Method for recovering dimethyl sulfoxide from energetic organic waste liquid

Abstract

The invention provides a method for recovering dimethyl sulfoxide from energetic organic waste liquid, and belongs to the technical field of organic waste liquid recovery. According to the invention, a three-stage coupling process of molecular sieve dehydration, stabilization treatment of removing nitro compounds by macroporous adsorption resin, and recovery of dimethyl sulfoxide by reduced pressure rectification is adopted, and the molecular sieve can accurately intercept water molecules in the organic waste liquid without causing solvent loss, and can be regenerated and reused for multiple times; the macroporous adsorption resin can realize high-capacity adsorption of the nitro compound, and the regeneration process is stable and not easy to collapse; the reduced pressure rectification device avoids the generation of dimethyl sulfoxide pyrolysis byproducts, and improves the purity of refined and recycled products. Through the operation processes of molecular sieve dehydration, stabilization treatment and vacuum distillation, the operation safety of recovering dimethyl sulfoxide from the energetic organic waste liquid is improved, and the recovered dimethyl sulfoxide can be reused in the energetic material preparation process.

Description

Technical Field

[0001] The invention relates to the technical field of organic waste liquid recovery, and in particular to a method for recovering dimethyl sulfoxide from energetic organic waste liquid. Background Art

[0002] Dimethyl sulfoxide (DMSO), a highly polar aprotic solvent, plays an irreplaceable role in the preparation of energetic materials. Its strong solubility effectively disperses energetic material molecules while ensuring process safety. Because large amounts of DMSO are used in the preparation of energetic materials, the recycling and reuse of DMSO-containing organic wastewater is crucial to reduce production costs and address environmental concerns.

[0003] Vacuum distillation is an effective method for recycling and reusing DMSO wastewater, reducing production costs while also minimizing the discharge of three wastes. However, energetic organic wastewater, in addition to DMSO, also contains high concentrations of nitro compounds, some acidic energetic substances, and water, necessitating specialized treatment technologies for its recovery.

[0004] Currently, the recovery of DMSO-containing energetic organic wastewater primarily relies on a separation and purification process called "dehydration by vacuum distillation followed by rectification." This process is complex in terms of equipment and operation, and consumes significant amounts of energy. Furthermore, as DMSO evaporates during the recovery process, the nitro compounds in the wastewater concentrate at high temperatures and easily decompose to form toxic gases, increasing the safety risks of refined recovery. Summary of the Invention

[0005] In view of this, the present invention aims to provide a method for recovering dimethyl sulfoxide from energetic organic waste liquid. The recovery method provided by the present invention can reduce the difficulty of recovering dimethyl sulfoxide, improve the purity and utilization rate of dimethyl sulfoxide in the recovered product, and meet the demand for reuse of energetic organic solvents.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for recovering dimethyl sulfoxide from energetic organic waste liquid, comprising the following steps:

[0008] (1) mixing the energetic organic waste liquid with a molecular sieve and performing a dehydration treatment to obtain a dehydrated energetic organic waste liquid, wherein the water content of the dehydrated energetic organic waste liquid is less than 0.1 wt %;

[0009] (2) mixing the dehydrated energetic organic waste liquid with a macroporous adsorption resin and performing a stabilization treatment to obtain a stabilized solution;

[0010] (3) determining the content of dimethyl sulfoxide in the stabilization treatment solution, and when the content of dimethyl sulfoxide is ≥97 wt %, reusing the stabilization treatment solution as a solvent for the preparation of the energetic material;

[0011] When the content of dimethyl sulfoxide is less than 97 wt %, the stabilization solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

[0012] Preferably, the components of the energetic organic waste liquid include dimethyl sulfoxide, water and nitro compounds;

[0013] Calculated by mass percentage, the content of dimethyl sulfoxide in the energetic organic waste liquid is 80-90%, and the content of water is 5-6%.

[0014] Preferably, the molecular sieve is a 3A molecular sieve, the particle size of the molecular sieve is φ3-5 mm, and the bulk density is 0.69-0.75 g / mL;

[0015] The mass ratio of the molecular sieve to the volume of the energetic organic waste liquid is 15-30 g:100 mL.

[0016] Preferably, the dehydration treatment is carried out at room temperature for 6 to 12 hours.

[0017] Preferably, the macroporous adsorption resin is a styrene-divinylphenyl copolymer macroporous adsorption resin;

[0018] The specific surface area of ​​the macroporous adsorption resin is ≥800m 2 / g, particle size is 560~710μm;

[0019] The volume ratio of the mass of the macroporous adsorption resin to the energetic organic waste liquid is 15-30 g:100 mL.

[0020] Preferably, the stabilization treatment temperature is 50-60°C and the time is 3-6 hours;

[0021] The stabilization treatment is carried out under stirring conditions, and the stirring rate is 150-200 rpm.

[0022] Preferably, the step (1) is replaced by: passing the energetic organic waste liquid through a dehydration column for dehydration treatment to obtain dehydrated energetic organic waste liquid; the filler of the dehydration column is a molecular sieve;

[0023] And / or the step (2) is replaced by:

[0024] The dehydrated energetic organic waste liquid is passed through an adsorption column for stabilization to obtain a stabilized solution; the filler of the adsorption column is a macroporous adsorption resin.

[0025] Preferably, after the stabilization treatment solution is reused as a solvent in the preparation of energetic materials, the obtained energetic organic waste liquid is repeated in steps (1), (2) and step (3), and the maximum number of reuses is 8 to 10 times; when the number of reuses reaches the maximum number of reuses, the reused energetic organic waste liquid is repeated in steps (1) and (2), and the obtained stabilization treatment solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

[0026] Preferably, the vacuum distillation pressure is -0.095 to -0.1 MPa, the vacuum distillation temperature is 90 to 100° C., and the reflux ratio is 6 to 8:1.

[0027] Preferably, after the vacuum distillation, the obtained dimethyl sulfoxide fraction is mixed with a molecular sieve and dehydrated to obtain refined dimethyl sulfoxide.

[0028] The present invention provides a method for recovering dimethyl sulfoxide from energetic organic waste liquid, which is characterized in that it comprises the following steps: (1) mixing the energetic organic waste liquid with a molecular sieve and performing a dehydration treatment to obtain a dehydrated energetic organic waste liquid, wherein the water content of the dehydrated energetic organic waste liquid is less than 0.1 wt%; (2) mixing the dehydrated energetic organic waste liquid with a macroporous adsorption resin and performing a stabilization treatment to obtain a stabilized solution; (3) determining the content of dimethyl sulfoxide in the stabilized solution, and when the content of dimethyl sulfoxide is ≥97 wt%, reusing the stabilized solution as a solvent for the preparation of energetic materials; and when the content of dimethyl sulfoxide is less than 97 wt%, performing a vacuum distillation on the stabilized solution to obtain refined dimethyl sulfoxide. In order to overcome the problems of the existing distillation technology for recovering energetic organic solvents, such as the influence of reaction raw materials, energetic substances and moisture on the safety of refining and the purity of dimethyl sulfoxide recovery products, the present invention proposes a three-stage coupling process of molecular sieve dehydration + macroporous adsorption resin to remove nitro compounds for stabilization treatment + vacuum distillation to recover dimethyl sulfoxide, which can reduce the difficulty of recovering dimethyl sulfoxide, improve the purity and utilization rate of dimethyl sulfoxide in the recovered products, and meet the recycling needs of energetic organic solvents. Specifically, compared with the traditional process of using silica gel and CaO for dehydration, molecular sieves can accurately intercept water molecules in organic waste liquid without causing solvent loss, and the regeneration method is simple and reusable without secondary pollution; macroporous adsorption resins (such as styrene-divinylphenyl copolymers) can achieve high-capacity adsorption of nitro compounds and acidic energetic substances, and the regeneration process is stable without structural collapse; the vacuum distillation device avoids the generation of high-temperature decomposition by-products of dimethyl sulfoxide, thereby improving the purity of the refined recovery product. The invention improves the safety of the operation of recovering dimethyl sulfoxide from energetic organic waste liquid through molecular sieve dehydration, stabilization treatment and vacuum distillation operation process, and the recovered dimethyl sulfoxide can be reused in the energetic material preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A process flow chart of a method for recovering dimethyl sulfoxide from energetic organic waste liquid;

[0030] Figure 2 These are sample images before and after stabilization treatment and after distillation in Example 1. DETAILED DESCRIPTION

[0031] The present invention provides a method for recovering dimethyl sulfoxide from energetic organic waste liquid, comprising the following steps:

[0032] (1) mixing the energetic organic waste liquid with a molecular sieve and performing a dehydration treatment to obtain a dehydrated energetic organic waste liquid, wherein the water content of the dehydrated energetic organic waste liquid is less than 0.1 wt %;

[0033] (2) mixing the dehydrated energetic organic waste liquid with a macroporous adsorption resin and performing a stabilization treatment to obtain a stabilized solution;

[0034] (3) determining the content of dimethyl sulfoxide in the stabilization treatment solution, and when the content of dimethyl sulfoxide is ≥97 wt %, reusing the stabilization treatment solution as a solvent for the preparation of the energetic material;

[0035] When the content of dimethyl sulfoxide is less than 97 wt %, the stabilization solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

[0036] The present invention mixes energetic organic waste liquid with molecular sieve and performs dehydration treatment to obtain dehydrated energetic organic waste liquid. In the present invention, the components of the energetic organic waste liquid preferably include dimethyl sulfoxide, water and nitro compounds. In the present invention, the content of dimethyl sulfoxide in the energetic organic waste liquid is preferably 85-90%, more preferably 86-89%, and the content of water is preferably 5-6%. In the present invention, the pH value of the energetic organic waste liquid is preferably 1-3, and the chromaticity is preferably 10 4 ~10 5 .

[0037] In the present invention, the molecular sieve is preferably a 3A molecular sieve. In the present invention, the particle size of the molecular sieve is preferably φ3 to 5 mm, and the bulk density is preferably 0.69 to 0.75 g / mL, more preferably 0.7 to 0.72 g / mL. Before use, the molecular sieve is preferably activated. In the present invention, the activation method preferably comprises the following steps:

[0038] The molecular sieve was calcined and activated under an inert atmosphere.

[0039] In the present application, the temperature of the calcination activation is preferably 350-400℃, the holding time is preferably 3-4h, and the heating rate to the calcination activation temperature is preferably 2-4℃ / min. After the calcination activation, the present application preferably cools to room temperature naturally.

[0040] In the present application, the mass-to-volume ratio of the molecular sieve to the energetic organic waste liquid is preferably 15-30g:100mL, and more preferably 15-20g:100mL.

[0041] The present application does not have special requirements for the mixing method, and a mixing method well known to those skilled in the art can be used, such as stirring mixing. In the present application, the temperature of the dehydration treatment is preferably room temperature, and the time is preferably 6-12h, and more preferably 8-10h. After the dehydration treatment, the present application preferably performs solid-liquid separation on the obtained dehydration treatment liquid, and the solid-liquid separation is preferably vacuum filtration. The present application preferably stores the obtained dehydration treatment energetic organic waste liquid in the dark. In the present application, the water content of the dehydration treatment energetic organic waste liquid is <0.1wt%.

[0042] Alternatively, the present application dehydrates the energetic organic waste liquid through a dehydration column to obtain a dehydration treatment energetic organic waste liquid. In the present application, the packing of the dehydration column is a molecular sieve, and the optional types of the molecular sieve are the same as above and will not be repeated here. In the present application, the volume of the packing is preferably 1.5m 3 , and the speed of the organic waste liquid through the molecular sieve is preferably 1m 3 / h.

[0043] After obtaining the dehydration treatment energetic organic waste liquid, the present application mixes the dehydration treatment energetic organic waste liquid with a macroporous adsorption resin to perform a stabilization treatment to obtain a stabilization treatment solution. In the present application, the macroporous organic resin is preferably a macroporous adsorption resin, which is a styrene-divinylbenzene copolymer macroporous adsorption resin; the specific surface area of the macroporous adsorption resin is preferably ≥800m 2 / g, and more preferably 800-1000m 2 / g, and the particle size is preferably 560-710μm, and more preferably 600-700μm. In the present application, the mass-to-volume ratio of the macroporous adsorption resin to the energetic organic waste liquid is preferably 15-30g:100mL, and more preferably 15-20g:100mL.

[0044] In the present invention, the stabilization treatment temperature is preferably 50-60°C, more preferably 55°C; the stabilization time is preferably 3-6 hours, more preferably 4-5 hours; the stabilization treatment is preferably carried out under stirring conditions, and the stirring rate is preferably 150-200 rpm. After the stabilization treatment, the present invention preferably performs solid-liquid separation on the resulting stabilization solution, preferably by vacuum filtration. The present invention preferably stores the resulting stabilization solution in the dark.

[0045] Alternatively, the present invention passes the dehydrated energetic organic waste liquid through an adsorption column for stabilization to obtain a stabilized solution. In the present invention, the filler of the adsorption column is a macroporous organic resin. The optional types of the macroporous organic resin are the same as those described above and will not be described in detail here. In the present invention, the volume of the filler is preferably 1.5m 3 The speed of the material passing through the adsorption resin is preferably 1m 3 / h.

[0046] In the present invention, the content of dimethyl sulfoxide in the stabilization treatment solution is preferably 96-98%, and the content of water is preferably 0.06-0.1%.

[0047] After obtaining the stabilization treatment solution, the present invention determines the content of dimethyl sulfoxide in the stabilization treatment solution. When the content of dimethyl sulfoxide is ≥97wt%, the stabilization treatment solution is reused as a solvent for the preparation of energetic materials; when the content of dimethyl sulfoxide is <97wt%, the stabilization treatment solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

[0048] In the present invention, after the stabilized solution is reused as a solvent in the preparation of energetic materials, the obtained energetic organic waste liquid is reused repeatedly through steps (1), (2), and (3), and the maximum number of such reuses is 8 to 10 times. When the maximum number of reuses is reached, the reused energetic organic waste liquid is reused through steps (1) and (2), and the obtained stabilized solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide. In other words, after being reused 8 to 10 times, the dimethyl sulfoxide content in the stabilized solution is no longer measured, and the dimethyl sulfoxide is directly purified by vacuum distillation.

[0049] In the present invention, the temperature of the vacuum distillation is preferably 90-100° C., and the reflux ratio is preferably 6-8: 1. After the vacuum distillation, the purity of dimethyl sulfoxide in the obtained dimethyl sulfoxide fraction is preferably 97%-98%, and the water content is preferably 0.35-0.40%.

[0050] In the present application, the reduced pressure distillation is followed by mixing the obtained dimethyl sulfoxide fraction with molecular sieve for dehydration treatment to obtain refined dimethyl sulfoxide. In the present application, the optional type and dosage of the molecular sieve are the same as described above, and will not be repeated here.

[0051] In the present application, the mass / volume ratio of the molecular sieve to the dimethyl sulfoxide fraction is preferably 15 g: 100 mL. The temperature of the dehydration treatment is preferably room temperature, and the time is preferably 6-12 h.

[0052] In the present application, after the dehydration treatment, the purity of dimethyl sulfoxide in the obtained refined dimethyl sulfoxide is preferably 97-98%, and the water content is preferably ≤0.08%.

[0053] In the present application, the process flow chart of the method for recovering dimethyl sulfoxide from the energetic organic waste liquid is shown in Figure 1 .

[0054] The method for recovering dimethyl sulfoxide from the energetic organic waste liquid provided by the present application will be described in detail below with reference to the examples, but they should not be understood as limiting the scope of protection of the present application.

[0055] Example 1

[0056] The energetic organic waste liquid to be recovered used in this example is strongly acidic (pH 3), with a density of 1.1394 g / cm 3 , a color of 100000, a red-black solution, a large amount of nitro compounds, an initial water content of 5.7%, and a DMSO content of 89.50%.

[0057] The molecular sieve used is 3A type molecular sieve with a particle size of Φ3-5 mm, purchased from Shanghai Lusi Experimental Instrument Co., Ltd.

[0058] The macroporous adsorption resin used is a styrene-divinylbenzene copolymer macroporous adsorption resin with a specific surface area of ≥800 m 2 / g, a particle size of 560-710 μm, and a model of Amberlite TM XAD16N polymeric adsorbent.

[0059] The method for recovering dimethyl sulfoxide from the energetic organic waste liquid adopts the following steps:

[0060] (1) Take 100 mL of the energetic organic waste liquid to be recovered and place it in a brown reagent bottle, add 15 g (15% w / v) of activated molecular sieve, stir at room temperature for 12 h, then vacuum filter, and take the filtrate for storage in the dark for standby use; wherein the activation method is: place the molecular sieve in a tube furnace, activate at 400°C for 3 h under the protection of inert gas argon (the heating rate is 2°C / min), and naturally cool to room temperature.

[0061] (2) The filtrate was transferred to a clean brown reagent bottle, and 15 g of styrene-divinylphenyl copolymer macroporous adsorption resin was added at 15% (w / v). The mixture was stirred at 60°C and 200 rpm for 3 h to remove nitrobenzene substances in the organic waste liquid. The solution was vacuum filtered to obtain a stabilized solution, which was stored in the dark for later use.

[0062] (3) After stabilization with molecular sieves and macroporous adsorption resins, the nitro compounds were effectively removed, the solution became clear, the chromaticity decreased to 1000, the pH value increased to 8, the water content decreased to 0.08%, and the purity of DMSO increased to 97%, which can be directly reused in the production process of energetic materials.

[0063] The obtained stabilization solution was subjected to vacuum distillation at a distillation pressure of -0.1 MPa, a distillation temperature of 90-100° C., and a reflux ratio of 8:1 to obtain a dimethyl sulfoxide fraction after distillation.

[0064] The samples before and after stabilization treatment and after distillation are shown in the figure below. Figure 2 As shown, Figure 2 In the figure, A is the energetic organic waste liquid to be recovered, B is the stabilization treatment solution, and C is the dimethyl sulfoxide fraction after distillation.

[0065] The comparison of the main physical properties of the samples before and after stabilization treatment and after distillation is shown in Table 1.

[0066] Table 1 Comparison of the main physical properties of samples before and after stabilization treatment and after distillation

[0067]

[0068]

[0069] Example 2

[0070] The stabilized solution obtained in Example 1 was reused in the energetic material preparation process. After being reused 8 times, the obtained energetic organic waste liquid repeated steps (1) and (2) of Example 1 to obtain a stabilized solution. The obtained stabilized solution still met the direct reuse standard of energetic organic solvents.

[0071] 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for recovering dimethyl sulfoxide from energetic organic waste liquid, characterized in that: The following steps are involved: (1) mixing the energetic organic waste liquid with a molecular sieve and performing a dehydration treatment to obtain a dehydrated energetic organic waste liquid, wherein the water content of the dehydrated energetic organic waste liquid is less than 0.1 wt %; (2) mixing the dehydrated energetic organic waste liquid with a macroporous adsorption resin and performing a stabilization treatment to obtain a stabilized solution; (3) determining the content of dimethyl sulfoxide in the stabilization treatment solution, and when the content of dimethyl sulfoxide is ≥97 wt %, reusing the stabilization treatment solution as a solvent for the preparation of the energetic material; When the content of dimethyl sulfoxide is less than 97 wt %, the stabilization solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

2. The method according to claim 1, characterized in that The components of the energetic organic waste liquid include dimethyl sulfoxide, water and nitro compounds; Calculated by mass percentage, the content of dimethyl sulfoxide in the energetic organic waste liquid is 80-90%, and the content of water is 5-6%.

3. The method according to claim 1, characterized in that The molecular sieve is a 3A molecular sieve having a particle size of φ3-5 mm and a bulk density of 0.69-0.75 g / mL; The mass ratio of the molecular sieve to the volume of the energetic organic waste liquid is 15-30 g:100 mL.

4. The method according to claim 1 or 3, characterized in that The dehydration treatment is performed at room temperature for 6 to 12 hours.

5. The method according to claim 1, wherein The macroporous adsorption resin is a styrene-divinylphenyl copolymer macroporous adsorption resin; The specific surface area of ​​the macroporous adsorption resin is ≥800m 2 / g, particle size is 560~710μm; The volume ratio of the mass of the macroporous adsorption resin to the energetic organic waste liquid is 15-30 g:100 mL.

6. The method according to claim 1 or 5, characterized in that The stabilization treatment temperature is 50-60°C and the time is 3-6 hours; The stabilization treatment is carried out under stirring conditions, and the stirring rate is 150-200 rpm.

7. The method according to claim 1, characterized in that The step (1) is replaced by: passing the energetic organic waste liquid through a dehydration column for dehydration treatment to obtain a dehydrated energetic organic waste liquid; the filler of the dehydration column is a molecular sieve; And / or the step (2) is replaced by: The dehydrated energetic organic waste liquid is passed through an adsorption column for stabilization to obtain a stabilized solution; the filler of the adsorption column is a macroporous adsorption resin.

8. The method according to claim 1, characterized in that After the stabilization treatment solution is reused as a solvent in the preparation of energetic materials, the obtained energetic organic waste liquid is reused by repeating steps (1), (2) and step (3), and the maximum number of reuses is 8 to 10 times; when the number of reuses reaches the maximum number of reuses, the reused energetic organic waste liquid is repeated by repeating steps (1) and (2), and the obtained stabilization treatment solution is subjected to vacuum distillation to obtain refined dimethyl sulfoxide.

9. The method according to claim 1 or 8, characterized in that The pressure of the vacuum distillation is -0.095 to -0.1 MPa, the temperature of the vacuum distillation is 90 to 100° C., and the reflux ratio is 6 to 8:

1.

10. The method according to claim 1 or 8, characterized in that After the vacuum distillation, the method further includes mixing the obtained dimethyl sulfoxide fraction with a molecular sieve and performing a dehydration treatment to obtain refined dimethyl sulfoxide.

Images