Preparation device and preparation method of N,N-dibutyl formamide
By integrating the design of the catalytic reaction distillation column, the efficient preparation of N,N-dibutylformamide was achieved, solving the problems of high energy consumption and low yield in the existing technology, and realizing the large-scale production of high-purity products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG HUALU HENGSHENG GRP DEHUA DESIGN & RES CO LTD
- Filing Date
- 2026-02-13
- Publication Date
- 2026-05-26
AI Technical Summary
Existing methods for preparing N,N-dibutylformamide involve high energy consumption, large equipment investment, and low yield, and there are no reports of large-scale production of the methyl formate method.
The integrated design of the catalytic reaction distillation column is adopted. By combining the first, second and third distillation columns, the reaction and separation are carried out using the catalyst bed. Combined with the use of condensers and reboilers, the efficient separation of reactants and the preparation of high-purity products are achieved.
It improves reaction efficiency and production capacity, reduces energy consumption and equipment wear, and produces high-purity N,N-dibutylformamide with a purity of over 99%, filling the gap in large-scale production using the methyl formate method.
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Figure CN122076048A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic chemical technology and relates to an apparatus and method for preparing N,N-dibutylformamide. Background Technology
[0002] N,N-Dibutylformamide has the molecular formula C9H. 19 NO, with a boiling point of 240℃, is a formamide compound and exhibits the characteristics of formamide compounds. N,N-Dibutylformamide, as a chemical intermediate, plays an important role in pharmaceutical production and the chemical industry. In particular, its unique chemical structure makes it a good solvent in the polymer industry, and its selectivity in the solubility of different substances allows it to be used in the separation and extraction of substances.
[0003] Traditional methods for preparing N,N-dibutylformamide all employ a reaction-separation process, which is energy-intensive, requires significant equipment investment, and has low yields. Currently, there are few reports on the process and equipment for preparing N,N-dibutylformamide using the methyl formate method. Summary of the Invention
[0004] The primary objective of this invention is to provide an apparatus for preparing N,N-dibutylformamide, which can produce high-purity N,N-dibutylformamide with high reaction efficiency and production capacity, short preparation time, low methyl formate loss, low equipment wear, low energy consumption, and safe and stable production.
[0005] To achieve this objective, in a basic embodiment, the present invention provides an apparatus for preparing N,N-dibutylformamide, the apparatus comprising a first distillation column, a second distillation column, a third distillation column, and connecting pipelines. The first distillation column is used to pass the reactants methyl formate and dibutylamine into a catalyst bed loaded therein, and the reaction is carried out under the catalysis of the catalyst in the catalyst bed to produce N,N-dibutylformamide and methanol. Methyl formate and methanol are separated at the top of the column, and dibutylamine and N,N-dibutylformamide are separated at the bottom of the column. The second distillation column is used to distill and separate a portion of the product from the top of the first distillation column, obtaining methyl formate at the top and methanol at the bottom. The third distillation column is used to distill and separate a portion of the product from the bottom of the first distillation column, obtaining dibutylamine at the top and N,N-dibutylformamide at the bottom.
[0006] In a preferred embodiment, the present invention provides an apparatus for preparing N,N-dibutylformamide, wherein the apparatus further includes a condenser disposed at the top of the first distillation column, the second distillation column, and / or the third distillation column, and / or a reboiler disposed at the bottom of the column. The condenser is used to condense the corresponding top product of the tower; The reboiler is used to heat and reboil the corresponding bottom portion of the product.
[0007] In a preferred embodiment, the present invention provides an apparatus for preparing N,N-dibutylformamide, wherein the connecting pipelines include top reflux pipelines corresponding to the condenser at the top of the first distillation column, the second distillation column, and / or the third distillation column, and / or bottom reflux pipelines corresponding to the reboiler. The aforementioned top reflux pipeline is used to return a portion of the top product condensed by the condenser back to the top of the tower. The bottom reflux pipeline is used to return a portion of the bottom product from the reboiler after heating and reboiling to the bottom of the tower.
[0008] In a preferred embodiment, the present invention provides an apparatus for preparing N,N-dibutylformamide, wherein the connecting pipeline includes a methyl formate reflux pipeline for refluxing the methyl formate collected from the top portion of the second distillation column back to the first distillation column for reaction.
[0009] In a preferred embodiment, the present invention provides an apparatus for preparing N,N-dibutylformamide, wherein the connecting pipeline includes a dibutylamine reflux pipeline for refluxing the dibutylamine collected from the top portion of the third distillation column back to the first distillation column for reaction.
[0010] The second objective of this invention is to provide a method for preparing N,N-dibutylformamide that enables the preparation of high-purity N,N-dibutylformamide with high reaction efficiency and production capacity, short preparation time, low methyl formate loss, low equipment wear, low energy consumption, and safe and stable production.
[0011] To achieve this objective, in a basic embodiment, the present invention provides a method for preparing N,N-dibutylformamide, the method utilizing the preparation apparatus described above, comprising the following steps: (1) Start the first distillation column and introduce the reactants methyl formate and dibutylamine. The reaction is carried out under the catalysis of the catalyst loaded in the catalyst bed of the first distillation column to produce N,N-dibutylformamide and methanol. (2) Part of the product from the top of the first distillation column enters the second distillation column for distillation separation, and methyl formate is obtained at the top of the column and methanol is obtained at the bottom of the column; (3) Part of the product from the bottom of the first distillation column enters the third distillation column for distillation separation, and dibutylamine is obtained at the top of the column and N,N-dibutylformamide is obtained at the bottom of the column.
[0012] In a preferred embodiment, the present invention provides a method for preparing N,N-dibutylformamide, wherein in step (1), the catalyst is a solid-phase catalyst selected from one or more titanium-based catalysts.
[0013] In a preferred embodiment, the present invention provides a method for preparing N,N-dibutylformamide, wherein in step (1), methyl formate is introduced into the lower part of the catalyst bed and dibutylamine is introduced into the upper part of the catalyst bed.
[0014] In a preferred embodiment, the present invention provides a method for preparing N,N-dibutylformamide, wherein in step (1), the first distillation column has a theoretical plate number of 5-30, a feed temperature of 40-80℃, a feed pressure of 0.4-0.6 MPa.G, a feed molar ratio of methyl formate to dibutylamine of 0.5-4:1, a column top temperature of 30-70℃, a column top pressure of 0.1-0.2 MPa.G, a column top reflux ratio of 0.5-5:1, a column bottom temperature of 100-200℃, a column bottom pressure of 0.2-0.3 MPa.G, and a column bottom reflux ratio of 0.5-5:1.
[0015] In a preferred embodiment, the present invention provides a method for preparing N,N-dibutylformamide, wherein in step (2), the second distillation column has a theoretical plate number of 5-30, a feed temperature of 30-40℃, a feed pressure of 0.4-0.6 MPa.G, a top temperature of 30-60℃, a top pressure of 0.1-0.2 MPa.G, a top reflux ratio of 0.4-4:1, a bottom temperature of 80-120℃, a bottom pressure of 0.15-0.3 MPa.G, and a bottom reflux ratio of 0.4-4:1.
[0016] In a preferred embodiment, the present invention provides a method for preparing N,N-dibutylformamide, wherein in step (3), the third distillation column has a theoretical plate number of 5-30, a feed temperature of 100-150℃, a feed pressure of 0.4-0.5 MPa.G, a top temperature of 50-80℃, a top pressure of -0.1-0.1 MPa.G, a top reflux ratio of 0.5-4:1, a bottom temperature of 150-220℃, a bottom pressure of -0.05-0.2 MPa.G, and a bottom reflux ratio of 0.5-4:1.
[0017] The beneficial effects of the present invention are that, by using the N,N-dibutylformamide preparation apparatus and preparation method of the present invention, high-purity N,N-dibutylformamide can be prepared with high reaction efficiency and production capacity, short preparation time, low methyl formate loss, low equipment wear, low energy consumption, and safe and stable preparation.
[0018] This invention uses methyl formate and dibutylamine as raw materials, and performs reaction and distillation in a catalytic reactive distillation column (i.e., the first distillation column) to prepare N,N-dibutylformamide. The catalytic reactive distillation column simultaneously carries out the reaction and distillation in one device, separating the reactants and products in a timely manner. This not only greatly improves the product yield but also utilizes the heat of reaction to supply the product separation, achieving energy conservation. More importantly, it fills the gap in the large-scale production of N,N-dibutylformamide using the methyl formate method, and the purity of the obtained N,N-dibutylformamide can reach over 99%.
[0019] The beneficial effects of this invention are specifically reflected in: (1) In the process of preparing N,N-dibutylformamide by methyl formate, the traditional preparation mode of first synthesizing and then separating is abandoned. A catalytic reaction distillation column is introduced in the reaction process, and the reaction zone and the distillation section are designed as an integrated unit, which reduces equipment investment and operating costs. (2) The introduction of catalytic reaction distillation column not only increases the selectivity and conversion rate of reaction and greatly improves the product yield, but also can use the heat of reaction to supply product separation, thus achieving the purpose of energy saving; (3) The present invention uses a catalytic reaction distillation tower plus two other distillation towers to obtain N,N-dibutylformamide with a purity of over 99%, which fills the gap in the large-scale production of N,N-dibutylformamide by the methyl formate method. Attached Figure Description
[0020] Figure 1The following is an exemplary description of the composition and material flow diagram of the apparatus for preparing N,N-dibutylformamide according to the present invention. The apparatus comprises a first distillation column 1, a second distillation column 2, a third distillation column 3, condensers, reboilers, and connecting pipelines. In terms of material flow, A represents methyl formate, B represents dibutylamine, C represents methyl formate and methanol, D represents dibutylamine and N,N-dibutylformamide, E represents methyl formate, F represents methanol, G represents dibutylamine, and H represents N,N-dibutylformamide. Detailed Implementation
[0021] The exemplary structure of the apparatus for preparing N,N-dibutylformamide of the present invention is as follows: Figure 1 As shown, it includes a first distillation column 1, a second distillation column 2, a third distillation column 3, each condenser, each reboiler, and each connecting pipeline.
[0022] The first distillation column 1 is used to pass the reactants methyl formate and dibutylamine into the catalyst bed 4 loaded therein. Under the catalysis of the titanium-based catalyst in the catalyst bed 4, the reaction produces N,N-dibutylformamide and methanol. Methyl formate and methanol are separated at the top of the column, and dibutylamine and N,N-dibutylformamide are separated at the bottom of the column.
[0023] The second distillation column 2 is used to distill and separate a portion of the product from the top of the first distillation column 1, obtaining methyl formate at the top and methanol at the bottom.
[0024] The third distillation column 3 is used to distill and separate a portion of the product from the bottom of the first distillation column 1, obtaining dibutylamine at the top and N,N-dibutylformamide at the bottom.
[0025] The first distillation column 1, the second distillation column 2, and the third distillation column 3 are all equipped with condensers at the top and reboilers at the bottom. The condensers are used to condense the corresponding top product; the reboilers are used to heat and reboil the corresponding bottom product.
[0026] The first distillation column 1, the second distillation column 2, and the third distillation column 3 are all equipped with top reflux lines corresponding to the condensers, and bottom reflux lines corresponding to the reboilers. The top reflux lines are used to return a portion of the top product condensed in the condenser to the top of the column; the bottom reflux lines are used to return a portion of the bottom product reboiled in the reboiler to the bottom of the column.
[0027] The connecting pipeline includes a methyl formate reflux pipeline, which is used to reflux the methyl formate collected from the top of the second distillation column 2 back to the first distillation column 1 for reaction.
[0028] The connecting pipeline includes a dibutylamine reflux pipeline, which is used to reflux the dibutylamine collected from the top of the third distillation column 3 back to the first distillation column 1 for reaction.
[0029] Examples of applications of the exemplary production method using the above-described exemplary preparation apparatus are as follows.
[0030] (1) Catalytic reaction distillation: Start the first distillation column 1 and introduce the reactants methyl formate (18.2t / h 303kmol / h) and dibutylamine (14.3t / h 100kmol / h) (the reactant methyl formate is introduced into the lower part of the catalyst bed 4, and the reactant dibutylamine is introduced into the upper part of the catalyst bed 4). Under the catalysis of the solid titanium-based catalyst (with active alumina as a porous substrate, titanium monoxide as an auxiliary active material, and lanthanum oxide as an active material attached to the surface of titanium monoxide) loaded in the catalyst bed 4 in the middle of the first distillation column 1, N,N-dibutylformamide and methanol are produced. (2) Methanol removal: Part of the product from the top of the first distillation column 1 enters the second distillation column 2 from the middle for distillation separation. Methyl formate is separated at the top of the column and methanol is separated at the bottom of the column. The methanol is collected and sent to the methanol storage tank. (3) Product extraction: Part of the product extracted from the bottom of the first distillation column 1 enters the third distillation column 3 from the middle for distillation separation. Dibutylamine is obtained at the top of the column, and N,N-dibutylformamide is obtained at the bottom of the column. The N,N-dibutylformamide is extracted and sent to the product storage tank.
[0031] in: In step (1), the theoretical number of plates in the first distillation column 1 is 5-30, the feed temperature is 40-80℃, the feed pressure is 0.4-0.6 MPa.G, the top temperature is 30-70℃, the top pressure is 0.1-0.2 MPa.G, the top reflux ratio is 0.5-5:1, the bottom temperature is 100-200℃, the bottom pressure is 0.2-0.3 MPa.G, and the bottom reflux ratio is 0.5-5:1. In step (2), the theoretical number of plates in the second distillation column 2 is 5-30, the feed temperature is 30-40℃, the feed pressure is 0.4-0.6 MPa.G, the top temperature is 30-60℃, the top pressure is 0.1-0.2 MPa.G, the top reflux ratio is 0.5-4:1, the bottom temperature is 80-120℃, the bottom pressure is 0.15-0.3 MPa.G, the bottom reflux ratio is 0.5-4:1, and the proportion of methyl formate refluxed in the methyl formate reflux pipeline to the total methyl formate separated at the top of the column is 0.4. In step (3), the theoretical number of plates in the third distillation column 3 is 5-30, the feed temperature is 100-150℃, the feed pressure is 0.4-0.5Mpa.G, the top temperature is 50-80℃, the top pressure is -0.1-0.1Mpa.G, the top reflux ratio is 0.5-4:1, the bottom temperature is 150-220℃, the bottom pressure is -0.05-0.2Mpa.G, the bottom reflux ratio is 0.5-4:1, and the proportion of dibutylamine refluxed in the dibutylamine reflux pipeline to the total dibutylamine separated at the top of the column is 0.5.
[0032] Using the above production method, 7.4 t / h of methyl formate with a purity of 99% is obtained at the top of the second distillation column 2, and 4.2 t / h of methanol with a purity of 99% is obtained at the bottom of the column; 0.16 kg / h of dibutylamine with a purity of 99.9% is obtained at the top of the third distillation column 3, and 20.74 t / h of N,N-dibutylformamide with a purity of 99% is obtained at the bottom of the column.
[0033] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention is also intended to include these modifications and variations. The above embodiments or implementations are merely illustrative examples of this invention, and it can also be implemented in other specific ways or forms without departing from its gist or essential characteristics. Therefore, the described embodiments should be considered illustrative rather than limiting in any respect. The scope of this invention should be defined by the appended claims, and any changes equivalent to the intent and scope of the claims should also be included within the scope of this invention.
Claims
1. An apparatus for preparing N,N-dibutylformamide, characterized in that: The preparation apparatus includes a first distillation column, a second distillation column, a third distillation column, and connecting pipelines. The first distillation column is used to pass the reactants methyl formate and dibutylamine into a catalyst bed loaded therein, and the reaction is carried out under the catalysis of the catalyst in the catalyst bed to produce N,N-dibutylformamide and methanol. Methyl formate and methanol are separated at the top of the column, and dibutylamine and N,N-dibutylformamide are separated at the bottom of the column. The second distillation column is used to distill and separate a portion of the product from the top of the first distillation column, obtaining methyl formate at the top and methanol at the bottom. The third distillation column is used to distill and separate a portion of the product from the bottom of the first distillation column, obtaining dibutylamine at the top and N,N-dibutylformamide at the bottom.
2. The preparation apparatus according to claim 1, characterized in that: The preparation apparatus further includes condensers installed at the top of the first distillation column, the second distillation column, and / or the third distillation column, and / or reboilers installed at the bottom of the columns. The condenser is used to condense the corresponding top product of the tower; The reboiler is used to heat and reboil the corresponding bottom portion of the product.
3. The preparation apparatus according to claim 2, characterized in that: The connecting pipelines include top reflux pipelines corresponding to the condenser at the top of the first distillation column, the second distillation column, and / or the third distillation column, and bottom reflux pipelines corresponding to the reboiler. The aforementioned top reflux pipeline is used to return a portion of the top product condensed by the condenser back to the top of the tower. The bottom reflux pipeline is used to return a portion of the bottom product from the reboiler after heating and reboiling to the bottom of the tower.
4. The preparation apparatus according to claim 1, characterized in that: The connecting pipeline includes a methyl formate reflux pipeline, used to reflux the methyl formate collected from the top of the second distillation column back to the first distillation column for reaction.
5. The preparation apparatus according to claim 1, characterized in that: The connecting pipeline includes a dibutylamine reflux pipeline, used to reflux the dibutylamine collected from the top portion of the third distillation column back to the first distillation column for reaction.
6. A method for preparing N,N-dibutylformamide, characterized in that, The preparation method utilizes the preparation apparatus according to any one of claims 1-5, and includes the following steps: (1) Start the first distillation column and introduce the reactants methyl formate and dibutylamine. The reaction is carried out under the catalysis of the catalyst loaded in the catalyst bed of the first distillation column to produce N,N-dibutylformamide and methanol. (2) Part of the product from the top of the first distillation column enters the second distillation column for distillation separation, and methyl formate is obtained at the top of the column and methanol is obtained at the bottom of the column; (3) Part of the product from the bottom of the first distillation column enters the third distillation column for distillation separation, and dibutylamine is obtained at the top of the column and N,N-dibutylformamide is obtained at the bottom of the column.
7. The preparation method according to claim 6, characterized in that: In step (1), the catalyst is a solid-phase catalyst, selected from one or more titanium-based catalysts.
8. The preparation method according to claim 6, characterized in that: In step (1), the first distillation column has a theoretical plate number of 5-30, a feed temperature of 40-80℃, a feed pressure of 0.4-0.6 MPa.G, a feed molar ratio of methyl formate and dibutylamine of 0.5-4:1, a top temperature of 30-70℃, a top pressure of 0.1-0.2 MPa.G, a top reflux ratio of 0.5-5:1, a bottom temperature of 100-200℃, a bottom pressure of 0.2-0.3 MPa.G, and a bottom reflux ratio of 0.5-5:
1.
9. The preparation method according to claim 6, characterized in that: In step (2), the second distillation column has a theoretical number of 5-30 plates, a feed temperature of 30-40℃, a feed pressure of 0.4-0.6 MPa.G, a top temperature of 30-60℃, a top pressure of 0.1-0.2 MPa.G, a top reflux ratio of 0.4-4:1, a bottom temperature of 80-120℃, a bottom pressure of 0.15-0.3 MPa.G, and a bottom reflux ratio of 0.4-4:
1.
10. The preparation method according to claim 6, characterized in that: In step (3), the third distillation column has a theoretical plate number of 5-30, a feed temperature of 100-150℃, a feed pressure of 0.4-0.5 MPa.G, a top temperature of 50-80℃, a top pressure of -0.1-0.1 MPa.G, a top reflux ratio of 0.5-4:1, a bottom temperature of 150-220℃, a bottom pressure of -0.05-0.2 MPa.G, and a bottom reflux ratio of 0.5-4:1.