Continuous flow hydrolysis method for phosphate ester and phosphite ester compound based on micro-reaction system

Abstract

To provide a continuous flow hydrolysis method for phosphate ester and phosphite ester compounds based on a micro-reaction system.SOLUTION: High-purity phosphoric acid or phosphorous acid compounds are obtained by taking phosphate ester or phosphite ester compounds as raw materials and using a continuous micro-reaction system formed by connecting a micro-mixer, a micro-channel reactor, a back pressure valve and a gas-liquid separator through pipelines.EFFECT: By using a micro-reaction system in comparison with a traditional batch kettle type synthesis method, the method achieves high reaction efficiency, stable product quality, an order-of-magnitude increase in production capacity per unit reactor volume, and, because the reaction system is closed, avoids volatilization of organic matter and is environmentally friendly and non-toxic during the production process.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention belongs to the technical field of organic chemistry, and specifically relates to a continuous flow hydrolysis method for phosphate and phosphite compounds. [Background technology]

[0002] The continuous-flow hydrolysis process for phosphate and phosphite ester compounds mainly consists of acid addition, desolvation, and deoxidation steps. Because the production process proceeds in an intermittent, step-by-step fashion, each step requires a set temperature, time, and material ratio, resulting in high operational demands and difficulty. Traditional production is accomplished using conventional instruments and manual operation, resulting in high labor intensity, complex control, unstable quality, low continuity, significant human and material consumption, and high costs. Furthermore, the use of a kettle-type reactor during the production process is prone to solvent and product leakage, creating a strong odor in the production environment, which is contrary to environmentally friendly development principles. Therefore, the continuous-flow hydrolysis process for phosphate and phosphite ester compounds was technically modified using microchannel reactor control technology to achieve real-time control and management of the production process. Implementation of this technology significantly reduces worker labor intensity and consumption, ensures product quality, and improves production efficiency. The microchannel control system for continuous flow hydrolysis of phosphate and phosphite compounds mainly consists of subsystems such as a pressurized feed pump, a micromixer, a microchannel reactor, and a gas-liquid separator, and has achieved satisfactory results in actual use.

[0003] Prior art documents and patents CN102516293A, CN110860310A, and CN116078339A disclose one-step kettle hydrolysis of phosphite esters, but they mainly focus on the kettle continuous hydrolysis of methyl phosphite, and the degree of continuity is still low, the required reaction time is long, which leads to increased costs and remains a major problem for industrial production. Summary of the Invention

[0004] In order to overcome the drawbacks of the prior art, such as the long reaction time in the hydrolysis process of phosphate or phosphite compounds, the low conversion rate of raw materials, the high production safety risk, the large amount of three wastes (exhaust gas, wastewater, and solid waste) discharged, and the high energy consumption, the present invention provides a method for the continuous hydrolysis of phosphate or phosphite compounds based on a micro-reactor system.

[0005] The method for continuous hydrolysis of phosphate or phosphite compounds based on a microreaction system provided by the present invention uses phosphate or phosphite compounds as raw materials, and a continuous microreaction system configured by piping connections, including a micromixer, a microchannel reactor, a backpressure valve, and a gas-liquid separator, to obtain high-purity phosphate or phosphite compounds. Specifically, it includes the following steps (1) to (2): (1) A phosphate or phosphite compound solution and an acid are introduced into a micromixer by pumps, and thoroughly mixed. Then, the mixture is introduced into a microchannel reactor, and a dealcoholization reaction is carried out by hydrolysis to obtain the target product, a phosphate or phosphite compound. (2) The reaction liquid obtained in step (2) is introduced into a gas-liquid separator, which is connected to a back pressure valve and a high-pressure nitrogen source to adjust the pressure during the reaction process. Low-boiling compounds and gases enter an exhaust gas absorption device, and the produced chloromethane by-product is condensed and collected and used as a chemical raw material. The gas is neutralized and absorbed with an alkaline solution until the emission standard is met. The reaction liquid containing phosphoric acid or phosphorous acid compounds is cooled to crystallize, and then filtered and dried to obtain a pure product with a purity of more than 99% and a yield of more than 99% in terms of phosphate ester or phosphite ester.

[0006] In the present invention, the phosphate or phosphite compound is selected from compounds (I) and (II) having the following structures: [ka] In the formula, R 1 is selected from C1-C12 alkyl, C3-C6 cycloalkyl, and R 2 is selected from C1-C12 alkyl and C3-C6 cycloalkyl; X is selected from oxygen, nitrogen and sulfur; and n is selected from 1-12.

[0007] Preferably, in step (1), the acid is one or a combination of two or more selected from the group consisting of 10% aqueous hydrogen chloride solution, 20% aqueous hydrogen chloride solution, 30% aqueous hydrogen chloride solution, 37% aqueous hydrogen chloride solution, methanolic hydrogen chloride solution, 20% aqueous sulfuric acid solution, 30% aqueous sulfuric acid solution, 37% aqueous sulfuric acid solution, 10% aqueous phosphoric acid solution, 20% aqueous phosphoric acid solution, 30% aqueous phosphoric acid solution, and 37% aqueous phosphoric acid solution.

[0008] Preferably, in step (1), the solvent for the phosphate or phosphite compound solution is one or a combination of two or more selected from the group consisting of pentanol, butanol, isobutanol, tert-butanol, propanol, isopropanol, ethanol, methanol, tetrahydrofuran, 2-methyltetrahydrofuran, acetone, butanone, and methyl isobutyl ketone.

[0009] Preferably, in step (1), the amount of the acid used is 1.0-30 equivalents of the phosphate or phosphite compound.

[0010] Preferably, in step (1), the temperature of the reactor is 120-200°C and the reaction time is 5-20 min.

[0011] Preferably, in step (2), the pressure of the back pressure valve is controlled to 10-100 bar, and the solvent used for the crystallization is selected from water, methanol, ethanol, and propanol.

[0012] Preferably, the micromixer is a T-type, Y-type, Z-type, X-type, SK-type, SX-type, SX-type, or M-type; The T-type, Y-type, Z-type, X-type, SK-type, SX-type, and SX-type micro mixers have an inlet and outlet size of 1.0mm-6.0mm, a mixing chamber diameter of 1.0mm-20mm, and a height of 1.0mm-40mm; The M-type micromixer is a tubular microreactor with a specially designed M-shaped mixing element built in. The bellows-shaped (i.e., M-shaped) mixing element is installed inside the pipe, and a reactant inlet and a reactant outlet are installed at both ends of the pipe, respectively. The outer layer of the pipe is a heat flow layer through which heat flows, and a heat flow inlet and a heat flow outlet are installed at both ends of the heat flow layer, respectively (Figure 2). The M-type micromixer has an inner diameter of 0.5-5 mm and a length of 0.1-20 m.

[0013] Preferably, in step (1), the microchannel reactor is a plate-type or tubular microchannel reactor.

[0014] Preferably, the microchannel reactor is a tubular microreactor with an M-shaped pipe built in, and the tubular microreactor is arranged in an S-shape as a whole, with a bellows-shaped (also called M-shaped) pipe inside, and a reactant inlet and a reactant outlet at both ends, respectively. The outside of the pipe is a heat flow mediating layer through which a heat flow passes, and a heat flow inlet and a heat flow outlet are provided at both ends of the heat flow mediating layer, respectively (Figure 3).

[0015] Preferably, in step (1), the microchannel reactor has an inner diameter of 1.0-50 mm and a length of 0.1-4000 m.

[0016] Preferably, the material of the microchannel reactor is one or a combination of two or more selected from polytetrafluoroethylene, polyvinylidene fluoride, stainless steel, Hastelloy, zirconium, tantalum, nickel, and silicon carbide.

[0017] Compared with the prior art, the present invention has the following advantages: (1) The micro-mixer significantly improves the mass transfer effect of the two-phase system, accelerating the reaction rate while reducing the reactor volume. The microchannel reactor has excellent mass transfer, heat transfer, and continuous material mixing enhancement performance, effectively shortening the reaction time, improving reaction efficiency and the flow rate per unit volume of the reactor, making the reaction safer, and significantly reducing the emissions of three wastes (exhaust gas, wastewater, and solid waste) and energy consumption. The time required for the hydrolysis of phosphate and phosphite ester compounds is reduced from 2-3 hours in traditional batch reactions to just a few minutes.

[0018] (2) This method realizes microchannel continuous hydrolysis of phosphate and phosphite compounds, has a high degree of automation, does not require any intermediate treatment, is time- and space-efficient, greatly reduces the number of workers and labor intensity, and significantly reduces production costs.

[0019] (3) This method solves the pollution problem caused by solvent evaporation by reacting in a closed system, making it safe and environmentally friendly, with low production costs, improved profits, and effectively reduced waste.

[0020] (4) Microchannel continuous synthesis of the product was achieved with a conversion rate of over 99%, purity of more than 99%, and total yield of more than 99%.

[0021] (5) By using microchannel reactors, industrial production of the synthesis method of the present invention can be easily realized through multichannel parallel scale-up or size-up strategies. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a flow chart of the reaction process of the present invention. [Figure 2] FIG. 1 is a structural schematic diagram of a tubular microreactor incorporating an M-shaped mixing element. [Figure 3] FIG. 1 is a structural schematic diagram of a tubular microreactor incorporating an M-shaped mixing element.

[0023] Explanation of symbols In Figures 2 and 3, 1 - reactant inlet, 2 - heat exchange fluid inlet, 3 - M-shaped element, 4 - heat exchange fluid outlet, 5 - reactant outlet; 6 - M-shaped element, 7 - heat exchange fluid inlet, 8 - reactant inlet, 9 - reactant outlet, 10 - heat exchange fluid outlet. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will now be further described with reference to examples.

[0025] Example 1 R 1 A solution of dimethyl ester (X = CH3, X = N, n = 1) and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in a T-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphite ester, was 85%.

[0026] Example 2 R 1A solution of dimethyl ester (X = CH3, X = N, n = 1) and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in a Y-shaped micromixer and then introduced into a microchannel reactor at a rate of 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction mixture was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction mixture containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, a pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphite ester, was 86%.

[0027] Example 3 R 1 A dimethyl ester solution of ═CH3, X=N, n=1 and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, a pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphite ester, was 99%.

[0028] Example 4 R 1A diethyl ester solution of ═CH2CH3, X=N, n=1, and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 98%, and the overall yield, calculated as phosphite ester, was 98%.

[0029] Example 5 R 1 A dimethyl ester solution of ═CH3, X=O, n=1 and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction mixture was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction mixture containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, a pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphite ester, was 94%.

[0030] Example 6 R 1A dimethyl ester solution of ═CH3, X=O, n=2 and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphate ester, was 98%.

[0031] Example 7 R 2 A trimethyl ester solution of ═CH3, X=N, n=1 and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphate ester, was 97%.

[0032] Example 8 R 2A triethyl ester solution of ═CH2CH3, X=N, n=1, and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction mixture was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction mixture containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 98%, and the overall yield, calculated as phosphate ester, was 95%.

[0033] Example 9 R 2 A trimethyl ester solution of ═CH3, X=O, n=1 and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphate ester, was 92%.

[0034] Example 10 R 2A trimethyl ester solution of ═CH3, X=N, n=2, and hydrochloric acid (35%, 3.5 eq) were thoroughly mixed in an M-type micromixer and then introduced into a microchannel reactor at 5.6 mL / min. The target product was produced by dealcoholization via hydrolysis at 150 °C for 10 min. The reaction solution was then introduced into a gas-liquid separator. The gas-liquid separator was connected to a backpressure valve (25 bar) and a high-pressure nitrogen source to regulate the pressure throughout the reaction process. Low-boiling compounds and gases were introduced into an exhaust gas absorption unit. The chloromethane by-product was condensed and collected, then reused as a chemical feedstock. The gas was neutralized and absorbed with an alkaline solution until it reached the emission standard. The reaction solution containing the target product was cooled, and 25 mL of methanol was added to crystallize it. After filtration and drying, the pure product was obtained. The purity was 99%, and the overall yield, calculated as phosphate ester, was 97%.

[0035] Although the above embodiments have been described in this specification, they are not intended to limit the scope of protection of the present invention. Therefore, any changes and modifications to the embodiments described in this specification based on the concept of the present invention, or equivalent structure or process conversions made in accordance with the contents of this specification and drawings, or direct or indirect application of the above technical means to other related technologies, are all included in the scope of protection of the present invention.

Claims

1. A method for continuous hydrolysis of a phosphate ester or phosphite ester compound using a phosphate ester or phosphite ester compound as a raw material, in which a high-purity phosphoric acid or phosphorous acid compound is obtained by a continuous micro reaction system configured by piping connections using a micro mixer, a microchannel reactor, a back pressure valve, and a gas-liquid separator, Specifically, the method includes the following steps (1) to (2): (1) A phosphate or phosphite compound solution and an acid are introduced into a micromixer by pumps, and then thoroughly mixed. Then, the mixture is introduced into a microchannel reactor, and a dealcoholization reaction is carried out by hydrolysis to obtain the target product, a phosphate or phosphite compound. (2) The reaction liquid obtained in step (1) is introduced into a gas-liquid separator, and the gas-liquid separator is connected to a back pressure valve and a high-pressure nitrogen source to adjust the pressure during the reaction process. The low-boiling compounds and gas enter an exhaust gas absorption device, and the produced chloromethane by-product is condensed and collected and used as a chemical raw material. The gas is neutralized and absorbed with an alkaline solution until the emission standard is reached. The reaction liquid containing phosphoric acid or phosphorous acid compounds is cooled to crystallize, and the crystallized product is filtered and dried to obtain a pure product, the purity of which is more than 99% and the yield of which is calculated as phosphate or phosphite ester is more than 99%.

2. 2. The method according to claim 1, wherein the phosphate or phosphite compound is selected from compounds (I) and (II) having the following structures: 【Chemistry 1】 (In the formula, R １ is selected from C1-C12 alkyl, C3-C6 cycloalkyl, and R ２ is selected from C1-C12 alkyl and C3-C6 cycloalkyl, X is selected from oxygen, nitrogen, and sulfur, and n is selected from 1 to 12.

3. 2. The method of claim 1, wherein in step (1), the acid is selected from 10% aqueous hydrogen chloride solution, 20% aqueous hydrogen chloride solution, 30% aqueous hydrogen chloride solution, 37% aqueous hydrogen chloride solution, methanolic hydrogen chloride solution, 20% aqueous sulfuric acid solution, 30% aqueous sulfuric acid solution, 37% aqueous sulfuric acid solution, 10% aqueous phosphoric acid solution, 20% aqueous phosphoric acid solution, 30% aqueous phosphoric acid solution, and 37% aqueous phosphoric acid solution.

4. 2. The method of claim 1, wherein in step (1), the solvent for the phosphate or phosphite compound solution is selected from the group consisting of pentanol, butanol, isobutanol, tert-butanol, propanol, isopropanol, ethanol, methanol, tetrahydrofuran, 2-methyltetrahydrofuran, acetone, butanone, and methyl isobutyl ketone.

5. 2. The method of claim 1, wherein in step (1), the amount of the acid used is 1.0-30 equivalents of the phosphate or phosphite compound, the temperature of the reactor is 120-200°C, and the reaction time is 5-20 min.

6. 2. The method of claim 1, wherein in step (2), the pressure of the back pressure valve is controlled to 10-100 bar, and the solvent used for the crystallization is selected from the group consisting of water, methanol, ethanol, and propanol.

7. The micromixer is a T-type, a Y-type, a Z-type, an X-type, an SK-type, an SX-type, an SX-type, or an M-type; The T-type, Y-type, Z-type, X-type, SK-type, SX-type, and SX-type micromixers have inlet and outlet sizes of 1.0 mm-6.0 mm, mixing chamber diameters of 1.0 mm-20 mm, and heights of 1.0 mm-40 mm; The M-type micro mixer is a tubular micro reactor having an M-shaped mixing element built in, and the bellows-shaped, i.e., M-shaped, mixing element is provided inside the pipe, and a reactant inlet and a reactant outlet are provided at both ends of the pipe, respectively. The outer layer of the pipe is a heat flow layer through which a heat flow passes, and a heat flow inlet and a heat flow outlet are provided at both ends of the heat flow layer, respectively. The method according to claim 1, wherein the M-type micromixer has an inner diameter of 0.5-5 mm and a length of 0.1-20 m.

8. The method according to claim 1, wherein the microchannel reactor is a plate-type microchannel reactor or a tubular microchannel reactor.

9. 2. The method according to claim 1, wherein the microchannel reactor is a tubular microreactor having an M-shaped pipe built in, the tubular microreactor being arranged in an S-shape as a whole, a bellows-shaped (also called M-shaped) pipe being provided inside the pipe, a reactant inlet and a reactant outlet being provided at both ends, respectively, a heat flow intervening layer for heat flow to pass outside the pipe, and a heat flow inlet and a heat flow outlet being provided at both ends of the heat flow intervening layer, respectively.

10. The method according to claim 9, wherein the microchannel reactor has an inner diameter of 1.0-50 mm and a length of 0.1-4000 m.

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