CN211170278U - Coal chemical wastewater extraction dephenolization resourceful treatment system - Google Patents

Abstract

The utility model discloses a resource treatment system for extracting and dephenolizing coal chemical wastewater, which comprises an oil removal unit, an extraction dephenolizing unit and an ammonia distillation unit which are connected in sequence; the extraction dephenolization unit and the ammonia distillation unit are also respectively connected with the primary heat exchange unit; the first-stage heat exchange unit is connected with the pervaporation unit, and the pervaporation unit is connected with the second-stage heat exchange unit; the primary heat exchange unit is also connected with the secondary heat exchange unit; the system realizes effective separation of the extracting agent and the phenolic compounds by adding the pervaporation unit, not only reduces the loss of the extracting agent, but also has high purity of the recovered phenol product, and the extracting agent can be directly recycled.

Description

Coal chemical wastewater extraction dephenolization resourceful treatment system

Technical Field

The invention belongs to the field of wastewater treatment, and particularly relates to a coal chemical wastewater extraction dephenolization recycling treatment system.

Background

With the rapid development of the coal chemical industry, the discharge amount of waste water is increasing day by day, wherein the phenol-containing waste water has great harm, phenol and other phenol compounds can cause skin allergy, anemia and various nervous system diseases of human bodies, and the animal and plant death and the serious damage to the ecological environment can be caused by the random discharge of phenol and other phenol compounds.

The existing phenol-containing wastewater treatment method mainly comprises an adsorption method, a steam method, an extraction method and the like, and the extraction method has the advantages of low energy consumption, convenience in recycling and reutilization and the like, so that the method is widely applied, but has the defects of easy solvent loss and large solvent consumption; the extractant recovery mostly adopts alkali liquor for back extraction, which not only increases the solvent loss, but also has complex process flow and is not beneficial to the final recovery of the phenolic compounds.

CN103964543B discloses a method for removing oil and phenol from wastewater in the field of coal chemical industry, which comprises the procedures of wastewater pretreatment, extraction oil removal and phenol removal and extraction agent recovery, thereby achieving good oil removal and phenol removal effects, but the extraction agent recovery method is an alkaline washing method, wherein two items are easily mixed, the loss of the extraction agent is increased, and the concentration of the obtained sodium phenolate solution is low.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a coal chemical wastewater extraction dephenolization resourceful treatment system, this system have realized the direct separation of extractant and phenolic compound through pervaporation technology and have retrieved on prior art basis, not only reduce the extractant loss, and the phenol product purity through pervaporation is high moreover, and process flow is simple.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a coal chemical industry wastewater extraction dephenolization resource treatment system comprises an oil removal unit, an extraction dephenolization unit and an ammonia distillation unit which are sequentially connected; the extraction dephenolization unit and the ammonia distillation unit are also respectively connected with the primary heat exchange unit; the first-stage heat exchange unit is connected with the pervaporation unit, and the pervaporation unit is connected with the second-stage heat exchange unit; the first-stage heat exchange unit is also connected with the second-stage heat exchange unit

The secondary heat exchange unit is also connected with the extraction dephenolization unit.

The oil removing unit comprises gravity oil removing and air floatation oil removing;

the gravity oil removal is preferably any one of an oil separation tank, an oil separation well, an oil removal tank and coarse grained oil removal;

the air flotation oil removal is preferably any one of full-flow pressurized dissolved air flotation, partial pressurized dissolved air flotation or partial reflux pressurized dissolved air flotation;

the oil removal rate of the wastewater after oil removal treatment is more than or equal to 80 percent.

The extraction dephenolization unit preferably adopts any one of a filler extraction tower, a sieve plate extraction tower, a rotary disc extraction tower, a vibrating sieve plate tower or a multi-stage centrifugal extraction tower;

the extractant is preferably at least one of methyl isobutyl ketone, ethyl acetate, benzene or diisopropyl ether; the volume ratio of the extracting agent to the water is 1: 20-1: 1; the extraction temperature is preferably 30-50 ℃; after extraction dephenolization treatment, the removal rate of the phenolic compounds is more than or equal to 95 percent.

The ammonia distillation unit is preferably any one of direct ammonia distillation or indirect ammonia distillation; the outlet water temperature of the ammonia distillation unit is 100-110 ℃; the ammonia nitrogen removal rate of the ammonia distillation treatment is more than or equal to 95 percent.

The primary heat exchange unit is preferably a heat exchanger; the heat exchanger is preferably any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger; the temperature of the extraction liquid outlet after heat exchange is 30-80 ℃, and the ammonia distillation wastewater enters a secondary heat exchange unit for treatment.

The pervaporation unit adopts a vacuum pumping method, and the pervaporation membrane is preferably a hydrophilic composite flat membrane; the pervaporation operation temperature is preferably 30-80 ℃; the separation factor of the finally recovered extractant is more than or equal to 15, and the recovery rate is more than or equal to 90%.

The secondary heat exchange unit is preferably a heat exchanger; the heat exchanger is preferably any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger; the outlet temperature of the extract liquid after heat exchange is 30-50 DEG C

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the utility model discloses a coal chemical wastewater extraction dephenolization resourceful treatment system, which realizes the effective separation of an extracting agent and a phenolic compound by adding a pervaporation unit, not only reduces the loss of the extracting agent, but also has high purity of the recovered phenol product, and the extracting agent can be directly reused;

2. condensed water discharged by the ammonia evaporation unit exchanges heat with inlet and outlet water of the pervaporation unit to heat, so that the heating cost is greatly saved, the work efficiency of pervaporation treatment is enhanced, and the temperature of ammonia evaporation wastewater is reduced to be beneficial to subsequent advanced treatment such as biochemistry and the like, thereby improving the stability of the system.

Drawings

FIG. 1 is a diagram of the apparatus connection of the treatment system of the present invention.

In the figure: 1-an oil removal unit; 2-an extraction dephenolization unit; 3-an ammonia distillation unit; 4-a first-stage heat exchange unit; 5-a pervaporation unit; 6-secondary heat exchange unit.

Detailed Description

In order to better explain the present invention and facilitate understanding of the technical solutions of the present invention, the present invention is further explained in detail below. The following embodiments are merely exemplary of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.

As shown in fig. 1, a coal chemical wastewater extraction dephenolization resource treatment system comprises an oil removal unit 1, an extraction dephenolization unit 2 and an ammonia distillation unit 3 which are connected in sequence; the extraction dephenolization unit 2 and the ammonia distillation unit 3 are also respectively connected with a primary heat exchange unit 4; the primary heat exchange unit 4 is connected with the pervaporation unit 5, and the pervaporation unit 5 is connected with the secondary heat exchange unit 6; the primary heat exchange unit 4 is also connected with the secondary heat exchange unit 6, and the secondary heat exchange unit 6 is also connected with the extraction dephenolization unit 2.

The oil removing unit 1 comprises gravity oil removing and air floatation oil removing; the gravity oil removal is preferably any one of an oil separation tank, an oil separation well, an oil removal tank and coarse grained oil removal; the air flotation oil removal is preferably any one of full-flow pressurized dissolved air flotation, partial pressurized dissolved air flotation or partial reflux pressurized dissolved air flotation; the oil removal rate of the wastewater after oil removal treatment is more than or equal to 80 percent.

The extraction dephenolization unit 2 preferably adopts any one of a filler extraction tower, a sieve plate extraction tower, a rotary disc extraction tower, a vibrating sieve plate tower or a multi-stage centrifugal extraction tower; the extractant is preferably at least one of methyl isobutyl ketone, ethyl acetate, benzene or diisopropyl ether; the volume ratio of the extracting agent to the water is 1: 20-1: 1, 1:20, 1:19, 1:18, 1:17, 1:16, 1:15, 1:14, 1:13, 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1: 1; the extraction temperature is preferably 30-50 deg.C, 30 deg.C, 31 deg.C, 32 deg.C, 33 deg.C, 34 deg.C, 35 deg.C, 36 deg.C, 37 deg.C, 38 deg.C, 39 deg.C, 40 deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.

The ammonia distillation unit 3 is preferably any one of direct ammonia distillation and indirect ammonia distillation; the temperature of the effluent of the ammonia distillation unit is 110 ℃ at 100 ℃, 101 ℃, 102 ℃, 103 ℃, 104 ℃, 105 ℃, 106 ℃, 107 ℃, 108 ℃, 109 ℃ and 110 ℃; the ammonia nitrogen removal rate of the ammonia distillation treatment is more than or equal to 95 percent.

The primary heat exchange unit 4 is preferably a heat exchanger; the heat exchanger is preferably any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger; the outlet temperature of the heat-exchanged extract is 30-80 ℃, 30 ℃, 31 ℃, 32 ℃, 33 ℃, 34 ℃, 35 ℃, 36 ℃, 37 ℃, 38 ℃, 39 ℃, 40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃, 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃, 50 ℃, 51 ℃, 52 ℃, 53 ℃, 54 ℃, 55 ℃, 56 ℃, 57 ℃, 58 ℃, 59 ℃, 60 ℃, 61 ℃, 62 ℃, 63 ℃, 64 ℃, 65 ℃, 66 ℃, 67 ℃, 68 ℃, 69 ℃, 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃, 79 ℃ and 80 ℃, and the ammonia-evaporated wastewater enters the secondary heat exchange unit 6 for treatment.

The pervaporation unit 5 adopts a vacuum pumping method, and the pervaporation membrane is preferably a hydrophilic composite flat membrane; the pervaporation operation temperature is preferably 30-80 deg.C, 30 deg.C, 31 deg.C, 32 deg.C, 33 deg.C, 34 deg.C, 35 deg.C, 36 deg.C, 37 deg.C, 38 deg.C, 39 deg.C, 40 deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.C, 51 deg.C, 52 deg.C, 53 deg.C, 54 deg.C, 55 deg.C, 56 deg.C, 57 deg.C, 58 deg.C, 60 deg.C, 61 deg.C, 62 deg.C, 63 deg.

The secondary heat exchange unit 6 is preferably a heat exchanger; the heat exchanger is preferably any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger; the outlet temperature of the heat-exchanged extract is 30-50 deg.C, 30 deg.C, 31 deg.C, 32 deg.C, 33 deg.C, 34 deg.C, 35 deg.C, 36 deg.C, 37 deg.C, 38 deg.C, 39 deg.C, 40 deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.

Example 1

The oil content of wastewater of a certain coal chemical industry plant is 100 mg/L, the phenol content is 3000 mg/L, and the ammonia nitrogen content is 2000 mg/L, and the method is adopted for treatment as follows:

pretreating coal chemical wastewater and then carrying out oil removal treatment, wherein the oil removal technology comprises gravity oil removal and air flotation oil removal technology, the gravity removal is an oil separation tank, the air flotation oil removal is full-flow pressurized dissolved air flotation, and the oil content of effluent of an oil removal unit is 8 mg/L;

carrying out extraction dephenolization treatment on the coal chemical industry wastewater treated in the step (1), wherein an extraction dephenolization device is a sieve plate extraction tower, an extracting agent is methyl isobutyl ketone, the volume ratio of the extracting agent to water is 1:10, the extraction temperature is 45 ℃, and the content of phenol in effluent after extraction is 120 mg/L;

performing ammonia distillation treatment on the wastewater treated in the step (2), wherein the ammonia distillation technology is direct ammonia distillation, the effluent temperature of an ammonia distillation unit is 105 ℃, and the ammonia nitrogen content of the effluent of the ammonia distillation is 80 mg/L;

performing heat exchange treatment on the extract liquor in the step (2) and the wastewater treated in the step (3), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extract liquor is 80 ℃, and performing secondary heat exchange treatment on the wastewater after heat exchange;

carrying out pervaporation treatment on the extract liquor heated in the step (4), wherein the pervaporation adopts a vacuum pumping method, the pervaporation membrane is a hydrophilic composite flat membrane, the operating temperature is 80 ℃, the separating factor of the extracting agent is about 20, and the recovery rate is about 98%;

and (3) carrying out secondary heat exchange treatment on the extractant separated in the step (5) and the wastewater subjected to heat exchange in the step (4), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extractant is 30 ℃, the extractant is further preheated to 45 ℃ by steam, the extractant returns to the extraction unit, and the ammonia distillation effluent subjected to secondary heat exchange is further subjected to biochemical treatment.

Example 2

The method comprises the following steps of treating the wastewater of a coal chemical industry plant with the oil content of 50 mg/L, the phenol content of 2000 mg/L and the ammonia nitrogen content of 2000 mg/L by the following method:

pretreating coal chemical wastewater and then carrying out oil removal treatment, wherein the oil removal technology comprises gravity oil removal and air flotation oil removal technology, the gravity removal is an oil separation tank, the air flotation oil removal is full-flow pressurized dissolved air flotation, and the oil content of effluent of an oil removal unit is 6 mg/L;

carrying out extraction dephenolization treatment on the coal chemical industry wastewater treated in the step (1), wherein an extraction dephenolization device is a sieve plate extraction tower, an extracting agent is methyl isobutyl ketone, the volume ratio of the extracting agent to water is 1:10, the extraction temperature is 45 ℃, and the phenol content of the extracted effluent is 80 mg/L;

performing ammonia distillation treatment on the wastewater treated in the step (2), wherein the ammonia distillation technology is direct ammonia distillation, the effluent temperature of an ammonia distillation unit is 105 ℃, and the ammonia nitrogen content of the effluent of the ammonia distillation is 80 mg/L;

performing heat exchange treatment on the extract liquor in the step (2) and the wastewater treated in the step (3), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extract liquor is 80 ℃, and performing secondary heat exchange treatment on the wastewater after heat exchange;

carrying out pervaporation treatment on the extract liquor heated in the step (4), wherein the pervaporation adopts a vacuum pumping method, the pervaporation membrane is a hydrophilic composite flat membrane, the operating temperature is 80 ℃, the separating factor of the extracting agent is about 20, and the recovery rate is about 98%;

and (3) carrying out secondary heat exchange treatment on the extractant separated in the step (5) and the wastewater subjected to heat exchange in the step (4), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extractant is 30 ℃, the extractant is further preheated to 45 ℃ by steam, the extractant returns to the extraction unit, and the ammonia distillation effluent subjected to secondary heat exchange is further subjected to biochemical treatment.

Example 3

The oil content of wastewater of a certain coal chemical industry plant is 150 mg/L, the phenol content is 5000 mg/L, and the ammonia nitrogen content is 3000 mg/L, and the method is adopted for treatment as follows:

pretreating coal chemical wastewater and then carrying out oil removal treatment, wherein the oil removal technology comprises gravity oil removal and air flotation oil removal technology, the gravity removal is an oil separation tank, the air flotation oil removal is full-flow pressurized dissolved air flotation, and the oil content of effluent of an oil removal unit is 10 mg/L;

carrying out extraction dephenolization treatment on the coal chemical industry wastewater treated in the step (1), wherein an extraction dephenolization device is a sieve plate extraction tower, an extracting agent is methyl isobutyl ketone, the volume ratio of the extracting agent to water is 1:15, the extraction temperature is 45 ℃, and the content of phenol in effluent after extraction is 180 mg/L;

performing ammonia distillation treatment on the wastewater treated in the step (2), wherein the ammonia distillation technology is direct ammonia distillation, the effluent temperature of an ammonia distillation unit is 105 ℃, and the ammonia nitrogen content of the effluent of the ammonia distillation is 200 mg/L;

performing heat exchange treatment on the extract liquor in the step (2) and the wastewater treated in the step (3), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extract liquor is 80 ℃, and performing secondary heat exchange treatment on the wastewater after heat exchange;

carrying out pervaporation treatment on the extract liquor heated in the step (4), wherein the pervaporation adopts a vacuum pumping method, the pervaporation membrane is a hydrophilic composite flat membrane, the operating temperature is 80 ℃, the separating factor of the extracting agent is about 20, and the recovery rate is about 98%;

and (3) carrying out secondary heat exchange treatment on the extractant separated in the step (5) and the wastewater subjected to heat exchange in the step (4), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extractant is 30 ℃, the extractant is further preheated to 45 ℃ by steam, the extractant returns to the extraction unit, and the ammonia distillation effluent subjected to secondary heat exchange is further subjected to biochemical treatment.

Example 4

The oil content of wastewater of a certain coal chemical industry plant is 80 mg/L, the phenol content is 1500 mg/L, and the ammonia nitrogen content is 1000 mg/L, and the method is adopted for treatment as follows:

pretreating coal chemical wastewater and then carrying out oil removal treatment, wherein the oil removal technology comprises gravity oil removal and air flotation oil removal technology, the gravity removal is an oil separation tank, the air flotation oil removal is full-flow pressurized dissolved air flotation, and the oil content of effluent of an oil removal unit is 6 mg/L;

carrying out extraction dephenolization treatment on the coal chemical industry wastewater treated in the step (1), wherein an extraction dephenolization device is a sieve plate extraction tower, an extracting agent is methyl isobutyl ketone, the volume ratio of the extracting agent to water is 1:15, the extraction temperature is 40 ℃, and the phenol content of the extracted effluent is 45 mg/L;

performing ammonia distillation treatment on the wastewater treated in the step (2), wherein the ammonia distillation technology is direct ammonia distillation, the effluent temperature of an ammonia distillation unit is 105 ℃, and the ammonia nitrogen content of the effluent of the ammonia distillation unit is 40 mg/L;

performing heat exchange treatment on the extract liquor in the step (2) and the wastewater treated in the step (3), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extract liquor is 70 ℃, and performing secondary heat exchange treatment on the wastewater after heat exchange;

carrying out pervaporation treatment on the extract liquor heated in the step (4), wherein the pervaporation adopts a vacuum pumping method, the pervaporation membrane is a hydrophilic composite flat membrane, the operating temperature is 70 ℃, the separating factor of the extracting agent is about 18, and the recovery rate is about 98%;

and (3) carrying out secondary heat exchange treatment on the extractant separated in the step (5) and the wastewater subjected to heat exchange in the step (4), wherein the heat exchanger is a plate heat exchanger, the outlet temperature of the extractant is 30 ℃, the extractant is further preheated to 40 ℃ by steam, the extractant returns to the extraction unit, and the ammonia distillation effluent subjected to secondary heat exchange is further subjected to biochemical treatment.

The applicant states that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above detailed process equipment and process flow, i.e. the present invention is not meant to be implemented by relying on the above detailed process equipment and process flow. It should be clear to those skilled in the art that any improvement of the present invention, to the equivalent replacement of each raw material of the present invention, the addition of auxiliary components, the selection of specific modes, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (8)

1. A resource treatment system for coal chemical industry wastewater extraction dephenolization is characterized by comprising an oil removal unit (1), an extraction dephenolization unit (2) and an ammonia distillation unit (3) which are sequentially connected; the extraction dephenolization unit (2) and the ammonia distillation unit (3) are also respectively connected with a primary heat exchange unit (4); the primary heat exchange unit (4) is connected with the pervaporation unit (5), and the pervaporation unit (5) is connected with the secondary heat exchange unit (6); the primary heat exchange unit (4) is also connected with the secondary heat exchange unit (6).

2. The treatment system according to claim 1, wherein the secondary heat exchange unit (6) is further connected to an extractive dephenolation unit (2).

3. The treatment system according to claim 2, wherein the oil removal unit (1) comprises gravity oil removal and air flotation oil removal;

the gravity oil removal is any one of an oil separation tank, an oil separation well, an oil removal tank and coarse graining oil removal;

the air flotation oil removal is any one of full-flow pressurization dissolved air flotation, partial pressurization dissolved air flotation or partial reflux pressurization dissolved air flotation.

4. The treatment system of claim 3, wherein the extraction dephenolation unit (2) adopts any one of a packed extraction tower, a sieve plate extraction tower, a rotary disc extraction tower, a vibrating sieve plate tower or a multi-stage centrifugal extraction tower;

the extractant is at least one of methyl isobutyl ketone, ethyl acetate, benzene or diisopropyl ether.

5. The treatment system according to claim 4, wherein the ammonia distillation unit (3) is any one of direct ammonia distillation or indirect ammonia distillation.

6. The treatment system according to claim 5, wherein the primary heat exchange unit (4) is a heat exchanger;

the heat exchanger is any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger.

7. The treatment system according to claim 6, wherein the pervaporation unit (5) adopts an evacuation method and the pervaporation membrane is a hydrophilic composite flat membrane.

8. The treatment system according to claim 7, wherein the secondary heat exchange unit (6) is a heat exchanger;

the heat exchanger is any one of a floating head type heat exchanger, a fixed tube plate type heat exchanger, a U-shaped tube plate type heat exchanger or a plate type heat exchanger.

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