Treatment device for extracting crude phenol from phenol-containing distillate oil and realizing zero discharge of wastewater

Abstract

The utility model relates to a treatment device for extracting crude phenol from phenol-containing distillate oil and realizing zero discharge of wastewater, which comprises an alkali preparation tank, an extraction pipeline at the top of a crystallizer is connected with the alkali preparation tank, the alkali preparation tank is respectively connected with the upper part of an alkaline washing tower, the upper part of a regenerator and the upper part of an adsorption tower, and the lower part of the alkaline washing tower is connected with a phenol-containing distillate oil pipeline; the bottom of the alkaline tower is connected with the upper part of the stripping tower through a pipeline; the bottom of the stripping tower is connected with the decomposition tower through a pipeline; the decomposition tower is connected with the upper part of the extraction machine; an extraction pipeline at the top of the extraction machine is connected with the lower part of the regenerator; a bottom extraction pipeline of the regenerator is connected with the decomposition tower, a bottom extraction pipeline of the adsorption tower is connected with the upper part of the complexing tank, a regeneration outlet of the adsorption tower is connected with the decomposition tower, and the complexing tank is connected with the crystallizer. The device provided by the utility model can realize extraction of crude phenol from carbolic oil and zero discharge of wastewater, and thoroughly solves the environmental protection problem in the process of acid-base phenol extraction from coal tar.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of coal chemical industry, coal tar comprehensive utilization, especially to a kind of phenol-containing fraction oil extraction crude phenol and wastewater zero discharge treatment device. BACKGROUND

[0002] Coal tar is a kind of black or blackish-brown viscous liquid with pungent odor, which is a liquid product produced in the pyrolysis process of coal. Coal tar is an important raw material for coal chemical industry, with rich chemical composition and wide application. The coal tar industry should continue to develop and contribute to the economy and the environment. However, a large amount of pollutants such as waste gas, wastewater and waste residue are generated during the production of coal tar, which will have a certain impact on the environment and ecology. Therefore, effective environmental protection measures need to be taken during the production and use of coal tar to reduce the emission of pollutants and protect the environment and ecology.

[0003] Phenol is one of the important chemical raw materials. In recent years, with the development of downstream products of phenol, the demand for phenol is increasing year by year, and the domestic supply is not enough at present. It needs to be imported every year. In coal tar, 86% of phenol is mainly concentrated in phenol oil, naphthalene oil and washing oil fraction. With the extension of downstream industrial chain, the market demand for crude phenol is increasing year by year. At present, acid-base method is one of the main ways to extract crude phenol from coal tar, which has the advantages of high efficiency, high yield, fast reaction and low cost. However, the acid-base method for extracting phenol will produce salt-containing and phenol-containing wastewater, which will cause harm to the environment. CONTENT OF UTILITY MODEL

[0004] The utility model aims at solving the deficiency of prior art, and provides a kind of phenol-containing fraction oil extraction crude phenol and wastewater zero discharge treatment device.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A kind of phenol-containing fraction oil extraction crude phenol and wastewater zero discharge treatment device, including alkali washing tower, stripping column, decomposition tower, extractor, regenerator, adsorption tower, complex groove, alkali preparation groove and crystallizer;

[0007] The solid alkali supply pipeline is connected with the alkali preparation tank, the crystallizer top production pipeline is connected with the alkali preparation tank, the dilute alkali outlet of the alkali preparation tank is connected with the upper part of the alkali washing tower, the upper part of the regenerator and the upper part of the adsorption tower through pipelines respectively, the alkali washing tower lower part is connected with the phenol-containing fraction oil pipeline, the alkali washing tower bottom is connected with the upper part of the stripping tower through a pipeline, the stripping tower bottom is connected with the decomposition tower through a pipeline, the decomposition tower is connected with the acid material supply pipeline, the sodium salt solution outlet of the decomposition tower is connected with the upper part of the extractor through a pipeline, the extractor lower part is connected with the extractant supply pipeline, the extractor top production pipeline is connected with the lower part of the regenerator, the extractor bottom production pipeline is connected with the top of the adsorption tower, the regenerator top production pipeline is connected with the extractant supply pipeline, the regenerator bottom production pipeline is connected with the decomposition tower, the adsorption tower bottom production pipeline is connected with the upper part of the complexing tank, the adsorption tower regeneration outlet is connected with the decomposition tower, the complexing tank is connected with the complexing agent pipeline, and the complexing tank is connected with the crystallizer.

[0008] The alkali washing tower is single operation or multi-stage series operation, and the number of stages of the alkali washing tower is 1-6.

[0009] The extractor is single operation or multi-stage series operation, and the number of stages of the extractor is 1-6; when the extractor is single operation, the extractor is any one of a tower, a stirring tank and a centrifuge; when the extractor is multi-stage series operation, the extractor is any one of a tower, a stirring tank and a centrifuge in single series or any combination of a tower, a stirring tank and a centrifuge.

[0010] The regenerator is single operation or multi-stage series operation, and the number of stages of the regenerator is 1-6; when the regenerator is single operation, the regenerator is any one of a tower, a stirring tank and a centrifuge; when the regenerator is multi-stage series operation, the regenerator is any one of a tower, a stirring tank and a centrifuge in single series or any combination of a tower, a stirring tank and a centrifuge.

[0011] The utility model discloses the beneficial effect is: the utility model can realize phenol oil extraction crude phenol and wastewater zero discharge, completely solved the environmental protection problem of coal tar acid alkali phenol extraction process. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is the connection diagram of the processing device in the utility model;

[0013] In the drawing: 1-alkali washing tower;2-stripping tower;3-decomposition tower;4-extractor;5-regenerator;6-adsorption tower;7-complexing tank;8-alkali preparation tank;9-crystallizer;10-solid alkali supply pipeline;11-phenol-containing fraction oil pipeline;12-acid material supply pipeline;13-extractant supply pipeline;14-complexing agent pipeline;

[0014] The utility model will be described in detail below in combination with the embodiment of the utility model and with reference to the drawings. DETAILED DESCRIPTION

[0015] The principles and features of this utility model are described below with reference to the accompanying drawings. The embodiments described are for illustrative purposes only and are not intended to limit the scope of this utility model. The utility model is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] A device for extracting crude phenol from phenolic distillate oil and treating wastewater with zero discharge, such as Figure 1 As shown, it includes an alkali washing tower 1, a stripping tower 2, a decomposition tower 3, an extractor 4, a regenerator 5, an adsorption tower 6, a complexing tank 7, an alkali mixing tank 8, and a crystallizer 9.

[0019] The alkali mixing tank 8 is connected to a solid alkali supply pipeline 10. The top outlet pipeline of the crystallizer 9 is connected to the alkali mixing tank 8. The dilute alkali outlet of the alkali mixing tank 8 is connected to the upper part of the alkali washing tower 1, the upper part of the regenerator 5, and the upper part of the adsorption tower 6 via pipelines. The lower part of the alkali washing tower 1 is connected to a phenol-containing distillate oil pipeline 11. The bottom of the alkali washing tower 1 is connected to the upper part of the stripping tower 2 via a pipeline. The bottom of the stripping tower 2 is connected to the decomposition tower 3 via a pipeline. The decomposition tower 3 is connected to an acidic substance supply pipeline 12. The sodium salt solution outlet of the decomposition tower 3 is connected to the extractor via a pipeline. 4. The upper part of the extractor 4 is connected to the extractant supply pipeline 13 at the lower part. The top outlet pipeline of the extractor 4 is connected to the lower part of the regenerator 5. The bottom outlet pipeline of the extractor 4 is connected to the top of the adsorption tower 6. The top outlet pipeline of the regenerator 5 is connected to the extractant supply pipeline 13. The bottom outlet pipeline of the regenerator 5 is connected to the decomposition tower 3. The bottom outlet pipeline of the adsorption tower 6 is connected to the upper part of the complexing tank 7. The regeneration outlet of the adsorption tower 6 is connected to the decomposition tower 3. The complexing tank 7 is connected to the complexing agent pipeline 14. The complexing tank 7 is connected to the crystallizer 9.

[0020] The alkali washing tower 1 is operated in single or multiple stages, and the number of stages of the alkali washing tower 1 is 1-6. When the alkali washing tower 1 is operated in multiple stages, the dilute alkali is introduced from the upper part of the first tower and the phenol-containing distillate oil is introduced from the lower part of the last tower, and the two are countercurrently contacted, and finally the dephenolized oil is collected at the top of the first tower and the sodium phenolate solution is collected at the bottom of the last tower.

[0021] The extractor 4 is operated in single or multiple stages, and the number of stages of the extractor 4 is 1-6. When the extractor 4 is operated in single stage, the extractor 4 is any one of a tower, a stirring tank and a centrifuge. When the extractor 4 is operated in multiple stages, the extractor 4 is any one of a tower, a stirring tank and a centrifuge operated in single stage or any combination of a tower, a stirring tank and a centrifuge.

[0022] The regenerator 5 is operated in single or multiple stages, and the number of stages of the regenerator 5 is 1-6. When the regenerator 5 is operated in single stage, the regenerator 5 is any one of a tower, a stirring tank and a centrifuge. When the regenerator 5 is operated in multiple stages, the regenerator 5 is any one of a tower, a stirring tank and a centrifuge operated in single stage or any combination of a tower, a stirring tank and a centrifuge.

[0023] A method for extracting crude phenol from phenol-containing distillate oil and zero discharge of waste water, which uses the device for extracting crude phenol from phenol-containing distillate oil and zero discharge of waste water, and the specific steps are as follows:

[0024] S1, dilute alkali preparation:

[0025] The dilute alkali is prepared by mixing the desalination waste water from the subsequent crystallizer 9 and solid alkali in the alkali preparation tank 8, and the concentration of the dilute alkali is 2%-50%, the operating temperature in the alkali preparation tank 8 is 25℃-100℃, and the pressure is 0MPa(g)-0.6MPa(g).

[0026] The dilute alkali is used as a raw material for phenol oil alkali washing, extraction agent regeneration and adsorption regeneration.

[0027] S2, phenol oil alkali washing:

[0028] The phenol-containing distillate oil is introduced into the tower from the lower part of the alkali washing tower 1 and countercurrently contacted with the dilute alkali introduced from the upper part of the alkali washing tower 1, the volume ratio of the dilute washing to the phenol-containing distillate oil is 1:100, the operating temperature is 25℃-100℃, the operating pressure is 0MPa(g)-0.6MPa(g), the phenol-containing distillate oil is composed of phenol oil and neutral oil, the phenol oil reacts with the dilute alkali to generate a sodium phenolate solution, the remaining distillate is dephenolized oil, the sodium phenolate solution is heavier than the dephenolized oil and is insoluble in the dephenolized oil, so that the dephenolized oil is collected at the top of the alkali washing tower 1 and sold as a byproduct, and the sodium phenolate solution is collected at the bottom of the alkali washing tower 1 and used as a raw material for crude phenol production.

[0029] S3, stripping and impurity removal:

[0030] The phenol sodium salt solution enters from the upper part of the stripping tower 2, the stripping tower 2 is heated indirectly or directly, the operating temperature is 100℃-180℃, the operating pressure is 0MPa(g)-0.6MPa(g), the phenol sodium salt solution contains a small amount of neutral oil, the neutral oil impurities are removed by stripping to obtain a pure phenol sodium salt solution without neutral oil impurities, the neutral oil is gasified in the tower bottom and rises to the top of the tower, the liquid phase neutral oil is collected after condensation and cooling at the top of the tower, the neutral oil is sold as a byproduct; the pure phenol sodium salt solution without neutral oil is collected from the tower bottom, and the pure phenol sodium salt solution is sent to the decomposition tower 3 after temperature reduction by a cooler.

[0031] S4, acidification and decomposition:

[0032] The phenol sodium salt can react with substances that are more acidic than phenol, and an acid substance that is more acidic than phenol is added to the decomposition tower 3, the phenol sodium salt reacts with the acid substance, the concentration of the acid substance is 10%-100%, the volume ratio of the acid substance to the phenol sodium salt solution is 1:1000, the operating temperature is 100℃-180℃, and the operating pressure is 0MPa(g)-0.6MPa(g), after the reaction is completed, crude phenol and a sodium salt solution (sodium carbonate or sodium sulfate) are produced, because the crude phenol is relatively small and the crude phenol is insoluble in the sodium salt solution, the crude phenol and the sodium salt solution are separated into two layers, the upper layer is crude phenol and the lower layer is a sodium salt solution, the crude phenol is sold as a product, and the sodium salt solution contains a small amount of phenolic substances, the sodium salt solution is extracted by an extractor 4 to remove phenol;

[0033] The acid substance is carbon dioxide, sulfuric acid, or a combination of carbon dioxide and sulfuric acid in any proportion.

[0034] S5, extraction and phenol removal:

[0035] The sodium salt solution contains a small amount of phenolic compounds and needs to be treated to remove phenol, the sodium salt solution enters from the upper part of the extractor 4 and is in countercurrent contact with the extractant entering from the lower part of the extractor 4, the volume ratio of the extractant to the sodium salt solution is 1:100, the operating temperature is 100℃-180℃, and the operating pressure is 0MPa(g)-0.6MPa(g), the phenol-containing extractant is collected at the top of the extractor 4, the phenol-containing extractant is used as the feed of the regenerator 5, and the extraction and phenol removal wastewater is collected at the bottom of the extractor 4 and used as the feed of the adsorption tower 6;

[0036] The extractant is one or a combination of any number of toluene, xylene, methyl isobutyl ketone, methyl tert-butyl ketone, diisopropyl ether, methyl tert-amyl ether, butyl acetate, sec-butyl acetate, dimethyl carbonate, 2-ethylhexyl phosphate-2-ethylhexyl ester, methyldiethanolamine, N,N-bis(1-methylheptyl)acetamide, dihexylpropanolamine, cyclobutane sulfone, and petroleum ether.

[0037] S6, extractant regeneration:

[0038] The phenol-containing extractant enters from the lower part of the regenerator 5 and is countercurrently contacted with the dilute alkali entering from the upper part of the regenerator 5, the volume ratio of the dilute alkali to the phenol-containing fraction oil is 1:100, the operating temperature is 25-100℃, the operating pressure is 0-0.6MPa(g), the extractant is collected at the top of the regenerator 5 and is recycled to the extractor 4, and the sodium phenolate solution is collected at the bottom of the regenerator 5 and is used as the feed of the acidification and decomposition, and is sent to the decomposition tower 3;

[0039] S7, adsorption and dephenolization:

[0040] The extractive dephenolization wastewater enters from the top of the adsorption tower 6, the adsorption tower 6 is filled with adsorption filler, the extractive dephenolization wastewater passes through the adsorption filler, the phenolic substances in the wastewater are adsorbed by the adsorption filler, the adsorptive dephenolization wastewater is collected at the bottom of the adsorption tower 6 and is used as the feed of the complexing tank 7, when the adsorption filler is saturated, dilute alkali is introduced into the adsorption tower 6, the dilute alkali reacts with the phenol on the surface of the adsorption filler to produce sodium phenolate solution, the sodium phenolate solution is collected at the bottom of the adsorption column and is sent to the decomposition tower 3, after the sodium phenolate is discharged, the regeneration of the adsorption tower is completed, and the regenerated adsorption column is recycled, the operating temperature is 25-100℃, and the operating pressure is 0-0.6MPa(g);

[0041] The adsorption filler is one or any combination of activated carbon, resin, coke, semi-coke and membrane.

[0042] S8, complexing and impurity removal:

[0043] The adsorptive dephenolization wastewater contains developing ions and molecules, the adsorptive dephenolization wastewater enters from the upper part of the complexing tank 7, a complexing agent is added into the complexing tank 7, the complexing agent is a dilute solution with a concentration of 0.1%-30%, the mass ratio of the complexing agent to the adsorptive dephenolization wastewater is 1:1000, the operating temperature is 25-100℃, and the operating pressure is 0-0.6MPa(g), the developing substances in the adsorptive dephenolization wastewater are complexed with the complexing agent to form a precipitate, the complexing precipitate is separated from the bottom of the complexing tank 7, and the decolorized wastewater is obtained, and the decolorized wastewater is used as the feed of the crystallizer 9;

[0044] The complexing agent is any one or a combination of compounds containing sodium ions, calcium ions or molecules, magnesium ions or molecules, copper ions or molecules, iron ions or molecules, aluminum ions or molecules, zinc ions or molecules, thiosulfate, carbonate, sulfate, hydroxyl and carbon chain groups.

[0045] S9, crystallization and desalination:

[0046] The decolorized wastewater is sent to a crystallizer 9, the crystallizer 9 is used for desalination by heating or freezing, the operation temperature of the crystallization desalination is -25 DEG C-200 DEG C, the operation pressure is -0.1 MPa(g)-0.6 MPa(g), the crystallization desalination includes one or any combination of single-effect evaporation, multi-effect evaporation, MVR and freezing crystallization, finally, inorganic salts are obtained at the bottom of the crystallizer 9, and device circulating water is obtained at the top of the crystallizer 9, the device circulating water is low-concentration wastewater, the device circulating water returns to the alkali preparation tank 8 and is used as raw material for preparing dilute alkali, and zero discharge of wastewater in the whole process is realized.

[0047] The utility model can realize phenol oil extraction of crude phenol and wastewater zero discharge, and completely solve the environmental protection problem of coal tar acid-base phenol extraction process.

[0048] The utility model has been described above in conjunction with the drawings, and obviously, the specific implementation of the utility model is not limited by the above mode, as long as various improvements are made by adopting the method concept and technical scheme of the utility model, or the utility model is directly applied to other occasions without improvement, and all falls within the protection scope of the utility model.

Claims

1. A device for extracting crude phenol from phenol-containing distillate oil and treating wastewater with zero discharge, characterized in that, It includes an alkali washing tower (1), a stripping tower (2), a decomposition tower (3), an extractor (4), a regenerator (5), an adsorption tower (6), a complexing tank (7), an alkali mixing tank (8), and a crystallizer (9); The alkali mixing tank (8) is connected to a solid alkali supply pipeline (10). The top outlet pipeline of the crystallizer (9) is connected to the alkali mixing tank (8). The dilute alkali outlet of the alkali mixing tank (8) is connected to the upper part of the alkali washing tower (1), the upper part of the regenerator (5), and the upper part of the adsorption tower (6) via pipelines. The lower part of the alkali washing tower (1) is connected to a phenol-containing distillate oil pipeline (11). The bottom of the alkali washing tower (1) is connected to the upper part of the stripping tower (2) via a pipeline. The bottom of the stripping tower (2) is connected to the decomposition tower (3) via a pipeline. The decomposition tower (3) is connected to an acidic substance supply pipeline (12). The sodium salt solution outlet of the decomposition tower (3) is connected to the extractor (4) via a pipeline. The upper part is connected to the extractor (4), the lower part is connected to the extractant supply line (13), the top outlet line of the extractor (4) is connected to the lower part of the regenerator (5), the bottom outlet line of the extractor (4) is connected to the top of the adsorption tower (6), the top outlet line of the regenerator (5) is connected to the extractant supply line (13), the bottom outlet line of the regenerator (5) is connected to the decomposition tower (3), the bottom outlet line of the adsorption tower (6) is connected to the upper part of the complexing tank (7), the regeneration outlet of the adsorption tower (6) is connected to the decomposition tower (3), the complexing tank (7) is connected to the complexing agent line (14), and the complexing tank (7) is connected to the crystallizer (9).

2. The apparatus for extracting crude phenol from phenol-containing distillate oil and treating wastewater with zero discharge according to claim 1, characterized in that, The alkaline scrubbing tower (1) can be operated as a single unit or in cascade mode, and the number of stages of the alkaline scrubbing tower (1) is 1-6.

3. The apparatus for extracting crude phenol from phenol-containing distillate oil and treating wastewater with zero discharge according to claim 1, characterized in that, The extractor (4) can be operated as a single unit or as multiple units in cascade, and the number of stages of the extractor (4) is 1-6. When the extractor (4) is operated as a single unit, the extractor (4) can be any one of the following: tower, stirred tank, or centrifuge. When the extractor (4) is operated as multiple units in cascade, the extractor (4) can be any one of the following: tower, stirred tank, or centrifuge, either individually in cascade or in any combination of tower, stirred tank, and centrifuge.

4. The apparatus for extracting crude phenol from phenol-containing distillate oil and treating wastewater with zero discharge according to claim 1, characterized in that, The regenerator (5) can be operated as a single unit or in cascade mode, and the number of stages of the regenerator (5) is 1-6. When the regenerator (5) is operated as a single unit, the regenerator (5) can be any one of the following: tower, mixing tank, or centrifuge. When the regenerator (5) is operated in cascade mode, the regenerator (5) can be any one of the following: tower, mixing tank, or centrifuge, either individually in cascade or in any combination of tower, mixing tank, and centrifuge.

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