CN115819264A - Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC - Google Patents
Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC Download PDFInfo
- Publication number
- CN115819264A CN115819264A CN202211492304.5A CN202211492304A CN115819264A CN 115819264 A CN115819264 A CN 115819264A CN 202211492304 A CN202211492304 A CN 202211492304A CN 115819264 A CN115819264 A CN 115819264A
- Authority
- CN
- China
- Prior art keywords
- dimethylamine
- liquid
- reaction
- acetic acid
- dmac
- 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.)
- Pending
Links
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 title claims abstract description 222
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 title claims abstract description 198
- 238000010521 absorption reaction Methods 0.000 title claims abstract description 65
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000006243 chemical reaction Methods 0.000 claims abstract description 102
- 239000007788 liquid Substances 0.000 claims abstract description 84
- 238000000926 separation method Methods 0.000 claims abstract description 68
- 239000007791 liquid phase Substances 0.000 claims abstract description 33
- 238000002156 mixing Methods 0.000 claims abstract description 19
- 238000004519 manufacturing process Methods 0.000 claims abstract description 7
- 239000012295 chemical reaction liquid Substances 0.000 claims abstract description 5
- 230000008569 process Effects 0.000 claims description 15
- 239000012808 vapor phase Substances 0.000 claims description 10
- 238000005507 spraying Methods 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 2
- MHABMANUFPZXEB-UHFFFAOYSA-N O-demethyl-aloesaponarin I Natural products O=C1C2=CC=CC(O)=C2C(=O)C2=C1C=C(O)C(C(O)=O)=C2C MHABMANUFPZXEB-UHFFFAOYSA-N 0.000 claims 12
- 239000006096 absorbing agent Substances 0.000 claims 1
- 229940113088 dimethylacetamide Drugs 0.000 claims 1
- 238000001816 cooling Methods 0.000 abstract description 2
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 10
- QHNXEVRKFKHMRL-UHFFFAOYSA-N dimethylazanium;acetate Chemical compound CNC.CC(O)=O QHNXEVRKFKHMRL-UHFFFAOYSA-N 0.000 description 10
- 239000002904 solvent Substances 0.000 description 8
- 239000000498 cooling water Substances 0.000 description 7
- 230000014509 gene expression Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000012071 phase Substances 0.000 description 7
- 230000009471 action Effects 0.000 description 5
- -1 amine acetate salt Chemical class 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- USFZMSVCRYTOJT-UHFFFAOYSA-N Ammonium acetate Chemical class N.CC(O)=O USFZMSVCRYTOJT-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 208000012839 conversion disease Diseases 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- WETWJCDKMRHUPV-UHFFFAOYSA-N acetyl chloride Chemical compound CC(Cl)=O WETWJCDKMRHUPV-UHFFFAOYSA-N 0.000 description 1
- 239000012346 acetyl chloride Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The application provides a method and a system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application thereof, wherein the method comprises the steps of introducing liquid-phase dimethylamine and an acetic acid solution into a mixing device for homogeneous reaction, and cooling to obtain a reaction solution; carrying out gas-liquid separation treatment on the reaction liquid to obtain a separation liquid and a separation tail gas; and dehydrating and purifying the separation liquid to obtain a DMAC product. Different from the prior art, the technical scheme converts the gas-liquid mixed reaction into the liquid-liquid mixed reaction, converts the heterogeneous reaction into the homogeneous reaction, converts the intermittent reaction into the continuous reaction, greatly improves the dimethylamine absorption and mixing efficiency, also improves the dimethylamine reaction yield, and effectively solves the problems of low absorption reaction efficiency and low intermittent production efficiency of the prior art.
Description
Technical Field
The application relates to the technical field of chemical industry, in particular to a method and a system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of the DMAC.
Background
N, N-Dimethylacetamide (DMAC) is an excellent high-boiling point, strong-polarity and non-protonized solvent, has excellent stability, is not easy to decompose and hydrolyze, has low corrosivity and low toxicity, can be completely dissolved with water, ether, ketone, ester and the like, has good dissolving capacity for various resins, is homologous with N, N-Dimethylformamide (DMF) called as solvent king and universal solvent, and has excellent dissolving performance identical to DMF.
DMAC has a large potential market, and almost all the advantages of DMF as a solvent, compared to DMF, while DMAC has a much smaller toxicity than DMF, and DMAC has an absolute advantage over DMF from an environmental point of view, so DMAC will gradually replace DMF in the field of solvent use as a future trend.
The synthesis industrialization technology of DMAC mainly comprises three methods of acetic anhydride method, acetyl chloride method and acetic acid method, the former two methods are basically eliminated at present because of series problems of high production cost, long process route, difficult solvent recovery and the like, and the acetic acid method DMAC is mostly adopted at present, namely acetic acid and dimethylamine are used for reacting to prepare acetic acid amine salt, and then the acetic acid amine salt is reacted and decomposed into DMAC and water under the action of a catalyst.
Regarding DMAC prepared by a reaction of a dimethylamine acetate method, the DMAC prepared by a decomposition reaction of an amine acetate salt is mainly researched by more technologies at present, for example, a method for synthesizing N, N-dimethylacetamide is provided in the patent CN100537521C, in the scheme, amine acetate and dimethylamine are reacted intermittently to synthesize an amine acetate salt, and then a reaction rectifying tower is used for decomposing salt to generate DMAC and realizing separation; in CN112521301A, the amine acetate is prepared by batch reaction, then DMAC is generated by heating the reactor, and a membrane separator is introduced to improve the separation efficiency of the product. These solutions all have certain limitations:
1. salifying at normal pressure is gas-liquid heterogeneous contact mixed reaction, the absorption reaction efficiency is low, and the dimethylamine is excessively introduced into a system, so that the subsequent reaction separation is more complicated;
2. salifying, decomposing and separating device coupling lead to equipment cost height, the operation degree of difficulty is big, and the industrial implementation enlargies the degree of difficulty great.
Disclosure of Invention
In view of the above problems, it is desirable to provide a technical solution for improving the reaction efficiency of acetic acid and dimethylamine and reducing the equipment cost, so as to solve the problems of low absorption reaction efficiency and high operation difficulty in the prior art.
In order to achieve the above object, in a first aspect, the present application provides a method for producing DMAC by continuous absorption of acetic acid and dimethylamine, comprising the steps of:
introducing liquid-phase dimethylamine and an acetic acid solution into a mixing device for homogeneous reaction, and controlling the reaction temperature in the mixing device to obtain a reaction solution;
carrying out gas-liquid separation treatment on the reaction liquid to obtain a separation liquid and a separation tail gas;
and dehydrating and purifying the separation liquid to obtain DMAC.
Compared with the method that gas-phase dimethylamine is used as a synthetic raw material, the reaction efficiency can be greatly improved by using liquid-phase dimethylamine. The liquid phase dimethylamine and the acetic acid solution are both in liquid state, and can be subjected to homogeneous phase contact mixed reaction, so that a catalyst is not needed, the subsequent purification and separation process is simplified, and the reaction conversion rate and the reaction salt forming rate are effectively improved. When dimethylamine reacts with acetic acid solution, a large amount of heat is generated, and liquid-phase dimethylamine is easy to change into a gas phase, thereby influencing the progress of homogeneous reaction. And controlling the reaction temperature in the mixing device to maintain the dimethylamine in a liquid phase, and continuously carrying out homogeneous mixing reaction with the acetic acid. The reaction solution after the reaction contains unreacted dimethylamine completely, and a small amount of dimethylamine carried in the reaction solution is separated from the reaction solution by gas-liquid separation treatment, so that the content of dimethylamine in the reaction solution is reduced, and the subsequent separation and purification are simplified. After gas-liquid separation treatment, separation liquid and separation tail gas are obtained. The separation liquid is mainly dimethylamine acetate, and a DMAC product is obtained through post-treatment processes such as dehydration, purification and the like.
Different from the prior art, the technical scheme optimizes the dimethylamine acetate mixed reaction process, changes the phase state of dimethylamine, converts the gas-liquid mixed reaction into the liquid-liquid mixed reaction, converts the heterogeneous reaction into the homogeneous reaction, and converts the intermittent reaction into the continuous reaction, thereby greatly improving the absorption and mixing efficiency of dimethylamine, improving the reaction yield of dimethylamine and effectively solving the problems of low absorption and reaction efficiency and low intermittent production efficiency of the prior art.
Further, the gas-phase dimethylamine was pressurized to 0.3 to 0.5MPaG to obtain the liquid-phase dimethylamine. Dimethylamine is in the vapor phase at ambient temperature. Dimethylamine was pressurized to 0.3MPaG, so that the dimethylamine changed from a vapor phase to a liquid phase.
Further, the reaction temperature of the reaction liquid in the mixing device is 30-50 ℃. Since dimethylamine generates a large amount of heat upon reaction with the acetic acid solution, the temperature of the reaction solution rises. When the temperature of the reaction solution is too high, dimethylamine tends to become a gas phase, and reacts with acetic acid in a heterogeneous manner. By controlling the reaction temperature within the above range, dimethylamine can be kept in a liquid phase and continuously and homogeneously reacted with acetic acid.
Further, the mixing device is a pipeline mixer, and the liquid-phase dimethylamine and the acetic acid solution are mixed, reacted and cooled in the pipeline mixer. Liquid-phase dimethylamine and acetic acid solution are mixed under pressure in a pipeline mixer. The pipeline mixer has the advantages of short mixing time, low energy consumption, good diffusion effect, medicament saving, simple structure and small occupied area.
Further, spraying the separated tail gas to obtain absorption liquid; and introducing the absorption liquid into the mixing device, and reacting with the liquid-phase dimethylamine and the acetic acid solution together.
Further, acetic acid is adopted to spray the separation tail gas.
And separating a small amount of dimethylamine from the reaction solution after gas-liquid separation. Spraying acetic acid to dimethylamine gas in a normal pressure absorption tower to absorb and purify a small amount of unreacted dimethylamine. Absorbing the dimethylamine gas by acetic acid solution to obtain absorption liquid. The absorption liquid returns to the pipeline mixer through the pipeline under the action of the pump and reacts with the liquid-phase dimethylamine. The whole process forms continuous closed loop, other tail gas absorption solvents are not required to be introduced, the reaction system is simplified, and meanwhile, the problem of tail gas treatment of conventional dimethylamine absorption mixing is solved, so that dimethylamine tail gas and absorption liquid are fully utilized, the reaction efficiency is further improved, and redundant operation is simplified.
Further, a gas-liquid separation tank is adopted to carry out gas-liquid separation on the reaction liquid. The gas-liquid separation tank can be selected from common gas-liquid separation tanks on the market. The size and the model of the gas-liquid separation tank are related to the treatment capacity. The residence time of the liquid in the gas-liquid separation tank can be set to be 5-10min.
In a second aspect, as shown in fig. 1, the present application provides a system for the continuous absorption of acetic acid and dimethylamine to DMAC, comprising:
a line mixer for mixing a liquid phase dimethylamine and an acetic acid solution; the pipeline mixer is provided with a first inlet and a first outlet;
a gas-liquid separation device connected to the first outlet; the gas-liquid separation device is provided with a first gas outlet and a first liquid outlet, and the first liquid outlet is used for discharging separated liquid;
and the absorption tower is connected with the first gas outlet and is used for spraying and absorbing the separated tail gas.
Be different from prior art, above-mentioned technical scheme collects mixed reaction, gas-liquid separation, tail gas absorption as an organic whole, conveys liquid phase dimethylamine to the pipe-line mixer through the pump and mixes, reacts with the acetic acid solution to realize the continuous process of mixing-reaction-cooling in the pipe-line mixer, change heterogeneous phase reaction into homogeneous reaction with the batch reaction, change the continuous reaction into with intermittent type reaction, improved reaction salification efficiency when having improved the reaction conversion rate greatly. After the reaction is finished, the product is conveyed to a gas-liquid separation tank through a pipeline for gas-liquid separation, a small amount of dimethylamine which is carried in the solution and is not completely reacted is separated from the reaction solution, the dimethylamine is reduced to be carried into the next reaction, and the subsequent separation and purification are simplified. By the arrangement, the equipment cost and the operation difficulty are effectively reduced, and series problems of difficulty in equipment manufacture, high cost, high operation difficulty and the like caused by excessively complicated equipment coupling are avoided.
Further, the absorption tower is provided with a second gas outlet and a second liquid outlet, and the second liquid outlet is connected with the first inlet through a pipeline. Dimethylamine is fully absorbed by acetic acid solution in the absorption tower to obtain absorption liquid. The main components in the absorption liquid are acetic acid and dimethylamine, and the absorption liquid is sent back to the pipeline mixer for continuous reaction without introducing other tail gas absorption solvents, thereby simplifying the reaction system and simultaneously solving the problem of tail gas treatment by conventional dimethylamine absorption mixing.
Further, the device also comprises a heat exchange component. The heat exchange part is arranged outside the pipeline mixer. Because dimethylamine and acetic acid reaction can produce a large amount of heats, can absorb the heat that the reaction produced at the external replacement heat spare of pipe mixer, make the temperature of pipe mixer reduce, can control reaction temperature, can retrieve the heat that the reaction produced again, improved resource utilization. The heat exchanging member may be a jacket. The jacket is sleeved outside the pipeline mixer to exchange heat.
In a third aspect, the present application provides the use of a method for the continuous absorption of acetic acid and dimethylamine to prepare DMAC in the field of DMAC preparation.
The above description of the present invention is only an overview of the technical solutions of the present application, and in order to make the technical solutions of the present application more clearly understood by those skilled in the art, the present invention may be further implemented according to the content described in the text and drawings of the present application, and in order to make the above objects, other objects, features, and advantages of the present application more easily understood, the following description is made in conjunction with the detailed description of the present application and the drawings.
Drawings
The drawings are only for purposes of illustrating the principles, implementations, applications, features, and effects of particular embodiments of the present application, as well as others related thereto, and are not to be construed as limiting the application.
In the drawings of the specification:
FIG. 1 is a schematic diagram of a DMAC system with continuous absorption of acetic acid and dimethylamine according to an embodiment of the present application.
Detailed Description
To explain in detail the possible application scenarios, technical principles, and practical embodiments of the present application, and to achieve the objectives and effects thereof, the following detailed description is given with reference to the accompanying drawings. The embodiments described herein are merely for more clearly illustrating the technical solutions of the present application, and therefore, the embodiments are only used as examples, and the scope of the present application is not limited thereby.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or related to other embodiments specifically defined. In principle, in the present application, the technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution as long as there is no technical contradiction or conflict.
Unless defined otherwise, technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the use of relational terms herein is intended to describe specific embodiments only and is not intended to limit the present application.
In the description of the present application, the term "and/or" is a expression for describing a logical relationship between objects, indicating that three relationships may exist, for example, a and/or B, indicating that: there are three cases of A, B, and both A and B. In addition, the character "/" herein generally indicates that the former and latter associated objects are in a logical relationship of "or".
In this application, terms such as "first" and "second" are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
Without further limitation, in this application, the use of "including," "comprising," "having," or other similar expressions in phrases and expressions of "including," "comprising," or "having," is intended to cover a non-exclusive inclusion, and such expressions do not exclude the presence of additional elements in a process, method, or article that includes the recited elements, such that a process, method, or article that includes a list of elements may include not only those elements but also other elements not expressly listed or inherent to such process, method, or article.
As is understood in the examination of the guidelines, the terms "greater than", "less than", "more than" and the like in this application are to be understood as excluding the number; the expressions "above", "below", "within" and the like are understood to include the present numbers. In addition, in the description of the embodiments of the present application, "a plurality" means two or more (including two), and expressions related to "a plurality" similar thereto are also understood, for example, "a plurality of groups", "a plurality of times", and the like, unless specifically defined otherwise.
In the description of the embodiments of the present application, spatially relative expressions such as "central," "longitudinal," "lateral," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used, and the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the specific embodiments or drawings and are only for convenience of describing the specific embodiments of the present application or for the convenience of the reader, and do not indicate or imply that the device or component in question must have a specific position, a specific orientation, or be constructed or operated in a specific orientation and therefore should not be construed as limiting the embodiments of the present application.
Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured," and "disposed" used in the description of the embodiments of the present application are to be construed broadly. For example, the connection can be a fixed connection, a detachable connection, or an integrated arrangement; it can be a mechanical connection, an electrical connection, or a communication connection; they may be directly connected or indirectly connected through an intermediate; which may be communication within two elements or an interaction of two elements. Specific meanings of the above terms in the embodiments of the present application can be understood by those skilled in the art to which the present application pertains in accordance with specific situations.
In order for the reader to more intuitively understand certain embodiments of the present application, the following examples are also provided for the reader's reference.
Example 1:
after dimethylamine was pressurized to 0.4MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 12 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 12mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 30 ℃ for continuous feeding reaction. The reaction pressure in the line mixer was controlled to 0.4MPaG. And (3) after the mixing reaction, conveying the mixture to a normal-pressure gas-liquid separation tank, and performing gas-liquid separation to obtain a separation liquid and a separation tail gas. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused under the environment of 30 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 80 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 95 percent, and the dimethylamine loss in the process is about 1 percent.
Example 2:
after dimethylamine was pressurized to 0.3MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 15 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 12mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 40 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.3MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused under the environment of 30 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 65 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 94 percent, and the dimethylamine loss in the process is about 2 percent.
Example 3:
after dimethylamine was pressurized to 0.5MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 12 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 15mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 30 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.5MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused under the environment of 30 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 86 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 98 percent, and the dimethylamine loss in the process is about 0.3 percent.
Example 4:
after dimethylamine was pressurized to 0.3MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 12 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 20mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 50 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.3MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused under the environment of 30 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 90 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 88 percent, and the dimethylamine loss in the process is about 1.2 percent.
Example 5:
after dimethylamine was pressurized to 0.4MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 20 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 12mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 30 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.4MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused in the environment of 30 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 50 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 95 percent, and the dimethylamine loss in the process is about 2.5 percent.
Example 6:
after dimethylamine was pressurized to 0.3MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 12 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 15mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 40 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.3MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused in the environment of 20 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 83 percent (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 99 percent, and the dimethylamine loss in the process is about 0.2 percent.
Example 7:
after dimethylamine was pressurized to 0.3MPaG at room temperature, the dimethylamine was changed from a vapor phase to a liquid phase. Liquid-phase dimethylamine was continuously pumped into the line mixer by means of a pump at a flow rate of 12 mol/h. The acetic acid solution is introduced into the pipeline mixer at the flow rate of 12mol/h, and the two are continuously mixed and reacted in the pipeline mixer. The pipeline mixer is cooled by an outer jacket filled with cooling water, so that the reaction temperature in the pipeline mixer is kept at 40 ℃ for continuous feeding reaction, the reaction pressure in the pipeline mixer is controlled to be 0.3MPaG, the mixture is conveyed to a normal-pressure gas-liquid separation tank after the reaction, and separation liquid and separation tail gas are obtained after gas-liquid separation. And dehydrating and purifying the separated liquid to obtain a DMAC product. The separated tail gas is connected with an acetic acid absorption tower, and unreacted dimethylamine is absorbed and reused in the environment of 40 ℃ and normal pressure.
In the whole reaction process, the yield of dimethylamine acetate is 78% (calculated by dimethylamine), the absorption efficiency of the acetic acid absorption tower is 85%, and dimethylamine is lost by about 3% in the process.
Finally, it should be noted that, although the above embodiments have been described in the text and drawings of the present application, the scope of the patent protection of the present application is not limited thereby. All technical solutions which are generated by replacing or modifying the equivalent structure or the equivalent flow according to the contents described in the text and the drawings of the present application, and which are directly or indirectly implemented in other related technical fields, are included in the scope of protection of the present application.
Claims (10)
1. A method for preparing DMAC (dimethyl acetamide) by continuously absorbing acetic acid and dimethylamine is characterized by comprising the following steps:
introducing liquid-phase dimethylamine and an acetic acid solution into a mixing device for homogeneous reaction, and controlling the reaction temperature in the mixing device to obtain a reaction solution;
carrying out gas-liquid separation treatment on the reaction liquid to obtain a separation liquid and a separation tail gas;
and dehydrating and purifying the separation liquid to obtain a DMAC product.
2. The process for the continuous absorption of acetic acid and dimethylamine to DMAC of claim 1, wherein dimethylamine in vapor phase is pressurized to 0.3 to 0.5MPaG to obtain dimethylamine in liquid phase.
3. The process for the continuous absorption of acetic acid and dimethylamine of claim 1, DMAC wherein said reaction temperature is from 30 ℃ to 50 ℃.
4. The method for preparing DMAC through continuous absorption of acetic acid and dimethylamine according to claim 1, wherein the separated tail gas is sprayed to obtain an absorption solution; and introducing the absorption liquid into the mixing device, and reacting the absorption liquid with the liquid-phase dimethylamine and the acetic acid solution together.
5. The method for the production of DMAC with continuous absorption of acetic acid and dimethylamine of claim 4, wherein said separated tail gas is sparged with acetic acid.
6. The method for producing DMAC by continuous absorption of acetic acid and dimethylamine according to claim 1, wherein said reaction solution is subjected to vapor-liquid separation using a vapor-liquid separation tank.
7. A system for the continuous absorption of acetic acid and dimethylamine to DMAC, comprising:
a line mixer for mixing the liquid phase dimethylamine and the acetic acid solution; the pipeline mixer is provided with a first inlet and a first outlet;
a gas-liquid separation device connected to the first outlet; the gas-liquid separation device is provided with a first gas outlet and a first liquid outlet, and the first liquid outlet is used for discharging separated liquid;
and the absorption tower is connected with the first gas outlet and is used for spraying and absorbing the separated tail gas.
8. The system for the continuous absorption of acetic acid and dimethylamine to DMAC of claim 7, wherein said absorber comprises a second gas outlet and a second liquid outlet, said second liquid outlet connected to said first inlet by a conduit.
9. The system for the continuous absorption of acetic acid and dimethylamine to DMAC of claim 7, further comprising:
a heat exchange component disposed outside the tube mixer.
10. Use of the method for the preparation of DMAC with continuous absorption of acetic acid and dimethylamine according to claims 1-6 in the field of DMAC preparation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211492304.5A CN115819264A (en) | 2022-11-25 | 2022-11-25 | Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211492304.5A CN115819264A (en) | 2022-11-25 | 2022-11-25 | Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115819264A true CN115819264A (en) | 2023-03-21 |
Family
ID=85531623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211492304.5A Pending CN115819264A (en) | 2022-11-25 | 2022-11-25 | Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115819264A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1865233A (en) * | 2006-06-23 | 2006-11-22 | 江苏工业学院 | Synthesis and rectification method for preparing high purity N, N-dimethyl acetamide |
| CN202576304U (en) * | 2012-04-27 | 2012-12-05 | 河南骏化发展股份有限公司 | Preparation system of dimethyl acetamide |
| CN103524369A (en) * | 2013-10-28 | 2014-01-22 | 连云港阳方催化科技有限公司 | Synthesis method of N, N-dimethylacetamide |
| RU2568120C1 (en) * | 2014-10-02 | 2015-11-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Российский химико-технологический университет имени Д.И. Менделеева (РХТУ им. Д.И. Менделеева) | Method for production and automation of control system for n,n-dimethylacetamide production processes |
| CN105330559A (en) * | 2015-10-14 | 2016-02-17 | 宿迁新亚科技有限公司 | Electronic-grade formamide compound preparation method |
| CN111470563A (en) * | 2020-05-19 | 2020-07-31 | 河北拓康工程技术有限公司 | DMF (dimethyl formamide) or DMAC (dimethylacetamide) waste gas and wastewater series treatment system and method |
| CN113856607A (en) * | 2021-10-21 | 2021-12-31 | 聊城鲁西甲胺化工有限公司 | DMAC (dimethyl acetamide) reaction device for thermal condensation of dimethylamine and acetic acid and application method thereof |
-
2022
- 2022-11-25 CN CN202211492304.5A patent/CN115819264A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1865233A (en) * | 2006-06-23 | 2006-11-22 | 江苏工业学院 | Synthesis and rectification method for preparing high purity N, N-dimethyl acetamide |
| CN202576304U (en) * | 2012-04-27 | 2012-12-05 | 河南骏化发展股份有限公司 | Preparation system of dimethyl acetamide |
| CN103524369A (en) * | 2013-10-28 | 2014-01-22 | 连云港阳方催化科技有限公司 | Synthesis method of N, N-dimethylacetamide |
| RU2568120C1 (en) * | 2014-10-02 | 2015-11-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Российский химико-технологический университет имени Д.И. Менделеева (РХТУ им. Д.И. Менделеева) | Method for production and automation of control system for n,n-dimethylacetamide production processes |
| CN105330559A (en) * | 2015-10-14 | 2016-02-17 | 宿迁新亚科技有限公司 | Electronic-grade formamide compound preparation method |
| CN111470563A (en) * | 2020-05-19 | 2020-07-31 | 河北拓康工程技术有限公司 | DMF (dimethyl formamide) or DMAC (dimethylacetamide) waste gas and wastewater series treatment system and method |
| CN113856607A (en) * | 2021-10-21 | 2021-12-31 | 聊城鲁西甲胺化工有限公司 | DMAC (dimethyl acetamide) reaction device for thermal condensation of dimethylamine and acetic acid and application method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109134231B (en) | Device and process for continuously producing chloroacetic acid by differential circulation | |
| CN110981846B (en) | Method for preparing ethylene carbonate by adopting tubular reactor with static mixer | |
| EP4049748A1 (en) | Gas-liquid bubbling bed reactor, reaction system and method for synthesizing carbonate | |
| CN102442905B (en) | The method of preparing dimethyl adipate by continuous esterification | |
| CN107903165A (en) | A kind of method that m-methyl benzoic acid is continuously prepared using tubular reactor | |
| CN102976945A (en) | Method for synthetizing ethyl chrysanthemumate compound by microreactor | |
| CN103553004B (en) | Method for continuous preparation of sodium azide | |
| CN104876839A (en) | Process for preparing p-toluenesulfonic acid through gas phase SO3 film sulfonation | |
| CN106608865B (en) | Power-economizing method for ethylene carbonate Lipase absobed | |
| CN115819264A (en) | Method and system for preparing DMAC (dimethylacetamide) through continuous absorption of acetic acid and dimethylamine and application of DMAC | |
| CN102502566A (en) | Technology for synthesizing lithium hexafluorophosphate | |
| CN218795951U (en) | Intensive mixed inner member, reaction tube and tubular reactor | |
| CN112939812B (en) | Chlorothalonil production process | |
| CN104387258B (en) | A kind of production of chloroacetic acid method and chlorination reactor | |
| CN1803762A (en) | Triisopropanolamine synthesis apparatus and method | |
| CN113856607A (en) | DMAC (dimethyl acetamide) reaction device for thermal condensation of dimethylamine and acetic acid and application method thereof | |
| CN112694417B (en) | Preparation method and device of 1-cyano-2-propenyl acetate | |
| CN102001938A (en) | Process and production system for synthesizing dimethyl oxalate or diethyl oxalate and coproducing oxalic acid | |
| CN111393402A (en) | Br nsted acid/quaternary ammonium salt composite catalytic CO2Method for preparing cyclic carbonate by cycloaddition with epoxide | |
| CN210885884U (en) | Device for recycling bromine element in industrial production of tetrahydrofurfuryl alcohol ether | |
| CN112694460B (en) | Method and device for continuously synthesizing tetrahydrophthalic anhydride | |
| CN220780358U (en) | Device for producing 2, 6-dichloro fluorobenzene | |
| CN216573024U (en) | Maleic anhydride hydrogenation reaction system | |
| CN110790631B (en) | Device for producing fluorinated alkane through liquid phase method pipelining continuous separation | |
| CN112010776B (en) | Method and device for continuously synthesizing 4-chloro-2-methoxyiminoacetoacetic acid ethyl ester |
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 |