CN112574059A - Separation of N, N-dimethylacetamide-acetic acid mixed system - Google Patents
Separation of N, N-dimethylacetamide-acetic acid mixed system Download PDFInfo
- Publication number
- CN112574059A CN112574059A CN201910935305.4A CN201910935305A CN112574059A CN 112574059 A CN112574059 A CN 112574059A CN 201910935305 A CN201910935305 A CN 201910935305A CN 112574059 A CN112574059 A CN 112574059A
- Authority
- CN
- China
- Prior art keywords
- phase
- dimethylacetamide
- acetic acid
- extraction
- hydrophobic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C231/00—Preparation of carboxylic acid amides
- C07C231/22—Separation; Purification; Stabilisation; Use of additives
- C07C231/24—Separation; Purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/48—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a separation method of an N, N-dimethylacetamide-acetic acid mixed system, which comprises the step of performing biphasic multistage countercurrent extraction on the N, N-dimethylacetamide-acetic acid mixed system by using an extractant group consisting of a hydrophobic phase extractant and a hydrophilic phase extractant. Feeding an N, N-dimethylacetamide-acetic acid mixed system from the middle part of the biphasic multistage countercurrent extraction, and rectifying an extract phase and a raffinate phase of the biphasic multistage extraction respectively to finally obtain N, N-dimethylacetamide and acetic acid products respectively, thereby realizing the separation of the mixed system. In the invention, the diphase multi-stage countercurrent extraction of the selected solvent can effectively break through the restriction of an N, N-dimethylacetamide-acetic acid mixed system, and realize the recovery of N, N-dimethylacetamide and acetic acid.
Description
Technical Field
The invention relates to the field of chemical separation, in particular to a separation method of an N, N-dimethylacetamide-acetic acid mixed system, which particularly adopts an extractant group consisting of a selected hydrophobic phase extractant and a selected hydrophilic phase extractant and a two-phase multistage countercurrent extraction process, breaks through the mixed system and respectively obtains products.
Background
N, N-Dimethylacetamide (DMAC) is a common colorless and transparent non-protonized solvent, can be mutually soluble with various solvents such as water, ethanol, ester, ether and the like, has good solubility for various compounds, and is widely applied to polymer synthesis spinning, the field of medicines and pesticides and the coating industry. In addition, the method is also applicable to catalysis, extraction and electrolysis.
The synthesis process of N, N-dimethyl acetamide is mainly amidation reaction of acetic acid and its derivative as material and dimethylamine to produce N, N-dimethyl acetamide. After the reaction has ended, a certain amount of acetic acid may be present in addition to the product. Meanwhile, N, N-dimethylacetamide is also decomposed into dimethylamine and acetic acid under long-term high-temperature operation, and the acetic acid generated by decomposition accelerates the decomposition of N, N-dimethylacetamide, so that a vicious cycle is formed. It is necessary to separate N, N-dimethylacetamide and acetic acid to obtain N, N-dimethylacetamide by combining the production process of N, N-dimethylacetamide and the waste water recovery process thereof.
However, in practice, although there is a large difference in boiling points between N, N-dimethylacetamide and acetic acid, one boiling point at atmospheric pressure is 166 ℃ and the other is 119 ℃. However, due to the hydrogen bonding effect, in the presence of acetic acid, N-dimethylacetamide acts as a base and is strongly attracted, which is finally shown in that they can form the highest mixture in a certain proportion, a newly composed mixture with a boiling point of 171 ℃ higher than the boiling points of both, wherein N, N-dimethylacetamide accounts for 79% and acetic acid for 21%. Since both of them form the highest mixture, separation is difficult by conventional rectification, and the formed mixture remains in the column during rectification.
For the separation of the N, N-dimethylacetamide-acetic acid mixed system, there are few reports of research, and the method mainly focuses on using alkali to neutralize the acid and then continuously recovering the N, N-dimethylacetamide by rectification, as in patent document CN 101462977B. Although the method can recover and obtain the N, N-dimethylacetamide, the method can cause waste of acetic acid resources. Meanwhile, there is a patent document such as CN 1665574a reporting a method for purifying N, N-dimethylacetamide in an aqueous solution containing acetic acid contaminants by using two fractionation columns connected in series. The method has small operation flexibility, and the separation effect is completely dependent on the quality of the operation.
Disclosure of Invention
In order to solve the above problems and improve the comprehensive utilization of resources, it is necessary to develop a separation method for an N, N-dimethylacetamide-acetic acid mixed system to obtain N, N-dimethylacetamide and acetic acid products respectively.
The invention provides a separation method of an N, N-dimethylacetamide-acetic acid mixed system, in particular to a biphase multistage countercurrent extraction process taking an extractant group consisting of a selected hydrophobic phase extractant and a hydrophilic phase extractant as a core, and a rectification process, so that qualified N, N-dimethylacetamide and acetic acid products can be obtained respectively. The process method can effectively break the restriction of a mixing system, respectively obtain qualified products, and has the advantages of simple process and high operation flexibility.
The second aspect of the invention provides the use of the above process for the separation of mixed systems, especially for the separation of azeotropic systems.
According to the first aspect of the present invention, the method for separating the N, N-dimethylacetamide-acetic acid mixed system uses an extraction agent group consisting of a hydrophobic phase extraction agent and a hydrophilic phase extraction agent to extract the N, N-dimethylacetamide-acetic acid mixed system.
According to some embodiments of the present invention, the extractant group comprises a hydrophobic phase extractant and a hydrophilic phase extractant, and the two groups of solvents used in the biphasic extraction must be separated, so that the extractants are selected in consideration of mutual solubility between the N, N-dimethylacetamide and acetic acid in addition to the extraction performance, and the poorer the mutual solubility, the smaller the loss of the extractants in the extraction process is, and the extraction process is facilitated.
According to some embodiments of the invention, the hydrophobic phase extractant comprises one or more selected from the group consisting of chloroform, eugenol, and aniline.
According to some embodiments of the invention, the hydrophilic phase extractant comprises water.
According to some preferred embodiments of the present invention, the chloroform, eugenol and aniline are insoluble or slightly soluble in water, and the molecular structures of the chloroform, eugenol and aniline contain relatively active hydrogen, which can form hydrogen bonding with N, N-dimethylacetamide, thereby having relatively strong extraction capability on N, N-dimethylacetamide. The polarity of acetic acid will be stronger for N, N-dimethylacetamide and thus it will bind more easily to water and concentrate in the aqueous phase during extraction. Finally, the final separation is achieved by the difference of the partition coefficients of the N, N-dimethylacetamide and the acetic acid in the two phases.
According to some embodiments of the invention, the mass ratio of N, N-dimethylacetamide to acetic acid in the N, N-dimethylacetamide-acetic acid mixed system is (20-90): (10-80).
According to some embodiments of the present invention, the mass ratio of N, N-dimethylacetamide to acetic acid in the N, N-dimethylacetamide-acetic acid mixed system is 79:21, 50:50, 30:70, 20:80, 60:40, 85:15, but not limited to the above ratio. The separation of N, N-dimethylacetamide-acetic acid mixtures in any ratio can be carried out by the present invention.
According to some embodiments of the invention, the mass ratio of the hydrophobic phase extractant to the hydrophilic phase extractant is between 0.2 and 5, preferably between 0.5 and 2, more preferably between 0.8 and 1.25. The ratio of the hydrophobic phase to the hydrophilic phase affects the extraction efficiency, and when the hydrophobic extractant is used in a small amount, the extraction of N, N-dimethylacetamide is reduced, and finally, a part of N, N-dimethylacetamide in the aqueous phase can be remained. Similarly, when the amount of hydrophilic extractant used is small, extraction of acetic acid is impaired, and eventually a portion of acetic acid may remain in the organic phase. The applicant has found through a large number of experimental studies that the above-mentioned ratio of hydrophobic and hydrophilic phases is suitable.
According to some embodiments of the invention, the mass flow rate of the N, N-dimethylacetamide-acetic acid mixed system is 0.01 to 0.50 times the total mass flow rate of the hydrophobic phase extractant and the hydrophilic phase extractant. The mass flow rate of the N, N-dimethylacetamide-acetic acid mixed system is not too high compared with the total mass flow rate of the extracting agent, if the mass flow rate is too high, the ratio means that the amount of the extracting agent is less, the extraction of the N, N-dimethylacetamide and acetic acid is not favorable, and finally the goal of obtaining qualified N, N-dimethylacetamide and acetic acid products is not achieved.
According to some embodiments of the invention, the extraction is a biphasic multistage countercurrent extraction.
According to some embodiments of the invention, the number of stages of the biphasic multistage countercurrent extraction is N stages, N being a positive integer greater than or equal to 3.
According to some embodiments of the present invention, the total number of stages of the biphasic multistage countercurrent extraction is 6-16, and too low number of stages can affect the extraction effect of N, N-dimethylacetamide and acetic acid, resulting in incomplete extraction and residue. And the stage number is too high, so that the complete separation of the N, N-dimethylacetamide and the acetic acid can be realized, but the effect is not greatly improved, and the waste of equipment is caused. Thus, a suitable number of extraction stages is required.
According to some embodiments of the invention, the N, N-dimethylacetamide-acetic acid mixed system is introduced from the middle of a biphasic multistage countercurrent extraction, and the hydrophobic phase extractant and the hydrophilic phase extractant are introduced from both ends of the multistage countercurrent extraction, respectively.
According to some embodiments of the invention, the hydrophobic phase extractant is introduced from the first stage, the hydrophilic phase extractant is introduced from the nth stage, and the N, N-dimethylacetamide-acetic acid mixed system is introduced from any one of the third to N-2 stages. The corresponding feed position is required to be determined according to the total extraction stage number and the ratio of the N, N-dimethylacetamide to the acetic acid mixture.
According to some embodiments of the invention, the extraction temperature of the biphasic multistage countercurrent extraction is between 5 ℃ and 45 ℃; preferably from 15 ℃ to 35 ℃; more preferably from 20 ℃ to 30 ℃. Within the above temperature range, the temperature range is a temperature range in which the extraction effect is good in the present invention. Higher temperatures can increase mass transfer of N, N-dimethylacetamide and acetic acid in the two phases, decreasing the time required for equilibration, while too high temperatures can decrease the extraction efficiency of both phases. Therefore, the temperature needs to be controlled under certain conditions during extraction.
According to some embodiments of the invention, the biphasic multistage countercurrent extraction is carried out in a mixer-settler or a centrifugal extractor. The mixer-settler is a conventional extraction equipment, and usually comprises two parts, namely a mixing chamber and a clarifying chamber, wherein a stirring paddle with large blades is arranged in the mixing chamber to ensure that the two phases are fully mixed and contacted. The centrifugal extractor is a new type of high-efficiency extraction and separation equipment, which is mainly composed of a motor, a rotary drum, a mixer, a shell, a frame and other parts. The two phases enter between the shell and the rotary drum from the two feed inlets to be mixed through a mixer, then enter a centrifugal area, and are separated through the difference of density, and finally, a clear extract phase and a clear raffinate phase are obtained.
According to some embodiments of the present invention, the method for separating the N, N-dimethylacetamide-acetic acid mixed system further comprises rectifying the extracted extract and raffinate.
According to some embodiments of the invention, the extract is subjected to rectification to obtain N, N-dimethylacetamide and the raffinate is subjected to rectification to obtain acetic acid.
According to some embodiments of the invention, the operating pressure of the raffinate rectification is from 0.25atm to 1atm, preferably from 0.5 to 1atm, more preferably from 0.75 to 1 atm; the reflux ratio of the raffinate rectification is 0.5-10, preferably 1-5, and more preferably 2-5; the temperature of the bottom of the raffinate rectification column is controlled at 79-116 ℃.
According to some embodiments of the invention, the operating pressure of the rectification of the extract is from 0.25atm to 1atm, preferably from 0.25atm to 0.75atm, more preferably from 0.25atm to 0.5 atm; the reflux ratio of the extract liquid rectification is 0.2-10, preferably 0.2-5; more preferably 0.5 to 2; the temperature of the tower bottom or the tower top of the extraction liquid rectification is controlled to be 120-166 ℃.
In some preferred embodiments of the invention, the highest product purity and recovery can be obtained with the highest reflux ratio, however, the disadvantage of high reflux ratio is that the energy consumption is very high, and therefore moderate reflux ratios are used in generally optimal conditions.
The above preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention without departing from the common general knowledge in the art.
The positive progress effects of the invention are as follows: the invention provides a separation and recovery method for a mixed system of N, N-dimethylacetamide and acetic acid, which comprises the steps of carrying out multi-stage countercurrent extraction on the mixed system through a selected extraction agent group, then destroying the mixed system in a rectification mode, and respectively recovering and obtaining the N, N-dimethylacetamide and the acetic acid. The invention has simple process and large operation flexibility, and the recovered product meets the required requirements, wherein the purity of the N, N-dimethylacetamide is more than 99 percent, and the purity of the acetic acid is more than 92 percent.
Drawings
FIG. 1 is a flow chart of a separation process of an N, N-dimethylacetamide-acetic acid mixed system, wherein the first step is biphase multistage countercurrent extraction, the second step is a raffinate phase rectification recovery tower, and the third step is an extract phase rectification recovery tower. Numeral 1 indicates a mixture of N, N-dimethylacetamide and acetic acid, i.e., an object to be separated, 2 is a hydrophobic phase extractant, 3 is a hydrophilic phase extractant, 4 is an raffinate phase after multistage countercurrent extraction, 5 is an extract phase after multistage countercurrent extraction, 6 is a top product of a raffinate phase rectifying tower, 7 is a bottom product of the raffinate phase rectifying tower, 8 is a top product of the extract phase rectifying tower, and 9 is a bottom product of the extract phase rectifying tower.
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.
In the invention, the purity of the N, N-dimethylacetamide in all the examples is detected by HPLC, and the purity of the acetic acid is determined by an acid-base neutralization titration method.
Example 1
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared by taking chloroform as a hydrophobic phase and water as a hydrophilic phase in a mass ratio of 50:50, and performing two-phase multi-stage countercurrent extraction, wherein the total extraction stages are 12 stages, and the mixture enters from the 6 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 92.6 percent through detection, and the recovery rate is 91.3 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.25atm, the reflux ratio is 0.2, the temperature of the tower kettle is controlled to be 120 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.0% through detection, and the recovery rate is 95.2% through conversion.
Example 2
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 30:70, eugenol is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 4 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 0.5. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 1, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 93.2% through detection, and the recovery rate is 91.9% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature at the top of the tower is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the top of the tower, the purity is 99.1 percent through detection, and the recovery rate is 95.5 percent through conversion.
Example 3
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 20:80, aniline is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 3 rd stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 0.2. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 2, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 93.9 percent through detection, and the recovery rate is 92.4 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.75atm, the reflux ratio is 1, the temperature at the top of the tower is controlled to be 156 ℃, and finally the N, N-dimethylacetamide product is obtained at the top of the tower, the purity is 99.2 percent through detection, and the recovery rate is 95.6 percent through conversion.
Example 4
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 3, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 94.5% through detection, and the recovery rate is 93.0% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 1atm, the reflux ratio is 1.5, the temperature of a tower kettle is controlled to be 166 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.8% through conversion.
Example 5
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 60:40, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 7 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 0.8. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 4, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 95.2 percent through detection, and the recovery rate is 94.0 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 2, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.3% through detection, and the recovery rate is 96.3% through conversion.
Example 6
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 85:15, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 9 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 2. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.7% through detection, and the recovery rate is 94.5% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.5% through detection, and the recovery rate is 96.7% through conversion.
Example 7
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage number is 6, and the mixture enters from the 4 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.01 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 6, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 96.0 percent through detection, and the recovery rate is 90.8 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 10, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.7% through detection, and the recovery rate is 95.1% through conversion.
Example 8
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 8 stages, and the mixture enters from the 6 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.05 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 5 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 8, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 96.2 percent through detection, and the recovery rate is 92.2 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.0% through conversion.
Example 9
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage is 10 stages, and the mixture enters from the 7 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.1 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 15 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 10, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 96.5 percent through detection, and the recovery rate is 93.4 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.3% through detection, and the recovery rate is 95.4% through conversion.
Example 10
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 20 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.8 percent through detection, and the recovery rate is 94.6 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.8% through conversion.
Example 11
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage is 14 stages, and the mixture enters from the 10 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.3 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 30 ℃ to obtain an extract phase and a raffinate phase respectively. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 96.0% through detection, and the recovery rate is 95.2% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 96.2% through conversion.
Example 12
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage is 16 stages, and the mixture enters from the 13 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.5 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 35 ℃ to obtain an extract phase and a raffinate phase respectively. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 95.7 percent through detection, and the recovery rate is 95.4 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 96.8% through conversion.
Example 13
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 40 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.5% through detection, and the recovery rate is 94.3% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.6% through conversion.
Example 14
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 45 ℃ to obtain an extract phase and a raffinate phase respectively. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.4% through detection, and the recovery rate is 94.0% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.1% through detection, and the recovery rate is 95.4% through conversion.
Example 15
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.25atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 79 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 93.6 percent through detection, and the recovery rate is 92.9 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.7% through conversion.
Example 16
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.75atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 108 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 96.2% through detection, and the recovery rate is 94.8% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.1% through detection, and the recovery rate is 96.1% through conversion.
Example 17
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 1atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 116 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 96.7% through detection, and the recovery rate is 95.5% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.3% through detection, and the recovery rate is 95.6% through conversion.
Example 18
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.9% through detection, and the recovery rate is 94.5% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 96.1% through conversion.
Example 19
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 0.8. The extraction is carried out at 20 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 95.9 percent through detection, and the recovery rate is 95.1 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.2% through detection, and the recovery rate is 95.4% through conversion.
Example 20
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 0.5. The extraction is carried out at 20 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 96.1% through detection, and the recovery rate is 95.4% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.1% through detection, and the recovery rate is 95.1% through conversion.
Example 21
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stages are 12 stages, and the mixture enters from the 8 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow of the treated mixture was 0.2 times the mass flow of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 2. The extraction is carried out at 20 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 5, the temperature of the tower kettle is controlled to be 96 ℃, and finally an acetic acid product is obtained at the tower kettle, the purity is 95.2% through detection, and the recovery rate is 92.7% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 0.5, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.4% through detection, and the recovery rate is 96.6% through conversion.
Example 22
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage is 5 stages, and the mixture enters from the 4 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.01 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And the raffinate phase enters a raffinate phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 6, the temperature of the tower kettle is controlled to be 96 ℃, finally, an acetic acid product is obtained at the tower kettle, the purity is 96.2 percent through detection, and the recovery rate is 85.6 percent through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 10, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 98.7% through detection, and the recovery rate is 96.5% through conversion.
Example 23
A batch of mixture of N, N-dimethylacetamide and acetic acid is prepared, the mass ratio is 79:21, chloroform is used as a hydrophobic phase, water is used as a hydrophilic phase, two-phase multi-stage countercurrent extraction is carried out, the total extraction stage is 16 stages, and the mixture enters from the 11 th stage position counted from a feed inlet of the hydrophobic phase. The mass flow rate of the treated mixture was 0.2 times the mass flow rate of the total extractant (comprising hydrophobic and hydrophilic phases) with a mass ratio of hydrophobic to hydrophilic phase of 1.25. The extraction is carried out at 25 ℃, and an extract phase and a raffinate phase are respectively obtained. And (3) allowing the raffinate to enter a raffinate rectification tower, controlling the operating pressure to be 1atm, the reflux ratio to be 10 and the temperature of the tower kettle to be 96 ℃, and finally obtaining an acetic acid product at the tower kettle, wherein the purity is 97.0% through detection and the recovery rate is 96.2% through conversion. The extract phase enters an extract phase rectifying tower, the operating pressure is 0.5atm, the reflux ratio is 10, the temperature of the tower kettle is controlled to be 141 ℃, and finally, an N, N-dimethylacetamide product is obtained at the tower kettle, the purity is 99.7% through detection, and the recovery rate is 97.2% through conversion.
It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not set any limit to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.
Claims (10)
1. A separation method of an N, N-dimethylacetamide-acetic acid mixed system comprises the step of extracting the N, N-dimethylacetamide-acetic acid mixed system by using an extracting agent group consisting of a hydrophobic phase extracting agent and a hydrophilic phase extracting agent.
2. The method of claim 1, wherein the hydrophobic phase extractant comprises one or more selected from the group consisting of chloroform, eugenol, and aniline, and the hydrophilic phase extractant comprises water.
3. The method according to claim 1 or 2, wherein the mass ratio of N, N-dimethylacetamide to acetic acid in the N, N-dimethylacetamide-acetic acid mixed system is (20-90) to (10-80); and/or the presence of a gas in the gas,
the mass ratio of the hydrophobic phase extractant to the hydrophilic phase extractant is 0.2-5, preferably 0.5-2, and more preferably 0.8-1.25; and/or the presence of a gas in the gas,
the mass flow of the N, N-dimethylacetamide-acetic acid mixed system is 0.01-0.50 times of the total mass flow of the hydrophobic phase extractant and the hydrophilic phase extractant.
4. The process according to any one of claims 1 to 3, wherein the extraction is a biphasic multistage countercurrent extraction, preferably the biphasic multistage countercurrent extraction has a number of stages N, N being a positive integer greater than or equal to 3, preferably a positive integer from 6 to 16, more preferably the hydrophobic phase extractant is introduced from the first stage, the hydrophilic phase extractant from the Nth stage, and the N, N-dimethylacetamide-acetic acid mixed system is introduced from any one of the third to the Nth-2 stages.
5. The method according to any one of claims 1 to 4, wherein the temperature of the extraction is 5 ℃ to 45 ℃; preferably from 15 ℃ to 35 ℃; more preferably from 20 ℃ to 30 ℃.
6. The process according to any one of claims 1 to 5, characterized in that the biphasic multistage countercurrent extraction is carried out in a mixer-settler or a centrifugal extractor.
7. The method according to any one of claims 1 to 6, further comprising rectifying the extracted extract and raffinate, preferably the extract is rectified to obtain N, N-dimethylacetamide and the raffinate is rectified to obtain acetic acid.
8. The process according to any one of claims 1 to 7, characterized in that the operating pressure of the raffinate rectification is between 0.25atm and 1atm, preferably between 0.5 and 1atm, more preferably between 0.75 and 1 atm; the reflux ratio of the raffinate rectification is 0.5-10, preferably 1-5, and more preferably 2-5; the temperature of the bottom of the raffinate rectification column is controlled at 79-116 ℃.
9. The process according to any one of claims 1 to 8, characterized in that the operating pressure of the rectification of the extract is from 0.25atm to 1atm, preferably from 0.25atm to 0.75atm, more preferably from 0.25atm to 0.5 atm; the reflux ratio of the extract liquid rectification is 0.2-10, preferably 0.2-5; more preferably 0.5 to 2; the temperature of the tower bottom or the tower top of the extraction liquid rectification is controlled to be 120-166 ℃.
10. Use of the process according to any one of claims 1 to 9 for the separation of N, N-dimethylacetamide-acetic acid mixed systems, in particular for the separation of N, N-dimethylacetamide-acetic acid azeotropic systems.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910935305.4A CN112574059B (en) | 2019-09-29 | 2019-09-29 | Separation of N, N-dimethylacetamide-acetic acid mixed system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910935305.4A CN112574059B (en) | 2019-09-29 | 2019-09-29 | Separation of N, N-dimethylacetamide-acetic acid mixed system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112574059A true CN112574059A (en) | 2021-03-30 |
| CN112574059B CN112574059B (en) | 2022-10-11 |
Family
ID=75111214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910935305.4A Active CN112574059B (en) | 2019-09-29 | 2019-09-29 | Separation of N, N-dimethylacetamide-acetic acid mixed system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112574059B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112513007A (en) * | 2020-10-23 | 2021-03-16 | 安徽金禾实业股份有限公司 | DMF (dimethyl formamide) recovery method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB814271A (en) * | 1956-08-10 | 1959-06-03 | Union Carbide Corp | Method for the purification of n,n-dimethylacetamide |
| GB1165278A (en) * | 1966-12-15 | 1969-09-24 | Du Pont | Separation of Dimethylacetamide from Mixtures by Distillation |
| US3959371A (en) * | 1974-10-08 | 1976-05-25 | Custom Organics, Inc. | Process for the purification of N,N-dimethylacetamide |
| US5578201A (en) * | 1993-07-30 | 1996-11-26 | E. I. Du Pont De Nemours And Company | Apparatus for mixing liquids used in countercurrent multiphase liquid separation |
| CN101838215A (en) * | 2010-05-25 | 2010-09-22 | 刘伟斌 | Process for separating acetic acid from DMAC azeotrope |
| CN104592050A (en) * | 2014-12-25 | 2015-05-06 | 天津大学 | Method for recovering N, N-dimethylacetamide solvent used in production of spandex |
-
2019
- 2019-09-29 CN CN201910935305.4A patent/CN112574059B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB814271A (en) * | 1956-08-10 | 1959-06-03 | Union Carbide Corp | Method for the purification of n,n-dimethylacetamide |
| GB1165278A (en) * | 1966-12-15 | 1969-09-24 | Du Pont | Separation of Dimethylacetamide from Mixtures by Distillation |
| US3959371A (en) * | 1974-10-08 | 1976-05-25 | Custom Organics, Inc. | Process for the purification of N,N-dimethylacetamide |
| US5578201A (en) * | 1993-07-30 | 1996-11-26 | E. I. Du Pont De Nemours And Company | Apparatus for mixing liquids used in countercurrent multiphase liquid separation |
| CN101838215A (en) * | 2010-05-25 | 2010-09-22 | 刘伟斌 | Process for separating acetic acid from DMAC azeotrope |
| CN104592050A (en) * | 2014-12-25 | 2015-05-06 | 天津大学 | Method for recovering N, N-dimethylacetamide solvent used in production of spandex |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112513007A (en) * | 2020-10-23 | 2021-03-16 | 安徽金禾实业股份有限公司 | DMF (dimethyl formamide) recovery method |
| CN112513007B (en) * | 2020-10-23 | 2022-01-21 | 安徽金禾实业股份有限公司 | DMF (dimethyl formamide) recovery method |
| WO2022082752A1 (en) * | 2020-10-23 | 2022-04-28 | 安徽金禾实业股份有限公司 | Dmf recycling method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112574059B (en) | 2022-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11667597B2 (en) | Method for linkage recovery of organic acid in aqueous organic acid solution | |
| CN102060831B (en) | Method for separating mixed tocopherols from plant oil deodorizer condensates | |
| KR20140030255A (en) | Method for recovering acetic acid | |
| CN106831471A (en) | A kind of method for removing a small amount of acid or glacial acetic acid and refining DMF | |
| US8680329B2 (en) | Process for preparation of α-ketoglutaric acid | |
| CN112574059B (en) | Separation of N, N-dimethylacetamide-acetic acid mixed system | |
| CN112574060B (en) | Recovery method of N, N-dimethylacetamide | |
| CN109761872B (en) | NMP centrifugal extraction purification device and purification method | |
| CN111777495B (en) | Method for separating solid mixture of sodium phenolate and sodium hydroxide and extracting, separating and recovering phenol from toluene | |
| CN114920642B (en) | Separation process for obtaining high-purity fatty acid monoglyceride and fatty acid diglyceride | |
| CN108721942B (en) | Continuous countercurrent reaction process of liquid phase mixture and application | |
| CN102731299B (en) | Liquid-liquid extraction separation method of methyl propionate-methanol-water azeotropic system | |
| CN105315149B (en) | A kind of method for preparing sodium citrate | |
| CN115814452A (en) | Methyl methacrylate separation and purification method and device | |
| CN111777494B (en) | Leaching and separating method for solid mixture of sodium phenolate and sodium hydroxide | |
| CN111252746B (en) | Continuous sodium azide water phase safety production device and process | |
| CN113980070A (en) | Method for purifying hydrophilic mannosylerythritol lipids | |
| CN105130779B (en) | A kind of device and method for separating butanone, ethyl acetate and isopropanol water solution | |
| CN101804331B (en) | Dendritic polyamine adsorptive resin and preparation method thereof | |
| CN114436359B (en) | Method for extracting and recovering N, N-dimethylacetamide in wastewater | |
| CN116854633B (en) | Application of silicon carbide micro-channel reactor and preparation method of 2-chloro-3-aminopyridine | |
| CN101265174A (en) | Method for extracting hydroxyacetic acid from water solution mixture containing hydroxyacetic acid | |
| CN111848385B (en) | Extraction method of itaconic acid in fermentation process itaconic acid mother liquor | |
| CN211636444U (en) | Water washing continuous production device for thiodicarb | |
| CN116924918B (en) | Preparation method of 3-amino-1-adamantanol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |