A kind of residual oil processing method

Abstract

The present invention discloses a residual oil processing method, which comprises the following steps: (1) obtaining atmospheric residual oil by atmospheric distillation of crude oil; (2) performing a hydrogenation treatment reaction on the atmospheric residual oil obtained in step (1); (3) separating the materials after the hydrogenation treatment reaction in step (2) to obtain a gas phase product, hydrogenated light oil, and hydrogenated heavy oil; (4) contacting the hydrogenated light oil obtained in step (3) with a hydrorefining catalyst for reaction; (5) contacting the reaction stream obtained in step (4) with a hydrocracking catalyst for reaction, and separating the reaction stream to obtain a gas phase, light naphtha, heavy naphtha, jet fuel, diesel, and tail oil. The method can efficiently process residual oil raw materials.

Description

Technical Field

[0001] This invention relates to a method for processing residual oil, and more specifically to a highly efficient method for combined processing of residual oil. Background Technology

[0002] With the increasing heavy and low-quality nature of petroleum resources and the continuous improvement of standards for cleaner petroleum fuels, higher demands are being placed on refining technologies. Hydrocracking technology integrates the processes of lightening and cleaning petroleum products. Its strong feedstock adaptability, high conversion depth, and good product quality, coupled with its efficient and flexible operation, have attracted widespread attention from the domestic and international refining and petrochemical industries. In my country, the composition of processed crude oil is predominantly heavy crude oil, with a low yield of vacuum gas oil fractions. This significantly limits the feedstock sources for hydrocracking. Expanding the feedstock sources for hydrocracking units is currently a key focus of research in hydrocracking technology.

[0003] CN02133138.3 discloses a method for heavy hydrocarbon hydrotreating, in which residual oil feedstock sequentially passes through a protective agent bed, a hydrodemetallization catalyst bed, a hydrodesulfurization catalyst bed, and a hydrodenitrogenation (cracking) catalyst bed, and deasphalted oil and / or coking wax oil are introduced after the protective agent bed and before the hydrodesulfurization catalyst bed. Compared with the prior art, the method of the present invention effectively utilizes the activity of highly active catalysts such as hydrodesulfurization, hydrodenitrogenation, and / or hydrocracking, so as to achieve balanced deactivation of various functional catalysts in the residual oil hydrotreating unit, reduce the operating cost of the hydrotreating catalyst, and treat the deasphalted oil and coking wax oil, enabling them to undergo downstream catalytic cracking or hydrocracking for lighter processing, reducing the need for rework of the hydrotreating unit. The method of the present invention is mainly used for the co-hydrotreating of residual oil and deasphalted oil and coking wax oil.

[0004] CN201910971938.0 discloses a combined hydrocracking and catalytic cracking process and apparatus. The combined hydrocracking and catalytic cracking process includes the following steps: a) after hydrocracking of the residue feedstock, heavy oil is collected and subjected to catalytic cracking to collect diesel or gasoline fractions; b) the diesel or gasoline fractions are subjected to further catalytic cracking to collect the product; the diesel fraction undergoes hydrorefining pretreatment before further catalytic cracking; wherein the initial boiling point of the heavy oil is 160–350°C. The apparatus includes a hydrocracking reactor, a catalytic cracking reactor, and a fractionation unit; the hydrocracking reactor is connected to the catalytic cracking reactor, and the catalytic cracking reactor is connected to the fractionation unit. This invention can optimize the combined hydrocracking and catalytic cracking process according to market changes, flexibly producing high-value-added liquefied petroleum gas or gasoline, and improving economic efficiency.

[0005] CN201310253090.0 discloses a combined hydrocracking-catalytic cracking method for processing coal tar and residual oil. The method involves: coal tar undergoing vacuum distillation to obtain light coal tar and heavy coal tar; the light coal tar and residual oil are mixed and subjected to hydrocracking; the hydrocracking effluent is separated into gaseous and liquid products; the liquid products are fractionated to obtain gasoline, diesel, vacuum gas oil, and tail oil; the tail oil obtained from hydrocracking is mixed with heavy coal tar and subjected to catalytic cracking under supercritical conditions to obtain cracked gas, light distillate oil, heavy distillate oil, and cracking residue oil. This method can improve feedstock conversion rate, reduce coking, increase light oil yield, slow down the deep condensation reaction of heavy feedstock oil in the catalytic cracking unit, and extend the life of the catalytic cracking catalyst, providing a more economical processing method for low-value-added residual oil and coal tar.

[0006] CN201310522928.1 discloses a method for hydroconversion of heavy oil, comprising hydrocracking, hydrocracking, and hydrotreating units: heavy oil first undergoes hydrocracking in a first reactor; the reaction products are separated into light distillate oil, heavy distillate oil, and residue oil; the residue oil, along with a hydrocracking catalyst and hydrogen, enters a second reactor for further hydrocracking; the heavy distillate oil and hydrogen enter a hydrocracking reactor, contacting with a hydrocracking catalyst and undergoing hydrocracking under hydrocracking conditions to obtain light oil; the light distillate oil and hydrogen enter a hydrorefining reactor, contacting with a hydrorefining catalyst and reacting to obtain hydrorefined light distillate oil; the reaction temperature of the second hydrocracking reactor is 5–50°C lower than that of the first reactor. Compared with the prior art, the method provided by this invention significantly improves the heavy oil conversion rate and light oil yield, while also obtaining high-performance gasoline and diesel products.

[0007] CN201610076818.0 discloses a method for processing heavy oil, which includes the following steps: (1) subjecting heavy oil to vacuum distillation to obtain vacuum wax oil and vacuum residue; (2) subjecting the vacuum residue to solvent-directed separation to obtain light deasphalted oil, heavy deasphalted oil, and deoiled asphalt; (3) subjecting the heavy deasphalted oil and the deoiled asphalt to delayed coking; (4) subjecting a portion of the vacuum wax oil and a portion of the light deasphalted oil to hydrocracking; and (5) subjecting the remaining vacuum wax oil, the remaining light deasphalted oil, the hydrocracking tail oil generated during the hydrocracking process, and the coking wax oil generated during the delayed coking process to catalytic cracking. The method provided by this invention can improve the yield and quality of light oil and increase the added value of the product.

[0008] CN201610003156.4 discloses a fluidized bed residue hydrocracking method. This method includes two fluidized bed reactors connected in series. The first fluidized bed reactor uses a residue hydrotreating catalyst, and the second fluidized bed reactor uses a residue hydrocracking catalyst. This method utilizes a rational catalyst gradation to achieve fluidized bed hydrocracking of residue feedstock under high conversion conditions, reducing sediment formation and ensuring stable long-term operation of the unit.

[0009] CN02133119.7 discloses a method for hydrocarbon hydroconversion, in which the feedstock is contacted with a catalyst having hydrodemetallization, hydrodesulfurization, hydronitrogenation, and / or hydrocracking functions. After hydrodemetallization and hydrodesulfurization, the feedstock is separated into light fractions, and the heavy fraction undergoes hydronitrogenation and / or hydrocracking reactions with fresh hydrogen and purified hydrogen-rich gas. Compared with existing technologies, this invention increases the hydrogen saturation of polycyclic aromatic hydrocarbons, improves the conversion rate of heavy feedstocks and the impurity removal rate, while reducing further deep cracking of low-boiling-point fractions and hydrogen consumption in the unit, and also reducing the load on downstream light-grade conversion units. This invention is most suitable for fixed-bed hydroconversion processes of heavy and residual oils.

[0010] CN201210244787.7 discloses a combined heavy oil processing technology that overcomes the shortcomings of existing technologies, such as resource waste and high energy consumption. It can increase the yield of diesel oil by 2-5% by weight and vacuum wax oil by 1-6% by weight. The heavy oil enters a flash separator for separation, and the separated <480℃ distillate oil enters a vacuum tower for vacuum distillation. The 200-350℃ distillate oil is used as diesel oil, and the 350-565℃ distillate oil is used as feedstock for catalytic cracking or hydrocracking. Part of the >565℃ vacuum residue oil is mixed with the >480℃ oil fraction and used as feedstock for a residue hydrotreating unit, while the other part of the >565℃ vacuum residue oil is used as feedstock for delayed coking.

[0011] In summary, in the existing technology, the residual oil feedstock is first separated into light components in the atmospheric distillation tower of the atmospheric and vacuum distillation unit. The bottom oil of the atmospheric distillation tower (i.e., atmospheric residue) enters the vacuum distillation tower for separation to obtain diesel, vacuum wax oil, and vacuum residue. When vacuum residue is used as feedstock for hydrocracking, its dry point generally does not exceed 560°C to prevent the entrainment of metals and asphaltenes from causing rapid deactivation of the hydrocracking catalyst. This also greatly limits the feedstock source for the hydrocracking unit. At the same time, the increased dry point of vacuum wax oil will also cause a significant increase in the nitrogen content in the feedstock, increasing the difficulty of denitrification in the hydrocracking pretreatment reaction zone, and the increase in ammonia partial pressure will inhibit the cracking activity of the hydrocracking catalyst. Summary of the Invention

[0012] To address the shortcomings of existing technologies, this invention provides a method for processing residual oil, which can efficiently process residual oil raw materials.

[0013] A method for processing residual oil, the method comprising the steps of:

[0014] (1) Crude oil is distilled at atmospheric pressure to obtain atmospheric residue oil;

[0015] (2) The atmospheric residue oil obtained in step (1) is subjected to hydrotreating reaction, and the nitrogen content in the liquid phase stream after hydrotreating reaction is controlled to be 1500mg / kg~3500mg / kg, preferably 2000mg / kg~3000mg / kg;

[0016] (3) After the material after the hydrogenation reaction in step (2) is separated, gaseous products, hydrogenated light oil and hydrogenated heavy oil are obtained. The cutting temperature of hydrogenated light oil and hydrogenated heavy oil is controlled at 500℃~800℃, preferably 550℃~750℃.

[0017] (4) The hydrotreated light oil obtained in step (3) reacts with the hydrorefining catalyst;

[0018] (5) The reaction stream obtained in step (4) is reacted with the hydrocracking catalyst. The reaction stream is separated to obtain gas phase, light naphtha, heavy naphtha, jet fuel, diesel and tail oil.

[0019] In the above method, the properties of the crude oil mentioned in step (1) are as follows: its density is generally 0.80 g / cm³. -3 ~1.10 g / cm -3 0.85g / cm -3 ~0.95g / cm -3 The nitrogen content is generally 0.1% to 0.6% (preferably 0.2% to 0.4%); the sulfur content is generally 1% to 6% (preferably 2% to 4%); and the metal content is generally 10 mg / kg to 100 mg / kg (preferably 20 mg / kg to 60 mg / kg).

[0020] In the above method, the atmospheric residue oil described in step (1) has the following properties: the distillation range is generally >300℃, preferably >350℃; the density is generally 0.95 g / cm³. -3 ~1.10 g / cm -3 Preferred concentration: 1.0 g / cm³ -3 ~1.05g / cm -3 The nitrogen content is generally 0.2m%~1.0m%, preferably 0.3m%~0.8m%; the sulfur content is generally 2m%~8m%, preferably 4m%~6m%; the metal content is generally 20mg / kg~200mg / kg, preferably 40mg / kg~100mg / kg.

[0021] In the above method, the atmospheric distillation conditions in step (1) are as follows: the pressure at the top of the column is 0.04MPa~0.12MPa, preferably 0.06MPa~0.10MPa; the feed temperature for atmospheric distillation is generally 330℃~390℃, preferably 350℃~370℃.

[0022] In the above method, in step (2), the atmospheric residue oil is sequentially contacted with the hydroprotecting agent, the hydrodemetallization catalyst and the hydrorefining catalyst to carry out the hydrotreating reaction.

[0023] The properties of the hydrogenation protective agent are as follows: It uses porous refractory inorganic oxides such as alumina as a support, and oxides of Group VIB and / or Group VIII metals such as W, Mo, Co, Ni, etc., as the active component, with a mass content of 1%–15% (based on oxides) in the catalyst, preferably 4%–10%. Group VIII metals are selected from nickel and / or cobalt, with a mass content of 1%–6% (based on oxides) in the catalyst, preferably 1.5%–4%. Other auxiliary agents such as P, Si, F, B, etc., are selectively added to the catalyst. The properties of the hydrogenation demetallization catalyst are as follows: It uses porous refractory inorganic oxides such as alumina as a support, and oxides of Group VIB and / or Group VIII metals such as W, Mo, Co, Ni, etc., as the active component, with a mass content of 1%–20% (based on oxides) in the catalyst. The content of the group VIB metal is preferably 10% to 15%, and the group VIII metal is selected from nickel and / or cobalt. The mass content of the group VIB metal in the catalyst is 1% to 6%, preferably 2% to 5%, based on the oxide content. Other catalysts such as P, Si, F, B, etc. are selectively added. The properties of the hydrorefining catalyst are as follows: the support is an inorganic refractory oxide, generally selected from one or more of alumina, amorphous aluminosilicate, silica, or titanium oxide. The active metal for hydrorefining includes group VIB and / or group VIII metal components. In the hydrorefining catalyst, the group VIB metal is selected from tungsten and / or molybdenum. The mass content of the group VIB metal in the catalyst is 10% to 30%, preferably 15% to 25%, based on the oxide content. The mass content of the group VIII metal is selected from nickel and / or cobalt. The mass content of the group VIII metal in the catalyst is 1% to 6%, preferably 3% to 5%, based on the oxide content.

[0024] In the above method, the operating conditions for the hydrogenation reaction in step (2) are as follows: reaction pressure 10.0–35.0 MPa, preferably 14.0–20.0 MPa; average reaction temperature 150–450 °C, preferably 360–400 °C; liquid hourly space velocity 0.1–15.0 h⁻¹. -1 Preferably 0.2–3.0 h -1 The hydrogen-to-oil volume ratio is 100:1 to 2500:1, preferably 600:1 to 1200:1.

[0025] In the above method, the material after hydrogenation treatment in step (3) is separated into gaseous and liquid products by a high-pressure separator. The high-pressure separator is controlled at a temperature of 200℃~350℃, preferably 230℃~300℃. The liquid product is separated into hydrogenated light oil and hydrogenated heavy oil by a fractionation tower.

[0026] In the above method, the properties of the hydrorefining catalyst in step (4) are as follows: the support is an inorganic refractory oxide, generally selected from one or more of alumina, amorphous silica-alumina, silica or titanium dioxide; the hydrorefining active metal includes group VIB and / or group VIII metal components, the group VIB in the hydrorefining catalyst is selected from tungsten and / or molybdenum, and the content in the catalyst by mass of oxide is 10% to 40%, preferably 20% to 30%, and the group VIII is selected from nickel and / or cobalt, and the content in the catalyst by mass of oxide is 1% to 6%, preferably 3% to 5%.

[0027] In the above method, the reaction conditions in step (4) are as follows: reaction pressure 10.0–35.0 MPa, preferably 14.0–20.0 MPa; average reaction temperature 150–450 °C, preferably 360–400 °C; liquid hourly space velocity 0.1–15.0 h⁻¹. -1 Preferably 0.2–3.0 h -1 The hydrogen-to-oil volume ratio is 100:1 to 2500:1, preferably 600:1 to 1500:1.

[0028] In the above method, the hydrocracking catalyst described in step (5) has the following properties: the cracking component is a Y-type composite molecular sieve. The binder is usually alumina or silica. The hydrogenation component is a group VI, VII, VIB or VIII metal, metal oxide or metal sulfide with VIB and / or VIII group metal as the active metal component, more preferably one or more of iron, chromium, molybdenum, tungsten, cobalt, nickel, or their sulfides or oxides. Based on the weight of the hydrocracking catalyst, the hydrogenation component content is usually 5-40 wt%, and the cracking component content is 10%-50 wt%, preferably 20%-40 wt%.

[0029] In the above method, the reaction conditions in step (5) are as follows: reaction pressure 10.0–35.0 MPa, preferably 14.0–10.0 MPa; average reaction temperature 150–450 °C, preferably 380–420 °C; liquid hourly space velocity 0.1–15.0 h⁻¹. -1 Preferably 0.2–3.0 h -1 The hydrogen-to-oil volume ratio is 100:1 to 2500:1, preferably 1000:1 to 1600:1.

[0030] Compared with the prior art, the present invention provides a method for processing residual oil, which has the following advantages:

[0031] (1) First, by hydrotreating atmospheric residue, the nitrogen content in the liquid stream after hydrotreating is controlled so that difficult-to-treat asphaltene and metal impurities are concentrated in the hydrotreated heavy oil. Then, by fractionating and controlling the appropriate cutting temperature of hydrotreated light oil and hydrotreated heavy oil, the dry point of hydrocracking feedstock can be greatly increased, the yield of hydrocracking feedstock can be increased, and the sulfur and nitrogen content in hydrocracking feedstock can be reduced, thereby improving the cracking performance of hydrocracking catalyst.

[0032] (2) Conventional residue hydrotreating feedstock is vacuum residue mixed with a certain proportion of low viscosity oil to improve the viscosity of residue feedstock. Using atmospheric residue directly as residue hydrotreating feedstock can effectively reduce the viscosity of residue hydrotreating feedstock, improve the hydrotreating reaction effect of residue hydrotreating unit, and extend the unit operation cycle.

[0033] (3) The residue hydrotreating and hydrocracking units achieve efficient coupling. The two units share a circulating hydrogen system and a desulfurization hydrogen system. At the same time, the atmospheric and vacuum distillation unit does not need to be equipped with a vacuum distillation tower, which greatly reduces the investment and operating costs of the unit. Attached Figure Description

[0034] Figure 1 This is a schematic diagram illustrating the principle flow of a residual oil processing method used in an embodiment of the present invention.

[0035] Atmospheric residue 1 is mixed with hydrogen 2 and enters the residue hydrotreating reactor 3. The residue hydrotreating effluent 4 enters the separator 5 and the separated gas phase 6 is recycled. The liquid phase 7 enters the fractionation tower 8 and the separated liquid phase 10 exits the unit. The gas phase 9 enters the hydrocracking pretreatment reactor 11. The pretreatment reaction effluent 12 enters the hydrocracking reactor 13. The hydrocracking reaction effluent 14 enters the separator 15 and the separated gas phase 16 is recycled. The liquid phase 17 enters the fractionation tower 18 and is separated to obtain gas 19, naphtha 20, jet fuel 21, diesel 22, and tail oil 23. Detailed Implementation

[0036] The following examples further illustrate the function and effect of the present invention, but the following examples do not constitute a limitation on the method of the present invention. Unless otherwise specified, all percentages in this application are mass percentages.

[0037] In this embodiment of the invention, the protective agent used in the residue hydrotreating reactor is FZC-103, the hydrodemetallizing agent is FZC-204, the hydrorefining catalyst is FZC-41BT, the hydrocracking pretreatment catalyst is FF-66, and the hydrocracking catalyst is FC-76. All catalysts are manufactured by Sinopec Catalyst Co., Ltd., and their physicochemical properties are shown in Table 1. The properties of the crude oil used in the examples and comparative examples are shown in Table 2, the properties of the atmospheric residue oil after atmospheric distillation are shown in Table 3, and the process conditions and experimental results of the examples are shown in Table 4.

[0038] Table 1

[0039]

[0040] Table 2

[0041]

[0042] Table 3

[0043]

[0044] Table 4

[0045]

[0046] As can be seen from the above examples, the method of the present invention can effectively broaden the distillation range of hydrocracking feedstock for atmospheric residue oil.

Claims

1. A residual oil processing method, characterized in that: The method comprises the steps of: (1) Atmospheric residue is obtained by atmospheric distillation of crude oil; (2) the atmospheric residue obtained in step (1) is subjected to a hydroprocessing reaction, and the nitrogen content in the liquid phase stream after the hydroprocessing reaction is controlled to be 1500 mg / kg to 3500 mg / kg; (3) After the material from the hydrotreatment reaction in step (2) is separated, a gas phase product, hydrogenated light oil, and hydrogenated heavy oil are obtained, and the cutting temperature of the hydrogenated light oil and the hydrogenated heavy oil is controlled to be 600° C. to 800° C.; (4) the hydrogenated light oil obtained in step (3) is contacted with a hydrotreating catalyst for reaction; (5) the reaction stream obtained in step (4) is contacted with a hydrocracking catalyst to react, and the post-reaction stream is separated to obtain a gas phase, light naphtha, heavy naphtha, jet fuel, diesel and tail oil; Step (3) The material after the hydrogenation reaction is separated into gas phase product and liquid phase product by a high pressure separator, wherein the temperature of the high pressure separator is controlled at 200° C. to 350° C.; the liquid phase product is separated into hydrogenated light oil and hydrogenated heavy oil by a fractionating tower; The atmospheric distillation conditions described in step (1) are as follows: the tower top pressure is 0.04MPa to 0.12MPa; the atmospheric distillation feed temperature is 330°C to 390°C; The properties of the atmospheric residue oil described in step (1) are as follows: density is 0.95 g / cm 3 ~1.10g / cm 3 ; Nitrogen content is 0.2m% to 1.0m%; sulfur content is 2m% to 8m%; metal content is 20mg / kg to 200mg / kg; In step (2), the atmospheric residue oil is contacted with a hydrogenation protective agent, a hydrodemetallization catalyst and a hydrorefining catalyst in sequence to carry out a hydrotreating reaction; The operating conditions of the hydroprocessing reaction in step (2) are as follows: reaction pressure 14.0-20.0 MPa; average reaction temperature 360-400°C; liquid hourly volume space velocity 0.2-3.0 h -1 ; The volume ratio of hydrogen to oil is 600:1~1200:

1.

2. The method according to claim 1, characterized in that: Step (1) controls the nitrogen content in the liquid phase logistics after the hydroprocessing reaction to be 2000mg / kg to 3000mg / kg; Step (2) controls the cutting temperature of the hydrogenated light oil and the hydrogenated heavy oil to be 600℃ to 750℃.

3. The method according to claim 1, characterized in that: The properties of the crude oil described in step (1) are as follows: density 0.80 g / cm 3 ~1.10g / cm 3 ; Nitrogen content is 0.1m%~0.6m%; sulfur content is 1m%~6m%; metal content is 10mg / kg~100mg / kg.

4. The method according to claim 3, characterized in that: The properties of the crude oil described in step (1) are as follows: density 0.85 g / cm 3 ~0.95g / cm 3 ; Nitrogen content is 0.2m%~0.4m%; sulfur content is 2m%~4m%; metal content is 20mg / kg~60mg / kg.

5. The method according to claim 1, characterized in that: The properties of the atmospheric residue oil described in step (1) are as follows: density is 1.0 g / cm 3 ~1.05g / cm 3 ; Nitrogen content is 0.3m%~0.8m%; sulfur content is 4m%~6m%; metal content is 40mg / kg~100mg / kg.

6. The method according to claim 1, characterized in that: The atmospheric distillation conditions described in step (1) are as follows: the tower top pressure is 0.06MPa-0.10MPa; the atmospheric distillation feed temperature is 350°C-370°C.

7. The method according to claim 1, characterized in that: The material after the hydrotreatment reaction in step (3) is separated into gas phase products and liquid phase products through a high-pressure separator, and the temperature of the high-pressure separator is controlled at 230°C to 300°C.

8. The method according to claim 1, characterized in that: The reaction conditions described in step (4) are as follows: reaction pressure 10.0-35.0 MPa; average reaction temperature 150-450°C; liquid hourly volume space velocity 0.1-15.0 h -1 ; The volume ratio of hydrogen to oil is 100:1~2500:

1.

9. The method according to claim 8, characterized in that: The reaction conditions described in step (4) are as follows: reaction pressure 14.0-20.0 MPa; average reaction temperature 360-400°C; liquid hourly volume space velocity 0.2-3.0 h -1 ; The volume ratio of hydrogen to oil is 600:1~1500:

1.

10. The method according to claim 1, characterized in that: The reaction conditions described in step (5) are as follows: reaction pressure 10.0-35.0 MPa; average reaction temperature 150-450°C; liquid hourly volume space velocity 0.1-15.0 h -1 ; The volume ratio of hydrogen to oil is 100:1~2500:

1.

11. The method according to claim 10, characterized in that: The reaction conditions described in step (5) are as follows: reaction pressure 14.0-10.0 MPa; average reaction temperature 380-420°C; liquid hourly volume space velocity 0.2-3.0 h -1 ; The volume ratio of hydrogen to oil is 1000:1~1600:1.

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