Method for continuously preparing alkyl phosphate dialkyl ester by adopting microchannel reactor
By using a microchannel reactor for continuous preparation in the production of dialkyl alkyl phosphate, the problems of long reaction time, high energy consumption and many side reactions in the traditional production process are solved, and the effects of shortening reaction time, reducing energy consumption, improving product yield and purity are achieved.
Patent Information
- Application Number
- CN202510002452.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-04-11
AI Technical Summary
In the production process of traditional dialkyl alkyl phosphate, expensive catalysts are needed, with high reaction temperature, long time, many side reactions, low product yields, resulting in high production costs and poor economic benefits.
The microchannel reactor is used for continuous preparation, and the use of organic solvents is avoided and the generation of oxidation by-products is reduced. Large-scale heating systems are not required. The purification is simplified by underpressure distillation and energy consumption is reduced.
It achieves a significant shortening of the reaction time, reduces energy consumption and production costs, improves the yield and purity of the product, avoids the generation of side reactions, and provides a new idea for industrial production of dialkyl alkyl phosphate.
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Figure CN119798317A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for continuously preparing dialkyl alkyl phosphate by using a microchannel reactor. Background Art
[0002] Alkyl dialkyl phosphates are widely used in flame retardant epoxy resins, unsaturated polyester resins, polyurethane foams and furan resin materials. For example, dimethyl methyl phosphate is widely used as polyurethane foams and polyurethane resins, and can also be used as a key intermediate in the synthesis of organophosphorus pesticides such as glufosinate; diethyl ethyl phosphate is an important raw material for the pharmaceutical industry and flame retardant industry, with the advantages of low viscosity, suitable boiling point, good solubility, and good flame retardant effect; dibutyl butyl phosphate can be used as a heavy metal extractant, gasoline additive and plasticizer. Traditional alkyl dialkyl phosphates are mainly synthesized by Michaelis-Arbuzov rearrangement reaction of trialkyl phosphite under the catalysis of alkylating agents. Such reactions often require the use of expensive catalysts, high reaction temperatures, long reaction times, more side reactions, low product yields, and high production costs. Therefore, the industrial production of alkyl dialkyl phosphates based on such reactions has poor economic benefits and low promotion value. To this end, the present invention proposes a method for continuously preparing alkyl dialkyl phosphates using a microchannel reactor, in order to provide new ideas for the industrial production of alkyl dialkyl phosphates. Summary of the invention
[0003] The purpose of the present invention is to overcome the defects in the prior art and provide a method for continuously preparing alkyl dialkyl phosphate by using a microchannel reactor. The method utilizes the advantages of the microchannel reactor's super heat exchange capacity and short reaction time to solve the problem of long reaction time required in a conventional reactor; avoids the use of organic solvents, and saves materials; the reaction process can effectively avoid contact with oxygen, and reduce the generation of oxidation by-products; does not require the use of a large-scale heating system, the reduced pressure distillation purification step is simple to operate, and the overall reaction energy consumption is low, thereby providing a new idea for the industrial production of alkyl dialkyl phosphate.
[0004] To achieve the above object, the technical solution of the present invention is to design a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor, comprising the following steps:
[0005] S1: uniformly mixing trialkyl phosphite and a catalyst in a certain molar ratio to obtain a reaction raw material mixed solution;
[0006] S2: setting the reaction temperature of the microchannel reactor, and when the temperature of the microchannel reactor rises to the set reaction temperature, continuously adding the reaction raw material mixture prepared in step S1 to the feed port of the microchannel reactor, the reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor to obtain a reaction product mixture, and the reaction product mixture flows out from the discharge port of the microchannel reactor into the collecting tank;
[0007] S3: distilling the reaction product mixture collected in the collecting tank under reduced pressure to obtain dialkyl alkyl phosphate.
[0008] A preferred technical solution is that in the step S1, the catalyst used is alkyl p-toluenesulfonate, and the molar feed ratio of trialkyl phosphite to the catalyst is 1:0.001-0.005.
[0009] A further preferred technical solution is that in the step S1, the trialkyl phosphite used is one of trimethyl phosphite, triethyl phosphite and tributyl phosphite.
[0010] Another preferred technical solution is that in the step S2, a high-pressure constant flow pump is used to continuously add the reaction raw material mixture prepared in step S1 to the feed port of the microchannel reactor at a certain flow rate, the reaction temperature is 100-180°C, the reaction residence time is 50-150s, and the reaction pressure is 0-10bar.
[0011] A further preferred technical solution is that in the step S2, the flow rate at which the reaction raw material mixture is added to the microchannel reactor is 18 to 54 mL / min.
[0012] Another preferred technical solution is that in step S3, the recovered catalyst is directly applied to step S1.
[0013] The advantages and beneficial effects of the present invention are:
[0014] 1. The method of the present invention for continuously preparing dialkyl alkyl phosphate by using a microchannel reactor solves the problem of long reaction time required in conventional reactors by utilizing the advantages of super heat exchange capacity and short reaction time of the microchannel reactor; it does not need to use a large-scale heating system, reduces reaction energy consumption, and provides a new idea for the industrial production of dialkyl alkyl phosphate.
[0015] 2. The method of the present invention for continuously preparing dialkyl alkyl phosphate using a microchannel reactor avoids the use of organic solvents and saves materials; the reaction process can effectively avoid contact with oxygen and reduce the generation of oxidation by-products; the vacuum distillation purification step is simple to operate, further reducing the energy consumption problem caused by separation and purification.
[0016] 3. The method of the present invention for continuously preparing dialkyl alkyl phosphate using a microchannel reactor adopts a continuous flow reaction in the microchannel reactor. The reaction residence time in the microchannel reactor can be accurately controlled by adjusting the flow rate of the reaction raw material mixture. The total reaction time is much shorter than that of the traditional autoclave reaction, thereby improving production efficiency and reducing production costs.
[0017] 4. In the method of the present invention for continuously preparing dialkyl alkyl phosphate using a microchannel reactor, the residual liquid containing the catalyst obtained during the vacuum distillation process can be directly applied to the preparation process of the reaction raw material mixture. It has been verified that the method can be repeatedly applied for more than 30 times while keeping the catalytic effect basically unchanged, thereby increasing the frequency of reusable catalyst and reducing reaction cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 The present invention is a flow chart of a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor. DETAILED DESCRIPTION
[0019] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.
[0020] Example 1
[0021] like Figure 1 As shown, a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor of the present invention is used to prepare dibutyl butyl phosphate, comprising the following steps:
[0022] S1: dissolving a certain amount of butyl p-toluenesulfonate in tributyl phosphite at room temperature to prepare a reaction raw material mixed solution, wherein the molar ratio of butyl p-toluenesulfonate to tributyl phosphite is 0.002:1;
[0023] S2: The microchannel reactor module is heated to 150°C using a refrigeration and heating temperature control system; a high-pressure constant flow pump with precise flow control is used to continuously deliver the reaction raw material mixture to the feed port of the microchannel reactor at a flow rate of 18 mL / min. The reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor. The reaction pressure is 0 to 10 bar. After 130 seconds of reaction, the reaction product mixture flows out from the discharge port of the microchannel reactor into the collection tank;
[0024] S3: Use an oil pump to vacuum distill the reaction product mixture in the collecting tank to obtain colorless oily liquid dibutyl butyl phosphate (molar yield: 94.2%, calculated as tributyl phosphite), GC purity: 98.1%; the recovered liquid containing butyl p-toluenesulfonate is directly applied to step S1.
[0025] Example 2
[0026] like Figure 1 As shown, a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor of the present invention is used to prepare dibutyl butyl phosphate, comprising the following steps:
[0027] T1: the liquid containing butyl p-toluenesulfonate recycled 30 times in step S3 of Example 1 is prepared into a reaction raw material mixed solution with tributyl phosphite at room temperature, and the molar ratio of butyl p-toluenesulfonate to tributyl phosphite is 0.002:1 (based on the initial charging amount of butyl p-toluenesulfonate in Example 1);
[0028] T2: The microchannel reactor module is heated to 150°C using a refrigeration and heating temperature control system; a high-pressure constant flow pump with precise flow control is used to continuously deliver the reaction raw material mixture to the feed port of the microchannel reactor at a flow rate of 28 mL / min. The reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor. The reaction pressure is 0 to 10 bar. After 130 seconds of reaction, the reaction product mixture flows out from the discharge port of the microchannel reactor into the collection tank;
[0029] T3: The reaction product mixture in the collecting tank was subjected to vacuum distillation using an oil pump to obtain colorless oily liquid dibutyl butyl phosphate (molar yield: 96.5%, calculated as tributyl phosphite) with a GC purity of 98.5%.
[0030] Example 3
[0031] like Figure 1 As shown, a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor of the present invention is used to prepare dimethyl methyl phosphate, comprising the following steps:
[0032] W1: a certain amount of methyl p-toluenesulfonate is dissolved in trimethyl phosphite at room temperature to prepare a reaction raw material mixed solution, wherein the molar ratio of methyl p-toluenesulfonate to trimethyl phosphite is 0.001:1;
[0033] W2: The microchannel reactor module is heated to 180°C using a refrigeration and heating temperature control system; a high-pressure constant flow pump with precise flow control is used to continuously deliver the reaction raw material mixture to the feed port of the microchannel reactor at a flow rate of 42 mL / min. The reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor. The reaction pressure is 0 to 10 bar. After 150 seconds of reaction, the reaction product mixture flows out from the discharge port of the microchannel reactor into the collection tank;
[0034] W3: Use an oil pump to vacuum distill the reaction product mixture in the collecting tank to obtain colorless oily liquid dimethyl methyl phosphate (molar yield: 93.5%, calculated as trimethyl phosphite), GC purity: 98.8%; the recovered liquid containing methyl p-toluenesulfonate is directly applied to step W1.
[0035] Example 4
[0036] like Figure 1 As shown, a method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor of the present invention is used to prepare diethyl methyl phosphate, comprising the following steps:
[0037] Z1: dissolving a certain amount of ethyl p-toluenesulfonate in triethyl phosphite at room temperature to prepare a reaction raw material mixed solution, wherein the molar ratio of ethyl p-toluenesulfonate to triethyl phosphite is 0.005:1;
[0038] Z2: The microchannel reactor module is heated to 100°C using a refrigeration and heating temperature control system; a high-pressure constant flow pump with precise flow control is used to continuously deliver the reaction raw material mixture to the feed port of the microchannel reactor at a flow rate of 54 mL / min. The reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor. After 50 seconds of reaction, the reaction pressure is 0 to 10 bar, and the reaction product mixture flows out from the discharge port of the microchannel reactor into the collection tank;
[0039] Z3: Use an oil pump to vacuum distill the reaction product mixture in the collecting tank to obtain colorless oily liquid diethyl methyl phosphate (molar yield: 95.8%, calculated as triethyl phosphite), GC purity: 98.4%; the recovered liquid containing ethyl p-toluenesulfonate is directly applied to step Z1.
[0040] Embodiments 1 to 4 adopt the method of the present invention for continuously preparing dialkyl alkyl phosphate using a microchannel reactor, using trialkyl phosphite as a starting material and alkyl p-toluenesulfonate as a catalyst, without using an organic solvent, and carrying out a rearrangement reaction in a microchannel reactor. The reaction product mixed solution is subjected to conventional reduced pressure distillation treatment to obtain the target product; and the molar yield of the target product is above 93%, and its purity is as high as above 98.0%; the use of organic solvents is avoided, saving materials; the reaction is carried out in a continuous flow manner, thereby improving production efficiency and reducing production costs; the residual liquid containing the catalyst obtained during the reduced pressure distillation process can be directly applied to the preparation process of the reaction raw material mixed solution, and it has been verified that it can be repeatedly applied for more than 30 times while keeping the catalytic effect basically unchanged, thereby increasing the frequency of reusability of the catalyst, reducing the reaction cost, and achieving the purpose of the invention.
[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor, characterized in that: The steps are as follows: S1: uniformly mixing trialkyl phosphite and a catalyst in a certain molar ratio to obtain a reaction raw material mixed solution; S2: setting the reaction temperature of the microchannel reactor, and when the temperature of the microchannel reactor rises to the set reaction temperature, continuously adding the reaction raw material mixture prepared in step S1 to the feed port of the microchannel reactor, the reaction raw material mixture is sequentially preheated and rearranged in the liquid phase reaction channel of the microchannel reactor to obtain a reaction product mixture, and the reaction product mixture flows out from the discharge port of the microchannel reactor into the collecting tank; S3: distilling the reaction product mixture collected in the collecting tank under reduced pressure to obtain dialkyl alkyl phosphate.
2. The method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor as claimed in claim 1, characterized in that: In the step S1, the catalyst used is alkyl p-toluenesulfonate, and the molar feed ratio of trialkyl phosphite to the catalyst is 1:0.001-0.
005.
3. The method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor as claimed in claim 2, characterized in that: In the step S1, the trialkyl phosphite used is one of trimethyl phosphite, triethyl phosphite and tributyl phosphite.
4. The method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor as claimed in claim 1, characterized in that: In the step S2, a high-pressure constant flow pump is used to continuously add the reaction raw material mixture prepared in step S1 to the feed port of the microchannel reactor at a certain flow rate, the reaction temperature is 100-180°C, the reaction residence time is 50-150s, and the reaction pressure is 0-10bar.
5. The method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor as claimed in claim 4, characterized in that: In the step S2, the flow rate of the reaction raw material mixture added to the microchannel reactor is 18-54 mL / min.
6. The method for continuously preparing dialkyl alkyl phosphate using a microchannel reactor as claimed in claim 1, characterized in that: In the step S3, the recovered catalyst is directly applied to the step S1.