Treatment method for solid waste containing triphenylphosphine oxide

Abstract

The invention discloses a treatment method of solid waste containing triphenylphosphine oxide. The treatment method comprises the following steps: step (1): putting the solid waste containing triphenylphosphine oxide, an auxiliary agent and a solvent I into a reaction kettle; (2) adding chlorosilane into the reaction kettle, and carrying out reduction reaction to generate TPP; and (3) after the reaction is finished, quenching the reaction, and separating to obtain a reaction product. The purity of the obtained TPP is larger than 99.0%, the yield is larger than 95% and is higher than the industrial value by 90%, the by-product SiO2 can be directly sold as white carbon black, the process is easy to operate, resource utilization of solid waste is achieved, the production cost of vitamin A can be reduced by 15%, and the method has remarkable commercial value.

Description

Technical Field

[0001] This invention belongs to the field of solid waste treatment, and specifically relates to a method for treating triphenylphosphine oxide solid waste. Background Technology

[0002] Triphenylphosphine oxide (TPPO) is a white crystalline solid with almost no other uses besides its application as a phosphorus-containing flame retardant. It is primarily produced through the vitamin A industry chain. Literature reports that the current synthesis of vitamin A acetate mainly employs the C15+C5 route characterized by the Wittig reaction. Specifically, β-ionone is used as a raw material, which, after reaction conversion, undergoes a salt-forming reaction with organophosphorus compounds to generate a Wittig precursor. This precursor then reacts with pentaldehyde under strong alkaline conditions to undergo a Wittig reaction, producing vitamin A acetate while simultaneously generating an equivalent amount of TPPO as a byproduct. TPPO often appears pale yellow or brown due to the presence of some heavy component impurities. As a solid waste containing vitamin A, its phosphorus content makes solid waste treatment extremely costly.

[0003] Therefore, the solid waste generated from vitamin A production is not only costly to treat, but also lacks qualified environmental protection companies, which is one of the bottlenecks restricting the development of vitamin A in the industry.

[0004] In industrial applications, the mainstream approach to TPPO resource utilization is to react it with a reducing agent to produce high-value-added triphenylphosphine (hereinafter referred to as TPP). Depending on the reducing agent, the main routes are as follows: First, the phosgene method. Phosgene is first used to convert triphenylphosphine oxide into dichloride, which is then reduced to triphenylphosphine with red phosphorus, while simultaneously recovering the useful byproduct phosphorus trichloride. The equation is as follows:

[0005]

[0006] Because phosgene is highly toxic, its use requires special qualifications and high-quality equipment, resulting in high safety risks and high equipment costs for this method.

[0007] Second, the borane method. Aoester et al. used borane to reduce triphenylphosphine oxide. If a borane containing a BH bond is used, the reaction temperature is approximately 100°C; if a trisubstituted borane without a BH bond is used, the reaction temperature must be increased. The reaction generates a certain pressure and must be carried out in an autoclave. For example, the following reaction generates a maximum pressure of 3727.8 kPa with a yield of 96.2%. The equation is as follows:

[0008]

[0009] This approach requires high-pressure vessels and has not yet been industrialized.

[0010] Third, the silane method. The use of silanes as reducing agents was reported as early as 1964. For example, Fritzsche et al. used methylpolysiloxanes and phenylsilanes, reacting in hydrocarbon or ether solvents, or even without solvent, for 2-3 hours, yielding 65-91% yields. In 1978, Davis et al. reduced silane trichloride with equimolar amounts of butylamine or dihexylamine to obtain 94.3% product. In 1985, Lee et al. discovered that the above reaction could also proceed smoothly in inert halogenated hydrocarbon solvents at 50-250°C. The equation is as follows:

[0011]

[0012] Although this method offers mild reaction conditions and lower production costs compared to the phosgene and borane methods, it shows promise for industrial application. However, as described in patent CN110343133A, this method suffers from drawbacks such as low yield (~90%) and lengthy post-processing steps, requiring further optimization. In particular, the byproduct SiO2 produced in this process cannot be directly sold due to issues related to its color and TPP encapsulation.

[0013] Therefore, developing an efficient method for treating solid waste containing triphenylphosphine oxide produced by a vitamin A device has good economic value. Summary of the Invention

[0014] This invention provides a method for treating solid waste containing triphenylphosphine oxide, which prepares TPP by reducing TPPO with chlorosilane. The obtained TPP has high purity and high reaction yield, and the byproduct silica has even higher purity and better quality, realizing the resource utilization of solid waste and reducing the production cost of vitamin A by 15%.

[0015] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0016] A method for treating solid waste containing triphenylphosphine oxide includes the following steps:

[0017] Step (1): Add the solid waste containing triphenylphosphine oxide, the additives, and the solvent into the reaction vessel;

[0018] Step (2): Add chlorosilane to the reactor to undergo a reduction reaction and generate TPP;

[0019] Step (3): Quench the reaction after the reaction is complete and separate the reaction products.

[0020] Preferably, in step (1), the solid waste containing triphenylphosphine oxide is the solid waste containing triphenylphosphine oxide generated during the production of vitamin A.

[0021] Preferably, the solvent is one or more of toluene, m-xylene, o-xylene, p-xylene, mesitylene, and benzene, with toluene being the most preferred;

[0022] Preferably, the mass ratio of triphenylphosphine oxide to solvent one in the solid waste containing triphenylphosphine oxide is 1:(0.5-10), more preferably 1:(1-5).

[0023] Preferably, the adjuvant includes adjuvant A and adjuvant B, wherein adjuvant A is selected from one or both of compounds with the structure of formula (I) or formula (II), and adjuvant B is a compound with the structure of formula (III).

[0024]

[0025] The mass ratio of additive A to additive B is (0.1-20):1, preferably (0.2-10):1, and more preferably (1-5):1.

[0026] The amount of the additive added is 0.1%-10% of the mass of triphenyloxyphosphine in the solid waste containing triphenyloxyphosphine, preferably 1%-5%.

[0027] Preferably, in step (2), the chlorosilane is one or more of trichlorosilane, dichlorosilane, monochlorosilane, methyldichlorosilane, dimethylchlorosilane, etc., with trichlorosilane being the most preferred.

[0028] The molar amount of the chlorosilane added is 1-10 times, preferably 2-6 times, the molar amount of triphenylphosphine oxide in the solid waste containing triphenylphosphine oxide.

[0029] Preferably, the chlorosilane is slowly added to the reaction vessel, and the addition time of the chlorosilane is 0.1-10h, preferably 0.5-5h; in step (2), after the chlorosilane is added, the reaction is kept at a constant temperature for 1-10h, preferably 3-7h.

[0030] In step (2), the reaction temperature is 50-100℃, preferably 70-90℃;

[0031] In step (2), the reaction pressure is 0-5.0 MPaG, preferably 0-5.0 MPaG.

[0032] In step (2), the reaction stirring speed is 100-800 rpm, preferably 200-400 rpm.

[0033] Preferably, in step (3), solvent two is added to the reaction solution to quench the reaction. Preferably, solvent two is one or more of water, methanol, ethanol, propylene glycol, and n-butanol, preferably water. The amount of solvent two used is (0.1-5) times the total mass of triphenylphosphine oxide, auxiliaries, and chlorosilanes in the solid waste containing triphenylphosphine oxide, preferably (0.5-3).

[0034] In step (3), the quenching reaction temperature is 50-100℃, preferably 70-90℃;

[0035] In step (3), the quenching reaction pressure is 0-5.0 MPaG, preferably 0-5.0 MPaG.

[0036] In step (3), the quenching reaction is carried out under stirring conditions, with a stirring speed of 100-800 rpm, preferably 200-400 rpm.

[0037] After quenching, the reaction solution is centrifuged and allowed to stand for phase separation to obtain two phases containing solvent one and solvent two. The phase containing solvent one is then desolventized to obtain the final product TPP.

[0038] The phase containing solvent two is recycled.

[0039] The temperature for the static phase separation is 50-100℃, preferably 70-90℃;

[0040] The phase containing solvent one is obtained and then desolventized. The temperature for desolventizing solvent one is 100-400℃, preferably 150-200℃, and the pressure is 0-90KPaA, preferably 20-60KPaA.

[0041] The resulting phase containing solvent two is recycled to the next batch of quenching reactions.

[0042] In this invention, TPPO reacts with a reducing agent to generate TPP, while HCl and SiOCl2 are produced as byproducts. Taking trichlorosilane as an example, the chemical equation for the reaction is as follows:

[0043]

[0044] This application utilizes additives (Ⅰ), (Ⅱ), and (Ⅲ) to achieve unique technical advantages in this process. Specifically, compounds of formula (Ⅰ) and (Ⅱ) can react with the byproduct SiOCl2, continuously driving the main reaction 1 in the forward direction, thus achieving a conversion rate >99%. Compound (Ⅲ) reacts with the byproduct SiOCl2 to form a water-soluble polyolefin cyclic silica compound. This polyolefin cyclic silica compound disperses the byproduct SiO2, reducing the encapsulation rate of the product TPP in solid SiO2, thereby increasing the product separation yield and ensuring a SiO2 purity greater than 99.9%, allowing for direct sale.

[0045] The possible mechanisms of action of the additives are as follows:

[0046] Attached Figure Description

[0047] Figure 1 The image shows the 1H NMR spectrum of the synthesized compound of formula (Ⅰ).

[0048] Figure 2 The above is the 1H NMR spectrum of the synthesized compound of formula (II).

[0049] Figure 3 The above is the 1H NMR spectrum of the synthesized compound of formula (Ⅲ). Detailed Implementation

[0050] Main raw material sources

[0051] The solid waste containing triphenylphosphine oxide used in this invention is solid waste obtained by preparing vitamin A using the following method: β-vinyl ionone reacts with Grignard reagent to generate β-vinyl ionone; β-vinyl ionone reacts with triphenylphosphine to generate C15 phosphine salt; C15 phosphine salt reacts with pentacarbonaldehyde under strong alkali to undergo a Wittig reaction to obtain vitamin A.

[0052] Chlorosilanes such as trichlorosilane were purchased from Aladdin Reagent Co., Ltd.

[0053] The additives added during the reaction process are mainly synthesized using the following methods.

[0054] Both compounds of formula (I) and formula (II) were synthesized using method one.

[0055] The specific steps of Method 1 are as follows: Under a nitrogen atmosphere, 100g of a 18wt% tetrahydrofuran solution of vinyl magnesium chloride is added to a dry 0.5L reactor. Stirring is started and the reactor temperature is controlled at 10℃. Then, 50g of a 20wt% solution of 4-(2,6,6-trimethyl-1-cyclohexenyl)-3-buten-2-one is added, and the mixture is stirred at high speed and kept at this temperature for 9 hours. After the reaction is complete, the reactor temperature is lowered to -5℃, and a 10% dilute hydrochloric acid solution is added dropwise. The liquid phase is filtered and collected. After phase separation, the organic phase is desolventized and purified by crystallization in methanol at -5℃. The filtrate is concentrated to obtain substance I, with a liquid chromatography purity of 99.2%. This substance is then crystallized in a mixture of n-hexane and ethyl acetate at -10℃. The resulting solid is dried to obtain substance II, with a liquid chromatography purity of 99.1%. (Appendix) Figure 1 The 1H NMR spectrum of compound (I) is attached. Figure 2 The 1H NMR spectrum of compound (II) is shown. Taking compound (I) as an example, its 1H NMR spectrum was analyzed using a BRUKER 800 NMR spectrometer with an ULTRASHIED 400 magnet and TOPSPIN 3.0 software. The basic test conditions were: routine deuterated chloroform dilution at 25°C, and sample injection detection using a 5mm Dual NMR probe.

[0056] The compounds of formula (II) will not be described in detail.

[0057] In compound (I), chemical shifts of 1.25, 1.29, 1.96, and 2.21 represent hydrogens on the CH2 and terminal -CH3 groups of the cycloalkane, respectively, indicating that the substance has a certain cycloalkane structure; chemical shifts of 6.22, 6.49, and 6.57 represent hydrogens in non-terminal alkene double bonds, i.e., -CH=CH-, indicating that the substance has a straight-chain polyene structure; 4.99 and 5.11 are typical chemical shifts of terminal double bond hydrogens, i.e., -C=CH2; and the hydrogen at chemical shift 16.77 is a typical hydroxyl functional group.

[0058] Compound (III) was synthesized using method two, with partial reference to patent WO2013097286A1.

[0059] Method 2 involves the following steps: 288g of triphenylphosphine and 252g of vinyl pseudoionol are mixed with 1L of methanol. A methanol solution containing 96g of methanesulfonic acid (200mL volume) is added dropwise at 60℃. After the addition is complete, the mixture is kept at this temperature for 2 hours. After the reaction is complete, 100mL of deionized water is added to the system. The mixture is extracted three times with 500mL of n-hexane to remove the methanol solvent. It is then extracted with 2000mL of dichloromethane and washed three times with 5% sodium bromide aqueous solution to obtain the washed dichloromethane phase. After removing the dichloromethane solvent, ethyl acetate is added, and the mixture is cooled to crystallize. The resulting filtrate and solid are collected. 1mol (142g) of 2-methyl-4-acetoxy-2-butenal (99%, purchased from Shanghai Titan Technology Co., Ltd.) is added to the filtrate, along with 138g of potassium carbonate solid powder. The mixture is kept at 80℃ for 10 hours. After extraction with 400mL of n-hexane, the mixture is allowed to stand for phase separation. After removing the solvent from the obtained n-hexane phase, compound (III) was obtained with a liquid phase purity of 91.9%, and its proton NMR spectrum is shown below. Figure 3 .

[0060] Main testing methods

[0061] The analytical method is as follows. In this embodiment of the invention, the content (e.g., raw material TPPO, product TPP, etc.) and purity of each component are obtained by testing and calculation using the external standard method of a high-performance liquid chromatograph (Shimadzu LC-20AD). The conversion rate is calculated based on the content of the product. The liquid chromatography conditions are as follows: Column: Wärtsilä Select HSS T3, 4.6 μm × 250 mm; Injection volume: 2–10 μL, fine-tuned according to the sample conditions; Column temperature: 40 °C; Flow rate: 1 mL / min; Detector: Ultraviolet detector (UV), detection wavelength is 254–400 nm; Mobile phase: Acetonitrile / 0.1% phosphoric acid aqueous solution; When measuring the sample, a liquid external standard curve is first established with the pure product, and the mass fraction (content) of each detected substance is calculated based on the linear relationship between concentration and liquid phase peak area.

[0062] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Locational terms such as top and bottom, mentioned or possibly used in this specification, are defined relative to the constructions shown in the accompanying drawings; they are relative concepts and may therefore vary depending on their location and usage.

[0064] Example 1:

[0065] 2 mol (271 g) of trichlorosilane was accurately weighed under a nitrogen atmosphere and stored temporarily in a glove box at 5°C. TPPO solid waste from the Vitamin A apparatus was accurately weighed, and the calculated TPPO content was 278 g. This was poured into a 5L three-necked flask, and 278 g of solvent I (toluene) was added. Finally, 13.9 g of an additive mixture (5.0% of the solid waste mass) was added, with the mass ratio of the compound of formula (I), formula (II), and formula (III) in the additive mixture being 1:1:1. The stirring speed was set to 400 rpm, and the oil bath was set to an external temperature of 90°C to ensure the system temperature in the three-necked flask was 70°C (a 20°C temperature difference between the inside and outside). A diaphragm pump was used to create negative pressure to ensure the system pressure was 0 MPaG. The flow rate of the peristaltic pump was adjusted, and the weighed trichlorosilane was slowly added dropwise to the reaction vessel, maintaining constant temperature, pressure, and stirring speed during the addition process. The dropping time was controlled at 0.5 h. After the dropping was completed, the reaction was continued at 70 °C, 0 MPaG, and 400 rpm for 3 h.

[0066] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 281g of deionized water (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction liquid was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquid obtained by centrifugation consisted of an oil phase containing toluene and a water phase. The oil phase containing toluene was desolventized at 150℃ and 20 kPaA to obtain 256.8g of the final product. The water phase was recycled for the next batch of quenching reactions.

[0067] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.91%, the purity of the obtained TPP was 99.6%, and the yield was 98.0%. This achieved the resource utilization of solid waste and reduced the production cost of vitamin A by 15%.

[0068] Example 2:

[0069] Accurately weigh 10 mol (1355 g) of trichlorosilane under a nitrogen atmosphere and store it temporarily in a glove box at 5°C. Accurately weigh the solid waste TPPO obtained from the vitamin A unit; the calculated mass of TPPO contained in it is 278 g. Pour it into a 5 L stainless steel reactor, and then add 139 g of solvent one, which is m-xylene. Finally, add 0.278 g of the auxiliary agent mixture (0.1% of the solid waste mass), with the mass ratio of the compound of formula (I), the compound of formula (II), and the compound of formula (III) in the auxiliary agent mixture being 0.1:0.1:1. Set the stirring speed to 100 rpm, turn on the heating switch, set the external temperature to 70°C, and ensure the system temperature is 50°C (a 20°C temperature difference is required between the inside and outside). Open the nitrogen valve and introduce a certain amount of nitrogen into the system, ensuring the system pressure is 5.0 MPaG. Adjust the flow rate of the peristaltic pump and slowly add the weighed chlorosilane dropwise into the reactor. During the dropwise addition, maintain constant temperature, pressure, and stirring speed. Control the dropwise addition time to 10 hours. After the dropwise addition is completed, continue the reaction at 50°C, 5.0 MPaG, and 100 rpm for another hour.

[0070] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 163.3 g of methanol (solvent two) was weighed and added to the reactor in one go to quench the reaction. The resulting quenched reaction solution was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquids obtained by centrifugation consisted of an oil phase containing m-xylene and a phase containing methanol. The oil phase containing m-xylene was desolventized at 100℃ and 0 kPaA to obtain 252.1 g of the final product.

[0071] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.41%, the purity of the obtained TPP was 99.3%, and the yield was 97.8%.

[0072] Example 3:

[0073] Accurately weigh 8 mol (808 g) of dichlorosilane under a nitrogen atmosphere and store it temporarily in a glove box at 5°C. Accurately weigh the solid waste TPPO obtained from the vitamin A unit; after testing, the calculated TPPO content is 278 g. Pour this into a 5 L stainless steel reactor, and then add 1113.8 g of solvent one (o-xylene). Finally, add 27.8 g of an auxiliary agent mixture (10% of the raw material solid waste mass). The mass ratio of the compound with structure (I), structure (II), and structure (III) in the auxiliary agent mixture is 5:5:1. Set the stirring speed to 800 rpm, turn on the heating switch, set the external temperature to 120°C, and ensure the system temperature is 100°C (a 20°C temperature difference is required between the inside and outside). Open the nitrogen valve and introduce a certain amount of nitrogen into the system, ensuring the system pressure is 1.0 MPaG. Adjust the flow rate of the peristaltic pump and slowly add the weighed chlorosilane dropwise into the reactor. During the dropwise addition, maintain constant temperature, pressure, and stirring speed. Control the dropwise addition time to 8 hours. After the dropwise addition is completed, continue the reaction at 100℃, 1.0 MPaG, and 800 rpm for another 10 hours.

[0074] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 5569g of ethanol (solvent two) was weighed and added to the reactor in one go to quench the reaction. The resulting quenched reaction solution was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquids obtained by centrifugation consisted of an oil phase containing o-xylene and a phase containing ethanol. The oil phase containing o-xylene was desolventized at 400℃ and 60 kPaA to obtain 245.6g of the final product.

[0075] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 100%, the purity of the obtained TPP was 99.1%, and the yield was 97.4%.

[0076] Example 4:

[0077] Accurately weigh 6 mol (774 g) of methyldichlorosilane under a nitrogen atmosphere and store it temporarily in a glove box at 5°C. Accurately weigh the solid waste TPPO obtained from the vitamin A unit; after testing, the calculated TPPO content is 278 g. Pour this into a 5 L stainless steel reactor, and then add 1390 g of solvent one (paraxylene). Finally, add 13.9 g of an auxiliary agent mixture (5% of the raw material solid waste mass). The mass ratio of the compound with structure (I), structure (II), and structure (III) in the auxiliary agent mixture is 2.5:2.5:1. Set the stirring speed to 600 rpm, turn on the heating switch, set the external temperature to 100°C, and ensure the system temperature is 80°C (a 20°C temperature difference is required between the inside and outside). Open the nitrogen valve and introduce a certain amount of nitrogen into the system, ensuring the system pressure is 3.0 MPaG. Adjust the flow rate of the peristaltic pump and slowly add the weighed chlorosilane dropwise into the reactor. During the dropwise addition, maintain constant temperature, pressure, and stirring speed. Control the dropwise addition time to 5 hours. After the dropwise addition is completed, continue the reaction at 80℃, 3.0 MPaG, and 600 rpm for another 7 hours.

[0078] After the heat preservation reaction was completed, while maintaining constant temperature, pressure, and stirring speed, 3197.7g of propylene glycol (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction solution was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquids obtained by centrifugation consisted of an oil phase containing p-xylene and a phase containing propylene glycol. The oil phase containing p-xylene was desolventized at 200℃ and 90KPaA to obtain 240.4g of the final product.

[0079] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.0%, the purity of the obtained TPP was 99.5%, and the yield was 97.9%.

[0080] Example 5:

[0081] Under a nitrogen atmosphere, accurately weigh 4 mol (266 g) of dimethylchlorosilane and store it temporarily in a glove box at 5°C. Accurately weigh the solid waste TPPO obtained from the vitamin A unit; after testing, the calculated mass of TPPO contained in it is 278 g. Pour it into a 5 L stainless steel reactor, and then add 834 g of solvent one, which is benzene. Finally, add 2.78 g of auxiliary agent mixture (1% of the mass of the raw solid waste). The mass ratio of the compound with structure (I), structure (II), and structure (III) in the auxiliary agent mixture is 1.5:1.5:1. Set the stirring speed to 300 rpm, turn on the heating switch, set the external temperature to 80°C, and ensure the system temperature is 60°C (a 20°C temperature difference is required between the inside and outside). Open the nitrogen valve and introduce a certain amount of nitrogen into the system, ensuring the system pressure is 2.0 MPaG. Adjust the flow rate of the peristaltic pump and slowly add the weighed chlorosilane dropwise into the reactor. During the dropwise addition, maintain constant temperature, pressure, and stirring speed. Control the dropwise addition time to 3 hours. After the dropwise addition is completed, continue the reaction at 60℃, 2.0 MPaG, and 300 rpm for another 7 hours.

[0082] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 1093.6 g of n-butanol (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction solution was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquids obtained by centrifugation consisted of an oil phase containing benzene and a phase containing n-butanol. The benzene-containing oil phase was desolventized at 250℃ and 30 kPaA to obtain 233.7 g of the final product.

[0083] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.3%, the purity of the obtained TPP was 99.7%, and the yield was 97.2%.

[0084] Example 6

[0085] The main difference between this embodiment and Example 1 is that the composition of the adjuvant is a compound with structure (I) and a compound with structure (III) in a mass ratio of 1:1.

[0086] 2 mol (271 g) of trichlorosilane was accurately weighed under a nitrogen atmosphere and placed in a glove box at 5°C for temporary storage. TPPO solid waste from the vitamin A apparatus was accurately weighed, and the calculated TPPO content was 278 g. This was poured into a 5L three-necked flask, and 278 g of solvent I (toluene) was added. Finally, 13.9 g of an auxiliary agent mixture (5.0% of the solid waste mass) was added, with a mass ratio of compound of formula (I) to compound of formula (III) of 1:1. The stirring speed was set to 400 rpm, and the oil bath was set to an external temperature of 90°C to ensure the system temperature in the three-necked flask was 70°C (a 20°C temperature difference between inside and outside). A diaphragm pump was used to create negative pressure to ensure the system pressure was 0 MPaG. The flow rate of the peristaltic pump was adjusted, and the weighed trichlorosilane was slowly added dropwise to the reaction vessel, maintaining constant temperature, pressure, and stirring speed during the addition process. The dropping time was controlled at 0.5 h. After the dropping was completed, the reaction was continued at 70 °C, 0 MPaG, and 400 rpm for 3 h.

[0087] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 281g of deionized water (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction liquid was centrifuged and allowed to stand for phase separation. The solid obtained by centrifugation was white particulate matter SiO2, which could be sold to manufacturers of silica. The liquid obtained by centrifugation consisted of an oil phase containing toluene and a water phase. The oil phase containing toluene was desolventized at 150℃ and 20 kPaA to obtain 256.8g of the final product. The water phase was recycled for the next batch of quenching reactions.

[0088] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.91%, the purity of the obtained TPP was 99.3%, and the yield was 97.5%.

[0089] Example 7

[0090] The main difference between this embodiment and Example 1 is that the composition of the adjuvant is a compound with structure (I) and a compound with structure (II) in a mass ratio of 1:1.

[0091] 2 mol (271 g) of trichlorosilane was accurately weighed under a nitrogen atmosphere and placed in a glove box at 5°C for temporary storage. TPPO solid waste from the vitamin A apparatus was accurately weighed, and after testing, it was calculated to contain 278 g of TPPO. This was poured into a 5L three-necked flask, and 278 g of solvent I (toluene) was added. Finally, 13.9 g of an auxiliary agent mixture (5.0% of the solid waste mass) was added, with the mass ratio of the compound of formula (I) to the compound of formula (II) in the auxiliary agent mixture being 1:1. The stirring speed was set to 400 rpm, and the oil bath was set to an external temperature of 90°C to ensure the system temperature in the three-necked flask was 70°C (a 20°C temperature difference between the inside and outside). A diaphragm pump was used to create negative pressure to ensure the system pressure was 0 MPaG. The flow rate of the peristaltic pump was adjusted, and the weighed trichlorosilane was slowly added dropwise to the reaction vessel, maintaining constant temperature, pressure, and stirring speed during the addition process. The dropping time was controlled at 0.5 h. After the dropping was completed, the reaction was continued at 70 °C, 0 MPaG, and 400 rpm for 3 h.

[0092] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 281g of deionized water (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction liquid was centrifuged and allowed to settle for phase separation. The solid obtained by centrifugation was pale white particulate matter SiO2. Sampling analysis showed that the SiO2 contained 1.0wt% TPP. The liquid obtained by centrifugation consisted of an oil phase containing toluene and a water phase. The oil phase containing toluene was desolventized at 150℃ and 20KPaA to obtain 256.8g of the final product. The water phase was recycled for the next batch of quenching reactions.

[0093] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 99.01%, the purity of the obtained TPP was 99.2%, and the yield was 90.5%.

[0094] Comparative Example 1

[0095] Compared with Example 1, no additives were added, and all other process conditions were the same. The reduction reaction of TPPO to TPP was carried out, as follows.

[0096] Accurately weigh 2 mol (271 g) of trichlorosilane under a nitrogen atmosphere and store it in a 5°C glove box for later use. Accurately weigh TPPO solid waste from the Vitamin A unit; calculations show it contains 278 g of TPPO. Pour this into a 5L three-necked flask, and add 278 g of solvent one (toluene). Set the stirring speed to 400 rpm and the oil bath to 90°C to maintain a system temperature of 70°C in the three-necked flask (a 20°C temperature difference between the inside and outside). Use a diaphragm pump to create negative pressure, ensuring a system pressure of 0 MPaG. Adjust the flow rate of the peristaltic pump and slowly add the weighed trichlorosilane dropwise into the reactor, maintaining constant temperature, pressure, and stirring speed during the addition. Control the addition time to 0.5 h. After the addition is complete, continue the reaction at 70°C, 0 MPaG, and 400 rpm for 3 h.

[0097] After the heat preservation reaction was completed, the temperature, pressure, and stirring speed were kept constant. 281g of deionized water (solvent two) was weighed and added to the reactor in one go for quenching. The resulting quenched reaction liquid was centrifuged and allowed to settle for phase separation. The solid obtained by centrifugation was pale yellow particulate matter SiO2, and the liquid obtained by centrifugation consisted of an oil phase containing toluene and a water phase. The oil phase containing toluene was desolventized at 150℃ and 20 kPaA to obtain 256.8g of the final product. The water phase was recycled for the next batch of quenching reactions.

[0098] After the reaction was completed, samples were taken for analysis. The conversion rate of the raw material TPPO was 85.9%, the purity of the obtained TPP was 99.3%, and the yield was 86.3%.

[0099] As shown in Comparative Example 1, when no additives are added during the reaction, the reaction conversion rate decreases to 85.9% because the byproduct SiOCl2 is not quenched in time. Furthermore, without additives, the water-soluble polyolefin silica compounds in the additives are sufficient to disperse the byproduct SiO2, resulting in a pale yellow solid containing TPPO and TPP, making the obtained SiO2 unsuitable for direct sale as a byproduct.

[0100] 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 method for treating solid waste containing triphenylphosphine oxide, characterized in that: The following steps are involved: Step (1): putting solid waste containing triphenylphosphine oxide, an auxiliary agent and a solvent into a reaction kettle; Step (2): adding chlorosilane to the reaction kettle to generate TPP by reduction reaction; Step (3): After the reaction is completed, the reaction is quenched and the reaction product is separated.

2. The processing method according to claim 1, characterized in that: In step (1), the solid waste containing triphenylphosphine oxide is the solid waste containing triphenylphosphine oxide generated in the production of vitamin A; Preferably, the solvent 1 is one or more of toluene, m-xylene, o-xylene, p-xylene, mesitylene, and benzene, preferably toluene; Preferably, the mass ratio of triphenylphosphine oxide to solvent one in the triphenylphosphine oxide-containing solid waste is 1:(0.5-10), preferably 1:(1-5).

3. The processing method according to claim 1 or 2, characterized in that: The auxiliary agent includes auxiliary agent A and auxiliary agent B, wherein auxiliary agent A is selected from one or both of the compound of formula (I) or the compound of formula (II), and auxiliary agent B is the compound of formula (III). Wherein, the mass ratio of auxiliary agent A to auxiliary agent B is (0.1-20):1, preferably (0.2-10):1, more preferably (1-5):1; Preferably, the amount of the auxiliary agent added is 0.1%-10% of the mass of triphenylphosphine oxide in the solid waste containing triphenylphosphine oxide, preferably 1%-5%.

4. The processing method according to any one of claims 1 to 3, characterized in that: In step (2), the chlorosilane is one or more of trichlorosilane, dichlorosilane, monochlorosilane, methyldichlorosilane, and dimethylchlorosilane, preferably trichlorosilane; Preferably, the molar amount of the chlorosilane added is 1-10 times, preferably 2-6 times, the molar amount of triphenylphosphine oxide in the solid waste containing triphenylphosphine oxide; Preferably, the chlorosilane is slowly added into the reaction kettle, and the adding time of the chlorosilane is 0.1-10h, preferably 0.5-5h; Preferably, in step (2), after the addition of chlorosilane is completed, the reaction is continued by heat preservation, and the reaction time is 1-10 hours, preferably 3-7 hours; Preferably, in step (2), the reaction temperature is 50-100°C, preferably 70-90°C; Preferably, in step (2), the reaction pressure is 0-5.0 MPaG, preferably 0-5.0 MPaG; Preferably, in step (2), the reaction stirring speed is 100-800 rpm, preferably 200-400 rpm.

5. The processing method according to any one of claims 1 to 4, characterized in that: In step (3), adding solvent 2 to the reaction solution to quench the reaction; Preferably, the second solvent is one or more of water, methanol, ethanol, propylene glycol, and n-butanol, preferably water; Preferably, the amount of the second solvent used is (0.1-5) times the total mass of triphenylphosphine oxide, auxiliary agent and chlorosilane in the solid waste containing triphenylphosphine oxide, preferably (0.5-3).

6. The processing method according to any one of claims 1 to 5, characterized in that: In step (3), the quenching reaction temperature is 50-100°C, preferably 70-90°C; Preferably, in step (3), the quenching reaction pressure is 0-5.0 MPaG, preferably 0-5.0 MPaG; Preferably, in step (3), the quenching reaction is carried out under stirring conditions, and the stirring speed is 100-800 rpm, preferably 200-400 rpm.

7. The processing method according to any one of claims 1 to 6, characterized in that: The quenched reaction solution is centrifuged and allowed to stand for phase separation to obtain two phases containing solvent one and solvent two. The phase containing solvent one is desolvated to obtain the final product TPP, and the phase containing solvent two is recycled; Preferably, the temperature of the static phase separation is 50-100°C, preferably 70-90°C; Preferably, a phase containing solvent 1 is obtained for desolventizing, wherein the temperature for removing solvent 1 is 100-400° C., preferably 150-200° C., and the pressure is 0-90 KPaA, preferably 20-60 KPaA; Preferably, the obtained phase containing solvent 2 is recycled and applied to the next batch of quenching reactions.

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