A solvent deasphalting extraction tower and a solvent deasphalting method

Abstract

The present invention provides a solvent deasphalting extraction tower and a solvent deasphalting method, wherein the extraction tower comprises an extraction section and a settling section, wherein the extraction section is located below the settling section, a feed port for crude oil is provided on the side wall of the tower body between the extraction section and the settling section, a feed port for solvent for the extraction section is provided below the extraction section, and at least two feed ports for high-temperature solvent for the settling section are uniformly provided along the axial direction on the side wall of the settling section. The present invention is improved on the basis of the original structure of the extraction tower, the extraction section is designed as a whole, and the temperature is kept basically consistent, the soluble components in the crude oil are dissolved to the maximum extent, the volume of the extraction section is reduced, and thus the back mixing during the extraction process is reduced; the present invention arranges a plurality of high-temperature solvent feed ports in the settling section, thereby replacing the arrangement of an external heat exchange pipeline, ensuring uniform temperature distribution in the settling section, uniformly heating the oil product coming up from the lower part of the extraction tower, and improving the yield of deasphalted oil; the extraction tower has a simple structure, significant improvement effect, and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical industry and relates to a solvent deasphalting extraction tower and a solvent deasphalting method. Background Art

[0002] Oil processing technology usually uses crude oil as the source. After atmospheric and vacuum distillation, it will produce a variety of distillate oils, such as gasoline, diesel, wax oil and heavy oil. Due to the complex composition of heavy oil, there are many subsequent processing processes, which will produce a variety of oil products, such as residual oil, hydrocracking tail oil, etc. Solvent extraction uses the different solubility of solvents in heavy oil to separate components. It can separate heavy metals and asphaltene in the raw materials at low temperatures, so it is also called solvent deasphalting process.

[0003] The raw materials for solvent deasphalting are mostly residual oil. As one of the important means of deep processing of residual oil, it utilizes the different solubility of light hydrocarbon solvents such as propane and butane on the components in the residual oil to separate deasphalted oil rich in saturated hydrocarbons and aromatics from the residual oil, and at the same time obtain deoiled asphalt rich in colloids and asphaltene. Since the metal compounds basically enter the deoiled asphalt, the content of impurities such as condensed ring compounds, metals, sulfur, nitrogen, etc. in the deasphalted oil is relatively low, which is a raw material with better quality for producing lubricating oil, and can also be used as a raw material for catalytic cracking or hydrocracking.

[0004] The extraction tower is the core equipment of the solvent deasphalting device. The separation effect directly affects the yield and quality of the product. Traditional extraction towers include baffle towers, mechanical turntable towers, etc. In recent years, new packing towers have also been developed, such as the honeycomb grid regular packing extraction tower disclosed in CN2090288U, whose internal structure is mainly a porous rib-by-time liquid distributor, a honeycomb grid regular packing and a corrugated plate packing support; the packing extraction tower with a redistributor or a vertical baffle disclosed in CN 102698465A, etc., can achieve the improvement of mass transfer and heat transfer performance and extraction and separation efficiency. The internal components in the extraction tower play a role in inhibiting the continuous phase from mixing back and promoting dispersed mass transfer during the extraction process, but the viscosity of heavy oil is usually high, and complex internal components are prone to cause grid or packing deposition and blockage, which in turn affects the mass transfer and heat transfer effect.

[0005] CN 105567300A discloses a solvent deasphalting extraction tower and a solvent deasphalting method. The inner space of the tower body of the extraction tower is provided with a filler extraction and separation zone, a solvent distribution zone and a heavy component collection zone in order from top to bottom. The filler extraction and separation zone includes a sedimentation separation zone and a solvent countercurrent extraction zone. The sedimentation separation zone is provided with a heat exchanger and at least one group of filler components. The solvent countercurrent extraction zone is provided with a plurality of groups of stacked filler components and support beams. In the structure of the extraction tower, there is still a problem that the light components generated in the extraction section are contaminated by new residual oil during the rising process, causing back mixing, and the sedimentation section adopts an external heating method, which has the disadvantage of uneven temperature distribution.

[0006] CN 105586076A discloses a method for separating crude oil. The method involves distilling the crude oil under atmospheric pressure to obtain atmospheric residue, which is then introduced into an extraction tower for extraction using a main extraction solvent to obtain a primary extract. The primary extract passes through at least three temperature gradient zones with successively increasing temperatures from bottom to top and reaches the top of the tower. Side line extracts are taken out respectively through side extraction lines respectively arranged in each temperature gradient zone, and a tower top extract is led out from the top of the tower. The method does not focus on the structure of the extraction tower for the extraction treatment of atmospheric residue, and the sedimentation section still adopts a multi-stage external heat exchange method, which is likely to cause the problem of uneven temperature distribution, and no solution is mentioned for the back-mixing problem that may exist in the extraction section.

[0007] In summary, for the equipment and process used in solvent deasphalting, the structure of the extraction tower needs to be improved so that it can reduce the amount of solvent used and the backmixing in the extraction section, ensure the uniformity of the temperature distribution in the sedimentation section, improve the quality and yield of the deasphalted oil, and reduce energy consumption. Summary of the invention

[0008] In view of the problems existing in the prior art, the object of the present invention is to provide a solvent deasphalting extraction tower and a solvent deasphalting method, wherein the solvent deasphalting is performed by using an extraction tower, the soluble components in the crude oil are fully dissolved through the overall design and temperature setting of the extraction section, and multiple high-temperature solvent inlets are set in the sedimentation section to replace the external heating medium, thereby ensuring uniform temperature distribution in the sedimentation section, reducing the loss of deasphalted oil due to local overheating, and helping to improve the yield of the deasphalted oil.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] On the one hand, the present invention provides a solvent deasphalting extraction tower, which includes an extraction section and a sedimentation section. The extraction section is located below the sedimentation section. A crude oil feed port is provided on the side wall of the tower body between the extraction section and the sedimentation section. An extraction section solvent feed port is provided below the extraction section. At least two sedimentation section high-temperature solvent feed ports are evenly arranged on the side wall of the sedimentation section along the axial direction.

[0011] In the present invention, various heavy oil components generated during crude oil processing need to be further processed. Solvent deasphalting is one of the important processes for deep processing. In the present invention, an extraction tower is used for solvent deasphalting, wherein the structure of the extraction tower is improved on the basis of the original division of the extraction section and the sedimentation section. The extraction section is designed as a whole and the temperature is kept basically consistent, so that the soluble components in the raw oil are dissolved to the maximum extent, and the volume of the extraction section is reduced, thereby reducing the back mixing during the extraction process; a plurality of high-temperature solvent feed ports are arranged in the sedimentation section to replace the arrangement of the external heat exchange pipeline, so as to ensure that the temperature distribution of the sedimentation section is uniform, and the oil product coming up from the lower part of the extraction tower is uniformly heated, so as to reduce the loss of deasphalted oil caused by local overheating, and alleviate the problem of excessive internal reflux, so as to improve the yield of deasphalted oil and reduce the content of impurities such as residual carbon therein; the extraction tower has a simple structure, a significant improvement effect and a low cost.

[0012] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0013] As a preferred technical solution of the present invention, the extraction tower is a packed tower, and packing layers are provided in both the extraction section and the sedimentation section.

[0014] Preferably, the packing layer in the extraction section is arranged as a whole.

[0015] Preferably, the packing layers in the sedimentation section are arranged at intervals, and the positions of the intervals correspond to the positions of the high-temperature solvent feed ports of the sedimentation section.

[0016] Preferably, the type of the packing includes structured packing or random packing.

[0017] In the present invention, the structured packing includes corrugated packing and / or grid packing, and the random packing includes any one of Raschig rings, Pall rings, conjugated rings, saddle rings or step rings, or a combination of at least two of them. Typical but non-limiting examples of the combination include: a combination of Raschig rings and Pall rings, a combination of Pall rings and conjugated rings, a combination of Raschig rings, conjugated rings and step rings, a combination of Raschig rings, Pall rings, conjugated rings and saddle rings, etc.

[0018] As a preferred technical solution of the present invention, the bottom of the extraction tower is a heavy phase settling zone, and is provided with a de-oiled asphalt outlet.

[0019] Preferably, a deasphalted oil outlet is provided at the top of the extraction tower.

[0020] Preferably, the number of the high-temperature solvent feed inlets in the settling section is 2 to 4, for example, 2, 3 or 4, and the high-temperature solvent feed inlets in the settling section are located on the same axis of the side wall of the tower body and are evenly arranged.

[0021] Preferably, a feed distributor is provided at the position of the high-temperature solvent feed port of each settling section, and a packing layer is provided above each feed distributor.

[0022] In the present invention, the feed distributor is arranged so that the high temperature solvent in the settling section can fully contact the oil extracted from the crude oil, and a packing layer is arranged above the feed distributor to provide a place for heat and mass transfer for the oil. If the separation accuracy is required to be high, the high temperature solvent in the settling section can be first heat exchanged with the ascending flow in the tower and then sprayed into the tower.

[0023] On the other hand, the present invention provides a method for solvent deasphalting using the above-mentioned solvent deasphalting extraction tower, the method comprising the following steps:

[0024] (1) The raw oil and the diluent solvent are mixed and added to the extraction tower, and then contacted with the extraction section solvent added at the bottom of the extraction tower in countercurrent to achieve preliminary separation of light and heavy components;

[0025] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the high-temperature solvent added to the settling section, the temperature of the settling section increases gradually from bottom to top, and the deasphalted oil is extracted from the top of the extraction tower;

[0026] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom, and the deoiled asphalt is extracted from the bottom of the extraction tower;

[0027] There is no particular order in which the operations of step (2) and step (3) are performed.

[0028] In the present invention, the solvent deasphalting process is developed and designed by utilizing the different solubility of the solvent to the substance under the critical state with the change of temperature and pressure. As the temperature rises, the solubility of the substance decreases, and the substance will precipitate from the solvent; there is a temperature gradient in the settling section of the extraction tower, and the temperature gradually rises from bottom to top. As the material rises, some light components will precipitate from the solvent, thereby achieving the purpose of purification, and the light components that have not precipitated will leave from the top of the tower together with the solvent.

[0029] As a preferred technical solution of the present invention, the type of the feedstock oil in step (1) includes any one of vacuum residue, atmospheric residue, heavy oil, inferior heavy oil or catalytic oil slurry, or a combination of at least two of them. Typical but non-limiting examples of the combination include: a combination of vacuum residue and atmospheric residue, a combination of heavy oil and inferior heavy oil, a combination of vacuum residue, heavy oil and catalytic oil slurry, a combination of vacuum residue, atmospheric residue, heavy oil and inferior heavy oil, etc.

[0030] Preferably, the dilution solvent in step (1) includes propane and / or butane.

[0031] Preferably, the volume ratio of the dilution solvent to the feedstock oil in step (1) is 0.4:1 to 0.6:1, for example 0.4:1, 0.45:1, 0.5:1, 0.55:1 or 0.6:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the addition temperature of the raw material oil and the dilution solvent after mixing in step (1) is 40-140°C, for example 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or 140°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] As a preferred technical solution of the present invention, the extraction stage solvent in step (1) includes propane and / or butane.

[0034] Preferably, the volume ratio of the extraction stage solvent to the feedstock oil in step (1) is 1:1 to 3:1, for example 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the temperature for adding the solvent in the extraction stage of step (1) is 40-140°C, for example, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or 140°C, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] In the present invention, the extraction section solvent is selected from propane, butane or a mixture thereof, and the feed amount is determined according to the dissolution requirement of the vacuum residue oil. In the present invention, the temperature of the extraction section is controlled to be substantially constant and consistent with the feed temperature of the feed oil, that is, the temperature of the extraction section from the feed oil inlet to the bottom of the extraction section is substantially consistent.

[0037] As a preferred technical solution of the present invention, the temperature of the extraction section in step (1) is kept consistent from top to bottom, which is the same as the addition temperature of the feedstock oil, so as to reduce energy consumption and reduce backmixing.

[0038] Preferably, the operating pressure of the extraction section in step (1) is 2.0 to 6.0 MPa, for example, 2.0 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, 4.0 MPa, 4.5 MPa, 5.0 MPa, 5.5 MPa or 6.0 MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the residence time of the extraction section in step (1) is 10 to 40 min, for example, 10 min, 15 min, 20 min, 25 min, 30 min or 40 min, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 15 to 20 min.

[0040] Preferably, the light components dissolved in the extraction stage solvent in step (1) include saturated components, aromatic components and light colloids.

[0041] In the present invention, the components that can be dissolved by the solvent in the extraction stage may vary depending on the type of raw oil, but according to the source and type of common heavy oil components, they usually include saturated fractions, aromatic fractions, colloids and asphaltenes, among which colloids are divided into light colloids and heavy colloids, which can be obtained by the heavy oil six-component analysis method.

[0042] As a preferred technical solution of the present invention, the settling section in step (2) is provided with 2 to 4 settling section high-temperature solvent feed ports, for example 2, 3 or 4, to respectively add the settling section high-temperature solvent.

[0043] Preferably, the high-temperature solvent in the settling section of step (2) includes propane and / or butane.

[0044] Preferably, the high-temperature solvent in the sedimentation section is a high-temperature solvent after supercritical recovery of deasphalted oil, and its temperature is 220-280°C, for example, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C or 280°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In the present invention, the type of high-temperature solvent selected in the sedimentation stage is the same as that of the solvent in the extraction stage, but the temperature is relatively high. At this time, the solvent is in a supercritical state. After mixing with the oil extracted in the extraction stage, the solubility of the solvent decreases due to the increase in temperature, and some light components are precipitated from the solvent, thereby achieving the purpose of purification.

[0046] In the present invention, the material produced from the deasphalted oil outlet at the top of the extraction tower is deasphalted oil carrying a large amount of solvent. After further heating in a heating furnace, it enters a deasphalted oil supercritical recovery tower for supercritical solvent recovery. The internal temperature and the temperature of the separated high-temperature solvent are 220-280° C. Most of the solvent has been recovered in this process. In order to reduce solvent loss, the material after solvent recovery will continue to enter the deasphalted oil stripping tower for stripping to recover the remaining solvent carried in the deasphalted oil; similarly, the material produced from the deoiled asphalt outlet will also enter the deoiled asphalt stripping tower for stripping after being heated to remove the solvent contained in the deoiled asphalt; the stripped solvent contains part of water vapor and cannot directly enter the settling section of the extraction tower, so only the solvent recovered by the deasphalted oil supercritical recovery tower is used as the high-temperature solvent in the settling section.

[0047] Preferably, the volume ratio of the total amount of high-temperature solvent added in the sedimentation section of step (2) to the feedstock oil is 3:1 to 8:1, for example 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 4:1 to 6:1.

[0048] Preferably, in step (2), the amount of high-temperature solvent added to the sedimentation section from each high-temperature solvent feed port of each sedimentation section increases sequentially from bottom to top, and the temperature gradient in the sedimentation section is controlled by controlling the amount of solvent added at each feed port.

[0049] Preferably, the temperature gradient in the sedimentation section of step (2) is 2 to 6°C, for example, 2°C, 2.5°C, 3°C, 3.5°C, 4°C, 4.5°C, 5°C, 5.5°C or 6°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In the present invention, when the high-temperature solvent in the sedimentation section is added from different feed ports, the amount added increases from bottom to top, so that the temperature of the extracted light components also gradually increases, which helps to ensure that the extracted light components are evenly heated and heated. The selection of the temperature gradient is related to the actual flow rate of the light components and the high-temperature solvent in the sedimentation section.

[0051] As a preferred technical solution of the present invention, the operating pressure of the sedimentation section in step (2) is 2.0 to 6.0 MPa, for example, 2.0 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, 4.0 MPa, 4.5 MPa, 5.0 MPa, 5.5 MPa or 6.0 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] Preferably, the residence time of the sedimentation section in step (2) is 20 to 50 min, for example, 20 min, 25 min, 30 min, 35 min, 40 min or 50 min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 25 to 35 min.

[0053] Preferably, the temperature at the top of the extraction tower in step (2) is 60-150°C, for example, 60°C, 70°C, 80°C, 100°C, 120°C, 140°C or 150°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] Preferably, the deasphalted oil in step (2) is obtained by heating the components extracted from the top of the tower, recovering the supercritical solvent and evaporating the solvent by steam stripping, wherein water vapor is used as the stripping gas.

[0055] Preferably, the yield of the deasphalted oil in step (2) is 20 to 62 wt%, for example, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt% or 62 wt%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. Compared with the conventional solvent deasphalting process, the yield of deasphalted oil can be increased by 3 to 5 wt%.

[0056] As a preferred technical solution of the present invention, the heavy component in step (3) includes heavy colloids and asphaltenes.

[0057] Preferably, the bottom temperature of the extraction tower in step (3) is 40-140°C, for example, 40°C, 50°C, 60°C, 80°C, 100°C, 120°C or 140°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] (1) The present invention uses an extraction tower for solvent deasphalting, and improves on the original division of the extraction section and the settling section. The extraction section is designed as a whole, and the temperature is kept basically consistent, so as to dissolve the soluble components in the crude oil to the maximum extent, reduce the volume of the extraction section, and thus reduce backmixing during the extraction process;

[0060] (2) The present invention sets a plurality of high-temperature solvent feed ports in the settling section to replace the setting of an external heat exchange pipe, thereby ensuring uniform temperature distribution in the settling section, uniformly heating the oil product coming up from the lower part of the extraction tower, reducing the loss of deasphalted oil caused by local overheating, and improving the yield of deasphalted oil;

[0061] (3) The extraction tower of the present invention has a simple structure, significant improvement effect and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the structure of a solvent deasphalting extraction tower provided in Example 1 of the present invention;

[0063] Figure 2 It is a schematic structural diagram of a solvent deasphalting extraction tower provided in Comparative Example 1 of the present invention;

[0064] Among them, 1-extraction section, 2-sedimentation section, 3-feed distributor. DETAILED DESCRIPTION

[0065] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention is further described in detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0066] The following are typical but non-limiting embodiments of the present invention:

[0067] Embodiment 1:

[0068] This embodiment provides a solvent deasphalting extraction tower. The structural schematic diagram of the extraction tower is as follows: Figure 1 As shown, it includes two parts, an extraction section 1 and a sedimentation section 2. The extraction section 1 is located below the sedimentation section 2. A crude oil feed port is provided on the side wall of the tower body between the extraction section 1 and the sedimentation section 2. An extraction section solvent feed port is provided below the extraction section 1. Three sedimentation section high-temperature solvent feed ports are evenly arranged on the side wall of the sedimentation section 2 along the axial direction.

[0069] The extraction tower is a packed tower, and packing layers are provided in both the extraction section 1 and the sedimentation section 2.

[0070] The packing layer in the extraction section 1 is arranged as a whole.

[0071] The packing layers in the sedimentation section 2 are arranged at intervals, and the positions of the intervals correspond to the positions of the high-temperature solvent feed ports of the sedimentation section.

[0072] The type of the packing is grid structured packing.

[0073] The bottom of the extraction tower is a heavy phase settling zone, which is provided with a de-oiled asphalt outlet.

[0074] A deasphalted oil outlet is provided at the top of the extraction tower.

[0075] The number of the high-temperature solvent feed inlets in the settling section is 3, and the high-temperature solvent feed inlets in the settling section are located on the same axis of the side wall of the tower body and are evenly arranged.

[0076] A feed distributor 3 is provided at the position of the high-temperature solvent feed port of each settling section, and a packing layer is provided above each feed distributor 3 .

[0077] Embodiment 2:

[0078] The present embodiment provides a solvent deasphalting extraction tower, which includes an extraction section 1 and a sedimentation section 2. The extraction section 1 is located below the sedimentation section 2. A crude oil feed port is provided on the side wall of the tower body between the extraction section 1 and the sedimentation section 2. An extraction section solvent feed port is provided below the extraction section 1. Four sedimentation section high-temperature solvent feed ports are evenly arranged on the side wall of the sedimentation section 2 along the axial direction.

[0079] The extraction tower is a packed tower, and packing layers are provided in both the extraction section 1 and the sedimentation section 2.

[0080] The packing layer in the extraction section 1 is arranged as a whole.

[0081] The packing layers in the sedimentation section 2 are arranged at intervals, and the positions of the intervals correspond to the positions of the high-temperature solvent feed ports of the sedimentation section.

[0082] The type of packing is Raschig ring random packing.

[0083] The bottom of the extraction tower is a heavy phase settling zone, which is provided with a de-oiled asphalt outlet.

[0084] A deasphalted oil outlet is provided at the top of the extraction tower.

[0085] The number of the high-temperature solvent feed inlets in the settling section is 4, and the high-temperature solvent feed inlets in the settling section are located on the same axis of the side wall of the tower body and are evenly arranged.

[0086] A feed distributor 3 is provided at the position of the high-temperature solvent feed port of each settling section, and a packing layer is provided above each feed distributor 3 .

[0087] Embodiment 3:

[0088] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0089] (1) adding a feedstock oil and a diluent solvent to an extraction tower after mixing, wherein the feedstock oil is Qinhuangdao vacuum residue oil, and its properties are shown in Table 1, wherein the diluent solvent is propane, and the volume ratio of the diluent solvent to the feedstock oil is 0.5:1, and the feedstock oil and the diluent solvent are added at a temperature of 58° C., and are in countercurrent contact with the extraction section solvent added to the bottom of the extraction tower, wherein the extraction section solvent is propane, and the volume ratio of the diluent solvent to the feedstock oil is 1.5:1, and the addition temperature is 58° C.; the temperature of the extraction section is kept consistent from top to bottom, and is the same as the addition temperature of the feedstock oil, which is 58° C., the operating pressure is 4.0 MPa, and the residence time is 20 min, thereby achieving preliminary separation of light and heavy components, wherein the light component includes saturated components, aromatic components, and light colloids;

[0090] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the settling section high-temperature solvent added to the settling section. The settling section is provided with three feed ports for the settling section high-temperature solvent. The settling section high-temperature solvent is propane recovered by supercritical reaction. The volume ratios of the solvent added from the feed ports to the crude oil are 0.8:1, 1.2:1 and 2:1 respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, which are 60° C., 65° C. and 70° C. respectively. The operating pressure of the settling section is 4.0 MPa, and the residence time is 30 min. The component extracted from the top of the extraction tower is heated for supercritical reaction recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 75° C.;

[0091] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 58°C.

[0092] Embodiment 4:

[0093] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0094] (1) The raw oil and the diluent solvent are mixed and added to the extraction tower. The raw oil is Suizhong vacuum residue oil, and its properties are shown in Table 1. The diluent solvent is propane. The volume ratio of the diluent solvent to the raw oil is 0.5:1. The addition temperature of the raw oil and the diluent solvent after mixing is 58° C., and the extraction stage solvent is added to the bottom of the extraction tower in countercurrent contact. The extraction stage solvent is propane, and the volume ratio of the diluent solvent to the raw oil is 2.5:1. The addition temperature is 58° C.; the temperature of the extraction stage is consistent from top to bottom, which is the same as the addition temperature of the raw oil, both of which are 58° C. The operating pressure is 2.0 MPa, and the residence time is 30 min, so as to achieve the preliminary separation of light and heavy components, and the light components include saturated components, aromatic components and light colloids;

[0095] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the settling section high-temperature solvent added to the settling section. The settling section is provided with three feed ports for the settling section high-temperature solvent. The settling section high-temperature solvent is propane recovered by supercritical reaction. The volume ratios of the solvent added from the feed ports to the crude oil from bottom to top are 1:1, 1.3:1 and 1.5:1, respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, and are 65° C., 70° C. and 75° C., respectively. The operating pressure of the settling section is 2.0 MPa, and the residence time is 45 min. The component extracted from the top of the extraction tower is heated for supercritical reaction recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 80° C.;

[0096] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 58°C.

[0097] Embodiment 5:

[0098] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0099] (1) adding a feedstock oil and a diluent solvent to an extraction tower after mixing, wherein the feedstock oil is Qinhuangdao vacuum residue oil, and its properties are shown in Table 1, the diluent solvent is butane, and the volume ratio of the diluent solvent to the feedstock oil is 0.4:1, and the feedstock oil and the diluent solvent are added at a temperature of 137° C., and are in countercurrent contact with the extraction section solvent added to the bottom of the extraction tower, wherein the extraction section solvent is butane, and the volume ratio of the diluent solvent to the feedstock oil is 1.8:1, and the addition temperature is 120° C.; the temperature of the extraction section is kept consistent from top to bottom, and is the same as the addition temperature of the feedstock oil, both of which are 137° C., the operating pressure is 5.0 MPa, and the residence time is 15 min, thereby achieving preliminary separation of light and heavy components, wherein the light component includes saturated components, aromatic components, and light colloids;

[0100] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the settling section high-temperature solvent added to the settling section. The settling section is provided with three feed ports for the settling section high-temperature solvent. The settling section high-temperature solvent is butane recovered by supercritical reaction. The volume ratios of the solvent added from the feed ports to the crude oil are 0.6:1, 1:1 and 2:1 respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, and are 140° C., 143° C. and 145° C. respectively. The operating pressure of the settling section is 5.0 MPa, and the residence time is 35 min. The component extracted from the top of the extraction tower is heated for supercritical reaction recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 147° C.;

[0101] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 137°C.

[0102] Embodiment 6:

[0103] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0104] (1) adding a feedstock oil and a diluent solvent to an extraction tower after mixing, wherein the feedstock oil is Caofeidian vacuum residue oil, and its properties are shown in Table 1, the diluent solvent is butane, and the volume ratio of the diluent solvent to the feedstock oil is 0.5:1. The feedstock oil and the diluent solvent are added at a temperature of 138° C. after mixing, and are in countercurrent contact with the extraction section solvent added to the bottom of the extraction tower, wherein the extraction section solvent is butane, and the volume ratio of the diluent solvent to the feedstock oil is 1:1, and the addition temperature is 130° C.; the temperature of the extraction section is kept consistent from top to bottom, which is the same as the addition temperature of the feedstock oil, both of which are 138° C., the operating pressure is 3.0 MPa, and the residence time is 10 min, thereby achieving preliminary separation of light and heavy components, wherein the light component includes saturated components, aromatic components, and light colloids;

[0105] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the settling section high-temperature solvent added to the settling section. The settling section is provided with three feed ports for the settling section high-temperature solvent. The settling section high-temperature solvent is butane recovered by supercritical reaction. The volume ratios of the solvent added from the feed ports to the crude oil from bottom to top are 1:1, 1.4:1 and 2:1, respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, and are 140° C., 143° C. and 146° C., respectively. The operating pressure of the settling section is 3.0 MPa, and the residence time is 20 min. The component extracted from the top of the extraction tower is heated for supercritical reaction recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 148° C.;

[0106] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 138°C.

[0107] Embodiment 7:

[0108] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0109] (1) adding a feedstock oil and a diluent solvent to an extraction tower after mixing, wherein the feedstock oil is Qinhuangdao vacuum residue oil, and its properties are shown in Table 1; the diluent solvent is a propane / butane mixture, and its proportion is 25:75 (wt%); the volume ratio of the diluent solvent to the feedstock oil is 0.6:1; the feedstock oil and the diluent solvent are added at a temperature of 105° C. after mixing, and are in countercurrent contact with the extraction section solvent added to the bottom of the extraction tower; the extraction section solvent is a propane / butane mixture, and its volume ratio to the feedstock oil is 1:1, and its addition temperature is 105° C.; the temperature of the extraction section is kept consistent from top to bottom, and is the same as the addition temperature of the feedstock oil, both of which are 105° C.; the operating pressure is 6.0 MPa, and the residence time is 10 min, so as to achieve preliminary separation of light and heavy components, and the light components include saturated components, aromatic components and light colloids;

[0110] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the settling section high-temperature solvent added to the settling section. The settling section is provided with three feed ports for the settling section high-temperature solvent. The settling section high-temperature solvent is a propane / butane mixture recovered supercritically. The volume ratios of the solvent added from the feed ports to the crude oil are 1:1, 1.5:1 and 2:1, respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, which are 108° C., 111° C. and 114° C., respectively. The operating pressure of the settling section is 6.0 MPa, and the residence time is 20 min. The component extracted from the top of the extraction tower is heated for supercritical recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 115° C.;

[0111] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 105°C.

[0112] Embodiment 8:

[0113] This embodiment provides a method for solvent deasphalting, which is carried out using the extraction tower in Example 1 and includes the following steps:

[0114] (1) adding a feedstock oil and a diluent solvent to an extraction tower after mixing, wherein the feedstock oil is Qinhuangdao vacuum residue oil, and its properties are shown in Table 1; the diluent solvent is a propane / butane mixture, and its proportion is 50:50 (wt%); the volume ratio of the diluent solvent to the feedstock oil is 0.6:1; the feedstock oil and the diluent solvent are added at a temperature of 85°C after mixing, and are in countercurrent contact with the extraction section solvent added to the bottom of the extraction tower; the extraction section solvent is a propane / butane mixture, and its volume ratio to the feedstock oil is 1:1, and its addition temperature is 95°C; the temperature of the extraction section is kept consistent from top to bottom, and is the same as the addition temperature of the feedstock oil, both of which are 95°C; the operating pressure is 6.0 MPa, and the residence time is 10 min, so as to achieve preliminary separation of light and heavy components, and the light components include saturated components, aromatic components and light colloids;

[0115] (2) the light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the high-temperature solvent of the settling section added to the settling section. The settling section is provided with three feed ports for the high-temperature solvent of the settling section. The high-temperature solvent of the settling section is a propane / butane mixture recovered supercritically. The volume ratios of the solvent added from the feed ports to the crude oil from bottom to top are 1:1, 1.5:1 and 2:1, respectively. The temperature gradient in the settling section increases from bottom to top according to the position of the feed ports, and is 88° C., 91° C. and 94° C., respectively. The operating pressure of the settling section is 6.0 MPa, and the residence time is 20 min. The component extracted from the top of the extraction tower is heated for supercritical recovery, and then the solvent is evaporated by steam stripping to obtain deasphalted oil. The temperature at the top of the extraction tower is 95° C.;

[0116] (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom. The heavy component includes heavy colloid and asphaltene. Deoiled asphalt is extracted from the bottom of the extraction tower. The bottom temperature of the extraction tower is 85°C.

[0117] Table 1 Properties of the vacuum residues described in Examples 3-8

[0118]

[0119]

[0120] Comparative Example 1:

[0121] This comparative example provides a solvent deasphalting extraction tower, the structural schematic diagram of which is as follows Figure 2 As shown, it includes two parts, an extraction section 1 and a sedimentation section 2. The extraction section 1 is located below the sedimentation section 2. A crude oil feed port is provided on the side wall of the tower body between the extraction section 1 and the sedimentation section 2. An extraction section solvent feed port is provided below the extraction section 1. A heat exchange pipe is provided in the sedimentation section 2, and heat transfer oil is passed through the heat exchange pipe.

[0122] The extraction tower is a packed tower, and packing layers are provided in the extraction section 1 and the sedimentation section 2, and the type of the packing is grid structured packing.

[0123] The bottom of the extraction tower is a heavy phase settling zone, which is provided with a de-oiled asphalt outlet.

[0124] A deasphalted oil outlet is provided at the top of the extraction tower.

[0125] Comparative Example 2:

[0126] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 3, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent in the settling section, but instead uses indirect heating with heat transfer oil. It is only disclosed that the bottom temperature of the extraction tower is 58°C and the top temperature is 75°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 3.

[0127] Comparative Example 3:

[0128] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 4, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent into the settling section, but instead uses steam for indirect heating. It is only disclosed that the bottom temperature of the extraction tower is 58°C and the top temperature is 80°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 4.

[0129] Comparative Example 4:

[0130] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 5, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent in the settling section, but instead uses indirect heating with heat transfer oil. It is only disclosed that the bottom temperature of the extraction tower is 137°C and the top temperature is 147°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 5.

[0131] Comparative Example 5:

[0132] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 6, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent into the settling section, but instead uses steam for indirect heating. It is only disclosed that the bottom temperature of the extraction tower is 138°C and the top temperature is 148°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 6.

[0133] Comparative Example 6:

[0134] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 7, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent into the settling section, but instead uses steam for indirect heating. It is only disclosed that the bottom temperature of the extraction tower is 105°C and the top temperature is 115°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 7.

[0135] Comparative Example 7:

[0136] This comparative example provides a method for solvent deasphalting, which is carried out using the extraction tower in comparative example 1. The method refers to the method in Example 8, with the only difference being that step (1) does not disclose maintaining a consistent temperature in the extraction section, and step (2) does not disclose the introduction of a high-temperature solvent into the settling section, but instead uses steam for indirect heating. It is only disclosed that the bottom temperature of the extraction tower is 85°C and the top temperature is 95°C, and the amount of solvent added to the extraction section is the total amount of solvent added to the extraction section and the settling section in Example 8.

[0137] The yields of the deasphalted oil obtained in Examples 3-8 and Comparative Examples 2-7 were calculated, and the properties of the deasphalted oil were detected. Due to the different solvents used, Examples 3-4 and Comparative Examples 2-3 used propane as solvent for deasphalting, and the results are shown in Table 2. Examples 5-6 and Comparative Examples 4-5 used butane as solvent for deasphalting, and the results are shown in Table 3. Examples 7-8 and Comparative Examples 6-7 used a mixture of propane and butane as solvent for deasphalting, and the results are shown in Table 4.

[0138] Table 2 Yield and properties of deasphalted oil in Examples 3-4 and Comparative Examples 2-3

[0139]

[0140]

[0141] Table 3 Yield and properties of deasphalted oil in Examples 5-6 and Comparative Examples 4-5

[0142] project Example 5 Comparative Example 4 Example 6 Comparative Example 5 Yield, wt% 61.74 57.35 24.5 21.0 <![CDATA[Density (20 °C), g / cm 3 > 0.9421 0.9455 0.9253 0.9296 <![CDATA[Kinematic viscosity at 80 °C, mm 2 / s]]> 88.45 90.56 69.75 71.24 <![CDATA[Kinematic viscosity at 100 °C, mm 2 / s]]> 41.65 42.73 32.88 33.56 Carbon residue,% 1.03 1.10 1.12 1.20 S，％ 0.22 0.23 0.18 0.19 N, μg / g 2165 2272 2598 2646 Refractive index at 20℃ 1.5153 1.5165 1.5173 1.5182

[0143] Table 4 Yield and properties of deasphalted oil in Examples 7-8 and Comparative Examples 6-7

[0144]

[0145]

[0146] As can be seen from Tables 2-4, by using the solvent deasphalting extraction tower in Examples 3-8 to deasphalt vacuum residue oil, the yield of the deasphalted oil obtained can be increased by more than 3.0% compared with the conventional extraction tower in the corresponding comparative example, and can reach up to about 4.4%; the basic properties of the deasphalted oil are better than those of the deasphalted oil obtained in the comparative example, especially the residual carbon content is reduced.

[0147] It can be seen from the above embodiments and comparative examples that the present invention uses an extraction tower for solvent deasphalting, and improves on the basis of the original division of the extraction section and the settling section. The extraction section is designed as a whole, and the temperature is kept basically consistent, so as to dissolve the soluble components in the raw oil to the maximum extent, reduce the volume of the extraction section, and thus reduce the back mixing during the extraction process; the present invention arranges a plurality of high-temperature solvent feed ports in the settling section to replace the arrangement of the external heat exchange pipe, so as to ensure that the temperature distribution of the settling section is uniform, and the oil product coming up from the lower part of the extraction tower is uniformly heated, so as to reduce the loss of deasphalted oil caused by local overheating, and improve the yield of deasphalted oil; the extraction tower has a simple structure, a significant improvement effect, and a low cost.

[0148] The applicant declares that the present invention uses the above embodiments to illustrate the detailed devices and methods of the present invention, but the present invention is not limited to the above detailed devices and methods, that is, it does not mean that the present invention must rely on the above detailed devices and methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the device of the present invention, addition of auxiliary devices, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for solvent deasphalting using a solvent deasphalting extraction tower, characterized in that: The extraction tower comprises an extraction section and a settling section. The extraction section is located below the settling section. A feed inlet for crude oil is provided on the side wall of the tower body between the extraction section and the settling section. A feed inlet for extraction section solvent is provided below the extraction section. At least two feed inlets for high-temperature solvent of the settling section are evenly provided on the side wall of the settling section along the axial direction. The extraction tower is a packed tower, and packing layers are provided in both the extraction section and the sedimentation section; The packing layers in the settling section are arranged at intervals, and the positions of the intervals correspond to the positions of the high-temperature solvent feed ports of the settling section; The bottom of the extraction tower is a heavy phase settling zone, and is provided with a de-oiled asphalt outlet; The top of the extraction tower is provided with a deasphalted oil outlet; The method for performing solvent deasphalting in the solvent deasphalting extraction tower comprises the following steps: (1) The crude oil and the diluent solvent are mixed and added to the extraction tower, where they are countercurrently contacted with the extraction section solvent added at the bottom of the extraction tower to achieve preliminary separation of light and heavy components; (2) The light component obtained in step (1) enters the settling section of the extraction tower, and conducts mass and heat transfer with the high-temperature solvent added to the settling section. The temperature of the settling section increases gradually from bottom to top, and deasphalted oil is extracted from the top of the extraction tower; (3) The heavy component obtained in step (1) enters the heavy phase settling zone at the bottom, and the deoiled asphalt is extracted from the bottom of the extraction tower; Among them, the operations of step (2) and step (3) are performed in no particular order; In step (2), the amount of the high-temperature solvent added to the sedimentation section from the high-temperature solvent feed port of each sedimentation section increases from bottom to top; The temperature gradient in the sedimentation section of step (2) is 2-6°C.

2. The method according to claim 1, characterized in that The packing layer in the extraction section is arranged integrally.

3. The method according to claim 1, characterized in that The types of packing include structured packing or random packing.

4. The method according to claim 3, characterized in that The structured packing includes corrugated packing and / or grid packing, and the random packing includes any one of Raschig rings, Pall rings, conjugate rings, saddle rings or stepped rings, or a combination of at least two of them.

5. The method according to claim 1, characterized in that: The number of the high-temperature solvent feed inlets of the settling section is 2 to 4, and the high-temperature solvent feed inlets of the settling section are located on the same axis of the side wall of the tower body and are evenly arranged.

6. The method according to claim 1, characterized in that A feed distributor is provided at the position of the high-temperature solvent feed port of each settling section, and a packing layer is provided above each feed distributor.

7. The method according to claim 1, characterized in that The type of the raw oil in step (1) is low-quality heavy oil.

8. The method according to claim 1, characterized in that The type of the feedstock oil is any one of vacuum residue oil, atmospheric residue oil, heavy oil or catalytic oil slurry, or a combination of at least two of them.

9. The method according to claim 1, characterized in that: The dilution solvent in step (1) includes propane and / or butane.

10. The method according to claim 1, characterized in that The volume ratio of the dilution solvent to the raw material oil in step (1) is 0.4:1 to 0.6:

1.

11. The method according to claim 1, characterized in that: The temperature at which the raw material oil and the diluent solvent are added after mixing in step (1) is 40-140°C.

12. The method according to claim 1, characterized in that The extraction solvent in step (1) includes propane and / or butane.

13. The method according to claim 1, characterized in that The volume ratio of the solvent to the crude oil in the extraction stage of step (1) is 1:1 to 3:

1.

14. The method according to claim 1, characterized in that The temperature for adding the solvent in the extraction stage of step (1) is 40-140°C.

15. The method according to claim 1, characterized in that The temperature of the extraction section in step (1) is kept consistent from top to bottom and is the same as the addition temperature of the feedstock oil.

16. The method according to claim 1, characterized in that The operating pressure of the extraction section in step (1) is 2.0-6.0 MPa.

17. The method according to claim 1, characterized in that The residence time of the extraction section in step (1) is 10 to 40 minutes.

18. The method according to claim 1, characterized in that The residence time of the extraction section in step (1) is 15 to 20 minutes.

19. The method according to claim 1, characterized in that The light components dissolved in the extraction solvent in step (1) include saturated components, aromatic components and light colloids.

20. The method according to claim 1, characterized in that In step (2), the sedimentation section is provided with 2 to 4 sedimentation section high-temperature solvent feed ports, into which the sedimentation section high-temperature solvent is added respectively.

21. The method according to claim 1, characterized in that The high-temperature solvent in the settling section of step (2) includes propane and / or butane.

22. The method according to claim 1, characterized in that The high-temperature solvent in the sedimentation stage is the high-temperature solvent obtained after supercritical recovery of deasphalted oil, and the temperature thereof is 220-280°C.

23. The method according to claim 1, characterized in that The volume ratio of the total amount of high-temperature solvent added in the sedimentation section of step (2) to the raw oil is 3:1 to 8:

1.

24. The method according to claim 23, characterized in that The volume ratio of the total amount of high-temperature solvent added in the sedimentation section of step (2) to the raw oil is 4:1 to 6:

1.

25. The method according to claim 1, characterized in that The operating pressure of the sedimentation section in step (2) is 2.0-6.0 MPa.

26. The method according to claim 1, characterized in that The residence time of the sedimentation section in step (2) is 20 to 50 minutes.

27. The method according to claim 26, characterized in that The residence time of the sedimentation section in step (2) is 25 to 35 minutes.

28. The method according to claim 1, characterized in that The temperature at the top of the extraction tower in step (2) is 60-150°C.

29. The method according to claim 1, characterized in that The deasphalted oil in step (2) is obtained by heating the components extracted from the top of the tower, recovering the supercritical solvent and evaporating the solvent by steam stripping.

30. The method according to claim 1, characterized in that The yield of the deasphalted oil in step (2) is 20-62 wt%.

31. The method according to claim 1, characterized in that The heavy component in step (3) includes heavy colloids and asphaltenes.

32. The method according to claim 1, characterized in that The bottom temperature of the extraction tower in step (3) is 40-140°C.

Images