Polycarbonate salt water deep treatment and resource utilization method

Abstract

This invention provides a method for the deep treatment and resource utilization of polycarbonate brine. The method includes the following steps: preparing a modified support for PO / SM tar-coal slag; preparing a cobalt and / or cerium phosphate ester complex metal; dissolving the phosphate ester complex metal to obtain a solution; impregnating the modified support; drying; and calcining to obtain a catalytic oxidation catalyst. The catalyst comprises a support and an active component; the support is a modified support for the co-production of styrene (PO / SM) tar from propylene oxide, and the active component is the phosphate ester complex metal. The catalyst of this invention can effectively remove organic matter, reduce ion-exchange membrane voltage, and realize the resource utilization of waste brine.

Description

TECHNICAL FIELD

[0001] The application relates to a polycarbonate salt water deep treatment and resource utilization method and belongs to the technical field of environmental protection wastewater treatment. BACKGROUND

[0002] Polycarbonate, also known as PC plastic, is a high molecular polymer containing carbonate groups in the molecular chain, is an engineering plastic with excellent comprehensive performance, and has become the fastest-growing general-purpose engineering plastic among the five engineering plastics. Due to its good mechanical properties, heat aging resistance, solvent resistance, water stability, insulation and molding processing type and other advantages, the PC is widely applied in the fields of building materials, automobile manufacturing, medical treatment, aerospace, packaging and optics. The synthesis process of PC mainly includes the light gas and ester exchange methods. In the light gas synthesis process, a large amount of high-salt wastewater is generated, which generally needs to be deep treated and discharged into the sea or evaporated and crystallized.

[0003] At present, the polycarbonate wastewater in the industry is usually treated by advanced oxidation or adsorption method. For example, CN105233828A adopts catalytic oxidation to rapidly degrade bisphenol A, and CN103739136A adopts stripping + acid precipitation + activated carbon adsorption process. At present, the PC salt water in the device has been treated by stripping + acid precipitation + resin + activated carbon and discharged into the sea. The above processes only treat the organic matters in the wastewater, and do not further reuse the large amount of inorganic salt in the wastewater, so that the overall economic benefit is not high.

[0004] Therefore, in the field of salt-containing wastewater, a further deep treatment process is developed, an efficient deep treatment process is developed, the substances affecting the membrane voltage in the waste salt water are reduced, and the waste salt water reaches or is better than the salt water prepared from the original salt in terms of alkali production efficiency and energy consumption.

[0005] Based on the above background, a new polycarbonate wastewater deep treatment technology is needed to be developed to realize resource utilization of waste salt water. SUMMARY

[0006] The application aims to provide a new polycarbonate wastewater deep treatment technology and resource utilization method. The catalyst of the application can effectively decompose the organic matters in the wastewater, and the treatment method is simple and easy to operate, has high treatment efficiency, does not cause metal loss, and can effectively reduce the ion membrane voltage and energy consumption.

[0007] To solve the above technical problems, the technical scheme adopted by the application is as follows:

[0008] A catalyst for a catalytic oxidation reaction, the catalyst comprising a support and an active component, the support being a modified support for the co-production of styrene (PO / SM) tar from propylene oxide, and the active component being a phosphate ester complexed with a metal, preferably one or more of a phosphate ester complexed with cobalt chloride, a phosphate ester complexed with cerium chloride, and a phosphate ester complexed with a bimetallic cobalt chloride / cerium chloride; the active component is 1.0-10.0 wt%, preferably 5.0-10.0 wt%, based on the weight of the support.

[0009] In this invention, PO / SM tar and activated carbon are used to modify the carrier, giving it a resource-recycling capacity with a large specific surface area, strong adsorption performance, and high loading capacity, resulting in high contact efficiency with the oxidant persulfate and organic matter. By loading phosphate ester-complexed cobalt chloride, phosphate ester-complexed cerium chloride, and phosphate ester-complexed bimetallic cobalt chloride + cerium chloride, the oxidant is activated by the catalyst in the free radical pathway, generating reactive oxygen species such as sulfate radicals, oxygen radicals, and hydroxyl radicals, which can further improve the peroxidation efficiency. These free radicals can react with organic pollutants, thereby achieving pollutant degradation.

[0010] Another object of the present invention is to provide a method for preparing a catalyst for catalytic oxidation reactions.

[0011] A method for preparing a catalyst for the above-mentioned catalytic oxidation reaction, the method comprising the following steps:

[0012] S1: Preparation of modified carriers for PO / SM tar-coal slag;

[0013] S2: Preparation of cobalt and / or cerium phosphate ester complex metals;

[0014] S3: Dissolve the phosphate ester complex metal to obtain a solution, and then impregnate the modified carrier;

[0015] S4: Dry and calcine to obtain a catalytic oxidation catalyst.

[0016] In one embodiment of the present invention, in step S1, PO / SM tar is mixed with waste powdered activated carbon precipitate to obtain modified PO / SM tar particles; preferably, the PO / SM tar is taken from styrene tar from a PO / SM unit, and its main components are styrene and polycyclic polymers; preferably, the waste powdered activated carbon precipitate is taken from a hydrometallurgical wastewater treatment unit, preferably with an average particle size of 10-50 μm and a moisture content of 40-70 wt%; preferably, the mass ratio of PO / SM tar to waste powdered activated carbon precipitate is 1:(1-10); preferably, in step S1, excess sulfuric acid is used to treat PO / SM tar and waste powdered activated carbon precipitate; preferably, a mass ratio of (2-10):1 is used for treatment.

[0017] In one embodiment, 2-10 times the mass of sulfuric acid as a carrier is added, and the mixture is sonicated for 60-120 min. Then, it is heated to 40-80°C and stirred for 2-8 h. The mixture is washed 3-5 times with deionized water, and after precipitation, the slurry is granulated and placed in a constant-temperature drying oven at 105°C for 2-3 h to obtain dry granular material. This material is placed in a reaction tube, and helium gas is introduced at 5-20 mL / min. The reaction temperature is controlled at 120-280°C, preferably 150-200°C, for 5-12 h, more preferably 6-8 h. After cooling to room temperature, the mixture is washed 3-5 times with water, then washed 3-5 times with anhydrous ethanol, and dried in a constant-temperature drying oven at 90-105°C for 2-3 h to obtain the modified carrier.

[0018] This invention utilizes sulfuric acid to modify PO / SM tar and waste powdered activated carbon. Styrene and polycyclic polymers can undergo sulfonation reactions under 98% sulfuric acid, 160°C, and normal pressure conditions, for example, to form naphthalene sulfonic acid polymers. The modification of powdered activated carbon under sulfuric acid conditions increases the pore area. The naphthalene sulfonic acid polymer and powdered activated carbon achieve improved stability through electrostatic repulsion, forming a high-strength, multi-porous carrier material under high-temperature, oxygen-containing conditions.

[0019] In one embodiment of the present invention, the method for preparing the phosphate ester complex metal in step S2 is as follows:

[0020] S2-1: React phosphate esters with alkali metal hydroxides to obtain alkali metal soap phosphate ester solutions;

[0021] S2-2: Cobalt and / or cerium chlorides are mixed with an alkali metal soap phosphate solution, the pH is adjusted, and the mixture is dried after the reaction to obtain a phosphate ester complex metal.

[0022] In one embodiment of the present invention, in S2-1, the phosphate ester is prepared using C10-C20 phosphoric acid, preferably one or more of di-(2-ethylhexyl)phosphoric acid, 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester, and di(2,4,4-trimethyl)pentylphosphoric acid, more preferably di-(2-ethylhexyl)phosphoric acid.

[0023] In one embodiment of the present invention, the molar ratio of phosphate ester to alkali metal hydroxide in S2-1 is 1:(0.9-1.1).

[0024] In one embodiment of the present invention, the phosphate ester in S2-1 reacts with the alkali metal hydroxide for 1-5 hours.

[0025] In one embodiment of the present invention, the molar ratio of chloride to alkali metal saponified phosphate in S2-2 is 5:(1-5).

[0026] In one embodiment of the present invention, the pH in S2-2 is adjusted to 2-3.

[0027] In one embodiment of the present invention, the reaction temperature in S2-2 is 40-80°C, preferably 50-60°C, and the reaction time is 1-5h, preferably 2-4h.

[0028] In one embodiment of the present invention, the mass ratio of the phosphate ester complex metal to the modified support in S3 is 1:(10-100).

[0029] Another object of the present invention is to provide a use for a catalyst.

[0030] The use of a catalyst, which is the catalyst described above or prepared by the method described above, for catalytic oxidation reactions, preferably for the deep treatment and resource utilization of polycarbonate brine.

[0031] Another object of the present invention is to provide a method for the deep treatment and resource utilization of polycarbonate brine.

[0032] A method for deep treatment and resource utilization of polycarbonate brine, the method employing the catalyst described above, or a catalyst prepared using the method described above, the method comprising the following steps:

[0033] SS1: Concentrate polycarbonate brine to obtain concentrated brine;

[0034] SS2: Membrane filtration concentrates brine to remove impurities, yielding purified brine;

[0035] SS3: After adjusting the pH of the purified brine, an oxidant is added and it comes into contact with the catalyst to carry out a catalytic oxidation reaction, thus obtaining a deeply treated brine.

[0036] SS4: The deeply treated brine is electrolyzed through an ion-exchange membrane to obtain a sodium hydroxide solution.

[0037] In one embodiment of the invention, SS1 is concentrated to 20-25 wt%.

[0038] In one embodiment of the present invention, the pH of SS3 is adjusted to 5-7.

[0039] In one embodiment of the present invention, the reaction temperature in SS3 is 55-85°C and the reaction time is 0.5-4h.

[0040] In one embodiment of the present invention, the mass ratio of the added oxidant in SS3 is oxidant:TOC = (0.1-10):1.

[0041] Unless otherwise specified in the instruction manual, all percentages are in wt%.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) Through the process and catalyst of this invention, the organic matter in wastewater can be treated to TOC < 5ppm through concentration + filtration + catalytic oxidation, which not only meets the discharge standard for the sea, but also meets the standard for use of ion membranes.

[0044] (2) Using the brine treated by the present invention for ion membrane electrolysis, a 32% sodium hydroxide solution is obtained, with a power consumption of 1980 kw·h per ton of alkali, which is comparable to the power consumption of the original salt.

[0045] (3) Caustic soda is produced from waste brine, realizing resource recovery and recycling, and reducing the exploitation and consumption of natural resources. This method not only reduces waste discharge, but also reduces environmental pollution. Detailed Implementation

[0046] The following specific embodiments further illustrate the technical solution and effects of the present invention. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0047] Main equipment models and raw material sources in the embodiments of the present invention

[0048] Wastewater storage tanks, catalytic oxidizers, wastewater lift pumps, wastewater transfer pumps, and static mixers were purchased from Yantai Keli Chemical Equipment Co., Ltd.

[0049] The muffle furnace, model VULCAN 3-1750, was purchased from Neytech, USA.

[0050] PC brine, from Wanhua Chemical's PC unit, contains 8% sodium chloride and 15ppm TOC;

[0051] PO / SM tar, from Wanhua Chemical's PO / SM unit;

[0052] Waste activated carbon, Wanhua Chemical wastewater treatment equipment;

[0053] Cerium chloride, cobalt chloride, sodium persulfate, and phosphate esters were all of analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd.

[0054] Hydrochloric acid solution, Wanhua Chemical, concentration 30wt%;

[0055] The ion exchange membrane used is model DF2807, which comes from Dongyue Group; the pilot-scale ion exchange membrane electrolysis equipment was ordered from Hangzhou Lanran Technology Co., Ltd.

[0056] Preparation Example 1

[0057] The preparation method of phosphate ester complexed cobalt chloride is as follows: 100g of di-(2-ethylhexyl)phosphoric acid is mixed with 30% sodium hydroxide at a mass ratio of 2.42:1 (molar ratio 1:1), stirred for 2 hours, and then allowed to stand for 30 minutes to form a sodium soap phosphate ester solution. A cobalt chloride solution with a cobalt content of 10% is then added and mixed with the sodium soap phosphate ester solution at a mass ratio of 4.38:1 (molar ratio 5:2). The pH is adjusted to 2 with 98% sulfuric acid, and the mixture is heated and stirred under nitrogen protection at 40℃ for 2 hours. The resulting oil phase is then vacuum dried at 150℃ for 5 hours to obtain the phosphate ester complexed cobalt chloride. Inductively coupled plasma mass spectrometry (Agilent 7900 ICP-MS) was used to analyze the metal ion content in the obtained phosphate ester solution, showing a cobalt content of 31.4 wt%, indicating good complexing effect. A 20 wt% concentration sample was prepared using kerosene.

[0058] Preparation Example 2

[0059] The preparation method of phosphate ester-complexed cerium chloride is as follows: 100g of di-(2-ethylhexyl)phosphoric acid is mixed with 30% sodium hydroxide at a mass ratio of 2.69:1 (molar ratio 1:0.9), stirred for 5 hours, and then allowed to stand for 30 minutes to form a sodium soap phosphate ester solution. A cerium chloride solution with a cerium content of 10% is then added and mixed with the sodium soap phosphate ester solution at a mass ratio of 4.35:1 (molar ratio 5:2). The pH is adjusted to 3 with 98% sulfuric acid, and the mixture is heated and stirred under nitrogen protection at 50℃ for 5 hours. The resulting oil phase is then vacuum dried at 150℃ for 5 hours to obtain the phosphate ester-complexed cerium chloride. Inductively coupled plasma mass spectrometry (Agilent 7900 ICP-MS) was used to analyze the metal ion content in the obtained phosphate ester solution. The cerium content reached 30.3 wt%, indicating good complexation effect. A 20 wt% concentration sample was prepared using kerosene.

[0060] Preparation Example 3

[0061] The preparation method of phosphate ester complexed cobalt chloride is as follows: 100g of 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester is mixed with 30% sodium hydroxide at a mass ratio of 2.20:1 (molar ratio 1:1), stirred for 5h, and then allowed to stand for 30min to form a sodium soap phosphate ester solution; then a cobalt chloride solution with a cobalt content of 10% is added and mixed with the sodium soap phosphate ester solution at a mass ratio of 9.64:1 (molar ratio 5:1), and the pH is adjusted to 3 with 98% sulfuric acid. The mixture is heated and stirred under nitrogen protection at 60℃ for 1h; the resulting oil phase is then vacuum dried at 150℃ for 5h to obtain phosphate ester complexed cobalt chloride. The metal ion content in the obtained phosphate ester solution was analyzed using inductively coupled plasma mass spectrometry (Agilent 7900ICP-MS), and the cobalt content reached 49.1wt%, indicating good complexing effect. A 20wt% concentration sample was prepared using kerosene.

[0062] Preparation Example 4

[0063] The preparation method of phosphate ester-complexed cerium chloride is as follows: 100g of 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester is mixed with 30% sodium hydroxide at a mass ratio of 2.42:1 (molar ratio 1:1), stirred for 1 hour, and then allowed to stand for 30 minutes to form a sodium soap phosphate ester solution. A cerium chloride solution with a cerium content of 10% is then added and mixed with the sodium soap phosphate ester solution at a mass ratio of 5.09:1 (molar ratio 5:2). The pH is adjusted to 2 with 98% sulfuric acid, and the mixture is heated and stirred under nitrogen protection at 80℃ for 2 hours. The resulting oil phase is then vacuum dried at 150℃ for 5 hours to obtain the phosphate ester-complexed cerium chloride. Inductively coupled plasma mass spectrometry (Agilent 7900ICP-MS) was used to analyze the metal ion content in the obtained phosphate ester solution. The cerium content reached 31.4wt%, indicating good complexation effect. A 20wt% concentration sample was prepared using kerosene.

[0064] Preparation Example 5

[0065] The preparation method of phosphate ester-complexed cobalt chloride is as follows: 100g of di(2,4,4-trimethyl)pentylphosphic acid is mixed with 30% sodium hydroxide at a mass ratio of 2.69:1 (molar ratio 1:0.9), stirred for 2 hours, and then allowed to stand for 30 minutes to form a sodium soap phosphate ester solution. A 10% cobalt chloride solution is then added and mixed with the sodium soap phosphate ester solution at a mass ratio of 4.38:1 (molar ratio 5:2). The pH is adjusted to 2 with 98% sulfuric acid, and the mixture is heated and stirred under nitrogen protection at 60℃ for 4 hours. The resulting oil phase is then vacuum dried at 150℃ for 5 hours to obtain the phosphate ester-complexed cobalt chloride. Inductively coupled plasma mass spectrometry (Agilent 7900 ICP-MS) was used to analyze the metal ion content in the obtained phosphate ester solution, showing a cobalt content of 33.7 wt%, indicating good complexation effect. A 20 wt% concentration sample was prepared using kerosene.

[0066] Preparation Example 6

[0067] The preparation method of phosphate ester-complexed cerium chloride is as follows: 100g of di(2,4,4-trimethyl)pentylphosphic acid is mixed with 30% sodium hydroxide at a mass ratio of 2.42:1 (molar ratio 1:1), stirred for 5 hours, and then allowed to stand for 30 minutes to form a sodium soap phosphate ester solution. A cerium chloride solution with a cerium content of 10% is then added and mixed with the sodium soap phosphate ester solution at a mass ratio of 12.07:1 (molar ratio 5:2). The pH is adjusted to 2 with 98% sulfuric acid, and the mixture is heated and stirred under nitrogen protection at 60℃ for 4 hours. The resulting oil phase is then vacuum dried at 150℃ for 5 hours to obtain the phosphate ester-complexed cerium chloride. Inductively coupled plasma mass spectrometry (Agilent 7900 ICP-MS) was used to analyze the metal ion content in the obtained phosphate ester solution, showing a cerium content of 54.6 wt%, indicating good complexation effect. A 20 wt% concentration sample was prepared using kerosene.

[0068] Example 1

[0069] Take 20g of PO / SM tar and 20g of waste powdered activated carbon (particle size 10μm, moisture content 40wt%) precipitate (dry basis), add 80mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 6h, cool to room temperature, and obtain the modified support.

[0070] Take 1 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 1) and 1 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 2) and dissolve them in 30% ethanol to prepare 20 mL of impregnation solution. Add 20 g of support under a nitrogen atmosphere for impregnation for 60 min and calcine at 300 °C for 3 h to obtain catalyst #1.

[0071] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 140 mg / L. Catalytic oxidation was carried out in contact with catalyst #1. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 11 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2356kwh / tNaOH.

[0072] Example 2

[0073] Take 4g of PO / SM tar and 20g of waste powdered activated carbon (40μm particle size, 40wt% moisture content) precipitate (dry basis), add 120mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 3h, cool to room temperature, and obtain the modified support.

[0074] Take 1 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 3) and 1 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 4) and dissolve them in 30% ethanol to prepare 20 mL of impregnation solution. Add 20 g of support under a nitrogen atmosphere for impregnation for 60 min and calcine at 300 °C for 2 h to obtain catalyst #2.

[0075] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 55°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 28 mg / L, and the reaction proceeded in contact with catalyst #2. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 0.5 h, yielding a deeply treated brine with a TOC of 15 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2856kwh / tNaOH.

[0076] Example 3

[0077] Take 4g of PO / SM tar and 20g of waste powdered activated carbon (50μm particle size, 40wt% moisture content) precipitate (dry basis), add 240mL of 98% sulfuric acid, heat to 60℃ and sonicate for 100min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 350℃, react for 6h, cool to room temperature, and obtain the modified support.

[0078] Take 1 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 1) and dissolve it in 30% ethanol to prepare 20 mL of impregnation solution. Add 20 g of support under a nitrogen atmosphere for impregnation for 60 min. Then calcine at 300 °C for 3 h to obtain catalyst #3.

[0079] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 85°C, it entered a catalytic oxidation reactor. Sodium persulfate was added to achieve a concentration of 280 mg / L, and catalytic oxidation was carried out in contact with catalyst #3. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 1 hour, yielding a deeply treated brine with a TOC of 12 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2410kwh / tNaOH.

[0080] Example 4

[0081] Take 2g of PO / SM tar and 20g of waste powdered activated carbon (40μm particle size, 70wt% moisture content) precipitate (dry basis), add 44mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 6h, cool to room temperature, and obtain the modified support.

[0082] Take 5 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 5) and 5 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 6) and dissolve them in 30% ethanol to prepare 20 mL of impregnation solution. Add 20 g of support under a nitrogen atmosphere for impregnation for 60 min and calcine at 300 °C for 3 h to obtain catalyst #4.

[0083] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 5 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 60°C, it entered a catalytic oxidation reactor. Hydrogen peroxide was added to achieve a concentration of 140 mg / L, and catalytic oxidation was carried out in contact with catalyst #4. The hydrogen peroxide rapidly converted to hydroxyl radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 13 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2287kwh / tNaOH.

[0084] Example 5

[0085] Take 2g of PO / SM tar and 20g of waste powdered activated carbon (40μm particle size, 70wt% moisture content) precipitate (dry basis), add 110mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 6h, cool to room temperature, and obtain the modified support.

[0086] Take 5 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 1) and 5 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 2) and dissolve them in 30% ethanol to prepare 20 mL of impregnation solution. Add 20 g of support under a nitrogen atmosphere for impregnation for 60 min and calcine at 300 °C for 3 h to obtain catalyst #5.

[0087] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 5 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 2.8 mg / L. Catalytic oxidation was carried out in contact with catalyst #5. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 4 hours, yielding a deeply treated brine with a TOC of 17 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2899kwh / tNaOH.

[0088] Example 6

[0089] Take 4g of PO / SM tar and 20g of waste powdered activated carbon (50μm particle size, 50wt% moisture content) precipitate (dry basis), add 240mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 6h, cool to room temperature, and obtain the modified support.

[0090] 10 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 1) and 10 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 2) were dissolved in 30% ethanol to prepare 24 mL of impregnation solution. 24 g of support was added under a nitrogen atmosphere for impregnation for 60 min. The solution was then calcined at 300 °C for 3 h to obtain catalyst #6.

[0091] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 5 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added to achieve a concentration of 140 mg / L, and the reaction proceeded in contact with catalyst #6. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 5 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2029kwh / tNaOH.

[0092] Example 7

[0093] Take 2g of PO / SM tar and 20g of waste powdered activated carbon (50μm particle size, 50wt% moisture content) precipitate (dry basis), add 220mL of 98% sulfuric acid, heat to 80℃ and sonicate for 120min, rinse 5 times with deionized water, take the slurry and granulate it, place it in a constant temperature drying oven and dry at 105℃ for 2h to obtain dry granular material. Place the granules in a titanium alloy oxidation reaction tube, introduce helium gas at 20mL / min, control the sintering reaction temperature at 280℃, react for 6h, cool to room temperature, and obtain the modified support.

[0094] Take 10 mL of 0.2 g / mL phosphate ester complexed cobalt chloride (Preparation Example 1) and 10 mL of 0.2 g / mL phosphate ester complexed cerium chloride (Preparation Example 2) and dissolve them in 30% ethanol to prepare 24 mL of impregnation solution. Add 24 g of support under a nitrogen atmosphere for impregnation for 60 min. Calcine at 300 °C for 3 h to obtain catalyst #7.

[0095] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 140 mg / L. Catalytic oxidation was carried out in contact with catalyst #3. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 3 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 1980kwh / tNaOH.

[0096] Comparative Example 1

[0097] Compared with Example 1, the only difference is that tartaric acid was used as the complexing agent, while the other conditions were the same as in Example 1, resulting in Comparative Example 1# catalyst.

[0098] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added to achieve a concentration of 140 mg / L, and the reaction proceeded in contact with catalyst #1. The peroxy group of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 20 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2684kwh / tNaOH.

[0099] Comparative Example 2

[0100] Compared with Example 1, the only difference is that coconut shell activated carbon is used as the carrier, while other conditions are the same as in Example 1, resulting in Comparative Example 2 catalyst.

[0101] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 140 mg / L. Catalytic oxidation was carried out in contact with catalyst #2 (comparative example). The peroxy groups of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 21 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2725kwh / tNaOH.

[0102] Comparative Example 3

[0103] Compared with Example 1, the only difference is that copper chloride is used as the active metal, while other conditions are the same as in Example 1, resulting in Comparative Example 3 catalyst.

[0104] PC waste brine was concentrated to 25% using MVR evaporation. The concentrated brine was then filtered through an NF membrane at room temperature and 30 bar to remove impurities such as PC oligomers, silicates, and BPA. The filtered brine, with a TOC of 28 mg / L, was adjusted to pH 7 using sulfuric acid via a pipeline mixer. After passing through a heat exchanger and steam heater to 80°C, it entered a catalytic oxidation reactor. Sodium persulfate was added as an oxidant to achieve a concentration of 140 mg / L. Catalytic oxidation was carried out in contact with catalyst #3 (comparative example). The peroxy groups of sodium persulfate rapidly converted into two free radicals, breaking down the organic compounds. The reaction time was 2 hours, yielding a deeply treated brine with a TOC of 24 ppm. This deeply treated brine was then subjected to ion-exchange membrane electrolysis at a current density of 5.5 kA / m³. 2 The electrolytic cell temperature was 85℃, the feed brine concentration was 300g / L, the cell voltage was 3.45V, the catholyte discharge sodium hydroxide concentration was 32%, and the power consumption was 2738kwh / tNaOH.

[0105] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A catalyst for catalytic oxidation reactions, characterized in that, The catalyst comprises a support and an active component. The support is a modified support for styrene (PO / SM) tar produced from propylene oxide. The active component is a phosphate ester complexed with a metal, preferably one or more of the following: phosphate ester complexed with cobalt chloride, phosphate ester complexed with cerium chloride, and phosphate ester complexed with bimetallic cobalt chloride / cerium chloride. The active component is 1.0-10.0 wt%, preferably 5.0-10.0 wt%, based on the weight of the carrier.

2. A method for preparing the catalyst for the catalytic oxidation reaction according to claim 1, characterized in that, The method includes the following steps: S1: Preparation of modified carriers for PO / SM tar-coal slag; S2: Preparation of cobalt and / or cerium phosphate ester complex metals; S3: Dissolve the phosphate ester complex metal to obtain a solution, and then impregnate the modified carrier; S4: Dry and calcine to obtain a catalytic oxidation catalyst.

3. The method according to claim 2, characterized in that, In S1, PO / SM tar is mixed with waste powdered activated carbon precipitate to obtain modified PO / SM tar particles; Preferably, the PO / SM tar is taken from the styrene tar of the PO / SM unit, and its main components are styrene and polycyclic polymers; Preferably, the waste powdered activated carbon precipitate is taken from a hydrometallurgical wastewater treatment device, and preferably has an average particle size of 10-50 μm and a moisture content of 40-70 wt%. Preferably, the mass ratio of PO / SM tar to waste powdered activated carbon precipitate is 1:(1-10); Preferably, in step S1, excess sulfuric acid is used to treat the PO / SM tar and waste powdered activated carbon precipitate; more preferably, a mass ratio of (2-10):1 is used for treatment.

4. The method according to claim 2, characterized in that, The preparation method of the phosphate ester complex metal in S2 is as follows: S2-1: React phosphate esters with alkali metal hydroxides to obtain alkali metal soap phosphate ester solutions; S2-2: Cobalt and / or cerium chlorides are mixed with an alkali metal saponified phosphate ester solution, the pH is adjusted, and the mixture is dried after the reaction to obtain a phosphate ester complex metal.

5. The method according to claim 4, characterized in that, In S2-1, the phosphate ester is prepared using C10-C20 phosphoric acid, preferably one or more of di-(2-ethylhexyl)phosphoric acid, 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester, and di(2,4,4-trimethyl)pentylphosphoric acid, more preferably di-(2-ethylhexyl)phosphoric acid; And / or, in S2-1, the molar ratio of phosphate ester to alkali metal hydroxide is 1:(0.9-1.1); And / or, in S2-1, phosphate esters react with alkali metal hydroxides for 1-5 hours.

6. The phosphate ester according to claim 5, characterized in that, The molar ratio of chloride to alkali metal saponified phosphate in S2-2 is 5:(1-5); And / or, adjust the pH in S2-2 to 2-3; And / or, the reaction temperature in S2-2 is 40-80℃, preferably 50-60℃, and the reaction time is 1-5h, preferably 2-4h.

7. The method according to claim 2, characterized in that, The mass ratio of phosphate ester complex metal to modified support in S3 is 1:(10-100).

8. Use of a catalyst, wherein the catalyst is the catalyst of claim 1, or a catalyst prepared by the method of any one of claims 2-7, the catalyst being used for catalytic oxidation reactions, preferably for the deep treatment and resource utilization of polycarbonate brine.

9. A method for deep treatment and resource utilization of polycarbonate brine, wherein the method uses the catalyst described in claim 1, or the catalyst prepared by any one of claims 2-7, characterized in that, The method includes the following steps: SS1: Concentrate polycarbonate brine to obtain concentrated brine; SS2: Membrane filtration concentrates brine to remove impurities, yielding purified brine; SS3: After adjusting the pH of the purified brine, an oxidant is added and it comes into contact with the catalyst to carry out a catalytic oxidation reaction, thus obtaining a deeply treated brine. SS4: The deeply treated brine is electrolyzed through an ion-exchange membrane to obtain a sodium hydroxide solution.

10. The method according to claim 9, characterized in that, Concentrate to 20-25 wt% in SS1; And / or, adjust the pH of SS3 to 5-7; And / or, the reaction temperature in SS3 is 55-85℃, and the reaction time is 0.5-4h; And / or, the mass ratio of the added oxidant in SS3 is oxidant:TOC = (0.1-10):1.