A system and method for treating aged oil by coupling thermal hydrolysis with extraction

Abstract

The present application relates to a kind of hydrolysis-extraction coupling processing aging oil system and method, system includes preheating tank, hydrothermal reactor, sequentially connected flash tank, heat exchanger and oil-water separator and three-phase centrifuge.Aging oil mixture material is preheated after entering preheating tank and obtains preheated material;Preheated material enters hydrothermal reactor and obtains hydrothermal reaction oil slurry;Hydrothermal reaction oil slurry enters flash tank, and flash separation is obtained by flash oil gas and flash remaining oil slurry;Flash oil gas is obtained by heat exchanger, oil-water separator, circulating extraction agent, recovery extraction agent, sewage and incondensable gas, circulating extraction agent is transported to preheating tank;Flash remaining oil slurry is transported to three-phase centrifuge and centrifuged.By hydrolysis-flash effect, the flowability of aging oil system is improved, the extraction effect is strengthened, and the addition proportion of extraction agent is reduced;And all processes are completed in closed system, reduce the volatilization of oil gas and extraction agent, reduce the pollution generated by oil gas dispersion in disposal process.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical environmental protection technology, and particularly relates to a hot hydrolysis-extraction coupled system and method for treating aged oil. BACKGROUND

[0002] Aged oil is a complex and stable water-containing slurry or oil-containing emulsion produced in the process of crude oil gathering, storage, sewage treatment and petroleum and petrochemical production. The aged oil is stable in state, and it is difficult for the existing crude oil treatment system to treat the aged oil. Not only does the aged oil occupy a large amount of storage space, but also affects the quality of the exported oil, interferes with the operation of the electric dehydration device, causes equipment corrosion and structure, and is toxic and flammable. Direct discharge will pollute the environment. At present, most enterprises combine their own business characteristics and return the aged oil to the crude oil for export or return it for disposal. However, due to product quality control requirements, the treatment method has limited absorption, and how to economically and efficiently treat the aged oil has become an urgent problem for the petroleum industry.

[0003] At present, the reported methods for treating aged oil mainly include quality adjustment centrifugal separation, chemical hot washing, chemical oxidation and combined process. The key to the treatment method is how to demulsify and destabilize to accelerate the separation of water and oil. CN110950513B provides a method for treating bottom sludge by using surfactant pretreatment-hydrothermal oxidation-thermal cracking coupling. In the reported examples, the residue organic matter content of the sludge containing 79% water and 18% oil is less than 1% after treatment by the method. CN110484295A provides an aged oil recovery treatment process. The solid-liquid separator and the oil-water separator are used in combination to separate the oil-water mixture after solid-liquid separation, and an ultrasonic cleaning device and a high-pressure flushing device are additionally provided in the oil-water separator. The ultrasonic cavitation effect, mechanical stirring effect and thermal effect are used to improve the demulsification efficiency and demulsification dehydration amount. CN113680106A provides an electron beam irradiation treatment process for aged oil. The method changes the charge distribution of the molecular group interface that reaches charge balance in the aged oil from a micro perspective, and makes the related water molecules and the molecules that can react on the corresponding energy level react to become charged particles without adding chemical reagents, thereby rapidly destabilizing and achieving demulsification. However, the aged oil treatment methods described in the above documents require the addition of a large amount of surfactants and other reagents, which adversely affect the quality of the recovered oil.

[0004] In addition, due to the need for efficient recovery of mineral oil, some studies use extraction methods for treatment, based on the principle of like dissolves like, by reducing the strength of the oil-water interface film, promoting the separate aggregation of oil and water droplets, and realizing the separation of oil, water and mud. For example, CN113233725A discloses a device for treating oil-containing sludge by reselection and extraction coupling, which recovers part of the oil by chemical water washing and air flotation method, and further deoils by using multi-stage reverse extraction. The residue after deoiling can be granulated and solidified. CN111777293A discloses a method for extracting oil sludge using liquid dimethyl ether. By adjusting the system pressure, the phase change of liquid and gaseous dimethyl ether is realized. Extraction is carried out under liquid conditions, and rapid separation of the extractant is completed under gaseous conditions, realizing the recovery of hydrocarbons and the removal of water in the oil sludge. However, pure extraction method generally needs more than the amount of raw material of extractant, which has high economic cost, and solvent recovery is difficult, which may cause secondary pollution risk to the subsequent material entrainment. SUMMARY

[0005] To solve the problems of difficult dehydration and impurity removal of aged oil, poor quality, large storage, and influence on normal operation of the system, the present application provides a hot hydrolysis-extraction coupled treatment system for aged oil, which comprises a pretreatment unit, a hydrothermal reaction unit, an extractant recovery unit and a centrifugal separation unit.

[0006] The pretreatment unit comprises a preheating tank, and the hydrothermal reaction unit comprises a hydrothermal reaction kettle; the extractant recovery unit comprises a flash tank, a heat exchanger and an oil-water separator connected in sequence; and the centrifugal separation unit comprises a three-phase centrifugal machine; wherein,

[0007] The outlet of the pretreatment unit is connected with the inlet of the hydrothermal reaction unit, and the outlet of the hydrothermal reaction unit is connected with the inlet of the extractant recovery unit.

[0008] One outlet of the extractant recovery unit is connected with the inlet of the pretreatment unit, and the other outlet of the extractant recovery unit is connected with the inlet of the centrifugal separation unit.

[0009] Further, the preheating tank is provided with three inlets and one outlet; wherein,

[0010] The first inlet of the preheating tank is used for conveying aged oil raw materials; the second inlet of the preheating tank is used for conveying supplementary extractant; and the third inlet of the preheating tank is used for conveying recycled extractant recovered by the extractant recovery unit.

[0011] The outlet of the preheating tank is used for conveying the preheated materials to the hydrothermal reaction kettle.

[0012] Further, the flash tank is provided with two outlets, the first outlet of the flash tank is connected with the inlet of the heat exchanger, and the second outlet of the flash tank is connected with the three-phase centrifugal machine; the inlet of the flash tank is connected with the outlet of the hydrothermal reaction kettle.

[0013] Further, the three-phase centrifuge is provided with three outlets, and the three outlets of the three-phase centrifuge are respectively used for outputting a centrifugal oil phase, a centrifugal water phase and a centrifugal mud.

[0014] Further, the oil-water separator is provided with two inlets and four outlets, wherein,

[0015] The first inlet of the oil-water separator is connected with the outlet of the heat exchanger, and the second inlet of the oil-water separator is connected with an external pipeline for conveying the demulsifier.

[0016] The first outlet of the oil-water separator is connected with the tail gas purification system and is used for conveying non-condensable gas generated in the oil-water separator to the tail gas purification system, the second outlet of the oil-water separator is connected with the sewage treatment system and is used for conveying an oil-water mixture generated in the oil-water separator to the sewage treatment system, the third outlet of the oil-water separator is connected with the storage device and is used for conveying the upper layer of the recovered extractant generated in the oil-water separator to the storage device, and the fourth outlet of the oil-water separator is connected with the preheating tank and is used for conveying the circulating extractant to the preheating tank.

[0017] The application further provides a method for treating aged oil by using the above-mentioned system, and the method comprises the following steps: after the aged oil mixture is preheated in the preheating tank, preheated material is obtained; the preheated material is input into the hydrothermal reaction kettle, and after hydrothermal reaction treatment, hydrothermal reaction oil slurry is obtained; the hydrothermal reaction oil slurry is input into the flash tank, and after flash separation, flash oil gas and flash residual oil slurry are obtained; the flash oil gas is input into the heat exchanger and the oil-water separator, and circulating extractant, recovered extractant, sewage and non-condensable gas are obtained, and the circulating extractant is conveyed to the preheating tank; and the flash residual oil slurry is conveyed to the three-phase centrifuge for centrifugal separation.

[0018] Further, the preheating of the aged oil mixture in the preheating tank comprises the following steps:

[0019] The aged oil raw material is conveyed to the preheating tank through the first inlet of the preheating tank, heated to 65-85 DEG C, mixed with the mixed extractant, and then preheated material is obtained.

[0020] Further, the preheating of the preheated material in the hydrothermal reaction kettle comprises the following steps:

[0021] The preheated material is input into the hydrothermal reaction kettle, heated to 110-200 DEG C, and maintained at the final heating temperature for 15-40 min.

[0022] Further, the flash oil gas is input into the heat exchanger and the oil-water separator, and circulating extractant, recovered extractant, sewage and non-condensable gas are obtained, and the circulating extractant is conveyed to the preheating tank.

[0023] The flash oil gas is transported to the heat exchanger through the first outlet of the flash tank, and the cooled oil slurry is obtained after being cooled to 40-65 DEG C by circulating water in the heat exchanger;

[0024] The cooled oil slurry is transported to the oil-water separator through the first inlet of the oil-water separator, and the demulsifier is added through the second inlet of the oil-water separator, so that the circulating extraction agent, the recovered extraction agent, the sewage and the incondensable gas are obtained; the circulating extraction agent is transported to the preheating tank through the third outlet of the oil-water separator.

[0025] Further, the incondensable gas is transported to the tail gas purification system through the first outlet of the oil-water separator, and the sewage is transported to the sewage treatment system through the second outlet of the oil-water separator; the recovered extraction agent is transported to the storage device through the third outlet of the oil-water separator.

[0026] Further, the pressure in the flash tank is lower than 0.1 Mpa.

[0027] Further, the flash residual oil slurry is transported to the three-phase centrifuge through the second outlet of the flash tank, and the centrifugal separation water phase, the centrifugal mud and the centrifugal separation oil phase are obtained by centrifugal separation in the three-phase centrifuge and are transported to the back refining system.

[0028] Further, the mixed extraction agent is the supplementary extraction agent transported through the second inlet of the preheating tank and the circulating extraction agent transported through the third inlet of the preheating tank; the mass ratio of the mixed extraction agent to the aged oil raw material is 1:2-1:5.

[0029] The present application realizes the deflocculation and the dehydration of the aged oil and the recovery of the light oil by the thermal hydrolysis pretreatment, then the light oil is used as the extraction agent, the dispersion and the dissolution of the asphaltene and the colloid components in the heavy oil are promoted, the mechanical strength of the water-in-oil interface film is reduced, the coalescence of the internal water droplets is promoted, then the effective separation and the recovery of the oil are realized by the centrifugal separation, the purpose of the dehydration of the aged oil is realized, the recovered oil is pure, free of external agents and impurity pollution, and the quality is good. Meanwhile, the flowability of the aged oil system is improved, the extraction effect is strengthened, and the addition proportion of the extraction agent is reduced by the thermal hydrolysis-flash effect. In addition, all the processes of the present application are completed in a closed system, the volatilization of the oil gas and the extraction agent is reduced, and the pollution caused by the oil gas emission in the disposal process is reduced.

[0030] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a system for treating aged oil using a hot water hydrolysis-extraction coupling method according to an embodiment of the present invention;

[0033] Figure 2 This is a flowchart of a method for treating aged oil using a hot water hydrolysis-extraction coupling method in an embodiment of the present invention.

[0034] Attached reference numerals: 1. Preheating tank; 2. Hydrothermal reactor; 3. Flash tank; 4. Heat exchanger; 5. Oil-water separator; 6. Three-phase centrifuge;

[0035] 11. Aged oil raw material; 12. Supplemental extractant; 13. Preheated material; 21. Oil slurry after hydrothermal reaction; 31. Flash evaporation oil gas; 32. Residual oil slurry after flash evaporation; 41. Cooled oil slurry; 51. Demulsifier; 52. Non-condensable gas; 53. Wastewater; 54. Recovered extractant; 55. Circulating extractant; 61. Centrifugal separation of oil phase; 62. Centrifugal separation of aqueous phase; 63. Centrifugal sludge. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] A first aspect of the embodiments of the present invention, as follows: Figure 1 As shown, a hot water hydrolysis-extraction coupled treatment system for aged oil is provided. The system consists of a pretreatment unit, a hydrothermal reaction unit, an extractant recovery unit, and a centrifugal separation unit. The pretreatment unit includes a preheating tank 1, and the hydrothermal reaction unit includes a hydrothermal reactor 2. The extractant recovery unit includes a flash tank 3, a heat exchanger 4, and an oil-water separator 5 connected in sequence. The centrifugal separation unit includes a three-phase centrifuge 6.

[0038] The preheating tank 1 is provided with three inlets and one outlet; the first inlet of the preheating tank 1 is used for inputting the aging oil raw material 11 to be treated; the second inlet of the preheating tank 1 is used for inputting the supplementary extraction agent 12; the third inlet of the preheating tank 1 is used for inputting the recycled extraction agent 55 recovered by the extraction agent recovery unit; and the outlet of the preheating tank 1 is used for outputting the preheated material 13 to the hydrothermal reaction kettle 2.

[0039] The hydrothermal reaction kettle 2 is used for heating the preheated material 13, and obtaining the hydrothermal reaction oil slurry 21.

[0040] The flash tank 3 is provided with two outlets and one inlet, and the inlet of the flash tank 3 is connected with the outlet of the hydrothermal reaction kettle 2; the first outlet of the flash tank 3 is connected with the inlet of the heat exchanger 4, and is used for conveying the flash oil gas 31 to the heat exchanger 4; and the second outlet of the flash tank 3 is connected with the three-phase centrifuge 6, and is used for conveying the flash remaining oil slurry 32 to the three-phase centrifuge 6 through the inlet of the three-phase centrifuge 6.

[0041] The three-phase centrifuge 6 is also provided with three outlets, and the three outlets of the three-phase centrifuge 6 are respectively used for outputting the centrifugal separation oil phase 61, the centrifugal separation water phase 62 and the centrifugal mud 63.

[0042] The oil-water separator 5 is provided with two inlets and four outlets; the first inlet of the oil-water separator 5 is connected with the outlet of the heat exchanger 4; the second inlet of the oil-water separator 5 is connected with an external pipeline used for conveying the demulsifying agent 51; the first outlet of the oil-water separator 5 is connected with a tail gas purification system, and is used for conveying the non-condensable gas 52 generated in the oil-water separator 5 to the tail gas purification system; the second outlet of the oil-water separator 5 is connected with a sewage treatment system, and is used for conveying the lower layer sewage 53 of the condensed liquid phase in the oil-water separator 5 to the sewage treatment system; the third outlet of the oil-water separator 5 is respectively connected with a storage device and the preheating tank 1, and is used for conveying the upper layer recycled extraction agent 54 of the condensed liquid phase in the oil-water separator 5 to the storage device, and conveying the recycled extraction agent 55 to the preheating tank 1.

[0043] As shown in a second aspect of the embodiment of the present application, Figure 2 a hydrothermal extraction coupled method for treating aging oil is provided, which is completed by using the above system, and the method comprises the following steps: an aging oil mixture is preheated in the preheating tank 1 to obtain a preheated material 13; the preheated material 13 is input into the hydrothermal reaction kettle 2, and is treated by hydrothermal reaction to obtain a hydrothermal reaction oil slurry 21; the hydrothermal reaction oil slurry 21 is input into the flash tank 3, and is separated by the flash tank 3 to obtain flash oil gas 31 and flash remaining oil slurry 32; the flash oil gas 31 is input into the heat exchanger 4, and the recycled extraction agent 55, the recycled extraction agent 54, the sewage 53 and the non-condensable gas 52 are obtained by using the oil-water separator 5, and the recycled extraction agent 55 is conveyed to the preheating tank 1; and the flash remaining oil slurry 32 is input into the three-phase centrifuge 6 for centrifugal separation.

[0044] Specifically, the extractant is preferably a mixture of aromatic hydrocarbons (such as a mixture of catalytic reforming dimethylbenzene, toluene, etc.), a distillate oil such as light diesel oil, or a light oil obtained by flash separation of the raw material (such as a gasoline to light diesel oil fraction, mainly C6-C14 alkanes and C6-C8 aromatic hydrocarbons).

[0045] Specifically, the aged oil raw material 11 is heated to 65-85°C by an external heating source in the preheating tank 1 and is mixed with the supplemental extractant 12. Optimally, the preheating tank 1 is jacketed for heat exchange, and the heat source is low-pressure steam or flash oil gas 31.

[0046] The ratio of the mixed extractant to the aged oil raw material 11 is selected as 1:2-1:5 (mass ratio) according to the material; the mixed extractant includes the supplemental extractant 12 and the recycled extractant 55 delivered through the third inlet of the preheating tank 1. The preheated mixed extractant and the preheated material 13 enter the hydrothermal reaction kettle 2, which is heated by steam or the like, and the mixture is heated to 110-200°C in a sealed manner, the pressure in the hydrothermal reaction kettle 2 is controlled at 0.14-1.60 MPa (gauge pressure), and the final temperature is maintained for 15-40 min, to obtain the hydrothermally reacted oil slurry 21. This process can break the stable structure of the system, reduce the strength of the oil-water interface film, and enhance the extraction efficiency. The present application can also directly introduce steam into the hydrothermal reaction kettle 2 to achieve the functions of heating and stirring.

[0047] The flash tank 3 has sufficient volume space and can achieve rapid discharge of oil gas, maintaining the pressure at 0±0.10 MPa (gauge pressure). The hydrothermally reacted oil slurry 21 enters the flash tank 3 and rapidly expands in the space of the flash tank 3, achieving pressure reduction and temperature reduction, and the water and light oil (i.e., flash oil gas 31) enter the heat exchanger 4 and are cooled to obtain the cooled oil slurry 41. The cooled oil slurry 41 enters the oil-water separator 5, where a demulsifier is added, and is further separated into non-condensable gas 52, recovered extractant 54, and sewage 53. The other water and heavy oil (i.e., flash remaining oil slurry 32) at the bottom of the flash tank 3 are pumped by a delivery pump to the three-phase centrifuge 6 of the centrifugal separation unit. The flash remaining oil slurry 32 is centrifuged by the three-phase centrifuge 6 to obtain a centrifuged oil phase 61, a centrifuged water phase 62, and a centrifuged mud 63.

[0048] The process steps of the above-mentioned hydrothermal decomposition-extraction coupled treatment of aged oil method are described below through specific examples.

[0049] Example 1

[0050] The aged crude oil of a certain oilfield contains 11.3%±1.5% water, which is fed into the preheating tank 1 through the first inlet of the preheating tank 1 by the screw pump, heated to 80°C by the steam coil in the preheating tank 1, and mixed with the supplementary extractant 12 fed through the second inlet of the preheating tank 1 to obtain the preheated material 13. Initially, the supplementary extractant 12 containing mixed aromatic hydrocarbons is added to the preheating tank 1, and after the device is continuously and stably operated, the circulating extractant 55 fed through the third inlet of the preheating tank 1 is used as the main supplement. The mass ratio of the mixed extractant in the preheating tank 1 to the aged oil raw material 11 is 1:3, and the mass of the mixed extractant refers to the total mass of the supplementary extractant 12 and the circulating extractant 55.

[0051] Further, the preheated material 13 is fed into the hydrothermal reaction kettle 2 through the outlet of the preheating tank 1, heated to 200°C (the pressure in the hydrothermal reaction kettle 2 is about 1.60 MPa) by using the direct steam heat exchange method, and kept at this temperature for 15 min to obtain the hydrothermally reacted oil slurry 21.

[0052] After the constant temperature is ended, the hydrothermally reacted oil slurry 21 is discharged through the inlet of the flash tank 3, and through the subsequent condensation and oil gas purification system, the pressure of the flash tank 3 is controlled to be less than 0.10 MPa. The pressure of the hydrothermally reacted oil slurry 21 after entering the flash tank 3 is reduced, and the volume is rapidly expanded. The flash oil gas 31 is fed into the heat exchanger 4 through the first outlet of the flash tank 3, cooled to 65°C by using the cooling circulating water, and then fed into the oil-water separator 5 through the first inlet of the oil-water separator 5. The non-condensable gas 52 is fed into the subsequent tail gas purification system through the first outlet of the oil-water separator 5. The oil-water mixture is further separated and settled, and the separated sewage 53 is fed into the sewage treatment system through the second outlet of the oil-water separator 5. Part of the recovered extractant is fed into the storage facility as the recovered extractant 54 through the third outlet of the oil-water separator 5, and part of the recovered extractant is fed into the preheating tank 1 as the circulating extractant 55 through the fourth outlet of the oil-water separator 4. The flash remaining oil slurry 32 at the bottom of the flash tank 3 is fed into the three-phase centrifugal separator 6 through the second outlet of the flash tank 3 by the conveying system, and the centrifugal oil phase 61, the centrifugal water phase 62 and the centrifugal mud 63 are obtained by the action of the centrifugal force. The water content in the centrifugal oil phase 61 is less than 0.5%, which meets the requirement of the water content of the oil for external transportation.

[0053] Example 2

[0054] The aged oil from a refinery contains 8.8%±1.2% water, which is transported by a contaminated oil pump from a preheating tank 1 first inlet to the preheating tank 1, heated to 60°C by a flash oil gas 31 coil in the preheating tank 1, and mixed with a supplementary extractant 12 transported by the preheating tank 1 second inlet to obtain a preheated material 13. Initially, mixed xylene from a catalytic reforming unit is added to the preheating tank 1 as the supplementary extractant 12, and after the device is continuously and stably operated, the circulating extractant 55 transported by the preheating tank 1 third inlet is used as the main supplement. The mass ratio of the mixed extractant in the preheating tank 1 to the aged oil raw material 11 is 1:2, and the mass of the mixed extractant refers to the total mass of the supplementary extractant 12 and the circulating extractant 55.

[0055] Further, the preheated material 13 is transported from the preheating tank 1 outlet to a hydrothermal reaction kettle 2, adopts a steam direct heat exchange mode, is heated to 110°C in the hydrothermal reaction kettle 2 in a sealed manner (the pressure in the hydrothermal reaction kettle 2 is about 0.14 MPa), and is kept at a constant temperature for 40 min at this temperature to obtain a hydrothermal reaction oil slurry 21.

[0056] After the constant temperature ends, the hydrothermal reaction oil slurry 21 is discharged from the flash tank 3 inlet, and the pressure in the flash tank 3 is controlled to be <0.1 MPa. The pressure of the hydrothermal reaction oil slurry 21 after entering the flash tank 3 is reduced, and the volume is rapidly expanded. The flash oil gas 31 enters the heat exchanger 4 from the flash tank 3 first outlet, is cooled to 65°C by using cooling circulating water, and then enters the oil-water separator 5 from the oil-water separator 5 first inlet.

[0057] 50 ppm of a cationic demulsifier 51 is added from the oil-water separator 5 second inlet, the non-condensable gas 52 is transported from the oil-water separator 5 first outlet to a subsequent tail gas purification system, the oil-water mixture is further separated and settled, the separated sewage 53 is transported from the oil-water separator 5 second outlet to a sewage treatment system, and part of the recovered extractant is transported from the oil-water separator 5 third outlet to a storage facility as the recovered extractant 54, and part of the recovered extractant is transported from the oil-water separator fourth outlet to the preheating tank as the circulating extractant 55.

[0058] The flash remaining oil slurry 32 at the bottom of the flash tank 3 is transported from the flash tank second outlet to the three-phase centrifugal separator 6 by a conveying system, and the centrifugal oil phase 61, the centrifugal water phase 62 and the centrifugal mud 63 are obtained by the action of centrifugal force. The water content in the centrifugal oil phase 61 is <1%, and the centrifugal oil phase 61 is sent to a re-refining system.

[0059] The hydrothermal reaction-extraction coupling method for treating aged oil provided by the present application can realize efficient de-stabilization and refining of the aged oil, and reduce the use amount and consumption of the extractant. The extractant is preferably mixed aromatic hydrocarbon, light diesel oil or other distillate oil, or light oil obtained by flash separation of the raw material, and the extractant is recovered by using a vacuum flash method, which can greatly improve the quality of the recovered oil.

[0060] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood that modifications can be made to the foregoing embodiments, or additional implementations can be implemented, without departing from the spirit and scope of the inventive subject matter. Accordingly, the present application is not limited to the implementations described herein, but is intended to be defined by the claims set forth below, and equivalents thereof.

Claims

1. A method for coupled hot water hydrolysis-extraction treatment of aged oil, characterized in that, The method includes: The aged oil mixture is preheated in a preheating tank to obtain preheated material; the preheated material is then placed in a hydrothermal reactor and heated to 110-200°C, and maintained at the final heating temperature for 15-40 minutes, with the pressure inside the hydrothermal reactor controlled at 0.14-1.60 MPa. After hydrothermal reaction treatment, a hydrothermal reaction slurry is obtained. This slurry then enters a flash tank, where the pressure is below 0.1 MPa. Flash separation in the flash tank yields flash oil gas and residual flash oil slurry. The flash oil gas passes through a heat exchanger and an oil-water separator to obtain circulating extractant, recovered extractant, wastewater, and non-condensable gas. The circulating extractant is then sent to a preheating tank. The residual flash oil slurry is sent to a three-phase centrifuge for centrifugal separation. The aged oil mixture is preheated in a preheating tank to obtain preheated material, which includes: The aged oil raw material is conveyed to the preheating tank through the first inlet and heated to 65-85°C. It is then mixed with the mixed extractant to obtain the preheated material. The mixed extractant consists of a supplementary extractant conveyed through the second inlet of the preheating tank and a circulating extractant conveyed through the third inlet of the preheating tank. The mass ratio of the mixed extractant to the aged oil raw material is 1:2-1:

5.

2. The method according to claim 1, characterized in that, The flash-evaporated oil and gas pass through a heat exchanger and an oil-water separator to obtain circulating extractant, recovered extractant, wastewater, and non-condensable gas. The circulating extractant is then transported to a preheating tank, which includes: The flash oil vapor is transported to the heat exchanger through the first outlet of the flash tank. In the heat exchanger, it is cooled to 40-65°C by cooling circulating water to obtain cooled oil slurry. After cooling, the oil slurry is transported to the oil-water separator through the first inlet. A demulsifier is added through the second inlet of the oil-water separator to obtain circulating extractant, recovered extractant, wastewater and non-condensable gas. The circulating extractant is transported to the preheating tank through the third outlet of the oil-water separator.

3. The method according to claim 2, characterized in that, Non-condensable gas is transported to the exhaust gas purification system through the first outlet of the oil-water separator, and wastewater is transported to the wastewater treatment system through the second outlet of the oil-water separator; the recovered extractant is transported to the storage equipment through the third outlet of the oil-water separator.

4. The method according to claim 1, characterized in that, The remaining oil slurry from flash evaporation is transported to a three-phase centrifuge via the second outlet of the flash tank. In the three-phase centrifuge, the water phase, sludge, and oil phase are separated and then transported to the recycling system.

5. A hot water hydrolysis-extraction coupled system for treating aged oil, characterized in that, The system for the hot water hydrolysis-extraction coupled treatment of aged oil according to any one of claims 1-4 includes a pretreatment unit, a hydrothermal reaction unit, an extractant recovery unit, and a centrifugal separation unit; The pretreatment unit includes a preheating tank; the hydrothermal reaction unit includes a hydrothermal reactor; the extractant recovery unit includes a flash tank, a heat exchanger, and an oil-water separator connected in sequence; the centrifugal separation unit includes a three-phase centrifuge; wherein... The outlet of the pretreatment unit is connected to the inlet of the hydrothermal reaction unit, and the outlet of the hydrothermal reaction unit is connected to the inlet of the extractant recovery unit; One outlet of the extractant recovery unit is connected to the inlet of the pretreatment unit; the other outlet of the extractant recovery unit is connected to the inlet of the centrifugal separation unit. The preheating tank has three inlets and one outlet; among them... The first inlet of the preheating tank is used to transport aged oil raw material; the second inlet of the preheating tank is used to transport supplementary extractant; the third inlet of the preheating tank is used to transport recycled extractant after being recovered by the extractant recovery unit. The outlet of the preheating tank is used to transport preheated materials to the hydrothermal reactor.

6. The system according to claim 5, characterized in that, The flash tank has two outlets: the first outlet is connected to the heat exchanger inlet; the second outlet is connected to the three-phase centrifuge; and the flash tank inlet is connected to the outlet of the hydrothermal reactor.

7. The system according to claim 6, characterized in that, The three-phase centrifuge has three outlets, which are used to output the centrifugally separated oil phase, centrifugally separated water phase, and centrifugally separated sludge, respectively.

8. The system according to claim 6, characterized in that, The oil-water separator has two inlets and four outlets; among them... The first inlet of the oil-water separator is connected to the outlet of the heat exchanger; the second inlet of the oil-water separator is connected to an external pipeline used to transport the demulsifier. The first outlet of the oil-water separator is connected to the exhaust gas purification system to transport the non-condensable gas generated in the oil-water separator to the exhaust gas purification system; the second outlet of the oil-water separator is connected to the wastewater treatment system to transport the oil-water mixture generated in the oil-water separator to the wastewater treatment system; the third outlet of the oil-water separator is connected to the storage device to transport the upper layer recovered extractant generated in the oil-water separator to the storage device; and the fourth outlet of the oil-water separator is connected to the preheating tank to transport the circulating extractant to the preheating tank.

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