CN111704305A - Wastewater recycling process and device - Google Patents
Wastewater recycling process and device Download PDFInfo
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- CN111704305A CN111704305A CN202010676061.5A CN202010676061A CN111704305A CN 111704305 A CN111704305 A CN 111704305A CN 202010676061 A CN202010676061 A CN 202010676061A CN 111704305 A CN111704305 A CN 111704305A
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- 239000002351 wastewater Substances 0.000 title claims abstract description 185
- 238000000034 method Methods 0.000 title claims abstract description 64
- 238000004064 recycling Methods 0.000 title claims abstract description 15
- 238000003860 storage Methods 0.000 claims abstract description 64
- 239000003513 alkali Substances 0.000 claims abstract description 62
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 55
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 47
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 46
- 238000004821 distillation Methods 0.000 claims abstract description 40
- OPTASPLRGRRNAP-UHFFFAOYSA-N cytosine Chemical compound NC=1C=CNC(=O)N=1 OPTASPLRGRRNAP-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000008213 purified water Substances 0.000 claims abstract description 32
- 238000011084 recovery Methods 0.000 claims abstract description 28
- 238000002360 preparation method Methods 0.000 claims abstract description 26
- 229940104302 cytosine Drugs 0.000 claims abstract description 16
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 12
- 238000003786 synthesis reaction Methods 0.000 claims abstract description 12
- 229910017053 inorganic salt Inorganic materials 0.000 claims abstract description 9
- 239000007788 liquid Substances 0.000 claims abstract description 9
- 238000009270 solid waste treatment Methods 0.000 claims abstract description 8
- 238000007865 diluting Methods 0.000 claims abstract description 5
- 238000009776 industrial production Methods 0.000 claims abstract description 5
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 72
- 238000000605 extraction Methods 0.000 claims description 17
- 230000020477 pH reduction Effects 0.000 claims description 15
- 238000009833 condensation Methods 0.000 claims description 11
- 230000005494 condensation Effects 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 9
- 239000002910 solid waste Substances 0.000 claims description 6
- 239000010865 sewage Substances 0.000 abstract description 12
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 39
- 230000000694 effects Effects 0.000 description 31
- DHKHKXVYLBGOIT-UHFFFAOYSA-N acetaldehyde Diethyl Acetal Natural products CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 23
- 125000002777 acetyl group Chemical class [H]C([H])([H])C(*)=O 0.000 description 23
- 239000012071 phase Substances 0.000 description 23
- 238000002474 experimental method Methods 0.000 description 14
- 238000007363 ring formation reaction Methods 0.000 description 12
- 239000008346 aqueous phase Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 8
- 239000000126 substance Substances 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 6
- 238000002156 mixing Methods 0.000 description 6
- 238000001704 evaporation Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- WQDUMFSSJAZKTM-UHFFFAOYSA-N Sodium methoxide Chemical compound [Na+].[O-]C WQDUMFSSJAZKTM-UHFFFAOYSA-N 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 3
- 238000011033 desalting Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- WBJINCZRORDGAQ-UHFFFAOYSA-N formic acid ethyl ester Natural products CCOC=O WBJINCZRORDGAQ-UHFFFAOYSA-N 0.000 description 3
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000011021 bench scale process Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 239000004202 carbamide Substances 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000010612 desalination reaction Methods 0.000 description 2
- 239000007792 gaseous phase Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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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
-
- 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
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D239/00—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings
- C07D239/02—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings
- C07D239/24—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members
- C07D239/28—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, directly attached to ring carbon atoms
- C07D239/46—Two or more oxygen, sulphur or nitrogen atoms
- C07D239/47—One nitrogen atom and one oxygen or sulfur atom, e.g. cytosine
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
- C02F2103/36—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
The invention relates to a process and a device for recycling and reusing wastewater, which comprises the following process steps of carrying out single-effect distillation on high-salt, high-COD and deep-color wastewater obtained in the existing cytosine synthesis process to obtain kettle residue and single-effect wastewater without inorganic salt, carrying out solid waste treatment on the kettle residue to obtain residual single-effect wastewater, replacing purified water with the single-effect wastewater, diluting 30% of liquid alkali used in industrial production to obtain 10% of dilute alkali, adding the 10% of dilute alkali into the neutralization process in the cytosine synthesis process to carry out neutralization reaction, and adding a wastewater single-effect distillation kettle and a single-effect wastewater storage tank into the device, wherein the wastewater single-effect distillation kettle is communicated with a mixed alcohol recovery kettle, the wastewater single-effect distillation kettle is communicated with a single-effect wastewater storage tank, and the single-effect wastewater storage tank is communicated with a dilute alkali preparation kettle. The invention can reduce the discharge amount of wastewater and the subsequent sewage treatment cost, and can also reduce the preparation cost of purified water and save resources.
Description
Technical Field
The invention belongs to the technical field of wastewater recovery treatment, and particularly relates to a wastewater recovery and reuse process and a device.
Background
In the existing cytosine synthesis process, acetonitrile, toluene and ethyl formate are generally mixed in a premixing kettle, then corresponding substances are added, and the mixture is respectively subjected to pressure rise, acidification, neutralization and extraction through an autoclave, an acidification kettle, a neutralization kettle and an extraction kettle to obtain a toluene layer and a water layer, the process is shown in figure 1, the toluene layer is subjected to rectification treatment to obtain acetal, the water layer is subjected to recovery through a mixed alcohol recovery kettle to obtain mixed alcohol, then wastewater is discharged, the wastewater is usually high-salt, high-COD and deep-color wastewater, the wastewater can reach the standard after being subjected to triple effect evaporation desalting and complex physicochemical and biochemical wastewater treatment processes, the wastewater is discharged, the wastewater treatment cost is high, water source waste is caused, 10% diluted alkali is required to be added in the neutralization process, the 30% diluted alkali is generally used in the industry, and the 10% diluted alkali obtained after the 30% diluted alkali in the industry and purified water are mixed needs to be added into the neutralization kettle for neutralization reaction, the preparation of the purified water needs four-stage reverse osmosis and other processes to remove inorganic salts, and has high preparation cost and troublesome operation.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a wastewater recycling process and a wastewater recycling device, which can reduce the wastewater discharge amount and the subsequent sewage treatment cost, can also reduce the preparation cost of purified water, and saves resources.
The technical scheme adopted by the invention is as follows: a waste water recycling process comprises the following steps:
A. performing single-effect distillation on high-salt, high-COD and deep-color wastewater obtained in the existing cytosine synthesis process to obtain kettle residue and single-effect wastewater without inorganic salt;
B. carrying out solid waste treatment on the kettle residue to obtain residual single-effect wastewater;
C. replacing purified water with single-effect wastewater, diluting 30% liquid alkali used in industrial production to obtain 10% diluted alkali, and adding the 10% diluted alkali into a neutralization process in a cytosine synthesis process for neutralization reaction.
Specifically, the single-effect distillation of the wastewater in the step A specifically comprises the following steps: and (3) carrying out negative pressure distillation on the wastewater, and carrying out gas phase condensation to obtain the single-effect wastewater without inorganic salts.
Specifically, the still residue includes solid waste salts.
The utility model provides a realize device of waste water recovery reuse technology, prepare cauldron, extraction cauldron, toluene phase storage tank, aqueous phase storage tank, mixed alcohol recovery cauldron and mixed alcohol storage tank including premixing cauldron, autoclave, acidizing cauldron, neutralization cauldron, dilute alkali, premixing cauldron, autoclave, acidizing cauldron, neutralization cauldron and extraction cauldron communicate in proper order, dilute alkali is prepared the cauldron and is linked together with the neutralization cauldron, toluene phase storage tank and aqueous phase storage tank all communicate with the extraction cauldron, the aqueous phase storage tank is linked together with mixed alcohol recovery cauldron, mixed alcohol recovery cauldron is linked together with mixed alcohol storage tank, its characterized in that: the mixed alcohol recovery kettle is also communicated with a wastewater single-effect distillation kettle, the wastewater single-effect distillation kettle is communicated with a single-effect wastewater storage tank, and the single-effect wastewater storage tank is communicated with the dilute alkali preparation kettle.
And a kettle residue outlet is formed in the bottom end of the wastewater single-effect distillation kettle.
The top end of the single-effect waste water storage tank is communicated with the top end of the waste water single-effect distillation kettle, and the single-effect waste water storage tank is communicated with the waste water single-effect distillation kettle through a gas phase condenser.
The invention has the beneficial effects that:
1. the invention adds a wastewater single-effect distillation kettle on the basis of the original process equipment, carries out single-effect distillation treatment on the wastewater discharged from a mixed alcohol recovery kettle to obtain colorless and transparent single-effect wastewater, and recycles the single-effect wastewater to replace purified water to enter a neutralization kettle to prepare 10% diluted alkali.
Drawings
FIG. 1 is a schematic diagram of a conventional cytosine synthesis process;
FIG. 2 is a schematic view of the process of recycling the wastewater according to the present invention.
In the figure: 1. the system comprises a premixing kettle 2, an autoclave 3, an acidification kettle 4, a neutralization kettle 5, a dilute alkali preparation kettle 6, an extraction kettle 7, a toluene phase storage tank 8, a water phase storage tank 9, a mixed alcohol recovery kettle 10, a mixed alcohol storage tank 11, a wastewater single-effect distillation kettle 12, a single-effect wastewater storage tank 13, a kettle residue discharge port 14, a gas phase condenser 15 and a rectifying tower.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort belong to the protection scope of the present invention, and are specifically described below with reference to the embodiments.
Example 1
As shown in fig. 1 and 2, the present invention includes a wastewater recycling process comprising the steps of:
A. performing single-effect distillation on high-salt, high-COD and deep-color wastewater obtained in the existing cytosine synthesis process, namely performing negative pressure distillation on the wastewater, and performing gas-phase condensation treatment to obtain kettle residue and single-effect wastewater without inorganic salt, wherein the main component of the kettle residue is solid waste salt;
B. carrying out solid waste treatment on the kettle residue to obtain residual single-effect wastewater;
C. replacing purified water with single-effect wastewater, diluting 30% liquid alkali used in industrial production to obtain 10% diluted alkali, and adding the 10% diluted alkali into a neutralization process in a cytosine synthesis process for neutralization reaction.
The utility model provides a realize device of waste water recovery reuse technology, including premixing cauldron 1, autoclave 2, acidizing cauldron 3, neutralization kettle 4, dilute alkali preparation cauldron 5, extraction cauldron 6, toluene phase storage tank 7, aqueous phase storage tank 8, mixed alcohol recovery cauldron 9 and mixed alcohol storage tank 10, premixing cauldron 1, autoclave 2, acidizing cauldron 3, neutralization cauldron 4 and extraction cauldron 6 communicate in proper order, dilute alkali preparation cauldron 5 is linked together with neutralization cauldron 4, toluene phase storage tank 7 and aqueous phase storage tank 8 all communicate with extraction cauldron 6, aqueous phase storage tank 8 is linked together with mixed alcohol recovery cauldron 9, mixed alcohol recovery cauldron 9 is linked together with mixed alcohol storage tank 10, mixed alcohol recovery cauldron 9 still communicates has waste water single effect stills 11, waste water single effect stills 11 communicates has single effect waste water storage tank 12, single effect storage tank 12 is linked together with dilute alkali preparation cauldron 5.
During operation, firstly mixing acetonitrile, toluene and ethyl formate in a premixing kettle 1, adding sodium methoxide during mixing, then sequentially entering a high-pressure kettle 2 and an acidification kettle 3, acidifying in the acidification kettle 3, realizing an acidification effect by adding acid ethanol in the acidification kettle 3, then entering a neutralization kettle 4, simultaneously entering 10% diluted alkali prepared in a diluted alkali preparation kettle 5 into the neutralization kettle 4 to perform neutralization reaction with substances in the neutralization kettle 4, then obtaining toluene and water containing methanol and ethanol through extraction, wherein the toluene is on the upper layer, the wastewater is on the lower layer, respectively entering a toluene phase storage tank 7 and a water phase storage tank 8 through separation, the toluene in the toluene phase storage tank 7 enters a rectifying tower 15 to perform subsequent rectification treatment to obtain acetal, the process is industrially referred to as condensation reaction, then performing cyclization reaction, and further synthesizing cytosine by reacting the acetal with urea, the waste water in the water phase storage tank 8 flows into a mixed alcohol recovery kettle 9, the waste water and the mixed alcohol are obtained by separation, the mixed alcohol enters a mixed alcohol storage tank 10, the waste water is high-salt, high-COD and deep-color waste water, the waste water is subjected to triple effect evaporation desalting and then is treated by a complex physicochemical and biochemical sewage treatment process to discharge the waste water reaching the standard, the waste water flows into a waste water single effect distillation kettle 11 to be subjected to single effect distillation treatment, namely, the waste water is subjected to negative pressure distillation to reduce the boiling point of the waste water, the distilled single effect waste water does not contain inorganic salt and flows into a single effect waste water storage tank 12, the residual kettle residue in the waste water single effect distillation kettle 11 mainly contains solid waste salt, the solid waste treatment is carried out after the discharge, the waste water in the single effect waste water storage tank 12 is recycled to replace purified water to flow into a dilute alkali preparation kettle 5, and is mixed and diluted with 30 percent liquid alkali used in industry in proportion to obtain 10 percent dilute alkali, then flows into the neutralization kettle 4 for neutralization reaction, thereby realizing the recycling of the wastewater and reducing the wastewater discharge amount and the subsequent sewage treatment cost.
Specifically, the waste water of the original process is the waste water obtained by mixing CY600 condensation and cyclization waste water of a workshop and waste water at the bottom of an AC3000 dehydration tower, is high-salt, high-COD and deep-color waste water, is subjected to triple effect evaporation and desalination, and is treated by a complex physicochemical and biochemical sewage treatment process to be discharged until reaching the standard, the waste water of the invention is the single-effect waste water obtained by flowing the waste water into a single-effect distillation kettle 11 for negative pressure distillation and gas phase condensation, the single-effect waste water is colorless and transparent, but has the characteristics of high ammonia nitrogen and high COD, if the waste water is directly discharged, the waste water enters a sewage treatment system after being blown off and qualified, can be discharged into a standard waste water working section after physicochemical, biochemical and deep treatment, but in the CY600, alkali used for neutralization in the neutralization process is 10% diluted alkali prepared by 30% liquid alkali and purified water, and water required in the process is diluted alkali for ammonia nitrogen, chemical oxygen and deep treatment, COD has no requirement, but the requirements on inorganic salt ions and colorless transparency in water are higher, and the single-effect wastewater just meets the conditions, so that the single-effect wastewater can be circularly sleeved in the dilute alkali preparation process for acidification and neutralization, the process treatment not only reduces the wastewater discharge and the subsequent sewage treatment cost, but also reduces the preparation cost of purified water, and the process is optimized in multiple items, saves resources, and conforms to the low-cost and green chemical concept.
The invention is used on the basis of the conclusion that the single-effect wastewater does not influence the acetal yield of the whole process, and the conclusion needs to be tested and verified, and the process is as follows:
firstly, when the workshop uses the purified water adopted in the original process without using single effect water, 5 batches/day of data are recorded, and the recorded data are shown in the following table 1:
TABLE 1
| Record batch number | The amount of acetonitrile/kg is added | Purified water/t for preparing 10% diluted alkali | Mass yield of acetal |
| 1 | 190 | 2.01 | 228% |
| 2 | 190 | 2 | 231% |
| 3 | 190 | 2 | 228% |
| 4 | 190 | 2 | 229% |
| 5 | 190 | 2 | 232% |
Then, a bench scale experiment was carried out in the laboratory, 5 condensation experiments were carried out a day, and the experimental data are shown in table 2:
TABLE 2
| Experiment batch number | The amount of acetonitrile/g added | Preparing 10% single-effect waste water/g for dilute alkali reuse | Mass yield of acetal |
| 1 | 19.3 | 200 | 212% |
| 2 | 19.5 | 200 | 233% |
| 3 | 19.8 | 200 | 208% |
| 4 | 19.7 | 200 | 222% |
| 5 | 19.6 | 200 | 215% |
The comparison of the experimental data in table 2 and table 1 shows that in the experiment, the mass yield of the acetal obtained by keeping the ratio of the acetonitrile and the single-effect wastewater equal to the ratio of the acetonitrile and the purified water in the original process is almost the same, so that the acetal obtained by using the single-effect wastewater instead of the purified water has no influence on the mass yield of the acetal, and the method can be used in the actual production. However, the quantity adopted in the experiment is small, so in order to ensure the accuracy of the experimental conclusion, the invention also records data in the actual production so as to be convenient for checking and verifying the experimental result, thereby ensuring the accuracy of the experimental conclusion.
Then, a production experiment was performed in the plant for about one month, and the acetal quality yield in the plant was almost the same according to the experimental data, and 5 batches of the experimental data in one day were selected, as shown in table 3:
TABLE 3
| Experiment batch number | The amount of acetonitrile/kg is added | Preparing 10% diluted alkali single-effect wastewater/t | Mass yield of acetal |
| 1 | 190 | 2 | 231% |
| 2 | 190 | 2 | 230% |
| 3 | 190 | 2 | 229% |
| 4 | 191 | 2 | 228% |
| 5 | 190 | 2 | 230.5% |
According to the table, the single-effect wastewater is used for replacing purified water in actual production, the quality yield of acetal is not influenced, 10t of single-effect water can be mechanically applied to 10% of diluted alkali in one day, more than 3000t of single-effect wastewater can be mechanically applied to one year, namely more than 3000t of purified water is saved, the preparation cost of the purified water is effectively reduced, and a large amount of water resources are saved.
In addition, the wastewater subjected to cyclization treatment in the original process has the characteristics of high salinity and high ammonia nitrogen, the treatment difficulty is high, the treatment is slow, the cyclization cannot be fed once, and the pressure of wastewater discharged by cyclization can be relieved by applying single-effect wastewater, so that the amount of the fed cyclization can be increased by applying the single-effect wastewater instead of purified water, and the yield of cytosine is increased.
Example 2
As shown in fig. 1 and 2, the present invention includes a wastewater recycling process comprising the steps of:
A. performing single-effect distillation on high-salt, high-COD and deep-color wastewater obtained in the existing cytosine synthesis process, namely performing negative pressure distillation on the wastewater, and performing gas-phase condensation treatment to obtain kettle residue and single-effect wastewater without inorganic salt, wherein the main component of the kettle residue is solid waste salt;
B. carrying out solid waste treatment on the kettle residue to obtain residual single-effect wastewater;
C. replacing purified water with single-effect wastewater, diluting 30% liquid alkali used in industrial production to obtain 10% diluted alkali, and adding the 10% diluted alkali into a neutralization process in a cytosine synthesis process for neutralization reaction.
The utility model provides a realize device of waste water recovery reuse technology, including premixing cauldron 1, autoclave 2, acidizing cauldron 3, neutralization kettle 4, dilute alkali preparation cauldron 5, extraction cauldron 6, toluene phase storage tank 7, aqueous phase storage tank 8, mixed alcohol recovery cauldron 9 and mixed alcohol storage tank 10, premixing cauldron 1, autoclave 2, acidizing cauldron 3, neutralization cauldron 4 and extraction cauldron 6 communicate in proper order, dilute alkali preparation cauldron 5 is linked together with neutralization cauldron 4, toluene phase storage tank 7 and aqueous phase storage tank 8 all communicate with extraction cauldron 6, aqueous phase storage tank 8 is linked together with mixed alcohol recovery cauldron 9, mixed alcohol recovery cauldron 9 is linked together with mixed alcohol storage tank 10, mixed alcohol recovery cauldron 9 still communicates has waste water single effect stills 11, waste water single effect stills 11 communicates has single effect waste water storage tank 12, single effect storage tank 12 is linked together with dilute alkali preparation cauldron 5.
For better effect, the bottom end of the wastewater single-effect distillation kettle 11 is provided with a kettle residue discharge port 13, so that the kettle residue is conveniently discharged for solid waste treatment.
For better effect, the top of single-effect waste water storage tank 12 is linked together with the top of waste water single-effect stills 11, through gaseous phase condenser 14 intercommunication between single-effect waste water storage tank 12 and the waste water single-effect stills 11, gaseous phase condenser 14 can accelerate the condensation of single-effect waste water, makes in it gets into single-effect waste water storage tank 12, is favorable to the quick collection of single-effect waste water.
During operation, firstly mixing acetonitrile, toluene and ethyl formate in a premixing kettle 1, adding sodium methoxide during mixing, then sequentially entering a high-pressure kettle 2 and an acidification kettle 3, acidifying in the acidification kettle 3, realizing an acidification effect by adding acid ethanol in the acidification kettle 3, then entering a neutralization kettle 4, simultaneously entering 10% diluted alkali prepared in a diluted alkali preparation kettle 5 into the neutralization kettle 4 to perform neutralization reaction with substances in the neutralization kettle 4, then obtaining toluene and water containing methanol and ethanol through extraction, wherein the toluene is on the upper layer, the wastewater is on the lower layer, respectively entering a toluene phase storage tank 7 and a water phase storage tank 8 through separation, the toluene in the toluene phase storage tank 7 enters a rectifying tower 15 to perform subsequent rectification treatment to obtain acetal, the process is industrially referred to as condensation reaction, then performing cyclization reaction, and further synthesizing cytosine by reacting the acetal with urea, the waste water in the water phase storage tank 8 flows into a mixed alcohol recovery kettle 9, the waste water and the mixed alcohol are obtained by separation, the mixed alcohol enters a mixed alcohol storage tank 10, the waste water is high-salt, high-COD and deep-color waste water, the waste water is subjected to triple effect evaporation desalting and then is treated by a complex physicochemical and biochemical sewage treatment process to discharge the waste water reaching the standard, the waste water flows into a waste water single effect distillation kettle 11 to be subjected to single effect distillation treatment, namely, the waste water is subjected to negative pressure distillation to reduce the boiling point of the waste water, the distilled single effect waste water does not contain inorganic salt and flows into a single effect waste water storage tank 12, the residual kettle residue in the waste water single effect distillation kettle 11 mainly contains solid waste salt, the solid waste treatment is carried out after the discharge, the waste water in the single effect waste water storage tank 12 is recycled to replace purified water to flow into a dilute alkali preparation kettle 5, and is mixed and diluted with 30 percent liquid alkali used in industry in proportion to obtain 10 percent dilute alkali, then flows into the neutralization kettle 4 for neutralization reaction, thereby realizing the recycling of the wastewater and reducing the wastewater discharge amount and the subsequent sewage treatment cost.
Specifically, the waste water of the original process is the waste water obtained by mixing CY600 condensation and cyclization waste water of a workshop and waste water at the bottom of an AC3000 dehydration tower, is high-salt, high-COD and deep-color waste water, is subjected to triple effect evaporation and desalination, and is treated by a complex physicochemical and biochemical sewage treatment process to be discharged until reaching the standard, the waste water of the invention is the single-effect waste water obtained by flowing the waste water into a single-effect distillation kettle 11 for negative pressure distillation and gas phase condensation, the single-effect waste water is colorless and transparent, but has the characteristics of high ammonia nitrogen and high COD, if the waste water is directly discharged, the waste water enters a sewage treatment system after being blown off and qualified, can be discharged into a standard waste water working section after physicochemical, biochemical and deep treatment, but in the CY600, alkali used for neutralization in the neutralization process is 10% diluted alkali prepared by 30% liquid alkali and purified water, and water required in the process is diluted alkali for ammonia nitrogen, chemical oxygen and deep treatment, COD has no requirement, but the requirements on inorganic salt ions and colorless transparency in water are higher, and the single-effect wastewater just meets the conditions, so that the single-effect wastewater can be circularly sleeved in the dilute alkali preparation process for acidification and neutralization, the process treatment not only reduces the wastewater discharge and the subsequent sewage treatment cost, but also reduces the preparation cost of purified water, and the process is optimized in multiple items, saves resources, and conforms to the low-cost and green chemical concept.
The invention is used on the basis of the conclusion that the single-effect wastewater does not influence the acetal yield of the whole process, and the conclusion needs to be tested and verified, and the process is as follows:
firstly, when the workshop uses the purified water adopted in the original process without using single effect water, 5 batches/day of data are recorded, and the recorded data are shown in the following table 1:
TABLE 1
| Record batch number | The amount of acetonitrile/kg is added | Purified water/t for preparing 10% diluted alkali | Mass yield of acetal |
| 1 | 190 | 2.01 | 228% |
| 2 | 190 | 2 | 231% |
| 3 | 190 | 2 | 228% |
| 4 | 190 | 2 | 229% |
| 5 | 190 | 2 | 232% |
Then, a bench scale experiment was carried out in the laboratory, 5 condensation experiments were carried out a day, and the experimental data are shown in table 2:
TABLE 2
| Experiment batch number | The amount of acetonitrile/g added | Preparing 10% single-effect waste water/g for dilute alkali reuse | Mass yield of acetal |
| 1 | 19.3 | 200 | 212% |
| 2 | 19.5 | 200 | 233% |
| 3 | 19.8 | 200 | 208% |
| 4 | 19.7 | 200 | 222% |
| 5 | 19.6 | 200 | 215% |
The comparison of the experimental data in table 2 and table 1 shows that in the experiment, the mass yield of the acetal obtained by keeping the ratio of the acetonitrile and the single-effect wastewater equal to the ratio of the acetonitrile and the purified water in the original process is almost the same, so that the acetal obtained by using the single-effect wastewater instead of the purified water has no influence on the mass yield of the acetal, and the method can be used in the actual production. However, the quantity adopted in the experiment is small, so in order to ensure the accuracy of the experimental conclusion, the invention also records data in the actual production so as to be convenient for checking and verifying the experimental result, thereby ensuring the accuracy of the experimental conclusion.
Then, a production experiment was performed in the plant for about one month, and the acetal quality yield in the plant was almost the same according to the experimental data, and 5 batches of the experimental data in one day were selected, as shown in table 3:
TABLE 3
| Experiment batch number | The amount of acetonitrile/kg is added | Preparing 10% diluted alkali single-effect wastewater/t | Mass yield of acetal |
| 1 | 190 | 2 | 231% |
| 2 | 190 | 2 | 230% |
| 3 | 190 | 2 | 229% |
| 4 | 191 | 2 | 228% |
| 5 | 190 | 2 | 230.5% |
According to the table, the single-effect wastewater is used for replacing purified water in actual production, the quality yield of acetal is not influenced, 10t of single-effect water can be mechanically applied to 10% of diluted alkali in one day, more than 3000t of single-effect wastewater can be mechanically applied to one year, namely more than 3000t of purified water is saved, the preparation cost of the purified water is effectively reduced, and a large amount of water resources are saved.
In addition, the wastewater subjected to cyclization treatment in the original process has the characteristics of high salinity and high ammonia nitrogen, the treatment difficulty is high, the treatment is slow, the cyclization cannot be fed once, and the pressure of wastewater discharged by cyclization can be relieved by applying single-effect wastewater, so that the amount of the fed cyclization can be increased by applying the single-effect wastewater instead of purified water, and the yield of cytosine is increased.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (6)
1. A waste water recycling process is characterized by comprising the following steps:
A. performing single-effect distillation on high-salt, high-COD and deep-color wastewater obtained in the existing cytosine synthesis process to obtain kettle residue and single-effect wastewater without inorganic salt;
B. carrying out solid waste treatment on the kettle residue to obtain residual single-effect wastewater;
C. replacing purified water with single-effect wastewater, diluting 30% liquid alkali used in industrial production to obtain 10% diluted alkali, and adding the 10% diluted alkali into a neutralization process in a cytosine synthesis process for neutralization reaction.
2. The wastewater recycling process according to claim 1, wherein the step A of subjecting the wastewater to single-effect distillation specifically comprises: and (3) carrying out negative pressure distillation on the wastewater, and carrying out gas phase condensation to obtain the single-effect wastewater without inorganic salts.
3. The wastewater recycling process according to claim 1, characterized in that: the still residue includes solid waste salt.
4. The device for realizing the wastewater recycling process of claim 1 comprises a premixing kettle, an autoclave, an acidification kettle, a neutralization kettle, a diluted alkali preparation kettle, an extraction kettle, a toluene phase storage tank, a water phase storage tank, a mixed alcohol recovery kettle and a mixed alcohol storage tank, wherein the premixing kettle, the autoclave, the acidification kettle, the neutralization kettle and the extraction kettle are sequentially communicated, the diluted alkali preparation kettle is communicated with the neutralization kettle, the toluene phase storage tank and the water phase storage tank are both communicated with the extraction kettle, the water phase storage tank is communicated with the mixed alcohol recovery kettle, and the mixed alcohol recovery kettle is communicated with the mixed alcohol storage tank, and is characterized in that: the mixed alcohol recovery kettle is also communicated with a wastewater single-effect distillation kettle, the wastewater single-effect distillation kettle is communicated with a single-effect wastewater storage tank, and the single-effect wastewater storage tank is communicated with the dilute alkali preparation kettle.
5. The apparatus of claim 4, wherein: and a kettle residue outlet is formed in the bottom end of the wastewater single-effect distillation kettle.
6. The apparatus of claim 4, wherein: the top end of the single-effect waste water storage tank is communicated with the top end of the waste water single-effect distillation kettle, and the single-effect waste water storage tank is communicated with the waste water single-effect distillation kettle through a gas phase condenser.
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| FR1454462A (en) * | 1965-08-12 | 1966-02-11 | Raffinage Cie Francaise | Process for recovering alkylamides |
| CN102558077A (en) * | 2012-03-02 | 2012-07-11 | 甘肃聚隆精细化工有限公司 | Process system capable of continuously producing methylbenzotriazole (TTA) and production method |
| CN103570176A (en) * | 2013-11-01 | 2014-02-12 | 安徽金禾实业股份有限公司 | Method and device for processing waste water of chlorination workshop section in production of pyridinium |
| CN204079685U (en) * | 2014-07-25 | 2015-01-07 | 太仓塑料助剂厂有限公司 | A kind for the treatment of unit of high salinity high-COD waste water |
| CN108586268A (en) * | 2018-01-22 | 2018-09-28 | 精华制药集团南通有限公司 | N, the method for accelerine recycling are recycled in a kind of Flucytosine chlorinated effluent |
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2020
- 2020-07-14 CN CN202010676061.5A patent/CN111704305A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1454462A (en) * | 1965-08-12 | 1966-02-11 | Raffinage Cie Francaise | Process for recovering alkylamides |
| CN102558077A (en) * | 2012-03-02 | 2012-07-11 | 甘肃聚隆精细化工有限公司 | Process system capable of continuously producing methylbenzotriazole (TTA) and production method |
| CN103570176A (en) * | 2013-11-01 | 2014-02-12 | 安徽金禾实业股份有限公司 | Method and device for processing waste water of chlorination workshop section in production of pyridinium |
| CN204079685U (en) * | 2014-07-25 | 2015-01-07 | 太仓塑料助剂厂有限公司 | A kind for the treatment of unit of high salinity high-COD waste water |
| CN108586268A (en) * | 2018-01-22 | 2018-09-28 | 精华制药集团南通有限公司 | N, the method for accelerine recycling are recycled in a kind of Flucytosine chlorinated effluent |
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