BTTN washing post-treatment method based on membrane separation multistage extraction technology

Abstract

The invention discloses a BTTN washing post-treatment method based on a membrane separation multi-stage extraction technology, which comprises the following steps: cooling a synthesized BTTN crude product mixed solution to 25-40 DEG C, then mixing the BTTN crude product mixed solution and 25-40 DEG C pure water according to the flow velocity of (1-2): 1, and injecting into a first-stage liquid-liquid membrane separator for first separation; mixing the organic phase separated from the first-stage liquid-liquid membrane separator with a sodium carbonate solution with the mass fraction of 5%-10% according to the flow velocity of (1-2): 1, and injecting the mixture into a second-stage liquid-liquid membrane separator for separation; mixing the organic phase separated from the second-stage liquid-liquid membrane separator with a sodium carbonate solution with the mass fraction of 5%-10% according to the flow velocity of (1-2): 1, and injecting the mixture into a third-stage liquid-liquid membrane separator for separation, wherein the organic phase obtained after separation is a treated target product. According to the method, continuous and automatic impurity removal and purification of the BTTN product are achieved, and the separation efficiency is remarkably improved compared with that of traditional liquid separation.

Description

Technical Field

[0001] This invention relates to a post-washing treatment method for BTTN based on membrane separation multi-stage extraction technology, belonging to the field of energetic materials technology. Background Technology

[0002] 1,2,4-Butanetriol trinitrate (BTTN) is an important energetic plasticizer widely used in solid propellants and high-energy propellants. It has excellent low-temperature performance and can effectively improve the low-temperature mechanical properties of propellants and enhance their safety in use.

[0003] Currently, significant progress has been made in the synthesis of BTTN using a batch overflow / microreactor. However, the post-synthesis processing still relies on traditional methods such as static stratification, intermittent multiple water washing, and alkaline washing, which have the following drawbacks: 1) Low separation efficiency: Traditional separation methods require long periods of static stratification, affecting overall production efficiency; 2) Poor washing effect: Batch operation leads to unstable washing effects, sometimes requiring repeated washing, which is cumbersome, prone to emulsification and failure, affecting the purity and recovery rate of the final product, and difficult to automate; 3) Process continuity interruption: The front end uses a batch overflow / microreactor for continuous synthesis, but the post-processing is still intermittent, causing process interruptions; 4) Safety hazards: Frequent manual handling of energetic materials poses safety risks; 5) High solvent consumption: Multiple washings result in a large amount of wastewater, imposing a heavy environmental burden.

[0004] Liquid-liquid membrane separation technology is a high-efficiency continuous separation technology based on membrane separation that has been developed in recent years. Utilizing the selective permeation principle of special membrane materials, it can achieve efficient separation of liquid and liquid phases in continuous flow, demonstrating unique advantages in various organic synthesis fields. However, its application in the field of high-energy materials, especially in BTTN production, has been rarely reported. This invention employs a combined membrane separation and multi-stage extraction approach to achieve a multi-stage continuous separation integrated system for hazardous high-viscosity organic compounds such as BTTN, improving production efficiency and process safety. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of low efficiency, uneven washing, difficulty in continuous operation, and poor safety in the post-processing of crude BTTN mixture in existing processes, and to realize the automation and continuous operation of the entire BTTN production process. To this end, a BTTN washing post-processing method based on membrane separation multi-stage extraction technology is provided.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] The present invention provides a post-washing treatment method for BTTN based on membrane separation multi-stage extraction technology, which specifically includes the following steps:

[0008] 1) Cool the synthesized crude BTTN mixture to 25℃~40℃, and then mix the crude BTTN mixture with pure water at 25℃~40℃ (1~2):1 and inject the mixture into the first-stage liquid-liquid membrane separator for the first separation.

[0009] 2) The organic phase separated from the first-stage liquid-liquid membrane separator is mixed with a sodium carbonate solution with a mass fraction of 5% to 10% at a flow rate of (1 to 2): 1 and then injected into the second-stage liquid-liquid membrane separator for further separation.

[0010] 3) The organic phase separated from the second-stage liquid-liquid membrane separator is mixed with a sodium carbonate solution with a mass fraction of 5% to 10% at a flow rate of (1 to 2): 1 and then injected into the third-stage liquid-liquid membrane separator for separation. The organic phase obtained after separation is the target product after treatment.

[0011] The first-stage liquid-liquid membrane separator, the second-stage liquid-liquid membrane separator, and the third-stage liquid-liquid membrane separator all use hydrophobic PTFE membranes, and the transmembrane pressure difference is 0.3 to 0.5 bar.

[0012] Beneficial effects

[0013] The method of this invention enables continuous automated impurity removal and purification of BTTN products, significantly improving separation efficiency compared to traditional liquid-liquid separation, reducing the time required for traditional static stratification from several hours to within minutes; detergent utilization is increased by more than 60%, reducing solvent / wastewater consumption; it can be seamlessly integrated with the synthesis reaction system, improving the continuity and intelligence of the overall production process; multi-stage precise washing ensures thorough removal of impurities, achieving a product purity of over 99% and better stability; the system is modular, compact, and occupies a small area, making it suitable for large-scale, integrated plant applications; the fully enclosed operation, highly corrosion-resistant equipment, and reduced safety risks make it particularly suitable for high-energy / hazardous materials production environments. Attached Figure Description

[0014] Figure 1 This is a schematic flowchart of the BTTN washing post-treatment method of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Example 1:

[0017] like Figure 1 As shown, the BTTN washing post-treatment method based on membrane separation multi-stage extraction technology of the present invention specifically includes the following steps:

[0018] 1) Cool the synthesized crude BTTN mixture to 40℃, then mix the crude BTTN mixture with pure water at 40℃ and inject it into the first-stage liquid-liquid membrane separator for the first separation. The flow rate of the crude BTTN mixture is 20mL / min, the flow rate of the pure water is 10mL / min, the flow rate of the mixture injected into the first-stage liquid-liquid membrane separator is 10mL / min, and the pressure difference of the first-stage liquid-liquid membrane separator is controlled at 0.5bar.

[0019] 2) The organic phase separated from the first-stage liquid-liquid membrane separator is mixed with a 5% sodium carbonate solution at 40°C and then injected into the second-stage liquid-liquid membrane separator for further separation. The flow rate of the organic phase separated from the first-stage liquid-liquid membrane separator is 20 mL / min, the flow rate of the 5% sodium carbonate solution is 10 mL / min, the flow rate of the mixture injected into the second-stage liquid-liquid membrane separator is 10 mL / min, and the pressure difference of the second-stage liquid-liquid membrane separator is controlled at 0.4 bar.

[0020] 3) The organic phase separated from the second-stage liquid-liquid membrane separator is mixed with a 5% sodium carbonate solution at 40°C and then injected into the third-stage liquid-liquid membrane separator for further separation. The organic phase obtained after separation is the target product after treatment. The flow rate of the organic phase separated from the second-stage liquid-liquid membrane separator is 20 mL / min, the flow rate of the 5% sodium carbonate solution is 10 mL / min, the flow rate of the mixture injected into the third-stage liquid-liquid membrane separator is 10 mL / min, and the pressure difference of the first-stage liquid-liquid membrane separator is controlled at 0.3 bar.

[0021] The first-stage liquid-liquid membrane separator, the second-stage liquid-liquid membrane separator, and the third-stage liquid-liquid membrane separator all use hydrophobic PTFE membranes.

[0022] The purity of the processed target product obtained in Example 1 was tested, and the product purity was 99.2%. Example 2:

[0023] The present invention provides a BTTN washing post-treatment method based on membrane separation-multi-stage extraction technology, which specifically includes the following steps:

[0024] 1) Cool the synthesized crude BTTN mixture to 25°C, then mix the crude BTTN mixture with pure water at 25°C and inject it into the first-stage liquid-liquid membrane separator for the first separation. The flow rate of the crude BTTN mixture is 10 mL / min, the flow rate of the pure water is 10 mL / min, the flow rate of the mixture injected into the first-stage liquid-liquid membrane separator is 10 mL / min, and the pressure difference of the first-stage liquid-liquid membrane separator is controlled at 0.5 bar.

[0025] 2) The organic phase separated from the first-stage liquid-liquid membrane separator is mixed with a 10% sodium carbonate solution at 25°C and then injected into the second-stage liquid-liquid membrane separator for further separation. The flow rate of the organic phase separated from the first-stage liquid-liquid membrane separator is 10 mL / min, the flow rate of the 5% sodium carbonate solution is 10 mL / min, the flow rate of the mixture injected into the second-stage liquid-liquid membrane separator is 10 mL / min, and the pressure difference of the second-stage liquid-liquid membrane separator is controlled at 0.4 bar.

[0026] 3) The organic phase separated from the second-stage liquid-liquid membrane separator is mixed with a 10% sodium carbonate solution at 25°C and then injected into the third-stage liquid-liquid membrane separator for further separation. The organic phase obtained after separation is the target product after treatment. The flow rate of the organic phase separated from the second-stage liquid-liquid membrane separator is 10 mL / min, the flow rate of the 5% sodium carbonate solution is 10 mL / min, the flow rate of the mixture injected into the third-stage liquid-liquid membrane separator is 10 mL / min, and the pressure difference of the first-stage liquid-liquid membrane separator is controlled at 0.3 bar.

[0027] The first-stage liquid-liquid membrane separator, the second-stage liquid-liquid membrane separator, and the third-stage liquid-liquid membrane separator all use hydrophobic PTFE membranes.

[0028] The purity of the processed target product obtained in Example 2 was tested, and the product purity was 99.5%.

Claims

1. A post-washing treatment method for BTTN based on membrane separation multi-stage extraction technology, characterized in that, Specifically, the following steps are included: 1) Cool the synthesized crude BTTN mixture to 25℃~40℃, and then mix the crude BTTN mixture with pure water at 25℃~40℃ (1~2):1 and inject the mixture into the first-stage liquid-liquid membrane separator for the first separation. 2) The organic phase separated from the first-stage liquid-liquid membrane separator is mixed with a sodium carbonate solution with a mass fraction of 5% to 10% at a flow rate of (1 to 2): 1 and then injected into the second-stage liquid-liquid membrane separator for further separation. 3) The organic phase separated from the second-stage liquid-liquid membrane separator is mixed with a sodium carbonate solution with a mass fraction of 5% to 10% at a flow rate of (1 to 2): 1 and then injected into the third-stage liquid-liquid membrane separator for separation. The organic phase obtained after separation is the target product after treatment.

2. The BTTN washing post-treatment method based on membrane separation multi-stage extraction technology as described in claim 1, characterized in that, The first-stage liquid-liquid membrane separator, the second-stage liquid-liquid membrane separator, and the third-stage liquid-liquid membrane separator all use hydrophobic PTFE membranes, and the transmembrane pressure difference is 0.3 to 0.5 bar.

Images