized bed hydrogenation catalyst in step (1) enters the separation unit, which includes one or more combinations of a filter, a hydrocyclone, and an interstage separator.

[0025] Furthermore, in step (2) of the above method, regeneration includes catalyst deoiling and calcination. Operating conditions: deoiling temperature 0℃~160℃, preferably 20℃~120℃; nitrogen stripping pressure 0.1bar~1MPa, preferably 1bar~5bar; deoiling time 1h~12h, preferably 2h~5h; calcination temperature 180℃~260℃, preferably 200℃~240℃; calcination time 12h~48h, preferably 18h~36h.

[0026] Furthermore, in step (2) of the above method, the operating conditions of the fixed-bed reactor are as follows: reaction temperature 350–450℃, preferably 360–420℃; reaction pressure 8–20 MPa, preferably 12–18 MPa; reaction space velocity 0.1–1.0 h⁻¹. -1 Preferably, it is 0.2 to 0.5 h. -1 The hydrogen-to-oil volume ratio is 500–1500 Nm³.3 / m 3 Preferably 700-1200 Nm 3 / m 3 .

[0027] Furthermore, in step (2) of the above method, the catalyst in the fixed-bed reactor uses alumina as a support, and the metal component is generally selected from group VB or group VIII metals, such as one or more of Mo, Ni, Co, W, etc., and the promoter is generally P, F, B, Si, etc. The physical properties of the catalyst are as follows: specific surface area of ​​60-250 m². 2 / g, with a pore volume of 0.2–0.8 mL / g, and shapes including clover, four-leaf clover, toothed spheres, and foam discs. The preferred catalyst type is a combination of several of the following developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.: FGF-01, FGF-02, FZC-1000, FZC-1001, FZC-1002, FZC-1003, FZC-1MN, and FZC-12B-6.

[0028] Compared with the prior art, the boiling-solid composite bed heavy oil hydrogenation method of the present invention has the following advantages:

[0029] 1. Conventional fluidized bed hydrogenation processes generally require the fluidized bed hydrogenation catalyst content in the obtained fluidized bed hydrogenation liquid phase stream to be as low as possible. However, this invention breaks through conventional thinking by increasing the appropriate content of fluidized bed hydrogenation catalyst in the fluidized bed hydrogenation liquid phase stream. The fluidized bed hydrogenation catalyst in the fluidized bed hydrogenation liquid phase stream can improve the liquid-solid separation effect in the separation unit, thereby improving the quality of the feed to the fixed bed reactor and improving the long-term operation effect.

[0030] 2. This invention enables the fluidized bed reactor to be free from material level limitations, allowing heavy oil hydrogenation reactions to be carried out under conditions of high catalyst content and high space velocity. Furthermore, the use of a dual-feed method can effectively improve the fluidized bed hydrogenation treatment effect. Attached Figure Description

[0031] Figure 1 The diagram shows the distribution of the gas-liquid distribution plate at the bottom of the fluidized bed hydrogenation reactor. Figure 1 (A) shows the gas-liquid distribution plate used in the fluidized bed hydrogenation reaction unit in Example 4. Figure 1 (B) shows the gas-liquid distribution plate used in the fluidized bed hydrogenation reaction unit of Examples 1, 2, 3 and the comparative examples.

[0032] Figure 1 In (A), 1 is a gas-liquid distribution plate, 2 is a gas-liquid distributor, and 3 is a microporous membrane tube.

[0033] Figure 1 In (B), 1 is the gas-liquid distribution plate and 2 is the gas-liquid distributor.

[0034] Figure 2 This invention provides a schematic diagram of a process flow for the hydrogenation of heavy oil in a boiling-solid composite bed.

[0035] Among them, 1 is feedstock oil, 2 is hydrogen, 3 is the first mixed feed, 4 is the second mixed feed, 5 is the gas-liquid distribution plate, 6 is the fluidized bed reactor, 7 is the fluidized bed liquid effluent, 8 is the filter separator, 9 is the separated liquid phase, 10 is the separated solid phase, 11 is the catalyst regeneration system, 12 is the regenerated catalyst, 13 is the fixed bed reactor, and 14 is the composite bed generated oil. Detailed Implementation

[0036] The fluidized bed reactor used in this patent is a STRONG fluidized bed reactor independently developed by Sinopec (Dalian) Petrochemical Co., Ltd., and the fluidized bed catalyst is FEM-10 microsphere catalyst. The hydrogenation reaction operating conditions are as follows: reactor inlet hydrogen partial pressure 14 MPa, fluidized bed operating temperature 390℃, hydrogen-to-oil ratio 500 Nm³. 3 / m 3 The fixed bed operates at a temperature of 380℃ and a space velocity of 0.22 h⁻¹. -1 Hydrogen-to-oil ratio 700 Nm 3 / m 3 .

[0037] The following will be combined with the appendix Figure 2 The method of the present invention will be further described with reference to specific embodiments and comparative examples, but the following embodiments do not constitute a limitation on the method of the present invention. Figure 2 As shown, feedstock oil 1 is mixed with hydrogen 2 to obtain first mixed feed 3 and second mixed feed 4, which enter the fluidized bed reactor 6 through gas-liquid distribution plate 5. The resulting fluidized bed liquid effluent 7 enters the filter separator 8 to obtain separated liquid phase 9 and separated solid phase 10. Separated solid phase 10 enters the catalyst regeneration system 11 for catalyst regeneration, and the resulting regenerated catalyst 12 is recycled back to the fluidized bed reactor 6; separated liquid phase 9 enters the fixed bed reactor 13 to obtain composite bed product oil 14.

[0038] The specific properties of the raw material oils used in the embodiments and comparative examples of this patent are shown in Table 1.

[0039] Table 1 Properties of Crude Oil

[0040]

[0041]

[0042] Example 1

[0043] (1) After the feedstock oil and hydrogen are mixed, they enter the fluidized bed reactor through a gas-liquid distribution plate for hydrogenation pretreatment, yielding the fluidized bed liquid effluent. The fluidized bed catalyst content is 80 v%, and the fluidized bed reactor space velocity is 2.2 h⁻¹. -1 The gas-liquid distribution plate of a fluidized bed reactor is as follows: Figure 1 As shown in (B).

[0044] (2) The liquid phase effluent from the boiling bed in step (1) enters the filter separator to obtain the separated solid phase and the separated liquid phase. The properties of the intermediate are shown in Table 2.

[0045] (3) The separated solid phase obtained in step (2) is recycled back to the boiling bed reactor, and the separated liquid phase is fed into the fixed bed reactor. The properties of the oil generated by the composite bed are shown in Table 3.

[0046] Example 2

[0047] (1) After the feedstock oil and hydrogen are mixed, they enter the fluidized bed reactor through a gas-liquid distribution plate for hydrogenation pretreatment, yielding the fluidized bed liquid effluent. The fluidized bed catalyst content is 50 v%, and the fluidized bed reactor space velocity is 1.3 h⁻¹. -1 The gas-liquid distribution plate of a fluidized bed reactor is as follows: Figure 1 As shown in (B).

[0048] (2) The liquid phase effluent from the boiling bed in step (1) enters the filter separator to obtain the separated solid phase and the separated liquid phase. The properties of the intermediate are shown in Table 2.

[0049] (3) The separated solid phase obtained in step (2) is recycled back to the boiling bed reactor, and the separated liquid phase is fed into the fixed bed reactor. The properties of the oil generated by the composite bed are shown in Table 3.

[0050] Example 3

[0051] (1) After the feedstock oil and hydrogen are mixed, they enter the fluidized bed reactor through a gas-liquid distribution plate for hydrogenation pretreatment, yielding the fluidized bed liquid effluent. The fluidized bed catalyst content is 70 v%, and the fluidized bed reactor space velocity is 2.2 h⁻¹. -1 The gas-liquid distribution plate of a fluidized bed reactor is as follows: Figure 1 As shown in (B).

[0052] (2) The liquid phase effluent from the boiling bed in step (1) enters the filter separator to obtain the separated solid phase and the separated liquid phase. The properties of the intermediate are shown in Table 2.

[0053] (3) The separated solids obtained in step (2) enter the catalyst regeneration system, and the regenerated catalyst is recycled back to the fluidized bed reactor. The operating conditions of the catalyst regeneration system are as follows: deoiling temperature 120℃, nitrogen stripping pressure 2 bar, deoiling treatment time 4 h, calcination temperature 230℃, and calcination time 24 h.

[0054] (4) The separated liquid phase obtained in step (2) enters the fixed bed reactor to obtain the composite bed generated oil with properties shown in Table 3.

[0055] Example 4

[0056] (1) After the feedstock oil and hydrogen are mixed, they enter the fluidized bed reactor through a gas-liquid distribution plate for hydrogenation pretreatment, yielding the fluidized bed liquid effluent. The fluidized bed catalyst content is 85 v%, and the fluidized bed reactor space velocity is 2.2 h⁻¹. -1 The gas-liquid distribution plate of a fluidized bed reactor is as follows: Figure 1 As shown in (A), the feed ratio of the first mixed feed and the second mixed feed is 6:4, and the hydrogen-to-oil ratio of the first mixed feed is 800 Nm. 3 / m 3 The second mixed feed hydrogen-to-oil ratio is 50 Nm. 3 / m 3 .

[0057] (2) The liquid phase effluent from the boiling bed in step (1) enters the filter separator to obtain the separated solid phase and the separated liquid phase. The properties of the intermediate are shown in Table 2.

[0058] (3) The separated solids obtained in step (2) enter the catalyst regeneration system, and the regenerated catalyst is recycled back to the fluidized bed reactor. The operating conditions of the catalyst regeneration system are as follows: deoiling temperature 120℃, nitrogen stripping pressure 2 bar, deoiling treatment time 4 h, calcination temperature 230℃, and calcination time 24 h.

[0059] (4) The separated liquid phase obtained in step (2) enters the fixed bed reactor to obtain the composite bed generated oil with properties shown in Table 3.

[0060] Comparative Example

[0061] (1) After the feedstock oil is mixed with hydrogen, it enters the fluidized bed reactor through a gas-liquid distribution plate for hydrogenation pretreatment, yielding the fluidized bed liquid effluent. The fluidized bed catalyst content is 50 v%, and the fluidized bed reactor space velocity is 0.8 h⁻¹. -1 The gas-liquid distribution plate of a fluidized bed reactor is as follows: Figure 1 As shown in (B).

[0062] (2) The liquid phase effluent from the boiling bed in step (1) enters the filter separator to obtain the separated solid phase and the separated liquid phase. The properties of the intermediate are shown in Table 2.

[0063] (3) The separated solid phase obtained in step (2) is recycled back to the boiling bed reactor, and the separated liquid phase is fed into the fixed bed reactor. The properties of the oil generated by the composite bed are shown in Table 3.

[0064] Table 2 Properties of intermediates

[0065]

[0066] Table 3 Properties of atmospheric slag from composite bed hydrogenation

[0067]

Claims

1. A method for hydrogenating heavy oil in a boiling-solid composite bed, characterized in that: The method includes the following: (1) The feedstock oil is mixed with hydrogen and enters the fluidized bed reactor to obtain fluidized bed liquid effluent. The content of fluidized bed hydrogenation catalyst in the fluidized bed liquid effluent is controlled by the weight of the liquid effluent. The mass content of fluidized bed hydrogenation catalyst is 0.5 to 500 ppm, preferably 0.5 to 300 ppm, and more preferably 20 to 200 ppm. (2) The liquid effluent containing the fluidized bed hydrogenation catalyst obtained in step (1) enters the separation unit to obtain the separated solid phase and the separated liquid phase. The separated liquid phase enters the fixed bed reactor. The separated solid phase can be directly recycled back to the fluidized bed reactor or recycled back to the fluidized bed reactor after regeneration.

2. The method according to claim 1, characterized in that: In step (1), the properties of the feedstock oil are as follows: sulfur content ≤ 6.0 wt%, preferably 1.5–5.5 wt%; total heavy metal (Ni+V) content ≤ 500 μg / g, preferably ≤ 300 μg / g; nitrogen content ≤ 0.8 wt%; Conrad carbon residue ≤ 25 wt%, preferably ≤ 20 wt%; kinematic viscosity (100℃) 2000–8000 mmHg. 2 / s.

3. The method according to claim 1, characterized in that: In step (1), a fluidized bed reactor with a gas-liquid-solid three-phase separator structure is used.

4. The method according to claim 1, characterized in that: In step (1), the reaction conditions of the fluidized bed reactor are as follows: reaction temperature 370–450℃, preferably 380–420℃; reaction pressure 10–19 MPa, preferably 12–17 MPa; and reaction space velocity 0.1–3.0 h⁻¹. -1 Preferably, it is 0.5 to 1.5 hours. -1 The hydrogen-to-oil volume ratio is 200–2000 Nm. 3 / m 3 Preferably 300–1000 Nm 3 / m 3 .

5. The method according to claim 1, characterized in that: In step (1), the catalyst support for the fluidized bed hydrogenation is an inorganic refractory oxide; the metal component is selected from Group VIB or Group VIII metals.

6. The method according to claim 1, characterized in that: In step (1), the process of mixing the feedstock oil and hydrogen and then entering the fluidized bed reactor is as follows: a) The material obtained by mixing the feedstock oil and hydrogen is divided into two streams, namely the first mixed feed and the second mixed feed; b) The first mixed feed and the second mixed feed obtained in step a enter the fluidized bed reactor through the gas-liquid distribution plate set above the feed inlet at the bottom of the fluidized bed reactor; the gas-liquid distribution plate is equipped with a gas-liquid distributor and a microporous membrane tube. The first mixed feed enters the fluidized bed hydrogenation reactor through the gas-liquid distributor, and the second mixed feed enters the fluidized bed hydrogenation reactor through the microporous membrane tube.

7. The method according to claim 1, characterized in that: In step (2), the separation is carried out by at least one of filtration, centrifugal separation, and gravity separation.

8. The method according to claim 1, characterized in that: In step (2), the liquid effluent containing the fluidized bed hydrogenation catalyst from step (1) enters a separation unit, which includes one or more combinations of a filter, a hydrocyclone, and an interstage separator.

9. The method according to claim 1, characterized in that: In step (2), regeneration includes catalyst deoiling and calcination; operating conditions: deoiling temperature 0℃~160℃, preferably 20℃~120℃; nitrogen stripping pressure 0.1bar~1MPa, preferably 1bar~5bar; deoiling time 1h~12h, preferably 2h~5h; calcination temperature 180℃~260℃, preferably 200℃~240℃; calcination time 12h~48h, preferably 18h~36h.

10. The method according to claim 1, characterized in that: In step (2), the operating conditions of the fixed-bed reactor are as follows: reaction temperature 350–450℃, preferably 360–420℃; reaction pressure 10–19 MPa, preferably 14–18 MPa; and reaction space velocity 0.1–1.0 h⁻¹. -1 Preferably, it is 0.2 to 0.5 h. -1 The hydrogen-to-oil volume ratio is 500–1500 Nm³. 3 / m 3 Preferably 700-1200 Nm 3 / m 3 .

11. The method according to claim 1, characterized in that: In step (2), the catalyst in the fixed-bed reactor uses alumina as a support, and the metal component is selected from group VB or group VIII metals. The catalyst properties are as follows: specific surface area of ​​60-250 m². 2 / g, with a pore volume of 0.2-0.8mL / g, and in the form of clover, four-leaf clover, toothed ball or foam disc.

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