CN116082137A - Method for recycling 1,3-cyclohexanedione in wastewater - Google Patents
Method for recycling 1,3-cyclohexanedione in wastewater Download PDFInfo
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- CN116082137A CN116082137A CN202211703836.9A CN202211703836A CN116082137A CN 116082137 A CN116082137 A CN 116082137A CN 202211703836 A CN202211703836 A CN 202211703836A CN 116082137 A CN116082137 A CN 116082137A
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- cyclohexanedione
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- HJSLFCCWAKVHIW-UHFFFAOYSA-N cyclohexane-1,3-dione Chemical compound O=C1CCCC(=O)C1 HJSLFCCWAKVHIW-UHFFFAOYSA-N 0.000 title claims abstract description 121
- 239000002351 wastewater Substances 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 72
- 238000004064 recycling Methods 0.000 title abstract description 16
- 239000012528 membrane Substances 0.000 claims abstract description 93
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 88
- 238000001728 nano-filtration Methods 0.000 claims abstract description 64
- 239000011780 sodium chloride Substances 0.000 claims abstract description 44
- 239000012141 concentrate Substances 0.000 claims abstract description 34
- 239000007788 liquid Substances 0.000 claims abstract description 27
- 238000001471 micro-filtration Methods 0.000 claims abstract description 25
- 239000012267 brine Substances 0.000 claims abstract description 16
- 238000001914 filtration Methods 0.000 claims abstract description 16
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims abstract description 16
- 238000001816 cooling Methods 0.000 claims abstract description 15
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 239000000243 solution Substances 0.000 claims description 42
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 41
- 238000002425 crystallisation Methods 0.000 claims description 16
- 230000008025 crystallization Effects 0.000 claims description 16
- GHMLBKRAJCXXBS-UHFFFAOYSA-N resorcinol Chemical compound OC1=CC=CC(O)=C1 GHMLBKRAJCXXBS-UHFFFAOYSA-N 0.000 claims description 8
- 239000012510 hollow fiber Substances 0.000 claims description 6
- 229920002678 cellulose Polymers 0.000 claims description 2
- 239000001913 cellulose Substances 0.000 claims description 2
- 239000002131 composite material Substances 0.000 claims description 2
- 239000002120 nanofilm Substances 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims description 2
- 239000000047 product Substances 0.000 abstract description 45
- 239000006227 byproduct Substances 0.000 abstract description 17
- 150000003839 salts Chemical class 0.000 abstract description 13
- 239000005416 organic matter Substances 0.000 abstract description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 30
- 230000000052 comparative effect Effects 0.000 description 20
- 238000003756 stirring Methods 0.000 description 20
- 238000004140 cleaning Methods 0.000 description 19
- 238000011084 recovery Methods 0.000 description 15
- 238000004519 manufacturing process Methods 0.000 description 13
- 238000001704 evaporation Methods 0.000 description 11
- 230000008020 evaporation Effects 0.000 description 11
- 239000012452 mother liquor Substances 0.000 description 10
- 238000001556 precipitation Methods 0.000 description 10
- 239000010865 sewage Substances 0.000 description 10
- 239000011347 resin Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 238000004821 distillation Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 2
- 230000020477 pH reduction Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- 239000005578 Mesotrione Substances 0.000 description 1
- 239000005618 Sulcotrione Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- -1 anthradansienone Chemical compound 0.000 description 1
- 239000002111 antiemetic agent Substances 0.000 description 1
- 239000002220 antihypertensive agent Substances 0.000 description 1
- 229940127088 antihypertensive drug Drugs 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- NPAKNKYSJIDKMW-UHFFFAOYSA-N carvedilol Chemical compound COC1=CC=CC=C1OCCNCC(O)COC1=CC=CC2=NC3=CC=C[CH]C3=C12 NPAKNKYSJIDKMW-UHFFFAOYSA-N 0.000 description 1
- 229960004195 carvedilol Drugs 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002363 herbicidal effect Effects 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- KPUREKXXPHOJQT-UHFFFAOYSA-N mesotrione Chemical compound [O-][N+](=O)C1=CC(S(=O)(=O)C)=CC=C1C(=O)C1C(=O)CCCC1=O KPUREKXXPHOJQT-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- PQTBTIFWAXVEPB-UHFFFAOYSA-N sulcotrione Chemical compound ClC1=CC(S(=O)(=O)C)=CC=C1C(=O)C1C(=O)CCCC1=O PQTBTIFWAXVEPB-UHFFFAOYSA-N 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/04—Chlorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/14—Purification
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/786—Separation; Purification; Stabilisation; Use of additives by membrane separation process, e.g. pervaporation, perstraction, reverse osmosis
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/048—Purification of waste water by evaporation
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/38—Treatment of water, waste water, or sewage by centrifugal separation
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F2001/5218—Crystallization
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- C02F2101/30—Organic compounds
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- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
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- C07C2601/14—The ring being saturated
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Abstract
The invention provides a method for recycling 1,3-cyclohexanedione in wastewater, which comprises the steps of filtering wastewater produced by 1,3-cyclohexanedione through a microfiltration membrane to remove insoluble impurities in the wastewater and obtain enrichment liquid; filtering the enriched liquid by a nanofiltration membrane, and separating to obtain brine and 1,3-cyclohexanedione concentrated liquid; cooling, crystallizing and centrifuging the 1,3-cyclohexanedione concentrate to obtain 1, 3-cyclohexanedione; concentrating the brine to obtain a byproduct sodium chloride. According to the invention, the nanofiltration membrane is adopted to recover the 1,3-cyclohexanedione in the process wastewater, so that the 1,3-cyclohexanedione in the wastewater is enriched and purified, part of process products are recovered, and the product yield is improved; and the organic matter content in the wastewater is reduced, the treatment difficulty of the wastewater is reduced, and the byproduct salt content after the wastewater is concentrated is improved.
Description
Technical Field
The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for recycling 1,3-cyclohexanedione in wastewater.
Background
1,3-cyclohexanedione (English name: 1, 3-cyclohexanedione) is an important organic synthesis intermediate, and can be used for preparing specific antihypertensive drugs such as carvedilol, antiemetic drugs such as anthradansienone, herbicide sulcotrione, mesotrione and the like. The existing preparation method of the 1,3-cyclohexanedione comprises the following steps: the catalyst is hydrogenated under the alkaline condition of resorcinol, and then the 1,3-cyclohexanedione product is obtained through acidification and crystallization, a large amount of high-concentration sodium chloride wastewater is generated in the production process, and part of the product is dissolved in the wastewater. In the prior art, the wastewater of 1,3-cyclohexanedione is usually subjected to evaporation concentration to separate sodium chloride from the wastewater; however, 1,3-cyclohexanedione in the wastewater is unstable in structure due to high boiling point, and is concentrated and converged into macromolecular organic matters through distillation to deteriorate, so that the macromolecular organic matters are entrained in sodium chloride to be separated out together; therefore, the content of sodium chloride which is a byproduct of distillation concentration is also low, and the appearance quality is poor, so that the subsequent treatment and use are affected.
Patent CN20211039681. X discloses a recycling treatment process for 1,3-cyclohexanedione wastewater, and a method for treating 1,3-cyclohexanedione production wastewater by using adsorption resin in patent CN202110156373.8, wherein macroporous resin is adopted to selectively adsorb 1,3-cyclohexanedione in the wastewater, resin after saturation is adsorbed is resolved by alkali liquor, high-concentration 1,3-cyclohexanedione alkaline concentrate is obtained after resolution, and then an acidification crystallization is carried out to obtain a 1,3-cyclohexanedione product. Although the method can utilize macroporous resin to selectively adsorb and separate to obtain a 1,3-cyclohexanedione product, a large amount of high-salt wastewater is generated in the resolving-acidifying process, the total amount of macroporous resin adsorption is limited, the resin consumption in the wastewater treatment process is large, the treatment efficiency is low, and the economical efficiency is poor; the product performance is unstable, and the treatment process is easy to deteriorate.
Because of the problems, a treatment method for 1,3-cyclohexanedione wastewater is highly demanded, which has high treatment efficiency, high recovery rate, good selectivity and environmental protection.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a method for recycling 1,3-cyclohexanedione in wastewater.
The invention provides a method for recycling 1,3-cyclohexanedione in wastewater, which comprises the following steps:
s1: filtering the wastewater by a microfiltration membrane to remove insoluble impurities in the wastewater, thereby obtaining an enrichment solution;
s2: filtering the enriched liquid obtained in the step S1 by a nanofiltration membrane, and separating to obtain brine and 1,3-cyclohexanedione concentrated liquid;
s3: and (3) cooling, crystallizing and centrifuging the 1,3-cyclohexanedione concentrate obtained in the step (S2) to obtain the 1, 3-cyclohexanedione.
In the step S1, the sodium chloride content in the wastewater is 0 to 25wt% and the 1,3-cyclohexanedione content is 0 to 10wt%.
As a specific embodiment of the invention, in the step S1, the water content in the wastewater is 73.2-77.3 wt%, the sodium chloride content is 18-22 wt%, the 1,3-cyclohexanedione content is 4.0-4.5 wt%, the resorcinol content is less than or equal to 0.2wt%, and the other organic impurities are less than or equal to 0.1wt%.
In the step S1, the microfiltration membrane is an aqueous microfiltration membrane, preferably a mixed cellulose membrane; the aperture of the microfiltration membrane is 0.1-5.0 um, preferably 0.1-1.0 um; the microfiltration membrane component is tubular, hollow fiber type, flat plate type, preferably tubular; the interception rate is more than or equal to 95 percent.
In the step S1, the operation pressure of the wastewater is 0.05 to 0.4Mpa, preferably 0.05 to 0.2Mpa; the pH value of the wastewater is 2.0-4.0.
In the step S2, the nanofiltration separation temperature is 15 to 35 ℃, preferably 25 to 35 ℃.
In the step S2, the nanofiltration membrane is a polymer nanofiltration membrane, preferably a polypiperazine composite membrane; the aperture of the nano film is 0.5-5.0 nm, preferably 0.5-3.0 um; the microfiltration membrane component is tubular, hollow fiber type, plate type and roll type, preferably hollow fiber type; the interception rate is more than 98%.
In the step S2, the operating pressure of the wastewater is 0.2 to 1.0Mpa, preferably 0.3 to 0.7Mpa, and the pH of the wastewater is 2.0 to 4.0.
In the step S2, the brine is concentrated to recover sodium chloride.
In a specific embodiment of the present invention, in the step S3, the crystallization temperature is 0 to 5 ℃.
The above-mentioned raw materials in the present invention are all self-made or commercially available, and the present invention is not particularly limited thereto.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention utilizes the selective permeability of the nanofiltration membrane, the retention rate of 1,3-cyclohexanedione in the wastewater reaches more than 99 percent, the products dissolved in the wastewater in the production process can be completely recovered, the product yield is obviously improved, and the economic benefit is created.
2. The COD (chemical oxygen demand) of the wastewater treated by the method is removed to 100mg/L, the COD removal rate is over 99.5 percent, the content of byproducts after distillation and concentration is more than or equal to 99 percent, the appearance is white crystals, and the industrial salt quality index is achieved.
3. The method of the invention does not produce secondary pollution and is environment-friendly.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
The invention is further illustrated below in connection with specific examples, which are not to be construed as limiting the invention in any way.
The microfiltration membrane used in each example is CN-CA microfiltration membrane of blue star membrane industry Co., ltd, and the membrane aperture is 0.1-1.0 um;
the nanofiltration membrane used in each example is a blue star membrane industry Co., ltd. B-N70-8040-3 nanofiltration membrane, and the pore diameter of the membrane is 0.5-3.0 um;
the 1,3-cyclohexanedione process wastewater used in the examples had a water content of 75% by weight, a sodium chloride content of 20.62% by weight, a 1,3-cyclohexanedione content of 4.2% by weight, a resorcinol content of 0.1% by weight and other organic impurities content of 0.08% by weight.
Example 1
The embodiment provides a method for recycling 1,3-cyclohexanedione in 1,3-cyclohexanedione process wastewater, which comprises the following specific details:
s1: the production of 1,3-cyclohexanedione produced 125m 3 Directly cooling the process wastewater (pH=2.5, COD=45123 mg/L) to 25 ℃ through a heat exchanger, and transferring to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.05Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.3MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentration procedure for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, stirring, cooling to 5 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; nanofiltration membrane10000m per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Example 1 recovered 5.26t of 1,3-cyclohexanedione, product content 99.2%, recovery of 1,3-cyclohexanedione 93.9%; the brine is concentrated and recycled to obtain 24.6t of byproduct sodium chloride with the content of 99.2 percent.
Example 2
The embodiment provides a method for recycling 1,3-cyclohexanedione in 1,3-cyclohexanedione process wastewater, which comprises the following specific details:
s1: 105m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=3.5, COD=51315 mg/L) is directly cooled to 30 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.1Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.4MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 3 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Example 2 recovered 5.23t of 1,3-cyclohexanedione product with a product content of 99.5% and a recovery of 1,3-cyclohexanedione of 95.6%; and concentrating and recycling the brine to obtain 20.9t of byproduct sodium chloride with the content of 99.7 percent.
Example 3
The embodiment provides a method for recycling 1,3-cyclohexanedione in 1,3-cyclohexanedione process wastewater, which comprises the following specific details:
s1: 150m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=2.0, COD= 52341 mg/L) is directly cooled to 35 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.15Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.6MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 2 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Example 3 recovery yields 7.45t of 1,3-cyclohexanedione product with a product content of 99.1% and a 1,3-cyclohexanedione recovery of 94.9%; the brine is concentrated and recycled to obtain 29.3t of byproduct sodium chloride with the content of 99.4 percent.
Example 4
The embodiment provides a method for recycling 1,3-cyclohexanedione in 1,3-cyclohexanedione process wastewater, which comprises the following specific details:
s1: 138m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=4.0, COD=48233 mg/L) is directly cooled to 33 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.2Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.7MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, stirring, cooling to 0 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Example 4 recovery yields 6.30t of 1,3-cyclohexanedione product with a product content of 99.3% and a recovery of 1,3-cyclohexanedione of 95.4%; and concentrating and recycling the brine to obtain 25.6t of byproduct sodium chloride with the content of 99.5%.
Comparative example 1
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: the production of 1,3-cyclohexanedione produced 125m 3 Directly cooling the process wastewater (pH=2.5, COD=45123 mg/L) to 38 ℃ through a heat exchanger, and transferring to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.05Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.3MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentration procedure for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, stirring, cooling to 5 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; nanofiltration membraneTreatment of 10000m 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Comparative example 1 recovered 5.22t of 1,3-cyclohexanedione reject, product content 77.2%, recovery of 1,3-cyclohexanedione 70.3%; the brine is concentrated and recycled to obtain 24.7t of byproduct sodium chloride with the content of 95.1 percent. The heat exchanger has over high temperature, the product is easy to deteriorate, and the product content is reduced.
Comparative example 2
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: 105m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=3.5, COD=51315 mg/L) is directly cooled to 13 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.1Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.4MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 3 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Comparative example 2 recovered 5.22t of 1,3-cyclohexanedione product with a product content of 99.7% and a recovery of 1,3-cyclohexanedione of 95.6%; and concentrating and recycling the brine to obtain a byproduct sodium chloride with the content of 20.6t and 99.3 percent. The treatment effect is consistent with that of the embodiment, but the temperature of the heat exchanger is too low, so that the energy consumption is increased, and the economical efficiency is poor.
Comparative example 3
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: 150m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=5.0, COD= 52341 mg/L) is directly cooled to 35 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.15Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.6MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 2 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Comparative example 3 recovered 1.45t of 1,3-cyclohexanedione product with a product content of 99.0% and a recovery of 1,3-cyclohexanedione of 18.9%; the brine is concentrated and recycled to obtain 32.8t of byproduct sodium chloride with the content of 90.8 percent. The pH of the wastewater exceeds 4.0, the recovery rate of the product is reduced, and the content of byproduct sodium chloride is reduced.
Comparative example 4
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: 150m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=1.0, COD= 52341 mg/L) is directly cooled to 35 ℃ by a heat exchanger and then transferredTo a wastewater transfer tank at a speed of 2m 3 The flow rate/h and the running pressure of 0.15Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.6MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 2 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Comparative example 4 recovered 3.45t of 1,3-cyclohexanedione product with a product content of 99.3% and a recovery of 1,3-cyclohexanedione of 44.2%; the brine is concentrated and recycled to obtain 31.8t of byproduct sodium chloride with the content of 93.5 percent. The pH of the wastewater is lower than 2.0, the recovery rate of the product is reduced, and the content of byproduct sodium chloride is reduced.
Comparative example 5
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: 138m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=4.0, COD=48233 mg/L) is directly cooled to 33 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.2Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.7MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, starting stirring, cooling to 8 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 And (3) carrying out backflushing cleaning from the nanofiltration membrane water outlet at the flow rate of/h, and enabling backflushing cleaning liquid to enter a sewage station for treatment.
Comparative example 5 recovered 5.70t of 1,3-cyclohexanedione product, 98.6% product content, 85.8% recovery of 1, 3-cyclohexanedione; and concentrating and recycling the brine to obtain 25.5t of byproduct sodium chloride with the content of 99.3 percent. The crystallization temperature exceeds 5 ℃, and the product content is reduced.
Comparative example 6
This comparative example provides a method for recovering 1,3-cyclohexanedione from 1,3-cyclohexanedione process wastewater, the specific details of which are as follows:
s1: 138m to be produced in the production of 1,3-cyclohexanedione 3 The process wastewater (pH=4.0, COD=48233 mg/L) is directly cooled to 33 ℃ by a heat exchanger and then is transferred to a wastewater transfer tank for 2m 3 The flow rate/h and the running pressure of 0.2Mpa are subjected to preliminary filtration by a microfiltration membrane to obtain an enrichment solution;
s2: the enriched liquid obtained in the step S1 enters through a nanofiltration membrane water inlet, and the operation pressure is 0.7MPa; the outlet of the nanofiltration membrane is used for obtaining purified sodium chloride solution, and the sodium chloride solution can enter a wastewater concentrated water process for evaporation and salt precipitation; and (3) transferring the 1,3-cyclohexanedione concentrate obtained from the concentrated water outlet of the nanofiltration membrane into a concentrate temporary tank for standby.
S3: 3.5m of the 1,3-cyclohexanedione concentrate obtained in the step S2 is added into each kettle 3 Transferring into a crystallization kettle, stirring, cooling to-5 ℃, stirring for 30min, centrifuging to obtain a 1,3-cyclohexanedione product;
s4: the centrifugate enters the step S2 again for continuous treatment; 10000m of nanofiltration membrane per treatment 3 After the mother liquor waste water is washed, 0.5m of sodium hydroxide solution with the concentration of 0.5 percent is used 3 The flow rate/h is backflushed from the nanofiltration membrane water outletCleaning, and introducing the backflushing cleaning liquid into a sewage station for treatment.
Comparative example 6 recovered 6.32t of 1,3-cyclohexanedione product, 98.6% product content, 95.4% recovery of 1, 3-cyclohexanedione; and concentrating and recycling the brine to obtain 25.6t of byproduct sodium chloride with the content of 99.4 percent. The crystallization temperature is lower than 0 ℃, other impurities are separated out, the product content is reduced, the energy consumption is increased, and the economical efficiency is poor.
The technical effects of examples 1-4 and comparative examples 1-6 are tabulated against one another as shown in Table 1:
TABLE 1 technical effects of examples 1-4 and comparative examples 1-6
In conclusion, the nanofiltration membrane is adopted to recycle the 1,3-cyclohexanedione in the process wastewater, so that the 1,3-cyclohexanedione in the wastewater is enriched and purified, part of process products are recycled, and the product yield is improved; and the organic matter content in the wastewater is reduced, the treatment difficulty of the wastewater is reduced, and the byproduct salt content after the wastewater is concentrated is improved.
Any numerical value recited in this disclosure includes all values incremented by one unit from the lowest value to the highest value if there is only a two unit interval between any lowest value and any highest value. For example, if the amount of one component, or the value of a process variable such as temperature, pressure, time, etc., is stated to be 50-90, it is meant in this specification that values such as 51-89, 52-88 … …, and 69-71, and 70-71 are specifically recited. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 units may be considered as appropriate. This is only a few examples of the specific designations. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.
It should be noted that the above-described embodiments are only for explaining the present invention and do not constitute any limitation of the present invention. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.
Claims (10)
1. A method for recovering 1,3-cyclohexanedione from wastewater, comprising the steps of:
s1: filtering the wastewater by a microfiltration membrane to remove insoluble impurities in the wastewater, thereby obtaining an enrichment solution;
s2: filtering the enriched liquid obtained in the step S1 by a nanofiltration membrane, and separating to obtain brine and 1,3-cyclohexanedione concentrated liquid;
s3: and (3) cooling, crystallizing and centrifuging the 1,3-cyclohexanedione concentrate obtained in the step (S2) to obtain the 1, 3-cyclohexanedione.
2. The method according to claim 1, wherein in the step S1, the sodium chloride content in the wastewater is 0 to 25wt% and the 1,3-cyclohexanedione content is 0 to 10wt%.
3. The method according to claim 2, wherein in the step S1, the water content in the wastewater is 73.2-77.3 wt%, the sodium chloride content is 18-22 wt%, the 1,3-cyclohexanedione content is 4.0-4.5 wt%, the resorcinol content is less than or equal to 0.2wt%, and the other organic impurities are less than or equal to 0.1wt%.
4. A method according to any one of claims 1-3, wherein in step S1 the microfiltration membrane is an aqueous microfiltration membrane, preferably a mixed cellulose membrane; the aperture of the microfiltration membrane is 0.1-5.0 um, preferably 0.1-1.0 um; the microfiltration membrane component is tubular, hollow fiber type, flat plate type, preferably tubular; the interception rate is more than or equal to 95 percent.
5. The method according to any one of claims 1 to 4, wherein in step S1, the operating pressure of the wastewater is 0.05 to 0.4Mpa, preferably 0.05 to 0.2Mpa; the pH value of the wastewater is 2.0-4.0.
6. The method according to any one of claims 1-5, wherein in step S2 the nanofiltration separation temperature is 15-35 ℃, preferably 25-35 ℃.
7. The method according to any one of claims 1 to 6, wherein in step S2, the nanofiltration membrane is a polymeric nanofiltration membrane, preferably a polypiperazine-based composite membrane; the aperture of the nano film is 0.5-5.0 nm, preferably 0.5-3.0 um; the microfiltration membrane component is tubular, hollow fiber type, plate type and roll type, preferably hollow fiber type; the interception rate is more than 98%.
8. The method according to any one of claims 1 to 7, wherein in step S2, the wastewater is operated at a pressure of 0.2 to 1.0Mpa, preferably 0.3 to 0.7Mpa, and a pH of 2.0 to 4.0.
9. The method according to any one of claims 1 to 8, wherein in step S2, the brine is concentrated to recover sodium chloride.
10. The process according to any one of claims 1 to 9, wherein in step S3, the crystallization temperature is 0 to 5 ℃.
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| CN111392946A (en) * | 2020-04-01 | 2020-07-10 | 陕西蓝深特种树脂有限公司 | Method for recovering 1,3 cyclohexanedione from wastewater containing 1,3 cyclohexanedione |
| CN111573950A (en) * | 2020-05-29 | 2020-08-25 | 盛隆资源再生（无锡）有限公司 | Method for recycling and treating wastewater containing organic solvent |
| CN112978845A (en) * | 2021-04-14 | 2021-06-18 | 南京简迪环境工程有限公司 | Recycling treatment process for 1, 3-cyclohexanedione wastewater |
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| CN111392946A (en) * | 2020-04-01 | 2020-07-10 | 陕西蓝深特种树脂有限公司 | Method for recovering 1,3 cyclohexanedione from wastewater containing 1,3 cyclohexanedione |
| CN111573950A (en) * | 2020-05-29 | 2020-08-25 | 盛隆资源再生（无锡）有限公司 | Method for recycling and treating wastewater containing organic solvent |
| CN112978845A (en) * | 2021-04-14 | 2021-06-18 | 南京简迪环境工程有限公司 | Recycling treatment process for 1, 3-cyclohexanedione wastewater |
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