Process for the preparation of ionic energetic compounds by reaction-filter coupling

Abstract

This invention belongs to the field of compound preparation and purification technology, and particularly relates to a novel method for preparing ionic energetic compounds using a reaction-filtration coupling method. The method includes the following effective steps: adding raw materials to a reaction vessel to prepare ionic energetic compounds and impurity molecules, obtaining a reaction solution; selecting a reaction filtration membrane and installing it into a membrane filtration system; using a feed pump to pump the reaction solution into the membrane filtration system, controlling the material input using a material pump, and adjusting the filtration pressure of the membrane filtration system using a material pump and a pressure regulating valve, while simultaneously controlling the filtration temperature; returning the permeate produced after passing through the membrane filtration system to the reaction vessel for cyclic filtration; increasing the filtration pressure to concentrate the ionic energetic compound solution to obtain a high-concentration solution. This invention completes purification and concentration simultaneously with the synthesis of ionic energetic compounds, resulting in high purity, high yield, continuous production, and suitability for large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of compound preparation and separation and purification technology, and particularly relates to a method for preparing ionic energetic compounds by reaction-filtration coupling. Background Technology

[0002] Ionic energetic compounds possess advantages such as high energy per unit volume, good solubility, good stability, and low characteristic signal, leading to their widespread application in the propellant field. Currently, ionic energetic compound oxidants that are extensively researched and widely used both domestically and internationally include hydrazine nitrate and ammonium dinitrate.

[0003] Currently, in existing technologies, the synthesis of ionic energetic compounds easily generates a large amount of inorganic salt byproducts, and the separation and purification process requires the use of large amounts of organic solvents such as ethanol, methanol, and ethyl acetate. Furthermore, purification methods using adsorbents are time-consuming and labor-intensive, generating significant amounts of solid waste. For example, the synthesis of hydrazine nitrate mainly involves the reaction of nitric acid and hydrazine, a strong acid-strong base reaction. This reaction is violent, difficult to control, and challenging for large-scale single-batch production. Moreover, strong acids and bases place high demands on equipment, requiring strict temperature control and resulting in high energy consumption. The mixed acid method for preparing dinitramide ammonium generates a large amount of inorganic salt byproducts. The separation and purification of dinitramide ammonium can be achieved by utilizing the difference in solubility of organic solvents for dinitramide ammonium and inorganic salts.

[0004] Furthermore, in existing general production processes, the target molecule is usually synthesized first using a certain method, and then further separated and purified. The separated impurity molecules cannot be used for further reactions, which wastes a lot of time, manpower, and resources, and makes it impossible to achieve continuous production.

[0005] Therefore, developing safe, green, high-purity, efficient, low-cost, versatile, and easily industrialized purification processes is key to solving the application problems of ionic energetic compounds. Among existing technologies, membrane filtration methods are characterized by low production costs, no additional substances added, no phase change during filtration, safety, simple operation, high-concentration capability, and ease of industrial production, making them promising for the separation and purification of ionic energetic compounds. To this end, we provide a reaction-filtration coupling method for preparing ionic energetic compounds. This method simultaneously purifies and concentrates the ionic energetic compound, with impurities refluxed back into the reaction vessel for further reaction. There is no loss of raw materials, and the equipment is compact, capable of producing high-purity, high-yield ionic energetic compounds. The production process is continuous and suitable for large-scale preparation. Summary of the Invention

[0006] This invention addresses the technical problems existing in the preparation, synthesis, separation, and purification of ionic energetic compounds mentioned above, and proposes a reaction-filtration coupling method for preparing ionic energetic compounds that is rationally designed, simple in structure, easy to process, and can realize small-scale, continuous, and large-scale preparation of high-purity, high-yield ionic energetic compounds.

[0007] To achieve the above objectives, the present invention employs a method for preparing ionic energetic compounds via a reaction-filtration coupling process, comprising the following effective steps:

[0008] a. First, the raw materials are added to the reaction vessel to prepare ionic energetic compounds and impurity molecules, and a reaction solution is obtained;

[0009] b. Select a reactive filtration membrane and install it into the membrane filtration system;

[0010] c. Use a feed pump to pump the reaction solution into the membrane filtration system, use a material pump to control the input of materials, and use the material pump and pressure regulating valve to adjust the filtration pressure of the membrane filtration system, while controlling the filtration temperature and using a temperature sensor for real-time monitoring.

[0011] d. The permeate produced after passing through the membrane filtration system is returned to the reaction vessel for circulation filtration until a high-purity ionic energetic compound solution is obtained.

[0012] e. Increase the filtration pressure to concentrate the ionic energetic compound solution to obtain a high-concentration solution.

[0013] Preferably, in step a, the reaction vessel selected includes reaction kettles, polymerization kettles, storage tanks, and stirring tanks that facilitate chemical reactions. The reaction vessel needs to be kept within safe reaction conditions, that is, the reaction temperature is below the safe temperature. For heat-generating reactions, temperature can be controlled by diluting the feed liquid and cooling down to ensure the safety of the production reaction process.

[0014] Preferably, in step b, the membrane filtration system includes microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, while the reaction filtration membrane includes, but is not limited to, ceramic membranes, hollow fiber membranes, and organic spiral wound membranes. Specifically, the selected membrane filtration system and reaction filtration membrane need to have high separation efficiency for ionic energetic compounds and impurity molecules. The specifications of the selected reaction filtration membrane include: nanofiltration membranes including, but not limited to, 100D, 200D, 500D, and 800D; ultrafiltration membranes including, but not limited to, 1000D, 2000D, 3000D, and 800KD; and microfiltration membranes including, but not limited to, 0.1 μm, 0.2 μm, 0.3 μm, and 0.45 μm, ensuring a high rejection rate for ionic energetic compounds.

[0015] Preferably, in step c, the filtration pressure adjusted by the material pump and pressure regulating valve for the membrane filtration system is: microfiltration < 0.4 MPa, ultrafiltration < 0.7 MPa, nanofiltration < 4 MPa, and reverse osmosis < 4 MPa. Specifically, during the process of controlling the system filtration pressure using the material pump and pressure regulating valve, and in conjunction with the filtration flux and energy consumption, the filtration pressure for different membrane filtration systems is: microfiltration < 0.4 MPa, ultrafiltration < 0.7 MPa, and nanofiltration and reverse osmosis 1.5~3 MPa.

[0016] Preferably, in step c, the filtration temperature is controlled by a system cooling device, and the controlled filtration temperature range is 4-55℃. Furthermore, considering the actual production situation and usage requirements, the preferred filtration temperature is 20-35℃.

[0017] Preferably, in step d, the impurity molecules refluxed to the reaction vessel react further with the added raw materials to synthesize ionic energetic compounds, thereby improving their yield and productivity. Of course, in this process, the raw materials need to be provided in a certain molar ratio according to the reaction equation.

[0018] Preferably, in step e, the range of filtration pressure adjusted and increased in the membrane filtration system is: microfiltration < 0.4 MPa, ultrafiltration < 0.7 MPa, nanofiltration < 4 MPa, and reverse osmosis < 15 MPa. Specifically, by utilizing the high rejection rate of ionic energetic compounds by the reactive filtration membrane, the concentration of ionic energetic compounds is achieved by increasing the filtration pressure. Considering energy consumption, yield, and filtration flux, the preferred values ​​for filtration pressure in different membrane filtration systems are: microfiltration preferably 0.3~0.4 MPa, ultrafiltration preferably 0.5~0.7 MPa, nanofiltration preferably 3-4 MPa, and reverse osmosis 5-7 MPa.

[0019] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0020] This invention provides a reaction-filtration coupling method for preparing ionic energetic compounds. This method allows for simultaneous synthesis, separation, and purification, i.e., the reaction-filtration coupling method. While synthesizing the ionic energetic compound, the reaction solution is purified and concentrated to prepare a high-purity, high-yield ionic energetic compound. It features small-scale, continuous, and large-scale preparation capabilities, and allows impurity molecules to be refluxed back to the reaction vessel for further reaction with the reaction solution. It also features low cost, and the continuous production process is, to a certain extent, environmentally friendly, versatile, and efficient, fully meeting production and usage requirements. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the structure of a method for preparing ionic energetic compounds using a reaction-filtration coupling method. Detailed Implementation

[0023] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0024] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0025] Example 1: This example provides a method for preparing ionic energetic compounds using a reaction-filtration coupling method.

[0026] Using hydrazine nitrate as the target molecule, Figure 1 The reaction filtration principle shown is used for the synthesis, purification, and concentration of hydrazine nitrate;

[0027] First, hydrazine nitrate was prepared by direct reaction of concentrated nitric acid and hydrazine hydrate in an aqueous phase. Specifically, 105 mL of concentrated nitric acid was diluted in 400 mL of pure water to obtain a dilute nitric acid solution; 126 mL of hydrazine hydrate was diluted in 100 mL of pure water to obtain a dilute hydrazine hydrate solution; under cooling conditions, the dilute hydrazine hydrate solution was slowly added to the dilute nitric acid solution in a reaction vessel, and the mixture was stirred while controlling the reaction temperature to be below 20°C to obtain a hydrazine nitrate reaction solution.

[0028] A polyamide reverse osmosis membrane is installed inside the membrane housing of the membrane filtration system. The feed pump pumps the hydrazine nitrate reaction solution into the filtration system. The material pump is turned on, and the filtration pressure is controlled at 1.5 MPa and the filtration temperature at 20°C. The filtration is circulated. The permeate is returned to the reactor for further reaction. By continuously adding dilute nitric acid solution and dilute hydrazine hydrate solution, hydrazine nitrate is prepared continuously and on a large scale with a yield of over 99% and a purity of over 99%.

[0029] Example 2: This example provides a method for preparing ionic energetic compounds using a reaction-filtration coupling method.

[0030] Using hydrazine nitrate as the target molecule, Figure 1 The filtration principle shown is used for the synthesis, purification, and concentration of hydrazine nitrate;

[0031] First, hydrazine nitrate was prepared by direct reaction of concentrated nitric acid and hydrazine hydrate in an aqueous phase. Specifically, 105 mL of concentrated nitric acid was diluted in 400 mL of pure water to obtain a dilute nitric acid solution; 157.5 mL of hydrazine hydrate was diluted in 100 mL of pure water to obtain a dilute hydrazine hydrate solution; under cooling conditions, the dilute hydrazine hydrate solution was slowly added to the dilute nitric acid solution in a reactor, stirred, and the reaction temperature was controlled below 20°C to obtain a hydrazine nitrate reaction solution.

[0032] A polyamide reverse osmosis membrane is installed inside the membrane housing of the membrane filtration system. The feed pump pumps the hydrazine nitrate reaction solution into the filtration system. The material pump is turned on, and the filtration pressure is controlled at 1.5 MPa and the filtration temperature at 20°C to achieve circulating filtration. The permeate is returned to the reaction vessel for further reaction. By continuously adding raw materials, hydrazine nitrate can be prepared continuously and on a large scale with a yield of over 99% and a purity of over 99%.

[0033] Example 3: This example provides a method for preparing ionic energetic compounds using a reaction-filtration coupling method.

[0034] Using hydrazine nitrate as the target molecule, Figure 1 The filtration principle shown is used for the synthesis, purification, and concentration of hydrazine nitrate;

[0035] First, hydrazine nitrate was prepared by direct reaction of concentrated nitric acid and hydrazine hydrate in an aqueous phase. Specifically, 105 mL of concentrated nitric acid was diluted in 400 mL of pure water to obtain a dilute nitric acid solution; 126 mL of hydrazine hydrate was diluted in 100 mL of pure water to obtain a dilute hydrazine hydrate solution; under cooling conditions, the dilute hydrazine hydrate solution was slowly added to the dilute nitric acid solution in a reactor, and the mixture was stirred while controlling the reaction temperature to be below 20°C to obtain a hydrazine nitrate reaction solution.

[0036] A polyamide reverse osmosis membrane is installed inside the membrane housing of the membrane filtration system. The feed pump pumps the hydrazine nitrate reaction solution into the filtration system. The material pump is turned on, and the filtration pressure is controlled at 3 MPa and the filtration temperature at 20°C to achieve circulating filtration. The permeate is returned to the reaction vessel for further reaction. By continuously adding raw materials, hydrazine nitrate can be prepared continuously and on a large scale with a yield of over 99% and a purity of over 99%.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing ionic energetic compounds via reaction-filtration coupling, characterized in that, Includes the following steps: a. First, the raw materials are added to the reaction vessel to prepare ionic energetic compounds and impurity molecules, and a reaction solution is obtained; b. Select a reactive filtration membrane and install it into the membrane filtration system; c. Use a feed pump to pump the reaction solution into the membrane filtration system. Use the feed pump to control the input of the reaction solution, and use a material pump and pressure regulating valve to adjust the filtration pressure of the membrane filtration system. At the same time, control the filtration temperature and use a temperature sensor for real-time monitoring. d. The permeate produced after passing through the membrane filtration system is returned to the reaction vessel for circulation filtration until a high-purity ionic energetic compound solution is obtained. e. Increase the filtration pressure to concentrate the ionic energetic compound solution to obtain a high-concentration solution; In step c, the filtration pressure of the membrane filtration device system is adjusted using a material pump and a pressure regulating valve. Combined with the filtration flux and energy consumption, the filtration pressures for different membrane filtration device systems are: microfiltration <0.4 MPa, ultrafiltration <0.7 MPa, nanofiltration and reverse osmosis 1.5~3 MPa. In step c, the filtration temperature is controlled by the system cooling device, and the controlled filtration temperature range is 4-55℃. In step e, the high rejection rate of ionic energetic compounds by the reactive filtration membrane is utilized to concentrate the ionic energetic compounds by increasing the filtration pressure. Considering energy consumption, yield, and filtration flux, the filtration pressures for different membrane filtration systems are: microfiltration 0.3~0.4 MPa, ultrafiltration 0.5~0.7 MPa, nanofiltration 3-4 MPa, and reverse osmosis 5-7 MPa.

2. The method for preparing ionic energetic compounds by reaction-filtration coupling according to claim 1, characterized in that, In step a, the types of reaction vessels selected include reaction vessels, polymerization vessels, storage tanks, and stirred tanks that facilitate chemical reactions.

3. The method for preparing ionic energetic compounds by reaction-filtration coupling according to claim 2, characterized in that, In step b, the types of membrane filtration devices selected include microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, and the types of reaction filtration membranes selected include ceramic membranes, hollow fiber membranes, and organic spiral wound membranes.

4. The method for preparing ionic energetic compounds by reaction-filtration coupling according to claim 3, characterized in that, In step d, the permeate refluxed to the reaction vessel reacts further with the added raw materials to synthesize ionic energetic compounds, thereby increasing their yield and productivity.

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