CN214088353U

CN214088353U - Synthesis device of DMAC (dimethylacetamide)

Info

Publication number: CN214088353U
Application number: CN202023094565.0U
Authority: CN
Inventors: 姜维强; 张正颂; 侯方方; 杨志健; 赵金刚; 郑学连
Original assignee: Anhui Jinhe Industrial Co Ltd
Current assignee: Anhui Jinhe Industrial Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-08-31
Anticipated expiration: 2030-12-21

Abstract

The utility model provides a synthesizer of DMAC, includes neutralization reactor, heating equipment, membrane separator, condensing equipment, vacuum apparatus and refining equipment, and neutralization reactor outlet end links to each other with the heating equipment entry end, and the heating equipment exit end links to each other with the membrane separator entry end, and the first exit end of membrane separator links to each other with the condensing equipment entry end, and the second exit end of membrane separator links to each other with the refining equipment entry end, and the condensing equipment links to each other with vacuum apparatus. The device has the advantages of simple structure, reasonable design, and high efficiency and convenience in use. The membrane dehydration process is applied to the reaction of dimethylamine and acetic acid to prepare DMAC, so that the reaction conversion rate and selectivity are obviously improved, and the product yield of DMAC is improved. The dehydration reaction temperature is lower than that of the traditional process, the energy consumption in the production process is reduced, the process is continuous, the operation is simple and convenient, and the production cost is reduced.

Description

Synthesis device of DMAC (dimethylacetamide)

Technical Field

The utility model relates to a synthetic device of DMAC.

Background

N, N-dimethylacetamide is abbreviated as DMAC, and the boiling point is 165 ℃ at normal pressure. The DMAC can be mixed and dissolved with water, alcohol, ether, ester, ketone, aromatic compounds and the like, has good solubility on various organic and inorganic substances and high molecular polymers, is called as a universal solvent, is widely applied to petrochemical industry and organic synthesis industry, and is an important chemical raw material and an organic solvent.

The DMAC synthesis method mainly includes an acetic anhydride method, an acetyl chloride method, an acetic acid method, a trimethylamine carbonylation method, a methyl acetate method, and the like. Wherein the acetic anhydride method, the acetyl chloride method and the acetic acid method are all realized by industrialized production. At present, the acetic acid method is the most mature and domestic main process method for producing DMAC. There are many reports on the synthesis of DMAC by acetic acid method in domestic and foreign patents. Japanese patent JP53082716 proposes the preparation of DMAC by the reaction of dimethylamine and acetic acid catalyzed by molybdenum oxide, but the DMAC yield is low. In patent CN1298382A of Mitsubishi yang corporation, normal pressure neutralization is reported, and then DMAC is synthesized under the conditions of 150-250 ℃ and 1-3 MPa, and the main defects are that high pressure reaction is required, the requirement on equipment is high, and the equipment investment is large. Korean three-star patent KR109990044579 also reports that salt is neutralized to 50-160 ℃ first, salt is continuously reacted to generate DMAC under the catalysis of aluminum salt at 130-180 ℃, but aluminum salt is unstable in the reaction, so that the reaction yield is unstable. The U.S. DuPont introduces DMAC preparation under the conditions of 3.5-4.9 MPa and 180-235 ℃ in the patent US3300531, and the technical process route is complex, high-temperature and high-pressure reaction is required, and the requirement on equipment is high.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a DMAC's synthesizer is provided, the device simple structure, reasonable in design uses high-efficiently convenient. The method has the advantages of improving the reaction conversion rate and selectivity, improving the yield of the DMAC product, reducing the energy consumption in the production process, realizing the continuity of the technical process, along with simple and convenient operation and reduction of the production cost.

For solving the technical problem, the utility model provides a DMAC's synthesizer, including neutralization reactor, firing equipment, membrane separator, condensing equipment, vacuum apparatus and refined equipment, neutralization reactor exit end links to each other with the firing equipment entry end, and the firing equipment exit end links to each other with the membrane separator entry end, and the first exit end of membrane separator links to each other with the condensing equipment entry end, and membrane separator second exit end links to each other with the refined equipment entry end, and the condensing equipment links to each other with vacuum apparatus.

The refining equipment is two rectifying towers connected in series.

The rectifying tower is a packed tower or a plate tower.

The neutralization reactor is a reaction kettle or a tubular reactor.

For the sake of simplicity, the DMAC synthesizer of the present invention is simply referred to as the present device below.

The method for synthesizing DMAC by using the device comprises the following steps:

(1) adding acetic acid, dimethylamine and a catalyst into a neutralization reactor to carry out neutralization reaction, and obtaining a neutralization reaction mixture at the outlet end of the neutralization reactor;

(2) heating the neutralized reaction mixture by a heater, then feeding the heated neutralized reaction mixture into a membrane separator, obtaining a dehydration product at the outlet end of the membrane separator, and condensing and collecting water dehydrated by the membrane separator under vacuum;

(3) and carrying out DMAC refining treatment on the dehydration product to obtain a high-purity DMAC product.

In the step (1), the neutralization reaction is carried out at a temperature of 40-80 ℃ for 10-120 min, the molar ratio of acetic acid to dimethylamine is 1: 1-5: 1, the mass fraction of the catalyst is 0.1-5%, and the catalyst is Lewis acid.

In the step (1), the pH value of the outlet of the neutralization reactor is 5-7.

In the step (2), the temperature of the dehydration reaction is 100-180 ℃, and the retention time of the dehydration reaction is 10-60 min.

In the step (2), the membrane separator has a water permeability of 95-99% and a permeability of 0-5% for acetic acid and dimethylamine.

In the step (2), the flow ratio of the membrane area of the membrane separator to the neutralized mixture is 0.1-1 m²/(m³H) and the vacuum degree is-0.09 to-0.03 MPa.

The device has the advantages that: the device has the advantages of simple structure, reasonable design, and high efficiency and convenience in use. The membrane dehydration process is applied to the reaction of dimethylamine and acetic acid to prepare DMAC, so that the reaction conversion rate and selectivity are obviously improved, and the product yield of DMAC is improved. The dehydration reaction temperature is lower than that of the traditional process, the energy consumption in the production process is reduced, the process is continuous, the operation is simple and convenient, and the production cost is reduced.

Drawings

Fig. 1 is a schematic diagram showing the connection relationship of the components of the device.

Detailed Description

The first embodiment is as follows:

referring to fig. 1, a DMAC synthesizing apparatus includes a neutralization reactor 1, a heating device 2, a membrane separator 3, a condensing device 5, a vacuum device 6 and a refining device 4, the neutralization reactor 1 is a reaction kettle, an outlet end of the neutralization reactor 1 is connected with an inlet end of the heating device 2, an outlet end of the heating device 2 is connected with an inlet end of the membrane separator 3, a first outlet end of the membrane separator 3 is connected with an inlet end of the condensing device 5, a second outlet end of the membrane separator 3 is connected with an inlet end of the refining device 4, and the condensing device 5 is connected with the vacuum device 6. The refining equipment 4 is two rectifying towers connected in series, and the rectifying towers are packed towers.

Example two:

referring to fig. 1, a DMAC synthesizing apparatus includes a neutralization reactor 1, a heating device 2, a membrane separator 3, a condensing device 5, a vacuum device 6 and a refining device 4, where the neutralization reactor 1 is a tubular reactor, an outlet end of the neutralization reactor 1 is connected to an inlet end of the heating device 2, an outlet end of the heating device 2 is connected to an inlet end of the membrane separator 3, a first outlet end of the membrane separator 3 is connected to an inlet end of the condensing device 5, a second outlet end of the membrane separator 3 is connected to an inlet end of the refining device 4, and the condensing device 5 is connected to the vacuum device 6. The refining equipment 4 is two rectifying towers connected in series, and the rectifying towers are plate towers.

Claims

1. An apparatus for synthesizing DMAC, comprising: the device comprises a neutralization reactor, heating equipment, a membrane separator, condensing equipment, vacuum equipment and refining equipment, wherein the outlet end of the neutralization reactor is connected with the inlet end of the heating equipment; the refining equipment is two rectifying towers connected in series; the rectifying tower is a packed tower or a plate tower; the neutralization reactor is a reaction kettle or a tubular reactor.