Tributyl phosphate catalytic decomposition method

Abstract

The invention discloses a catalytic decomposition method of tributyl phosphate. The preparation method comprises the following steps: firstly, polymerizing p-toluenesulfonic acid and paraformaldehyde under the catalytic action of sulfuric acid to prepare a powdery paraformaldehyde sulfonic acid catalyst; then adding tributyl phosphate, normal octane and a powdery paraformaldehyde sulfonic acid catalyst into the spherical reactor, heating to 100-140 DEG C, and stirring for reaction; connecting a water segregator to the reactor, and condensing and collecting light components and water after reaction; in the reaction process, the content of the tributyl phosphate in the reactor is detected by adopting a gas chromatographic analysis method, and the tributyl phosphate can be completely catalytically decomposed after the reaction is carried out for a certain time. By adopting a heterogeneous catalysis method, the conversion rate of catalyzing the decomposition of the tributyl phosphate is high; the used powder paraformaldehyde sulfonic acid catalyst is simple in preparation process and can be recycled for multiple times through separation after the reaction is finished; the method disclosed by the invention is beneficial to catalytic decomposition application of the tributyl phosphate waste liquid in industry.

Description

Technical Field

[0001] The invention relates to the field of environmental protection, and in particular to a catalytic decomposition method of organic waste liquid containing tributyl phosphate and application thereof. Background Art

[0002] Tributyl phosphate (TBP, (C4H9O)3PO) is widely used as an organic solvent or extractant. In the hydrometallurgical industry, especially in the extraction and separation of rare earth elements, TPB is widely used to extract and separate rare earth elements such as ytterbium and scandium (CN202210885384.4); in salt lake chemical industry, TPB is used as an extractant for metallic lithium (Chemical Analysis and Metering, 2024, 33(03): 94-98+104); however, there is still a lack of efficient degradation treatment methods for TPB organic waste liquid after extraction application, except for incineration treatment.

[0003] In addition to the above-mentioned extraction and separation applications of metal elements in the metallurgical field, another important use of TPB extractant is as an extractant for radioactive elements such as uranium and plutonium in the PUREX process; in the PUREX process nuclear fuel reprocessing, TPB is mainly used as an extractant, and long-chain alkanes, hydrogenated kerosene and other alkane hydrocarbons are used as diluents. During the extraction operation, the extract containing TPB is circulated with an initial solution, washing solution, stripping solution and regeneration solution containing nitric acid and radioactive substances (uranium and plutonium) to extract and separate radioactive elements such as uranium and plutonium. After the extraction absorption dose exceeds 1mGy, the properties of the extract will undergo irreversible changes, that is, the extraction selectivity, extraction capacity and fluid dynamics will significantly decrease; at this time, the extract containing TPB will need to be updated. It is worth noting that researchers have repeatedly tried to treat the spent extractant by separating radioactive impurities or regenerating the extractant (Patent RU 2302677, 10.07.2007); however, in the process of regenerating the spent extractant and separating radioactive impurities, other complex radioactive mixtures are easily formed, resulting in no effective method for regenerating and reusing the spent extractant. The incineration process of radioactive spent TPB extract will cause the spread of radioactive substances. So far, a large amount of TPB waste liquid containing radioactive residues has been mainly stored in cans. Therefore, it is urgent to develop a safe and efficient TPB decomposition treatment method.

[0004] In view of the bottleneck problem of decomposition and treatment of the above-mentioned TPB extraction waste liquid, the present invention provides a chemical catalytic decomposition method for efficiently catalyzing the efficient decomposition of TPB in organic waste liquid. The decomposed aqueous inorganic phosphorus-containing matter can be landfilled after vitrification treatment; the organic components can be recycled and reused or further incinerated. Summary of the invention

[0005] The invention provides a catalytic decomposition method for tributyl phosphate-containing organic waste liquid (as shown in the following formula), which comprises providing a preparation method of a high-performance powdered polyformaldehyde sulfonic acid catalyst.

[0006]

[0007] In order to solve the technical problem of the present invention, the following technical solution is adopted:

[0008] A method for catalytic decomposition of tributyl phosphate: a certain amount of tributyl phosphate, n-octane and powdered polyformaldehyde sulfonic acid catalyst are added into a spherical reactor, the reaction temperature is set, and the catalytic decomposition reaction of tributyl phosphate is carried out under vigorous stirring, and the reaction conversion rate of tributyl phosphate is analyzed by gas chromatograph, and the composition of decomposition products is analyzed by gas chromatography-mass spectrometry.

[0009] The reaction is carried out in n-octane solvent.

[0010] The reaction temperature is 100-140° C., and the reaction time is 3-6 hours.

[0011] The reaction system comprises 20 g of catalyst, 50 mL of tributyl phosphate and 100 mL of n-octane.

[0012] The decomposition products of tributyl phosphate are butanol, butene, isomeric octenes and phosphoric acid.

[0013] The reactor is a spherical reactor, the upper end of which is connected to a water separator to condense and collect the light components and water after the reaction.

[0014] The specific preparation method of the powdered polyformaldehyde sulfonic acid catalyst is as follows: 200g of polyformaldehyde and 100g of p-toluenesulfonic acid are added to a 1000mL three-necked flask; then, 5g of concentrated sulfuric acid with a mass concentration of 98% is added, and the mixture is stirred and reacted at 100-120°C for 48h; the obtained black solid powder is washed with deionized water at 90°C until SO4 2- All of them were removed; finally, the mixture was dried in a vacuum drying oven at 60°C overnight to obtain a powdered polyformaldehyde sulfonic acid catalyst.

[0015] Advantages of the present invention:

[0016] 1. The present invention adopts a multiphase catalytic method, and the catalytic decomposition conversion rate of tributyl phosphate is high; the decomposition products are mainly butanol, butene, isooctenes and phosphorus-containing inorganic substances, etc.; phosphorus-containing inorganic substances such as phosphoric acid can be vitrified and landfilled, and the organic components can be recycled or further incinerated.

[0017] 2. The powdered polyformaldehyde sulfonic acid catalyst used in the present invention has a simple preparation process and can be recycled multiple times after separation after the reaction is completed; the method of the present invention is conducive to the safe and green catalytic decomposition treatment of tributyl phosphate waste liquid in industry.

[0018] Description of the attached figure

[0019] Figure 1 Infrared spectrum of solid polyformaldehyde sulfonic acid catalyst;

[0020] Figure 2 Schematic diagram of the catalytic decomposition and recycling effect of tributyl phosphate. DETAILED DESCRIPTION

[0021] Example 1

[0022] A method for catalytic decomposition of tributyl phosphate, the specific method is as follows: 200g of polyformaldehyde and 100g of p-toluenesulfonic acid are added to a 1000mL three-necked flask; then, 5g of concentrated sulfuric acid with a mass concentration of 98% is added, and the mixture is stirred and reacted at 100-120°C for 48h; the obtained black solid powder is washed with deionized water at 90°C until SO4 2- Finally, the catalyst was dried overnight in a vacuum oven at 60°C to obtain a powdered polyformaldehyde sulfonic acid catalyst. Figure 1 This indicates that the polyformaldehyde sulfonic acid catalyst has abundant sulfonic acid sites.

[0023] Example 2

[0024] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 110 DEG C, the reaction is carried out for 4 hours, and the conversion rate of tributyl phosphate in the reaction system is 78% according to gas chromatography analysis.

[0025] Example 3

[0026] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 120 DEG C, the reaction is carried out for 4 hours, and the conversion rate of tributyl phosphate in the reaction system is 83.6% according to gas chromatography analysis.

[0027] Example 4

[0028] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 125° C., the reaction is carried out for 4 hours, and the conversion rate of tributyl phosphate in the reaction system is 89.2% according to gas chromatography analysis.

[0029] Example 5

[0030] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 130 DEG C, the reaction is carried out for 4 hours, and the conversion rate of tributyl phosphate in the reaction system is 97.4% according to gas chromatography analysis.

[0031] Example 6

[0032] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 135° C., the reaction is carried out for 4 hours, and the conversion rate of tributyl phosphate in the reaction system is 99.1% as analyzed by gas chromatography.

[0033] Example 7

[0034] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 130 DEG C, the reaction is carried out for 3 hours, and the conversion rate of tributyl phosphate in the reaction system is 89.8% according to gas chromatography analysis.

[0035] Example 8

[0036] A method for catalytic decomposition of tributyl phosphate is disclosed. The specific method is as follows: 20 g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50 mL of tributyl phosphate and 100 mL of n-octane are added into a 250 mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 130 DEG C, the reaction is carried out for 5 hours, and the conversion rate of tributyl phosphate in the reaction system is 98.9% according to gas chromatography analysis.

[0037] Example 9

[0038] A method for catalytic decomposition of tributyl phosphate, the specific method is as follows: 20g of the powdered polyformaldehyde sulfonic acid catalyst in Example 1, 50mL of tributyl phosphate, and 100mL of n-octane are added into a 250mL spherical reactor, the upper end of the reactor is connected with a water separator, the function of the water separator is to collect water and other light component products after catalytic decomposition, the heating temperature is set to 130°C, the reaction is carried out for 6h, and the conversion rate of tributyl phosphate in the reaction system is 99.7% by gas chromatography analysis. The light components in the water separator are analyzed by gas chromatography-mass spectrometry to be butanol, isomeric carbon octaolefins, isomeric carbon dodecenes, butenes, etc.

[0039] Example 10

[0040] A method for catalytic decomposition of tributyl phosphate, the specific method is as follows: after the tributyl phosphate is catalytically decomposed for 6 hours in Example 9, 50 mL of tributyl phosphate is continuously added, and the catalytic decomposition reaction is carried out at 130° C. for 6 hours. The reaction is repeated 10 times, and the catalytic decomposition conversion rate of tributyl phosphate is higher than 98%.

Claims

1. A method for catalytic decomposition of tributyl phosphate, characterized in that: Firstly, p-toluenesulfonic acid and polyformaldehyde are polymerized under the catalytic action of sulfuric acid to form a powdery polyformaldehyde sulfonic acid catalyst; then, the powdery polyformaldehyde sulfonic acid catalyst is used to catalyze the decomposition of tributyl phosphate.

2. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: 200g of polyformaldehyde and 100g of p-toluenesulfonic acid were added to a 1000mL three-necked flask; then, 5g of 98% concentrated sulfuric acid was added and stirred at 100-120°C for 48h; the obtained black solid powder was washed with deionized water at 90°C until SO4 2- All of them were removed; finally, the mixture was dried in a vacuum drying oven at 60°C overnight to obtain a powdered polyformaldehyde sulfonic acid catalyst.

3. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: The prepared powdered polyformaldehyde sulfonic acid catalyst contains abundant sulfonic acid group strong acid catalytic sites.

4. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: The prepared powdered polyformaldehyde sulfonic acid catalyst catalyzes the decomposition of tributyl phosphate in n-octane solvent, the reaction temperature is 100-140 DEG C, and the reaction time is 3-6 hours.

5. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: The reactor is a spherical reactor, the upper end of which is connected to a water separator to condense and collect the light components and water after the reaction.

6. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: The dosage of the catalyst is 20 g, tributyl phosphate is 50 mL, and n-octane is 100 mL; the catalytic decomposition products of tributyl phosphate are mainly butanol, butene, isooctenes and phosphoric acid.

7. A method for catalytic decomposition of tributyl phosphate according to claim 1, characterized in that: The powdered polyformaldehyde sulfonic acid catalyst can be filtered, recovered and reused in the decomposition reaction of tributyl phosphate. It can be reused 10 times and the catalytic activity remains stable.

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