Treatment method and application of methyl cyclopentenolone wastewater

Abstract

The invention belongs to the technical field of production of methyl cyclopentenolone, and discloses a treatment method and application of methyl cyclopentenolone wastewater. The treatment method comprises the following steps: S1, adding a decolorizing agent into the yellow fine mother solution for decolorizing, and carrying out solid-liquid separation to obtain a treatment solution; s2, an extracting agent is added into the treating fluid obtained in the step S1 for extraction and impurity removal, and extract liquor is obtained; s3, adding alkali liquor into the extract obtained in the step S2 for hydrolysis, and distilling to obtain a dimethylamine aqueous solution; s4, rectifying the dimethylamine aqueous solution obtained in the step S3 to obtain dimethylamine and residual liquid; and S5, adding sulfuric acid into the residual liquid obtained in the step S4 to obtain sulfate. According to the method, the yellow fine mother liquor is subjected to decoloration and impurity removal and then is subjected to alkaline hydrolysis to recover dimethylamine, so that the generation of wastewater can be effectively reduced, the consumption of raw materials is reduced, and cost reduction and efficiency improvement are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of methylcyclopentenolone production, and in particular relates to a method for treating methylcyclopentenolone wastewater and application thereof. Background Art

[0002] Methylcyclopentenolone is a edible flavoring, but a large amount of high-salt and high-ammonia nitrogen wastewater is produced during its production. At present, the treatment of high-salt and high-ammonia nitrogen wastewater is a global problem. Most of the current sewage treatment plants use dilution biological treatment, which is low-cost and does not cause secondary pollution, but is limited by its poor treatment capacity and is far from meeting the production needs of chemical companies. Another method is evaporation treatment, which can meet the needs of a certain scale of chemical production, but the process requires too high energy consumption, the cost is too high, and the waste residue generated is also difficult to treat, causing secondary pollution.

[0003] Chinese invention patent 201410501487.1 discloses a method for treating high-ammonia nitrogen mother liquor wastewater in the production of methylcyclopentenolone, wherein the high-ammonia nitrogen mother liquor is separated into an aqueous phase and an organic phase by an extractant; the organic phase is distilled and condensed to recycle the extractant and recover the methylcyclopentenolone; the aqueous phase is decolorized, distilled and crystallized to recover dimethylamine hydrochloride and continue to be put into production, and the steam used for distillation is waste heat tail gas. The invention can effectively recover the crude methylcyclopentenolone, and at the same time use the waste heat tail gas to evaporate the wastewater and recover dimethylamine hydrochloride, achieving multiple effects of cleaning, environmental protection, and resource recycling.

[0004] Chinese invention patent 201610751006.1 discloses a method for recovering dimethylamine in MCP hydrolysis mother liquor, comprising the following steps: a. The yellow fine mother liquor separated from the centrifuge is vacuum pumped to the distillation kettle; b. Alkali liquor is added, and the yellow fine mother liquor and liquid alkali solution are in a ratio of 1:3, stirring is started, steam heating and reduced pressure distillation is started, and the kettle temperature is evaporated to 92°C. The evaporated gas phase dimethylamine is liquefied into a low-concentration dimethylamine aqueous solution through a condensation absorption tower; C. After the dimethylamine solution in the condensation absorption tower reaches the concentration of 32% required for production, it is pumped into the high-level tank of the raw material at the post for standby.

[0005] Chinese invention patent 202311592680.6 discloses a method for recycling dimethylamine hydrochloride from methylcyclopentenolone wastewater, the method comprising the following steps: step 1: collecting the methylcyclopentenolone wastewater and sending it into a color kettle, adding activated carbon, stirring for decolorization, and removing the activated carbon by centrifugation to obtain decolorized methylcyclopentenolone wastewater; step 2: transferring the decolorized methylcyclopentenolone wastewater obtained in step 1 into a salt-forming kettle for concentration to obtain a concentrated ammonium salt solution, cooling and crystallizing to obtain dimethylamine hydrochloride crystals, and adding an equal amount of formaldehyde to the recovered dimethylamine hydrochloride, and then pumping it into an amination kettle for application to make The wastewater can be fully utilized.

[0006] At present, the production cost of methylcyclopentenolone is high, the efficiency is low, and the high-salt wastewater produced is large and difficult to treat, which restricts the development of this product. Therefore, there is an urgent need for a methylcyclopentenolone wastewater process that can reduce costs and increase efficiency. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for treating methylcyclopentenolone wastewater and application thereof.

[0008] In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for treating methylcyclopentenolone wastewater, comprising the following steps: S1, adding a decolorizing agent to the yellow fine mother liquor for decolorization, solid-liquid separation, and obtaining a treated liquid; S2, adding an extractant to the treated liquid obtained in step S1 to extract and remove impurities to obtain an extract; S3, adding alkali solution to the extract obtained in step S2 for hydrolysis and distillation to obtain a dimethylamine aqueous solution; S4, distilling the dimethylamine aqueous solution obtained in step S3 to obtain dimethylamine and a residual liquid; S5. Add sulfuric acid to the residual liquid obtained in step S4 to obtain sulfate.

[0009] Furthermore, the decolorizing agent in step S1 is activated carbon.

[0010] Furthermore, the ratio of the decolorizing agent to the yellow fine mother liquor in step S1 is 8-12 kg: 2 m 3 , preferably 10kg:2m 3 .

[0011] Furthermore, the decolorization in step S1 is performed by stirring at 60-85°C for 1-5h, preferably at 80°C for 2h.

[0012] Furthermore, the solid-liquid separation in step S1 includes at least one of filtration, centrifugation and filter pressing; preferably filter pressing.

[0013] Furthermore, the extractant in step S2 is an organic solvent, preferably toluene and / or chloroform.

[0014] Furthermore, the ratio of the extractant to the treatment liquid in step S2 is 100L:0.5-0.9m 3 , preferably 100L:0.7m 3 .

[0015] Furthermore, the extraction time in step S2 is 2-4 hours, preferably 3 hours.

[0016] Furthermore, the alkali in step S3 is at least one of quicklime, sodium hydroxide and potassium hydroxide; the mass concentration of the alkali solution is 20-40%; preferably 32%.

[0017] Furthermore, the ratio of the alkali solution to the extract in step S3 is 0.2-0.4 m 3 : 100L; preferably 0.3m 3 :100L.

[0018] Furthermore, the distillation conditions in step S4 are: temperature 90° C., time 5 h.

[0019] Furthermore, the mass concentration of sulfuric acid in step S5 is 15%.

[0020] Furthermore, in step S5, the ratio of sulfuric acid to residual liquid is 1.5:1.

[0021] In a second aspect, the present invention provides a method for recovering dimethylamine from MCP high-salt wastewater, which is recovered from yellow fine mother liquor using the above-mentioned treatment method.

[0022] In a third aspect, the present invention provides application of the above-mentioned treatment method in the production of dimethylamine.

[0023] In a fourth aspect, the present invention provides application of the above-mentioned treatment method in the production of methylcyclopentenolone.

[0024] Compared with the prior art, the present invention has the following beneficial effects: The invention can effectively reduce the generation of waste water, reduce the consumption of raw materials, and achieve cost reduction and efficiency improvement by decolorizing and removing impurities from the yellow sludge mother liquor and then performing alkaline hydrolysis to recover dimethylamine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention in conjunction with specific examples. Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0027] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0028] The treatment method of the present invention comprises a decolorizing kettle, an extraction kettle, an alkaline hydrolysis kettle and a distillation tower connected in sequence, such as Figure 1 shown.

[0029] In some specific embodiments, the treatment method comprises the following steps: S1. Pump the yellow fine mother liquor into the decolorization tank, add decolorizer to decolorize, and filter through a filter press to obtain a treated liquid; S2, transferring the treated liquid into an extraction kettle, adding an extractant to extract and remove impurities, and performing phase separation to obtain an aqueous phase; S3, transferring the aqueous phase into an alkaline hydrolysis kettle, adding alkali solution for hydrolysis and distillation to obtain a dimethylamine aqueous solution; S4, transferring the dimethylamine aqueous solution obtained in step S3 into a distillation tower for rectification to obtain dimethylamine and a residual liquid; S5. Add sulfuric acid to the residual liquid in the alkaline hydrolysis kettle to obtain sulfate.

[0030] In some embodiments, the decolorizing agent in step S1 is activated carbon; the ratio of the decolorizing agent to the yellow fine mother liquor is 8-12 kg: 2 m 3 , preferably 10kg:2m 3 The decolorization step is: stirring at 60-85°C for 1-5h, preferably stirring at 80°C for 2h.

[0031] In some embodiments, the extractant in step S2 is an organic solvent, preferably toluene and / or chloroform; the ratio of the extractant to the treatment liquid is 100L:0.5-0.9m 3 , preferably 100L:0.7m 3 ; The extraction time is 2-4h, preferably 3h.

[0032] In some embodiments, the alkali in step S3 is at least one of quicklime, sodium hydroxide, and potassium hydroxide; the mass concentration of the alkali solution is 20-40%; preferably 32%; the ratio of the alkali solution to the extract is 0.2-0.4m 3 : 100L; preferably 0.3m 3 :100L.

[0033] In some embodiments, the distillation conditions in step S4 are: temperature 90° C., time 5 h.

[0034] In some embodiments, the mass concentration of the sulfuric acid in step S5 is 15%; the ratio of the sulfuric acid to the residual liquid is 1.5:1.

[0035] Example 1 A method for treating methylcyclopentenolone wastewater comprises the following steps: Transfer 2m³ of yellow fine mother liquor into the decolorization tank by pump, add 10kg of activated carbon, decolorize and stir at 80℃ for 2h, then filter through filter press to obtain filtrate.

[0036] The decolorized yellow fine mother liquor (2 m³) was transferred to the extraction kettle, 200 L of toluene was added to the extraction kettle, and the mixture was fully stirred and extracted for 3 h before phase separation to obtain the aqueous phase.

[0037] The aqueous phase (1.8 m³) was transferred to the alkaline hydrolysis kettle, and 500 L of liquid alkali (32%) was added. After sufficient reaction, the dimethylamine aqueous solution was distilled (temperature 95°C, time 8h).

[0038] The aqueous solution is then rectified by a distillation tower (distillation temperature is 90°C, distillation time is 8 hours) to purify refined dimethylamine (yield 95%, purity 32.4%).

[0039] Add 500L of dilute sulfuric acid (concentration 25wt%) to the remaining residual liquid (0.75 m³) in the alkaline hydrolysis kettle to extract sulfate.

[0040] Example 2 A method for treating methylcyclopentenolone wastewater comprises the following steps: 3m³ of yellow fine mother liquor was transferred into the decolorization tank by pump, 10kg of activated carbon was added to decolorize at 80℃ and stirred for 2h, then filtered through a filter press to obtain the filtrate.

[0041] The decolorized yellow fine mother liquor (3 m³) was transferred to the extraction kettle, 200 L of toluene was added to the extraction kettle, and the mixture was fully stirred and extracted for 3 h before phase separation to obtain the aqueous phase.

[0042] The aqueous phase (2.9 m³) was transferred to the alkaline hydrolysis kettle, and 700 L of liquid alkali (32%) was added. After sufficient reaction, the dimethylamine aqueous solution was distilled (temperature 95°C, time 8h).

[0043] The aqueous solution is then rectified by a distillation tower (distillation temperature is 90°C, distillation time is 8 hours) to purify refined dimethylamine (yield 94.5%, purity 32.3%).

[0044] Add 750L of dilute sulfuric acid (concentration 25wt%) to the remaining residual liquid (1 m³) in the alkaline hydrolysis kettle to extract sulfate.

[0045] Example 3 A method for treating methylcyclopentenolone wastewater comprises the following steps: Transfer 2m³ of yellow fine mother liquor into the decolorization tank by pump, add 15kg of activated carbon, decolorize and stir at 80℃ for 1h, then filter through filter press to obtain filtrate.

[0046] The decolorized yellow fine mother liquor (2 m³) was transferred to the extraction kettle, 300 L of toluene was added to the extraction kettle, and the mixture was fully stirred and extracted for 2 h before phase separation to obtain the aqueous phase.

[0047] The water phase (1.9 m³) was transferred to the alkaline hydrolysis kettle, and 500 L of liquid alkali (32%) was added. After sufficient reaction, the dimethylamine aqueous solution was distilled (temperature 95°C, time 6h).

[0048] The aqueous solution is then rectified by a distillation tower (distillation temperature is 90°C, distillation time is 8 hours) to purify refined dimethylamine (yield 95.5%, purity 32.4%).

[0049] Add 500L of dilute sulfuric acid (concentration 25wt%) to the remaining residual liquid (0.75 m³) in the alkaline hydrolysis kettle to extract sulfate.

[0050] The above is a further description of the present invention in conjunction with specific embodiments, but these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

Claims

1. A method for treating methylcyclopentenolone wastewater, characterized in that: The steps include: S1, adding a decolorizing agent to the yellow fine mother liquor for decolorization, solid-liquid separation, and obtaining a treated liquid; S2, adding an extractant to the treated liquid obtained in step S1 to extract and remove impurities to obtain an extract; S3, adding alkali solution to the extract obtained in step S2 for hydrolysis and distillation to obtain a dimethylamine aqueous solution; S4, distilling the dimethylamine aqueous solution obtained in step S3 to obtain dimethylamine and a residual liquid; S5. Add sulfuric acid to the residual solution obtained in step S4 to obtain sulfate.

2. The processing method according to claim 1, characterized in that: The ratio of the decolorizing agent to the yellow fine mother liquor in step S1 is 8-12kg:2m 3 ; and / or The decolorization in step S1 is: stirring at 60-85°C for 1-5h; and / or The solid-liquid separation in step S1 includes at least one of filtration, centrifugation and filter pressing.

3. The processing method according to claim 1, characterized in that: The ratio of the extractant to the treatment liquid in step S2 is 100L:0.5-0.9m 3 ; and / or The extraction time is 2-4h.

4. The processing method according to claim 1, characterized in that: The alkali in step S3 is at least one of quicklime, sodium hydroxide and potassium hydroxide; and / or The mass concentration of the alkali solution is 20-40%; and / or The ratio of the alkali solution to the extract is 0.2-0.4m 3 :100L.

5. The processing method according to claim 1, characterized in that: The distillation conditions in step S4 are: temperature 85°C-95°C, time 5-8h.

6. The processing method according to claim 1, characterized in that: The mass concentration of sulfuric acid in step S5 is 15%, and / or The ratio of the sulfuric acid to the residual liquid is 1.5:

1.

7. The processing method according to any one of claims 1 to 6, characterized in that: The invention comprises a decolorizing kettle, an extraction kettle, an alkaline hydrolysis kettle and a distillation tower which are connected in sequence.

8. A method for recovering dimethylamine, characterized in that: Recover from yellow fine mother liquor using the treatment method described in any one of claims 1 to 7.

9. Use of the treatment method according to any one of claims 1 to 7 in the production of dimethylamine.

10. Use of the treatment method according to any one of claims 1 to 7 in the production of methylcyclopentenolone.

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