Heavy oil slurry reactor hydrocracking device

Abstract

The utility model discloses a heavy oil slurry bed hydrocracking device which comprises a heating furnace, a slurry bed reactor, a circulating pump, a circulator, a cooler, a hot separator, a cold separator and a product fractionating tower, the hot separator is provided with a circulating pump, thereby effectively reducing temperature difference in the reactor. Compared with the conventional scheme of arranging cold hydrogen, the device can reduce the flow of a circulator, reduce the differential pressure of a reaction system and reduce the overall energy consumption of the device. The bottom of the slurry bed reactor is provided with a mixed feed inlet, a hydrogen distributor and a circulating oil distributor, under the comprehensive action of the scheme, the two-phase mixing effect in the reactor is greatly enhanced, and the overall heavy oil conversion rate is increased.

Description

Technical Field

[0001] The utility model relates to the hydrocracking technology of coal tar and residual oil in the fields of coal chemical industry and petrochemical industry, and particularly relates to a heavy oil slurry bed hydrocracking device. Background Art

[0002] In recent years, with the increasing inferiority and heaviness of crude oil, the increasing demand in the consumer market for light oil products, aromatics or chemical products based on light oil products, and the increasingly strict environmental protection regulations, heavy oil upgrading technologies and heavy oil hydrocracking technologies have received more and more attention. The deep processing and upgrading of heavy oil, especially inferior residual oil / coal tar, is of great significance for the rational utilization of petroleum resources, the improvement of product quality, and the increase of light oil yield.

[0003] Heavy oil hydrocracking technology is generally divided into three types from the reactor type: fixed bed, ebullated bed, and slurry bed hydrocracking. Among them, fixed bed heavy oil hydrogenation has relatively high requirements for raw materials, such as limitations on the carbon residue content, metal content, etc., and it is not easy to process inferior heavy oil, so the technology promotion is restricted to a certain extent. The ebullated bed hydrogenation technology can process relatively inferior heavy oil, but the operating conditions are harsh and the device investment is relatively high. The slurry bed hydrocracking technology can process various inferior raw materials, with a relatively simple process and high conversion rate. In recent years, with the commissioning of several imported slurry bed technologies in China, the above advantages have also been proven by industrial performance.

[0004] CN1349554 discloses a method for hydrotreating heavy feedstock in an upflow reactor system with a layered catalyst bed. An upflow fixed bed reactor with at least two catalysts with different hydrogenation activities is used to hydrotreat heavy feedstock containing metals, sulfur, and carbonaceous residue. However, the operation cycle of this method is short, generally not exceeding 1 year.

[0005] CN00110714.3 discloses a method for treating residual oil. Before the heavy residue oil hydrogenation reaction system, a single-stage adsorption filter bed layer or a single-stage adsorption filter bed layer and a single-stage adsorption filter catalyst bed layer are used simultaneously. This can not only remove suspended particles carried in the raw oil to the greatest extent, but also remove iron naphthenate in the crude oil to form iron sulfide and most of the easily coking substances, minimizing the fouling of the residue oil reactor system and reducing the number of start-ups and shut-downs caused by fouling during the operation cycle of the device. However, this method requires the switching use of two sets of adsorption and filtration systems. For the residue oil medium, the frequent switching of the above systems is not conducive to the long-term stable operation of the device.

[0006] It can be seen from the technologies disclosed in the above patent applications that the existing heavy oil hydrocracking technologies are difficult to process inferior heavy oil with a long operation cycle and high conversion rate. Summary of the Utility Model

[0007] The purpose of the present utility model is to provide a heavy oil slurry bed hydrocracking device, which can reduce the temperature difference in the slurry bed reactor, increase the overall light oil yield, extend the operation cycle of the device, reduce the energy consumption of the device, and reduce the investment.

[0008] A heavy oil slurry bed hydrocracking device of the present utility model includes a heating furnace, a slurry bed reactor, a circulating pump, a circulating machine, a cooler, a hot separator, a cold separator, and a product fractionating tower; the heating furnace, the slurry bed reactor, the hot separator, the cooler, the cold separator, and the circulating machine are connected in sequence; the product fractionating tower is respectively connected to the hot separator and the cold separator; the hot separator, the circulating pump, and the slurry bed reactor are connected in sequence.

[0009] A heavy oil slurry bed hydrocracking device, which is further characterized in that at least one hydrogen distributor is arranged in the slurry bed reactor, and the recycled hydrogen is heated by the heating furnace and injected into the hydrogen distributor at a single point or multiple points. Under the combined action of the single-point or multi-point injection of hydrogen and the injection of the circulating oil from the bottom of the reactor, the temperature difference of the reactor is reduced, the two-phase mixing effect is strengthened, and the overall conversion rate of the reactor is improved.

[0010] A heavy oil slurry bed hydrocracking device, which is further characterized in that a circulating oil distributor is arranged at the bottom of the slurry bed reactor. The circulating oil is boosted by the circulating pump, and then mixed with the feed oil, catalyst, make-up hydrogen, and hydrogenated hydrogen, and then enters the slurry bed reactor through the circulating oil distributor. After the mixed material is distributed by the circulating oil distributor, it moves upward, and at the same time, it rotates upward as a whole to strengthen the flow of the side wall of the slurry bed reactor and reduce the dead zone.

[0011] A heavy oil slurry bed hydrocracking device, which is further characterized in that according to factors such as the device scale and conversion rate, one slurry bed reactor or multiple slurry bed reactors connected in series are arranged.

[0012] A heavy oil slurry bed hydrocracking device, which is further characterized in that the hydrogen distributor includes a hydrogen injection pipe, a cross joint pipe, and a hydrogen distribution pipe; the cross joint pipe includes four short pipes, and each short pipe is connected to hydrogen distribution pipes of different lengths in a clockwise direction. The hydrogen injection pipe is respectively connected to the center of the cross joint pipe and the outer ends of the four short pipes from top to bottom.

[0013] A heavy oil slurry bed hydrocracking device, which is further characterized in that two rows of holes are opened at the bottom of a single distribution pipe towards the slurry bed reactor, and the interval between the two rows of holes is 40-100°.

[0014] A heavy oil slurry bed hydrocracking device, which is further characterized in that the holes opened on the distribution pipe are round holes, rectangular holes, diamond holes, or square holes.

[0015] A heavy oil slurry bed hydrocracking unit, which is further characterized in that: the recycle oil distributor includes a recycle oil distribution pipe, a distribution tray, and a pre-distributor. The recycle oil distribution pipe is connected above the distribution tray, and the pre-distributor is correspondingly connected below the distribution tray; the side of the pre-distributor is provided with openings, and the opening area is 2 to 3 times the cross-sectional area of the recycle oil distribution pipe.

[0016] A heavy oil slurry bed hydrocracking unit, which is further characterized in that: the recycle oil distribution pipes are distributed in a concentric circle manner, and the recycle oil distribution pipes are arranged perpendicular to or at an inclined angle of 5 to 15° with the distribution tray; a 90° elbow is provided at the top of the recycle oil distribution pipe, and the outlet direction of the elbow is arranged tangentially to the concentric circle where it is located.

[0017] A heavy oil slurry bed hydrocracking unit, which is further characterized in that: the inner diameter range of the recycle oil distribution pipe is 15 to 32 mm.

[0018] The raw material heavy oil of the present utility model includes coal tar from a coal chemical plant, atmospheric residue and vacuum residue from a refinery atmospheric and vacuum distillation unit. The heavy oil has high contents of sulfur, nitrogen, asphaltene, metal, etc. The heavy oil and the hydrogenated mixture undergo a series of reactions such as desulfurization, demetallization, decarbonization, denitrification, and hydrocracking in the slurry bed reactor.

[0019] The beneficial effects of the present utility model are as follows:

[0020] 1) A recycle pump is provided in the hot separator, which effectively reduces the temperature difference in the reactor. Compared with the previous scheme of setting cold hydrogen, the present utility model can reduce the recycle machine flow rate, reduce the differential pressure of the reaction system, and reduce the overall energy consumption of the unit.

[0021] 2) A mixed feed inlet is provided at the bottom of the slurry bed reactor, and a recycle oil distributor is provided inside the mixed feed inlet. The gas-liquid two-phase medium enters the distributor from the side at the bottom and flows out through the distribution pipe. The distribution pipes are evenly arranged on the distribution tray, and the logistics forms a swirling flow as a whole, strengthening the fluid flow on the reactor side wall. At the same time, a hydrogen distributor is provided, and hydrogen enters from the top and exits from the bottom, contacting the mixed feed reversely. It is evenly distributed in each dispersion channel of the distribution pipe and fully contacts and mixes with the two-phase feed. Under the combined action of the above schemes, the two-phase mixing effect in the reactor is greatly strengthened, and the overall heavy oil conversion rate is improved. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the present utility model;

[0023] Figure 2 It is a top view of the hydrogen distributor;

[0024] Figure 3 It is a side view of the hydrogen distributor;

[0025] Figure 4 It is a bottom view of the distribution pipe of the hydrogen distributor;

[0026] Figure 5 Top view schematic diagram of the distribution pipe layout of the circulating oil distributor

[0027] Figure 6 Side view of the circulating oil distributor

[0028] In the figure: 1. Heating furnace; 2. Slurry bed reactor; 3. Circulation pump; 4. Circulating oil distributor; 5. Circulator; 6. Cooler; 7. Thermal separator; 8. Cold separator; 9. Product fractionating tower; 10. Hydrogen distributor; 11. Hydrogen injection pipe; 12. Short pipe; 13. Hydrogen distribution pipe; 14. Circulating oil distribution pipe; 15. Distribution plate; 16. Predistributor Detailed implementation manners

[0029] The present utility model will be introduced in detail below in conjunction with the accompanying drawings:

[0030] As Figures 1 - 6 shown, the hydrogen-rich mixture composed of make-up hydrogen and part of the circulating hydrogen is mixed with heavy oil and catalyst, and is sent to the bottom of the slurry bed reactor 2 after being heated to the reaction temperature by the heating furnace 1. Part of the circulating hydrogen is heated by the heating furnace 1 and injected into the hydrogen distributor 10 at different heights at multiple points to strengthen the mixing effect of hydrogen, mixed feed and circulating oil. The circulating liquid at the bottom of the thermal separator 7 is sent to the circulation pump 3, and the circulating liquid after being boosted by the circulation pump 3 is mixed with heavy oil, catalyst and hydrogen-rich mixture to the circulating oil distributor 4 at the bottom of the reactor

[0031] The reaction product flows from the top of the slurry bed reactor 2 to the thermal separator 7 for flash separation. The gas phase after thermal separation is cooled by the cooler 6 and then sent to the cold separator 8. The oil phase after thermal separation and the oil phase after cold separation are sent to the product fractionating tower 9. The gas phase in the cold separator 8 is the circulating hydrogen rich in a large amount of hydrogen, which is boosted by the circulator 5. Part of the circulating hydrogen is mixed with make-up hydrogen and then mixed with heavy oil and catalyst; the other part is injected into the slurry bed reactor after being heated by the heating furnace 1. After the oil phase is rectified in the product fractionating tower 9, products such as dry gas, naphtha, diesel, wax oil and unconverted oil are separated

[0032] The hydrogen distributor 10 includes a hydrogen injection pipe 11, a cross joint pipe and a hydrogen distribution pipe 13; the cross joint pipe includes four short pipes 12, and each short pipe 12 is connected clockwise to hydrogen distribution pipes 13 with different lengths. The hydrogen injection pipe 11 is respectively connected to the center of the cross joint pipe and the outer ends of the four short pipes 12 from top to bottom. Each single distribution pipe opens two rows of round holes towards the bottom of the slurry bed reactor, and the two rows of round holes are spaced 70° apart

[0033] The circulating oil distributor 4 includes a circulating oil distribution pipe 14, a distribution disc 15, and a pre-distributor 16. The circulating oil distribution pipe 14 is connected above the distribution disc 15, and the pre-distributor 16 is correspondingly connected below the distribution disc 15. The side of the pre-distributor 16 is provided with openings, and the opening area is 2 to 3 times the cross-sectional area of the circulating oil distribution pipe. The circulating oil distribution pipes are distributed in a concentric circle manner, and the circulating oil distribution pipes are arranged at an angle of 10° with the distribution disc. A 90° elbow is provided at the top of the circulating oil distribution pipe, and the outlet direction of the elbow is arranged tangentially to the concentric circle where it is located.

[0034] The above are only typical examples of the present invention, and there is no any formal restriction on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, the changes or modifications made using the above technical content should be regarded as equivalent examples of the same change. Any equivalent change made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A heavy oil slurry bed hydrocracking unit, characterized in that: It includes a heating furnace, a slurry bed reactor, a circulation pump, a circulation machine, a cooler, a hot separator, a cold separator and a product distillation tower; the heating furnace, the slurry bed reactor, the hot separator, the cooler, the cold separator and the circulation machine are connected in sequence; the product distillation tower is connected with the hot separator and the cold separator respectively; the hot separator, the circulation pump and the slurry bed reactor are connected in sequence.

2. A heavy oil slurry bed hydrocracking unit according to claim 1, characterized in that: At least one hydrogen distributor is arranged in the slurry bed reactor.

3. A heavy oil slurry bed hydrocracking unit according to claim 1, characterized in that: A circulating oil distributor is arranged at the bottom of the slurry bed reactor.

4. A heavy oil slurry bed hydrocracking unit according to claim 2, characterized in that: The hydrogen distributor comprises a hydrogen injection pipe, a cross pipe and a hydrogen distribution pipe; the cross pipe comprises four short pipes, each short pipe is connected to hydrogen distribution pipes of different lengths clockwise; the hydrogen injection pipe is connected to the center of the cross pipe and the outer end points of the four short pipes from top to bottom.

5. A heavy oil slurry bed hydrocracking unit according to claim 4, characterized in that: The hydrogen distribution pipe has two rows of holes opened toward the bottom of the slurry bed reactor, and the two rows of holes are spaced 40 to 100 degrees apart.

6. A heavy oil slurry bed hydrocracking unit according to claim 5, characterized in that: The openings of the hydrogen distribution pipe are circular holes, rectangular holes, diamond holes or square holes.

7. A heavy oil slurry bed hydrocracking unit according to claim 3, characterized in that: The circulating oil distributor comprises a circulating oil distribution pipe, a distribution plate, and a pre-distributor. The circulating oil distribution pipe is connected above the distribution plate, and the pre-distributor is correspondingly connected below the distribution plate. A hole is opened on the side of the pre-distributor, and the opening area is 2 to 3 times the cross-sectional area of ​​the circulating oil distribution pipe.

8. A heavy oil slurry bed hydrocracking unit according to claim 7, characterized in that: The circulating oil distribution pipe is distributed in a concentric circle manner, and is arranged perpendicular to the distribution plate or inclined at a certain angle, with an inclination angle of 5 to 15 degrees; a 90 degree elbow is provided on the top of the circulating oil distribution pipe, and the outlet direction of the elbow is arranged tangent to the concentric circle.

9. A heavy oil slurry bed hydrocracking unit according to claim 7, characterized in that: The inner diameter range of the circulating oil distribution pipe is 15 to 32 mm.

10. A heavy oil slurry bed hydrocracking unit according to claim 1, characterized in that: Set up one slurry bed reactor, or connect multiple slurry bed reactors in series.

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