阅读说明：本技术 一种过氧化二苯甲酰废料的处理方法 (Method for treating dibenzoyl peroxide waste ) 是由 应立 应志耀 于 2019-09-25 设计创作，主要内容包括：本发明涉及有机过氧化物处理领域,尤其涉及一种过氧化二苯甲酰废料的处理方法。本发明的处理方法包括：将水、氢氧化钠、水合肼和BPO废料混合,进行第一氧化还原反应,得到第一混合物；将第一混合物与双氧水混合,进行第二氧化还原反应,得到第二混合物；将第二混合物依次进行热分解、冷却和第一次固液分离,得到滤渣和第一滤液；向第一滤液中加入盐酸至pH值为1～2,酸析后,进行第二次固液分离,得到苯甲酸粗品和第二滤液；向第二滤液中加入钠离子的碱性溶液进行酸碱中和,蒸发浓缩后,进行第三次固液分离,得到氯化钠。本发明的处理方法能够对已发生分解或受污染严重的BPO进行有效处理,且得到的苯甲酸和氯化钠可回收再利用。(The invention relates to the field of organic peroxide treatment, in particular to a method for treating dibenzoyl peroxide waste. The processing method of the invention comprises the following steps: mixing water, sodium hydroxide, hydrazine hydrate and BPO waste to perform a first oxidation-reduction reaction to obtain a first mixture; mixing the first mixture with hydrogen peroxide, and carrying out a second redox reaction to obtain a second mixture; sequentially carrying out thermal decomposition, cooling and first solid-liquid separation on the second mixture to obtain filter residue and first filtrate; adding hydrochloric acid into the first filtrate until the pH value is 1-2, and performing solid-liquid separation for the second time after acid precipitation to obtain a benzoic acid crude product and a second filtrate; and adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, evaporating and concentrating, and performing solid-liquid separation for the third time to obtain sodium chloride. The treatment method can effectively treat the BPO which is decomposed or seriously polluted, and the obtained benzoic acid and the sodium chloride can be recycled.)

1. A method for treating dibenzoyl peroxide waste is characterized by comprising the following steps:

(1) mixing water, sodium hydroxide, hydrazine hydrate and BPO waste to perform a first oxidation-reduction reaction to obtain a first mixture;

(2) mixing the first mixture with hydrogen peroxide, and carrying out a second redox reaction to obtain a second mixture;

(3) sequentially carrying out thermal decomposition, cooling and first solid-liquid separation on the second mixture to obtain filter residue and first filtrate;

(4) adding hydrochloric acid into the first filtrate until the pH value is 1-2, and performing solid-liquid separation for the second time after acid precipitation to obtain a benzoic acid crude product and a second filtrate;

(5) and adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, and performing solid-liquid separation for the third time after evaporation concentration to obtain a solid material sodium chloride.

2. The treatment method according to claim 1, wherein the content of BPO in the BPO waste is 40-60 wt.%.

3. The process of claim 1 wherein the molar ratio of BPO in the sodium hydroxide, hydrazine hydrate and BPO waste is 4: (1-1.5): 2.

4. the treatment method according to claim 1, wherein the first oxidation-reduction reaction is carried out in step (1), and the amount of sodium hydroxide is 3.5 to 6 wt.% of the total amount of each raw material.

5. The treatment method according to claim 1, wherein the temperature of the first oxidation reaction in the step (1) is 30 to 70 ℃ and the time is 1 to 4 hours.

6. The treatment method according to claim 1, wherein the temperature of the second redox reaction in the step (2) is normal temperature, and the time is 0.5-2 h.

7. The treatment method according to claim 1, wherein the thermal decomposition in the step (3) is carried out at a temperature of 70 to 100 ℃ for 15 to 60 minutes.

8. The process of claim 1, wherein the alkaline solution of sodium ions in step (5) comprises a sodium hydroxide solution, a sodium carbonate solution or a sodium bicarbonate solution.

9. The treatment method according to claim 1 or 8, wherein the pH value of the system after the acid-base neutralization in the step (5) is 5-7.

10. The process according to claim 1 or 8, wherein the solid-to-liquid ratio after the evaporation concentration in the step (5) is 1 kg: (0.5-2) L.

Technical Field

The invention relates to the technical field of organic peroxide treatment, in particular to a method for treating dibenzoyl peroxide waste.

Background

Dibenzoyl peroxide (BPO) is a diacyl peroxide and is also an initiator with the widest application, and is mainly used as an initiator or a cross-linking agent for solvent polymerization of PVC, polyacrylonitrile, acrylic ester and vinyl acetate, graft polymerization of chloroprene rubber, SBS and methyl methacrylate, curing of unsaturated polyester resin, organic glass adhesive and the like; as vulcanizing or crosslinking agents for silicone and fluororubbers in the rubber industry; it can also be used as bleaching agent and oxidant in chemical production. In the preparation process of BPO, the BPO often runs out and drips and is polluted by mechanical impurities, and the collected polluted BPO finished products cannot be sold due to unqualified quality. Or in the production process of BPO, the BPO often happens to be seriously self-decomposed due to production accidents or long-time storage, and the decomposed BPO waste materials can not be recycled through simple treatment, thereby losing the utilization value.

Disclosure of Invention

The invention aims to provide a method for treating dibenzoyl peroxide waste, which can treat BPO which is decomposed or seriously polluted, is safe and environment-friendly, and can recycle the treated product.

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

the invention provides a method for treating dibenzoyl peroxide waste, which comprises the following steps:

(1) mixing water, sodium hydroxide, hydrazine hydrate and BPO waste to perform a first oxidation-reduction reaction to obtain a first mixture;

(2) mixing the first mixture with hydrogen peroxide, and carrying out a second redox reaction to obtain a second mixture;

(3) sequentially carrying out thermal decomposition, cooling and first solid-liquid separation on the second mixture to obtain filter residue and first filtrate;

(4) adding hydrochloric acid into the first filtrate until the pH value is 1-2, and performing solid-liquid separation for the second time after acid precipitation to obtain a benzoic acid crude product and a second filtrate;

(5) and adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, and performing solid-liquid separation for the third time after evaporation concentration to obtain a solid material sodium chloride.

Preferably, the content of BPO in the BPO waste material is 40-60 wt.%.

Preferably, the molar ratio of the sodium hydroxide, hydrazine hydrate and BPO in the BPO waste is 4: (1-1.5): 2.

preferably, in the step (1), the amount of sodium hydroxide used in the first oxidation-reduction reaction is 3.5 to 6 wt.% of the total amount of the raw materials.

Preferably, the temperature of the first oxidation reaction in the step (1) is 30-70 ℃ and the time is 1-4 h.

Preferably, the temperature of the second redox reaction in the step (2) is normal temperature, and the time is 0.5-2 h.

Preferably, the thermal decomposition temperature in the step (3) is 70-100 ℃, and the time is 15-60 min.

Preferably, the alkaline solution of sodium ions in step (5) includes a sodium hydroxide solution, a sodium carbonate solution or a sodium bicarbonate solution.

Preferably, the pH value of the system after acid-base neutralization in the step (5) is 5-7.

Preferably, the mass ratio of the evaporated and concentrated solution in the step (5) is 1 kg: (0.5-2) L.

The invention provides a method for treating dibenzoyl peroxide waste, which comprises the following steps: (1) mixing water, sodium hydroxide, hydrazine hydrate and BPO waste to perform a first oxidation-reduction reaction to obtain a first mixture; (2) mixing the first mixture with hydrogen peroxide, and carrying out a second redox reaction to obtain a second mixture; (3) sequentially carrying out thermal decomposition, cooling and first solid-liquid separation on the second mixture to obtain filter residue and first filtrate; (4) adding hydrochloric acid into the first filtrate until the pH value is 1-2, and performing solid-liquid separation for the second time after acid precipitation to obtain a benzoic acid crude product and a second filtrate; (5) and adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, and performing solid-liquid separation for the third time after evaporation concentration to obtain a solid material sodium chloride. The method can effectively treat the BPO which is decomposed or seriously polluted, the hydrazine hydrate is selected to treat the BPO which is seriously polluted, reaction products are nitrogen, benzoic acid and sodium chloride, and the nitrogen exists in a large amount in the air and is pollution-free; the benzoic acid and the sodium chloride can be recycled. The treatment method disclosed by the invention is pollution-free, safe and environment-friendly.

Detailed Description

The invention provides a method for treating dibenzoyl peroxide waste, which comprises the following steps:

(1) mixing water, sodium hydroxide, hydrazine hydrate and BPO waste to perform a first oxidation-reduction reaction to obtain a first mixture;

(2) mixing the first mixture with hydrogen peroxide, and carrying out a second redox reaction to obtain a second mixture;

(3) sequentially carrying out thermal decomposition, cooling and first solid-liquid separation on the second mixture to obtain filter residue and first filtrate;

(4) adding hydrochloric acid into the first filtrate until the pH value is 1-2, and performing solid-liquid separation for the second time after acid precipitation to obtain a benzoic acid crude product and a second filtrate;

(5) and adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, and performing solid-liquid separation for the third time after evaporation concentration to obtain a solid material sodium chloride.

According to the invention, water, sodium hydroxide, hydrazine hydrate and BPO waste are mixed to carry out a first oxidation-reduction reaction, so as to obtain a first mixture.

In the invention, the content of BPO in the BPO waste material is preferably 40-60 wt.%, and the balance is preferably water and impurities. In the present invention, the impurities preferably include oligomers and mechanical impurities formed by polymerization of aromatic hydrocarbon functional groups in the molecular structure of BPO when it undergoes self-decomposition. The source of the BPO waste is not particularly critical to the present invention and any BPO waste from sources well known in the art may be used. In the present invention, the molar ratio of the sodium hydroxide, hydrazine hydrate and BPO in the BPO waste is preferably 4: (1-1.5): 2. in the oxidation-reduction reaction, the amount of sodium hydroxide is preferably 3.5 to 6 wt.%, more preferably 4.0 to 5.5 wt.%, based on the total amount of the raw materials. In the present invention, the sodium hydroxide is preferably used in the form of an aqueous sodium hydroxide solution; the concentration of the sodium hydroxide aqueous solution is preferably 20-32 wt.%, more preferably 25-32 wt.%. In the present invention, the hydrazine hydrate is preferably used in the form of an aqueous solution of hydrazine hydrate; the concentration of the hydrazine hydrate aqueous solution is preferably 70-85 wt.%, and more preferably 80-85 wt.%.

In the invention, the temperature of the first oxidation-reduction reaction is preferably 30-70 ℃, and more preferably 35-60 ℃; the time is preferably 1 to 4 hours, and more preferably 1 to 3 hours. In the present invention, the first redox reaction is preferably carried out under stirring conditions. The invention has no special requirement on the stirring speed, and can ensure that the first oxidation-reduction reaction is smoothly carried out. In the first oxidation-reduction reaction process, hydrazine hydrate and BPO are subjected to oxidation-reduction reaction in the presence of sodium hydroxide to generate sodium benzoate and nitrogen.

After the first mixture is obtained, the first mixture is mixed with hydrogen peroxide to carry out a second redox reaction to obtain a second mixture.

In the invention, the mass concentration of the hydrogen peroxide is preferably 20-70 wt.%; the dosage of the hydrogen peroxide is preferably adjusted according to the amount of residual hydrazine hydrate in the solution after the hydrazine hydrate in the step (1) and the BPO in the BPO waste material react in an alkaline environment.

In the invention, the temperature of the second redox reaction is preferably normal temperature, i.e. no additional heating or cooling is required, and is further preferably 20-40 ℃; the time of the second redox reaction is preferably 0.5-2 h. In the present invention, the second redox reaction is preferably carried out under stirring conditions. The invention has no special requirement on the stirring speed, and can ensure that the second oxidation reduction reaction is smoothly carried out. In the second oxidation reduction reaction process, hydrogen peroxide continuously reacts with the hydrazine hydrate remained in the reaction in the step (1), the residual hydrazine hydrate in the mixed system is removed, and water and nitrogen are generated. At this point, the second mixture obtained comprises mainly water, sodium benzoate, impurities from the BPO waste and hydrogen peroxide.

After the second mixture is obtained, the second mixture is subjected to thermal decomposition, cooling and first solid-liquid separation in sequence to obtain filter residue and first filtrate.

In the invention, the thermal decomposition temperature is preferably 70-100 ℃, and more preferably 80-90 ℃; the time is preferably 15 to 60min, and more preferably 15 to 30 min. In the invention, the thermal decomposition is preferably carried out under the condition of stirring, and the invention has no special requirement on the stirring speed and can ensure that the thermal decomposition reaction sequence is carried out. In the thermal decomposition process, residual hydrogen peroxide in the previous step is decomposed to generate water and oxygen.

After thermal decomposition, the present invention cools the decomposed system. In the present invention, the cooling is performed by water bath cooling, the temperature after cooling is preferably 20 ℃, and during the cooling process, insoluble substances are gradually separated out from the system, wherein the insoluble substances are oligomers and mechanical impurities formed by polymerization of aromatic hydrocarbon functional groups in the molecular structure when BPO undergoes self-decomposition. Impurities obtained by oxidation-reduction reaction of oligomers and the like formed when BPO undergoes self-decomposition have certain fluidity under reaction conditions, and after cooling, the viscosity is increased to form a solid, which is favorable for liquid-solid separation.

After the cooling is finished, the system is subjected to first solid-liquid separation to obtain filter residue and first filtrate. In the invention, the first solid-liquid separation is preferably realized by centrifugation, the centrifugation rotating speed in the solid-liquid separation process is preferably 800-2000 rpm, and the centrifugation time is preferably 5-20 min. The main components of the obtained first filtrate are sodium benzoate and water; the filter residue is oligomer and mechanical impurity formed by polymerization of aromatic hydrocarbon functional groups in the molecular structure of BPO when the BPO undergoes self-decomposition.

After the first filtrate is obtained, adding hydrochloric acid into the first filtrate until the pH value is 1-2, and after acid precipitation, performing solid-liquid separation for the second time to obtain a benzoic acid crude product and a second filtrate.

In the invention, the concentration of the hydrochloric acid is preferably 20-36 wt.%. After hydrochloric acid is added, in the process of adjusting the pH value to 1-2, sodium benzoate in the first filtrate reacts with the hydrochloric acid to generate benzoic acid and sodium chloride, and a benzoic acid crude product is gradually separated out. The method has no special requirement on the acid precipitation time, and no solid is precipitated. According to the invention, the pH value after hydrochloric acid is added is controlled to be 1-2, so that benzoic acid can be ensured to be separated out, and excessive hydrochloric acid is prevented from being added. And the hydrochloric acid can avoid introducing other impurity anions into a sodium chloride production system.

In the invention, the second solid-liquid separation is preferably realized by centrifugation, the centrifugation rotating speed in the solid-liquid separation process is preferably 800-2000 rpm, and the centrifugation time is preferably 5-20 min. The main components of the second filtrate obtained after solid-liquid separation are hydrochloric acid and sodium chloride; the benzoic acid crude product obtained after solid-liquid separation is washed to be neutral, and then the drying purity can reach 99 percent, so that the benzoic acid crude product can be used for industrial purposes such as alkyd resin and the like.

After the second filtrate is obtained, adding an alkaline solution of sodium ions into the second filtrate for acid-base neutralization, evaporating and concentrating, and performing solid-liquid separation for the third time to obtain a solid material sodium chloride.

In the present invention, the alkaline solution of sodium ions preferably includes a sodium hydroxide solution, a sodium carbonate solution, or a sodium bicarbonate solution, and more preferably a sodium hydroxide solution. In the invention, the concentration of the alkaline solution of sodium ions is preferably 20-32 wt.%. In the invention, the pH value of the system after acid-base neutralization is preferably 5-7, so that salt evaporation treatment can be conveniently carried out subsequently. In the acid-base neutralization process, the residual hydrochloric acid in the previous step reacts with the alkaline solution of sodium ions to generate sodium chloride.

After acid-base neutralization, the system obtained after neutralization is evaporated and concentrated. In the present invention, the solid-to-liquid ratio after the evaporation concentration is preferably 1 kg: (0.5-2) L. In the evaporation and concentration process, a large amount of sodium chloride is separated out from the system.

After the evaporation concentration is finished, the invention carries out solid-liquid separation for the third time, and the obtained solid material is sodium chloride. In the invention, the third solid-liquid separation is preferably realized by centrifugation, the centrifugation rotating speed in the solid-liquid separation process is preferably 800-2000 rpm, and the centrifugation time is preferably 5-20 min. And (3) performing solid-liquid separation to obtain a solid material, namely sodium chloride. After the third solid-liquid separation, the method preferably further comprises drying the separated sodium chloride, wherein the dried sodium chloride has high purity which can reach 98-99 wt%, and the whiteness can reach more than 80%.

The following examples are provided to illustrate the treatment of dibenzoyl peroxide waste according to the present invention, but they should not be construed as limiting the scope of the present invention.