Method for treating organic amine degradation product by catalytic method

Abstract

The invention belongs to the technical field of wastewater treatment, and discloses a method for treating an organic amine degradation product by a catalytic method. Aiming at oxidative degradation and thermal degradation products of an amine absorbent in the decarburization process, coordination chemical bonds are loaded on a composite material to cure transition metal, the composite material is made into a porous polymer, and the porous polymer provides the contact area of the organic amine degradation products and photocatalytic reaction to improve the reaction efficiency. And further oxidizing and degrading COD (Chemical Oxygen Demand) in the organic amine degradation product which is degraded by the photocatalytic oxidation reaction. The cycle index can be determined according to the COD content, the COD removal rate is increased, and the purposes that the COD content of organic amine degradation products cannot be detected, and the organic amine degradation products are completely mineralized can be achieved.

Description

Technical Field

[0001] The invention relates to a method for treating organic amine degradation products by catalysis, belonging to the technical field of wastewater treatment. Background Art

[0002] Abnormal climate change caused by excessive CO2 emissions has become a global environmental problem that troubles human survival and development, and reducing CO2 emissions has become a common issue for countries around the world. The absorption method using amines as absorbents has the advantages of fast gas absorption rate, good removal effect, and good chemical stability, making it the most feasible method for carbon capture.

[0003] Amine absorbents undergo oxidative degradation and thermal degradation during the decarbonization process. The degradation products include formic acid, formamide vinyl alcohol, acetaldehyde, glycine, glycolic acid, hydroxyacetaldehyde, oxazolidinone, oxalamide, N-(2-hydroxyethyl)-acetamide (HEA), dimethylethanolamine (DMEA), etc. The organic amine compounds in the degradation products are difficult to biochemically degrade and have certain toxicity to microorganisms and cannot enter the sewage treatment plant. Traditional wastewater treatment methods include physical, chemical and biological methods.

[0004] The treatment process of industrial wastewater generally adopts a combination of primary physical and chemical treatment (such as filtration, chemical coagulation, and sedimentation) and secondary biological treatment (such as activated sludge method) to treat the wastewater to the discharge standard. However, with the development of industry and the widespread use of special chemicals, the industrial production process produces products, by-products or derivative wastes that are inhibitory or toxic to organisms, or contain high concentrations of difficult-to-degrade organic or inorganic pollutants, making it difficult for traditional sewage treatment equipment to treat.

[0005] Recently, due to the rapid development of the carbon capture industry, the water quality of the wastewater generated has changed greatly, and traditional wastewater treatment processes are simply difficult to treat, so other high-cost treatment processes need to be adopted.

[0006] Photocatalytic oxidation is a new water pollution control technology. It uses semiconductor catalysts (such as TiO2) to generate hydroxyl radicals with strong oxidation ability in water to oxidize pollutants in water, so that they undergo a series of intermediate processes and eventually generate CO2, H2O and other inorganic ions. When semiconductor catalysts are added to sewage, the catalysts are easy to lose and difficult to recover. Ozone direct oxidation treatment technology has a certain effect on the degradation of desulfurization amine-containing wastewater, but the oxidation time is long. Summary of the invention

[0007] The purpose of the present invention is to solve the problems of low treatment efficiency and incomplete mineralization of organic pollutants in existing organic amine degradation product waste liquid, and to propose a method for treating organic amine degradation products by catalysis to achieve harmless treatment technology for organic amine degradation product waste liquid.

[0008] The main technical scheme of the present invention is a method for treating organic amine degradation products by catalytic method, characterized in that a photolysis catalyst supported by a porous composite material is used to decompose the organic amine degradation products, the degradation products after decomposition are catalytically oxidized by ozone to decompose organic pollutants, and COD is removed by continuous cyclic treatment.

[0009] Generally, the method of the present invention includes a photocatalytic reactor and a catalytic oxidation reactor. The organic amine degradation products enter the photocatalytic reactor from the circulation tank and are decomposed under the action of a photocatalytic catalyst. The decomposed degradation products enter the catalytic oxidation reactor and are decomposed by ozone catalytic oxidation. The treatment is cyclically and continuously processed to improve the COD removal rate.

[0010] The photolysis catalyst is iridium salt or niobate salt.

[0011] The porous composite material is a porous polymer of polyethylene or divinylbenzene, and the specific surface area of ​​the porous polymer is 100-600m 2 / m 3 , preferably with a specific surface area of ​​300-550m 2 / m 3 .

[0012] The photocatalytic reactor is provided with photolysis irradiation light, and the wavelength range of the irradiation light is 300-400nm.

[0013] The photolysis irradiation light adopts a mercury lamp with a power of 10-500W, preferably a power of 100-400W.

[0014] The catalytic oxidation reactor is provided with a liquid inlet, an ozone injection port and a waste gas outlet.

[0015] A circulation pump and a flow regulating valve are arranged between the circulation tank, the photocatalytic reactor and the catalytic oxidation reactor.

[0016] The method of the present invention also includes components such as centrifugal pumps and control valves well known in the art.

[0017] The photolysis supported catalyst of the present invention adopts active ligand imidazoline and polyvinyl or divinyl benzene copolymerization to prepare a porous copolymer material containing imidazoline, and then iridium or niobium is coordinated to prepare a supported iridium or niobium complex catalyst.

[0018] The key step in the photocatalytic process is to inhibit the recombination of electrons and holes. O2 adsorbed on the surface of the photocatalyst can prevent the recombination of electrons and holes by capturing electrons to form peroxide ions. Peroxide ions and hydrogen peroxide will produce hydroxyl groups to oxidize and degrade organic amines.

[0019] .

[0020] The photocatalytic redox reaction of the present invention uses transition metal iridium salts and niobates, which have good stability and catalytic activity. Transition metal iridium is expensive. In order to prevent the loss of the catalyst during the use of the transition metal, chemical bonds are used to load the composite material to solidify the transition metal. The composite material is made into a porous polymer. The porous polymer provides a contact area between the organic amine degradation product and the photocatalytic reaction to improve the reaction efficiency.

[0021] The method of the present invention cyclically and continuously degrades COD in the degradation products of organic amines through photocatalysis and catalytic oxidation, and measures the COD content of the products after the reaction. The number of cycles can be determined according to the COD content to improve the COD removal rate, and the purpose of making the COD content of the degradation products of organic amines undetectable and completely mineralized can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the process of the embodiment of the present invention. Implementation

[0023] The content of the method of the present invention is further described below with reference to examples.

[0024] When evaluating the effect of oxidation treatment, COD removal rate is used to express it. The method specified in the national standard GB11914-89 is used to test COD.

[0025] The active ligand imidazoline is copolymerized with polyvinyl or divinylbenzene to prepare a porous copolymer material containing imidazoline. A certain amount of iridium or niobate is added according to the weight of the porous copolymer material to prepare a photocatalyst with different contents. The content of iridium or niobium in the photocatalyst is quantitatively analyzed by a spectrometer, and the specific surface area of ​​the porous copolymer material is measured according to GB / T 19587-2004 "Determination of the specific surface area of ​​solid substances by gas adsorption BET method".

[0026] Example 1: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products were added to the COD treatment device, and the iridium content was 4.9% (wt) using an iridium-based photocatalyst. The surface area was 410 m 2 / m 3 After oxidation degradation in the photocatalytic reactor, the COD is reduced to about 14000 mg / L.

[0027] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 300w Solution circulation volume: 200 L / h.

[0028] Example 2: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products were added to the COD treatment device, and the iridium content was determined to be 5.1% (wt) using a niobium-based photocatalyst. The surface area was determined to be 423 m 2 / m 3 After oxidation degradation in the photocatalytic reactor, COD is reduced to about 16000 mg / L.

[0029] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 300w Solution circulation volume: 200 L / h.

[0030] Example 3: A high concentration of COD organic amine degradation products in a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 4000 mg / L through oxidative degradation in the iridium-based photocatalytic reactor and the catalytic oxidation reactor.

[0031] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 300w Ozone concentration: 25mg / L Ozone intake volume: 1.5 L / min Solution circulation volume: 200 L / h.

[0032] Example 4: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 3000 mg / L through oxidative degradation in the iridium-based photocatalytic reactor and the catalytic oxidation reactor.

[0033] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 350w Ozone concentration: 30mg / L Ozone intake volume: 2.0 L / min Solution circulation volume: 200 L / h.

[0034] Example 5: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 2000 mg / L through oxidation degradation in the niobium-based photocatalytic reactor and the catalytic oxidation reactor.

[0035] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Ozone concentration: 30mg / L Ozone intake: 2.5 L / min Solution circulation volume: 180 L / h.

[0036] Example 6: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 17000 mg / L through oxidation degradation in the iridium-based photocatalytic reactor.

[0037] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Polymer surface area: 306m 2 / m 3 Solution circulation volume: 220 L / h.

[0038] Example 7: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 12000 mg / L through oxidation degradation in the iridium-based photocatalytic reactor.

[0039] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Polymer surface area: 601m 2 / m 3 Solution circulation volume: 220 L / h.

[0040] Example 8: A high concentration of COD organic amine degradation products of a factory, the COD concentration of organic amine degradation products is about 58000mg / L. 3 The organic amine degradation products are added to the COD treatment device, and the COD is reduced to about 600 mg / L through oxidative degradation in the iridium-based photocatalytic reactor and the catalytic oxidation reactor.

[0041] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Ozone concentration: 30mg / L Ozone intake: 2.5 L / min Solution circulation volume: 150 L / h.

[0042] Example 9: The reaction product of Example 8 is used for secondary circulation, and the reaction product is passed through an iridium-based photocatalytic reactor and a catalytic oxidation reactor. The reactor oxidatively degrades COD to about 3 mg / L.

[0043] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Ozone concentration: 30mg / L Ozone intake: 2.5 L / min Solution circulation volume: 200 L / h.

[0044] Example 10: The reaction product of Example 9 was used for three cycles, and the COD was not detected after oxidation degradation in an iridium-based photocatalytic reactor and a catalytic oxidation reactor.

[0045] (2) Test conditions Reaction temperature: ~40 o C Photolysis irradiation light power: 500w Ozone concentration: 30mg / L Ozone intake: 0.5 L / min Solution circulation volume: 600 L / h.

Claims

1. A method for treating organic amine degradation products by catalysis, characterized in that: The photocatalytic decomposition catalyst supported by porous composite materials is used to decompose the degradation products of organic amines. The degradation products after decomposition are catalytically oxidized by ozone to decompose organic pollutants, and COD is removed by continuous cyclic treatment.

2. The method according to claim 1, characterized in that It includes a circulation tank, a photocatalytic reactor and a catalytic oxidation reactor. The organic amine degradation products enter the photocatalytic reactor from the circulation tank and are decomposed under the action of a photocatalyst. The decomposed degradation products enter the catalytic oxidation reactor and are decomposed by ozone catalytic oxidation. The treatment is cyclically and continuously processed to improve the COD removal rate.

3. The method according to claim 1, characterized in that The photolysis catalyst is iridium salt or niobate salt.

4. The method according to claim 1, characterized in that The porous composite material is a porous polymer of polyethylene or divinylbenzene, and the specific surface area of ​​the porous polymer is 100-600m 2 / m 3 .

5. The method according to claim 4, characterized in that The porous polymer has a specific surface area of ​​300-550 m 2 / m 3 .

6. The method according to claim 2, characterized in that The photocatalytic reactor is provided with photolysis irradiation light, and the wavelength range of the irradiation light is 300-400nm.

7. The method according to claim 6, characterized in that The photolysis irradiation light adopts a mercury lamp with a power of 10-500W.

8. The method according to claim 7, characterized in that The power is 100-400W.

9. The method according to claim 2, characterized in that The catalytic oxidation reactor is provided with a liquid inlet, an ozone injection port and a waste gas outlet.

10. The method according to claim 2, characterized in that A circulation pump and a flow regulating valve are arranged between the circulation tank, the photocatalytic reactor and the catalytic oxidation reactor.

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