Continuous wet oxidation device and process for enhanced mass transfer treatment of high-salinity organic wastewater

Abstract

The invention relates to a continuous wet oxidation device for enhanced mass transfer treatment of high-salinity organic wastewater. The continuous wet oxidation device comprises a wastewater storage tank, a liquid inlet system, a high-pressure oxygen storage tank, a gas inlet system, a mass transfer enhanced reactor, a gas-liquid separation system and an oxygen recovery system, the mass transfer enhanced reactor is of a shell-and-tube structure and comprises a reactor shell and a built-in ceramic distributor; a tube pass is formed in the ceramic distributor, and a shell pass is formed between the ceramic distributor and the reactor shell; the tube pass is provided with a liquid feeding port and a liquid discharging port, and the shell pass is provided with a gas feeding port. Oxygen is distributed to a tube pass through the ceramic distributor and is quickly dispersed into micron-sized bubbles, so that the contact area between gas and liquid is increased, and the oxygen utilization rate and the reaction efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of high-salt organic wastewater treatment technology, and in particular to a continuous wet oxidation device and process for enhanced mass transfer treatment of high-salt organic wastewater. Background Technology

[0002] Industrial production often involves processes involving salty materials, salt leaching, or salt generation, leading to the production of high-salinity wastewater. With the acceleration of industrialization and the continuous expansion of industries such as petrochemicals, coal chemicals, power and heat, and pharmaceuticals, the discharge of high-salinity organic wastewater has increased dramatically. High-salinity organic wastewater refers to wastewater with a total salt content exceeding 1%, or a total dissolved solids (TDS) mass fraction ≥ 3.5%, containing, in addition to sodium (Na+). + Ca 2+ K + Cl － SO4 2－ In addition to various anions and cations, it also contains other types of recalcitrant organic pollutants, characterized by complex composition, large volume, poor biodegradability, and high toxicity. Direct or diluted discharge will damage the environment, causing eutrophication of rivers and lakes, and in severe cases, accelerating desertification and salinization, reducing soil agricultural productivity, affecting the normal reproduction and growth of plants and animals, and negatively impacting human health.

[0003] Currently, the mainstream methods for treating high-salinity organic wastewater include biochemical methods, adsorption methods, coagulation and sedimentation methods, and catalytic wet oxidation methods. Biochemical methods have lower operating costs, but because the high-salinity environment is unfavorable for microbial growth, multiple methods are often used in combination, resulting in complex processes. This significantly reduces treatment efficiency when treating wastewater with high biotoxicity. Adsorption methods have a high removal rate for color, but their effect on substances such as COD is not significant. Coagulation and sedimentation methods require large amounts of chemical reagents and easily generate sludge. Catalytic wet oxidation, a type of advanced oxidation method, uses air or oxygen as an oxidant under high temperature and pressure conditions, with a catalyst added to lower the activation energy of the reaction. Under liquid-phase conditions, it converts large molecular organic matter in water into inorganic substances such as water and carbon dioxide. It has many advantages, including fast reaction rate, high efficiency, wide application range, and small footprint, and has broad application prospects in the treatment of difficult-to-treat high-salinity organic wastewater. However, high treatment costs and low oxygen utilization rates still restrict the development and promotion of catalytic wet oxidation technology.

[0004] CN101433804B discloses a wet oxidation process and apparatus for gas recirculation, which significantly improves oxygen utilization by recycling unreacted oxygen, reducing the ratio of actual air consumption to theoretical air consumption to below 2. However, it fails to effectively solve the gas-liquid mass transfer problem, resulting in a low single-use oxygen utilization rate. CN108341478B discloses a combination of a hypergravity reactor and a wet oxidation process, overcoming the mass transfer resistance problem in traditional wet oxidation methods. This reduces adsorbent usage by 60%, increases catalytic efficiency by 45%, and improves utilization by 52%. However, the hypergravity reactor requires external energy input, and the apparatus contains high-speed rotating components, which does not utilize the inherent safety features of chemical production.

[0005] Existing technologies suffer from low oxygen utilization rates per cycle. Therefore, achieving high oxygen utilization rates in wet oxidation technology has become an urgent problem to be solved. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention introduces a ceramic gas distributor into the reactor to disperse oxygen into micron-sized bubbles, thereby enhancing the mass transfer effect, improving oxygen utilization and reaction efficiency, and requiring less additional energy input for the mass transfer enhancement component, while ensuring high safety.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a continuous wet oxidation device for enhancing mass transfer treatment of high-salt organic wastewater, the continuous wet oxidation device comprising a wastewater storage tank, a liquid inlet system, a high-pressure oxygen storage tank, an air inlet system, a mass transfer enhancement reactor, a gas-liquid separation system, and an oxygen recovery system;

[0009] The mass transfer enhancement reactor is a shell-and-tube structure, including a reactor shell and a built-in ceramic distributor; the ceramic distributor forms a tube side inside, and the ceramic distributor and the reactor shell form a shell side; the tube side is provided with a liquid inlet and a liquid outlet, and the shell side is provided with a gas inlet;

[0010] The wastewater storage tank is connected to the liquid inlet of the mass transfer enhancement reactor via a liquid inlet system. The high-pressure oxygen storage tank is connected to the gas inlet of the mass transfer enhancement reactor via a gas inlet system. The liquid outlet of the mass transfer enhancement reactor is connected to a gas-liquid separation system. The gas outlet of the gas-liquid separation system is connected to an oxygen recovery system. The oxygen recovery system recovers oxygen to the high-pressure oxygen storage tank.

[0011] This invention uses a ceramic distributor to disperse gas into micron-sized bubbles in the tube body of a shell-and-tube reactor, thereby promoting the oxidation reaction of oxygen with high-salt organic wastewater and improving the single-stage utilization rate of oxygen. Compared with traditional aeration discs, oxygen can pass through a large area in the ceramic distributor, and the resulting micron-sized bubbles are evenly distributed in the tube, resulting in a significant improvement in reaction efficiency.

[0012] As a preferred embodiment of the present invention, the ceramic distributor is tubular.

[0013] Preferably, the ceramic distributor includes a dense layer on the inner wall of the ceramic distributor.

[0014] Preferably, the dense layer is formed by the sol-gel method.

[0015] Preferably, the sol preparation and heat treatment parameters of the sol-gel method can be optimized and selected according to the pore size of the dense layer, and are not further limited here.

[0016] Preferably, the pore size of the dense layer is 50-2000nm, for example, it can be 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 1000nm, 1500nm or 2000nm, etc.

[0017] This invention achieves a balance between reaction efficiency and reaction pressure drop by optimizing the pore size of the dense layer. With a suitable pore size, the reaction can be promoted while maintaining the system pressure drop.

[0018] Preferably, the ceramic distributor is located inside the reactor shell and is arranged along the axial direction of the reactor shell.

[0019] Preferably, the circumferential outer edges at both ends of the ceramic distributor are sealed and fixed to the reactor shell by high-temperature sealing rings.

[0020] Preferably, the high-temperature sealing ring is fixed to the stepped surface of the inner wall of the reactor shell by a flange clamping structure.

[0021] Preferably, the high-temperature sealing ring is made of perfluoroether rubber.

[0022] Preferably, both ends of the ceramic distributor are covered with a glaze sealing layer along the end face to the circumferential outer edge that contacts the high-temperature sealing ring.

[0023] This invention avoids short-circuiting of gas in the reactor by covering both ends of the ceramic distributor with a glaze sealing layer, forcing the gas to pass through the tube via a forced path. All gas entering the reactor must pass through the pre-set microporous channels inside the ceramic distributor, resulting in a uniform distribution of micron-sized bubbles.

[0024] Preferably, the ceramic distributor is made of any one of alumina, zirconium oxide, titanium oxide, and silicon carbide.

[0025] As a preferred technical solution of the present invention, the outer shell of the mass transfer enhancement reactor is provided with at least two temperature-controlled heating jackets.

[0026] This invention, through the setting of a multi-stage temperature-controlled heating jacket, can adjust the reaction temperature in multiple stages according to the changes in the material concentration inside the reactor, thereby improving reaction efficiency.

[0027] Preferably, a gas-phase feed inlet is provided on one side of the bottom of the shell of the mass transfer enhanced reactor.

[0028] Preferably, the mass transfer enhanced reactor has a liquid phase inlet and a liquid phase outlet at both ends of its shell.

[0029] Preferably, the mass transfer enhancement reactor is a gas-liquid co-current upward reactor.

[0030] As a preferred embodiment of the present invention, the liquid inlet system includes a liquid inlet pipeline.

[0031] Preferably, a high-pressure metering pump is installed on the liquid inlet pipeline.

[0032] As a preferred embodiment of the present invention, the air intake system includes an air intake pipe.

[0033] Preferably, a mass flow meter is installed on the air intake pipe.

[0034] Preferably, a pressure reducing valve is installed on the air inlet pipeline between the high-pressure oxygen storage tank and the mass flow meter.

[0035] Preferably, the intake pipe is provided with a parallel intake pipe, and a bypass valve is provided on the parallel intake pipe.

[0036] As a preferred embodiment of the present invention, the gas-liquid separation system includes a gas-liquid separation tank and a product tank.

[0037] Preferably, the liquid phase outlet of the gas-liquid separator is connected to the product tank.

[0038] As a preferred technical solution of the present invention, the oxygen recovery system includes an alkali absorption tower, a low-pressure oxygen storage tank, and an oxygen booster.

[0039] Preferably, the alkali absorption tower is connected to the gas phase outlet of the gas-liquid separation system via a pipeline.

[0040] Preferably, a back pressure valve is provided on the gas outlet pipeline of the gas-liquid separation system.

[0041] Preferably, the low-pressure oxygen storage tank is connected to the alkali absorption tower via a pipeline.

[0042] Preferably, the oxygen booster pressurizes the gas in the low-pressure oxygen storage tank and then recovers it to the high-pressure oxygen storage tank.

[0043] This invention removes unreacted oxygen and acid carried by wastewater through an alkali absorption tower, and pressurizes the recovered oxygen through an oxygen booster, so that the oxygen can be fully recovered and utilized without affecting the effect of the oxidation reaction.

[0044] In a second aspect, the present invention provides a process for treating high-salt organic wastewater using the continuous wet oxidation device described in the first aspect, the process comprising:

[0045] High-salt organic wastewater is mixed with a catalyst and added to a wastewater storage tank. The mixture is then pumped to the bottom of the mass transfer enhanced reactor and enters the tube side of the reactor. Simultaneously, high-pressure pure oxygen is transported from a high-pressure oxygen storage tank to the shell side of the mass transfer enhanced reactor. Under the action of pressure difference, the oxygen is rapidly dispersed into micron-sized bubbles by a ceramic distributor and distributed to the tube side of the mass transfer enhanced reactor. The oxygen reacts with the high-salt organic wastewater to undergo an oxidation reaction. The gas-liquid mixture after the reaction is completed is separated by a gas-liquid separation system. The unreacted oxygen is recovered to the high-pressure oxygen storage tank via an oxygen recovery system.

[0046] Preferably, the high-salt organic wastewater is mixed with the catalyst and then pumped from the wastewater storage tank to the bottom of the mass transfer enhanced reactor via a high-pressure metering pump, entering the reactor tube side.

[0047] Preferably, high-pressure pure oxygen is supplied to the shell side of the mass transfer enhanced reactor after being depressurized by a pressure reducing valve from a high-pressure oxygen storage tank and then transported to the shell side by a mass flow meter with the flow rate controlled.

[0048] Preferably, the unreacted oxygen is deacidified by an alkali absorption tower and then introduced into a low-pressure oxygen storage tank, and then pressurized by an oxygen booster and transported to a high-pressure oxygen storage tank.

[0049] As a preferred technical solution of the present invention, the standard state gas-liquid volume ratio of oxygen to wastewater is 10-40, for example, it can be 10, 15, 20, 25, 30, 35 or 40, etc.

[0050] Preferably, the catalyst comprises a copper metal salt.

[0051] Preferably, the copper metal salt includes any one or a combination of at least two of CuSO4, CuCl2 and Cu(NO3)2.

[0052] Preferably, the catalyst is Cu 2+ The dosage is 1500-3000ppm, for example, it can be 1500ppm, 1800ppm, 2000ppm, 2500ppm or 3000ppm, etc.

[0053] Preferably, the reaction pressure of the oxidation reaction is 3.0-5.0 MPa, for example, it can be 3.0 MPa, 3.5 MPa, 4 MPa, 4.5 MPa or 5.0 MPa.

[0054] Preferably, the reaction temperature of the oxidation reaction is 120-240℃, for example, it can be 120℃, 150℃, 180℃, 200℃, 220℃ or 240℃.

[0055] Preferably, the residence time of the high-salt organic wastewater in the mass transfer enhanced reactor is 60-240 min, for example, it can be 60 min, 80 min, 100 min, 150 min, 200 min or 240 min.

[0056] As a preferred technical solution of the present invention, the average diameter of the micron-sized bubbles is 100-400μm, for example, it can be 100μm, 150μm, 200μm, 250μm, 300μm, 350μm or 400μm, etc.

[0057] Compared with the prior art, the present invention has at least the following beneficial effects:

[0058] (1) The present invention utilizes a ceramic distributor to disperse oxygen into micron-sized bubbles, fully combining the advantages of high mass transfer coefficient and long residence time of micron-sized bubbles, and significantly improving gas-liquid mass transfer efficiency.

[0059] (2) The device of the present invention is a continuous feeding reaction device, which realizes continuous operation of the reaction process and significantly improves the reaction efficiency. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the continuous wet oxidation device provided in Embodiment 1 of the present invention;

[0061] Figure 2 This is a schematic diagram of the fixing method of the ceramic distributor and the shell of the mass transfer enhanced reactor in the continuous wet oxidation device provided in Embodiment 1 of the present invention;

[0062] Figure 3 This is an oxygen micron-sized bubble distribution diagram of the process for treating high-salt organic wastewater provided in the application example of the present invention;

[0063] In the diagram: 1. Wastewater storage tank; 2. High-pressure metering pump; 3. High-pressure oxygen storage tank; 4. Pressure reducing valve; 5. Mass flow meter; 6. Bypass valve; 7. Mass transfer enhanced reactor; 8. Gas-liquid separator; 9. Product tank; 10. Back pressure valve; 11. Alkali absorption tower; 12. Low-pressure oxygen storage tank; 13. Oxygen booster; 7-1. High-temperature sealing ring; 7-2. Fastening bolts; 7-3. Flange end cap; 7-4. Reactor shell; 7-5. Ceramic gas distributor. Detailed Implementation

[0064] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0065] Example 1

[0066] This embodiment provides a continuous wet oxidation device for enhanced mass transfer treatment of high-salt organic wastewater, such as... Figure 1 and Figure 2 As shown, the continuous wet oxidation device includes a wastewater storage tank 1, a high-pressure oxygen storage tank 3, a mass transfer enhancement reactor 7, a gas-liquid separation tank 8, a product tank 9, an alkali absorption tower 11, and a low-pressure oxygen storage tank 12.

[0067] The wastewater storage tank 1 is connected to the liquid inlet of the mass transfer enhancement reactor via an inlet pipe. A high-pressure metering pump 2 is installed on the inlet pipe. The high-pressure oxygen storage tank 3 is connected to the gas inlet of the mass transfer enhancement reactor 7 via an inlet pipe. A pressure reducing valve 4 and a mass flow meter 5 are installed on the inlet pipe. A parallel inlet pipe is provided on the inlet pipe, and a bypass valve 6 is installed on the parallel inlet pipe. The liquid outlet of the mass transfer enhancement reactor 7 is connected to a gas-liquid separator 8. A back pressure valve 10 is installed on the gas outlet pipe of the gas-liquid separation system, and then it is connected to an alkali absorption tower 11. The liquid outlet of the gas-liquid separator 8 is connected to a product tank 9. The alkali absorption tower is connected to a low-pressure oxygen storage tank 12. The gas in the low-pressure oxygen storage tank 12 is recovered to the high-pressure oxygen storage tank 3 via an oxygen booster 13.

[0068] The mass transfer enhanced reactor 7 is a shell-and-tube reactor, including a reactor shell 7-4 and a ceramic distributor 7-5. The ceramic distributor 7-5 includes a dense layer disposed on the inner wall of the ceramic distributor. The circumferential outer edges at both ends of the ceramic distributor are sealed and fixed to the reactor shell 7-4 by high-temperature sealing rings 7-1. The high-temperature sealing rings 7-1 are fixed to the stepped surface of the inner wall of the reactor shell by flange end caps 7-3 and fastening bolts 7-2. Both ends of the ceramic distributor are covered with a glaze sealing layer along the end face to the circumferential outer edge in contact with the high-temperature sealing rings. The reactor shell 7-4 is provided with a multi-segment temperature-controlled heating jacket. The reactor shell is provided with a pressure sensor and a thermocouple for monitoring the reaction pressure and temperature.

[0069] Comparative Example 1

[0070] This comparative example provides a continuous wet oxidation apparatus, which is identical to that of Example 1 except that a ceramic distributor is not installed inside the reactor.

[0071] Comparative Example 2

[0072] This comparative example provides a continuous wet oxidation device, which is the same as that in Example 1 except that the ceramic distributor inside the reactor is replaced with a diffuser aeration disc.

[0073] Application Example 1

[0074] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size ZrO2 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 18% sodium chloride and has a TOC of 10520ppm. A CuSO4 catalyst is added at 2000ppm (Cu... 2+ After mixing with wastewater, the liquid feed flow rate is controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature is maintained at 180℃, the gas-liquid ratio is 20, and the residence time is 120 min. Oxygen enters the shell side of the reactor and, under the influence of pressure difference, is dispersed into micron-sized bubbles with an average diameter of 127 μm by the micro-nano channels of the ceramic distributor. The distribution of the micron-sized bubbles in the system is as follows: Figure 3 As shown, micron-sized bubbles react rapidly with epichlorohydrin wastewater, resulting in a TOC of 4.8 ppm in the treated wastewater, achieving a TOC removal rate of 99.95%.

[0075] Application Example 2

[0076] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with an Al₂O₃ ceramic distributor with a pore size of 200 nm. The ceramic distributor is a single-channel device with an inner diameter of 2 cm, an outer diameter of 3 cm, and a length of 100 cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50 sccm using a mass flow meter. The system pressure is stabilized to 4.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 18% sodium chloride and has a TOC of 9582 ppm. A CuCl₂ catalyst is added at 1500 ppm (based on CuCl₂ concentration). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 158 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 6.7 ppm, achieving a TOC removal rate of 99.93%.

[0077] Application Example 3

[0078] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a TiO2 ceramic distributor with a pore size of 2000 nm. The ceramic distributor is single-channel, with an inner diameter of 2 cm, an outer diameter of 3 cm, and a length of 100 cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50 sccm using a mass flow meter. The system pressure is stabilized to 4.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 17% sodium chloride and has a TOC of 9570 ppm. A CuSO4 catalyst is introduced at 2200 ppm (based on Cu...). 2+ After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 337 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 10.5 ppm, achieving a TOC removal rate of 99.89%.

[0079] Application Example 4

[0080] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size SiC ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 3.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50sccm using a mass flow meter. The system pressure is stabilized to 3.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 20% sodium chloride and has a TOC of 9478ppm. The CuCl2 catalyst is introduced at 2800ppm (CuCl2 is used as the catalyst in the process). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 134 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 9.3 ppm, achieving a TOC removal rate of 99.90%.

[0081] Application Example 5

[0082] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a TiO2 ceramic distributor with a pore size of 50 nm. The ceramic distributor is single-channel, with an inner diameter of 2 cm, an outer diameter of 3 cm, and a length of 100 cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 5.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50 sccm using a mass flow meter. The system pressure is stabilized to 5.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 19% sodium chloride and has a TOC of 10478 ppm. The Cu(NO3)2 catalyst is introduced at 3000 ppm (using Cu... 2+ After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 118 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 2.1 ppm, achieving a TOC removal rate of 99.98%.

[0083] Application Example 6

[0084] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size ZrO2 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the back pressure valve opening. The epichlorohydrin wastewater contains 19% sodium chloride and has a TOC of 9978ppm. The Cu(NO3)2 catalyst is introduced at 1700ppm (based on Cu...). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 120℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 128 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 7.5 ppm, with a TOC removal rate of 99.92%.

[0085] Application Example 7

[0086] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size Al2O3 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 18% sodium chloride and has a TOC of 10213ppm. A CuCl2 catalyst is added at 2100ppm (CuCl2 is used as the catalyst in the process). 2+ After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 240℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 125 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 2.4 ppm, achieving a TOC removal rate of 99.98%.

[0087] Application Example 8

[0088] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size SiC ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 100sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 20% sodium chloride and has a TOC of 10782ppm. A CuCl2 catalyst is introduced at 2600ppm (CuCl2 is used as the catalyst in the process). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 300 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 60 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 129 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 47.6 ppm, with a TOC removal rate of 99.56%.

[0089] Application Example 9

[0090] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size ZrO2 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 25sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 18% sodium chloride and has a TOC of 9872ppm. A CuSO4 catalyst is introduced at 2300ppm (CuSO4 is used as the catalyst in the process). 2+ After being mixed with the wastewater, the liquid feed flow rate was controlled at 75 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 240 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 122 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. No TOC was detected in the treated epichlorohydrin wastewater, achieving a TOC removal rate of 100%.

[0091] Application Example 10

[0092] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 50nm pore size Al2O3 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 25sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 17% sodium chloride and has a TOC of 9987ppm. The CuCl2 catalyst is introduced at 2700ppm (CuCl2 is used as the catalyst in the process). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 10, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 129 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 34.9 ppm, with a TOC removal rate of 99.65%.

[0093] Application Example 11

[0094] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a ZrO2 ceramic distributor with a pore size of 50 nm. The ceramic distributor is a single-channel device with an inner diameter of 2 cm, an outer diameter of 3 cm, and a length of 100 cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 100 sccm using a mass flow meter. The system pressure is stabilized at 4.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 18% sodium chloride and has a TOC of 10428 ppm. The Cu(NO3)2 catalyst is introduced at 2000 ppm (using Cu... 2+ After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 160℃, the gas-liquid ratio at 40, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 132 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 0.8 ppm, achieving a TOC removal rate of 99.99%.

[0095] Application Example 12

[0096] This application example provides a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Example 1. The reactor is equipped with a 100μm pore size Al2O3 ceramic distributor. The ceramic distributor is single-channel, with an inner diameter of 2cm, an outer diameter of 3cm, and a length of 100cm. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50sccm using a mass flow meter. The system pressure is stabilized to 4.0MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 20% sodium chloride and has a TOC of 10078ppm. The CuCl2 catalyst is introduced at 2900ppm (CuCl2 is used as the catalyst in the process). 2+After being mixed with the wastewater, the liquid feed flow rate was controlled at 150 mL / min using a high-pressure metering pump. The reaction temperature was maintained at 180℃, the gas-liquid ratio at 20, and the residence time at 120 min. Oxygen entered the shell side of the reactor and, under the influence of pressure difference, was dispersed into micron-sized bubbles with an average diameter of 1400 μm by the micro-nano channels of the ceramic distributor, reacting rapidly with the epichlorohydrin wastewater. The treated epichlorohydrin wastewater had a TOC of 26.7 ppm, with a TOC removal rate of 99.74%.

[0097] Application Comparative Example 1

[0098] This application provides a comparative example of a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Comparative Example 1. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50 sccm using a mass flow meter. The system pressure is stabilized at 4.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 17% sodium chloride and has a TOC of 9785 ppm. The CuSO4 catalyst is introduced at 2200 ppm (using CuSO4 as the catalyst). 2+ After the (calculated) concentration is mixed with the wastewater, the liquid phase feed flow rate is controlled at 150 mL / min by a high-pressure metering pump, the reaction temperature is controlled at 180℃, the gas-liquid ratio is 20, the residence time is 120 min, and oxygen enters the reactor from the bottom to react with the epichlorohydrin wastewater. The TOC of the treated epichlorohydrin wastewater is 145.3 ppm, and the TOC removal rate is 98.52%.

[0099] Application Comparative Example 2

[0100] This application provides a comparative example of a process for treating high-salt organic wastewater using the continuous wet oxidation device provided in Comparative Example 2. After pressure and leak testing, oxygen is introduced by opening the gas valve. Once the pressure reaches 4.0 MPa, the bypass valve is closed, and the oxygen flow rate is controlled at 50 sccm using a mass flow meter. The system pressure is stabilized at 4.0 MPa by controlling the opening of the back pressure valve. The epichlorohydrin wastewater contains 17% sodium chloride and has a TOC of 10875 ppm. The liquid feed flow rate is controlled at 150 mL / min using a high-pressure metering pump, the reaction temperature is controlled at 180℃, the gas-liquid ratio is 20, and the residence time is 120 min. The Cu(NO3)2 catalyst is introduced at 2600 ppm (Cu... 2+ After the oxygen concentration (calculated) is mixed with the wastewater, oxygen enters the reactor from the bottom and reacts with the epichlorohydrin wastewater. The TOC of the treated epichlorohydrin wastewater is 98.8 ppm, and the TOC removal rate is 99.09%.

[0101] (1) As can be seen from Example 1 and Comparative Examples 1-2, the present invention improves the TOC removal rate of wastewater treatment by introducing a ceramic gas distributor. When the ceramic gas distributor is removed in Comparative Example 1 and replaced with a diffuser aeration disc in Comparative Example 2, the TOC removal rate decreases from 99.95% in Application Example 1 to 98.52% and 99.09%, respectively.

[0102] (2) As can be seen from Application Example 1 and Application Example 12, the present invention can achieve better wastewater treatment effect by optimizing the large aperture of the ceramic gas distributor. When the aperture of the ceramic gas distributor in Application Example 12 is too large, the TOC removal rate decreases.

[0103] In summary, this invention incorporates a ceramic gas distributor into a continuous wet oxidation device, which uniformly distributes micron-sized oxygen bubbles throughout the reactor tubes, thereby improving mass transfer and reaction efficiency.

[0104] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A continuous wet oxidation device for enhanced mass transfer treatment of high-salt organic wastewater, characterized in that, The continuous wet oxidation unit includes a wastewater storage tank, a liquid inlet system, a high-pressure oxygen storage tank, an air inlet system, a mass transfer enhancement reactor, a gas-liquid separation system, and an oxygen recovery system. The mass transfer enhancement reactor is a shell-and-tube structure, including a reactor shell and a built-in ceramic distributor; the ceramic distributor forms a tube side inside, and the ceramic distributor and the reactor shell form a shell side; the tube side is provided with a liquid inlet and a liquid outlet, and the shell side is provided with a gas inlet; The wastewater storage tank is connected to the liquid inlet of the mass transfer enhancement reactor via a liquid inlet system. The high-pressure oxygen storage tank is connected to the gas inlet of the mass transfer enhancement reactor via a gas inlet system. The liquid outlet of the mass transfer enhancement reactor is connected to a gas-liquid separation system. The gas outlet of the gas-liquid separation system is connected to an oxygen recovery system. The oxygen recovery system recovers oxygen to the high-pressure oxygen storage tank.

2. The continuous wet oxidation apparatus according to claim 1, characterized in that, The ceramic distributor is tubular; Preferably, the ceramic distributor includes a dense layer on the inner wall of the ceramic distributor; Preferably, the dense layer is formed by a sol-gel method; Preferably, the pore size of the dense layer is 50nm-2000nm; Preferably, the ceramic distributor is located inside the reactor shell and is arranged along the axial direction of the reactor shell; Preferably, the circumferential outer edges at both ends of the ceramic distributor are sealed and fixed to the reactor shell by high-temperature sealing rings; Preferably, the high-temperature sealing ring is fixed to the stepped surface of the inner wall of the reactor shell by a flange clamping structure; Preferably, both ends of the ceramic distributor are covered with a glaze sealing layer along the end face to the circumferential outer edge that contacts the high-temperature sealing ring; Preferably, the ceramic distributor is made of any one of alumina, zirconium oxide, titanium oxide, and silicon carbide.

3. The continuous wet oxidation apparatus according to claim 1 or 2, characterized in that, The mass transfer enhancement reactor is provided with at least two temperature-controlled heating jackets on the outside of its shell; Preferably, a gas-phase feed inlet is provided on one side of the bottom of the shell of the mass transfer enhancement reactor; Preferably, the mass transfer enhanced reactor has a liquid phase inlet and a liquid phase outlet at both ends of its shell; Preferably, the mass transfer enhancement reactor is a gas-liquid co-current upward reactor.

4. The continuous wet oxidation apparatus according to any one of claims 1-3, characterized in that, The liquid inlet system includes a liquid inlet pipeline; Preferably, a high-pressure metering pump is installed on the liquid inlet pipeline.

5. The continuous wet oxidation apparatus according to any one of claims 1-4, characterized in that, The air intake system includes an air intake pipe; Preferably, a mass flow meter is installed on the air intake pipe; Preferably, a pressure reducing valve is installed on the air inlet pipeline between the high-pressure oxygen storage tank and the mass flow meter.

6. The continuous wet oxidation apparatus according to any one of claims 1-5, characterized in that, The gas-liquid separation system includes a gas-liquid separation tank and a product tank; Preferably, the liquid phase outlet of the gas-liquid separator is connected to the product tank.

7. The continuous wet oxidation apparatus according to any one of claims 1-6, characterized in that, The oxygen recovery system includes an alkali absorption tower, a low-pressure oxygen storage tank, and an oxygen booster. Preferably, the alkali absorption tower is connected to the gas phase outlet of the gas-liquid separation system via a pipeline; Preferably, the low-pressure oxygen storage tank is connected to the alkali absorption tower via a pipeline; Preferably, the oxygen booster pressurizes the gas in the low-pressure oxygen storage tank and then recovers it to the high-pressure oxygen storage tank.

8. A process for treating high-salinity organic wastewater using a continuous wet oxidation device according to any one of claims 1-7, characterized in that, The process includes: High-salt organic wastewater is mixed with a catalyst and added to a wastewater storage tank. The mixture is then pumped to the bottom of the mass transfer enhanced reactor and enters the tube side of the reactor. Simultaneously, high-pressure pure oxygen is transported from a high-pressure oxygen storage tank to the shell side of the mass transfer enhanced reactor. Under the action of pressure difference, the oxygen is rapidly dispersed into micron-sized bubbles by a ceramic distributor and distributed to the tube side of the mass transfer enhanced reactor. The oxygen reacts with the high-salt organic wastewater to undergo an oxidation reaction. The gas-liquid mixture after the reaction is completed is separated by a gas-liquid separation system. The unreacted oxygen is recovered to the high-pressure oxygen storage tank via an oxygen recovery system.

9. The process according to claim 8, characterized in that, The standard gas-liquid volume ratio of oxygen to high-salt organic wastewater is 10-40. Preferably, the catalyst comprises a copper metal salt; Preferably, the copper metal salt includes any one or a combination of at least two of CuSO4, CuCl2 and Cu(NO3)2; Preferably, the catalyst is Cu 2+ The recommended addition amount is 1500-3000 ppm; Preferably, the reaction pressure of the oxidation reaction is 3.0-5.0 MPa; Preferably, the oxidation reaction temperature is 120-240℃; Preferably, the residence time of the high-salt organic wastewater in the mass transfer enhanced reactor is 60-240 min.

10. The process according to claim 8 or 9, characterized in that, The average diameter of the micron-sized bubbles is 100-400 μm.

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