Method for processing residual oil hydrogenated diesel oil

Abstract

The invention relates to a method for processing residual oil hydrogenated diesel oil, which adopts a hydrocracking technology, that is, the residual oil hydrogenated diesel oil is used as a raw material of a hydrocracking unit for processing, and the hydrocracking unit is a light oil type hydrocracking unit. The method provided by the invention widens the raw material source of the device, optimizes the processing route of the residual oil hydrogenated diesel oil, provides a successful case for the optimized utilization of the residual oil hydrogenated diesel oil, most of the residual oil hydrogenated diesel oil components are converted into gasoline components, the diesel oil components are effectively reduced, and the product structure is optimized. As a raw material of a hydrocracking unit, the residual oil hydrogenated diesel oil is beneficial to increasing the cetane number of a diesel oil product, reducing the sulfur content of the diesel oil product, improving the feeding property of a reforming unit and improving the product quality.

Description

Technical Field

[0001] The invention relates to a method for processing residual oil hydrogenated diesel. Background Art

[0002] As the main production unit of clean fuel, the hydrocracking unit has gradually become an indispensable unit for the quality upgrade of refineries due to its excellent product properties and flexible production scheme. The hydrocracking unit plays a certain role in reducing the compression of diesel. It is a common practice to maximize the production of non-diesel products such as light naphtha, heavy naphtha or jet fuel by appropriately processing diesel components such as catalytic diesel and straight-run diesel. Residue hydrogenated diesel is one of the main products of residue hydrogenation. How to achieve high added value utilization of residue hydrogenated diesel is an urgent problem to be solved by researchers and refining companies. There are no reports on the processing of residue hydrogenated diesel by hydrocracking. The present invention mainly studies the processing of residue hydrogenated diesel by hydrocracking unit, and provides a reference for the processing route of residue hydrogenated diesel.

[0003] ①CN110655954A discloses a method for ultra-deep desulfurization of residual oil hydrogenated diesel, which comprises the following steps: a. fractionating the residual oil hydrogenated diesel to obtain a light fraction and a heavy fraction, wherein the cut point temperature of the light fraction and the heavy fraction is 331-355°C; b. subjecting the light fraction obtained in step a to a hydrodesulfurization treatment to obtain a first part of ultra-low sulfur diesel fraction; c. subjecting the heavy fraction obtained in step a to an oxidative desulfurization treatment to obtain a second part of ultra-low sulfur diesel fraction. The method can effectively remove sulfur-containing compounds from residual oil hydrogenated diesel, and compared with the prior art, it reduces the severity of the diesel hydrogenation unit, prolongs the operating time of the diesel hydrogenation unit, and can reduce the amount of oxidant and extractant used, with a high oil yield and good economic benefits. The first part of the ultra-low sulfur diesel fraction and the second part of the ultra-low sulfur diesel fraction are mixed to obtain an ultra-low sulfur diesel product with a sulfur content of 7.1 μg / g.

[0004] ②Xu Dahai, Niu Shikun and others conducted a feasibility study on the production of diesel that meets the GB19147-2016 automotive diesel standard (National V automotive diesel standard) by blending a diesel hydrogenation unit with a diesel fraction produced by an ebullated bed residue oil hydrogenation unit (referred to as ebullated bed hydrogenated diesel). The results show that conventional diesel hydrogenation units can produce National V automotive diesel blending components by blending a certain proportion of ebullated bed hydrogenated diesel fractions; straight-run diesel blended with 30% ebullated bed hydrogenated diesel at a reaction pressure of 6.5 MPa and a volume space velocity of 1.5 h －1Under the conditions of reaction temperature of 360℃ and hydrogen-to-oil volume ratio of 500, refined diesel meets the National V diesel standard for vehicles; mixed diesel (the mass ratio of straight-run diesel, coking diesel and catalytic cracking diesel is 62:25:13) is blended with 30% boiling bed hydrogenated diesel, and the reaction pressure is 7.3MPa and the volume space velocity is 1.0h -1 Under the conditions of reaction temperature of 355℃ and hydrogen-to-oil volume ratio of 500, automotive diesel blending components with sulfur content meeting the National V standard can be produced.

[0005] ③ Fan Siqiang, Chen Pingping and others processed residual oil hydrogenated diesel by three routes: hydrofining, hydromodification and mixed LCO hydromodification. Under the experimental conditions in the article, the refined oil obtained by the hydrofining route only increased the cetane index by 2.25 units, and could not reduce the diesel production, so the technical advantage was not great; the hydromodification route can convert residual oil hydrogenated diesel into light naphtha, heavy naphtha and other chemical raw materials, and significantly improve the quality of diesel products. At a reforming temperature of 375°C, a 42% heavy naphtha fraction can be obtained, and its aromatic potential is 54%, which is a high-quality catalytic reforming raw material. At the same time, 49% of modified diesel can be obtained, the cetane index reaches 51.5, the mass fraction of polycyclic aromatic hydrocarbons is less than 2.5%, and the mass fractions of sulfur and nitrogen are less than 10μg / g, which meets the National VI diesel standard. This technology has certain market competitiveness; combined with the characteristics of LCO such as poor properties, great processing difficulty, small output of residual oil hydrogenated diesel and excellent properties, LCO is mixed with residual oil hydrogenated diesel for hydrogenation and modification, with low operating load, large processing capacity and excellent product quality. It is an effective technical route for enterprises to reduce diesel production and realize high added value utilization of diesel.

[0006] ④ Zhang Wei conducted a hydrogenation process test on the production of National VI standard diesel by hydrogenation of ebullated bed residue oil hydrogenation diesel fraction. The results showed that the hydrogenation of ebullated bed residue oil hydrogenation diesel fraction as raw material, under the reaction pressure of 6.5-7.5MPa and volume space velocity of 1.0-1.5h -1 , under the process conditions of average reaction temperature of 350-375℃ and hydrogen-to-oil volume ratio of 400, various indicators of refined diesel (except cetane number) can meet the National VI automotive diesel standard. As the distillation range of the boiling bed residue oil hydrogenated diesel fraction becomes heavier, the difficulty of hydrodesulfurization increases significantly. It is recommended to control the final distillation point to no more than 340℃ when producing National VI standard diesel, which is conducive to the long-term operation of the hydrogenation unit under milder operating conditions. When it is necessary to process the boiling bed hydrogenated diesel fraction with a heavier distillation range, it is recommended to blend it into the existing diesel hydrorefining unit or diesel hydromodification unit in a certain proportion to reduce the processing difficulty.

[0007] Through the investigation of patents, literature and other materials, it is found that the conventional processing method of residual oil hydrotreated diesel uses diesel refining or diesel hydro-modification technology to produce qualified diesel products, but these methods have problems such as low cetane number of diesel products and low ability to convert diesel into non-diesel components. Summary of the invention

[0008] The purpose of the present invention is to provide a method for processing residual oil hydrogenated diesel, which adopts hydrocracking technology to process residual oil hydrogenated diesel. The method broadens the raw material source of the device, optimizes the residual oil hydrogenated diesel processing route, effectively reduces the diesel component, optimizes the product structure, and improves the quality of the diesel product.

[0009] The object of the invention is achieved in this way:

[0010] The method for processing residual oil hydrogenated diesel of the present invention adopts hydrocracking technology, that is, using residual oil hydrogenated diesel as the raw material of hydrocracking device for processing.

[0011] The method for processing residual oil hydrogenated diesel of the present invention is that the residual oil hydrogenated diesel enters the diesel component intermediate tank area, and then enters the hydrocracking unit through the diesel pipeline of the diesel component intermediate tank area.

[0012] The method for processing residual oil hydrogenated diesel of the present invention is that the residual oil hydrogenated diesel enters the hydrocracking unit through the diesel line of the hydrocracking unit from the diesel component intermediate tank area, enters the raw oil buffer tank together with the vacuum wax oil as the raw material of the hydrocracking unit, the raw oil is pressurized to 18.0MPa by the reaction feed pump and mixed with circulating hydrogen, and after being heated to 350-370°C by the reaction feed heating furnace, enters the hydrorefining reactor for desulfurization, denitrogenation and dearomatization reaction, and the refining reaction temperature is 350-390°C; then enters the hydrocracking reactor for cracking reaction, and the cracking reaction temperature is 350-400°C. After the reaction product is separated into gas and liquid by the high and low pressure separator and the stripping tower, the bottom oil of the stripping tower is heated to 350-370°C by the fractionation feed heating furnace, and then enters the fractionation tower for separation, and produces naphtha, aviation kerosene and diesel products.

[0013] The method for processing residual oil hydrogenated diesel of the present invention comprises the following steps: the residual oil hydrogenated diesel enters the device from the diesel component intermediate tank area through the diesel line of the hydrocracking device, and enters the raw oil buffer tank together with the vacuum wax oil; the blending ratio of the residual oil hydrogenated diesel is 21.4%; the raw oil is pressurized by a reaction feed pump and mixed with circulating hydrogen; and the hydrogen-to-oil ratio is greater than 1137.

[0014] The method for processing residual oil hydrogenated diesel of the present invention comprises a hydrocracking device which is a light oil type hydrocracking device, which is composed of reaction, fractionation, desulfurization and public engineering parts, adopts a one-stage full-cycle hydrocracking process, uses vacuum wax oil as the main raw material, adopts HYT-6219-1.3T and KF-848-1.3Q as the hydrorefining catalyst, adopts HC-24L and HC-120 as the hydrocracking catalyst, and has an operating pressure of 14.7 MPa; the products are crude liquefied gas, light naphtha, heavy naphtha, aviation kerosene and diesel, and the cetane number index is ≧60.

[0015] The method for processing residual oil hydrogenated diesel of the present invention, the hydrocracking device adopts high pressure hydrocracking technology, and the operating pressure of the device is 14.7MPa.

[0016] The method for processing residual oil hydrogenated diesel of the present invention, the residual oil hydrogenated diesel is one of the products of the fixed bed residual oil hydrogenation device, and belongs to the diesel component.

[0017] The method for processing residual oil hydrogenated diesel of the present invention converts most of the residual oil hydrogenated diesel into non-diesel components, including naphtha, jet fuel and liquefied gas, after being processed by a hydrocracking unit.

[0018] Introducing the residue oil hydrotreated diesel into a hydrocracking unit with a higher operating pressure for processing, on the one hand, improves the hydrorefining effect, making it easier to carry out reactions such as aromatic saturation and heteroatom removal, thereby obtaining high-quality diesel products; on the other hand, it plays the role of the hydrocracking reaction, carries out cracking reactions on the residue oil hydrotreated diesel, and simultaneously obtains some high value-added components such as jet fuel and gasoline. The use of hydrocracking technology to process residue oil hydrotreated diesel is the preferred process technology route.

[0019] Compared with the existing methods, the method provided by the present invention has the following advantages:

[0020] (1) The hydrocracking unit processes residual oil hydrogenated diesel, which broadens the raw material source of the unit, optimizes the processing route of residual oil hydrogenated diesel, and provides a successful case for the optimal utilization of residual oil hydrogenated diesel.

[0021] (2) After the hydrocracking unit processes the residual oil hydrogenated diesel, the light naphtha + heavy naphtha yield is 38.13%, which is 21.72% higher than the 16.41% yield of hydrogenated modified naphtha; the apparent conversion rate of the residual oil hydrogenated diesel is 67.11% (conversion rate = 1-diesel non-conversion rate = 1-diesel yield), which means that most of the residual oil hydrogenated diesel components are converted into non-diesel components, which effectively reduces the diesel component and optimizes the product structure. There is still room for adjustment of the product yield of the unit, and the yields of diesel, jet fuel and naphtha can be further adjusted according to the company's production and operation conditions.

[0022] (3) After the residue oil hydrotreated diesel is processed by the hydrocracking unit, the cetane number of the diesel product is 62.7. However, compared with the designed cetane number of 49.6 for the hydrotreated diesel product, the cetane number of the diesel is greatly improved; compared with the cetane number of 40.8 for the residue oil hydrotreated diesel (see Table 1), the cetane number is increased by 21.9 units; the aromatic potential of heavy naphtha is increased by 2.2 units.

[0023] (4) Before and after the hydrocracking unit blended the residual oil with hydrogenated diesel, the sulfur and nitrogen contents of the diesel product were 1.3 mg / kg and

[0024] <0.3mg / kg, which is a significant improvement compared to the sulfur content of 1.8mg / kg in diesel products from the diesel hydro-reforming unit.

[0025] (5) Residue oil hydrogenated diesel is processed using hydrocracking technology, which is beneficial to improving the cetane number of diesel in the entire plant, reducing the sulfur content of diesel products, improving the feed properties of the reforming unit, and improving the quality of the products in the entire plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the process flow chart of residual oil hydrogenation diesel processing. Specific implementation method:

[0027] Figure 1 Among them, residue oil hydrogenated diesel 1, vacuum wax oil 2, raw oil buffer tank 3, reaction feed pump 4, reaction feed heating furnace 5, hydrotreating reactor 6, hydrocracking reactor 7, fractionation feed heating furnace 8, fractionation tower 9, naphtha 10, jet fuel 11, diesel 12, and tail oil 13.

[0028] The residual oil hydrogenated diesel 1 and the vacuum wax oil 2 enter the raw oil buffer tank 3 together as the raw material of the hydrocracking unit (the blending ratio of the residual oil hydrogenated diesel is 21.4%). The raw oil is pressurized to 18.0MPa by the reaction feed pump 4 and mixed with circulating hydrogen (hydrogen-oil ratio is greater than 1137). After being heated to 350-370°C by the reaction feed heating furnace 5, it enters the hydrofining reactor 6 for desulfurization, denitrogenation, dearomatization and other reactions, and the refining reaction temperature is 350-390°C; then it enters the hydrocracking reactor 7 for cracking reaction, and the cracking reaction temperature is 350-400°C. After the reaction product is separated into gas and liquid by the high and low pressure separator and the stripping tower, the bottom oil of the stripping tower is heated to 350-370°C by the fractionation feed heating furnace 8, and then enters the fractionation tower 9 for separation, producing naphtha 10, jet fuel 11, and diesel product 12.

[0029] The hydrocracking unit was used for the first processing of residual oil hydrogenated diesel test. The blending amount of residual oil hydrogenated diesel was 30t / h, the total feed of the unit was 140t / h, and the blending ratio was 21.4%. The specific implementation steps are as follows:

[0030] (1) Increase the amount of residual oil hydrogenated diesel blending by 5t / h. As the amount of residual oil hydrogenated diesel feed increases, reduce the amount of vacuum wax oil feed synchronously, and keep the total feed of the device unchanged at 140t / h. After the device is blended with 10t / h of residual oil hydrogenated diesel, the operating conditions are controlled as follows: reaction pressure 14.7MPa, average refining reaction temperature 360℃, average cracking reaction temperature 359℃, hydrogen-oil volume ratio 1160, refining reactor 6 single bed temperature rise ≤42℃, cracking reactor 7 single bed temperature rise ≤28℃, cold hydrogen valve opening ≤65%, high and low liquid separation tanks, stripping tower, fractionation tower 9 liquid level controlled at 55%, fractionation feed heating furnace 8 outlet temperature controlled at 360℃. Appropriately adjust the refining reaction temperature and cracking reaction temperature to stabilize the reaction depth, keep the heavy naphtha yield at 36%, and operate stably for 24 hours.

[0031] (2) Increase the amount of residual oil hydrogenated diesel blending by 5t / h. As the amount of residual oil hydrogenated diesel feed increases, reduce the amount of vacuum wax oil feed synchronously to keep the total feed of the device unchanged at 140t / h. After the device is blended with 20t / h of residual oil hydrogenated diesel, the operating conditions are controlled as follows: reaction pressure 14.7MPa, average refining reaction temperature 360℃, cracking reaction temperature 357℃, hydrogen-oil volume ratio 1187, refining reactor 6 single bed temperature rise ≤42℃, cracking reactor 7 single bed temperature rise ≤28℃, cold hydrogen valve opening ≤65%, high and low liquid separation tanks, stripping tower, fractionation tower 9 liquid level controlled at 55%, fractionation feed heating furnace 8 outlet temperature controlled at 360℃. Appropriately adjust the refining reaction temperature and cracking reaction temperature to stabilize the reaction depth, keep the heavy naphtha yield at 36%, and operate stably for 24 hours.

[0032] (3) Increase the amount of residual oil hydrogenated diesel blended by 5t / h. As the amount of residual oil hydrogenated diesel feed increases, reduce the amount of vacuum wax oil feed synchronously to keep the total feed of the device unchanged at 140t / h. After the device is blended with 30t / h of residual oil hydrogenated diesel, the operating conditions are controlled as follows: reaction pressure 14.7MPa, average refining reaction temperature 360℃, average cracking reaction temperature 355.4℃, hydrogen-oil volume ratio 1201, refining reactor 6 single bed temperature rise ≤42℃, cracking reactor 7 single bed temperature rise ≤28℃, cold hydrogen valve opening ≤65%, high and low liquid separation tanks, stripping tower, fractionation tower 9 liquid level controlled at 55%, fractionation feed heating furnace 8 outlet temperature controlled at 360℃. Appropriately adjust the refining reaction temperature and cracking reaction temperature to stabilize the reaction depth (reference hydrogen consumption per ton of oil 330~345Nm 3 / h), maintaining the heavy naphtha yield at 33%-37%.

[0033] (4) During the blending process, the speed of the hydrogen circulation machine is gradually adjusted to 7700rpm~8200rpm according to the bed temperature rise and the opening of the cold hydrogen valve to ensure the cold hydrogen capacity and the appropriate hydrogen-to-oil ratio (1137~1400Nm 3 / m 3), the opening of the cold hydrogen valve of the cracking reactor is not allowed to exceed 65% under any circumstances.

[0034] (5) After the blended residue oil and hydrogenated diesel are stabilized, the raw materials and products are sampled and analyzed, and data is collected; the material balance and energy consumption of the device are statistically analyzed, and the process parameters are fine-tuned according to the product distribution.

[0035] Changes in raw materials

[0036] The properties of residual oil hydrogenated diesel are shown in Table 1.

[0037] Table 1 Properties of residual oil hydrogenated diesel

[0038]

[0039] After the hydrocracking unit blends the residual oil with hydrogenated diesel, the distillation range, sulfur and nitrogen of the mixed raw material are slightly reduced, and other changes are not significant, which meets the raw material index requirements of the hydrocracking unit. See Table 2 for details.

[0040] Table 2 Changes in properties of mixed crude oil

[0041]

[0042]

[0043] Process parameters

[0044] After the hydrocracking unit blended the residual oil with hydrogenated diesel, the sulfur and nitrogen content in the raw materials decreased, and the temperature rise of the refining bed decreased. The inlet temperature of the refining bed was appropriately increased to ensure that the average refining reaction temperature remained basically unchanged. In order to ensure the appropriate yield of diesel products, the cracking catalyst bed temperature was reduced. Affected by the change of raw materials and the depth of reaction, the consumption of new hydrogen decreased by 4400Nm 3 / h, the changes in process parameters are shown in Table 3:

[0045] Table 3 Main process parameters of the device

[0046]

[0047] Comparative Example 1

[0048] The original design of residual oil hydro-diesel was to be processed in the diesel hydro-reforming unit to remove sulfur and nitrogen and improve the diesel cetane number. The main data comparison between the hydro-cracking unit and the diesel hydro-reforming unit is shown in Table 4:

[0049] Table 4 Comparison of main data of hydrocracking and diesel hydroreforming units

[0050]

[0051] Example 1

[0052] Product distribution: After the hydrocracking unit blends the residual oil with hydrogenated diesel, the yield of each product in the unit is shown in Table 5:

[0053] Table 5 Comparison of product yields of residual oil hydrogenation diesel unit

[0054]

[0055] The final distillation point of the jet fuel product of the hydrocracking unit is controlled from about 250°C to about 230°C, and a part of the jet fuel components are compressed into the diesel product, resulting in a lower jet fuel yield than the design value and a higher diesel yield than the design value. At the same time, due to the high cetane number and good product quality of the hydrocracking unit, the appropriate diesel yield is guaranteed according to the company's production needs, and the cracking reaction depth is appropriately reduced, which is manifested in a 4.22% increase in diesel yield, a 3.09% decrease in heavy naphtha yield, a 1.52% decrease in light naphtha yield, a 0.83% decrease in liquefied gas yield, and little change in the yields of other products.

[0056] After the hydrocracking unit processes the residual oil hydrogenated diesel, the apparent conversion rate of the residual oil hydrogenated diesel is 67.11% (conversion rate = 1-diesel non-conversion rate = 1-diesel yield), which means that most of the residual oil hydrogenated diesel is converted into non-diesel components. In view of the flexibility of the hydrocracking unit production, the reaction temperature has a large room for adjustment, and the diesel and naphtha yields can be adjusted and optimized according to the company's production and operation conditions.

[0057] Product quality: During the processing of residual oil hydrogenated diesel, the main indicators of diesel cetane number, sulfur, nitrogen, etc. are investigated. The specific data are shown in Table 6:

[0058] Table 6 Product quality comparison

[0059]

[0060] Since residual oil hydrotreated diesel contains a large amount of paraffins and monocyclic cycloalkanes, the cetane number of diesel before and after the hydrocracking unit is blended with residual oil hydrotreated diesel does not change much, but it is greatly improved compared to the design value of 44.5 of diesel cetane number of the hydro-reforming unit. Compared with the cetane number of 40.8 of residual oil hydrotreated diesel (see Table 1), the cetane number has increased by 21.9 units.

[0061] Before and after the hydrocracking unit blends the residual oil with hydrogenated diesel, the sulfur and nitrogen contents of the diesel product are 1.3 mg / kg and <0.3 mg / kg respectively, but compared with the sulfur content of 1.8 mg / kg of the diesel product from the diesel hydro-reforming unit, it has increased significantly.

[0062] The aromatic potential of heavy naphtha increased from 33.6 to 35.8. The main reason was that during the blending of residue oil with hydrogenated diesel, the temperature of the cracking bed was reduced to ensure the appropriate yield of diesel products. The temperature reduction was not conducive to the saturation of aromatics and the ring-opening and chain-breaking reactions, which led to an increase in the aromatic potential of heavy naphtha.

[0063] Energy consumption of the unit: before and after the hydrocracking unit blended with residual oil and hydrogenated diesel, the energy consumption of the unit decreased by 1.47kgEO / t. The main reasons were that the sulfur and nitrogen content of the raw materials decreased, the temperature rise of the refining bed decreased, the amount of cold hydrogen decreased, and the steam consumption of the circulating hydrogen compressor decreased by 1.39kgEO / t; the yield of light component products such as light and heavy naphtha decreased, which reduced the top load of the fractionation system and the consumption of air cooling and water cooling; the consumption of new hydrogen decreased, resulting in a decrease in the power consumption of the new hydrogen compressor. The energy consumption of the unit is shown in Table 7.

[0064] Table 7 Changes in energy consumption of the device

[0065]

[0066] By comparing the comparative examples with the embodiments, it can be seen that:

[0067] (1) After the residue oil hydrogenated diesel is processed by the hydrocracking unit, the light naphtha + heavy naphtha yield is 38.13%, which is 21.72% higher than the hydrogenated modified naphtha yield of 16.41%; the apparent conversion rate of the residue oil hydrogenated diesel is 67.11% (conversion rate = 1-diesel unconversion rate = 1-diesel yield), which means that most of the residue oil hydrogenated diesel components are converted into non-diesel components, which effectively reduces the diesel component and optimizes the product structure.

[0068] (2) After the hydrocracking unit processes the residual oil hydrogenated diesel, the cetane number of the diesel product is 62.7, which is significantly higher than the cetane number of 44.5 of the hydrogenated diesel; the cetane number is 21.9 units higher than the cetane number of the residual oil hydrogenated diesel of 40.8 (see Table 1); before and after the hydrocracking unit blends the residual oil hydrogenated diesel, the sulfur and nitrogen contents of the diesel product are 1.3 mg / kg and <0.3 mg / kg, respectively, which is a certain increase compared to the sulfur content of 1.8 mg / kg of the diesel product of the diesel hydrogenation unit; the aromatic potential of heavy naphtha increases by 2.2 units. Residue oil hydrogenated diesel as a raw material for the hydrocracking unit is conducive to improving the cetane number of the diesel of the whole plant, improving the feed properties of the reforming unit, and improving the quality of the products of the whole plant.

[0069] Example 2

[0070] According to the company's production needs, the hydrocracking unit processes residual oil hydrogenated diesel under high load conditions (95% load), with a total feed of 240t / h, of which residual oil hydrogenated diesel is 30t / h, and the blending ratio is 12.5%. The operating conditions are: reaction pressure 14.7MPa, refining reaction temperature 377℃, cracking reaction temperature 380℃, hydrogen-oil volume ratio 1250, refining reactor single bed temperature rise ≦42℃, cracking reactor single bed temperature rise ≦28℃, cold hydrogen valve opening ≦65%, high and low liquid separation tanks, stripping tower, fractionation tower liquid level control at 55%, fractionation feed heating furnace outlet temperature control at 363℃.

[0071] After the hydrocracking unit blends the residual oil with hydrogenated diesel, the yields of the various products in the unit are shown in Table 8:

[0072] Table 8 Product yield of residual oil hydrogenation diesel unit

[0073]

[0074] After the hydrocracking unit processes the residual oil hydrogenated diesel, the apparent conversion rate of the residual oil hydrogenated diesel is 69.09% (conversion rate = 1-diesel non-conversion rate = 1-diesel yield), which means that most of the residual oil hydrogenated diesel components are converted into non-diesel components, effectively reducing the diesel component. In view of the flexibility of the hydrocracking unit production, there is still a large room for adjustment of the reaction temperature, and there is still a certain room for adjustment of the unit product yield. The diesel and naphtha yields can be adjusted and optimized according to the company's production and operation conditions to further increase the conversion rate of the residual oil hydrogenated diesel.

[0075] During the processing of residual oil hydrogenated diesel, the main indicators of diesel cetane number, sulfur, nitrogen, etc. are investigated. The specific data are shown in Table 9:

[0076] Table 9 Product quality comparison

[0077]

[0078] Before and after the hydrocracking unit is blended with residual oil and hydrogenated diesel, the cetane number of the diesel product is 61.9, which is a significant improvement over the diesel hydro-reforming unit; the sulfur and nitrogen contents of the diesel product are 1.6 mg / kg and <0.3 mg / kg, respectively, but compared with the sulfur content of 1.8 mg / kg of the diesel product of the diesel hydro-reforming unit, there is a certain improvement. The cetane number of the diesel product is slightly lower than that of Example 1, and the sulfur content is slightly higher, which is mainly related to the high load of the unit, but there is a certain improvement compared with the diesel hydro-reforming unit.

Claims

1. A method for processing residual oil hydrogenated diesel, characterized in that: The method adopts the hydrocracking technology, that is, using residual oil hydrogenated diesel as the raw material of the hydrocracking unit for processing.

2. A method for processing residual oil hydrogenated diesel according to claim 1, characterized in that: The method is that the residual oil hydrogenated diesel enters the diesel component intermediate tank area, and then the diesel component intermediate tank area enters the hydrocracking unit through the diesel pipeline of the hydrocracking unit.

3. A method for processing residual oil hydrogenated diesel according to claim 1, characterized in that: The method comprises the following steps: the residual oil hydrogenated diesel enters the hydrocracking unit from the diesel component intermediate tank area through the hydrocracking unit start-up diesel line, enters the raw oil buffer tank together with the reduced pressure wax oil as the raw material of the hydrocracking unit, the raw oil is pressurized to 18.0MPa by a reaction feed pump, mixed with circulating hydrogen, heated to 350-370°C by a reaction feed heating furnace, and then enters the hydrorefining reactor for desulfurization, denitrogenation and dearomatization reactions, the refining reaction temperature is 350-390°C; then enters the hydrocracking reactor for cracking reaction, the cracking reaction temperature is 350-400°C; the reaction product is separated into gas and liquid by a high-low pressure separator and a stripping tower, the bottom oil of the stripping tower is heated to 350-370°C by a fractionation feed heating furnace, and then enters the fractionation tower for separation, so as to produce naphtha, jet fuel and diesel products.

4. The method for processing residual oil hydrogenated diesel as claimed in claim 3, characterized in that: The residual oil hydrogenated diesel enters the device from the diesel component intermediate tank area through the hydrocracking unit start-up diesel line, and enters the raw oil buffer tank together with the vacuum wax oil. The blending ratio of the residual oil hydrogenated diesel is 21.4%. The raw oil is pressurized by the reaction feed pump and mixed with circulating hydrogen, and the hydrogen-to-oil ratio is greater than 1137.

5. A method for processing residual oil hydrogenated diesel according to claim 1, characterized in that: The hydrocracking unit is a light oil type hydrocracking unit, which consists of reaction, fractionation, desulfurization and public engineering parts, adopts a one-stage full-cycle hydrocracking process, uses vacuum wax oil as the main raw material, uses HYT-6219-1.3T and KF-848-1.3Q as hydrorefining catalysts, and uses HC-24L and HC-120 as hydrocracking catalysts. The operating pressure is 14.7MPa; the products are crude liquefied gas, light naphtha, heavy naphtha, aviation kerosene, and diesel, and the cetane number index is ≧60.

6. The method for processing residual oil hydrogenated diesel as claimed in claim 1, characterized in that: The hydrocracking unit adopts high-pressure hydrocracking technology, and the operating pressure of the unit is 14.7 MPa.

7. The method for processing residual oil hydrogenated diesel as claimed in claim 1, characterized in that: The residual oil hydrogenated diesel is one of the products of a fixed bed residual oil hydrogenation device and belongs to a diesel component.

8. The method for processing residual oil hydrogenated diesel as claimed in claim 1, characterized in that: After being processed by the hydrocracking unit, most of the residue oil hydrotreated diesel is converted into non-diesel components, including naphtha, jet fuel, and liquefied gas.

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