An energy-saving and consumption-reducing separation method for the azeotrope of dimethyl carbonate and methanol

Abstract

The present invention relates to the technical field of azeotrope energy-saving separation, and provides a separation method for energy-saving and consumption-reducing of a dimethyl carbonate and methanol azeotrope, comprising the following steps: S1. After preheating, the first azeotrope of dimethyl carbonate and methanol is fed into the first distillation column, heated and pressurized, and the second azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the remaining third azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into the second distillation column; S2. The second distillation column is heated and pressurized, and the fourth azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the remaining fifth azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into the refining column; S3. After the third azeotrope and the fourth azeotrope are heat-exchanged through a heat exchanger, they are fed into the second distillation column. Through the above technical solution, the problem in the prior art that a large amount of steam is consumed in separating the azeotrope by pressure-variable two-column distillation is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of azeotrope energy-saving separation, and specifically, to a separation method for energy-saving and consumption-reducing of a dimethyl carbonate and methanol azeotrope. Background Art

[0002] Dimethyl carbonate is a low-toxic, environmentally friendly, and widely used organic chemical synthesis raw material. Its molecular structure contains functional groups such as methyl, carbonyl, and methoxy groups, and can undergo various reactions. It can be used as a solvent, gasoline additive, and carbonyl methoxylation reagent. At the same time, as a common component of lithium battery electrolytes, the demand for dimethyl carbonate is also increasing. At present, domestic production methods of dimethyl carbonate include carbonylation, urea method, transesterification process, etc., among which the transesterification method accounts for more than 80% in China.

[0003] The transesterification method for producing dimethyl carbonate uses methanol and propylene (ethylene) carbonate as raw materials to produce dimethyl carbonate. The dimethyl carbonate and methanol formed in the reaction need to be separated from the azeotrope. Currently, the mainstream domestic method is to separate the azeotrope by variable-pressure double-column distillation. The dimethyl carbonate and methanol are separated by series distillation of a pressurized column and an atmospheric column. However, in the separation process, since methanol accounts for 70% in the azeotrope, a large amount of steam is consumed in the separation process, increasing the product cost. Summary of the Invention

[0004] The present invention provides a separation method for energy-saving and consumption-reducing of a dimethyl carbonate and methanol azeotrope, which solves the problem that a large amount of steam is consumed in the separation of the azeotrope by using variable-pressure double-column distillation in the related art.

[0005] The technical solution of the present invention is as follows:

[0006] A separation method for energy-saving and consumption-reducing of a dimethyl carbonate and methanol azeotrope includes the following steps:

[0007] S1. The first azeotrope of dimethyl carbonate and methanol is preheated and then fed into distillation column 1 for heating and pressurization. The second azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the remaining third azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into distillation column 2;

[0008] S2. Distillation column 2 is heated and pressurized. The fourth azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the remaining fifth azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into a refining column;

[0009] S3. After the third azeotrope and the fourth azeotrope are heat-exchanged through a heat exchanger, they are fed into distillation column 2.

[0010] As a further technical solution, in step S1, the pressure of distillation column 1 is 0.2 MpaG - 1.5 MpaG; the bottom temperature of the column is 94°C - 185°C;

[0011] In the step S2, the pressure of the second distillation column is 0.3 MpaG - 1.6 MpaG; the top temperature of the column is 103°C - 190°C.

[0012] As a further technical solution, the temperature difference between the top temperature of the second distillation column and the bottom temperature of the first distillation column is ≥ 5°C;

[0013] As a further technical solution, the methanol content in the first azeotrope is greater than 70 wt%; the methanol content in the third azeotrope is 45 - 65 wt%.

[0014] As a further technical solution, the structures of the first distillation column and the second distillation column are the same, and the first distillation column includes

[0015] a tower body, having a feed inlet, a top product outlet and a bottom product outlet, and the feed inlet is located between the top product outlet and the bottom product outlet;

[0016] a bulk material assembly, rotatably arranged in the tower body and located at the feed inlet, and the bulk material assembly is used for dispersing the first azeotrope passing through the feed inlet; and

[0017] air holes, arranged on the tower body, below the feed inlet, and a plurality of air holes are arranged, and the plurality of air holes are circumferentially arranged on the inner wall of the tower body.

[0018] As a further technical solution, the air holes are used for blowing out the gas of the second azeotrope, and a plurality of air holes blow out gas to form a cylindrical air curtain on the inner wall of the tower body, and the air curtain flows upward.

[0019] As a further technical solution, the bulk material assembly includes

[0020] a rotating support plate, rotatably arranged in the tower body;

[0021] blades, arranged on the rotating support plate, and an included angle exists between the blades and the radius of the rotating support plate, and a plurality of blades are arranged, and the plurality of blades are circumferentially arranged on the rotating support plate;

[0022] a pressing plate, arranged above the blades, and the pressing plate is in a cap-like structure, and a flow hole is formed in the middle of the pressing plate, and the flow hole is communicated with the feed inlet.

[0023] As a further technical solution, the height of the blades gradually decreases in the direction close to the edge of the rotating support plate.

[0024] For a further technical solution, a motor is provided on the first rectification column, and the output shaft of the motor passes through the first rectification column and is connected to the rotating support plate.

[0025] The working principle and beneficial effects of the present invention are as follows:

[0026] 1. The present invention separates the azeotrope of methanol and dimethyl carbonate through two columns and performs thermal coupling on the two columns. The process is fully continuous, the control is simple, the steam consumption is reduced by about half, and the production cost is greatly reduced.

[0027] 2. Part of the gas-phase second azeotrope is accelerated by an air pump and ejected from the air holes to form an air curtain inside the tower body. The liquid azeotrope flowing out of the feed port falls into the flow holes, and then the liquid azeotrope flows out between the rotating blades. The distance between adjacent blades gradually increases along the direction of liquid movement, but the height of the blades gradually decreases along the direction of liquid movement, so that under the action of centrifugal force, the cross-section of the liquid changes from a polygonal cross-section to a flat linear cross-section, making the liquid separated from the rotating support plate present a flat laminar liquid surface, and this liquid surface is thrown towards the inner wall of the tower body. During the process of the liquid surface on the inner wall of the two-way tower body, it is dispersed by the air curtain from bottom to top and is impacted and thrown upwards to become small liquid droplets. The small liquid droplets are quickly vaporized under the state of heating and pressurization inside the tower body to form the second azeotrope. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0029] Figure 1 is a schematic diagram of the process flow of the present invention;

[0030] Figure 2 is a schematic diagram of the structures of the first rectification column and the second rectification column of the present invention;

[0031] Figure 3 is a schematic sectional view of the structures of the first rectification column and the second rectification column of the present invention;

[0032] Figure 4 is a schematic diagram of the structure of the bulk material component of the present invention;

[0033] Figure 5 is a schematic diagram of the structure of the bulk material component (without a pressing plate) of the present invention;

[0034] In the figure: T1 is the first distillation column, T2 is the second distillation column, P1 is the feed pump, P2 is the reflux pump of the first column, P3 is the bottom transfer pump, P4 is the reflux pump of the second column, E1 is the heat exchanger, E2 is the condenser of the first column, E3 is the reboiler, V1 is the reflux drum of the first column, V2 is the reflux drum of the second column, 10 is the column body, 11 is the feed inlet, 12 is the top product outlet, 13 is the bottom product outlet, 20 is the bulk material component, 21 is the rotating support plate, 22 is the blade, 23 is the pressing plate, 231 is the flow-through hole, 30 is the air hole, 40 is the motor. Detailed implementation mode

[0035] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0036] The present invention provides a method for separating azeotrope of dimethyl carbonate and methanol with energy saving and consumption reduction, including the following steps:

[0037] S1. The first azeotrope of dimethyl carbonate and methanol is preheated and then fed into the first distillation column for heating and pressurization. The pressure of the first distillation column is 0.2 MpaG - 1.5 MpaG; the bottom temperature is 94°C - 185°C; the second azeotrope of dimethyl carbonate and methanol is taken out from the top of the column. The composition of the second azeotrope is determined by the pressure. Part of the gaseous material of the second azeotrope is refluxed into the first distillation column through the air hole, and the remaining material is partially taken out after condensation and reflux. The remaining third azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into the second distillation column; the methanol content in the third azeotrope is 45 - 65 wt%.

[0038] S2. The second distillation column is heated and pressurized. The pressure of the second distillation column is 0.3 MpaG - 1.6 MpaG; the top temperature is 103°C - 190°C; the temperature difference between the top temperature of the second distillation column and the bottom temperature of the first distillation column is ≥ 5°C; the fourth azeotrope of dimethyl carbonate and methanol is taken out from the top of the column. The fourth azeotrope enters the heat exchanger in the gas phase to provide heat source for the materials in the first distillation column. The gaseous fourth azeotrope after heat exchange is liquefied and enters the reflux drum of the second distillation column, and part of it is refluxed and part is taken out; the remaining fifth azeotrope of dimethyl carbonate and methanol at the bottom of the column is fed into the refining column.

[0039] S3. After the third azeotrope and the fourth azeotrope are heat exchanged through the heat exchanger, they are fed into the second distillation column.

[0040] The following is an example for a 10,000-ton device for illustration.

[0041] Example 1

[0042] This embodiment proposes a separation method for energy conservation and consumption reduction of the azeotrope of dimethyl carbonate and methanol. The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 9 tons per hour by a feed pump; the pressure in the first distillation column is controlled at 0.5 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 3.7 tons per hour, the temperature at the bottom of the column is about 118 °C, the methanol content in the third azeotrope at the bottom of the column is 59 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 5.3 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump. The pressure in the second distillation column is controlled at 0.8 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 3.5 tons per hour, the temperature at the top of the column is about 133 °C. The fourth azeotrope at the top of the second distillation column is heat-exchanged with the third azeotrope at the bottom of the first distillation column. The fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent process treatment. Compared with the single-pressure tower treatment condition at 0.8 MpaG, the energy consumption is reduced by 49.2%.

[0043] Example 2

[0044] The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 14.5 tons per hour by a feed pump; the pressure in the first distillation column is controlled at 0.2 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 6.5 tons per hour, the temperature at the bottom of the column is about 95 °C, the methanol content in the third azeotrope at the bottom of the column is 63 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 8 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump. The pressure in the second distillation column is controlled at 0.4 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 6.2 tons per hour, the temperature at the top of the column is about 111 °C. The fourth azeotrope at the top of the second distillation column is heat-exchanged with the third azeotrope at the bottom of the first distillation column. The fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent process treatment. Compared with the single-pressure tower treatment condition at 0.4 MpaG, the energy consumption is reduced by 49%.

[0045] Example 3

[0046] The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 7.8 tons per hour by a feed pump; the pressure in the first distillation column is controlled at 0.7 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 3.1 tons per hour, the temperature at the bottom of the column is about 129 °C, the methanol content in the third azeotrope at the bottom of the column is 58 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 4.7 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump, the pressure in the second distillation column is controlled at 1.1 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 2.9 tons per hour, the temperature at the top of the column is about 144 °C, the fourth azeotrope at the top of the second distillation column is heat-exchanged with the third azeotrope at the bottom of the first distillation column, and the fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent processing. Compared with the single-pressure column treatment condition of 1.1 MpaG, the energy consumption is reduced by 49%.

[0047] Example 4

[0048] The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 7.8 tons per hour by a feed pump; the pressure in the first distillation column is controlled at 0.6 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 3.2 tons per hour, the temperature at the bottom of the column is about 124 °C, the methanol content in the third azeotrope at the bottom of the column is 60 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 4.6 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump, the pressure in the second distillation column is controlled at 1.2 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 2.8 tons per hour, the temperature at the top of the column is about 144 °C, the fourth azeotrope at the top of the second distillation column is heat-exchanged with the third azeotrope at the bottom of the first distillation column, and the fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent processing. Compared with the single-pressure column treatment condition of 1.2 MpaG, the energy consumption is reduced by 54.0%.

[0049] Example 5

[0050] The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 7.8 tons per hour by a feed pump; the pressure in the first distillation column is controlled at 0.8 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 3 tons per hour, the temperature at the bottom of the column is about 133 °C, the methanol content in the third azeotrope at the bottom of the column is 57 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 4.8 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump, the pressure in the second distillation column is controlled at 0.9 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 3 tons per hour, the temperature at the top of the column is about 139 °C, the fourth azeotrope at the top of the second distillation column is heat-exchanged with the third azeotrope at the bottom of the first distillation column, and the fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent processing. Compared with the single-pressure column treatment condition of 0.9 MpaG, the energy consumption is reduced by 50.2%.

[0051] Example 6

[0052] The first azeotrope of dimethyl carbonate and methanol is fed to the first distillation column at a flow rate of 8.1 tons per hour by a feed pump; the pressure of the first distillation column is controlled at 0.7 MpaG, the second azeotrope is withdrawn from the top of the column at a rate of 3.2 tons per hour, the temperature at the bottom of the column is about 129 °C, the methanol content in the third azeotrope at the bottom of the column is 58 wt%, and the third azeotrope is withdrawn from the bottom of the column at a rate of 4.9 tons per hour; the third azeotrope flowing out of the first distillation column is fed to the second distillation column by a transfer pump. The pressure of the second distillation column is controlled at 0.9 MpaG, the fourth azeotrope is withdrawn from the top of the column at a rate of 3.1 tons per hour, the temperature at the top of the column is about 139 °C, the fourth azeotrope at the top of the second distillation column exchanges heat with the third azeotrope at the bottom of the first distillation column, and the fifth azeotrope is withdrawn from the bottom of the second distillation column at a rate of 1.8 tons per hour to obtain the crude DMC for subsequent process treatment. Compared with the single-pressure tower treatment condition at 0.9 MpaG, the energy consumption is reduced by 50.8%.

[0053]

[0054] It can be seen that under the condition of obtaining the same crude DMC, by treating the azeotrope of dimethyl carbonate and methanol with a two-column system, compared with the single-column pressurization and heating, about 50% of the energy can be saved, the production cost is greatly reduced, and the effect is remarkable.

[0055] Example 7

[0056] As Figure 1 shown, the first azeotrope of dimethyl carbonate and methanol is sucked into the inlet of the feed pump P1 through the feed pipeline, and then reaches the feed port of the first distillation column T1 through the outlet of the feed pump P1; the outlet 12 at the top of the first distillation column T1 is connected to the inlet of the first column condenser E2, the outlet of the first column condenser E2 is connected to the inlet of the column reflux drum V1, the outlet of the column reflux drum V1 is connected to the inlet of the column reflux pump P2, and the outlet of the column reflux pump P2 is respectively connected to the top reflux port of the first distillation column T1 and the top product withdrawal pipeline; the outlet 13 at the bottom of the first distillation column T1 is respectively connected to the cold-side material inlet of the heat exchanger E1 and the inlet of the bottom transfer pump P3, the cold-side material outlet of the heat exchanger E1 is connected to the bottom return port, and the outlet of the bottom transfer pump P3 is connected to the feed port of the second distillation column T2;

[0057] The top outlet 12 of the second distillation column T2 is connected to the inlet of the hot side material of the heat exchanger E1, the outlet of the hot side material of the heat exchanger E1 is connected to the inlet of the second reflux drum V2, the outlet of the second reflux drum V2 is connected to the inlet of the second reflux pump P4, and the outlet of the second reflux pump P4 is respectively connected to the top outlet 12 of the second distillation column T2 and the top product pipeline; the bottom outlet 13 of the second distillation column T2 is respectively connected to the inlet of the cold side material of the reboiler E3 and the inlet of the bottom product pump P5, the outlet of the cold side material of the reboiler E3 is connected to the bottom return port, and the outlet of the bottom product pump P5 is connected to the bottom product pipeline.

[0058] Example 8

[0059] As Figures 2 - 5 shown, on the basis of Examples 1-6, the structures of the first distillation column and the second distillation column in this example are the same, and the first distillation column includes

[0060] a tower body 10, having a feed inlet 11, a top outlet 12 and a bottom outlet 13, and the feed inlet 11 is located between the top outlet 12 and the bottom outlet 13;

[0061] a bulk material assembly 20, rotatably arranged in the tower body 10, located at the feed inlet 11, and the bulk material assembly 20 is used for dispersing the first azeotrope passing through the feed inlet 11; and

[0062] air holes 30, arranged on the tower body 10, the air holes 30 are located below the feed inlet 11, and a plurality of the air holes 30 are arranged circumferentially on the inner wall of the tower body 10.

[0063] The air holes 30 are used for blowing out the gas of the second azeotrope, and a plurality of the air holes 30 blow out gas to form a cylindrical air curtain on the inner wall of the tower body 10, and the air curtain flows upward.

[0064] The bulk material assembly 20 includes

[0065] a rotating support plate 21, rotatably arranged in the tower body 10;

[0066] vanes 22, arranged on the rotating support plate 21, an angle exists between the vanes 22 and the radius of the rotating support plate 21, and a plurality of the vanes 22 are arranged circumferentially on the rotating support plate 21;

[0067] a pressing plate 23, arranged above the vanes 22, the pressing plate 23 is in a cap-like structure, and a flow hole 231 is formed in the middle of the pressing plate 23, and the flow hole 231 is communicated with the feed inlet 11.

[0068] The height of the blade 22 gradually decreases in the direction close to the edge of the rotating support plate 21.

[0069] A motor 40 is provided on the first rectifying column, and the output shaft of the motor 40 passes through the first rectifying column and is connected to the rotating support plate 21.

[0070] In this embodiment, a rotating material scattering assembly 20 is provided in the tower body 10. The output shaft of the motor 40 is coaxially connected to the rotating support plate 21, and the motor 40 is provided at the bottom of the tower body 10, so that the motor 40 is located outside the tower body 10. When heating and pressurizing operations are carried out inside the tower body 10, the temperature and pressure will not affect the motor 40, ensuring the service life of the motor 40. The motor 40 rotates to drive the rotating support plate 21 to rotate, and the rotating support plate 21 rotates to drive the blades 22 and the pressing plate 23 thereon to rotate, so that the liquid azeotrope flowing out of the feed port 11 falls into the flow holes 231, and then the liquid azeotrope flows out between the rotating blades 22. The distance between adjacent blades 22 gradually increases along the direction of liquid movement, but the height of the blade 22 gradually decreases along the direction of liquid movement, so that under the action of centrifugal force, the cross-section of the liquid changes from a polygonal cross-section to a flat linear cross-section, so that the liquid separated from the rotating support plate 21 forms a flat-layer liquid surface, and the liquid surface is thrown towards the inner wall of the tower body 10. During the process of the liquid surface reaching the inner wall of the two-way tower body 10, it is dispersed by the upward gas curtain from bottom to top, and is impacted and thrown upwards to become small liquid droplets. The small liquid droplets are quickly vaporized under the heating and pressurizing state in the tower body 10 to form a second azeotrope, which flows out from the top outlet 12. Since the whole liquid is stratified and flows out and is impacted into small liquid droplets again, it can be quickly vaporized after absorbing energy, greatly reducing the energy consumption; part of the gaseous second azeotrope is accelerated by an air pump and ejected from the air holes 30 to form a gas curtain in the tower body 10, and the remaining gaseous second azeotrope is the same as in Embodiments 1-6. The gas curtain of the second azeotrope formed circumferentially on the inner wall of the tower body 10 also separates the liquid from the tower body 10, avoiding the adhesion of the liquid on the tower body 10, and at the same time reducing the contact between the liquid azeotrope (liquid methanol and liquid dimethyl carbonate) and the inner wall of the tower body 10, so as to smoothly enter the next rectifying column for separation or for recycling.

[0071] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A separation method for energy conservation and consumption reduction of azeotrope of dimethyl carbonate and methanol, characterized in that, It includes the following steps: S1. The first azeotrope of dimethyl carbonate and methanol is preheated and then fed into the first distillation column, where it is heated and pressurized. The second azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the third azeotrope of dimethyl carbonate and methanol remaining at the bottom of the column is fed into the second distillation column; S2. The second distillation column is heated and pressurized. The fourth azeotrope of dimethyl carbonate and methanol is taken out from the top of the column, and the fifth azeotrope of dimethyl carbonate and methanol remaining at the bottom of the column is fed into the refining column; S3. The third azeotrope and the fourth azeotrope are heat-exchanged through a heat exchanger and then fed into the second distillation column; Among them, in step S1, the pressure of the first distillation column is 0.2 MpaG - 1.5 MpaG; the temperature at the bottom of the column is 94°C - 185°C. In step S2, the pressure of the second distillation column is 0.3 MpaG - 1.6 MpaG; the temperature at the top of the column is 103°C - 190°C; Among them, the temperature difference between the temperature at the top of the second distillation column and the temperature at the bottom of the first distillation column is ≥5°C; Among them, the methanol content in the first azeotrope is greater than 70 wt%; the methanol content in the third azeotrope is 45 - 65 wt%.

2. The separation method for energy conservation and consumption reduction of a dimethyl carbonate and methanol azeotrope according to claim 1, characterized in that, The structures of the first distillation column and the second distillation column are the same. The first distillation column includes a tower body (10) having a feed inlet (11), a top outlet (12) and a bottom outlet (13), and the feed inlet (11) is located between the top outlet (12) and the bottom outlet (13); a bulk material component (20) rotatably arranged in the tower body (10) and located at the feed inlet (11), and the bulk material component (20) is used for dispersing the first azeotrope passing through the feed inlet (11); and air holes (30) provided on the tower body (10), the air holes (30) are located below the feed inlet (11), and a plurality of the air holes (30) are circumferentially arranged on the inner wall of the tower body (10).

3. A separation method for energy conservation and consumption reduction of a dimethyl carbonate and methanol azeotrope according to claim 2, characterized in that, The air holes (30) are used for blowing out the gas of the second azeotrope. The gas blown out by several of the air holes (30) forms a cylindrical air curtain on the inner wall of the tower body (10), and the air curtain flows upward from bottom to top.

4. The separation method for energy conservation and consumption reduction of a dimethyl carbonate and methanol azeotrope according to claim 3, characterized in that, The bulk material component (20) includes a rotating support plate (21) rotatably arranged in the tower body (10); blades (22) provided on the rotating support plate (21), and an angle exists between the blades (22) and the radius of the rotating support plate (21). A plurality of the blades (22) are circumferentially arranged on the rotating support plate (21); a pressing plate (23) provided above the blades (22), the pressing plate (23) is in a cap-like structure, and a flow-through hole (231) is provided in the middle of the pressing plate (23), and the flow-through hole (231) is communicated with the feed inlet (11).

5. A separation method for energy conservation and consumption reduction of a dimethyl carbonate and methanol azeotrope according to claim 4, characterized in that, The height of the blades (22) gradually decreases in the direction close to the edge of the rotating support plate (21).

6. A separation method for energy conservation and consumption reduction of a dimethyl carbonate and methanol azeotrope according to claim 4, characterized in that, A motor (40) is provided on the first distillation column, and the output shaft of the motor (40) passes through the first distillation column and is connected to the rotating support plate (21).

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