阅读说明：本技术 一种甲醇钠生产装置及方法 (Sodium methoxide production device and method ) 是由 刘玉花 张志恒 张倩瑜 李燕 孙晓英 王双平 于 2020-05-14 设计创作，主要内容包括：本发明提供一种甲醇钠生产装置及方法,其中装置的反应精馏塔,用于醇碱溶液与甲醇反应生成甲醇钠溶液、水与甲醇钠溶液的分离,甲醇钠溶液产品从反应精馏塔塔釜采出；甲醇精馏塔,用于甲醇和水的精密分离,塔釜废水达标排放,塔顶甲醇循环利用；压缩机,用于甲醇精馏塔顶的甲醇蒸汽被升压升温再次进入反应精馏塔,使甲醇能够在反应精馏塔和甲醇精馏塔之间循环利用。本发明的有益效果：甲醇精馏塔塔顶的甲醇蒸汽进入压缩机,经压缩机压缩升温后,一部分作为反应精馏塔塔釜的甲醇气相进料,进入反应精馏塔,另一部分作为甲醇精馏塔中间再沸器的热源,与中间再沸器换热后,再经冷却后,作为塔顶回流,返回甲醇精馏塔,流程短、能耗低、投资少。(The invention provides a sodium methoxide production device and a method, wherein a reaction rectifying tower of the device is used for generating a sodium methoxide solution by the reaction of an alcohol alkali solution and methanol, separating water from the sodium methoxide solution, and extracting a sodium methoxide solution product from a tower kettle of the reaction rectifying tower; the methanol rectifying tower is used for precisely separating methanol and water, the wastewater at the tower bottom is discharged after reaching the standard, and the methanol at the tower top is recycled; the compressor is used for boosting the pressure and raising the temperature of methanol steam at the top of the methanol rectifying tower and then enabling the methanol steam to enter the reaction rectifying tower again, so that the methanol can be recycled between the reaction rectifying tower and the methanol rectifying tower. The invention has the beneficial effects that: the methanol vapor at the top of the methanol rectifying tower enters a compressor, after the temperature of the methanol vapor is raised by the compression of the compressor, one part of the methanol vapor enters the reactive rectifying tower as the methanol gas phase feeding of the tower kettle of the reactive rectifying tower and enters the reactive rectifying tower, the other part of the methanol vapor is used as the heat source of an intermediate reboiler of the methanol rectifying tower, exchanges heat with the intermediate reboiler, is cooled and then is used as the top reflux of the tower and returns to the methanol rectifying tower, and the method has the advantages of short flow, low energy consumption and.)

1. A sodium methoxide production device comprises a reaction rectifying tower, a methanol rectifying tower and a compressor which are connected through pipelines, and is characterized in that the reaction rectifying tower is used for generating a sodium methoxide solution through the reaction of an alcohol alkali solution and methanol, and separating water from the sodium methoxide solution, wherein a sodium methoxide solution product is extracted from a tower kettle of the reaction rectifying tower;

the methanol rectifying tower is used for precisely separating methanol and water, the wastewater at the tower bottom is discharged after reaching the standard, and the methanol at the tower top is recycled;

the compressor is used for boosting and heating the methanol steam at the top of the methanol rectifying tower, and a part of the methanol steam enters the reaction rectifying tower, so that the methanol can be recycled between the reaction rectifying tower and the methanol rectifying tower.

2. The sodium methoxide production device according to claim 1, wherein a second gas phase outlet is arranged at the top of the reaction rectifying tower, a second gas phase inlet is arranged on the methanol rectifying tower, and the second gas phase outlet of the reaction rectifying tower is connected with the second gas phase inlet of the methanol rectifying tower through a second pipeline;

the top of the methanol rectifying tower is provided with a first gas phase outlet, the rectifying tower of the reaction tower is provided with a first gas phase inlet, and the first gas phase outlet of the methanol rectifying tower is connected with a gas inlet of the first gas phase inlet of the rectifying tower of the reaction tower through a first pipeline; the first pipeline is provided with a compressor.

3. The sodium methoxide production apparatus according to claim 1 or 2, wherein an intermediate reboiler heat exchange pipeline is arranged on the first pipeline, a lateral line is arranged on the methanol rectification column, an intermediate reboiler is arranged at a position where the intermediate reboiler heat exchange pipeline and the lateral line are staggered, the intermediate reboiler heat exchange pipeline exchanges heat with the lateral line through the intermediate reboiler, and the methanol extracted from the lateral line enters the intermediate reboiler, is heated by the intermediate reboiler, and then returns to the methanol rectification column as reflux methanol.

4. The apparatus for producing sodium methoxide of claim 3, wherein said apparatus is a rotary press. The middle reboiler heat exchange pipeline is arranged behind the middle reboiler and sequentially provided with a cooler, a reflux tank and a reflux pump, and the middle reboiler heat exchange pipeline is connected with a first liquid phase inlet at the top of the methanol rectifying tower.

5. The apparatus for producing sodium methoxide of claim 3, wherein a reboiler line is disposed at the bottom of the methanol rectification column, and a reboiler is disposed on the reboiler line;

the methanol rectifying tower is characterized in that methanol is fed into a tower kettle reboiler from a tower kettle of the methanol rectifying tower and returns to the tower kettle of the methanol rectifying tower through the tower kettle reboiler, and the tower kettle of the methanol rectifying tower is high-purity water and can be directly discharged up to the standard.

6. The apparatus for producing sodium methoxide as claimed in claim 1, 2, 4 or 5, wherein a coil is disposed at the bottom of said reactive distillation column, low-pressure steam is used as heat source of said reactive distillation column and enters said coil from the bottom of said column, and said steam condensate is extracted from the bottom of said coil.

7. A method for producing sodium methoxide is characterized by comprising the following steps: carrying out reactive distillation on the alcohol alkali solution and methanol in a reactive distillation tower, and obtaining a qualified sodium methoxide solution product at the tower bottom of the reactive distillation tower;

the water-containing methanol steam extracted from the top of the reactive distillation tower enters a methanol distillation tower;

after the hydrous methanol steam is rectified and separated by the methanol rectifying tower, high-purity methanol steam is obtained at the top of the methanol rectifying tower, and wastewater is obtained at the bottom of the methanol rectifying tower;

and (3) the methanol vapor at the top of the methanol rectifying tower enters a compressor, and after the methanol vapor is compressed and heated by the compressor, a part of the methanol vapor enters the reactive rectifying tower as the methanol gas-phase feed of the tower kettle of the reactive rectifying tower.

8. The method for producing sodium methoxide according to claim 7, wherein the methanol vapor at the top of the methanol rectification tower enters a compressor, after the temperature of the methanol vapor is raised by the compression of the compressor, the other part of the methanol vapor is used as a heat source of an intermediate reboiler of the methanol rectification tower, exchanges heat with the intermediate reboiler, is cooled, is used as top reflux, and returns to the methanol rectification tower.

9. The process for producing sodium methoxide of claim 7, wherein said high-purity methanol vapor is methanol vapor of more than 99.95% (wt); the content of methanol in the wastewater is less than 0.15 percent (wt);

the operating pressure of the reaction rectifying tower is 120-210 KpaA, and the temperature in the tower is 75-120 ℃;

the operating pressure of the methanol rectifying tower is 110-200 KpaA, and the temperature in the tower is 65-120 ℃;

the compression ratio of the compressor is 1.8-2.2.

10. The method for producing sodium methoxide of claim 7, wherein the alcohol-base solution and methanol are subjected to reactive distillation in a reactive distillation column, and the qualified sodium methoxide solution product obtained at the bottom of the reactive distillation column is obtained by clarifying the NaOH methanol solution, pumping the clarified NaOH methanol solution to the upper part of the reactive distillation column, and carrying out countercurrent contact reaction between the NaOH methanol solution flowing from top to bottom and the methanol vapor flowing from top in the reactive distillation column to obtain a mixture of sodium methoxide and methanol/water.

Technical Field

The invention relates to the technical field of chemical mass transfer and separation, in particular to a sodium methoxide production device and method.

Background

Sodium methoxide has wide application, is mainly used in the pharmaceutical industry and is used as an important raw material for synthesizing sulfonamides such as sulfadiazine, sulfamethoxazole, sulfonamide synergist and the like; used in the pesticide production and oil processing industry, used as a condensing agent, a chemical reagent, a fat ester exchange catalyst for edible oil treatment and the like in organic synthesis; also, it is widely used as an analytical reagent in the industries of perfumes, dyes, and the like.

The traditional industrial production equipment for sodium methoxide mainly comprises a reaction tower, a rectifying tower and a recovery tower, wherein the reaction tower is mainly used for synthesizing sodium methoxide from alkali and methanol, the rectifying tower is mainly used for recovering methanol which does not participate in reaction and recycling, and the recovery tower is mainly used for further separating dilute methanol solution from water. The traditional sodium methoxide production equipment and process have high energy consumption and long process, and how to save energy, reduce consumption and simplify the process becomes the key point of the research on sodium methoxide production devices.

The device and the method for producing sodium methoxide through mechanical vapor recompression are provided in patent CN103288593A, namely, mechanical vapor recompression sodium methoxide production device and method, the device adopts a first compressor and a second compressor, methanol vapor at the top of a methanol rectifying tower is boosted by the compressor and enters a reaction rectifying tower again, so that the methanol vapor can be recycled between the reaction rectifying tower and the methanol rectifying tower, the energy consumption of the device is saved, but the discharge of a rectifying tower kettle is still dilute methanol solution, namely mixed solution of methanol and water, and the dilute methanol device is required to be further processed; in addition, the two compressors occupy larger area and the equipment investment cost is increased. In patent CN105884578A "a method and apparatus for producing sodium methoxide at high temperature and high pressure", in order to make the gas phase temperature at the top of the methanol rectifying tower meet the requirement of the reactive rectifying tower, the methanol rectifying tower should be a high-pressure tower, so the energy consumption is very high. Patent CN110551003A "a system and process for preparing sodium methoxide by using heat pump compression circulation double towers" proposes that the methanol rectifying tower is only compressed at the top of the tower to provide heat for the reaction rectifying tower, and methanol vapor generated by the methanol rectifying tower is not fully utilized.

Disclosure of Invention

In order to solve the problems, the invention provides a sodium methoxide production device and a sodium methoxide production method, wherein a sodium methoxide production system comprises a rectifying tower and a methanol rectifying tower which are connected, and an alcoholic alkali solution and methanol are reacted in a reaction rectifying tower to generate a sodium methoxide solution; the methanol rectifying tower realizes the precise separation of methanol and water, the wastewater at the tower bottom is discharged after reaching the standard, and the methanol at the tower top is recycled. The sodium methoxide production system and method include that alcohol alkali solution and methanol are subjected to reactive distillation in a reactive distillation tower, a sodium methoxide solution product is obtained at the tower bottom, and hydrous methanol steam extracted from the tower top enters a methanol distillation tower; after the methanol vapor containing water is rectified and separated by a methanol rectifying tower, the methanol vapor with the purity of more than 99.95 percent (wt) is obtained at the tower top, and the wastewater with the methanol content of less than 0.15 percent (wt) is obtained at the tower bottom; the methanol vapor at the top of the methanol rectifying tower enters a compressor, after the temperature of the vapor is raised by the compression of the compressor, one part of the vapor is used as the methanol gas phase feeding of the tower kettle of the reaction rectifying tower and enters the reaction rectifying tower, the other part of the vapor is used as the heat source of an intermediate reboiler of the methanol rectifying tower, exchanges heat with the intermediate reboiler, is cooled and then is used as the top reflux of the tower and returns to the methanol rectifying tower.

The technical scheme of the invention is as follows: a sodium methoxide production device, which comprises a reaction rectifying tower, a methanol rectifying tower and a compressor which are connected by pipelines and is characterized in that,

the reaction rectifying tower is used for generating a sodium methoxide solution through the reaction of an alcohol alkali solution and methanol, separating water from the sodium methoxide solution, and extracting a sodium methoxide solution product from a tower kettle of the reaction rectifying tower;

the methanol rectifying tower is used for precisely separating methanol and water, the wastewater at the tower bottom is discharged after reaching the standard, and the methanol at the tower top is recycled;

the compressor is used for boosting and heating the methanol steam at the top of the methanol rectifying tower, and a part of the methanol steam enters the reaction rectifying tower again, so that the methanol can be recycled between the reaction rectifying tower and the methanol rectifying tower.

Further, the top of the reaction rectifying tower is provided with a second gas phase outlet, the methanol rectifying tower is provided with a second gas phase inlet, and the second gas phase outlet of the reaction rectifying tower is connected with the second gas phase inlet of the methanol rectifying tower through a second pipeline.

The top of the methanol rectifying tower is provided with a first gas phase outlet, the rectifying tower of the reaction tower is provided with a first gas phase inlet, and the first gas phase outlet of the methanol rectifying tower is connected with a gas inlet of the first gas phase inlet of the rectifying tower of the reaction tower through a first pipeline; the first pipeline is provided with a compressor.

Further, a middle reboiler heat exchange pipeline is arranged on the first pipeline, a lateral line is arranged on the methanol rectifying tower, a middle reboiler is arranged at the position where the middle reboiler heat exchange pipeline and the lateral line are staggered, the middle reboiler heat exchange pipeline exchanges heat with the lateral line through the middle reboiler, methanol extracted from the lateral line of the methanol rectifying tower enters the middle reboiler, and the methanol is heated by the middle reboiler and then returns to the methanol rectifying tower as reflux methanol.

Furthermore, the heat exchange pipeline of the middle reboiler is sequentially provided with a cooler, a reflux tank and a reflux pump behind the middle reboiler, and the heat exchange pipeline of the middle reboiler is connected with the first liquid phase inlet at the top of the methanol rectifying tower.

Further, a reboiler circuit is arranged at the tower kettle of the methanol rectifying tower, and a reboiler is arranged on the reboiler circuit;

the methanol rectifying tower is characterized in that methanol is fed into a reboiler at a tower kettle extracted from the tower kettle of the methanol rectifying tower and then is boiled again by the tower kettle and then returns to the tower kettle of the methanol rectifying tower, and the tower kettle of the methanol rectifying tower is high-purity water which can directly reach the discharge standard.

Further, a coil is arranged at the tower bottom of the reactive distillation tower, low-pressure steam is used as a heat source of the tower bottom of the reactive distillation tower and enters the coil in the reactive distillation tower from the tower bottom, and steam condensate is extracted from the lower part of the coil.

Further, the high-purity methanol vapor means methanol vapor of more than 99.95% (wt); the content of methanol in the wastewater is less than 0.15 percent (wt);

further, the operating pressure of the reaction rectifying tower is 120-210 KpaA, and the temperature in the tower is 75-120 ℃;

the operating pressure of the methanol rectifying tower is 110-200 KpaA, and the temperature in the tower is 65-120 ℃;

the compression ratio of the compressor is 1.8-2.2, the operating pressure of the methanol rectifying tower is lower than that of the reaction rectifying tower, and the differential pressure is usually 10-100 Kpa;

the operating pressure of the methanol rectifying tower is lower than that of the reaction rectifying tower, and the pressure difference is usually 10-100 Kpa.

A method for producing sodium methoxide is characterized in that alcohol alkali solution and methanol are subjected to reactive distillation in a reactive distillation tower, and qualified sodium methoxide solution products are obtained at the tower bottom of the reactive distillation tower; the water-containing methanol steam extracted from the top of the reactive distillation tower enters a methanol distillation tower; after the hydrous methanol steam is rectified and separated by the methanol rectifying tower, high-purity methanol steam is obtained at the top of the methanol rectifying tower, and wastewater is obtained at the bottom of the methanol rectifying tower; methanol vapor at the top of the methanol rectifying tower enters a compressor, after the compression and the temperature rise of the compressor, a part of the methanol vapor enters the reactive rectifying tower as methanol gas phase feed at the bottom of the reactive rectifying tower,

and further, methanol steam at the top of the methanol rectifying tower enters a compressor, is compressed by the compressor and heated, and the other part of the methanol steam is used as a heat source of an intermediate reboiler of the methanol rectifying tower, exchanges heat with the intermediate reboiler, is cooled, is used as tower top reflux and returns to the methanol rectifying tower.

Further, the alcohol-alkali solution and methanol are subjected to reactive distillation in a reactive distillation tower, and the qualified sodium methoxide solution product obtained at the tower bottom of the reactive distillation tower specifically means that the NaOH methanol solution is clarified to remove insoluble impurities, then the NaOH methanol solution is pumped to the upper part of the reactive distillation tower, and the NaOH methanol solution flowing from top to bottom in the reactive distillation tower is in countercurrent contact reaction with methanol vapor flowing from top to bottom to generate a sodium methoxide and methanol/water mixture.

The invention has the beneficial effects that: the system is reasonably designed, the alcohol alkali solution and the methanol are subjected to reactive distillation in a reactive distillation tower, a qualified sodium methoxide solution product is obtained at the tower bottom, and the hydrous methanol steam extracted from the tower top enters a methanol distillation tower; after the methanol vapor containing water is rectified and separated by a methanol rectifying tower, the methanol vapor with the purity of more than 99.95 percent (wt) is obtained at the tower top, and the wastewater with the methanol content of less than 0.15 percent (wt) is obtained at the tower bottom; the methanol vapor at the top of the methanol rectifying tower enters a compressor, after the temperature of the vapor is raised by the compression of the compressor, one part of the vapor is used as the methanol gas phase feeding of the tower kettle of the reaction rectifying tower and enters the reaction rectifying tower, the other part of the vapor is used as the heat source of an intermediate reboiler of the methanol rectifying tower, exchanges heat with the intermediate reboiler, is cooled and then is used as the top reflux of the tower and returns to the methanol rectifying tower.

Drawings

Fig. 1 is a schematic structural diagram of a sodium methoxide production apparatus according to the present invention;

FIG. 2 is a flow chart of a process for producing sodium methoxide according to the present invention;

in the drawings: 1. alcohol-alkali solution, 2, low-pressure steam, 3, steam condensate, 4, a reaction rectifying tower, 5, methanol gas containing water, 6, sodium methoxide solution, 7, a methanol rectifying tower, 8, methanol steam, 9, a compressor, 10, compressed methanol steam, 11, methanol steam returning to the reaction rectifying tower, 12, methanol steam entering an intermediate reboiler, 13, an intermediate reboiler, 14, methanol steam after heat exchange, 15, a cooler, 16, cooling methanol, 17, a reflux tank 17, 18, reflux methanol, 19, a reflux pump 19, 20, reflux methanol after pumping, 21, side stream methanol extracted from the reboiler, 22, intermediate methanol returning, 23, tower kettle 24 feeding methanol, 24, tower kettle reboiler, 25, tower kettle reboiler 24 returning methanol, 26, wastewater, 27, a first gas phase outlet, 28, a first gas phase inlet 28, 29, a first pipeline, 30, water, methanol steam condensate, 6, sodium methoxide solution, 7, 8, methanol steam condensate, 9, a compressor, 10, compressed methanol steam after compression, 11, methanol steam returning to the reaction rectifying, A second gas phase outlet, 31, a second gas phase inlet, 32, a second line, 33, an intermediate reboiler heat exchange line, 34, a coil, 35, a side line, 36, a reboiler line.

Detailed Description

The apparatus and method for producing sodium methoxide according to the present invention will be described in detail with reference to the accompanying drawings and examples.

A sodium methoxide production device comprises a reaction rectifying tower 4, a methanol rectifying tower 7 and a compressor 9 which are connected through pipelines, wherein the reaction rectifying tower 4 is used for generating a sodium methoxide solution 6 through the reaction of an alcohol alkali solution 1 and methanol, separating water from the sodium methoxide solution 6, and extracting a product of the sodium methoxide solution 6 from a tower kettle of the reaction rectifying tower 4;

the methanol rectifying tower 7 is used for precisely separating methanol and water, the wastewater at the tower bottom is discharged after reaching the standard, and the methanol at the tower top is recycled;

and the compressor 9 is used for boosting and heating the methanol steam 8 at the top of the methanol rectifying tower 7 and then enters the reaction rectifying tower 4 again, so that the methanol can be recycled between the reaction rectifying tower 4 and the methanol rectifying tower 7.

The top of the reaction rectifying tower 4 is provided with a second gas phase outlet 30, the methanol rectifying tower 7 is provided with a second gas phase inlet 31, and the second gas phase outlet 30 of the reaction rectifying tower 4 is connected with the second gas phase inlet 31 of the methanol rectifying tower 7 through a second pipeline 32.

The top of the methanol rectifying tower 7 is provided with a first gas phase outlet 27, the rectifying tower of the reaction tower is provided with a first gas phase inlet 28, and the first gas phase outlet 27 of the methanol rectifying tower 7 is connected with a gas inlet of the first gas phase inlet 28 of the rectifying tower of the reaction tower through a first pipeline 29; the first line 29 is provided with a compressor 9.

An intermediate reboiler heat exchange pipeline 33 is arranged on the first pipeline 29 through the compressor 9, a lateral line 35 is arranged on the methanol rectifying tower 7, an intermediate reboiler 13 is arranged at the position where the intermediate reboiler heat exchange pipeline 33 and the lateral line 35 are staggered, the intermediate reboiler heat exchange pipeline 33 exchanges heat with the lateral line 35 through the intermediate reboiler, methanol extracted from the lateral line 35 of the methanol rectifying tower 7 enters the intermediate reboiler 13, and after being heated by the intermediate reboiler 13, the methanol returns to the methanol rectifying tower 7 as reflux methanol.

The heat exchange pipeline of the intermediate reboiler 13 is sequentially provided with a cooler 15, a reflux tank 17 and a reflux pump 19 behind the intermediate reboiler 13, and the heat exchange pipeline of the intermediate reboiler 13 is connected with a first liquid phase inlet at the top of the methanol rectifying tower 7.

A reboiler line 36 is arranged at the tower bottom of the methanol rectifying tower 7, and a tower bottom reboiler 24 is arranged on the reboiler line;

feeding methanol into a reboiler 24 of the extraction tower kettle, and returning the methanol to the tower kettle 7 of the methanol rectifying tower through the reboiler 24 of the tower kettle; the tower 7 of the methanol rectifying tower is high-purity water which can be directly discharged after reaching the standard.

The tower bottom of the reaction rectifying tower 4 is provided with a coil pipe 34, low-pressure steam 2 is a heat source of the tower bottom of the reaction rectifying tower 4 and enters the coil pipe 34 in the reaction rectifying tower 4 from the tower bottom, and steam condensate 3 is extracted from the lower part of the coil pipe 34.

A method for producing sodium methoxide, including alcoholic alkali solution 1 and methanol carry on the reactive distillation in the reactive distillation column 4, the tower bottom of the reactive distillation column 4 gets qualified sodium methoxide solution 6 products; the hydrous methanol steam 8 extracted from the top of the reactive distillation tower 4 enters a methanol distillation tower 7; after the hydrous methanol steam 8 is rectified and separated by the methanol rectifying tower 7, high-purity methanol steam 8 is obtained at the top of the methanol rectifying tower 7, and wastewater is obtained at the bottom of the methanol rectifying tower 7; the methanol steam 8 at the top of the methanol rectifying tower 7 enters a compressor 9, after the compression and temperature rise of the compressor 9, one part of the methanol steam enters the reactive rectifying tower 4 as methanol gas phase feeding of the tower kettle of the reactive rectifying tower 4, and the other part of the methanol steam enters the reactive rectifying tower 4 as a heat source of an intermediate reboiler 13 of the methanol rectifying tower 7, exchanges heat with the intermediate reboiler 13, is cooled, and then flows back to the top of the tower as tower reflux to return to the methanol rectifying tower 7.

High purity methanol vapor 8 refers to greater than 99.95% (wt) methanol vapor 8; the content of methanol in the wastewater is less than 0.15 percent (wt);

the operating pressure of the reaction rectifying tower 4 is 120-210 KpaA, the temperature in the tower is 75-120 ℃, the parameter setting is reasonable, and the purity and the production efficiency of the sodium methoxide solution 6 product in the reaction rectifying tower 4 are effectively improved; the operating pressure of the methanol rectifying tower is lower than that of the reaction rectifying tower, and the pressure difference is usually 10-100 Kpa.

The operating pressure of the methanol rectifying tower 7 is 110-200 KpaA, the temperature in the tower is 65-120 ℃, the parameter setting is reasonable, the purity of methanol steam 8 at the top of the methanol rectifying tower 7 is effectively improved, the methanol content of the wastewater in the tower bottom of the methanol rectifying tower 7 is effectively reduced, the methanol can be directly discharged, and the efficient utilization rate of the methanol is also obtained

The compression ratio of the compressor 9 is 1.8-2.2, and the parameters are reasonably set, so that the methanol can be efficiently recycled between the reaction rectifying tower 4 and the methanol rectifying tower 7.

The alcohol-alkali solution 1 and methanol are subjected to reactive distillation in a reactive distillation column 4, and the qualified sodium methoxide solution 6 product obtained in the bottom of the reactive distillation column 4 is specifically obtained by clarifying a NaOH methanol solution to remove insoluble impurities, pumping the NaOH methanol solution to the upper part of the reactive distillation column 4, and carrying out countercurrent contact reaction on the NaOH methanol solution flowing from top to bottom in the reactive distillation column 4 and methanol steam flowing from top to bottom to generate a sodium methoxide and methanol/water mixture.

Compared with the prior art, after the water-containing methanol steam is rectified and separated by the methanol rectifying tower, the methanol steam with the purity of more than 99.95 percent (wt) is obtained at the top of the methanol rectifying tower, the purity of 98-99.80 percent (wt) is obtained at the top of the methanol rectifying tower in the traditional process, and the purity of the methanol steam obtained by adopting the method is effectively improved; the methanol rectifying tower kettle obtains wastewater with the methanol content of less than 0.15 percent (wt), the wastewater with the methanol content of less than 0.2-1 percent (wt) is obtained by the methanol rectifying tower kettle in the traditional process, and a dilute methanol device is required to be further treated, so that the methanol content in the wastewater obtained by adopting the method is effectively reduced, the wastewater can be directly discharged, and the methanol is efficiently utilized; and the methanol vapor at the top of the methanol rectifying tower enters a compressor, after the temperature is raised by the compression of the compressor, one part of the vapor enters the reactive rectifying tower as the methanol gas phase feed of the tower kettle of the reactive rectifying tower and enters the reactive rectifying tower, the other part of the vapor is used as the heat source of an intermediate reboiler 13 of the methanol rectifying tower, exchanges heat with the intermediate reboiler 13, is cooled and then is used as top reflux, and returns to the methanol rectifying tower.

On the basis of the traditional sodium methoxide production process and the double-compressor process, the energy coupling with the compressed methanol steam is realized by combining the heat pump technology and the middle-section heat exchange technology, and the energy consumption of the device is reduced.

The method optimizes the production process of sodium methoxide, reduces energy consumption and investment, promotes sustainable development, and has great economic, environmental and social benefits.