A method for preparing phosphorous acid using fatty acid chloride as byproduct

Abstract

The present invention belongs to the technical field of chemical production, and specifically relates to a method for preparing phosphorous acid from fatty acyl chloride byproducts. The present invention injects the fatty acyl chloride byproduct into water, the initial temperature of the water is ≤20°C, the temperature of the injection process is <60°C, and a reaction liquid is obtained after the injection is completed; the reaction liquid is subjected to a heat preservation reaction to obtain a heat preservation reaction liquid; the heat preservation reaction liquid is allowed to stand for stratification to obtain a lower layer of clear liquid; the lower layer of clear liquid is subjected to a decolorization treatment to obtain a phosphorous acid solution. In summary, on the one hand, the present invention recovers phosphorous acid from the fatty acyl chloride byproduct, reduces the production cost of fatty acyl chloride, improves the competitiveness of the product, and generates huge economic benefits; on the other hand, it solves the problem that the fatty acyl chloride byproduct cannot be utilized, greatly reduces liquid waste, and recycles phosphorous acid in the acyl chloride byproduct. Finally, the method provided by the present invention has mild reaction conditions, a simple process, and is suitable for wide industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and in particular relates to a method for preparing phosphorous acid as a by-product of fatty acyl chloride. Background Art

[0002] Fatty acyl chloride is an important chemical raw material and is required in the synthesis of alkyl ketene dimer, organic peroxide, surfactant, pharmaceutical intermediate, etc.

[0003] At present, fatty acid chloride can be obtained by reacting fatty acid with an acyl chlorination agent. As for the acyl chlorination agent, for example, phosphorus trichloride is used. The method of preparing fatty acid chloride using phosphorus trichloride as the acyl chlorination agent has the advantage of simple production. The method uses phosphorus trichloride as the acyl chlorination agent, and obtains fatty acid chloride and by-products after chlorination and separation.

[0004] The above production process will produce a large amount of phosphorus-containing fatty acyl chloride by-products, which greatly increases the production cost of fatty acyl chloride, occupies a large amount of storage space, and causes great safety hazards. The traditional method is to directly treat it as hazardous waste.

[0005] Phosphorous acid, a by-product of fatty acyl chloride, is an important chemical product. It can be used as a plasticizer and stabilizer, or as a raw material for agricultural products. It can also be used in the manufacture of synthetic fibers and phosphites. The market demand is huge.

[0006] The related art discloses a method for preparing phosphorous acid by hydrolyzing the byproduct of pivaloyl chloride, but the method needs to be carried out at a relatively high temperature (eg, 60 to 120° C.), and the reaction conditions are harsh and unsuitable for industrial application. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing phosphorous acid from fatty acyl chloride by-products. The present invention uses fatty acyl chloride by-products as raw materials to prepare high-purity phosphorous acid, reduces the production cost of fatty acyl chloride by-products, generates huge economic benefits, and solves the problem that fatty acyl chloride by-products cannot be utilized, greatly reduces liquid waste, and has mild reaction conditions and is suitable for industrial applications.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] The present invention provides a method for preparing phosphorous acid as a by-product of fatty acyl chloride, comprising the following steps:

[0010] Injecting the fatty acyl chloride byproduct into water, wherein the initial temperature of the water is ≤20°C, the temperature during the injection process is <60°C, and a reaction solution is obtained after the injection is completed;

[0011] The reaction solution is subjected to a heat preservation reaction to obtain a heat preservation reaction solution;

[0012] The insulated reaction solution is allowed to stand for stratification to obtain a lower clear liquid;

[0013] The lower clear liquid is decolorized to obtain a phosphorous acid solution.

[0014] Preferably, the initial temperature of the water is 10-20°C.

[0015] Preferably, the fatty acyl chloride is a fatty acyl chloride having carbon atoms greater than or equal to 8; the mass ratio of the fatty acyl chloride by-product to the water is (3-5):1.

[0016] Preferably, the fatty acid chloride by-product includes one or more of lauroyl chloride by-product, myristoyl chloride by-product, stearoyl chloride by-product, neodecanoyl chloride by-product, isononanoyl chloride by-product and isooctanoyl chloride by-product.

[0017] Preferably, the injection is performed by dripping, and the speed of the dripping is based on the temperature of the injection process being less than 60°C.

[0018] Preferably, the insulation reaction time is 1 to 2 hours.

[0019] Preferably, the standing time is 12 to 15 hours.

[0020] Preferably, the decolorizing agent used in the decolorizing treatment is activated carbon;

[0021] The decolorization treatment is performed 2 to 3 times, and the mass of the decolorizer in each decolorization treatment accounts for 1 to 2% of the mass of the lower clear liquid.

[0022] Preferably, the mass percentage of the phosphorous acid solution is 60-90%.

[0023] Preferably, after obtaining the phosphorous acid solution, the method further comprises: removing the solvent from the phosphorous acid solution to obtain phosphorous acid; the purity of the phosphorous acid is ≥98%.

[0024] The present invention provides a method for preparing phosphorous acid from fatty acyl chloride byproducts, comprising the following steps: injecting fatty acyl chloride byproducts into water, wherein the initial temperature of the water is ≤20°C, the temperature of the injection process is <60°C, and a reaction liquid is obtained after the injection is completed; the reaction liquid is subjected to a heat preservation reaction to obtain a heat preservation reaction liquid; the heat preservation reaction liquid is allowed to stand and stratify to obtain a lower layer of clear liquid; the lower layer of clear liquid is subjected to a decolorization treatment to obtain the phosphorous acid solution. The present invention achieves temperature control of the hydrolysis reaction process of the fatty acyl chloride byproducts by injecting the fatty acyl chloride byproducts into water to cause a hydrolysis reaction, while controlling the initial temperature of the water and the temperature of the injection process, thereby enabling the fatty acyl chloride byproducts to be hydrolyzed as much as possible to obtain a phosphorous acid product, while avoiding the oxidation of phosphorous acid to orthophosphoric acid, and finally obtaining high-purity phosphorous acid. Compared with the prior art, the present invention has the following technical advantages:

[0025] With fatty acyl chloride by-products as raw materials, the fatty acyl chloride by-products are converted to prepare high-purity phosphorous acid. By controlling the method of adding the raw materials, high-purity preparation of phosphorous acid can be achieved under milder conditions, and the fatty acyl chloride by-product waste is converted into phosphorous acid with high economic value, so that the fatty acyl chloride by-products are no longer treated as hazardous waste, and the resource utilization of phosphorous acid in the fatty acyl chloride by-products is fully realized.

[0026] In summary, the present invention, on the one hand, reduces the production cost of fatty acyl chloride, improves the competitiveness of the product, and generates huge economic benefits; on the other hand, it solves the problem that the fatty acyl chloride by-product cannot be utilized, greatly reduces liquid waste, and recycles the phosphorous acid in the fatty acyl chloride by-product.

[0027] Finally, the method provided by the present invention has mild reaction conditions, simple process and is suitable for wide industrial application.

[0028] Further, in the present invention, the fatty acyl chloride is a fatty acyl chloride having a carbon number greater than or equal to 8, and the fatty acyl chloride specifically includes one or more of lauroyl chloride byproduct, myristoyl chloride byproduct, stearoyl chloride byproduct, neodecanoyl chloride byproduct, isononanoyl chloride byproduct and isooctanoyl chloride byproduct. The method provided by the present invention is more suitable for preparing phosphorous acid from long-chain acyl chloride byproducts, and the reaction conditions are mild. DETAILED DESCRIPTION

[0029] The present invention provides a method for preparing phosphorous acid as a by-product of fatty acyl chloride, comprising the following steps:

[0030] Injecting the fatty acyl chloride byproduct into water, wherein the initial temperature of the water is ≤20°C, the temperature during the injection process is <60°C, and a reaction solution is obtained after the injection is completed;

[0031] The reaction solution is subjected to a heat preservation reaction to obtain a heat preservation reaction solution;

[0032] The insulated reaction solution is allowed to stand for stratification to obtain a lower clear liquid;

[0033] The lower clear liquid is decolorized to obtain a phosphorous acid solution.

[0034] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0035] The present invention injects the fatty acyl chloride byproduct into water, the initial temperature of the water is ≤20°C, the temperature of the injection process is <60°C, and a reaction solution is obtained after the injection is completed. In the present invention, the fatty acyl chloride byproduct is produced in the process of preparing fatty acyl chloride using fatty acids and phosphorus trichloride as raw materials. Specifically, after the reaction of fatty acids and phosphorus trichloride is completed, the layers are allowed to stand and separate, the upper layer is the crude fatty acyl chloride, and the lower layer is the fatty acyl chloride byproduct. The main components of the fatty acyl chloride byproduct are phosphorous acid, fatty acids, fatty acyl chloride and phosphorus trichloride and phosphorus trichloride-related byproducts, wherein the phosphorus trichloride-related byproducts include the following substances:

[0036]

[0037] In the present invention, the fatty acid chloride by-product preferably includes one or more of lauroyl chloride by-product, myristoyl chloride by-product, stearoyl chloride by-product, neodecanoyl chloride by-product, isononanoyl chloride by-product and isooctanoyl chloride by-product.

[0038] In the present invention, the water is preferably deionized water. The initial temperature of the water is preferably 10-20°C. The present invention preferably controls the initial temperature of the water to ensure that the temperature of the injection process is less than 60°C, that is, the present invention controls the initial temperature of the water to avoid the injection temperature exceeding 60°C as much as possible.

[0039] In the present invention, the temperature of the injection process is less than 60°C, preferably 30-55°C, more preferably 30-50°C, and further preferably 30-45°C.

[0040] In the present invention, the mass ratio of the fatty acyl chloride byproduct to the water is preferably (3-5):1, more preferably (4-5):1. The injection is preferably dripping, and the dripping speed is preferably based on the temperature of the injection process <60°C. The present invention can ensure that the fatty acyl chloride byproduct is completely hydrolyzed by controlling the mass ratio of the fatty acyl chloride byproduct to the water.

[0041] In the present invention, during the injection process and the heat preservation reaction process, the reaction principle of the hydrolysis reaction of the fatty acyl chloride to obtain phosphorous acid is:

[0042]

[0043] After obtaining the reaction liquid, the present invention performs a heat preservation reaction on the reaction liquid to obtain a heat preservation reaction liquid. In the present invention, the heat preservation reaction time is preferably 1 to 2 hours, and in the embodiment it can be 1 hour. The heat preservation reaction is carried out under stirring. The temperature of the heat preservation reaction is preferably 30 to 55°C, more preferably 30 to 50°C, and further preferably 30 to 45°C. The present invention can further completely hydrolyze the fatty acyl chloride by-product by performing a heat preservation reaction after injection.

[0044] After obtaining the heat preservation reaction liquid, the present invention allows the heat preservation reaction liquid to stand for stratification to obtain a lower layer of clear liquid. In the present invention, the standing time is 12 to 15 hours, and in the embodiment, it can be 12 hours.

[0045] After obtaining the lower clear liquid, the present invention decolorizes the lower clear liquid to obtain the phosphorous acid solution. In the present invention, the decolorizing agent used in the decolorizing treatment is preferably activated carbon. The number of decolorizing treatments is preferably 2 to 3 times, and the mass of the decolorizing agent in each decolorizing treatment is preferably 1 to 2% of the mass of the lower clear liquid, and can be 1% in the embodiment. After the decolorizing treatment, the present invention preferably obtains the phosphorous acid solution by solid-liquid separation. The solid-liquid separation is preferably filtration.

[0046] In the present invention, the mass percentage of the phosphorous acid solution is preferably 60 to 90%.

[0047] In the present invention, after obtaining the phosphorous acid solution, the present invention preferably further comprises: removing the solvent from the phosphorous acid solution to obtain phosphorous acid. The specific implementation of the solvent removal is preferably evaporation. The present invention removes the solvent in the phosphorous acid solution by evaporation, and the present invention has no special requirements for the specific implementation process of the evaporation. The purity of the phosphorous acid is preferably ≥98%, more preferably ≥99%, and further preferably 99.4-99.5%.

[0048] The invention greatly reduces liquid waste, lowers the production cost of fatty acid chloride, and generates huge economic benefits.

[0049] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0050] The phosphorous acid products prepared in the following examples were analyzed using the industrial phosphorous acid standard method, standard number HG / T 2520-2023.

[0051] Example 1

[0052] Put 70.3g of deionized water into a 500mL four-necked flask, and then add 320.6g of fatty acyl chloride byproduct (lauroyl chloride byproduct) into a constant pressure dropping funnel. First cool the deionized water to 15°C, and then slowly add the fatty acyl chloride byproduct. During the addition of the fatty acyl chloride byproduct, the temperature is maintained at 45±5°C. The temperature after the addition is completed is 45°C, and then keep warm for 1h. After the reaction is completed, pour it into a separatory funnel and let it stand for 12h.

[0053] After standing, the lower clear liquid was taken out and activated carbon was added for decolorization 3 times, with the mass of activated carbon used for decolorization accounting for 1% of the mass of the lower clear liquid each time, and 324.7g of pure phosphorous acid solution was obtained, and the mass percentage of phosphorous acid solution was 90%.

[0054] The phosphorous acid solution is evaporated to obtain phosphorous acid, wherein the phosphorous acid has a purity of 99.5 wt %.

[0055] Purity test results of phosphorous acid side: fatty acid 0.08wt%, Fe 4.49ppm, PO4 3- 0.33wt%SO4 2- 0.004wt%Cl - 0.085wt%.

[0056] Example 2

[0057] Put 6.7kg of deionized water into a 50L kettle, and then add 30.7kg of fatty acid chloride byproduct (myristic acid chloride byproduct) into the overhead tank. First cool the deionized water to 15℃, and then slowly add the fatty acid chloride byproduct. During the addition of the fatty acid chloride byproduct, the temperature is maintained at 45±5℃. The temperature after the addition is completed is 45℃, and then keep warm at 45℃ for 1h. After the reaction is completed, stop stirring and let it stand in the kettle for 12h.

[0058] After standing, take out the lower clear liquid, add activated carbon for decolorization 3 times, the mass of activated carbon used for decolorization each time accounts for 1% of the mass of the lower clear liquid, and 31.7 kg of pure phosphorous acid solution can be obtained.

[0059] The phosphorous acid solution is evaporated to obtain phosphorous acid, wherein the phosphorous acid purity is 99.4 wt %.

[0060] Purity test results of phosphorous acid side: fatty acid 0.08wt%, Fe 4.05ppm, PO4 3- 0.38wt%SO4 2- 0.005wt%Cl - 0.086wt%.

[0061] Comparative Example 1

[0062] Put 6.7kg of deionized water into a 50L kettle, and then add 30.7kg of fatty acyl chloride byproduct (lauroyl chloride byproduct) into the overhead tank. First cool the deionized water to 15°C, and then slowly add the fatty acyl chloride byproduct. During the addition of the fatty acyl chloride byproduct, the temperature is maintained at 80°C. After the addition is completed, keep the temperature at 80°C for 1 hour. After the reaction is completed, stop stirring and let it stand in the kettle for 12 hours.

[0063] After standing, the lower clear liquid was taken out and activated carbon was added for decolorization 3 times, with the mass of activated carbon used for decolorization accounting for 1% of the mass of the lower clear liquid, and 30.9 kg of pure phosphorous acid solution was obtained.

[0064] The phosphorous acid solution is dried to obtain phosphorous acid, wherein the phosphorous acid has a purity of 96.7 wt %.

[0065] Purity test results of phosphorous acid side: fatty acid 0.08wt%, Fe 4.05ppm, PO4 3- 3.12wt%SO4 2- 0.005wt%Cl - 0.086wt%.

[0066] Comparative Example 2

[0067] Put 6.7kg of deionized water into a 50L kettle, and then add 30.7kg of acyl chloride byproduct (myristic acid chloride byproduct) into the overhead tank. First cool the deionized water to 15℃, and then slowly add the fatty acyl chloride byproduct. During the addition of the acyl chloride byproduct, the temperature is maintained at 45±5℃. The temperature after the addition is completed is 45℃, and then keep warm at 45℃ for 1h. After the reaction is completed, stop stirring and let it stand in the kettle for 12h.

[0068] After standing, the lower clear liquid was taken out to obtain 32.7 kg of phosphorous acid solution.

[0069] The phosphorous acid solution is dried to obtain phosphorous acid, wherein the phosphorous acid has a purity of 97.98 wt%.

[0070] The purity test results of phosphorous acid side: fatty acid 0.96wt%, Fe 5.09ppm, PO4 3- 0.84wt%SO4 2- 0.09wt%Cl - 0.13wt%.

[0071] Since the comparative example was not subjected to decolorization treatment, the foam phenomenon was serious after the product was shaken and did not disappear for a long time.

[0072] It can be seen from the above embodiments that the present invention uses fatty acyl chloride by-products as raw materials, converts fatty acyl chloride by-products to prepare high-purity phosphorous acid, and converts fatty acyl chloride by-product waste into phosphorous acid with high economic value, so that fatty acyl chloride by-products are no longer treated as hazardous waste, and fully realizes the resource utilization of phosphorous acid in fatty acyl chloride by-products. In summary, on the one hand, the present invention reduces the production cost of fatty acyl chloride, improves the competitiveness of products, and generates huge economic benefits; on the other hand, it solves the problem that fatty acyl chloride by-products cannot be utilized, greatly reduces liquid waste, and recycles phosphorous acid in fatty acyl chloride by-products. Finally, the method provided by the present invention has mild reaction conditions, simple process, and is suitable for wide industrial application.

[0073] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing phosphorous acid from fatty acyl chloride as a by-product, characterized in that: The following steps are involved: Injecting the fatty acyl chloride byproduct into water, wherein the initial temperature of the water is ≤20°C, the temperature during the injection process is <60°C, and a reaction solution is obtained after the injection is completed; The reaction solution is subjected to a heat preservation reaction to obtain a heat preservation reaction solution; The insulated reaction solution is allowed to stand for stratification to obtain a lower clear liquid; The lower clear liquid is decolorized to obtain a phosphorous acid solution.

2. The method according to claim 1, characterized in that The initial temperature of the water is 10-20°C.

3. The method according to claim 1 or 2, characterized in that: The fatty acyl chloride is a fatty acyl chloride having carbon atoms greater than or equal to 8; the mass ratio of the fatty acyl chloride byproduct to the water is (3-5):

1.

4. The method according to claim 1, characterized in that: The fatty acid chloride by-products include one or more of lauroyl chloride by-products, myristoyl chloride by-products, stearoyl chloride by-products, neodecanoyl chloride by-products, isononanoyl chloride by-products and isooctanoyl chloride by-products.

5. The method according to claim 1, characterized in that The injection is performed by dropwise addition, and the speed of the dropwise addition is based on the temperature of the injection process being less than 60°C.

6. The method according to claim 1, characterized in that The insulation reaction time is 1 to 2 hours.

7. The method according to claim 1, characterized in that The standing time is 12 to 15 hours.

8. The method according to claim 1, characterized in that The decolorizing agent used in the decolorizing treatment is activated carbon; The decolorization treatment is performed 2 to 3 times, and the mass of the decolorizer in each decolorization treatment accounts for 1 to 2% of the mass of the lower clear liquid.

9. The method according to claim 1, characterized in that: The mass percentage of the phosphorous acid solution is 60-90%.

10. The method according to claim 1 or 9, characterized in that: After obtaining the phosphorous acid solution, the method further comprises: removing the solvent from the phosphorous acid solution to obtain phosphorous acid; the purity of the phosphorous acid is ≥98%.

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