Method and device for comprehensive utilization of treatment resources of cyclopentadecanolide perfume production wastewater

Abstract

The invention discloses a method and a device for comprehensive utilization of treatment resources of cyclopentadecanolide perfume production wastewater, and relates to the technical field of cyclopentadecanolide perfume production. Comprising the steps of neutralizing acetic acid wastewater, performing low-temperature vacuum evaporation on the wastewater, applying evaporation condensate water, performing solid-liquid separation on an evaporation concentrated solution, distilling the concentrated solution to recycle toluene, and reusing solid crystallization recrystallized sodium acetate, so that wastewater up-to-standard discharge is realized, resources are recycled, the energy consumption of wastewater treatment is reduced, and the production cost is reduced. And the method is not limited by brine concentration.

Description

Technical Field

[0001] The invention belongs to the technical field of cyclopentadecalactone fragrance production, and specifically relates to a method and a device for comprehensive utilization of wastewater treatment resources in the production of cyclopentadecalactone fragrance. Background Art

[0002] Macrolide compounds mainly refer to molecules with more than twelve carbon atoms and at least one ester bond in the macrocyclic skeleton. Cyclopentadecalactone, also known as hibiscus, is a very important macrocyclic musk. It not only has the scent of musk, but also has the aroma of ambergris. The fragrance is rich, lasting, delicate, and has strong penetration. It is widely used in the preparation of perfumes, cosmetics, and food flavors. At the same time, it has a good fixative effect, so it is widely used in daily fragrances such as woody, oriental, fantasy, amber, and floral. It is also an important pharmaceutical synthesis intermediate, used in daily chemical, pharmaceutical and other industries. Cyclopentadecalactone is an indispensable raw material in the preparation of high-end fragrances, so it is widely used in the preparation of assimilated products such as shampoo and hair care products, high-end perfumes, various soaps, detergents, scented powders, and personal care products. Cyclopentadecalactone can also be used as a food additive. When used in food flavors, it can be used together with general macrolides and can achieve better results. Since it can improve the palatability of food, increase people's appetite, and is harmless to health, it is widely used in food flavors such as nuts, vanilla, berries, western wine, and pastries.

[0003] Since the natural source of pentadecalactone is relatively scarce, the pentadecalactone currently sold on the market is mainly obtained by chemical synthesis. At present, only a few foreign countries can carry out small-scale production of pentadecalactone, and the price is very expensive. The process of synthesizing pentadecalactone fragrance is relatively complicated, with many operating steps, and using various solvents such as benzene or toluene. In the production process, it is inevitable to produce some wastewater that is difficult to treat, such as high CODcr concentration, high salt content, high toluene content, and dark color. Therefore, the development of an environmentally friendly pentadecalactone production process has extremely important economic value and social benefits.

[0004] The production of cyclopentadecalactone fragrance belongs to typical fine chemical production, and fine chemical wastewater has the characteristics of large discharge volume, high CODcr concentration, deep chroma, high toxicity, complex pollutant composition, and difficulty in biodegradation. Cyclopentadecalactone fragrance uses toluene as a solvent and produces wastewater containing a high content of acetic acid or acetate in the production process. The discharged wastewater mainly includes: light blue process wastewater produced by hydrolysis of the addition ester process, the main pollutants are toluene, cyclic ketone organic matter, ester organic matter, sodium acetate, etc., reddish brown process wastewater produced by the oxidation process, the main pollutants are toluene, cyclic ketone organic matter, ether organic matter, acetic acid, etc., and dark blue process wastewater produced by the decomposition and neutralization process, the main pollutants are toluene, sodium acetate, etc. At present, for the process wastewater with high toluene content, high salt content, and high CODcr concentration produced by cyclopentadecalactone, the treatment of this type of wastewater is often to reduce the salt content of the wastewater by dilution. The discharge of wastewater with reduced salt content will not only cause environmental deterioration, but also lead to salinization of soil and watershed. In addition, the organic matter in the wastewater contains benzene ring organic matter, which has poor biodegradability, high biological toxicity, and great environmental safety risks, and even affects people's daily life. There are also processes that use triple-effect evaporation for pretreatment and then combine with biochemical comprehensive treatment to treat this part of the process wastewater. However, the brine concentration in these conventional treatment methods cannot be too high, and the energy consumption is high when applied, and the treatment cost is too high, so they cannot meet the needs of wastewater treatment. Summary of the invention

[0005] In order to solve the problems raised by the above background technology, the present invention proposes a method and device for comprehensive utilization of wastewater treatment resources in the production of cyclopentadecalactone fragrances.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] S1, neutralizing acetic acid wastewater: separately collecting acetic acid wastewater from the oxidation process in the production process of cyclopentadecalactone, adding sodium hydroxide solution to neutralize acetic acid until the pH value of the wastewater is 7-9, thereby forming wastewater containing sodium acetate;

[0008] S2, low-temperature vacuum evaporation: other salt-containing and high-toluene content wastewater generated in the production process of cyclopentadecalactone and the neutralized acetic acid wastewater generated in step S1 are combined and pumped into a low-temperature vacuum evaporator, the boiling point is reduced under low vacuum conditions, and then the difference in boiling points between water and other organic matter is used to evaporate and condense under low temperature conditions to separate water from other organic matter, thereby obtaining evaporated condensed water and concentrated waste liquid;

[0009] S3, evaporation condensation water application: the evaporation condensation water obtained in step S2 is collected and used to replace the clean water used in the production process of cyclopentadecalactone for washing and washing;

[0010] S4, evaporation of concentrated liquid solid-liquid separation: the concentrated waste liquid obtained in step S2 is transferred into a solid-liquid separation tank for separation of the solid phase and the liquid phase, and the sodium acetate solid crystals containing three crystal waters and the organic matter concentrated liquid are collected respectively;

[0011] S5, distillation and recovery of concentrated liquid: the concentrated organic liquid collected in step S4 is transferred to a fractionation kettle, and toluene is recovered under negative pressure under low vacuum conditions, and the bottom of the kettle is sent to a waste liquid incinerator for incineration;

[0012] S6. Sodium acetate solid crystallization, recrystallization and reuse: The sodium acetate solid obtained in step S4 is recrystallized by adding ethanol, and a centrifuge is used for solid-liquid separation to obtain sodium acetate and mother liquor respectively, and the centrifuged mother liquor is distilled to recover ethanol for reuse, and the sodium acetate is reused as a raw material for the cyclopentadecalactone addition ester process.

[0013] As a further preferred embodiment of the present technical solution: the volume fraction of the sodium hydroxide solution in step S1 is 30%.

[0014] As a further preferred embodiment of the present technical solution: in the step S2, the vacuum condition is 1000 Pa, and the low temperature condition is 28°C to 38°C.

[0015] As a further preferred embodiment of the present technical solution: in the step S5, the temperature of the fractionation kettle is 60°C to 80°C, and the low vacuum condition is 33333Pa.

[0016] As a further preferred embodiment of the present technical solution: the temperature for recovering ethanol in step S6 is 75°C to 80°C.

[0017] As a further preferred embodiment of the present technical solution: comprising a pretreatment neutralization kettle, an acid wastewater high-level tank and a 30% sodium hydroxide solution high-level tank, wherein the acid wastewater high-level tank and the 30% sodium hydroxide solution high-level tank are respectively connected to the pretreatment neutralization kettle through pipelines, and the pretreatment neutralization kettle is also connected to a low-temperature vacuum evaporator through a pipeline, wherein:

[0018] The low-temperature vacuum evaporator comprises an evaporation tank, the evaporation tank is connected to a defoaming agent high-level tank through a pipeline, the evaporation tank is connected to a condensed water receiving tank through a No. 1 condenser, the evaporation tank is also connected to a heater through a concentrated liquid circulation pump, the evaporation tank is connected to a sedimentation tank through a concentrated liquid discharge pump, and the sedimentation tank is connected to a solid-liquid separation tank through a pipeline.

[0019] As a further preferred embodiment of the present technical solution: the low-temperature vacuum evaporator further comprises a feed proportional valve which is arranged on the pipeline between the pretreatment neutralization kettle and the low-temperature vacuum evaporator and is used to control the flow rate of wastewater entering the low-temperature vacuum evaporator.

[0020] As a further preferred embodiment of the present technical solution: the condensed water receiving tank is connected to the condensed water storage tank through a pipeline, the solid-liquid separation tank is connected to the crystallization kettle through a pipeline, the crystallization kettle is respectively connected to the ethanol high-level tank and the centrifuge through pipelines, the centrifuge is connected to the mother liquid tank through a pipeline, the mother liquid tank is connected to the flash kettle through a pipeline, the flash kettle is connected to the ethanol receiving tank through the No. 2 condenser, and the ethanol receiving tank is connected to the ethanol high-level tank through a pipeline.

[0021] As a further preferred embodiment of the present technical solution: the sedimentation tank and the solid-liquid separation tank are connected to a fractionation kettle via a pipeline.

[0022] As a further preferred embodiment of the present technical solution: the distillation kettle is connected to a toluene vacuum receiving tank via a spiral plate heat exchanger, and the toluene vacuum receiving tank is connected to a toluene temporary storage tank via a pipeline.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. In the present invention, valuable resources such as sodium acetate, toluene and ethanol are recovered from the wastewater of cyclopentadecalactone fragrance production. After sodium acetate is recrystallized, high-purity sodium acetate monohydrate is obtained, which can be directly reused as a raw material for the cyclopentadecalactone addition ester process, greatly reducing the production cost. At the same time, toluene and ethanol are also successfully applied to the production process through negative pressure recovery and normal pressure recovery, realizing the maximum utilization of resources.

[0025] 2. In the present invention, the effluent water quality of the wastewater treated by the method is significantly improved, and the CODcr content, toluene content and TOC content of the evaporated condensed water are far lower than the relevant environmental protection standards, reaching the standards of high-quality water resources, and can be directly used in the washing and cleaning processes in the production process of cyclopentadecalactone, reducing the use of fresh water and reducing water resource consumption. In addition, the waste liquid that cannot be reused is transferred to the waste liquid incinerator for incineration treatment, ensuring that all wastes are properly handled and avoiding the risk of environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the device for comprehensive utilization of wastewater treatment resources in the production of cyclopentadecalactone fragrances.

[0027] Legend: 1. Pretreatment neutralization kettle; 2. Acid wastewater high-level tank; 3. 30% sodium hydroxide high-level tank; 4. Defoaming agent high-level tank; 5. Low-temperature vacuum evaporator; 5-1. Feed proportion valve; 5-2. Evaporation tank; 5-3. Heater; 5-4. Concentrate circulation pump; 5-5. Condenser No. 1; 5-6. Condensate receiving tank; 5-7. Concentrate discharge pump; 5-8. Sedimentation tank; 5-9. Solid-liquid separation tank; 6. Condensate storage tank; 7. Crystallization kettle; 8. Ethanol high-level tank; 9. Centrifuge; 10. Mother liquor tank; 11. Flash kettle; 12. Condenser No. 2; 13. Ethanol receiving tank; 14. Fractionation kettle; 15. Spiral plate heat exchanger; 16. Toluene vacuum receiving tank; 17. Toluene temporary storage tank. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1The present application provides a method and device for comprehensive utilization of wastewater treatment resources in the production of cyclopentadecalactone fragrances, comprising a pretreatment neutralization kettle 1, an acid-containing wastewater high-level tank 2 and a 30% sodium hydroxide solution high-level tank 3, and the acid-containing wastewater high-level tank 2 and the 30% sodium hydroxide solution high-level tank 3 are respectively connected to the pretreatment neutralization kettle 1 through pipelines, and the pretreatment neutralization kettle 1 is also connected to a low-temperature vacuum evaporator 5 through a pipeline, wherein the low-temperature vacuum evaporator 5 comprises an evaporation tank 5-2, and the evaporation tank 5-2 is connected to a defoaming agent high-level tank 4 through a pipeline, and the evaporation tank 5-2 is connected to a condensate receiving tank 5-6 through a No. 1 condenser 5-5, and the evaporation tank 5-2 is also connected to a heater 5-3 through a concentrated liquid circulation pump 5-4, and the evaporation tank 5-2 is connected to a sedimentation tank 5-8 through a concentrated liquid discharge pump 5-7, and the sedimentation tank 5-8 is connected to a solid-liquid separation tank 5-9 through a pipeline, and the low-temperature vacuum evaporator 5 also includes A feed proportion valve 5-1 is arranged on the pipeline between the pretreatment neutralization kettle 1 and the low-temperature vacuum evaporator 5 and is used to control the flow rate of wastewater entering the low-temperature vacuum evaporator 5. The condensed water receiving tank 5-6 is connected to the condensed water storage tank 6 through a pipeline. The solid-liquid separation tank 5-9 is connected to the crystallization kettle 7 through a pipeline. The crystallization kettle 7 is respectively connected to the ethanol high-level tank 8 and the centrifuge 9 through pipelines. The centrifuge 9 is connected to the mother liquid tank 10 through a pipeline. The mother liquid tank 10 is connected to the flash kettle 11 through a pipeline. The flash kettle 11 is connected to the ethanol receiving tank 13 through the second condenser 12, and the ethanol receiving tank 13 is connected to the ethanol high-level tank 8 through a pipeline. The sedimentation tank 5-8 and the solid-liquid separation tank 5-9 are jointly connected to the fractionation kettle 14 through a pipeline. The fractionation kettle 14 is connected to the toluene vacuum receiving tank 16 through the spiral plate heat exchanger 15, and the toluene vacuum receiving tank 16 is connected to the toluene temporary storage tank 17 through a pipeline.

[0030] Specifically, the acidic wastewater containing acetic acid in the oxidation process of the cyclopentadecalactone fragrance production process collected separately is put into the neutralization pretreatment kettle 1, stirring is started, and 30% sodium hydroxide solution is slowly added to the neutralization pretreatment kettle 1 from the sodium hydroxide high-level tank 3, and the wastewater is neutralized until the pH value of the wastewater is detected to be 7-9 as the end point, forming organic wastewater containing sodium acetate salts, and then the salt-containing and high-toluene content wastewater generated in the addition process and the decomposition and neutralization process in the production process of cyclopentadecalactone is collected, and then transferred from the production workshop wastewater collection pool to the neutralization pretreatment kettle 1 by a pump, and mixed evenly with the neutralized acetic acid wastewater generated above, and then transported to the evaporation tank 5-2 of the low-temperature vacuum evaporator 5 by a metering pump through a feed proportion valve. At the same time, the defoaming agent is metered into the evaporation tank 5-2 from the defoaming agent high-level tank 4 to prevent the generation of a large amount of foam. Under the conditions of 1000Pa high vacuum and 28-38°C low temperature, evaporation and condensation are carried out. The water phase is condensed by the No. 1 condenser 5-5 to obtain evaporated condensed water of the water phase. The tank bottom is transferred to the heater 5-3 through the concentrate circulation pump 5-4 for heating and then refluxed to the evaporation tank 5-2 for evaporation and concentration to obtain concentrated waste liquid of the organic phase. Then, the obtained evaporated condensed water is collected and transferred to the condensed water storage tank 6 through the condensed water receiving tank 5-6 for use in the water washing and washing processes in the production process of cyclopentadecalactone. Then, the obtained concentrated waste liquid is transferred to the low-temperature vacuum evaporator through the concentrate discharge pump 5-7. 5 is initially separated in the settling tank 5-8, and then transferred to the solid-liquid separation tank 5-9 for solid-liquid separation, respectively obtaining sodium acetate solid containing crystal water and organic concentrated liquid; respectively transferred to the recrystallization kettle 7 and the fractionation kettle 14, and the collected organic concentrated liquid is transferred to the fractionation kettle 14, the steam valve of the fractionation kettle 14 is opened to heat to 60-80°C, toluene is recovered under negative pressure under the low vacuum condition of 33333Pa, and toluene is collected when the temperature at the top of the tower drops or no material is discharged. The recovered toluene is condensed by the spiral plate heat exchanger 15, recovered by the toluene vacuum receiving tank 16, and transferred to the toluene temporary storage tank 17 for application, and then metered from the ethanol high-level tank 8 to the recrystallization kettle 7 Ethanol is added into the recrystallization kettle 7, stirring is started, and then the obtained sodium acetate solid is added into the recrystallization kettle 7, the jacket steam valve is opened, the steam in the kettle is condensed by the condenser and then refluxed into the recrystallization kettle 7, and then the cooling water valve is opened to cool down and precipitate crystals, the mother liquid tank 10 is evacuated, the recrystallized solid-liquid mixture is transferred to the centrifuge 9, and the centrifuge 9 is started for solid-liquid separation, and finally, the mother liquor separated from the solid and liquid is transferred to the flash kettle 11 through the mother liquid tank 10, and ethanol is recovered at normal pressure under the condition of 75-80°C for application, and the ethanol is condensed by the second condenser 12 and transferred to the ethanol high-level tank 8 through the ethanol receiving tank 13 for application, and the solid crystals are left in the centrifuge 9 to obtain sodium acetate, which is used for the raw material sodium acetate of the cyclopentadecalactone addition ester process for reuse.

[0031] In summary, the physical and chemical means were used for quality separation and extraction, and the evaporation condensate water quality collected from the effluent was tested. The CODcr content was 20.3 mg / L, the toluene content was 0.15 mg / L, and the TOC content was 5-10 mg / L. The sodium acetate obtained by recrystallization was tested to contain 1 crystal water, and the content of sodium acetate monohydrate was 98.1%. Not only did it achieve the wastewater discharge standard, but it also recycled resources, reduced the energy consumption of wastewater treatment, and was not limited by the brine concentration.

[0032] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for comprehensive utilization of wastewater treatment resources in the production of cyclopentadecalactone fragrances, characterized in that: The specific steps include: S1, neutralizing acetic acid wastewater: separately collecting acetic acid wastewater from the oxidation process in the production process of cyclopentadecalactone, adding sodium hydroxide solution to neutralize acetic acid until the pH value of the wastewater is 7-9, thereby forming wastewater containing sodium acetate; S2, low-temperature vacuum evaporation: other salt-containing and high-toluene content wastewater generated in the production process of cyclopentadecalactone and the neutralized acetic acid wastewater generated in step S1 are combined and pumped into a low-temperature vacuum evaporator (5), the boiling point is reduced under low vacuum conditions, and then the difference in boiling points between water and other organic matter is used to evaporate and condense under low temperature conditions to separate water from other organic matter, thereby obtaining evaporated condensed water and concentrated waste liquid; S3, evaporation condensation water application: the evaporation condensation water obtained in step S2 is collected and used to replace the clean water used in the production process of cyclopentadecalactone for washing and washing; S4, evaporation of concentrated liquid solid-liquid separation: the concentrated waste liquid obtained in step S2 is transferred into a solid-liquid separation tank (5-9) for separation of the solid phase and the liquid phase, and the sodium acetate solid crystals containing three crystal waters and the organic matter concentrated liquid are collected respectively; S5, distilling and recovering the concentrated liquid: the concentrated organic liquid collected in step S4 is transferred to a fractionation kettle (14), and toluene is recovered under negative pressure under low vacuum conditions, and the bottom of the kettle is sent to a waste liquid incinerator for incineration; S6. Sodium acetate solid crystallization, recrystallization and reuse: The sodium acetate solid obtained in step S4 is recrystallized by adding ethanol, and a centrifuge (9) is used for solid-liquid separation to obtain sodium acetate and mother liquor respectively. The centrifuged mother liquor is distilled to recover ethanol for reuse, and the sodium acetate is reused as a raw material for the cyclopentadecalactone addition ester process.

2. The method for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 1, characterized in that: The volume fraction of the sodium hydroxide solution in step S1 is 30%.

3. The method for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 2, characterized in that: In step S2, the vacuum condition is 1000 Pa, and the low temperature condition is 28° C. to 38° C.

4. The method for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 3, characterized in that: In the step S5, the temperature of the fractionation reactor (14) is 60°C to 80°C, and the low vacuum condition is 33333Pa.

5. The method for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 4, characterized in that: The temperature for recovering ethanol in step S6 is 75°C to 80°C.

6. The device for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 5, characterized in that: The invention comprises a pretreatment neutralization kettle (1), an acid wastewater high-level tank (2) and a 30% sodium hydroxide solution high-level tank (3), wherein the acid wastewater high-level tank (2) and the 30% sodium hydroxide solution high-level tank (3) are respectively connected to the pretreatment neutralization kettle (1) through pipelines, and the pretreatment neutralization kettle (1) is also connected to a low-temperature vacuum evaporator (5) through a pipeline, wherein: The low-temperature vacuum evaporator (5) comprises an evaporation tank (5-2), the evaporation tank (5-2) is connected to a defoaming agent high-level tank (4) via a pipeline, the evaporation tank (5-2) is connected to a condensed water receiving tank (5-6) via a No. 1 condenser (5-5), the evaporation tank (5-2) is also connected to a heater (5-3) via a concentrated liquid circulation pump (5-4), the evaporation tank (5-2) is connected to a sedimentation tank (5-8) via a concentrated liquid discharge pump (5-7), and the sedimentation tank (5-8) is connected to a solid-liquid separation tank (5-9) via a pipeline.

7. The device for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 6, characterized in that: The low-temperature vacuum evaporator (5) further comprises a feed proportional valve (5-1) which is arranged on a pipeline between the pretreatment reactor (1) and the low-temperature vacuum evaporator (5) and is used to control the flow rate of wastewater entering the low-temperature vacuum evaporator (5).

8. The device for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 7, characterized in that: The condensed water receiving tank (5-6) is connected to the condensed water storage tank (6) through a pipeline, the solid-liquid separation tank (5-9) is connected to the crystallization kettle (7) through a pipeline, the crystallization kettle (7) is connected to the ethanol high-level tank (8) and the centrifuge (9) through pipelines, respectively, the centrifuge (9) is connected to the mother liquid tank (10) through a pipeline, the mother liquid tank (10) is connected to the flash kettle (11) through a pipeline, the flash kettle (11) is connected to the ethanol receiving tank (13) through the second condenser (12), and the ethanol receiving tank (13) is connected to the ethanol high-level tank (8) through a pipeline.

9. The device for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 8, characterized in that: The sedimentation tank (5-8) and the solid-liquid separation tank (5-9) are connected to a fractionation kettle (14) via a pipeline.

10. The device for comprehensive utilization of wastewater treatment resources of cyclopentadecalactone fragrance production according to claim 9, characterized in that: The fractionation kettle (14) is connected to a toluene vacuum receiving tank (16) via a spiral plate heat exchanger (15), and the toluene vacuum receiving tank (16) is connected to a toluene temporary storage tank (17) via a pipeline.

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