阅读说明：本技术 一种浸取-相分离-精馏耦合分离精制苯酚的方法 (Method for separating and refining phenol by leaching-phase separation-rectification coupling ) 是由 王大为 许文林 于 2020-07-13 设计创作，主要内容包括：本发明涉及一种以丙酮-水混合溶剂为浸取剂浸取分离苯酚钠和氢氧化钠固态混合物,通过浸取-相分离-精馏耦合分离精制苯酚的方法,在分离精制得到苯酚的同时,使氢氧化钠及浸取剂得以循环利用。本发明的分离方法充分利用了被分离物系的特点以及分离过程的特性,不仅分离操作简单易行、操作费用低,而且有价成分利用率高,是符合绿色化工发展要求的清洁生产方法。(The invention relates to a method for leaching and separating solid mixture of sodium phenolate and sodium hydroxide by using an acetone-water mixed solvent as a leaching agent, and separating and refining phenol by leaching-phase separation-rectification coupling, wherein the sodium hydroxide and the leaching agent are recycled while the phenol is obtained by separation and refining. The separation method of the invention fully utilizes the characteristics of the separated material system and the characteristics of the separation process, not only has simple and easy separation operation and low operation cost, but also has high utilization rate of valuable components, and is a clean production method which meets the development requirement of green chemical industry.)

1. A method for extracting-separating-rectifying coupling separation and refining phenol, in particular to a method for extracting and separating solid mixture of sodium phenolate and sodium hydroxide by using an acetone-water mixed solvent, then separating and refining the mixture by liquid-liquid phase separation and rectifying operation to obtain phenol, and simultaneously recycling the sodium hydroxide and extracting agent, which is characterized by comprising the following steps:

(1) preparing a leaching agent: mixing acetone and water to prepare an acetone-water mixed solvent, and taking the acetone-water mixed solvent as an extracting agent to enter the next step;

(2) leaching sodium phenolate: leaching and separating the solid mixture of sodium phenolate and sodium hydroxide in a leaching device by using the leaching agent prepared in the previous step to dissolve the sodium phenolate in the solid material into a liquid phase, and feeding the material subjected to the leaching operation to the next step;

(3) solid-liquid separation: carrying out solid-liquid separation on the material obtained in the last step in solid-liquid separation equipment, wherein the solid phase is a crude sodium hydroxide product, the material can be directly used as a reactant in the process of converting phenol into sodium phenate, and can also be further processed to obtain a sodium hydroxide product, and the liquid phase material enters the next step;

(4) and (3) evaporating and removing acetone: removing acetone from the liquid-phase material obtained in the last step through evaporation operation in evaporation equipment, allowing the gas-phase material to enter the next step, and allowing the evaporation concentrate to enter the sixth step;

(5) gas phase condensation: condensing the gas-phase material obtained in the last step into liquid by a condenser, wherein the material can be used as a raw material for preparing the leaching agent in the first step;

(6) and (3) sulfuric acid neutralization: in a neutralization device, neutralizing the sodium phenolate subjected to the solvent removal by evaporation in the fourth step with sulfuric acid to generate phenol and sodium sulfate, and feeding the materials to the next step;

(7) liquid-liquid separation: in liquid-liquid separation equipment, performing oil-water phase separation on the material obtained in the last step, further processing the water phase material to obtain sodium sulfate and water, and refining the oil phase material which is a crude phenol product in the next step;

(8) and (3) rectifying and refining phenol: and (3) rectifying the material in the last step in a rectifying tower, wherein the distillate at the top of the tower is phenol, and the generated extremely small amount of kettle liquid is treated as waste liquid.

2. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: in the first-step leaching agent preparation process, the volume ratio of water to acetone is 1.0:100-10.0: 100.

3. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: in the second leaching process, the ratio of the mass of the sodium phenate in the mixture of the sodium phenate and the sodium hydroxide to the volume of the leaching agent is 1.0kg:5.0L-1.0kg: 50L.

4. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: in the third step of solid-liquid separation, the solid-liquid separation equipment can be any one of filter pressing equipment, centrifugal filtration equipment, blade type filtration equipment, pipeline type filtration equipment and vacuum filtration equipment.

5. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: the evaporation apparatus of the fourth step may be an atmospheric evaporation apparatus or a vacuum evaporation apparatus.

6. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: during the sixth sulfuric acid neutralization step, the solution is neutralized to a pH of 5-6.

7. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: the device in the liquid-liquid separation process in the seventh step is any one of a settling type, a centrifugal type or a high-efficiency oil-water separator.

8. The method for separating and refining the phenol by the coupling of leaching-phase separation-rectification according to claim 1, which is characterized in that: the eighth step of the rectification separation process can be operated continuously or intermittently.

Technical Field

The invention relates to a method for extracting-separating-rectifying coupling separation and refining phenol, in particular to a method for extracting and separating a solid mixture of sodium phenolate and sodium hydroxide by adopting an acetone-water mixed solvent, then separating and refining the mixture through liquid-liquid phase separation and rectification operation to obtain phenol, and simultaneously recycling the sodium hydroxide and an extracting agent, belonging to the technical field of chemical separation.

Background

In general, when phenol-containing materials are subjected to evaporation dehydration treatment, in order to reduce the volatilization of phenol and protect phenolic hydroxyl groups from chemical reaction, sodium hydroxide is added into a phenol aqueous solution, so that phenol and sodium hydroxide react to generate sodium phenolate which is difficult to volatilize and has stable chemical properties. Meanwhile, in order to complete the reaction, an excess of sodium hydroxide is usually added, so that a solid mixture of sodium phenolate and sodium hydroxide is formed after the evaporation dehydration and drying treatment.

At present, the method for processing solid mixture of sodium phenolate and sodium hydroxide is to add sulfuric acid or hydrochloric acid into the material to react with sodium hydroxide in the mixture to generate sodium salt (sodium sulfate, sodium chloride); meanwhile, sodium phenolate reacts with acid to generate free phenol, and the phenol is recovered by utilizing the characteristic of easy volatilization of the free phenol. The method mainly has the following problems:

(1) sulfuric acid or hydrochloric acid is added as a neutralizer in the separation process, so that acid is consumed;

(2) the added sulfuric acid or hydrochloric acid reacts with sodium hydroxide, and the sodium hydroxide in the material is also consumed;

(3) the treatment method has the outstanding problems that the added acid reacts with sodium hydroxide to generate sodium salt, the sodium salt has low utilization value, is difficult to recycle, can only be used as waste to carry out solid waste treatment, and the treatment difficulty of the solid waste is relatively high.

Therefore, the process for separating the sodium phenolate and the sodium hydroxide is reasonable in research and development process, simple in method, low in cost and high in utilization rate of valuable components, so that phenol and other materials can be recycled and recycled, and the process has industrial application value and remarkable economic and social benefits.

Disclosure of Invention

The invention aims to solve the defects of the prior art, develop a clean and environment-friendly method for separating and refining phenol by coupling leaching-phase separation-rectification, which has the advantages of reasonable process, simple method, low cost, high utilization rate of valuable components and resource utilization of other materials while separating and refining phenol.

The technical scheme for realizing the purpose is as follows:

a method for extracting-separating-rectifying coupling separation and refining phenol, in particular to a method for extracting and separating solid mixture of sodium phenolate and sodium hydroxide by using an acetone-water mixed solvent, then separating and refining the mixture by liquid-liquid phase separation and rectifying operation to obtain phenol, and simultaneously recycling the sodium hydroxide and extracting agent, which is characterized by comprising the following steps:

(1) preparing a leaching agent: mixing acetone and water to prepare an acetone-water mixed solvent, and taking the acetone-water mixed solvent as an extracting agent to enter the next step;

(2) leaching sodium phenolate: leaching and separating the solid mixture of sodium phenolate and sodium hydroxide in a leaching device by using the leaching agent prepared in the previous step to dissolve the sodium phenolate in the solid material into a liquid phase, and feeding the material subjected to the leaching operation to the next step;

(3) solid-liquid separation: carrying out solid-liquid separation on the material obtained in the last step in solid-liquid separation equipment, wherein the solid phase is a crude sodium hydroxide product, the material can be directly used as a reactant in the process of converting phenol into sodium phenate, and can also be further processed to obtain a sodium hydroxide product, and the liquid phase material enters the next step;

(4) and (3) evaporating and removing acetone: removing acetone from the liquid-phase material obtained in the last step through evaporation operation in evaporation equipment, allowing the gas-phase material to enter the next step, and allowing the evaporation concentrate to enter the sixth step;

(5) gas phase condensation: condensing the gas-phase material obtained in the last step into liquid by a condenser, wherein the material can be used as a raw material for preparing the leaching agent in the first step;

(6) and (3) sulfuric acid neutralization: in a neutralization device, neutralizing the sodium phenolate subjected to the solvent removal by evaporation in the fourth step with sulfuric acid to generate phenol and sodium sulfate, and feeding the materials to the next step;

(7) liquid-liquid separation: in liquid-liquid separation equipment, performing oil-water phase separation on the material obtained in the last step, further processing the water phase material to obtain sodium sulfate and water, and refining the oil phase material which is a crude phenol product in the next step;

(8) and (3) rectifying and refining phenol: and (3) rectifying the material in the last step in a rectifying tower, wherein the distillate at the top of the tower is phenol, and the generated extremely small amount of kettle liquid is treated as waste liquid.

Furthermore, the volume ratio of water to acetone in the preparation process of the primary leaching agent is 1.0:100-10.0: 100.

Further, in the second leaching process, the ratio of the mass of the sodium phenate to the volume of the leaching agent in the mixture of the sodium phenate and the sodium hydroxide is 1.0kg:5.0L-1.0kg: 50L.

Further, in the third step of solid-liquid separation, the solid-liquid separation apparatus may be any one of a filter press apparatus, a centrifugal filter apparatus, a blade type filter apparatus, a pipeline type filter apparatus and a vacuum filtration apparatus.

Further, the evaporation apparatus of the fourth step may be an atmospheric evaporation apparatus or a vacuum evaporation apparatus.

Further, during the sixth step of sulfuric acid neutralization operation, the pH of the solution is neutralized to 5 to 6.

Furthermore, the device in the liquid-liquid separation process in the seventh step is any one of a settling type, a centrifugal type or a high-efficiency oil-water separator.

Furthermore, the eighth step of the rectification separation process can be operated continuously or intermittently

The main principle and characteristics of the application of the invention are as follows:

(1) the solubility difference between sodium phenolate and sodium hydroxide in acetone and water is utilized. Sodium phenolate and sodium hydroxide are both readily soluble in water, but sodium hydroxide is poorly soluble in acetone, whereas sodium phenolate has some solubility in acetone. The solubility of sodium phenolate in acetone increased with increasing temperature, and was about 22.0g/100ml under reflux conditions.

(2) The difference in solubility of sodium phenolate and sodium hydroxide in an acetone-water mixed solvent is utilized. In order to improve the solubility of sodium phenolate in the leaching agent, an acetone-water mixed solvent is innovatively developed as the leaching agent, namely a small amount of water is added into acetone, and the acetone-water mixed solvent can greatly improve the solubility of the sodium phenolate.

(3) The solid mixture of sodium phenolate and sodium hydroxide is separated by leaching. The acetone-water mixed solvent is used as a leaching agent, and sodium phenolate in the mixture is leached into a liquid phase through leaching operation, so that the separation of the sodium phenolate and the sodium hydroxide is realized.

(4) The acetone is evaporated and removed by utilizing the characteristic that the acetone is volatile. Because the sodium phenolate is not easy to generate chemical change after being heated, the sodium phenolate is not easy to volatilize as salt, and the acetone is easy to volatilize, the acetone can be removed by adopting an evaporation method, and the acetone can be used as a raw material of an extracting agent for recycling after being condensed by a condenser.

(5) The phenol and the water can be separated by a liquid-liquid phase separation method by utilizing the characteristic that the phenol and the water are not mutually soluble at room temperature. Because the solubility of phenol in water and water in phenol is low, phenol and water are easy to separate after standing, and the separation of phenol and water is realized by a liquid-liquid phase separation method.

(6) The phenol is separated and refined by adopting a rectification method. The boiling point of the phenol is far lower than 300 ℃, and the crude phenol obtained by oil-water separation can be refined by adopting the conventional rectification separation technology, so that the product meeting the requirements of the standard (GB/T339-2019 industrial synthetic phenol) can be obtained.

The main process equipment for realizing the invention is as follows: leaching equipment, solid-liquid separation equipment, liquid-liquid separation equipment, rectification equipment and the like.

The technical scheme has the advantages that: the acetone-water mixed solvent is used as an extracting agent to extract and separate the solid mixture of sodium phenolate and sodium hydroxide, and the sodium hydroxide and the extracting agent are recycled while the phenol is obtained by separation and refining through extraction-phase separation-rectification coupling. The concrete points are as follows:

(1) an acetone-water mixed solvent containing a small amount of water is used as an extracting agent. The acetone-water mixed solvent containing a small amount of water is used as the leaching agent, so that the solubility of the sodium phenolate in the leaching agent is obviously increased, and the separation process still has higher selectivity. The sodium phenolate with the required purity can be obtained by adjusting the water content in the leaching agent, the solid-liquid ratio of the leaching operation, the leaching separation times and the like. The use of an acetone-water mixed solvent containing a small amount of water as the leaching agent not only makes the separation of the solid mixture of sodium phenate and sodium hydroxide technically feasible, but also makes the separation process economically advantageous.

(2) The separation process thoroughly overcomes the defects of the process for neutralizing and separating the sodium phenolate and the sodium hydroxide by adding acid, does not need to consume acid, does not lose the sodium hydroxide in materials, and does not generate sodium salt solid waste.

(3) The evaporation acetone removal technology is adopted, so that the operation is simple, the recovered acetone can be recycled as a raw material of the leaching agent, the resources are saved, and the discharge amount of wastes is greatly reduced.

(4) The phenol and the water are separated by liquid-liquid phase by utilizing the characteristic that the phenol and the water are not mutually soluble at room temperature, the separation operation is simple and easy, and the energy consumption of the process is low.

(5) The phenol is refined by adopting a conventional rectification method, so that a product meeting the requirement of the standard (GB/T339-.

The method of the invention is particularly suitable for separating and recovering phenol from the mixture of sodium phenolate and sodium hydroxide. The method makes full use of the characteristics of the separated material system and the characteristics of the separation process, not only has simple and easy separation operation, but also has high utilization rate of valuable components, and is a clean production method which meets the development requirements of green chemical industry.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.