A continuous supercritical water oxidation system for treating oil-containing sludge

Abstract

The application provides a continuous supercritical water oxidation system for treating oily sludge, which comprises a sludge-water mixing feeding system, a supercritical oxidation system and an energy recovery system. When the whole system is initially started, the heat of an electric heating plug is used to ignite the fuel in a reaction inclined pipe, so that the rapid preheating and efficient degradation of the organic waste liquid are realized, and the investment and energy consumption of the equipment are reduced. By adjusting the opening and closing of the first electric ball valve and the second electric ball valve, the mixing of the oily sludge and clean water / organic waste water and the continuous feeding of the sludge and water are realized. The sludge and water and the unpreheated high-pressure oxidizing agent are reacted in the reaction inclined pipe, and by adjusting the opening and closing of the third electric ball valve and the fourth electric ball valve, the automatic salt discharge can be realized, so that the generation of the salt-containing sewage is avoided, the continuous operation and zero emission of the reactor are beneficial, and the industrial treatment demand is met.

Description

Technical Field

[0001] This invention relates to the field of supercritical water oxidation, and more particularly to a continuous supercritical water oxidation system for treating oily sludge. Background Technology

[0002] Oily sludge is mainly generated in oil fields and refineries. Taking the petroleum exploration and development industry as an example, its generation accounts for 0.5% to 1% of crude oil production. Based on current crude oil production estimates in my country, nearly one million tons of oily sludge and oil sands will be generated annually. If the "three sludges" (oil, oil, and sludge) generated by the petrochemical industry are included, the total amount will be much larger. Oily sludge entering surface soil and water bodies will cause serious pollution problems; therefore, effective treatment is necessary before discharge.

[0003] Currently, there are few reports in the literature on the treatment of oil sludge, and the main method still used is incineration. However, incineration requires the use of dust removal and gas recovery devices, otherwise it will cause serious air pollution. In addition, there are low-temperature pyrolysis, dissolution and washing, and microbial treatment methods. However, the first two methods are relatively complex and will cause secondary pollution to the environment. Microorganisms have a certain selectivity for oil products and their application conditions are relatively harsh, and they are not yet mature.

[0004] Supercritical water oxidation (SCWO) technology refers to an advanced oxidation technology that degrades organic matter into harmless small molecules such as CO2, N2, and H2O under conditions of 23-30 MPa and 400-600℃, using supercritical water as the reaction medium and air, O2, or H2O2 as the oxidant. Cl, P, and S are usually converted into corresponding acids or precipitated as inorganic salts. SCWO technology has been recognized by the United States as the most promising key technology for waste treatment in the energy and environment field. Although the application foundation has been established and there are already some SCWO industrial plants at home and abroad, reactor corrosion, salt deposition, and high operating costs have hindered the industrial promotion of this technology.

[0005] The supercritical water oxidation device, patent number CN104291546A, can be used for the treatment of municipal sludge. The main body consists of an inclined tube reactor and a vertically placed straight tube separator. Waste preheated to 200°C is mixed with an oxidant and supercritical water at 500-600°C before entering the inclined tube reactor. The inclined tube is lined with a porous inner tube, and the boundary fluid forms a protective film on the inner surface of the liner, preventing solid particles from depositing on the reactor wall, reducing corrosion and salt deposition of the reaction products, and lowering the (10⁻⁴) inner wall temperature of the inclined tube, ensuring safe operation and reducing material requirements. In the separator, the product undergoes solid-liquid separation through gravity settling, and cooling water neutralizes and cools it, while dissolving and discharging solid particles at the bottom of the separator. However, as the reaction proceeds, the device requires continuous supply of 500-600°C supercritical water, resulting in high operating costs. Furthermore, the dissolution and discharge of solid particles causes secondary pollution, making zero-emission impossible and hindering continuous operation.

[0006] To address the preheating issue of materials, patent CN102190363A describes a supercritical water oxidation reactor that utilizes auxiliary fuel for heat supply. This method employs auxiliary fuel to provide the necessary heat for the reaction, and jets in different directions efficiently mix the materials, fuel, and oxidant (air or oxygen) to improve oxidation efficiency. However, this device suffers from difficulties in fuel ignition and requires a preheater before entering the reactor along with the oxidant, resulting in high operating costs. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a continuous supercritical water oxidation system for treating oily sludge, which solves the problems of high operating costs during material preheating and secondary pollution during reactor salt discharge.

[0008] The technical solution of this invention:

[0009] A continuous supercritical water oxidation system for treating oily sludge includes a sludge-water mixing and feeding system, a supercritical oxidation system, and an energy recovery system.

[0010] The mud-water mixing and feeding system consists of a first booster pump (1), a first one-way valve (2), a jet mixer (3), an oil sludge tank (4), a first electric ball valve (5), a mixing pipe (6), a second electric ball valve (7), a mixing tank (8), and a second one-way valve (9). The oil sludge tank (4) consists of a tank body (4-1) and a sludge discharge port (4-2). The mixing tank (8) consists of a tank body (8-1), a water inlet (8-2), a water outlet (8-3), and a mud-water discharge port (8-4).

[0011] The inlet of the first booster pump (1) is a clean water or organic wastewater inlet. The outlet of the first booster pump (1) is connected to the inlet of the first check valve (2) via a pipeline. The outlet of the first check valve (2) is connected to the working fluid inlet at the left end of the pipeline jet mixer (3). The mixing fluid outlet at the right end of the jet mixer (3) is connected to the water inlet (8-2) of the mixing tank (8) via a pipeline. The sludge discharge port (4-2) of the sludge tank (4) is connected to the inlet of the first electric ball valve (5) via a flange. The outlet of the first electric ball valve (5) is connected to the inlet of the mixing pipe (6) via a flange. The outlet of the mixing pipe (6) is connected to the inlet of the second electric ball valve (7) via a flange. The outlet of the second electric ball valve (7) is connected to the drain port (8-3) of the mixing tank (8) via a flange. The mud and water discharge port (8-4) of the mixing tank (8) is connected to the inlet of the second check valve (9) via a pipeline.

[0012] The supercritical water oxidation system consists of three parts: an ignition zone, a reaction zone, and a separation zone. The core device of the supercritical water oxidation system is a supercritical water oxidation reactor (10). The supercritical water oxidation reactor (10) consists of an inclined tube end cap (10-1), a feed inlet (10-2), a first oxidant inlet (10-3), a reaction inclined tube (10-4), a T-shaped porous inner liner (10-5), an inclined tube boss (10-6), a second oxidant inlet (10-7), a separation straight tube (10-8), a straight tube end cap (10-9), an exhaust port (10-10), a third electric ball valve (10-11), a sludge discharge pipe (10-12), and a fourth electric ball valve (10-13).

[0013] The ignition zone is composed of a second booster pump (11), a first shut-off valve (12), a third check valve (13), an inclined tube end cap (10-1), a feed inlet (10-2), an oxidant booster device (14), a second shut-off valve (15), a first oxidant inlet (10-3), and a glow plug (16).

[0014] The inlet of the second booster pump (11) is the fuel inlet. The outlet of the second booster pump (11) is connected to the inlet of the first shut-off valve (12) via a pipe. The outlet of the first shut-off valve (12) is connected to the inlet of the third check valve (13) via a pipe. The upper end of the inclined tube end cap (10-1) is provided with a feed port (10-2) and a first oxidant inlet (10-3). The outlet of the third check valve (13) is connected to the feed port (10-2) via a pipe. The inlet of the oxidant booster device (14) is the oxidant inlet. The outlet of the oxidant booster device (14) is connected to the inlet of the second shut-off valve (15). The outlet of the second shut-off valve (15) is connected to the first oxidant inlet (10-3) via a pipe. The glow plug (16) is threadedly connected to the center of the inclined tube end cap (10-1).

[0015] The reaction zone consists of a second one-way valve (9), a third one-way valve (13), an inclined tube end cap (10-1), a feed inlet (10-2), an oxidant pressurization device (14), a second shut-off valve (15), a first oxidant inlet (10-3), a reaction inclined tube (10-4), a T-shaped porous inner liner (10-5), an inclined tube boss (10-6), a third shut-off valve (17), and a second oxidant inlet (10-7).

[0016] The outlet of the second one-way valve (9) is connected to the inlet (10-2) via a pipeline and then connected in parallel with the outlet of the third one-way valve (13). The inclined tube end cap (10-1) is located on the upper end of the reaction inclined tube (10-4). The reaction inclined tube (10-4) is equipped with a T-shaped porous inner liner (10-5). The upper end of the T-shaped porous inner liner (10-5) is a protruding end. The inner side of the reaction inclined tube (10-4) is equipped with an inclined tube boss (10-6) for fixing the T-shaped porous inner liner (10-5). The inlet of the third shut-off valve (17) is connected to the oxidant pressurization device (14) via a pipeline and then connected in parallel with the inlet of the second shut-off valve (15). The outlet of the third shut-off valve (17) is connected to the second oxidant inlet (10-7) via a pipeline.

[0017] The separation zone consists of a separation straight pipe (10-8), a straight pipe end cap (10-9), an exhaust port (10-10), a third electric ball valve (10-11), a sludge discharge pipe (10-12), a fourth electric ball valve (10-13), a back pressure valve (18), and a flash tank (19).

[0018] The upper end of the separation straight pipe (10-8) is provided with a straight pipe end cap (10-9), and the center of the straight pipe end cap (10-9) is provided with an exhaust port (10-10). The lower end of the separation straight pipe (10-8) is connected to the inlet of the third electric ball valve (10-11) via a flange. The outlet of the third electric ball valve (10-11) is connected to the inlet of the sludge discharge pipe (10-12) via a flange. The outlet of the sludge discharge pipe (10-12) is connected to the inlet of the fourth electric ball valve (10-13) via a flange. The outlet of the fourth electric ball valve (10-13) is connected to the inlet of the back pressure valve (18) via a pipe. The outlet of the back pressure valve (18) is connected to the inlet of the flash tank (19) via a pipe. The top of the flash tank (19) is a gas phase discharge port, and the bottom of the flash tank (19) is a solid phase discharge port.

[0019] The reaction inclined tube (10-4) and the separation straight tube (10-8) are welded at a certain angle. The separation straight tube (10-8) has an opening in the middle for inserting a T-shaped porous inner liner tube (10-5) to ensure that the product in the reaction inclined tube (10-4) flows into the separation straight tube (10-8).

[0020] The energy recovery system consists of a heat exchanger (20), a gas-liquid separator (21), a buffer tank (22), an expander (23), a generator (24), a fourth check valve (25), and a jet mixer (3). The tube-side inlet of the heat exchanger (20) is connected to the exhaust port (10-10) of the supercritical water oxidation system via a pipeline, and the tube-side outlet of the heat exchanger (20) is connected to the inlet of the gas-liquid separator (21) via a pipeline. The shell-side fluid of the heat exchanger (20) is cooling water, used to produce high-temperature steam. The gas phase outlet of the gas-liquid separator (21) is connected to the inlet of the buffer tank (22) via a pipeline. The outlet of the buffer tank (22) is connected to the inlet of the expander (23) via a pipeline. The expander (23) is connected to the generator (24) via a drive shaft. The outlet of the expander (23) is the exhaust steam outlet. The liquid phase outlet of the gas-liquid separator (21) is connected to the inlet of the fourth check valve (25) via a pipeline. The outlet of the fourth check valve (25) is connected to the ejector fluid inlet at the lower end of the jet mixer (3) via a pipeline.

[0021] The maximum operating pressure of each component in the ignition zone, reaction zone, and separation zone of the supercritical water oxidation system is 30 MPa.

[0022] The highest operating temperature of the T-shaped porous liner tube (10-5) in the reaction zone is 1200℃, and the highest operating temperature of the other components in the reaction and separation zones is 700℃.

[0023] The oxidant pressurization device (14) is a plunger pump or a compressor.

[0024] The T-shaped porous inner liner (10-5) is made of one of zirconium oxide, alumina, or silicon carbide.

[0025] The oxidant is selected from one of air, oxygen, hydrogen peroxide, KClO3 solution, and KMnO4 solution.

[0026] The fuel selected is one of gasoline, kerosene, methanol, or ethanol.

[0027] The advantages of this invention are:

[0028] 1. This invention utilizes the heat from the heating core of the glow plug to ignite the fuel in the inclined reaction tube, enabling the temperature in the reaction zone to quickly reach the required level, thus achieving rapid preheating of the mud and water and efficient degradation of organic matter in the mud and water.

[0029] 2. The fuel does not require high-temperature preheating during the entire heating process, reducing equipment investment and energy consumption;

[0030] 3. By adjusting the opening and closing of the first and second electric ball valves at the lower end of the sludge tank, continuous mixing of sludge with clean water / organic wastewater can be achieved, while reducing the material requirements of the sludge tank;

[0031] 4. By adjusting the opening and closing of the third and fourth electric ball valves at the lower end of the separation straight pipe, the reactor can achieve automatic sludge and water control, avoiding the generation of wastewater when using cooling water for cooling, achieving zero discharge, which is conducive to the continuous operation of the reactor and meets the needs of industrial treatment.

[0032] 5. Make full use of the energy of the reaction products. Use the heat energy of the reaction products to preheat the mud and water, and use the pressure energy to power the expander to generate electricity. The generated electricity can supply the operation of the first booster pump, the second booster pump, and the oxidant booster device, thereby reducing the system operating cost. Attached Figure Description

[0033] Figure 1 is a schematic diagram of the structure of the continuous supercritical water oxidation system for treating oily sludge.

[0034] Figure 2 is a schematic diagram of the slurry feeding process in the slurry mixing and feeding system.

[0035] Figure 3 is a schematic diagram of the mud-water deposition process in the mud-water mixing and feeding system.

[0036] Figure 4 is a schematic diagram of the mud-water deposition process in the reactor.

[0037] Figure 5 is a schematic diagram of the sludge discharge process in the reactor.

[0038] In the diagram: 1. First booster pump; 2. First check valve; 3. Jet mixer; 4. Sludge tank; 4-1. Sludge tank body; 4-2. Sludge discharge port; 5. First electric ball valve; 6. Mixing pipe; 7. Second electric ball valve; 8. Mixing tank; 8-1. Mixing tank body; 8-2. Water inlet; 8-3. Drain outlet; 8-4. Sludge discharge outlet; 9. Second check valve; 10. Supercritical water oxidation reactor; 10-1. Inclined tube end cap; 10-2. Feed inlet; 10-3. First oxidant inlet; 10-4. Inclined reaction tube; 10-5. T-shaped porous inner liner; 10-6. Inclined tube boss; 10-7. Second oxidant inlet; 10-8. Separation straight pipe; 10-9. Straight pipe end cap; 10-10 10-11. Exhaust port; 10-12. Third electric ball valve; 10-13. Sludge discharge pipe; 10-14. Fourth electric ball valve; 11. Second booster pump; 12. First shut-off valve; 13. Third check valve; 14. Oxidant booster device; 15. Second shut-off valve; 16. Electric

[0039] 17. Hot plug; 18. Third shut-off valve; 19. Back pressure valve; 20. Flash tank; 21. Heat exchanger; 22. Gas-liquid separator; 23. Buffer tank; 24. Expander; 25. Generator; 26. Fourth check valve. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0041] As shown in Figure 1, the present invention provides a continuous supercritical water oxidation system for treating oily sludge, comprising: a sludge-water mixing and feeding system, a supercritical water oxidation system, and an energy utilization system.

[0042] Example 1:

[0043] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0044] In this embodiment, the mud-water is a mixture of oily sludge and organic wastewater, with an organic content of 4%.

[0045] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0046] The specific process of this embodiment is as follows:

[0047] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0048] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 23MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second electric ball valve (7) is opened. The high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water. The sludge-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200℃.

[0049] 3. SCWO Reaction Process: When the temperature inside the inclined reaction tube (10-4) rises to 600℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. Preheated mud-water at 200℃ and a pressure of 23MPa, and unpreheated air at a pressure of 30MPa, enter the inclined reaction tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic content in the mud-water reaches more than 2%, the required reaction temperature can be maintained by the heat released from oxidation during the reaction. Simultaneously, unpreheated air at a pressure of 23MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous inner liner tube (10-5), minimizing corrosion and salt deposition caused by the reaction, and also acting as the oxidant for SCWO.

[0050] After the material enters the inclined reaction tube (10-4), it flows downward along the T-shaped porous inner liner tube (10-5), and the SCWO reaction occurs along the way.

[0051] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the exhaust port (10-10) at the top of the separation straight pipe (10-8), while the mud and water flow into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settle at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the mud and water in the mud discharge pipe (10-12) rises continuously. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens. The mud and water is discharged from the outlet of the fourth electric ball valve (10-13) and then reduced to 0 by the back pressure valve (18). At 1 MPa, supercritical water in the muddy water evaporates, and the separation of mud and water is achieved in the flash tank (19). The supercritical water is depressurized into high-temperature steam and discharged from the gas phase outlet at the top of the flash tank (19), while the mud and sand are discharged from the solid outlet at the bottom of the flash tank (19).

[0052] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0053] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0054] Example 2:

[0055] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0056] In this embodiment, the mud-water is a mixture of oily sludge and organic wastewater, with an organic content of 4%.

[0057] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0058] The specific process of this embodiment is as follows:

[0059] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0060] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6), and the organic wastewater is pressurized to 30MPa in the first booster pump (1) and then...

[0061] The first one-way valve (2) enters the mixing tank (8) through the inlet (8-2). Then, the first electric ball valve (5) closes and the second electric ball valve (7) opens, allowing high-pressure wastewater to flow into the mixing pipe (6) and mix with the oil sludge to form mud-water. The mud-water is then mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200°C.

[0062] 3. SCWO Reaction Process: When the temperature inside the inclined reaction tube (10-4) rises to 600℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. Preheated mud-water at 200℃ and a pressure of 30MPa, and unpreheated air at a pressure of 30MPa, enter the inclined reaction tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic content in the mud-water reaches more than 2%, the temperature required for the reaction can be maintained by the heat released from oxidation during the reaction process. Simultaneously, unpreheated air at a pressure of 30MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous inner liner tube (10-5), minimizing corrosion and salt deposition caused by the reaction, and also acting as the oxidant for SCWO. After the material enters the inclined reaction tube (10-4), it flows downward along the T-shaped porous inner liner tube (10-5), and the SCWO reaction occurs along the way.

[0063] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid outlet at the bottom of the flash tank (19).

[0064] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0065] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0066] Example 3:

[0067] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0068] In this embodiment, the mud-water is a mixture of oily sludge and organic wastewater, with an organic content of 4%.

[0069] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0070] The specific process of this embodiment is as follows:

[0071] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0072] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 23MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second electric ball valve (7) is opened. The high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water. The sludge-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200℃.

[0073] 3. SCWO Reaction Process: When the temperature inside the inclined reaction tube (10-4) rises to 550℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. Preheated mud-water at 200℃ and a pressure of 23MPa, and unpreheated air at a pressure of 30MPa, enter the inclined reaction tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic content in the mud-water reaches more than 2%, the temperature required for the reaction can be maintained by the heat released from oxidation during the reaction process. Simultaneously, unpreheated air at a pressure of 23MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous inner liner tube (10-5), minimizing corrosion and salt deposition caused by the reaction, and also acting as the oxidant for SCWO. After the material enters the inclined reaction tube (10-4), it flows downward along the T-shaped porous inner liner tube (10-5), and the SCWO reaction occurs along the way.

[0074] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the exhaust port (10-10) at the top of the separation straight pipe (10-8), while the mud and water flow into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settle at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the mud and water in the mud discharge pipe (10-12) rises continuously. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens. The mud and water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). The supercritical water in the mud and water evaporates, and the separation of mud and water is achieved in the flash tank (19). The high-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and the mud and sand are discharged from the solid phase outlet at the bottom of the flash tank (19).

[0075] Discharged through the outlet.

[0076] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0077] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0078] Example 4

[0079] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0080] In this embodiment, the mud-water is a mixture of oily sludge and organic wastewater, with an organic content of 4%.

[0081] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0082] The specific process of this embodiment is as follows:

[0083] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0084] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 30MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second electric ball valve (7) is opened. The high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water. The sludge-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200℃.

[0085] 3. SCWO Reaction Process: When the temperature inside the inclined reaction tube (10-4) rises to 550℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. Preheated mud-water at 200℃ and a pressure of 30MPa, and unpreheated air at a pressure of 30MPa, enter the inclined reaction tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic content in the mud-water reaches more than 2%, the temperature required for the reaction can be maintained by the heat released from oxidation during the reaction process. Simultaneously, unpreheated air at a pressure of 30MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous inner liner tube (10-5), minimizing corrosion and salt deposition caused by the reaction, and also acting as the oxidant for SCWO. After the material enters the inclined reaction tube (10-4), it flows downward along the T-shaped porous inner liner tube (10-5), and the SCWO reaction occurs along the way.

[0086] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid outlet at the bottom of the flash tank (19).

[0087] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0088] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0089] Example 5:

[0090] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0091] In this embodiment, the mud-water is a mixture of oily sludge and clean water, with an organic matter content of 1%.

[0092] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0093] The specific process of this embodiment is as follows:

[0094] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0095] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 23MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second...

[0096] The electric ball valve (7) is opened, and the high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the oil sludge to form mud-water. The mud-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200°C.

[0097] 3. SCWO reaction process: When the temperature inside the reaction inclined tube (10-4) rises to 600℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. The mud water preheated to 200℃ and pressure of 23MPa and the air not preheated and pressure of 23MPa enter the reaction inclined tube (10-4) through the feed port (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic matter content is below 2%, the temperature required for the reaction cannot be maintained by the heat released by the oxidation during the reaction process alone. Therefore, the organic wastewater needs to be mixed with a certain amount of fuel before entering the reaction inclined tube (10-4). Meanwhile, unheated air at a pressure of 23 MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous liner (10-5), minimizing corrosion and salt deposition caused by the reaction, and also serving as the oxidant for SCWO. After entering the inclined reaction tube (10-4), the material flows downward along the T-shaped porous liner (10-5), and the SCWO reaction occurs along the way.

[0098] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid phase outlet at the bottom of the flash tank (19).

[0099] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0100] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0101] Example 6:

[0102] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0103] In this embodiment, the mud-water is a mixture of oily sludge and clean water, with an organic matter content of 1%.

[0104] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0105] The specific process of this embodiment is as follows:

[0106] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0107] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 30MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second electric ball valve (7) is opened. The high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water. The sludge-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200℃.

[0108] 3. SCWO reaction process: When the temperature inside the reaction inclined tube (10-4) rises to 600℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. The mud water preheated to 200℃ and pressure of 30MPa and the air not preheated and pressure of 30MPa enter the reaction inclined tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic matter content is below 2%, the temperature required for the reaction cannot be maintained by the heat released by the oxidation during the reaction process alone. Therefore, the organic wastewater needs to be mixed with a certain amount of fuel before entering the reaction inclined tube (10-4). Meanwhile, unheated air at a pressure of 30 MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous liner (10-5), minimizing corrosion and salt deposition caused by the reaction, and also serving as the oxidant for SCWO. After entering the inclined reaction tube (10-4), the material flows downward along the T-shaped porous liner (10-5), and the SCWO reaction occurs along the way.

[0109] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid phase outlet at the bottom of the flash tank (19).

[0110] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0111] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0112] Example 7:

[0113] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0114] In this embodiment, the mud-water is a mixture of oily sludge and clean water, with an organic matter content of 1%.

[0115] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0116] The specific process of this embodiment is as follows:

[0117] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0118] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) is opened and the second electric ball valve (7) is closed. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 23MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) is closed and the second electric ball valve (7) is opened. The high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water. The sludge-water is mixed with the high-temperature water separated by the gas-liquid separator (21) and preheated to 200℃.

[0119] 3. SCWO reaction process: When the temperature inside the reaction inclined tube (10-4) rises to 550℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. The mud water preheated to 200℃ and pressure of 23MPa and the air not preheated and pressure of 23MPa enter the reaction inclined tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic matter content is below 2%, the temperature required for the reaction cannot be maintained by the heat released by the oxidation during the reaction process alone. Therefore, the organic wastewater needs to be mixed with a certain amount of fuel before entering the reaction inclined tube (10-4). Meanwhile, unheated air at a pressure of 23 MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous liner (10-5), minimizing corrosion and salt deposition caused by the reaction, and also serving as the oxidant for SCWO. After entering the inclined reaction tube (10-4), the material flows downward along the T-shaped porous liner (10-5), and the SCWO reaction occurs along the way.

[0120] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid phase outlet at the bottom of the flash tank (19).

[0121] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0122] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

[0123] Example 8:

[0124] In this embodiment, air is used as the oxidant, gasoline is used as the fuel, and the T-shaped porous inner liner (10-5) is made of zirconium oxide. In this embodiment, the pressure in the sludge tank (4) is the local atmospheric pressure.

[0125] In this embodiment, the mud-water is a mixture of oily sludge and clean water, with an organic matter content of 1%.

[0126] In this embodiment, the amount of oxidant used is twice the theoretical oxygen requirement for the complete oxidation of organic matter in the wastewater.

[0127] The specific process of this embodiment is as follows:

[0128] 1. Ignition and heating process: When ignition begins, the first shut-off valve (12), the second shut-off valve (15), and the third shut-off valve (17) are opened. The gasoline is pressurized to 1MPa in the second booster pump (11) and then enters the reaction inclined tube (10-4) through the feed port (10-2) via the third one-way valve (13). At the same time, the air is pressurized to 1MPa in the compressor (14) and then split into two paths. One path enters the reaction inclined tube (10-4) through the first oxidant inlet (10-3) and burns after contacting the gasoline at the heating core of the glow plug (16). The temperature inside the reaction inclined tube (10-4) rises rapidly. The other path enters the reaction inclined tube (10-4) through the second oxidant inlet (10-7) to prevent the inner wall of the inclined tube from overheating.

[0129] 2. Sludge-water mixing and feeding process: At the start of mixing, the first electric ball valve (5) opens and the second electric ball valve (7) closes. The sludge in the sludge tank (4) enters the mixing pipe (6). The organic wastewater is pressurized to 30MPa in the first booster pump (1) and enters the mixing tank (8) through the inlet (8-2) via the first check valve (2). Then, the first electric ball valve (5) closes and the second electric ball valve (7) opens, and the high-pressure wastewater is flushed into the mixing pipe (6) and mixed with the sludge to form sludge-water mixture. Sludge-water and gas-liquid separator

[0130] (21) Mix the separated high-temperature water and preheat to 200°C.

[0131] 3. SCWO reaction process: When the temperature inside the reaction inclined tube (10-4) rises to 550℃, the glow plug (16) disconnects the power supply, the first shut-off valve (12) closes, and the second one-way valve (9) opens. The mud water preheated to 200℃ and pressure of 30MPa and the air not preheated and pressure of 30MPa enter the reaction inclined tube (10-4) through the feed inlet (10-2) and the first oxidant inlet (10-3) respectively to carry out the SCWO reaction. Since the organic matter content is below 2%, the temperature required for the reaction cannot be maintained by the heat released by the self-oxidation during the reaction process. Therefore, the organic wastewater needs to be mixed with a certain amount of fuel before entering the reaction inclined tube (10-4). Meanwhile, unheated air at a pressure of 30 MPa enters the inclined reaction tube (10-4) through the second oxidant inlet (10-7), acting as a permeating fluid. This forms a protective gas film on the inner surface of the T-shaped porous liner (10-5), minimizing corrosion and salt deposition caused by the reaction, and also serving as the oxidant for SCWO. After entering the inclined reaction tube (10-4), the material flows downward along the T-shaped porous liner (10-5), and the SCWO reaction occurs along the way.

[0132] 4. Separation process: When the reaction products reach the end of the T-shaped porous inner liner (10⁻⁵), they flow into the separation straight pipe (10⁻⁸). Under the action of gravity, the reaction products are separated into clean, upward-flowing supercritical fluid (water and gas without solid particles) and downward-flowing muddy water (mud, sand, inorganic salts, and water). During the separation process, the third electric ball valve (10-11) opens and the fourth electric ball valve (10-13) closes. The supercritical fluid is discharged from the vent (10-10) at the top of the separation straight pipe (10-8), while the muddy water flows into the mud discharge pipe (10-12) after passing through the third electric ball valve (10-11) and settles at the inlet of the fourth electric ball valve (10-13). As the reaction proceeds, the liquid level of the muddy water in the mud discharge pipe (10-12) continuously rises. When the liquid level reaches a certain height, the third electric ball valve (10-11) closes and the fourth electric ball valve (10-13) opens, and the muddy water is discharged from the outlet of the fourth electric ball valve (10-13) and reduced to 0.1 MPa by the back pressure valve (18). Supercritical water in the muddy water evaporates, and the mud and water are separated in the flash tank (19). High-temperature steam is discharged from the gas phase outlet at the top of the flash tank (19), and mud and sand are discharged from the solid phase outlet at the bottom of the flash tank (19).

[0133] 5. Energy utilization process: The supercritical fluid enters the heat exchanger (20) and heats the cooling water in it into high-temperature steam. At this time, the fluid temperature drops to 300℃. Then, it is separated in the gas-liquid separator (21). The high-temperature gas is dried in the buffer tank and enters the expander (22) to generate electricity. The exhaust steam is directly discharged into the air. The high-temperature water flows into the mixing tank (8) through the ejector fluid inlet at the lower end of the jet mixer (3) via the third one-way valve (25) to preheat the mud and water in the tank to 200℃.

[0134] In this embodiment, the oil content of the mud and sand discharged from the bottom of the flash tank (19) is less than 2wt‰.

Claims

1. A continuous supercritical water oxidation system for treating oily sludge, characterized in that, include: Slurry mixing and feeding system, supercritical oxidation system, energy recovery system, The mud-water mixing and feeding system consists of a first booster pump (1), a first one-way valve (2), a jet mixer (3), an oil sludge tank (4), a first electric ball valve (5), a mixing pipe (6), a second electric ball valve (7), a mixing tank (8), and a second one-way valve (9). The oil sludge tank (4) consists of a tank body (4-1) and a sludge discharge port (4-2). The mixing tank (8) consists of a tank body (8-1), a water inlet (8-2), a water outlet (8-3), and a mud-water discharge port (8-4). The inlet of the first booster pump (1) is a clean water or organic wastewater inlet. The outlet of the first booster pump (1) is connected to the inlet of the first check valve (2) via a pipeline. The outlet of the first check valve (2) is connected to the working fluid inlet at the left end of the pipeline jet mixer (3). The mixing fluid outlet at the right end of the jet mixer (3) is connected to the water inlet (8-2) of the mixing tank (8) via a pipeline. The sludge discharge port (4-2) of the sludge tank (4) is connected to the inlet of the first electric ball valve (5) via a flange. The outlet of the first electric ball valve (5) is connected to the inlet of the mixing pipe (6) via a flange. The outlet of the mixing pipe (6) is connected to the inlet of the second electric ball valve (7) via a flange. The outlet of the second electric ball valve (7) is connected to the drain port (8-3) of the mixing tank (8) via a flange. The mud and water discharge port (8-4) of the mixing tank (8) is connected to the inlet of the second check valve (9) via a pipeline. The supercritical water oxidation system consists of three parts: an ignition zone, a reaction zone, and a separation zone. The core device of the supercritical water oxidation system is a supercritical water oxidation reactor (10). The supercritical water oxidation reactor (10) consists of an inclined tube end cap (10-1), a feed inlet (10-2), a first oxidant inlet (10-3), a reaction inclined tube (10-4), a T-shaped porous inner liner (10-5), an inclined tube boss (10-6), a second oxidant inlet (10-7), a separation straight tube (10-8), a straight tube end cap (10-9), an exhaust port (10-10), a third electric ball valve (10-11), a sludge discharge pipe (10-12), and a fourth electric ball valve (10-13). The ignition zone consists of a second booster pump (11), a first shut-off valve (12), a third check valve (13), an inclined tube end cap (10-1), a feed inlet (10-2), an oxidant booster device (14), a second shut-off valve (15), a first oxidant inlet (10-3), and a glow plug (16). The inlet of the second booster pump (11) is the fuel inlet. The outlet of the second booster pump (11) is connected to the inlet of the first shut-off valve (12) via a pipe. The outlet of the first shut-off valve (12) is connected to the inlet of the third check valve (13) via a pipe. The upper end of the inclined tube end cap (10-1) is provided with a feed port (10-2) and a first oxidant inlet (10-3). The outlet of the third check valve (13) is connected to the feed port (10-2) via a pipe. The inlet of the oxidant booster device (14) is the oxidant inlet. The outlet of the oxidant booster device (14) is connected to the inlet of the second shut-off valve (15). The outlet of the second shut-off valve (15) is connected to the first oxidant inlet (10-3) via a pipe. The glow plug (16) is threadedly connected to the center of the inclined tube end cap (10-1). The reaction zone consists of a second one-way valve (9), a third one-way valve (13), an inclined tube end cap (10-1), a feed inlet (10-2), an oxidant pressurization device (14), a second shut-off valve (15), a first oxidant inlet (10-3), a reaction inclined tube (10-4), a T-shaped porous inner liner (10-5), an inclined tube boss (10-6), a third shut-off valve (17), and a second oxidant inlet (10-7). composition, The outlet of the second one-way valve (9) is connected to the inlet (10-2) via a pipeline and then connected in parallel with the outlet of the third one-way valve (13). The inclined tube end cap (10-1) is located on the upper end of the reaction inclined tube (10-4). The reaction inclined tube (10-4) is equipped with a T-shaped porous inner liner (10-5). The upper end of the T-shaped porous inner liner (10-5) is a protruding end. The inner side of the reaction inclined tube (10-4) is equipped with an inclined tube boss (10-6) for fixing the T-shaped porous inner liner (10-5). The inlet of the third shut-off valve (17) is connected to the oxidant pressurization device (14) via a pipeline and then connected in parallel with the inlet of the second shut-off valve (15). The outlet of the third shut-off valve (17) is connected to the second oxidant inlet (10-7) via a pipeline. The separation zone consists of a separation straight pipe (10-8), a straight pipe end cap (10-9), an exhaust port (10-10), a third electric ball valve (10-11), a sludge discharge pipe (10-12), a fourth electric ball valve (10-13), a back pressure valve (18), and a flash tank (19). The upper end of the separation straight pipe (10-8) is provided with a straight pipe end cap (10-9), and the center of the straight pipe end cap (10-9) is provided with an exhaust port (10-10). The lower end of the separation straight pipe (10-8) is connected to the inlet of the third electric ball valve (10-11) via a flange. The outlet of the third electric ball valve (10-11) is connected to the inlet of the sludge discharge pipe (10-12) via a flange. The outlet of the sludge discharge pipe (10-12) is connected to the inlet of the fourth electric ball valve (10-13) via a flange. The outlet of the fourth electric ball valve (10-13) is connected to the inlet of the back pressure valve (18) via a pipe. The outlet of the back pressure valve (18) is connected to the inlet of the flash tank (19) via a pipe. The top of the flash tank (19) is a gas phase discharge port, and the bottom of the flash tank (19) is a solid phase discharge port. The reaction inclined tube (10-4) and the separation straight tube (10-8) are welded at a certain angle. The separation straight tube (10-8) has an opening in the middle for inserting a T-shaped porous inner liner tube (10-5) to ensure that the product in the reaction inclined tube (10-4) flows into the separation straight tube (10-8). The energy recovery system consists of a heat exchanger (20), a gas-liquid separator (21), a buffer tank (22), an expander (23), a generator (24), a fourth check valve (25), and a jet mixer (3). The tube-side inlet of the heat exchanger (20) is connected to the exhaust port (10-10) of the supercritical water oxidation system via a pipeline, and the tube-side outlet of the heat exchanger (20) is connected to the inlet of the gas-liquid separator (21) via a pipeline. The shell-side fluid of the heat exchanger (20) is cooling water, used to produce high-temperature steam. The gas phase outlet of the gas-liquid separator (21) is connected to the inlet of the buffer tank (22) via a pipeline. The outlet of the buffer tank (22) is connected to the inlet of the expander (23) via a pipeline. The expander (23) is connected to the generator (24) via a drive shaft. The outlet of the expander (23) is the exhaust steam outlet. The liquid phase outlet of the gas-liquid separator (21) is connected to the inlet of the fourth check valve (25) via a pipeline. The outlet of the fourth check valve (25) is connected to the ejector fluid inlet at the lower end of the jet mixer (3) via a pipeline.

2. The continuous supercritical water oxidation system for treating oily sludge according to claim 1, characterized in that: The maximum operating pressure of each component in the ignition zone, reaction zone, and separation zone of the supercritical water oxidation system is 30 MPa. The maximum operating temperature of the T-shaped porous inner liner (10-5) in the reaction zone is 1200℃, and the maximum operating temperature of the other components in the reaction zone and separation zone is 700℃.

3. The continuous supercritical water oxidation system for treating oily sludge according to claim 1, characterized in that: The oxidant pressurization device (14) is a plunger pump or a compressor.

4. A continuous supercritical water oxidation system for treating oily sludge according to claim 1, characterized in that: The T-shaped porous inner liner (10-5) is made of one of zirconium oxide, alumina, or silicon carbide.

5. A continuous supercritical water oxidation system for treating oily sludge according to claim 1, characterized in that: The oxidant is selected from one of air, oxygen, hydrogen peroxide, KClO3 solution, and KMnO4 solution.

6. A continuous supercritical water oxidation system for treating oily sludge according to claim 1, characterized in that: The fuel selected is one of gasoline, kerosene, methanol, or ethanol.

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