CN111808038A - Method for recovering cyanuric acid by catalytic degradation of melamine resin - Google Patents
Method for recovering cyanuric acid by catalytic degradation of melamine resin Download PDFInfo
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- CN111808038A CN111808038A CN202010682948.5A CN202010682948A CN111808038A CN 111808038 A CN111808038 A CN 111808038A CN 202010682948 A CN202010682948 A CN 202010682948A CN 111808038 A CN111808038 A CN 111808038A
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- melamine resin
- cyanuric acid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/30—Only oxygen atoms
- C07D251/32—Cyanuric acid; Isocyanuric acid
Abstract
The invention belongs to the field of cyclic utilization and resource utilization of resin solid wastes, and particularly relates to a method for recovering cyanuric acid by catalytic degradation of melamine resin. The method comprises the following steps: crushing melamine resin materials into granules, immersing the granules into a catalyst-solvent liquid phase reaction system, reacting at 120-300 ℃, cooling to room temperature after the reaction is finished, and separating and recycling to obtain cyanuric acid.
Description
Technical Field
The invention belongs to the field of cyclic utilization and resource utilization of resin solid wastes, and particularly relates to a method for recovering cyanuric acid by catalytic degradation of melamine resin.
Background
Melamine resin is also called melamine formaldehyde resin, cyanuric acid formaldehyde resin (MF), which is a polymer obtained by reacting cyanuric acid with formaldehyde. The product is used as a starting point, different process conditions are adopted according to different purposes, a series of products with different purposes are derived, a cross-linking reaction occurs during processing and molding, and the product is infusible thermosetting resin. Melamine resin is widely applied to a plurality of fields such as catering and children toys, and the like, and the yield of the melamine resin is about millions of tons every year in China. Because melamine resin products have high chemical stability and are not easily catalyzed and degraded by light, microorganisms, water and the like in the environment, a large amount of waste can be accumulated in living space of people, and not only occupies space, but also causes hidden troubles of soil pollution or underground water pollution.
The existing method for recovering and treating waste melamine resin mainly comprises a mechanical treatment method and a high-temperature pyrolysis method. The mechanical treatment method is to mechanically crush cured and molded melamine resin, to be used as a filler to be added into a new round of synthesis of thermosetting resin, and to regulate and control the size and filling amount of the mechanical crushing of the melamine resin according to the performance requirement of the synthetic resin. The method usually needs higher energy consumption, and the crushed melamine granules have small bonding force with new resin, so that the mechanical property of new melamine products can be obviously influenced, the additional value is low, and the economical efficiency is poor. The high-temperature pyrolysis method is mainly used for carrying out high-temperature treatment on waste melamine resin, and chemical bonds in the resin are opened in a non-selective manner by utilizing high temperature, so that corresponding components are recovered.
Cyanuric acid (Cyanuric acid, chemical formula: C3H3N3O3), the chinese alias: isocyanuric acid, cyanuric acid, 1, 3, 5-triazine-2, 4, 6- (1H, 3H, 5H) trione and the like are triazine organic compounds and are used for detecting manganese and serving as chemical raw materials. The compound is mainly used as an organic synthesis raw material for synthesizing chloro derivatives, namely trichloroisocyanuric acid; sodium or potassium dichloroisocyanurate; used for synthesizing cyanuric acid-formaldehyde resin; an epoxy resin; an antioxidant; coating; a binder; a pesticide herbicide; a metal cyanidation corrosion inhibitor; polymer material modifiers, and the like. If ether bonds and C-NH2 bonds in melamine resin can be selectively opened under appropriate reaction conditions, melamine is catalytically degraded into cyanuric acid, which has undoubtedly greater economic and social significance.
Disclosure of Invention
The invention provides a method for recovering cyanuric acid by catalytically degrading melamine resin, aiming at the problems that the added value of the product is low in the conventional mechanical treatment method and the product of a high-temperature pyrolysis method is difficult to recover.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for recovering cyanuric acid by catalytic degradation of melamine resin comprises the following steps:
crushing melamine resin materials into granules, immersing the granules into a catalyst-solvent liquid phase reaction system, reacting at 120-300 ℃, cooling to room temperature after the reaction is finished, and separating and recycling to obtain cyanuric acid. The invention realizes the catalytic degradation of melamine resin, the material is crushed, the mass transfer effect in the reaction process is convenient to improve, and the proper catalyst-solvent system is selected, so that the catalyst and the solvent can enter the material body and can be conveniently contacted with the active sites of the material reaction, and the catalytic degradation efficiency is further improved. Compared with the traditional treatment means, the method realizes the catalytic degradation of the melamine resin under mild conditions, and has simple product distribution and higher recovery rate. When the degradation temperature is lower than 120 ℃, the reaction rate of the reaction system is extremely low, and when the temperature is higher than 300 ℃, the yield of the cyanuric acid is not obviously improved.
Further, the particle size of the granules in the step is 0.05-10 mm. The particle size of the granules is too large, which not only affects mass transfer, but also increases the porosity of a reaction system, so that the solvent consumption is too large, which affects the degradation efficiency, and if the particle size is too small, the energy consumption is too high during crushing, the dust is more in the production process, and the economical efficiency is not good.
Further, the reaction time in the step is 90 min-48 h. When the reaction time is less than 90min, the melamine resin cannot be completely catalyzed and degraded by the above reaction system, and when the reaction time is more than 48h, the reaction of the melamine resin is not obviously promoted by the extension of the reaction time.
Further, the catalyst in said step is mainly an acidic catalyst. The selected acid catalyst can enter the material body more quickly in a liquid phase reaction system, and is convenient to contact with the material reaction active sites, so that the catalysis rate is improved.
Still further, the catalyst is HCl and HNO3、H3BO3、H2SO4、H2CO3、H3PO4、FeCl3、AlCl3、ZnCl2、CuCl2、MnCl2P-toluenesulfonic acid and dodecaneOne or more of the phenyl sulfonic acid is mixed according to any ratio. The catalyst selected by the technical scheme has a good catalytic effect on the catalytic degradation of melamine resin.
Still further, the solvent in the step is water or a mixed solution of water and an organic reagent, and the organic reagent is specifically one or more of methanol, ethanol, n-propanol, isopropanol, formic acid, acetic acid, tetrahydrofuran, diethyl ether, DMSO, dioxane, DMF, gamma-butyrolactone, gamma-valerolactone, acetone or ethylenediamine, which is mixed according to any ratio. The reaction solvent with strong reaction activity promotes the reaction of melamine resin through the action of the catalyst.
Still further, the mixed solution of water and an organic reagent in the step, wherein the volume ratio of water to the organic reagent is 1:0.5 to 10. By selecting a proper proportion, the mixed solvent has stronger reaction activity.
Further, the mass ratio of the catalyst to the melamine resin in the step is 1: 0.05-5; the mass ratio of the solvent to the melamine resin is 1-100: 1. The catalyst proportion range selected in the technical scheme has a good effect on the catalytic degradation of melamine resin, and the dissolution of the selected organic solvent and the recovered product cyanuric acid is low, so that the subsequent separation is facilitated.
Compared with the prior art, the invention has the following advantages:
the invention solves the problems of complex components of high-temperature pyrolysis products, easy generation of virulent hydrocyanic acid and the like in a chemical treatment method by carrying out chemical catalytic degradation on waste melamine tableware, and obtains cyanuric acid with high added value by directly adopting a catalyst-solvent system for reaction.
Drawings
FIG. 1 is an infrared spectrum of cyanuric acid of example 1 of the present invention;
FIG. 2 is cyanuric acid example 1 of the present invention13CNMR spectrogram;
FIG. 3 is an NMR chart of cyanuric acid of example 1 of the present invention.
Detailed Description
Example 1
1g of waste melamineThe tableware was pulverized into granules having a particle size of 10mm, and immersed in H2CO3Water, diethyl ether reaction System (H)2CO3The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 1:1, the volume ratio of water to diethyl ether in the solvent is 1: 0.5) reacting for 48 hours at 120 ℃ in a closed pressure container to fully react and degrade melamine resin materials, cooling to room temperature after the reaction is finished, filtering and washing to obtain 0.78g of cyanuric acid, wherein an infrared spectrogram of the cyanuric acid is shown in figure 1 in detail, wave numbers correspond to positions 833.56 and 3228.34 and are bending vibration and stretching vibration of an N-H bond on a cyanuric acid ring, wave numbers correspond to positions 1037 and are C-N bond stretching vibration in the ring, and wave numbers correspond to positions 1702.57 and 1482.33 and are symmetrical vibration and asymmetrical vibration of a C-O double bond;13the CNMR spectrum is detailed in FIG. 2, chemical shifts at 150.38ppm correspond to carbon within the cyanuric acid ring, and other peaks correspond to solvent; the NMR spectrum is detailed in FIG. 3, with chemical shifts at 11.23ppm corresponding to hydrogen in the cyanuric ring and other peaks corresponding to solvent.
Example 2
Pulverizing 1g waste melamine tableware into granules with particle size of 0.05mm, soaking in AlCl3Water, DMF reaction system (AlCl)3The mass ratio of the melamine resin to the melamine resin is 1: 0.05; the mass ratio of the solvent to the melamine resin is 80:1, the volume ratio of water to DMF in the solvent is 1: 5) reacting for 15h at 125 ℃ in a closed pressure vessel to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.87g of cyanuric acid.
Example 3
Pulverizing 1g of waste melamine tableware into granules with particle size of 5mm, and soaking in MnCl2Water, acetone reaction system (MnCl)2The mass ratio of the melamine resin to the melamine resin is 1: 3; the mass ratio of the solvent to the melamine resin is 100:1, the volume ratio of water to acetone in the solvent is 1: 6) reacting for 13h at 135 ℃ in a closed pressure container to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.85g of cyanuric acid.
Example 4
Pulverizing 1g of waste melamine tableware into granules with particle size of 6mm, and soaking in CuCl2Water, isopropanol (CuCl)2The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 50:1, the volume ratio of water to isopropanol in the solvent is 1: 5) reacting for 10h at 145 ℃ in a closed pressure vessel to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.88g of cyanuric acid.
Example 5
Crushing 1g of waste melamine tableware into granules with the particle size of 7.5mm, immersing the granules into a dodecylbenzene sulfonic acid-water-tetrahydrofuran reaction system (the mass ratio of dodecylbenzene sulfonic acid to melamine resin is 1: 0.5; the mass ratio of solvent to melamine resin is 10: 1; and the volume ratio of water in solvent to tetrahydrofuran is 1: 10), reacting for 90min at 300 ℃ in a closed pressure container, fully reacting and degrading the melamine resin material, cooling to room temperature after the reaction is finished, filtering and washing to obtain 0.85g of cyanuric acid.
Example 6
Pulverizing 1g of waste melamine tableware into granules with particle size of 2mm, and soaking in MnCl2Water, acetone reaction system (MnCl)2The mass ratio of the melamine resin to the melamine resin is 1: 3; the mass ratio of the solvent to the melamine resin is 100:1, the volume ratio of water to acetone in the solvent is 1: 6) reacting for 14h at 140 ℃ in a closed pressure container to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.85g of cyanuric acid.
Example 7
Pulverizing 1g of waste melamine tableware into granules with particle size of 3mm, and soaking in H3PO4Water, dioxane reaction System (H)3PO4The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 50:1, the volume ratio of water to dioxane in the solvent is 1: 5) reacting for 12h at 150 ℃ in a closed pressure vessel to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, filtering and washing to obtain the trimerization0.84g of cyanic acid.
Example 8
Crushing 1g of waste melamine tableware into granules with the particle size of 5mm, immersing the granules into a reaction system of HCl-water and methanol (the mass ratio of HCl to melamine resin is 1: 0.5; the mass ratio of solvent to melamine resin is 10: 1; and the volume ratio of water to methanol in the solvent is 1: 10), reacting for 23h in a closed pressure container at 150 ℃ to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.83g of cyanuric acid.
Example 9
Pulverizing 1g of waste melamine tableware into granules with particle size of 7mm, and soaking in H3PO4Water, ethanol reaction System (H)3PO4The mass ratio of the melamine resin to the melamine resin is 1: 1; the mass ratio of the solvent to the melamine resin is 20:1, the volume ratio of water to ethanol in the solvent is 1: 5) reacting for 21h at 155 ℃ in a closed pressure container to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.8g of cyanuric acid.
Example 10
Pulverizing 1g of waste melamine tableware into granules with particle size of 9mm, and soaking into FeCl3(FeCl) in a reaction System of Water and formic acid3The mass ratio of the melamine resin to the melamine resin is 1: 2; the mass ratio of the solvent to the melamine resin is 50:1, the volume ratio of water to formic acid in the solvent is 1: 8) reacting for 19h at 165 ℃ in a closed pressure container to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.81g of cyanuric acid.
Example 11
Pulverizing 1g of waste melamine tableware into granules with particle size of 8mm, and soaking the granules into ZnCl2Water, gamma-valerolactone reaction system (ZnCl)2The mass ratio of the melamine resin to the melamine resin is 1: 1; the mass ratio of the solvent to the melamine resin is 20:1, and the volume ratio of water to gamma-valerolactone in the solvent is 1: 5) reacting for 2h at 140 ℃ in a closed pressure container to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, filtering and washing to obtain the melamine resinCyanuric acid 0.75 g.
Example 12
Crushing 1g of waste melamine tableware into granules with the grain diameter of 8.5mm, immersing the granules into a reaction system of paratoluenesulfonic acid-water and acetic acid (the mass ratio of the toluenesulfonic acid to the melamine resin is 1:2, the mass ratio of the solvent to the melamine resin is 50:1, and the volume ratio of the water to the acetic acid in the solvent is 1: 8), reacting for 5 hours in a closed pressure container at 130 ℃ to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.84g of cyanuric acid.
Example 13
Pulverizing 1g of waste melamine tableware into granules with particle size of 9mm, and soaking in H2SO4Water, ethylenediamine reaction system (H)2SO4The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 80:1, and the volume ratio of water to ethylenediamine in the solvent is 1: 5) reacting for 8h at 110 ℃ in a closed pressure vessel to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.82g of cyanuric acid.
Example 14
Pulverizing 1g of waste melamine tableware into granules with particle size of 9.5mm, and soaking in H2SO4Water, gamma-valerolactone reaction system (H)2SO4The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 80:1, the volume ratio of water to gamma-valerolactone in the solvent is 1: 5) reacting for 12h at 160 ℃ in a closed pressure vessel to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.8g of cyanuric acid.
Example 15
Pulverizing 1g of waste melamine tableware into granules with particle size of 4.5mm, and soaking in MnCl2Water, acetone reaction system (MnCl)2The mass ratio of the melamine resin to the melamine resin is 1: 3; the mass ratio of the solvent to the melamine resin is 100:1, the volume ratio of water to acetone in the solvent is 1: 6) reacting for 16h at 165 ℃ in a closed pressure vessel to ensure that the melamine resin material fully reacts and reducesAnd (4) decomposing, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.87g of cyanuric acid.
Example 16
Pulverizing 1g of waste melamine tableware into granules with particle size of 10mm, and soaking in H3PO4Water, dioxane reaction System (H)3PO4The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 50:1, the volume ratio of water to dioxane in the solvent is 1: 5) reacting for 22h at 170 ℃ in a closed pressure container to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.8g of cyanuric acid.
Example 17
Pulverizing 1g of waste melamine tableware into granules with particle size of 1mm, and soaking in H2SO4Water, acetic acid reaction system (H)2SO4The mass ratio of the melamine resin to the melamine resin is 1: 5; the mass ratio of the solvent to the melamine resin is 80:1, and the volume ratio of water to acetic acid in the solvent is 1: 5) reacting for 18h at 180 ℃ in a closed pressure vessel to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.81g of cyanuric acid.
Example 18
Pulverizing 1g of waste melamine tableware into granules with particle size of 0.1mm, and soaking in HNO3Water, tetrahydrofuran reaction System (HNO)3The mass ratio of the melamine resin to the melamine resin is 1: 0.5; the mass ratio of the solvent to the melamine resin is 10:1, and the volume ratio of water to tetrahydrofuran in the solvent is 1: 10) reacting for 24h at 175 ℃ in a closed pressure container to ensure that the melamine resin material is fully reacted and degraded, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.8g of cyanuric acid.
Example 19
Pulverizing 1g of waste melamine tableware into granules with particle size of 0.2mm, and soaking in ZnCl2Water, DMSO reaction system (ZnCl)2The mass ratio of the melamine resin to the melamine resin is 1: 1; the mass ratio of the solvent to the melamine resin is 20:1, the volume ratio of water to DMSO in the solvent is 1: 5) in a closed pressure vesselReacting at 190 ℃ for 22h in the reactor to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.8g of cyanuric acid.
Example 20
Crushing 1g of waste melamine tableware into granules with the grain diameter of 0.5mm, immersing the granules into a reaction system of paratoluenesulfonic acid-water and acetic acid (the mass ratio of the toluenesulfonic acid to the melamine resin is 1:2, the mass ratio of the solvent to the melamine resin is 50:1, and the volume ratio of the water to the acetic acid in the solvent is 1: 8), reacting for 20 hours in a closed pressure container at 200 ℃ to fully react and degrade the melamine resin material, cooling to room temperature after the reaction is finished, and filtering and washing to obtain 0.82g of cyanuric acid.
Claims (8)
1. A method for recovering cyanuric acid by catalytic degradation of melamine resin is characterized in that: the method comprises the following steps:
crushing melamine resin materials into granules, immersing the granules into a catalyst-solvent liquid phase reaction system, reacting at 120-300 ℃, cooling to room temperature after the reaction is finished, and separating and recycling to obtain cyanuric acid.
2. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 1, wherein: the particle size of the granules in the step is 0.05-10 mm.
3. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 1, wherein: the reaction time in the step is 90 min-48 h.
4. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 1, wherein: the catalyst in said step is an acidic catalyst.
5. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 4, wherein: the acid catalyst is HCl and HNO3、H3BO3、H2SO4、H2CO3、H3PO4、FeCl3、AlCl3、ZnCl2、CuCl2、MnCl2One or more of p-toluenesulfonic acid and dodecylbenzene sulfonic acid are mixed according to any ratio.
6. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 1, wherein: the solvent in the step is water or a mixed solution of water and an organic reagent, and the organic reagent is specifically one or more of methanol, ethanol, n-propanol, isopropanol, formic acid, acetic acid, tetrahydrofuran, diethyl ether, DMSO, dioxane, DMF, gamma-butyrolactone, gamma-valerolactone, acetone or ethylenediamine which are mixed according to any ratio.
7. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 6, wherein: the volume ratio of the water to the organic reagent in the mixed solution of the water and the organic reagent in the step is 1:0.5 to 10.
8. The method for recovering cyanuric acid through catalytic degradation of melamine resin as claimed in claim 1, wherein: in the step, the mass ratio of the catalyst to the melamine resin is 1: 0.05-5; the mass ratio of the solvent to the melamine resin is 1-100: 1.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104909489A (en) * | 2015-04-27 | 2015-09-16 | 鄄城康泰化工有限公司 | Trichloroisocyanuric acid production technology sewage processing method |
| CN109415531A (en) * | 2016-04-05 | 2019-03-01 | 复合材料科技控股有限责任公司 | The recycling of polymeric matrix composite material |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104909489A (en) * | 2015-04-27 | 2015-09-16 | 鄄城康泰化工有限公司 | Trichloroisocyanuric acid production technology sewage processing method |
| CN109415531A (en) * | 2016-04-05 | 2019-03-01 | 复合材料科技控股有限责任公司 | The recycling of polymeric matrix composite material |
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