Recycling method of byproduct ethyl 3-ethoxypropionate in alpha-keto acid production
Through the method of α-ketone acid production, the method of separating the use of normal pressure division, refined distillation and covalent characteristics of 3-ethyl oxygenate solves the problem of recycling and utilization in existing technologies Resource recovery and cost reduction.
Patent Information
- Application Number
- CN202411432262.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-01-21
AI Technical Summary
In the prior art, the recycling cost of ethyl 3-ethoxypropionate by-product in the α-keto acid production process is relatively high, and it is difficult to effectively reduce production energy consumption and material consumption.
Through the use of liquids for normal pressure division and refined distillation, the co-boiling characteristics of ethanol, water, and acrylic ethyls are used to separate 3-ethyl oxydate ethyls of acerite, and the purity is 99.5% through septum and drying treatment. The above 3-ethylopenate products.
This method not only reduces the cost of three-waste treatment and environmental protection costs, but also can effectively recover economically valuable ethyl 3-ethoxypropionate, realizes the resource utilization of waste, and is suitable for large-scale production.
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Figure CN119330828A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method technology for recycling by-product 3-ethoxypropionate, and specifically to a method for recycling by-product 3-ethoxypropionate in alpha-keto acid production. Background Art
[0002] It is well known that α-keto acid is an important intermediate for preparing L-phosphinothricin ammonium, and wastewater containing ethyl 3-ethoxypropionate is produced during its synthesis process. The components in the wastewater are relatively simple. In addition to ethyl 3-ethoxypropionate, there are also a small amount of ethyl acrylate, ethanol and a large amount of water. The specific composition is 3-ethoxypropionic acid ethyl ester 3-5%, ethanol 25-30%, ethyl acrylate 0.5-1%, and the rest is water. There is a high recovery value, and in recent years, the domestic and foreign production capacity release of the L-phosphinothricin ammonium industry has increased sharply, and the competitive pressure is high. Domestic and foreign scientific research is committed to studying how to reduce the production energy consumption and material consumption of L-phosphinothricin ammonium, so the resource utilization of by-products and three wastes in the production process is one of the main research and development directions.
[0003] Ethyl 3-ethoxypropionate is a colorless transparent liquid with a density of 0.951 g / mL, a melting point of -75°C, a boiling point of 169.1°C, and a water solubility of 1.6 g / 100 mL. It is a high-performance, low-volatility ether ester solvent with excellent solubility for many coating resins. It is mainly used in automotive original paint, automotive repair paint, iron printing paint, electrostatic spray paint, ship paint, leather paint, resin solvent, and electronic product solvent.
[0004] In the prior art, the cost of recycling ethyl 3-ethoxypropionate is relatively high. In view of the potential value and wide application of ethyl 3-ethoxypropionate, it is necessary to seek a more economical recycling method to efficiently recover the valuable components in the produced fluid, so as to reduce and offset the cost of the product and improve the market competitiveness of the product. Summary of the invention
[0005] The purpose of the present invention is to provide a method for recycling ethyl 3-ethoxypropionate produced as a by-product in the production of α-keto acid, so as to solve the above-mentioned shortcomings in the prior art.
[0006] In order to achieve the above object, the present invention provides the following technical solution: comprising the following steps: S1: The collected produced liquid is subjected to simple atmospheric pressure fractionation, the purpose of which is to further concentrate the by-products and obtain the ethanol-rich component I. After fractionation, the mixed solution of ethanol and ethyl acrylate is obtained, which can be directly applied after GC quantification; S2: The residual liquid after fractionation is sent to a distillation tower for atmospheric distillation. After separation of the distillate at the top of the tower, an organic phase rich in ethyl 3-ethoxypropionate can be obtained, which is recorded as component II. The water phase is used in the next batch of produced liquid; the bottom of the tower is water, which can be directly used as a recycled water jacket in the production of α-keto acid; S3: Wash component II twice with an appropriate amount of water, and let it stand for separation to obtain crude ethyl 3-ethoxypropionate containing trace amounts of water; S4: Drying the crude ethyl 3-ethoxypropionate to obtain ethyl 3-ethoxypropionate product with a purity of more than 99.5%.
[0007] As a further description of the above technical solution: the produced liquid in S1 is produced in the production of α-keto acid, and its composition is 3-5% ethyl 3-ethoxypropionate, 25-30% ethanol, 0.5-1% ethyl acrylate, and the rest is water.
[0008] As a further description of the above technical solution: the composition of component I in S1 is: 60-70% ethanol, 2-3% ethyl acrylate, <0.5% ethyl 3-ethoxypropionate, and the rest is water.
[0009] As a further description of the above technical solution: when the gas phase temperature reaches 80°C during the fractionation in S1, the extraction is stopped, and the extracted volume is about 28-33% of the total volume.
[0010] As a further description of the above technical solution: during the distillation in S2, when the gas phase temperature reaches 85°C, the distillation is stopped, and the extracted volume is about 30-35% of the total volume.
[0011] As a further description of the above technical solution: the composition of component II in S2 is: the normalized content of ethyl 3-ethoxypropionate is 85-90%, the normalized content of ethanol is 10-15%, and the rest is water.
[0012] As a further description of the above technical solution: the composition of the crude ethyl 3-ethoxypropionate obtained after two water washings in S3 is: the qualitative content of ethyl 3-ethoxypropionate is about 99.5%, the content is about 99%, and the water content is within 1%.
[0013] As a further description of the above technical solution: the selected desiccant is a combination of anhydrous sodium sulfate, anhydrous magnesium sulfate, 4A molecular sieve, 732 resin or super absorbent resin.
[0014] The purpose of the present invention is to separate and recycle the valuable components in the produced liquid generated in the production of α-keto acid. In order to solve the technical problem, the present invention is improved on the basis of organic solvent extraction enrichment and distillation, and proposes to use the azeotropic reaction of ethanol, water and ethyl acrylate to first separate ethyl acrylate and most of ethanol, and then use the azeotropic reaction of water and ethyl 3-ethoxypropionate to separate ethyl 3-ethoxypropionate from the system, and then obtain ethyl 3-ethoxypropionate with a content of more than 99.5% through liquid separation and drying.
[0015] The beneficial effects of the present invention are as follows: the by-product recycling method can not only reduce the three waste treatment costs and environmental protection costs, but also obtain 3-ethoxypropionic acid ethyl ester by-product with economic value, which belongs to waste resource utilization, reduces costs and increases efficiency, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.
[0017] Figure 1 A schematic diagram of a flow chart provided for an embodiment of the present invention. DETAILED DESCRIPTION
[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.
[0019] See also Figure 1 The embodiment of the present invention provides a technical solution for the recovery and utilization of ethyl 3-ethoxypropionate produced as a by-product in the production of α-keto acid:
[0020] In another embodiment provided by the present invention, the following steps are included: S1: The collected produced liquid is subjected to simple atmospheric pressure fractionation, the purpose of which is to further concentrate the by-products and obtain the ethanol-rich component I. After fractionation, the mixed solution of ethanol and ethyl acrylate is obtained, which can be directly applied after GC quantification; S2: The residual liquid after fractionation is sent to a distillation tower for atmospheric distillation. After separation of the distillate at the top of the tower, an organic phase rich in ethyl 3-ethoxypropionate can be obtained, which is recorded as component II. The water phase is used in the next batch of produced liquid; the bottom of the tower is water, which can be directly used as a recycled water jacket in the production of α-keto acid; S3: Wash component II twice with an appropriate amount of water, and let it stand for separation to obtain crude ethyl 3-ethoxypropionate containing trace amounts of water; S4: Drying the crude ethyl 3-ethoxypropionate to obtain ethyl 3-ethoxypropionate product with a purity of more than 99.5%.
[0021] In another embodiment provided by the present invention, the produced liquid in S1 is produced in the production of α-keto acid, and its composition is 3-5% ethyl 3-ethoxypropionate, 25-30% ethanol, 0.5-1% ethyl acrylate, and the rest is water.
[0022] In another embodiment provided by the present invention, the composition of component I in S1 is: 60-70% ethanol, 2-3% ethyl acrylate, <0.5% ethyl 3-ethoxypropionate, and the rest is water.
[0023] In another embodiment provided by the present invention, when the gas phase temperature reaches 80° C. during fractionation in S1, the extraction is stopped, and the extracted volume is about 28-33% of the total volume.
[0024] In another embodiment provided by the present invention, when the gas phase temperature reaches 85° C. during the distillation in S2, the distillation is stopped, and the extracted volume is about 30-35% of the total volume.
[0025] In another embodiment provided by the present invention, the composition of component II in S2 is: the normalized content of ethyl 3-ethoxypropionate is 85-90%, the normalized content of ethanol is 10-15%, and the rest is water.
[0026] In another embodiment provided by the present invention, the composition of the crude ethyl 3-ethoxypropionate obtained by washing twice in S3 is as follows: the qualitative content of ethyl 3-ethoxypropionate is about 99.5%, the content is about 99%, and the water content is less than 1%.
[0027] In another embodiment provided by the present invention, the selected desiccant is a combination of anhydrous sodium sulfate, anhydrous magnesium sulfate, 4A molecular sieve, 732 resin or a highly absorbent resin. Example
[0028] In the embodiment, the produced liquid components include 3-ethoxyethyl propionate 3-5%, ethanol 25-30%, ethyl acrylate 0.5-1%, and the remaining substance is water.
[0029] The analysis method adopts the area normalization method of gas chromatography, chromatographic column: HP-5 (30m×0.32mm×0.25μm), injection port temperature 220℃, injection volume: 0.2μL split ratio 10:1, column temperature 60℃, hold for 2min, increase temperature to 200℃ at 10℃ / min and hold for 30min. Carrier gas (N2) flow rate 2mL / min, FID detector temperature 230℃, air flow: 400mL / min, hydrogen flow 30mL / min.
[0030] 800 g of the produced liquid was placed in a four-necked bottle for fractional distillation. The heating was turned on. When the gas phase temperature was about 74°C, production began, and then there was stable production between 76 and 78°C. When the gas phase temperature rose to 80°C, the liquid temperature in the four-necked bottle was 90°C. The fractional distillation operation was stopped, the temperature was lowered, and the distillate was collected and weighed. About 236 g was recorded as component I. Component I was distilled at a reflux ratio of 2:1, and the first 60% of the fraction was cut out and sampled. The composition monitored by GC was: 40% ethanol, 5% ethyl acrylate, no ethyl 3-ethoxypropionate, and water was the balance.
[0031] The residual liquid was put into an intermittent distillation tower, and the heating was turned on for full reflux for 1 hour. The reflux ratio was adjusted to 5:1 to start extraction. When the top temperature reached 85°C, the distillation was stopped and the temperature was lowered. The bottom of the tower was sampled, and the GC monitoring composition was: 0.03% ethanol, no 3-ethoxypropionic acid ethyl ester was detected, and the rest was water; the top distillate weighed 289g, and the liquid was separated by standing. The lower aqueous phase was directly used in the next batch of extracted liquid for further treatment. The upper organic phase was recorded as component II, and the sample was taken. The GC monitoring composition was: 86% 3-ethoxypropionic acid ethyl ester, 10.4% ethanol, and the rest was water.
[0032] Component II was washed with 50g of water twice, and then sampled. The composition of the sample was monitored by GC: 99.7% ethyl 3-ethoxypropionate, 0.01% ethanol, and the rest water. 5g of anhydrous sodium sulfate was added to dry until the water content was ≤0.03%, and the finished product of ethyl 3-ethoxypropionate was obtained. Example
[0033] 800 g of produced liquid was placed in a four-necked bottle for fractional distillation. The heating was turned on. When the gas phase temperature was about 74°C, production began, and then there was stable production between 76 and 78°C. When the gas phase temperature rose to 80°C, the liquid temperature in the four-necked bottle was 90°C. The fractional distillation operation was stopped, the temperature was lowered, and the distillate was collected and weighed. About 280 g was recorded as component I. Component I was distilled at a reflux ratio of 2:1, and the first 60% of the fraction was cut out and sampled. The composition monitored by GC was: 40.8% ethanol, 3.7% ethyl acrylate, 0.5% ethyl 3-ethoxypropionate, and water was the balance.
[0034] The residual liquid was put into an intermittent distillation tower, and the heating was turned on for full reflux for 1 hour. The reflux ratio was adjusted to 5:1 to start extraction. When the top temperature reached 85°C, the distillation was stopped and the temperature was lowered. The bottom of the tower was sampled, and the GC monitoring composition was: 0.02% ethanol, no 3-ethoxypropionic acid ethyl ester was detected, and the rest was water; the top distillate weighed 277g, and the liquid was separated by standing. The lower aqueous phase was directly used in the next batch of extracted liquid for further treatment. The upper organic phase was recorded as component II, and the sample was taken. The GC monitoring composition was: 90.4% 3-ethoxypropionic acid ethyl ester, 7.6% ethanol, and the rest was water.
[0035] Component II was washed with 50g of water twice, and then sampled. The composition of the sample was monitored by GC: 99.5% ethyl 3-ethoxypropionate, 0.01% ethanol, and the rest water. An appropriate amount of 4A molecular sieve was added for drying until the water content was ≤0.03%, and the finished product of ethyl 3-ethoxypropionate was obtained. Example
[0036] 800 g of the produced liquid was placed in a four-necked bottle for fractional distillation. The heating was turned on. When the gas phase temperature was about 74°C, production began, and then there was stable production between 76 and 78°C. When the gas phase temperature rose to 80°C, the liquid temperature in the four-necked bottle was 90°C. The fractional distillation operation was stopped, the temperature was lowered, and the distillate was collected and weighed to about 210 g, recorded as component I. Component I was distilled at a reflux ratio of 2:1, and the first 60% of the fraction was cut out and sampled. The composition monitored by GC was: 43.5% ethanol, 5.6% ethyl acrylate, no 3-ethoxypropionic acid ethyl ester, and water as the balance.
[0037] The residual liquid was put into an intermittent distillation tower, and the heating was turned on for full reflux for 1 hour. The reflux ratio was adjusted to 5:1 to start extraction. When the top temperature reached 85°C, the distillation was stopped and the temperature was lowered. The bottom of the tower was sampled, and the GC monitoring composition was: 0.03% ethanol, no 3-ethoxypropionic acid ethyl ester was detected, and the rest was water; the top distillate weighed 308g, and the liquid was separated by standing. The lower aqueous phase was directly used in the next batch of extracted liquid for further treatment. The upper organic phase was recorded as component II, and the sample was taken. The GC monitoring composition was: 81.3% 3-ethoxypropionic acid ethyl ester, 14.6% ethanol, and the rest was water.
[0038] Component II was washed with 80g of water twice, and then sampled. The composition of 3-ethoxypropionic acid ethyl ester was monitored by GC: 99.6% ethyl 3-ethoxypropionate, 0.01% ethanol, and the rest water. An appropriate amount of super absorbent resin was added to dry until the water content was ≤0.03%, and the finished product of 3-ethoxypropionic acid ethyl ester was obtained.
[0039] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid, characterized in that: The following steps are involved: S1: The collected produced liquid is subjected to simple atmospheric pressure fractionation, the purpose of which is to further concentrate the by-products and obtain the ethanol-rich component I. After fractionation, the mixed solution of ethanol and ethyl acrylate is obtained, which can be directly applied after GC quantification; S2: The residual liquid after fractionation is sent to a distillation tower for atmospheric distillation. After separation of the distillate at the top of the tower, an organic phase rich in ethyl 3-ethoxypropionate can be obtained, which is recorded as component II. The water phase is used in the next batch of produced liquid; the bottom of the tower is water, which can be directly used as a recycled water jacket in the production of α-keto acid; S3: Wash component II twice with an appropriate amount of water, and let it stand for separation to obtain crude ethyl 3-ethoxypropionate containing trace amounts of water; S4: Drying the crude ethyl 3-ethoxypropionate to obtain ethyl 3-ethoxypropionate product with a purity of more than 99.5%.
2. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: The produced liquid in S1 is produced in the production of α-keto acid, and its composition is 3-5% ethyl 3-ethoxypropionate, 25-30% ethanol, 0.5-1% ethyl acrylate, and the rest is water.
3. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: The composition of component I in S1 is: 60-70% ethanol, 2-3% ethyl acrylate, <0.5% ethyl 3-ethoxypropionate, and the rest is water.
4. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: When the gas phase temperature reaches 80°C during fractionation in S1, the extraction is stopped, and the extracted volume is about 28-33% of the total volume.
5. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: During the distillation in S2, when the gas phase temperature reaches 85°C, the distillation is stopped, and the extracted volume is about 30-35% of the total volume.
6. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: The composition of component II in S2 is as follows: the normalized content of ethyl 3-ethoxypropionate is 85-90%, the normalized content of ethanol is 10-15%, and the rest is water.
7. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: The composition of the crude ethyl 3-ethoxypropionate obtained by washing twice in S3 is as follows: the qualitative content of ethyl 3-ethoxypropionate is about 99.5%, the content is about 99%, and the water content is less than 1%.
8. The method for recycling ethyl 3-ethoxypropionate produced as a byproduct in the production of α-keto acid according to claim 1, characterized in that: The selected desiccant is a combination of anhydrous sodium sulfate, anhydrous magnesium sulfate, 4A molecular sieve, 732 resin or highly absorbent resin.