阅读说明：本技术 酚类产品中碱性氮化物的分离系统及方法 (Separation system and method for alkaline nitride in phenol product ) 是由 赵宁 王雄雄 述子清 刘宁 姬锐 王彦军 刘伟 赵修洪 于 2019-09-06 设计创作，主要内容包括：本发明公开了一种酚类产品中碱性氮化物的分离系统及方法。系统包括：萃取单元,用于利用第一萃取剂和第二萃取剂对待处理酚类产品萃取处理,并送出含第二萃取剂和酚类化合物的第一混合物及含第一萃取剂和碱性氮化物的第二混合物；蒸馏分离单元,用于接收所述第一混合物和将所述第一混合物蒸馏处理,并送出第二萃取剂和酚类化合物；反萃取单元,用于接收所述第二混合物和采用反萃取剂对所述第二混合物反萃取处理,并送出所述第一萃取剂以及含反萃取剂和碱性氮化物的第三混合物。采用本发明的系统和方法能高效地分离酚类产品中的碱性氮化物,且节能环保。(The invention discloses a system and a method for separating alkaline nitride from a phenol product. The system comprises: the extraction unit is used for extracting and treating the phenolic product to be treated by utilizing the first extracting agent and the second extracting agent, and sending a first mixture containing the second extracting agent and the phenolic compound and a second mixture containing the first extracting agent and the alkaline nitride; a distillation separation unit for receiving and distillatively treating the first mixture and sending out a second extractant and a phenolic compound; a stripping unit for receiving the second mixture and stripping the second mixture with a stripping agent and sending out the first extraction agent and a third mixture containing the stripping agent and the alkaline nitride. The system and the method can efficiently separate the alkaline nitride from the phenol products, and are energy-saving and environment-friendly.)

1. A system for separating basic nitrogen compounds from phenolic products, comprising:

the extraction unit is provided with a first outlet and a second outlet, and is used for carrying out extraction treatment on a phenolic product to be treated by using a first extracting agent and a second extracting agent, and sending out a first mixture containing the second extracting agent and phenolic compounds from the first outlet and sending out a second mixture containing the first extracting agent and basic nitrides from the second outlet;

a distillation separation unit, an inlet of the distillation separation unit is connected with the first outlet of the extraction unit, the distillation separation unit is provided with a third outlet and a fourth outlet, and the distillation separation unit is used for receiving the first mixture and distilling the first mixture, sending a second extractant out from the third outlet and sending a phenolic compound out from the fourth outlet;

and the inlet of the stripping unit is connected with the second outlet of the extraction unit, the stripping unit is provided with a fifth outlet and a sixth outlet, and the stripping unit is used for receiving the second mixture, carrying out stripping treatment on the second mixture by using a stripping agent, sending out the first extraction agent from the fifth outlet, and sending out a third mixture containing the stripping agent and the alkaline nitride from the sixth outlet.

2. The system of claim 1, wherein the extraction unit comprises:

the centrifugal extraction equipment is provided with the first outlet and the second outlet, and is used for carrying out single-stage extraction treatment or more than two-stage extraction treatment on the phenolic product to be treated and carrying out liquid-liquid separation on the extraction treatment product;

or, stirring extraction equipment and with the exit linkage's of stirring extraction equipment liquid-liquid separation equipment, liquid-liquid separation equipment has first export and second export, wherein, stirring extraction equipment is used for to wait to handle phenol product extraction processing, liquid-liquid separation equipment is used for extracting the processing product liquid-liquid separation.

3. The system of claim 1, wherein the distillation separation unit comprises a distillation apparatus having an inlet connected to the first outlet, the distillation apparatus having the third outlet and the fourth outlet;

the distillation equipment is simple distillation equipment, rectification equipment or flash distillation equipment.

4. The system according to claim 1, wherein the stripping unit comprises a stripping apparatus, the feed inlet of the stripping apparatus is connected to the second outlet, the feed inlet of the stripping apparatus is connected to a stripping agent supply apparatus, and the stripping apparatus has the fifth outlet and a sixth outlet;

the back extraction equipment is an extraction tower, a centrifugal extractor or a stirring extractor.

5. The system of claim 1, further comprising a polishing separation unit having an inlet connected to the sixth outlet of the stripping unit, the polishing separation unit having a seventh outlet and an eighth outlet, the polishing separation unit being configured to receive the third mixture and perform a polishing separation process on the third mixture, and to send a stripping agent through the seventh outlet and an alkaline nitride through the eighth outlet.

6. The system of claim 5, wherein the polishing separation unit comprises a polishing apparatus having an inlet connected to the sixth outlet, the polishing apparatus having the seventh outlet and an eighth outlet;

the refining equipment is adsorption refining equipment or rectification refining equipment.

7. The system of claim 1, further comprising:

a first mixer connected to a first inlet of the extraction unit, the first mixer being configured to mix a second extractant with the phenolic product to be treated;

and the second mixer is connected with a second inlet of the extraction unit and is used for mixing the eutectic solvent and water to obtain the first extractant.

8. The system of claim 7,

a third outlet of the distillation separation unit is connected with an inlet of the first mixer so as to recycle the second extractant sent by the distillation separation unit;

and the fifth outlet of the back-extraction unit is connected with the inlet of the second mixer so as to recycle the first extractant sent by the back-extraction unit.

9. A method for separating alkaline nitrides from phenolic products is characterized by comprising the following steps:

extracting a to-be-treated phenol product by using a first extracting agent and a second extracting agent, and performing liquid-liquid separation to obtain a first mixture containing the second extracting agent and a phenol compound and a second mixture containing the first extracting agent and an alkaline nitride, wherein the first extracting agent comprises a ternary eutectic solvent, the ternary eutectic solvent is synthesized by proline, choline chloride and oxalic acid, and the second extracting agent adopts a weak-polarity solvent;

distilling and separating the first mixture to obtain a second extracting agent and a phenolic compound;

and carrying out back extraction treatment on the second mixture by using a weak polar solvent as a back extractant to obtain a first extractant and a third mixture containing the back extractant and the alkaline nitride.

10. The method according to claim 9, wherein the ternary eutectic solvent is synthesized from proline, choline chloride and oxalic acid in a molar ratio of 0.5-1: 1-3.

11. The method of claim 9,

the first extractant is an aqueous solution of the ternary eutectic solvent, wherein the mass ratio of the ternary eutectic solvent to water is 5: 1-1: 5, and the mass ratio of the ternary eutectic solvent to the phenol product to be treated is 2: 1-1: 10;

and/or the second extracting agent is selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether and benzene, and the mass ratio of the second extracting agent to the phenol product to be treated is 10: 1-1: 2;

and/or the stripping agent is selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether and benzene.

12. The method of claim 9,

the extraction treatment is single-stage extraction treatment or more than two-stage extraction treatment;

and/or the temperature of the extraction treatment is 20-60 ℃, preferably 30-50 ℃.

Technical Field

The invention belongs to the technical field of separation, and particularly relates to a system and a method for separating alkaline nitride from a phenol product.

Background

The phenol product is obtained by processing phenol-containing fraction obtained by distilling coal tar, wherein the phenol product contains organic nitride, mainly alkaline nitride such as pyridine. The presence of nitrides affects the stability of the phenolic product and its subsequent processing. Therefore, it is necessary to separate and remove the nitrogen compounds from the phenolic products. At present, alkaline nitrides in phenol products are removed mainly by adopting a steam blowing method and an acid washing method. However, both of these methods produce large amounts of waste water and have serious pollution risks. The treatment of waste water greatly increases the burden of enterprises.

Based on this, the present application is specifically proposed.

Disclosure of Invention

In view of the technical problems in the prior art, the present invention provides a system and a method for separating basic nitrogen compounds from phenol products, which can efficiently separate the basic nitrogen compounds from the phenol products and reduce the generation of waste water.

The invention provides a separation system for alkaline nitrides in phenolic products, which comprises:

the extraction unit is provided with a first outlet and a second outlet, and is used for extracting and treating the phenolic product to be treated by using a first extracting agent and a second extracting agent, and sending out a first mixture containing the second extracting agent and phenolic compounds from the first outlet and sending out a second mixture containing the first extracting agent and alkaline nitrides from the second outlet;

the inlet of the distillation separation unit is connected with the first outlet of the extraction unit, the distillation separation unit is provided with a third outlet and a fourth outlet, and the distillation separation unit is used for receiving the first mixture, distilling the first mixture, sending the second extractant out from the third outlet and sending the phenolic compound out from the fourth outlet;

and the inlet of the stripping unit is connected with the second outlet of the extraction unit, the stripping unit is provided with a fifth outlet and a sixth outlet, and the stripping unit is used for receiving the second mixture, stripping the second mixture by using a stripping agent, sending the first extracting agent out from the fifth outlet, and sending a third mixture containing the stripping agent and the alkaline nitride out from the sixth outlet.

According to a first aspect of the invention, the extraction unit comprises a centrifugal extraction device having a first outlet and a second outlet, the centrifugal extraction device being adapted to perform a single-stage extraction treatment or more than two-stage extraction treatment of the phenolic product to be treated and to perform liquid-liquid separation of the extraction treatment product;

according to a first aspect of the present invention, the extraction unit comprises an agitation extraction apparatus and a liquid-liquid separation apparatus connected to an outlet of the agitation extraction apparatus, the liquid-liquid separation apparatus having a first outlet and a second outlet, wherein the agitation extraction apparatus is used for extraction treatment of the phenolic product to be treated, and the liquid-liquid separation apparatus is used for liquid-liquid separation of the extraction treatment product.

According to a first aspect of the invention, a distillation separation unit comprises a distillation apparatus, an inlet of the distillation apparatus being connected to a first outlet, the distillation apparatus having a third outlet and a fourth outlet;

the distillation equipment is simple distillation equipment, rectification equipment or flash evaporation equipment.

According to a first aspect of the invention, the stripping unit comprises a stripping apparatus, the feed inlet of the stripping apparatus being connected to the second outlet, the feed inlet of the stripping apparatus being connected to a stripping agent supply apparatus, the stripping apparatus having a fifth outlet and a sixth outlet;

the back extraction equipment is an extraction tower, a centrifugal extractor or a stirring extractor.

According to the first aspect of the invention, the system further comprises a refining separation unit, an inlet of the refining separation unit is connected with a sixth outlet of the back-extraction unit, the refining separation unit is provided with a seventh outlet and an eighth outlet, and the refining separation unit is used for receiving the third mixture, carrying out refining separation treatment on the third mixture, sending out the back-extraction agent from the seventh outlet and sending out the alkaline nitride from the eighth outlet.

According to a first aspect of the invention, the refining separation unit comprises a refining apparatus, the inlet of which is connected to the sixth outlet, the refining apparatus having a seventh outlet and an eighth outlet;

the refining equipment is adsorption refining equipment or rectification refining equipment.

According to the first aspect of the invention, the system further comprises:

the first mixer is connected with a first inlet of the extraction unit and is used for mixing the second extractant and the phenolic product to be treated;

and the second mixer is connected with a second inlet of the extraction unit and is used for mixing the eutectic solvent and water to obtain the first extractant.

According to a first aspect of the invention, the third outlet of the distillation separation unit is connected to the inlet of the first mixer for recycling the second extractant from the distillation separation unit.

According to the first aspect of the invention, the fifth outlet of the stripping unit is connected to the inlet of the second mixer for recycling the first extractant from the stripping unit.

The second aspect of the invention provides a method for separating alkaline nitrides from phenolic products, which comprises the following steps:

extracting a to-be-treated phenolic product by using a first extracting agent and a second extracting agent, and performing liquid-liquid separation to obtain a first mixture containing the second extracting agent and a phenolic compound and a second mixture containing the first extracting agent and an alkaline nitride, wherein the first extracting agent comprises a ternary eutectic solvent, the ternary eutectic solvent is synthesized by proline, choline chloride and oxalic acid, and the second extracting agent adopts a weak-polarity solvent;

distilling and separating the first mixture to obtain a second extracting agent and a phenolic compound;

and (3) carrying out back extraction treatment on the second mixture by using a weak polar solvent as a back extractant to obtain a first extractant and a third mixture containing the back extractant and the alkaline nitride.

According to the second aspect of the invention, the ternary eutectic solvent is synthesized from proline, choline chloride and oxalic acid according to a molar ratio of 0.5-1: 1-3.

According to the second aspect of the invention, the first extractant is an aqueous solution of a ternary eutectic solvent, wherein the mass ratio of the ternary eutectic solvent to water is 5: 1-1: 5, and the mass ratio of the ternary eutectic solvent to the phenolic product to be treated is 2: 1-1: 10;

according to the second aspect of the invention, the second extracting agent is selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether and benzene, and the mass ratio of the second extracting agent to the phenolic product to be treated is 10: 1-1: 2.

According to a second aspect of the invention, the stripping agent is selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether and benzene.

According to the second aspect of the present invention, the extraction treatment is a single-stage extraction treatment or an extraction treatment of two or more stages.

According to the second aspect of the invention, the temperature of the extraction treatment is 20 ℃ to 60 ℃, preferably 30 ℃ to 50 ℃.

Compared with the prior art, the invention has at least the following beneficial effects:

the separation system and the separation method for the alkaline nitrides in the phenolic compounds provided by the invention utilize the synergistic effect between the first extracting agent for extracting the alkaline nitrides and the second extracting agent for extracting the phenolic compounds to extract and treat the phenolic products to be treated, so that the alkaline nitrides in the phenolic products can be transferred to the first extracting agent phase to obtain the second mixture, the phenolic compounds are transferred to the second extracting agent phase to obtain the first mixture, and the effective separation of the alkaline nitrides in the phenolic compounds is realized. And then distilling and separating the first mixture to obtain the phenolic compound, wherein the content of the basic nitride is obviously reduced, and the higher separation efficiency of the basic nitride in the phenolic product is realized. Meanwhile, the first mixture is distilled and separated to obtain the second extractant which can be recycled. And after the second mixture is subjected to back extraction treatment, separating to obtain a first extractant, and recycling the first extractant. Therefore, the method avoids the generation of waste water and waste liquid, and achieves excellent energy-saving and environment-friendly effects.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a system for separating basic nitrogen compounds from phenolic products according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of another system for separating basic nitrogen compounds from phenolic products according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a multistage centrifugal extraction unit according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of another system for separating basic nitrogen compounds from phenolic products according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantageous technical effects of the present invention more clear, the present invention is further described in detail with reference to the following embodiments. It should be understood that the embodiments described in this specification are only for the purpose of explaining the present invention and are not intended to limit the present invention.

For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and similarly any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.

In the description herein, it is to be noted that, unless otherwise specified, "above" and "below" are inclusive, and "a plurality" of "one or more" means two or more.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a list of embodiments that can be used in various combinations. In each instance, the list is merely a representative group and should not be construed as exhaustive.

First, a system for separating basic nitrogen compounds from a phenolic product according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Referring to fig. 1, a system for separating alkaline nitrides from phenolic products according to an embodiment of the present invention includes an extraction unit 10, a distillation separation unit 20, and a stripping unit 30.

The extraction unit 10 has a first outlet 11 and a second outlet 12. The extraction unit 10 is used for the extraction treatment of the phenolic product to be treated with a first extractant and a second extractant and delivers a first mixture comprising the second extractant and the phenolic compound from a first outlet 11 and a second mixture comprising the first extractant and the basic nitride from a second outlet 12.

The inlet 21 of the distillation separation unit 20 is connected to the first outlet 11 of the extraction unit 10. The distillation separation unit 20 has a third outlet 22 and a fourth outlet 23. The distillation separation unit 20 is configured to receive and distill the first mixture, and send the second extractant through a third outlet 22 and the phenolic compound through a fourth outlet 23.

The inlet 31 of the stripping unit 30 is connected to the second outlet 12 of the extraction unit 10. The stripping unit 30 has a fifth outlet 32 and a sixth outlet 33. The stripping unit 30 is for receiving and stripping the second mixture with a stripping agent and delivers the first extraction agent through a fifth outlet 32 and a third mixture containing the stripping agent and alkaline nitrides through a sixth outlet 33.

According to the separation system for the alkaline nitrides in the phenolic compounds, provided by the invention, the extraction unit 10 is used for extracting and treating the phenolic products to be treated by utilizing the synergistic effect between the first extracting agent for extracting the alkaline nitrides and the second extracting agent for extracting the phenolic compounds, so that the alkaline nitrides in the phenolic products are transferred to the first extracting agent phase to obtain the second mixture, and the phenolic compounds are transferred to the second extracting agent phase to obtain the first mixture, and the effective separation of the alkaline nitrides in the phenolic compounds is realized.

And then the first mixture is distilled and separated in a distillation separation unit 20 to obtain the phenolic compound, wherein the content of the basic nitride is obviously reduced, and the higher separation efficiency of the basic nitride in the phenolic product is realized. Meanwhile, the first mixture is distilled and separated to obtain the second extractant which can be recycled. And (3) separating the second mixture after the back extraction treatment in the back extraction unit 30 to obtain the first extractant, which can be recycled. Therefore, the method avoids the generation of waste water and waste liquid, and achieves excellent energy-saving and environment-friendly effects.

In addition, the invention has simple process and convenient operation.

In some embodiments, in extraction unit 10, the first extractant may comprise a ternary eutectic solvent synthesized from proline, choline chloride, and oxalic acid, and the second extractant employs a less polar solvent. The selection of the appropriate first extractant and second extractant can improve the separation efficiency of the system. In addition, the first extractant and the second extractant are mild in property, and equipment corrosion can be greatly reduced.

The ternary eutectic solvent can be prepared by taking proline, choline chloride and oxalic acid as raw materials and adopting a preparation method of the eutectic solvent known in the field. By way of example, proline, choline chloride and oxalic acid can be mixed at 80-100 ℃ to obtain a uniform and transparent liquid, namely a ternary eutectic solvent. The mixing treatment may be stirring mixing, ultrasonic mixing, or the like.

Of course, ternary eutectic solvents are also directly commercially available.

In some embodiments, preferably, the ternary eutectic solvent is synthesized from proline, choline chloride and oxalic acid in a molar ratio of 0.5-1: 1-3. For example, the ternary eutectic solvent is synthesized from proline, choline chloride and oxalic acid in a molar ratio of 1:1:1, 1:1:2, 1:1:3, 0.5:1:1, 0.5:1:2, 1:0.5:1 or 1:0.5: 2. The proportion of the proline, the choline chloride and the oxalic acid is proper, so that the separation efficiency of the alkaline nitride in the phenol products can be improved.

In some embodiments, the proline is one or more of L-proline, D-proline and DL-proline.

In some embodiments, the mass ratio of the ternary eutectic solvent to the phenolic product to be treated may be 2:1 to 1:10, preferably 1:1 to 1:10, more preferably 1:1 to 1:5, and more preferably 1:1 to 1: 2. The addition amount of the ternary eutectic solvent is proper, so that the separation efficiency of the alkaline nitride in the phenol product can be improved.

In some embodiments, the ternary eutectic solvent may be used directly as the first extractant in the extraction process of the phenolic product to be treated. Preferably, the first extractant is an aqueous solution of a ternary eutectic solvent. The aqueous solution of the ternary eutectic solvent can reduce the viscosity of the first extractant, so that the ternary eutectic solvent is more fully contacted with the phenol product to be treated, thereby improving the mass transfer efficiency in the extraction process and obtaining higher separation efficiency of the alkaline nitride. In addition, the use amount of the ternary eutectic solvent is favorably reduced.

Preferably, in the aqueous solution of the ternary eutectic solvent, the mass ratio of the ternary eutectic solvent to water is 5: 1-1: 5. The mass ratio of the ternary eutectic solvent to water in the aqueous solution of the ternary eutectic solvent is proper, so that the separation efficiency of the alkaline nitride in the phenolic product can be improved, and the water content in the phenolic compound obtained by separation is low.

Furthermore, in the aqueous solution of the ternary eutectic solvent, the mass ratio of the ternary eutectic solvent to water is 3: 1-1: 3, more preferably 2: 1-1: 2, such as 1: 1-1: 2.

In some embodiments, the second extractant may be selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether, and benzene. The second extractant can obtain higher separation effect of phenolic compounds and alkaline nitrides.

In some embodiments, the mass ratio of the second extractant to the phenolic product to be treated may be 10:1 to 1:2, such as 2:1 to 1: 1. The addition amount of the second extracting agent is proper, so that the separation efficiency of the alkaline nitrides in the phenol products can be improved.

In some embodiments, the temperature of the extraction process is preferably from 20 ℃ to 60 ℃. For example, the temperature of the extraction treatment may be 20 ℃ or more, 25 ℃ or more, 30 ℃ or more, 35 ℃ or more; and can be less than or equal to 60 ℃, less than or equal to 55 ℃, less than or equal to 50 ℃ and less than or equal to 45 ℃. More preferably, the temperature of the extraction treatment is between 30 ℃ and 50 ℃.

The temperature of extraction treatment is mild, and the energy consumption can be saved while the alkaline nitride in the phenol products can be efficiently separated.

Extraction unit 10 may employ extraction equipment known in the art. Referring to fig. 2, in some embodiments, the extraction unit 10 may include a centrifugal extraction apparatus 110. The centrifugal extraction device 110 has a first inlet (e.g., a light phase inlet) and a second inlet (e.g., a heavy phase inlet). The first extractant may enter the centrifugal extraction device 110 through the second inlet, and the second extractant and the phenolic product to be treated may enter the centrifugal extraction device 110 through the first inlet. The centrifugal extraction device 110 also has a first outlet 11 (e.g., a light phase outlet) and a second outlet 12 (e.g., a heavy phase outlet). That is, a first mixture containing the second extractant and the phenolic compound is sent out from the first outlet 11 of the centrifugal extraction device 110, and the first mixture enters the distillation separation unit 20 for distillation treatment; a second mixture of the first extractant and the alkaline nitride is sent out from the second outlet 12 of the centrifugal extraction device 110, and the second mixture enters the stripping unit 30 for stripping treatment.

The centrifugal extraction device 110 can more fully mix the first extractant and the second extractant with the phenol product to be treated, and can obtain higher mass transfer efficiency. Further, the centrifugal force is used for the separation by the centrifugal extraction device 110, and a high separation effect can be obtained. Therefore, the centrifugal extraction equipment 110 can obtain higher separation efficiency of the alkaline nitrides and higher yield of the phenolic products. In addition, the centrifugal extraction treatment can greatly improve the process efficiency.

The rotation speed of the centrifugal extraction device 110 and the time of centrifugal extraction can be determined by those skilled in the art according to the requirements of device specifications, separation efficiency, yield, etc.

In some embodiments, the rotational speed of the centrifugal extraction apparatus 110 may be between 100rpm and 3000 rpm. rpm, i.e. revolutions per minute, represents the number of revolutions per minute of the apparatus. For example, the rotation speed of the centrifugal extraction device 110 may be equal to or more than 100rpm, equal to or more than 500rpm, equal to or more than 1000rpm, equal to or more than 1500 rpm; and can be less than or equal to 2000rpm, less than or equal to 2500rpm, and less than or equal to 3000 rpm.

The centrifugal extraction apparatus 110 may employ a single-stage centrifugal extractor known in the art. And (3) feeding the first extractant, the second extractant and the phenolic product to be treated into a single-stage centrifugal extractor. In the single-stage centrifugal extractor, the first extractant and the second extractant are fully mixed with the phenol product to be treated for mass transfer, so that the alkaline nitride in the phenol product is transferred to the first extractant phase to obtain a second mixture, and the phenol compound is transferred to the second extractant phase to obtain a first mixture. Under the action of centrifugal force, the first mixture and the second mixture realize liquid-liquid two-phase separation due to different specific gravities and are respectively sent out from a light phase outlet and a heavy phase outlet of the single-stage centrifugal extractor.

In this context, a single stage centrifugal extractor may be used to perform a single stage extraction process on the phenolic product to be treated. Of course, a multistage centrifugal extraction unit with more than two single-stage centrifugal extractors connected in series can also be used. Referring to fig. 3, in the multi-stage centrifugal extractor set, the heavy phase outlet of the previous single-stage centrifugal extractor 111 may be connected to the heavy phase inlet of the next single-stage centrifugal extractor 111, and the light phase inlet of the previous single-stage centrifugal extractor 111 may be connected to the light phase outlet of the next single-stage centrifugal extractor 111. That is, the multi-stage centrifugal extraction unit realizes the high-efficiency separation of the alkaline nitride through the continuous countercurrent extraction of more than two stages, and improves the separation efficiency. Wherein the heavy phase may contain a first extractant and the light phase may contain a second extractant.

The centrifugal extractor 110 may also be a multi-stage centrifugal extractor known in the art, such as a two-stage centrifugal extractor, a three-stage centrifugal extractor, a four-stage centrifugal extractor, a five-stage centrifugal extractor, a six-stage centrifugal extractor, etc. And (3) feeding the first extractant, the second extractant and the phenolic product to be treated into a multistage centrifugal extractor. In the multistage centrifugal extractor, a first extracting agent and a second extracting agent are fully mixed with a phenol product to be treated for mass transfer, so that alkaline nitrides in the phenol product are transferred to the first extracting agent phase to obtain a second mixture, and a phenol compound is transferred to the second extracting agent phase to obtain a first mixture. Under the action of centrifugal force, the first mixture and the second mixture realize liquid-liquid two-phase separation due to different specific gravities and are respectively sent out from a light phase outlet and a heavy phase outlet of the multistage centrifugal extractor.

It is understood that there may be multiple centrifugal extractors in series in the centrifugal extraction apparatus 110. And the high-efficiency separation of the alkaline nitride is realized through more stages of continuous countercurrent extraction.

Referring to fig. 4, in some embodiments, the extraction unit 10 may include a stirring extraction apparatus 120. The agitated extraction device 120 can be a device known in the art for mixing, such as a heated stirred tank. The first extractant, the second extractant and the phenol product to be treated are fed into a stirring extraction device 120, and under the action of stirring, the first extractant, the second extractant and the phenol product to be treated are fully mixed for mass transfer, so that the alkaline nitride in the phenol product is transferred to the first extractant phase to obtain a second mixture, and the phenol compound is transferred to the second extractant phase to obtain a first mixture.

The stirring speed and time of the stirring extraction device 120 can be determined by those skilled in the art according to the requirements of the device specification, separation efficiency, yield, etc.

In some embodiments, the stirring speed may be 500r/min to 3000r/min, for example, 500rpm or more, 1000rpm or more, 1500rpm or more; and can be less than or equal to 2000rpm, less than or equal to 2500rpm, and less than or equal to 3000 rpm.

In some embodiments, the stirring time may be 20min to 60min, for example, 20min or more, 25min or more, 30min or more, 35min or more; and can be less than or equal to 60min, less than or equal to 55min, less than or equal to 50min and less than or equal to 45 min.

After the mixing mass transfer is finished, the heating stirring tank can stop stirring, so that the mixed solution is subjected to standing separation. The first mixture and the second mixture are layered due to the difference in density, and the first mixture is obtained from the upper layer and the second mixture is obtained from the lower layer. In this embodiment, the heating agitation tank 120 has a first outlet 11 and a second outlet 12, which send out the first mixture and the second mixture, respectively.

Alternatively, the extraction unit 10 may further comprise a liquid-liquid separation device 130. The inlet of the liquid-liquid separation device 130 is connected to the outlet of the stirring extraction device 120, and is used for performing liquid-liquid separation on the stirring extraction processing product. In this embodiment, the liquid-liquid separation device 130 has a first outlet 11 and a second outlet 12 for feeding out the first mixture and the second mixture, respectively.

The liquid-liquid separation device 130 may be a centrifuge or a still separation tank (e.g., a settling tank, etc.), or the like.

In some embodiments, the distillation separation unit 20 includes a distillation apparatus 210. The inlet of the distillation apparatus 210 is connected to the first outlet 11 for receiving the first mixture. The distillation apparatus 210 has the third outlet 22 and the fourth outlet 23 as described. The distillation device 210 distills the first mixture and delivers the second extractant via a third outlet 22 and the phenolic compound via a fourth outlet 23.

Distillation apparatus 210 may employ distillation apparatuses known in the art. For example, the distillation device can be a simple distillation device (such as a heating distillation still, a distillation tower and the like), a rectification device (such as a rectification tower and the like, and can be a packing rectification tower, a plate-type rectification tower and the like) or a flash device (such as a flash drum, a flash tower and the like). One skilled in the art can determine the relevant process parameters for the distillation process performed by the distillation apparatus 210 according to the composition of the first mixture and the operation principle of the distillation apparatus 210.

In some embodiments, the stripping unit 30 includes a stripping apparatus 310 and a stripper supply apparatus 320. The inlet 31 of the stripping apparatus 310 is connected to the second outlet 12 for receiving the second mixture. The feed to the stripping apparatus 310 is connected to the stripping agent supply 320 for receiving stripping agent from the stripping agent supply 320. The stripping apparatus 300 has the fifth outlet 32 and the sixth outlet 33 as described. The second mixture and the stripping agent are respectively fed into the stripping device 310, and the stripping agent is used for carrying out stripping treatment on the alkaline nitride in the second mixture to respectively obtain the first extracting agent and a third mixture containing the stripping agent and the alkaline nitride, and the first extracting agent and the third mixture are respectively fed out from the fifth outlet 32 and the sixth outlet 33. The stripping unit 30 effects separation of the alkaline nitride from the first extractant, thereby recovering the first extractant.

In some embodiments, the stripping agent may be selected from one or more of ethyl acetate, dichloromethane, carbon tetrachloride, diethyl ether, and benzene.

Further, the temperature of the back-extraction unit 30 for performing the back-extraction treatment may be 20 ℃ to 60 ℃, such as 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 50 ℃, 60 ℃ and the like.

In some embodiments, the stripping apparatus 310 can be an extraction apparatus known in the art. For example, the extraction column (may be a counter-current extraction column, a co-current extraction column, and may be a packed extraction column, a plate extraction column, or the like), a centrifugal extractor (may be a single-stage centrifugal extractor, a two-stage centrifugal extractor, a centrifugal extractor having three or more stages, or the like), or a stirred extractor (e.g., a heating stirred tank, or the like) may be used.

In some embodiments, the separation system for basic nitrogen compounds in the phenolic product further comprises a polishing separation unit 40. The inlet of the refining separation unit 40 is connected with the sixth outlet 33 of the stripping unit 30, and is used for receiving the third mixture from the stripping unit 30 and carrying out refining separation treatment on the third mixture. The polishing separation unit 40 has a seventh outlet 41 and an eighth outlet 42. The refining separation unit 40 is used for refining and separating the third mixture to obtain the stripping agent and the alkaline nitride respectively, and sending the stripping agent and the alkaline nitride out from the seventh outlet 41 and the eighth outlet 42 respectively. Thereby, the recovery and utilization of the stripping agent are realized.

In some embodiments, the polishing separation unit 40 includes a polishing apparatus 410. The inlet of the refining apparatus 410 is connected to the sixth outlet 33 of the stripping unit 30, and the refining apparatus 410 has a seventh outlet 41 and an eighth outlet 42. The refining apparatus 410 performs a refining separation process on the third mixture, and sends out the stripping agent and the alkaline nitride from the seventh outlet 41 and the eighth outlet 42, respectively.

Further, the seventh outlet 41 of the refining apparatus 410 may be connected to the stripping agent supply apparatus 320 to effect reuse of the stripping agent in the stripping apparatus 310.

Alternatively, the refining apparatus 410 may be an adsorption refining apparatus or a rectification refining apparatus (e.g., a rectification refining column), or the like.

If the refining equipment is adsorption refining equipment, those skilled in the art can select appropriate adsorbent and adsorption process parameters according to the composition and adsorption principle of the third mixture. The basic nitride is separated from the third mixture by the adsorption of the basic nitride by the adsorbent. The adsorbent is, for example, a molecular sieve. The alkaline nitride is more polar than the stripping agent and is selectively adsorbed on the surface of the molecular sieve to achieve separation. And then desorbing the mixture by heating or purging the mixture by inert gas to obtain the alkaline nitride and the regenerated adsorbent.

If the refining equipment is rectification refining equipment, such as a rectification tower, and the like, a person skilled in the art can determine the structural parameters and the rectification process parameters of the rectification tower according to the composition of the third mixture and the rectification principle.

In some embodiments, the system for separating basic nitrogen compounds from a phenolic product further comprises a first mixer 50 and a second mixer 60. The first mixer 50 is connected to a first inlet of the extraction unit 10. The second mixer 60 is connected to a second inlet of the extraction unit 10. The first mixer 50 is used for mixing the second extractant and the phenolic product to be treated, and the mixed material is sent to the extraction unit 10. The second mixer 60 is used for mixing the ternary eutectic solvent and water to obtain the first extractant, and sending the first extractant into the extraction unit 10. The extraction of the phenolic product to be treated is carried out in the extraction unit 10 with a first and a second extractant.

In these embodiments, the alkaline nitride separation efficiency of the system can be improved by the pre-mixing of the first mixer 50 and the second mixer 60.

The first mixer 50 may employ a mixing device known in the art. For example, the first mixer 50 may be a stirred tank, an ultrasonic mixer, a tube mixer, or the like.

The second mixer 60 may employ a mixing device known in the art. For example, the second mixer 60 may be a stirred tank, an ultrasonic mixer, a tube mixer, or the like.

In some embodiments, the third outlet 22 of the distillation separation unit 20 may be connected to the inlet of the first mixer 50 through a pipeline to recycle the second extractant sent from the distillation separation unit 20, thereby achieving the effect of saving energy.

In some embodiments, the fifth outlet 31 of the stripping unit 30 can be connected to the inlet of the second mixer 60 through a pipeline to recycle the first extractant sent by the stripping unit 30, thereby achieving the effect of saving energy.

The embodiment of the invention also provides a method for separating the alkaline nitride from the phenol product. The method comprises the following steps:

and S10, extracting the phenolic product to be treated by using a first extracting agent and a second extracting agent, and performing liquid-liquid separation to obtain a first mixture containing the second extracting agent and the phenolic compound and a second mixture containing the first extracting agent and the alkaline nitride, wherein the first extracting agent comprises a ternary eutectic solvent, the ternary eutectic solvent is synthesized from proline, choline chloride and oxalic acid, and the second extracting agent adopts a weak-polarity solvent.

S20, distilling and separating the first mixture to obtain a second extracting agent and a phenolic compound.

S30, carrying out back extraction treatment on the second mixture by using the weak polar solvent as a back extractant to obtain a first extractant and a third mixture containing the back extractant and the alkaline nitride.

According to the method provided by the embodiment of the invention, a first extracting agent and a second extracting agent are adopted for extracting the phenolic product to be treated, wherein the first extracting agent comprises a ternary eutectic solvent synthesized by proline, choline chloride and oxalic acid, and the second extracting agent adopts a weak polar solvent. In the extraction process, the mutual synergistic effect of the first extractant and the second extractant is fully exerted. The basic nitrogen compounds in the phenolic product to be treated are transferred to the first extractant phase to obtain a second mixture containing the first extractant and the basic nitrogen compounds, and the phenolic compounds are transferred to the second extractant phase to obtain a first mixture containing the second extractant and the phenolic compounds. The separation efficiency of the phenolic compound and the alkaline nitride is high, and the subsequent separation operation is convenient.

And then, the phenol compound is obtained through separation, the content of the basic nitride in the phenol compound is obviously reduced, and the higher separation efficiency of the basic nitride in the phenol product is realized. Meanwhile, the first extractant and the second extractant are obtained by separation and can be recycled. Therefore, the method avoids the generation of waste water and waste liquid, and achieves excellent energy-saving and environment-friendly effects. In addition, the first extractant and the second extractant adopted by the method are mild in property, so that the corrosion damage to equipment is greatly reduced.

The method for separating the basic nitride from the phenol product provided by the embodiment of the invention can be implemented by adopting the system for separating the basic nitride from the phenol product.

The technical features described in the separation system for basic nitrogen compounds in phenol products of the present invention can also be applied to the separation method for basic nitrogen compounds in phenol products of the present invention, and are not described herein again.

The separation system and the method can be suitable for the separation treatment of alkaline nitrides of various phenolic products containing alkaline nitrides. For example, the phenolic product may be a phenolic product obtained by processing a phenolic fraction obtained by distilling coal tar, a phenolic product containing basic nitrides obtained by treating phenolic wastewater, or the like. The phenol product may contain phenol, cresol, and the like. The cresol may include a cresol (e.g., o-cresol, m-cresol, p-cresol), a xylenol (e.g., 2, 3-xylenol, 2, 4-xylenol, 2, 5-xylenol, 2, 6-xylenol, 3, 4-xylenol, 3, 5-xylenol), a trimethylphenol (e.g., 2,3, 6-trimethylphenol, 2,4, 6-trimethylphenol), and the like. Basic nitrides are, for example, pyridine bases, amines (e.g. aromatic amines, aliphatic amines), quinolines and their homologs.