CN112342059A

CN112342059A - Method for blending catalytic cracking slurry oil in delayed coking unit

Info

Publication number: CN112342059A
Application number: CN201910721420.1A
Authority: CN
Inventors: 邵志才; 邓中活; 施瑢; 戴立顺; 刘涛; 聂鑫鹏; 任亮; 杨清河; 胡大为; 孙淑玲; 韩伟
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-08-06
Filing date: 2019-08-06
Publication date: 2021-02-09
Anticipated expiration: 2039-08-06
Also published as: CN112342059B

Abstract

The invention relates to a method for blending catalytic cracking slurry oil in a delayed coking device, which comprises the steps that the catalytic cracking slurry oil enters a hydrotreating unit and contacts with a catalyst in a hydrogenation reaction zone to react, the reaction effluent enters a gas-liquid separation zone to be separated to obtain hydrogen-rich gas and liquid-phase material flow, the liquid-phase material flow enters the delayed coking device to be blended, and the reaction effluent is separated to obtain dry coking gas, liquefied gas, coking gasoline, coking diesel oil, coking wax oil and coke. The invention prolongs the operation period of the hydrotreating unit for treating the catalytic cracking slurry oil, improves the light oil yield of the delayed coking device, and can produce petroleum coke with qualified sulfur content.

Description

Method for blending catalytic cracking slurry oil in delayed coking unit

Technical Field

The invention relates to a method for blending catalytic cracking slurry oil in a delayed coking device.

Background

Oil products containing solid particles such as catalytic cracking recycle oil and catalytic cracking slurry oil are low value-added products of catalytic cracking, have relatively high sulfur content and high content of polycyclic aromatic hydrocarbon and colloid, are difficult to crack in the catalytic cracking self-recycling process, and are easy to coke. Therefore, a part of oil slurry needs to be thrown outwards by the catalytic cracking device, and the content of solid particles in the oil slurry is higher (more than 2 g/L). In the prior art, solid particles in the catalytic cracking slurry oil are removed, and then the catalytic cracking slurry oil with the removed solid particles is treated and utilized again.

The existing methods for removing solid particles from catalytic cracking slurry oil mainly comprise the following steps, which respectively have the advantages and the disadvantages:

1. a natural sedimentation method: its advantages are simple equipment and easy operation. The disadvantages are long separation time, high investment cost, difficult removal of catalyst particles with the particle size less than 50um and poor purification effect.

2. And (3) a filtration method: the method has the advantages of simple operation and high short-term separation efficiency. The disadvantages are large filtration resistance, long washing time, difficult removal of micron-sized particles, easy damage of the filter element and difficult regeneration.

3. An electrostatic separation method: the advantages are easy washing, easy adsorption when the particles are finer, and low resistance. The disadvantages are complex flow, large equipment investment and low separation efficiency.

4. Centrifugal separation method: its advantages are simple structure and small size. The disadvantages are low separation efficiency, inconvenient operation and difficult maintenance.

5. An auxiliary agent sedimentation method: the advantages are simple equipment and convenient operation. The disadvantage is that the separation effect is not stable.

At present, no method for efficiently purifying the oil slurry exists, and the content of solid particles in the oil slurry after solid impurities are removed in the prior art is still high (higher than 300 ppm).

CN104119952B provides a hydrotreating method for hydrocarbon oil, in which hydrocarbon oil and hydrogen gas are contacted with a plurality of hydrogenation catalyst beds arranged in a hydrotreating device; the main hydrogenation pretreatment reactor and the standby hydrogenation pretreatment reactor can be alternately used. However, solid particles in the slurry tend to settle in the reactor bed, resulting in an increase in pressure drop.

CN103013567B A method for producing needle coke from catalytic slurry oil, the method is provided with a protection zone and a hydrogenation reaction zone, the catalytic cracking slurry oil firstly enters the protection zone, absorbs most of catalytic cracking catalyst powder, then is mixed with hydrogen gas and enters a heating furnace, and after heating, the catalytic cracking slurry oil enters the hydrogenation reaction zone for hydrogenation reaction. Solid particles in the oil slurry are easy to deposit in a protection zone or a hydrogenation reaction zone at the later stage of the operation period, so that the pressure drop is increased, and the long-period operation of the device is influenced.

CN1262306A discloses a combined process of hydrotreatment and catalytic cracking of residuum. The method comprises the steps of feeding the residue oil and clarified oil into a residue oil hydrogenation device, and carrying out hydrogenation reaction in the presence of hydrogen and a hydrogenation catalyst; the hydrogenated residual oil obtained by the reaction enters a catalytic cracking device, and a cracking reaction is carried out in the presence of a catalytic cracking catalyst; and separating the oil slurry obtained by the reaction by a separator to obtain clarified oil, and returning the clarified oil to the residual oil hydrogenation device. The method can convert catalytic cracking slurry oil into light oil with higher added value, and improve the yield of gasoline and diesel oil. Although the oil slurry is clarified in the method to obtain the solid particle content meeting the requirements of the residual oil hydrogenation raw material, the clarification time is longer and the clarification is difficult, and the solid content of the residual oil slurry is higher and the treatment is more difficult.

In the prior art, catalytic cracking slurry oil is directly sent to a delayed coking unit for blending, but due to the poor property of the catalytic cracking slurry oil, the quantity of light oil products added in the delayed coking unit product is limited. In addition, the sulfur content of the catalytic cracking slurry is high, resulting in a high sulfur content of the coke product from the delayed coker. The national energy agency released a new petroleum coke (green coke) standard (standard No. NB/SH/T0527-2015) at 2015, 10, 27, where the petroleum coke was classified under a sulfur content of 3 wt% or less. Thus, according to this standard, petroleum coke with a sulfur content of greater than 3 wt.% is considered a reject.

Disclosure of Invention

The invention aims to solve the technical problem that catalytic cracking slurry oil is difficult to treat in the prior art, and provides a method for blending catalytic cracking slurry oil in a delayed coking device.

The invention provides a method for blending catalytic cracking slurry oil by a delayed coking device, which comprises the following steps: the catalytic cracking slurry oil enters a hydrotreating unit, the hydrotreating unit is provided with a hydrogenation reaction zone and a gas-liquid separation zone, the hydrogenation reaction zone is sequentially filled with a hydrogenation protective agent, a hydrodemetallization agent and/or a hydrodesulphurization agent along the material flow direction, the particle size of a catalyst filled in the hydrodemetallization agent or the hydrodesulphurization agent along the end part of the material flow direction is not less than 1.6mm, the catalytic cracking slurry oil contacts with the catalyst in the hydrogenation reaction zone in the presence of hydrogen to react, the reaction effluent enters the gas-liquid separation zone to be separated to obtain hydrogen-rich gas and liquid-phase material flow, the liquid-phase material flow and a delayed coking raw material enter a delayed coking device to react, and the reaction effluent is separated to obtain dry coking gas, liquefied gas, coker gasoline, diesel oil, coker gas and coke.

In a preferred embodiment of the invention, a hydrogenation protective agent, a hydrogenation demetallizing agent or a hydrogenation desulfurizing agent are sequentially filled in the hydrogenation reaction zone along the material flow direction, the filling volume fraction of the hydrogenation protective agent is 20-95% and the filling volume fraction of the hydrogenation demetallizing agent or the hydrogenation desulfurizing agent is 5-80% based on the hydrogenation reaction zone integral catalyst, wherein the filling volume fraction of the hydrogenation demetallizing agent or the hydrogenation desulfurizing agent with the particle size not less than 1.6mm is 5-70%.

In a preferred embodiment of the invention, a hydrogenation protective agent, a hydrogenation demetallizing agent and a hydrogenation desulfurizing agent are sequentially filled in a hydrogenation reaction zone along a material flow direction, based on a hydrogenation reaction zone integral catalyst, the filling volume fraction of the hydrogenation protective agent is 20-70%, the filling volume fraction of the hydrogenation demetallizing agent is 10-60%, and the filling volume fraction of the hydrogenation desulfurizing agent is 10-60%, wherein the filling volume fraction of the hydrogenation desulfurizing agent with the particle size not less than 1.6mm is 10-60%.

The specification of the catalyst is mainly determined by the particle size and length of the catalyst, and generally, the specification of the length of the catalyst is fixed, and the specification of the catalyst is determined by the particle size of the catalyst. The particle diameter in the present invention means the maximum value of the distance between any two points on the cross section of the catalyst.

In a preferred case, the hydrogenation protection catalyst, the hydrodemetallization agent and the hydrodesulfurization agent are each packed with one or more species. In the invention, the grading condition of the hydrogenation protective agent, the hydrogenation demetallizing agent and/or the hydrogenation desulfurizing agent can be optimized according to the conditions of the pore structure, the activity, the material property, the operation condition and the like of the catalyst. When one preferred embodiment of the present invention is adopted, the hydrogenation reaction zone is sequentially filled with the hydrogenation protective agent and the hydrodemetallization agent along the material flow direction, and the hydrogenation protective agent and the hydrodemetallization agent can be respectively filled with one or more of the hydrogenation protective agent and the hydrodemetallization agent, wherein the particle size of the hydrodemetallization agent filled at the end part along the material flow direction is not less than 1.6 mm.

When one preferred embodiment of the present invention is adopted, the hydrogenation reaction zone is sequentially filled with the hydrogenation protective agent and the hydrodesulfurization agent along the material flow direction, and the hydrogenation protective agent and the hydrodesulfurization agent can be respectively filled with one or more of the hydrogenation protective agent and the hydrogenation desulfurization agent, wherein the particle size of the hydrodesulfurization agent filled at the end part along the material flow direction is not less than 1.6 mm.

When one preferred embodiment of the invention is adopted, the hydrogenation reaction zone is sequentially filled with the hydrogenation protective agent, the hydrogenation demetallizing agent and the hydrogenation desulfurizing agent along the material flow direction, the hydrogenation protective agent, the hydrogenation demetallizing agent and the hydrogenation desulfurizing agent can be respectively filled with one or more of the hydrogenation protective agent, the hydrogenation demetallizing agent and the hydrogenation desulfurizing agent, wherein the particle size of the hydrogenation desulfurizing agent filled at the tail end part along the material flow direction is not less than 1.6 mm.

In the invention, the hydrogenation protective agent, the hydrogenation demetallization agent and the hydrogenation desulfurization agent can adopt hydrogenation protective agent, hydrogenation demetallization agent and hydrogenation desulfurization agent which are commonly used in the field. For example, the active components of the hydrogenation protective agent, the hydrodemetallization agent and the hydrodesulfurization agent can be non-noble metals selected from group VIB and/or group VIII, preferably nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or a combination of cobalt-molybdenum; the carrier is one or more selected from alumina, silica or titanium oxide. The carrier can be modified by adding elements such as phosphorus, boron or fluorine. The catalyst is in the form of extrudate or sphere, with a diameter of 0.5-50.0mm and a bulk density of 0.3-1.2g/cm³The specific surface area is 50-300m²(ii) in terms of/g. For example, the hydrogenation protective agent, the hydrogenation demetallization agent and the hydrogenation desulfurization agent can respectively adopt RG series, RUF series, RDM series and RMS series commercial catalysts developed by China petrochemical engineering science research institute.

In a preferable case, the hydrogenation protective agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of alumina, silica and titanium oxide, the active component is selected from at least one VIB group metal and/or at least one VIII group metal, the active component accounts for 0-15 wt% of the hydrogenation protective agent in terms of oxide based on the weight of the hydrogenation protective agent, and the balance is the carrier; the average pore diameter of the hydrogenation protective agent is 18-30nm, and the particle size is 1.6-50 mm.

In a preferable case, the hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, the active component is selected from at least one VIB group metal and/or at least one VIII group metal, the active component accounts for 3-25 wt% of the hydrodemetallization agent calculated by oxide based on the weight of the hydrodemetallization agent, and the balance is the carrier; the average pore diameter of the hydrodemetallization agent is 10-30nm, and the particle size is 1.6-5 mm.

In a preferable case, the hydrodesulfurization agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, the active component is selected from at least one VIB group metal and/or at least one VIII group metal, the active component accounts for 5-35 wt% of the weight of the hydrodesulfurization agent, calculated by oxides, and the balance is the carrier; the average pore diameter of the hydrodesulfurization agent is 7-15nm, and the particle size is 1.6-5 mm.

In a preferred aspect, the reaction conditions in the hydrogenation reaction zone are: the reaction pressure is 1.0-20MPa, the reaction temperature is 100-400 ℃, and the liquid hourly space velocity is 0.10-10.0h^-1The volume ratio of hydrogen to oil is 10-1000. Further preferably, the reaction conditions of the hydrogenation reaction zone are as follows: the reaction pressure is 2.0-16MPa, the reaction temperature is 200-^-1The volume ratio of hydrogen to oil is 50-500.

In a preferred aspect, the hydrogen content of the hydrogen-containing gas entering the hydrogenation reaction zone is from 20% to 100% by volume. Further preferably, the hydrogen-containing gas entering the hydrogenation reaction zone is one or more selected from catalytic cracking dry gas, coking dry gas, hydrogenation unit low-temperature gas and hydrogen.

The separation conditions of the gas-liquid separation zone are well known to those skilled in the art, and the separation pressure in the gas-liquid separation zone is the system pressure, i.e. the pressure of the separation zone is the same as the pressure of the hydrogenation reaction zone.

The flow direction of the catalytic cracking slurry oil in the hydrogenation reaction zone is not particularly limited, and each reactor arranged in the hydrogenation reaction zone can be a downflow reactor, an upflow reactor or a counter-flow reactor. The downflow reactor refers to a reactor with a material flow flowing from top to bottom; the upflow reactor refers to a reactor with material flow flowing from bottom to top; the counter-flow reactor refers to a reactor with liquid and gas flowing in opposite directions.

The number of reactors provided in the hydrogenation reaction zone of the present invention is not particularly limited.

In the present invention, the catalytic cracking slurry oil is obtained from a catalytic cracking unit which is conventional in the art, and the specific catalytic cracking unit is not limited at all. Preferably, the initial boiling point temperature of the catalytic cracking slurry oil is 410-450 ℃. The catalytic cracking slurry oil is subjected to hydrotreating in a hydrotreating unit, most of sulfur compounds in the catalytic cracking slurry oil are removed, aromatic hydrocarbons are partially saturated, and asphaltene and colloid are also subjected to hydroconversion at the same time, so that a better raw material is provided for a delayed coking device. Meanwhile, the optimized catalyst grading mode reduces the deposition speed of solid particles in the hydrogenation reaction zone and effectively prolongs the operation period of the hydrogenation reaction zone.

The delayed coker of the present invention is a delayed coker as is conventional in the art. The delayed coking raw oil, the circulating oil and the liquid phase material flow obtained by the hydrotreating unit are heated by a heating furnace together to be rapidly heated to the coking reaction temperature, and enter a coke tower for coking reaction, and the mode of continuous feeding of the heating furnace and alternate operation of the coke tower is adopted. And the obtained oil gas product enters a fractionating tower, and is fractionated to obtain coking dry gas, liquefied gas, coking gasoline, coking diesel oil, coking wax oil and unconverted oil. The coker gas oil can be sent to a catalytic cracking unit and a hydrocracking unit for further processing. The resulting unconverted oil is recycled back to the feed oil system of the delayed coker as cycle oil. After the coke in the coke tower is filled up, the hot raw material is improved into another coke tower, and the residual coke in the coke tower is discharged by hydraulic decoking. The coke drum is returned to empty and then the hot feed is introduced. The obtained coke is petroleum coke, is one of important products in the delayed coking process, and can be used as electrodes, metallurgy, fuels and the like according to different qualities. By the method, petroleum coke with the sulfur content of less than 3 weight percent can be produced when the catalytic cracking slurry oil is blended in the delayed coking device, and the new standard requirement of the national energy agency is met.

In the present invention, the preferred process conditions of the delayed coking unit are: the outlet temperature of the heating furnace is 470-570 ℃, the top pressure of the coke tower is 0.01-0.30MPa, and the flow ratio of the circulating oil at the bottom of the fractionating tower to the fresh raw material is 0-0.5.

In the present invention, the delayed coking feedstock is a conventional delayed coking feedstock, preferably a vacuum residuum having a boiling point >350 ℃.

Compared with the prior art, the invention has the advantages that:

(1) according to the invention, the large-particle hydrodemetallization agent or hydrodesulfurization agent is introduced into the rear part of the hydrogenation reaction zone along the material flow direction, so that the speed of depositing solid particles in the catalytic cracking slurry oil on the reaction bed layer is obviously slowed down, and the long-period operation of the hydrotreating unit is ensured.

(2) In the invention, the catalytic cracking slurry oil is subjected to heteroatom removal and hydrogenation saturation in the hydrogenation treatment unit, the saturation and hydrogen content are increased, the property of the catalytic cracking slurry oil is improved, the catalytic cracking slurry oil is used as a raw material of a delayed coking device, the light oil yield of the delayed coking device is effectively improved, and the petroleum coke with qualified sulfur content can be produced.

Drawings

FIG. 1 is a schematic flow diagram of a process for blending catalytic cracking slurry oil in a delayed coking unit.

FIG. 2 is a schematic flow diagram of a hydrotreating unit in a delayed coker blending catalytic cracking slurry oil process provided by the invention.

Detailed Description

The method for blending catalytic cracking slurry oil by the delayed coking unit provided by the invention is further explained by combining the attached drawings.

FIG. 1 is a schematic flow diagram of the method for blending catalytic cracking slurry oil in the delayed coking unit. As shown in figure 1, catalytic cracking slurry oil 11 and refinery gas 12 enter a hydrotreating unit 1, a hydrogenation protective agent, a hydrodemetallization agent and/or a hydrodesulfurization agent are sequentially filled in a hydrogenation reaction zone of the hydrotreating unit along the material flow direction, the particle size of the catalyst filled in the end part of the hydrodemetallization agent or the hydrodesulfurization agent along the material flow direction is not less than 1.6mm, the catalytic cracking slurry oil contacts the catalyst in the hydrogenation reaction zone in the presence of hydrogen to react, the reaction effluent is separated to obtain hydrogen-rich gas and liquid phase material flow, the liquid phase material flow 2 and the delayed coking raw material 13 enter a delayed coking device 3 together for reaction, the reaction effluent is separated to obtain coked dry gas 4, liquefied gas 5, coked gasoline 6, coked diesel oil 7, coked wax oil 8 and unconverted oil 9, and the unconverted oil 9 is returned to the inlet of the delayed coking cracking device as circulating oil.

FIG. 2 is a schematic flow diagram of a hydrotreating unit in the process of blending catalytic cracking slurry oil in the delayed coking unit provided by the invention. As shown in fig. 2, the hydrotreating unit includes a hydrogenation reaction zone 1 and a gas-liquid separation zone 3, the catalytically cracked slurry oil 6 and the refinery gas 7 are mixed and then enter the hydrogenation reaction zone 1 in a downflow feeding manner, and contact-react with a hydrogenation catalyst bed under the hydrogenation reaction condition, and the reaction effluent 2 enters the gas-liquid separation zone 3 for separation, so as to obtain a hydrogen-rich gas 4 and a liquid phase material flow 5.

The following examples are provided to further illustrate the specific features and effects of the present invention, but are not intended to limit the present invention.

The hydrogenation catalysts used in the examples and comparative examples were all the catalysts of the residue oil hydrotreating series developed by the institute of petrochemical engineering science and technology in China and produced by Changjingtong division of petrochemical catalysts, and the compositions of the catalysts used in the examples and comparative examples are shown in Table 1, and the grading state ratios are shown in Table 2, wherein RG series is a hydrogenation protecting agent, RDM series is a hydrodemetalizing agent, and RMS series is a hydrodesulfurization agent. The suffix of each catalyst name indicates the particle size of the catalyst, e.g., RG-30B-3.0 represents a particle size of 3.0mm for the hydrogenation protecting agent, RDM-35-1.6 represents a particle size of 1.6mm for the hydrodemetallization agent, and RMS-3-1.6 represents a particle size of 1.6mm for the hydrodesulfurization agent.

Examples 1-4 the hydrogen-containing gas employed in the hydroprocessing unit was refinery gas, which consisted of hydrogen, methane, ethane and propane. Examples 5-6, comparative examples 1-2 the hydrogen-containing gas employed in the hydroprocessing unit was hydrogen.

Examples 1 to 4

The catalytic cracking slurry oil and the hydrogen-containing gas enter a hydrogenation reaction zone of a hydrotreating unit together, a fixed bed reactor is arranged in the hydrogenation reaction zone, the catalytic cracking slurry oil contacts with a catalyst in the fixed bed reactor in the presence of hydrogen to react, and the reaction effluent enters a gas-liquid separation zone to be separated, so that hydrogen-rich gas and liquid-phase material flow are obtained. The catalyst loading grading scheme for the hydrogenation reaction zone is shown in table 2, the hydrogenation process conditions are shown in table 3, and the catalytic cracking slurry oil and liquid stream properties are shown in table 4. As can be seen from Table 4, the properties of the catalytically cracked slurry oil are significantly improved by removing most of the sulfur and increasing the hydrogen content properly in the hydrogenation reaction zone.

Example 5

The catalytic cracking slurry oil and the hydrogen-containing gas enter a hydrogenation reaction zone of a hydrotreating unit, and two fixed bed reactors connected in series are arranged in the hydrogenation reaction zone. In the presence of hydrogen, the catalytic cracking slurry oil is sequentially contacted with catalysts in two fixed bed reactors for reaction, and the reaction effluent enters a gas-liquid separation zone for separation to obtain hydrogen-rich gas and liquid phase material flow. The catalyst loading grading scheme for the hydrogenation reaction zone is shown in table 2, the hydrogenation process conditions are shown in table 3, and the properties of the catalytically cracked slurry oil and liquid streams are shown in table 5. In this example, a 6000-hour stability test was performed, wherein the pressure drop R-1 was 0.10MPa and the pressure drop R-2 was 0.12MPa when the hydrotreater started to operate, and the pressure drop R-1 was increased to 0.11MPa and the pressure drop R-2 was 0.12MPa after the hydrotreater operated for 6000 hours.

Comparative example 1

The comparative example uses the same raw materials, process conditions and process flow as example 5, except that the catalyst grading scheme was different. The catalyst loading grading scheme for the hydrogenation reaction zone is shown in table 2, the hydrogenation process conditions are shown in table 3, and the properties of the catalytically cracked slurry oil and liquid streams are shown in table 5. The comparative example was subjected to a 6000-hour stability test, wherein the pressure drop R-1 was 0.09MPa and the pressure drop R-2 was 0.12MPa when the hydrotreater started to operate, and the pressure drop R-1 was increased to 0.30MPa and the pressure drop R-2 was increased to 0.75MPa when the hydrotreater operated for 6000 hours.

Example 6

The catalytic cracking slurry oil and the hydrogen-containing gas enter a hydrogenation reaction zone of a hydrotreating unit, and two fixed bed reactors connected in series are arranged in the hydrogenation reaction zone. In the presence of hydrogen, the catalytic cracking slurry oil is sequentially contacted with catalysts in two fixed bed reactors for reaction, and the reaction effluent enters a gas-liquid separation zone for separation to obtain hydrogen-rich gas and liquid phase material flow. The catalyst loading grading scheme for the hydrogenation reaction zone is shown in table 2, the hydrogenation process conditions are shown in table 3, and the properties of the catalytically cracked slurry oil and liquid streams are shown in table 5. In this example, a 6000-hour stability test was performed, wherein the pressure drop R-1 was 0.09MPa and the pressure drop R-2 was 0.12MPa at the beginning of the operation of the apparatus, and after the operation of the apparatus was 6000 hours, the pressure drop R-1 was increased to 0.10MPa and the pressure drop R-2 was 0.13 MPa.

Comparative example 2

The comparative example used the same starting materials, process conditions and process flow as in example 6, except that the catalyst staging scheme was different. The catalyst loading grading scheme is shown in table 2, the hydroprocessing conditions are shown in table 3, and the catalytic cracking slurry and liquid stream properties are shown in table 5. The comparative example was subjected to a 6000h stability test, wherein the pressure drop R-1 was 0.10MPa and the pressure drop R-2 was 0.13MPa at the start of the operation of the apparatus, and after the operation of the apparatus was 6000h, the pressure drop R-1 was increased to 0.35MPa and the pressure drop R-2 was increased to 0.69 MPa.

As can be seen from the comparison between examples 5-6 and comparative examples 1-2, the method of the present invention introduces the large-particle hydrodemetallization agent or hydrodesulfurization agent at the rear part of the hydrogenation reaction zone along the material flow direction, so that the solid particles in the catalytic cracking slurry oil can be prevented from depositing in the reaction bed layer as much as possible, or the deposition speed is significantly slowed down, but the quality of the catalytic cracking slurry oil is improved, the long-period operation of the hydrotreating unit is ensured, a raw material with better properties is provided for the subsequent delayed coking unit, and the economical efficiency of the delayed coking unit operation is improved.

Example 7

The liquid stream obtained in example 6 was used to feed a delayed coking unit together with a delayed coking feedstock having the properties shown in table 6 and the delayed coking test conditions were: the reaction temperature is 498 ℃, the pressure at the top of the coke tower is 0.15MPa, and the circulation ratio is 0.25. The delayed coker product yields are shown in table 7. The sulfur content of the resulting petroleum coke was 2.8 wt.%.

Comparative example 3

The same delayed coking feedstock as in example 7 was fed to a delayed coking unit, and the catalytically cracked slurry oil was fed directly to the delayed coking unit without passing through a hydrotreating unit under the following delayed coking test conditions: the reaction temperature is 498 ℃, the pressure at the top of the coke tower is 0.15MPa, and the circulation ratio is 0.25. The delayed coker product yields are shown in table 7. The sulfur content of the resulting petroleum coke was 3.2 wt.%.

As can be seen from table 7 by comparing the product yields of example 7 and comparative example 3, in example 7, the quality of the catalytically cracked slurry oil is improved by hydrogenating the catalytically cracked slurry oil by the method of the present invention, a raw material with better properties is provided for the delayed coking unit, the yield of light oil of the delayed coking unit is increased, the sulfur content of coke is reduced, a petroleum coke product with qualified sulfur content is obtained, and the economy of the delayed coking unit operation is significantly improved.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

Item	Delayed coking feedstock
		Density (20 ℃ C.)/(kg/m)³)	102.85
Viscosity (100 ℃ C.)/(mm)²/s)	1800
		Carbon residue value/weight%	20.60
Sulfur content/weight%	2.65
		Nitrogen content/weight%	0.40
Hydrogen content/weight%	10.72
		Metal (Ni + V) content/(μ g/g)	202.2

TABLE 7

	Example 7	Comparative example 3
			Distribution of the product, weight%
Dry gas of coking	4.85	4.95
			Liquefied gas	3.12	3.33
Coking gasoline	15.9	15.86
			Coking diesel oil	32.31	30.53
Coker gas oil	20.02	19.43
			Coke	23.8	25.90
Total up to	100.00	100.00
			Total liquid yield, weight%	51.33	49.72

Claims

1. A process for blending catalytic cracking slurry oil with delayed coking unit includes such steps as loading the catalytic cracking slurry oil into a hydrogenation unit, arranging a hydrogenation reaction region and a gas-liquid separation region in the hydrogenation unit, the hydrogenation reaction zone is sequentially filled with a hydrogenation protective agent, a hydrogenation demetallization agent and/or a hydrogenation desulfurizing agent along the material flow direction, the particle size of the catalyst filled in the end part of the hydrodemetallization agent or the hydrodesulfurization agent along the material flow direction is not less than 1.6mm, the catalytic cracking slurry oil contacts the catalyst in the hydrogenation reaction zone in the presence of hydrogen to react, the reaction effluent enters a gas-liquid separation zone for separation to obtain hydrogen-rich gas and liquid phase material flow, the liquid phase material flow and the delayed coking raw material enter a delayed coking device together for reaction, the reaction effluent is separated to obtain dry coking gas, liquefied gas, coking gasoline, coking diesel oil, coking wax oil and coke.

2. The method according to claim 1, wherein the hydrogenation reaction zone is sequentially filled with the hydrogenation protective agent, the hydrogenation demetallizing agent or the hydrogenation desulfurizing agent along the material flow direction, the filling volume fraction of the hydrogenation protective agent is 20-95% and the filling volume fraction of the hydrogenation demetallizing agent or the hydrogenation desulfurizing agent is 5-80% based on the hydrogenation reaction zone whole catalyst, wherein the filling volume fraction of the hydrogenation demetallizing agent or the hydrogenation desulfurizing agent with the particle size not less than 1.6mm is 5-70%.

3. The method according to claim 1, wherein the hydrogenation reaction zone is sequentially filled with the hydrogenation protective agent, the hydrodemetallization agent and the hydrodesulfurization agent along the material flow direction, the filling volume fraction of the hydrogenation protective agent is 20-70%, the filling volume fraction of the hydrodemetallization agent is 10-60%, and the filling volume fraction of the hydrodesulfurization agent is 10-60% based on the hydrogenation reaction zone integral catalyst, wherein the filling volume fraction of the hydrodesulfurization agent with the particle size of not less than 1.6mm is 10-60%.

4. The process of any of claims 1-3, wherein one or more of the hydrogenation protection catalyst, the hydrodemetallization agent, and the hydrodesulfurization agent are each loaded.

5. The method according to claim 4, characterized in that the hydrogenation protective agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is selected from one or more of alumina, silica and titania, the active component is selected from at least one group VIB metal and/or at least one group VIII metal, the active component accounts for 0-15 wt% of the oxide based on the weight of the hydrogenation protective agent, and the balance is the carrier; the average pore diameter of the hydrogenation protective agent is 18-30nm, and the particle size is 1.6-50 mm.

6. The method according to claim 4, wherein the hydrodemetallization agent comprises a carrier and an active component loaded on the carrier, the carrier is selected from one or more of alumina, silica and titania, the active component is selected from at least one group VIB metal and/or at least one group VIII metal, and the active component accounts for 3-25 wt% of the oxide and the balance is the carrier based on the weight of the hydrodemetallization agent; the average pore diameter of the hydrodemetallization agent is 10-30nm, and the particle size is 1.6-5 mm.

7. The method according to claim 4, wherein the hydrodesulfurization agent comprises a carrier and an active component loaded on the carrier, wherein the carrier is one or more selected from aluminum oxide, silicon oxide and titanium oxide, the active component is selected from at least one VIB group metal and/or at least one VIII group metal, and the active component accounts for 5-35 wt% of the weight of the hydrodesulfurization agent and the balance is the carrier in terms of oxides; the average pore diameter of the hydrodesulfurization agent is 7-15nm, and the particle size is 1.6-5 mm.

8. The method of claim 1, wherein the hydrogenation reaction zone is operated under the following reaction conditions: the reaction pressure is 1.0-20MPa, the reaction temperature is 100-400 ℃, and the liquid hourly space velocity is 0.10-10.0h^-1The volume ratio of hydrogen to oil is 10-1000.

9. The method of claim 1, wherein the hydrogenation reaction zone is operated under the following reaction conditions: the reaction pressure is 2.0-16MPa, the reaction temperature is 200-^-1The volume ratio of hydrogen to oil is 50-500.

10. The process of claim 1 wherein the hydrogen-containing gas entering the hydrogenation reaction zone has a hydrogen content of from 20% to 100% by volume.

11. The method of claim 10, wherein the hydrogen-containing gas entering the hydrogenation reaction zone is selected from one or more of catalytic cracking dry gas, coking dry gas, hydrogenation unit low-molecular gas and hydrogen.

12. The process of claim 1, wherein the process conditions of the delayed coker are: the outlet temperature of the heating furnace is 470-570 ℃, the top pressure of the coke tower is 0.01-0.30MPa, and the flow ratio of the circulating oil at the bottom of the fractionating tower to the fresh raw material is 0-0.5.