Supercritical water oxidation reactor and method for treating organic waste streams

Abstract

The application discloses a supercritical water oxidation reaction device and method for treating organic waste liquid, which comprises a shell and a cavity formed by surrounding the shell, and the shell is provided with a feeding port, a gas phase product outlet and a solid-liquid product outlet which are communicated with the cavity; the cavity is used for making the organic waste liquid to have a supercritical water oxidation reaction to obtain a gas phase product and a solid phase product, and the solid phase product comprises deposited salt adhered to the cavity wall surface; the cavity is provided with a flushing assembly, the flushing assembly comprises a hollow rotating shaft which is rotationally connected with the shell and a plurality of branch pipes which are communicated with the side surface of the hollow rotating shaft, each branch pipe is provided with a plurality of inclined liquid outlets which are opposite to the cavity wall surface in the height direction, and the hollow rotating shaft is provided with a flushing liquid inlet; wherein the flushing liquid enters the hollow rotating shaft from the flushing liquid inlet and is sprayed to the cavity wall surface in an inclined manner through the plurality of inclined liquid outlets to remove the deposited salt adhered to the cavity wall surface, and the flushing assembly is driven to be in a rotating state through reaction force.

Description

Technical Field

[0001] This invention relates to the field of high-efficiency degradation treatment technology for organic waste liquid, and specifically to a supercritical water oxidation reactor and method for treating organic waste liquid. Background Technology

[0002] In recent years, my country's pharmaceutical, medical, and chemical (coal chemical, petrochemical) industries have generated massive amounts of wastewater and sludge, further leading to 80 million tons of hazardous waste annually, and 60 million tons of domestic sewage sludge produced annually. The large quantities of wastewater generated by these industries primarily contain toxic and harmful substances such as phenols, ammonia, olefins, aromatics, and tar, making it a highly concentrated and difficult-to-biodegrade industrial wastewater with poor biodegradability and extreme treatment challenges. Currently, domestic and international treatment methods mainly involve evaporation crystallization, incineration, ash flushing, natural evaporation ponds, and deep well injection, which are insufficient to truly achieve zero discharge of high-concentration organic wastewater at the terminal. The safe and efficient treatment and disposal of high-concentration, difficult-to-degrade organic wastewater, sludge, and hazardous organic waste discharged from industries such as petrochemicals, coal chemicals, pesticides, pharmaceuticals, and printing and dyeing are currently key, difficult, and critical issues in the environmental field, representing a significant demand for environmental pollution control and an urgent necessity for the survival and development of industries such as chemicals, pharmaceuticals, and pesticides. Statistics show that in recent years, environmental protection investment has increased year by year, mainly for treating high-salinity wastewater, sludge, and hazardous waste generated by various chemical enterprises.

[0003] Supercritical water oxidation technology is a novel method for water pollution control, characterized by its environmental friendliness, energy efficiency, and high efficiency, and has attracted widespread attention. However, when treating organic waste liquid with supercritical water oxidation, deposits form on the reactor walls, which hinders the reactor's operating efficiency and causes severe corrosion to the reactor's inner walls. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of salt deposition on the walls and low treatment efficiency in the supercritical water oxidation process for treating high-salt organic wastewater. It provides a supercritical water oxidation reaction device and method for treating organic wastewater, which can achieve efficient removal of organic matter from high-concentration, recalcitrant organic wastewater and simultaneous desalination and reconcentration, while reducing salt deposition on the reaction chamber walls.

[0005] To achieve the above objectives, the present invention provides a supercritical water oxidation reactor for treating organic waste liquid, comprising a shell and a cavity formed by the shell, wherein the shell is provided with a feed inlet communicating with the cavity, a gas phase product outlet and a solid-liquid product outlet;

[0006] The cavity is used to induce supercritical water oxidation of organic waste liquid to obtain gaseous products and solid products including deposited salts adhering to the cavity wall.

[0007] The cavity is equipped with a flushing assembly, which includes a hollow rotating shaft rotatably connected to the housing and multiple branch pipes communicating with the side of the hollow rotating shaft. Each branch pipe has multiple oblique liquid outlets along the height direction that are opposite to the wall of the cavity. The hollow rotating shaft is provided with a flushing liquid inlet.

[0008] The flushing fluid enters the hollow rotating shaft from the flushing fluid inlet and is sprayed obliquely onto the cavity wall through multiple oblique outlets set on the branch pipe to form a water film to remove the deposited salt adhering to the cavity wall. At the same time, the reaction force of flushing the wall drives the flushing assembly to rotate.

[0009] Preferably, a material dispersion component connected to the feed inlet is provided in the cavity around the hollow rotating shaft, which is used to distribute the reactants in the inner area formed by the multiple branch pipes.

[0010] Preferably, the inclined liquid outlet is inclined downward at 15° to 45° to the cavity wall.

[0011] Preferably, the plurality of the oblique liquid outlets are distributed in a sparse upper and dense lower pattern on the branch pipe.

[0012] Preferably, from top to bottom, the cross-sectional area of ​​the oblique liquid outlet on each of the branch pipes gradually increases.

[0013] Preferably, the feed inlet extends into the cavity to form a feed pipe, the hollow rotating shaft is sleeved in the feed pipe, and the annular gap formed between the bottom end of the feed pipe and the hollow rotating shaft is configured as a nozzle structure, which is formed as the material dispersing component.

[0014] Preferably, the rinsing assembly is configured as a stirring paddle structure, the stirring shaft of the stirring paddle structure is formed as the hollow rotating shaft, and the paddle blades of the stirring paddle structure are formed as the branch pipe.

[0015] Another aspect of the present invention provides a supercritical water oxidation reaction method for treating organic waste liquid, the method being carried out in the supercritical water oxidation reaction apparatus described in the present invention, and comprising the following:

[0016] A mixture containing organic waste liquid and oxidant is introduced into the feed inlet, and the mixture reacts under supercritical water oxidation conditions to obtain gaseous products and solid products containing deposited salts adhering to the cavity wall.

[0017] Simultaneously, flushing fluid is fed into the flushing fluid inlet. The flushing fluid enters the hollow rotating shaft and is sprayed obliquely onto the cavity wall through multiple oblique outlets set on the branch pipe, causing the flushing assembly to rotate and remove the deposited salt adhering to the cavity wall.

[0018] The solid product containing inorganic salts is redissolved in the subcritical region to form a solid-liquid product, which is discharged from the solid-liquid product outlet, and the gaseous product is discharged from the gaseous product outlet.

[0019] Preferably, the material introduced into the feed inlet is dispersed into the reaction chamber through the material dispersion component.

[0020] Preferably, the reaction conditions for the supercritical water oxidation reaction include: a temperature of 375–620°C, more preferably 395–560°C; and a pressure of 22–31 MPa, more preferably 22–28 MPa.

[0021] Preferably, the method includes:

[0022] 1) Provide supercritical water oxidation reaction conditions through fuel combustion: preheated fuel is introduced into the feed inlet, and the fuel comes into contact with oxygen in the cavity, and combustion releases heat to form a supercritical reaction zone that can provide supercritical water oxidation reaction conditions for step 2).

[0023] The supercritical reaction zone is surrounded by a subcritical zone with a lower temperature, which is used to dissolve the inorganic salts produced by the supercritical oxidation reaction.

[0024] 2) Supercritical water oxidation reaction: The fuel introduced into the feed port is switched to a mixture containing organic waste liquid and oxidant. The mixture undergoes a supercritical water oxidation reaction in the supercritical reaction zone to obtain gaseous products and solid products containing deposited salts adhering to the cavity wall.

[0025] Preferably, the rinsing solution is selected from water or an aqueous solution of sodium bicarbonate.

[0026] Preferably, the fuel is selected from at least one of methanol aqueous solution, ethanol aqueous solution or isopropanol aqueous solution.

[0027] Preferably, the preheating temperature of the fuel is 350–373°C;

[0028] Preferably, the organic waste liquid comes from coal chemical or petrochemical sources.

[0029] Preferably, the organic waste liquid is selected from one or more mixtures of high-concentration organic wastewater, high-salt organic wastewater, and mixed-salt organic mother liquor.

[0030] Preferably, the oxidant is selected from oxygen-containing gases and / or hydrogen peroxide.

[0031] Preferably, the mixture further includes a combustion improver and a modifier.

[0032] More preferably, the combustion-supporting agent includes a combustion-supporting organic solvent; more preferably, the combustion-supporting organic solvent is selected from at least one of ethanol, isopropanol, and methanol;

[0033] More preferably, the regulator is selected from water, alkaline solution and acidic solution.

[0034] Preferably, the supercritical water oxidation reaction is carried out in the presence of a catalyst, which is selected from homogeneous catalysts and / or heterogeneous catalysts;

[0035] More preferably, the homogeneous catalyst is selected from one or more of sodium hydroxide, soluble transition metal salts, basic salts, and heteropolyacids;

[0036] More preferably, the soluble transition metal salt includes nitrates and / or sulfates, and the soluble transition metal includes at least one of Cu, Fe, Mn, Ni and Co;

[0037] More preferably, the alkaline salt includes sodium carbonate and / or sodium bicarbonate;

[0038] More preferably, the heteropolyacid includes at least one of phosphotungstic acid, silicotungstic acid, and phosphomolybdic acid.

[0039] Preferably, the heterogeneous catalyst is selected from one or more of noble metal elements, activated carbon, metal oxides, and supported catalysts;

[0040] More preferably, the noble metal element includes at least one of Pt, Pd, Rh, Ru, and Ag;

[0041] More preferably, the metal oxide includes one or more of MgO, NiO, MnO2, and Cr2O3;

[0042] More preferably, the supported catalyst includes CeO2 or MnO2-ZrO2.

[0043] The advantages of this invention compared to the prior art are as follows:

[0044] (1) This novel supercritical water treatment device has a scientific and reasonable overall design, simple structure, and convenient operation. By setting up a flushing component in the reactor, on the one hand, the water mist sprayed from multiple inclined outlets can remove the deposited salt on the cavity wall, and on the other hand, it can exchange heat with the cavity wall, so that the temperature of the inner wall of the reactor is lower than the temperature of the supercritical reaction zone. This allows the salt generated by the reaction and the deposited salt adsorbed on the cavity wall to dissolve again into a liquid phase and fall to the bottom of the reactor for discharge.

[0045] (2) In view of the problem of uneven premixing of reactants in traditional reactors, or the problem of needing to add an extra mixer to increase design difficulty and construction cost, the material dispersion component of the present invention can realize further atomization and full mixing of reactants, improve the treatment effect, and at the same time control the area of ​​material spraying to the inside of the hydrocyclone stirring paddle, which can avoid salt deposition on the inner wall surface of the reactor to a certain extent.

[0046] (3) The present invention can stabilize the temperature and pressure during the reaction process and reduce the operational risk by controlling the feed rate and spray intensity of the reactants and coordinating the spray intensity and rotation speed of the stirring paddle structure.

[0047] Other advantages of the present invention will be described in detail in the specific embodiments, and will not be elaborated here. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the supercritical water oxidation reactor for treating organic waste liquid according to a specific implementation method.

[0049] Explanation of reference numerals in the attached figures

[0050] 1. Feed inlet; 2. Rinsing fluid inlet; 3. Gas phase product outlet; 4. Solid-liquid product outlet; 5. Shell; 6. Cavity wall; 7. Feed pipe; 8. Nozzle structure; 9. Stirring shaft; 10. Stirring paddle structure; 11. Paddle blade; 12. Angled liquid outlet; 13. Supercritical reaction zone. Detailed Implementation

[0051] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0052] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0053] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right positions shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer positions relative to the outline of each component itself. In this invention, unless otherwise stated, the "upper part" of the container refers to the position of 0-30% of the container from top to bottom; the "middle part" of the container refers to the position of 30-70% of the container from top to bottom.

[0054] like Figure 1As shown, the present invention provides a supercritical water oxidation reactor for treating organic waste liquid, including a shell 5 made of heat-resistant and high-pressure resistant material and a cavity formed around the shell 5. The shell 5 is provided with a feed inlet 1, a gas phase product outlet 3 and a solid-liquid product outlet 4 communicating with the cavity. The gas phase feed inlet is located at the top of the shell and the solid-liquid product outlet is located at the bottom of the shell.

[0055] The chamber is used to induce supercritical water oxidation of organic waste liquid to obtain gaseous products and solid products including deposited salts adhering to the chamber wall 6.

[0056] A flushing assembly is installed in the cavity. The flushing assembly includes a hollow rotating shaft rotatably connected to the housing 5 and multiple branch pipes communicating with the side of the hollow rotating shaft. Each branch pipe has multiple oblique liquid outlets 12 that are opposite to the cavity wall 6 along the height direction. The oblique liquid outlets can be opened on the side opposite to the cavity wall, so that the flushing water forms a water mist and is sprayed obliquely to the cavity wall. The hollow rotating shaft is provided with a flushing liquid inlet 2.

[0057] The flushing fluid enters the hollow rotating shaft from the flushing fluid inlet 2 and is sprayed obliquely onto the cavity wall 6 through multiple oblique outlets 12 set on the branch pipe to form a water film to remove the deposited salt adhering to the cavity wall. At the same time, the reaction force of flushing the wall drives the flushing assembly to rotate in the cavity to achieve 360-degree treatment of the cavity wall.

[0058] To ensure sufficient contact between materials, in this invention, a material dispersion component connected to the feed inlet 1 is provided around the hollow rotating shaft in the cavity. This component is used to distribute the reactants in the inner area formed by multiple branch pipes, which can, to a certain extent, prevent salts from depositing on the inner wall surface of the reactor.

[0059] In this invention, to improve the rinsing effect, the inclined liquid outlet 12 is inclined downward at 15° to 45° to the cavity wall 6.

[0060] In this invention, multiple oblique liquid outlets 12 are distributed in a sparse-to-dense-to-dense pattern on the branch pipe. Specifically, the distance between two adjacent liquid outlets 12 is distributed in a decreasing arithmetic sequence from top to bottom. The distance between the first and second liquid outlets from top to bottom is a1, the distance between the second and third liquid outlets is a2, and so on, with the distance between the nth and (n+1)th liquid outlets being a... n In some embodiments of the present invention, a1 = 10 mm, a n =a1-(n-1)*0.5mm; Further, from top to bottom, the cross-sectional area of ​​the oblique outlet 12 on each branch pipe gradually increases, and the outlet diameter is distributed in an arithmetic sequence from top to bottom, wherein the diameter of the first outlet is r1, the diameter of the second outlet is r2, ..., the diameter of the nth outlet is r nIn some embodiments of the present invention, r1 = 0.1 mm, r n =r1+(n-1)*0.01mm, which facilitates the dissolution of inorganic salts in the subcritical zone located on the inner wall and lower part of the reaction chamber. In this embodiment of the invention, only 15 oblique outlets on each branch pipe are provided as an example to illustrate the advantages of the invention, but the invention is not limited thereto.

[0061] In this invention, the feed inlet 1 extends into the cavity to form a feed pipe 7. To ensure sufficient contact between the reactants, a hollow rotating shaft is fitted inside the feed pipe 7, with its top opening serving as a rinsing liquid inlet 2 and extending upwards beyond the feed pipe 7 for separate feeding. The annular gap formed between the bottom end of the feed pipe 7 and the hollow rotating shaft serves as a nozzle structure 8, which acts as a material dispersion component. The nozzle structure can be a commonly used nozzle structure in the prior art, such as a multi-point shower-like nozzle. This invention has no special requirements for this type and will not describe it in detail. After further atomization and uniform mixing through the nozzle structure, the material is sprayed into the supercritical reaction core area for complete reaction.

[0062] In this invention, the rinsing assembly is configured as a stirring paddle structure 10, the stirring shaft 9 of the stirring paddle structure 10 is formed as a hollow rotating shaft, and the paddle blade 11 of the stirring paddle structure 10 is formed as a branch pipe.

[0063] This invention can add commonly used components from the prior art as needed, such as control valves for feed inlets, rinsing liquid inlets, or solid-liquid product outlets, and commonly used temperature and pressure detection elements from the prior art in the reaction apparatus. This invention has no special requirements for these, and will not describe them in detail.

[0064] Another aspect of the present invention provides a supercritical water oxidation reaction method for treating organic waste liquid, the method being carried out in the supercritical water oxidation reaction apparatus of the present invention, and comprising the following:

[0065] A mixture containing organic waste liquid and oxidant is introduced into feed inlet 1. The mixture reacts under supercritical water oxidation conditions to obtain gaseous products and solid products containing deposited salts adhering to the cavity wall.

[0066] Simultaneously, flushing fluid is fed into the flushing fluid inlet 2. The flushing fluid enters the hollow rotating shaft and is sprayed obliquely onto the cavity wall 6 through multiple oblique outlets 12 set on the branch pipe, causing the flushing assembly to rotate and remove the deposited salt adhering to the cavity wall.

[0067] The solid product containing inorganic salts is redissolved in the subcritical region to form a solid-liquid product, which is discharged from the solid-liquid product outlet 4, and the gaseous product is discharged from the gaseous product outlet.

[0068] In this invention, the heat generated by the supercritical water oxidation reaction in the front stage is used to preheat the mixture of subsequent feed materials and provide reaction conditions for the subsequent supercritical water oxidation reaction, so as to realize the simultaneous completion of cold feed preheating and reaction, thereby improving processing efficiency.

[0069] In this invention, the material introduced through the feed inlet 1 is dispersed into the reaction chamber by the material dispersion component.

[0070] In this invention, the reaction conditions for the supercritical water oxidation reaction include: a temperature of 375–620°C, preferably 395–560°C; and a pressure of 22–31 MPa, preferably 22–28 MPa.

[0071] According to a preferred embodiment of the present invention, the method of the present invention includes:

[0072] Preferably, the method includes:

[0073] 1) Provide supercritical water oxidation reaction conditions through fuel combustion: preheated fuel is introduced into the material inlet, and the fuel burns and releases heat in the reaction chamber to form a supercritical reaction zone that can provide supercritical water oxidation reaction conditions for step 2).

[0074] The supercritical reaction zone is surrounded by a subcritical zone with a lower temperature. The subcritical zone is used to dissolve the inorganic salts produced by the supercritical oxidation reaction.

[0075] 2) Supercritical water oxidation reaction: The fuel introduced into the material inlet is switched to a mixture containing organic waste liquid and oxidant. The mixture undergoes supercritical water oxidation reaction in the supercritical reaction zone to obtain gaseous products and solid products containing inorganic salts attached to the reaction chamber wall.

[0076] In this invention, preferably, the preheating temperature of the fuel is 350–373°C.

[0077] While the mixture is introduced, flushing liquid is fed into the flushing liquid inlet 2. The flushing liquid enters the hollow rotating shaft and is sprayed obliquely onto the cavity wall 6 through multiple inclined outlets 12 set on the branch pipe, causing the flushing assembly to rotate and remove the deposited salt adhering to the cavity wall. The solid phase product after the reaction settles to the lower subcritical zone by its own weight and then dissolves to form a concentrated salt liquid phase product, which is discharged from the lower solid-liquid product outlet. A small amount of solid phase product adhering to the low-temperature subcritical inner wall of the reactor is dissolved into a salt solution through the swirling liquid film formed by the flushing liquid and then flows to the lower solid-liquid product outlet for discharge. The gas phase product is discharged from the gas phase product outlet.

[0078] In this invention, the rinsing solution is selected from water or an aqueous solution of sodium bicarbonate.

[0079] In this invention, the fuel is selected from at least one of methanol aqueous solution, ethanol aqueous solution or isopropanol aqueous solution. In the embodiments of this invention, only a fuel with a COD of 20000 mg / L is used as an example to illustrate the advantages of this invention, but this invention is not limited thereto.

[0080] In this invention, the organic waste liquid comes from coal chemical or petrochemical sources.

[0081] In this invention, the organic waste liquid is selected from one or more mixtures of high-concentration organic wastewater, high-salt organic wastewater, and mixed-salt organic mother liquor.

[0082] The main components of the organic waste liquid of this invention include: phenols, quinolines, pyridines, benzenes and their derivatives.

[0083] In this invention, the concentration of high-concentration organic waste liquid is ≥5000mg / L COD content.

[0084] In this invention, the salt content (TDS) of the high-salt organic waste liquid is ≥5000 mg / L.

[0085] In this invention, the oxidant is selected from one or more of air, oxygen and hydrogen peroxide.

[0086] In this invention, the mixture also includes a combustion aid and a regulator. The regulator keeps the pH value of the resulting wastewater at around 7, and the mass fraction of organic matter in the regulated wastewater is maintained at 2-3%, so that the heat released by combustion can achieve self-heating of the system.

[0087] In this invention, preferably, the combustion aid includes a combustion-supporting organic solvent; more preferably, the combustion-supporting organic solvent is selected from at least one of ethanol, isopropanol, or methanol.

[0088] In this invention, preferably, the regulator is selected from water, alkaline solution and acidic solution.

[0089] According to a preferred embodiment of the present invention, the supercritical water oxidation reaction is carried out in the presence of a catalyst, which is selected from homogeneous catalysts and / or heterogeneous catalysts.

[0090] In this invention, preferably, the homogeneous catalyst is selected from one or more of sodium hydroxide, soluble transition metal salts, basic salts, and heteropolyacids.

[0091] In this invention, more preferably, the soluble transition metal salt includes nitrates and / or sulfates, wherein the soluble transition metal salt comprises at least one of Cu, Fe, Mn, Ni and Co.

[0092] In this invention, preferably, the alkaline salt includes sodium carbonate and / or sodium bicarbonate, wherein the alkaline solution is a commonly used alkaline solution, such as NaOH, Na2CO3, or NaHCO3; and the acidic solution is a commonly used acidic solution, such as HCl, H2SO4, or H2CO3. This invention does not have any special requirements for this and will not be described in detail.

[0093] In this invention, preferably, the heteropolyacid includes at least one of phosphotungstic acid, silicotungstic acid, and phosphomolybdic acid.

[0094] In this invention, the active component of the heterogeneous catalyst is selected from one or more of noble metal elements, activated carbon, and metal oxides.

[0095] In this invention, preferably, the noble metal element includes at least one of Pt, Pd, Rh, Ru and Ag.

[0096] In this invention, preferably, the metal oxide includes one or more of MgO, NiO, MnO2 and Cr2O3.

[0097] The supported catalyst in this invention includes CeO2 or MnO2-ZrO2.

[0098] According to the present invention, it is understood that during the supercritical water oxidation reaction of the present invention, the reaction is an exothermic reaction, that is, the supercritical reaction zone is formed by exothermic reaction. As the reaction proceeds, the temperature of the reaction system will continuously increase in the early stage of the reaction until the supercritical reaction zone is formed stably. Other areas in the cavity are subcritical zones. Those skilled in the art can control the reaction temperature to 375-620°C using conventional technical means in the art, which will not be elaborated here.

[0099] The advantages of the present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0100] The following examples are as follows Figure 1 The supercritical water oxidation reaction is carried out in the apparatus shown. The apparatus includes a shell 5 and a cavity formed by the shell. The top of the shell is provided with a feed port 1 and a gaseous product outlet 3 that communicate with the cavity. The bottom of the shell is opened to form a gradually narrowing solid-liquid product outlet 4.

[0101] A flushing assembly is installed in the cavity. The flushing assembly is configured as a stirring paddle structure 10. The stirring shaft 9 of the stirring structure is configured as a hollow rotating shaft that is rotatably connected to the housing 5. The top opening of the hollow rotating shaft passes through the top of the housing and forms a flushing liquid inlet 2. The top is closed and the side is connected to multiple blades 11. The blades 11 are also configured as branch pipes that can flow flushing liquid. Each branch pipe extends along the height direction and has multiple oblique liquid outlets 12 opposite to the cavity wall 6 along the extension direction. The stirring shaft 9 is fitted with a feed pipe 7 that passes through the top of the housing. The top of the annular gap formed between the feed pipe and the hollow rotating shaft is configured as a feed inlet 1, and the bottom is configured as a nozzle structure 8.

[0102] The method includes: 1) introducing preheated fuel into the feed inlet 1, where the fuel comes into contact with oxygen in the cavity and burns, releasing heat to form a supercritical reaction zone 13 that can provide supercritical water oxidation reaction conditions for step 2);

[0103] 2) Switch the fuel introduced into inlet 1 to a mixture containing organic waste liquid and oxidant, and at the same time introduce flushing liquid into flushing liquid inlet 2.

[0104] Example 1

[0105] like Figure 1 As shown, a preheated methanol-water solution with a COD of 20000 mg / L at 353°C is injected into the chamber through the feed inlet 1 and the nozzle structure 8, where it comes into contact with oxygen in the chamber and undergoes a supercritical water oxidation reaction. At the same time, heat is released to form a supercritical reaction zone 13. The pressure at the feed inlet is 22-25 MPa and the temperature is 350°C.

[0106] The exothermic oxidation of the fuel creates a supercritical reaction zone 13 in the upper part of the cavity, with a reaction temperature of 450–550°C and a pressure of 22–25 MPa.

[0107] Then the feed is switched to organic wastewater from catalyst production in petrochemical enterprises (wastewater COD is 5000 mg / L, TDS is 10000 mg / L) and a mixture of hydrogen peroxide solution as oxidant, isopropanol as combustion aid and sodium bicarbonate as regulator. After adjustment, the pH value of the mixture is kept at about 7 and the mass fraction of organic matter is kept at about 3%. The mixture is sprayed into the supercritical reaction zone 13 through the feed pipe 7 and the nozzle structure 8, where a supercritical water oxidation reaction occurs, forming gaseous reaction products and solid-liquid reaction products and releasing heat.

[0108] Simultaneously, a stream of water is introduced into the inlet pipe 2, passes through the hollow stirring shaft 9 to the impeller 11, and forms a water mist through the inclined outlet 12. The water mist is then sprayed obliquely onto the cavity wall 6 to form a water film. The reaction force drives the stirring impeller structure 10 to rotate, thereby removing the deposited salt attached to the cavity wall 6. The inclined outlet is at a 30° angle downwards from the cavity wall. Each branch pipe has 15 inclined outlets, which are distributed sparsely at the top and densely at the bottom. From top to bottom, the distance between the first and second outlets is a1, which is 10 mm; the distance between the second and third outlets is a2, which is 9.5 mm, and so on. From top to bottom, the cross-sectional area of ​​the inclined outlets on each impeller 11 gradually increases. The aperture of the first outlet is r1, which is 0.1 mm; the aperture of the second outlet is r2, which is 0.11 mm, and so on.

[0109] The gaseous product after the reaction rises to the top outlet 3 and is discharged from the system; the solid product after the reaction sinks to the lower subcritical zone in the reactor by its own weight and then dissolves to form a concentrated salt liquid product, which is discharged from the lower solid-liquid product outlet 4; in this embodiment, the catalyst is selected from copper sulfate.

[0110] The final treatment result is that the TDS content in the condensate (referring to demineralized water with essentially COD removed) after condensation of the gas phase outlet product is 10 mg / L, and the chemical oxygen demand (COD) is... Cr The content is 0 mg / L, the TDS of the bottom solid-liquid product outlet material is 150,000 mg / L, and the COD is 0 mg / L. Cr The content is 0 mg / L.

[0111] Example 2

[0112] like Figure 1 As shown, a fuel isopropanol aqueous solution with a COD of 20000 mg / L, preheated to 360℃, is injected into the cavity through the feed inlet 1 and the nozzle structure 8, and comes into contact with the oxygen in the cavity to undergo a supercritical water oxidation reaction. At the same time, heat is released to form a supercritical reaction zone 13. The pressure at the feed inlet is 22-25 MPa and the temperature is 350℃.

[0113] The exothermic oxidation of the fuel creates a supercritical reaction zone 13 in the upper part of the cavity, with a reaction temperature of 450–550°C and a pressure of 22–25 MPa.

[0114] Then the feed is switched to ethylene alkali residue wastewater from petrochemical enterprises (COD is 10000 mg / L, TDS is 25000 mg / L) and a mixture of oxygen as oxidant, isopropanol as combustion aid and water as regulator (after adjustment, the pH value of the mixture is around 7 and the mass fraction of organic matter is maintained at around 3%). It is sprayed into the supercritical reaction zone 13 through the feed pipe 7 and the nozzle structure 8, where a supercritical water oxidation reaction occurs, forming gaseous reaction products and solid-liquid reaction products and releasing heat.

[0115] Simultaneously, a stream of water is introduced into the inlet pipe 2, passes through the hollow stirring shaft 9 to the impeller 11, and forms a water mist through the inclined outlet 12. The water mist is then sprayed obliquely onto the cavity wall 6 to form a water film. The reaction force drives the stirring impeller structure 10 to rotate, thereby removing the deposited salt attached to the cavity wall 6. The inclined outlet is at a 20° angle downwards from the cavity wall. Each branch pipe has 15 inclined outlets, which are distributed sparsely at the top and densely at the bottom. From top to bottom, the distance between the first and second outlets is a1, which is 10 mm; the distance between the second and third outlets is a2, which is 9.5 mm, and so on. From top to bottom, the cross-sectional area of ​​the inclined outlets on each impeller 11 gradually increases. The aperture of the first outlet is r1, which is 0.1 mm; the aperture of the second outlet is r2, which is 0.11 mm, and so on.

[0116] The gaseous product after the reaction rises to the top outlet 3 and is discharged from the system; the solid product after the reaction sinks to the lower subcritical zone in the reactor by its own weight and then dissolves to form a concentrated salt liquid product, which is discharged from the lower solid-liquid product outlet 4; in this embodiment, the catalyst is selected from sodium carbonate.

[0117] The final treatment results are as follows: the TDS content in the condensate (referring to the demineralized water with basically removed COD) after condensation of the gas phase outlet product is 10 mg / L, the COD content is 0 mg / L, and the TDS and COD content of the bottom solid-liquid product outlet material are 200,000 mg / L and 0 mg / L, respectively.

[0118] Example 3

[0119] like Figure 1 As shown, a fuel isopropanol aqueous solution with a COD of 20000 mg / L, preheated to 360℃, is injected into the cavity through the feed inlet 1 and the nozzle structure 8, and comes into contact with the oxygen in the cavity to undergo a supercritical water oxidation reaction. At the same time, heat is released to form a supercritical reaction zone 13. The pressure at the feed inlet is 22-25 MPa and the temperature is 350℃.

[0120] The exothermic oxidation of the fuel creates a supercritical reaction zone 13 in the upper part of the cavity, with a reaction temperature of 450–550°C and a pressure of 22–25 MPa.

[0121] Then the feed is switched to a mixture of refractory evaporation mother liquor from the end of water treatment in a coal chemical enterprise (COD of 20,000 mg / L and TDS of 50,000 mg / L) and an oxidant of hydrogen peroxide solution, a combustion aid of ethanol, and a regulator of sodium bicarbonate (adjusted to make the pH of the mixture around 7 and the mass fraction of organic matter around 3%). The mixture is then sprayed into the supercritical reaction zone 13 through the feed pipe 7 and the nozzle structure 8, where a supercritical water oxidation reaction occurs, forming gaseous reaction products and solid-liquid reaction products and releasing heat.

[0122] Simultaneously, an aqueous solution of sodium bicarbonate is introduced into the inlet pipe 2, passes through the hollow stirring shaft 9 to the impeller 11, and forms a water mist through the inclined outlet 12. This mist is then sprayed obliquely onto the cavity wall 6 to form a water film, and the reaction force drives the stirring impeller structure 10 to rotate, thereby removing the deposited salt adhering to the cavity wall 6. The inclined outlet is at a 45° angle downwards from the cavity wall. Each branch pipe has 15 inclined outlets, which are distributed sparsely at the top and densely at the bottom. From top to bottom, the distance between the first and second outlets is a1, which is 10 mm; the distance between the second and third outlets is a2, which is 9.5 mm, and so on. From top to bottom, the cross-sectional area of ​​the inclined outlets on each impeller 11 gradually increases. The aperture of the first outlet is r1, which is 0.1 mm; the aperture of the second outlet is r2, which is 0.11 mm, and so on.

[0123] The gaseous product after the reaction rises to the top outlet 3 and is discharged from the system; the solid product after the reaction sinks to the lower subcritical zone in the reactor by its own weight and then dissolves to form a concentrated salt liquid product, which is discharged from the lower solid-liquid product outlet 4; in this embodiment, the heterogeneous catalyst active component is selected from Ru.

[0124] The final treatment result is that the TDS content in the condensate (referring to demineralized water with essentially COD removed) after condensation of the gas phase outlet product is 10 mg / L, and the chemical oxygen demand (COD) is... Cr The content is 0 mg / L, the TDS of the bottom solid-liquid product outlet material is 250,000 mg / L, and the COD is 0 mg / L. Cr The content is 0 mg / L.

[0125] Example 4

[0126] Unlike Example 1, the inclined liquid outlets are horizontally arranged and have the same cross-sectional area, and multiple inclined liquid outlets are evenly distributed on the branch pipe.

[0127] The final treatment result is that the TDS content in the condensate (referring to demineralized water with essentially COD removed) after condensation of the gas phase outlet product is 250 mg / L, and the chemical oxygen demand (COD) is... CrThe content is 350 mg / L, the TDS of the bottom solid-liquid product outlet material is 45000 mg / L, and the COD is... Cr The content is 450 mg / L.

[0128] Comparative Example 1

[0129] Unlike Example 1, this study uses a conventional tubular reactor from the prior art in a saline wastewater treatment system and method disclosed in CN110963557A. Example 2 of this system shows that after treating saline wastewater with a TDS value of 30000 mg / L and a COD value of 1000 mg / L, the final treated gaseous effluent (referring to demineralized water with essentially removed COD) contains low TDS and low COD. Cr The content was not specified; the TDS of the bottom solid-liquid product outlet material was 200,000 mg / L, and the COD was... Cr The content is 0 mg / L.

[0130] The comparison shows that the COD concentration of the treated wastewater is lower, and the salt concentration rate is also lower (only 6.67 times concentrated).

[0131] This invention enables efficient degradation of COD in high-concentration organic waste liquid and simultaneous salt concentration, achieving reduction, harmlessness and resource utilization of high-concentration organic waste liquid, effectively preventing salt deposition and blockage, improving operational safety, and reducing equipment cost and operating cost.

[0132] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A supercritical water oxidation reactor for treating organic waste liquid, characterized in that, The supercritical water oxidation reactor includes a shell (5) and a cavity formed by the shell (5). The shell (5) is provided with a feed inlet (1), a gas phase product outlet (3) and a solid-liquid product outlet (4) that communicate with the cavity. The cavity is used to induce supercritical water oxidation of organic waste liquid to obtain gaseous products and solid products including deposited salts adhering to the cavity wall (6). The cavity is equipped with a flushing assembly, which includes a hollow rotating shaft rotatably connected to the housing (5) and multiple branch pipes communicating with the side of the hollow rotating shaft. Each branch pipe has multiple oblique liquid outlets (12) opposite to the wall (6) of the cavity along the height direction. The hollow rotating shaft is provided with a flushing liquid inlet (2). The flushing fluid enters the hollow rotating shaft from the flushing fluid inlet (2) and is sprayed obliquely onto the cavity wall (6) through multiple oblique outlets (12) set on the branch pipe to form a water film to remove the deposited salt adhering to the cavity wall. At the same time, the flushing assembly is driven to rotate by the reaction force of flushing the wall.

2. The supercritical water oxidation device according to claim 1, characterized in that, The cavity is provided with a material dispersion component that communicates with the feed port (1) around the hollow rotating shaft, so that the reactant is distributed in the inner area formed by the multiple branch pipes. The inclined liquid outlet (12) is inclined downward at 15°~45° to the cavity wall (6); The multiple oblique liquid outlets (12) are distributed sparsely at the top and densely at the bottom on the branch pipe; From top to bottom, the cross-sectional area of ​​the oblique outlet (12) on each of the branch pipes gradually increases.

3. The supercritical water oxidation device according to claim 2, characterized in that, The feed inlet (1) extends into the cavity to form a feed pipe (7), the hollow rotating shaft is sleeved in the feed pipe (7), and the annular gap formed between the bottom end of the feed pipe (7) and the hollow rotating shaft is set as a nozzle structure (8), and the nozzle structure (8) is formed as the material dispersion component.

4. The supercritical water oxidation device according to claim 1, characterized in that, The flushing assembly is configured as a stirring paddle structure (10), the stirring shaft (9) of the stirring paddle structure (10) is formed as the hollow rotating shaft, and the paddle blade (11) of the stirring paddle structure (10) is formed as the branch pipe.

5. A supercritical water oxidation method for treating organic waste liquid, characterized in that, The method is carried out in the supercritical water oxidation reactor according to any one of claims 1-4, and includes the following: A mixture containing organic waste liquid and oxidant is introduced into the feed inlet (1), and the mixture is reacted under supercritical water oxidation reaction conditions to obtain gaseous products and solid products containing deposited salts attached to the cavity wall. At the same time, flushing liquid is fed into the flushing liquid inlet (2), and the flushing liquid enters the hollow rotating shaft. It is then sprayed obliquely onto the cavity wall (6) through multiple oblique outlets (12) set on the branch pipe, causing the flushing assembly to rotate and remove the deposited salt adhering to the cavity wall. The solid product containing inorganic salts is redissolved in the subcritical region to form a solid-liquid product, which is discharged from the solid-liquid product outlet (4), and the gaseous product is discharged from the gaseous product outlet.

6. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, The method includes: 1) Provide supercritical water oxidation reaction conditions through fuel combustion: preheated fuel is introduced into the feed port (1), and the fuel is combusted in contact with oxygen in the cavity, releasing heat to form a supercritical reaction zone (13) that can provide the supercritical water oxidation reaction conditions for step 2). The supercritical reaction zone (13) is surrounded by a subcritical zone with a lower temperature, which is used to dissolve the inorganic salts produced by the supercritical oxidation reaction. 2) Supercritical water oxidation reaction: The fuel introduced into the feed port (1) is switched to a mixture containing organic waste liquid and oxidant, which undergoes the supercritical water oxidation reaction in the supercritical reaction zone (13).

7. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, Material is introduced into the feed inlet (1) and dispersed into the cavity through the material dispersion component.

8. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, The supercritical water oxidation reaction conditions include: a temperature of 375~620℃ and a pressure of 22~31MPa.

9. The supercritical water oxidation method for treating organic waste liquid according to claim 8, wherein, The supercritical water oxidation reaction conditions include: a temperature of 395~560℃ and a pressure of 22~28Mpa.

10. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, The rinsing solution is selected from water or an aqueous solution of sodium bicarbonate; The fuel is selected from at least one of methanol aqueous solution, ethanol aqueous solution or isopropanol aqueous solution; The preheating temperature of the fuel is 350~373℃; The organic waste liquid comes from coal chemical or petrochemical industries; The organic waste liquid is selected from one or more mixtures of high-concentration organic wastewater, high-salt organic wastewater, and mixed-salt organic mother liquor; The oxidant is selected from oxygen-containing gases and / or hydrogen peroxide.

11. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, The mixture also includes combustion improvers and modifiers.

12. The supercritical water oxidation method for treating organic waste liquid according to claim 11, wherein, The combustion aid includes a combustion-supporting organic solvent; more preferably, the combustion-supporting organic solvent is selected from at least one of ethanol, isopropanol, or methanol.

13. The supercritical water oxidation method for treating organic waste liquid according to claim 11, wherein, The regulator is selected from water, alkaline solution, and acidic solution.

14. The supercritical water oxidation method for treating organic waste liquid according to claim 5, wherein, The supercritical water oxidation reaction is carried out in the presence of a catalyst, which is selected from homogeneous catalysts and / or heterogeneous catalysts.

15. The supercritical water oxidation method for treating organic waste liquid according to claim 14, wherein, The homogeneous catalyst is selected from one or more of sodium hydroxide, soluble transition metal salts, basic salts, and heteropolyacids.

16. The supercritical water oxidation method for treating organic waste liquid according to claim 15, wherein, The soluble transition metal salt includes nitrates and / or sulfates, and the soluble transition metal comprises at least one of Cu, Fe, Mn, Ni and Co; 17. The supercritical water oxidation method for treating organic waste liquid according to claim 15, wherein, The alkaline salts include sodium carbonate and / or sodium bicarbonate.

18. The supercritical water oxidation method for treating organic waste liquid according to claim 15, wherein, The heteropolyacids include at least one of phosphotungstic acid, silicotungstic acid, and phosphomolybdic acid.

19. The supercritical water oxidation method for treating organic waste liquid according to claim 14, wherein, The active component of the heterogeneous catalyst is selected from one or more of noble metal elements, activated carbon, and metal oxides.

20. The supercritical water oxidation method for treating organic waste liquid according to claim 19, wherein, The noble metal element includes at least one of Pt, Pd, Rh, Ru, and Ag.

21. The supercritical water oxidation method for treating organic waste liquid according to claim 19, wherein, The metal oxide includes one or more of MgO, NiO, MnO2, and Cr2O3.

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