Energy-saving rectification device for coal-to-ethanol
By optimizing the coal-to-ethanol distillation process using multi-effect thermal coupling distillation and heat pump distillation technologies, the problems of high energy consumption and insufficient heat utilization have been solved, achieving low-energy and high-efficiency ethanol production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2026-03-20
AI Technical Summary
The existing coal-to-ethanol distillation process has high energy consumption and insufficient heat utilization, resulting in the failure to fully tap the energy-saving potential of the entire process.
By combining multi-effect thermal coupling distillation technology with heat pump distillation technology, the ethanol refining process is optimized through the partitioned tower structure and multi-effect thermal coupling, and the condensation heat of the steam at the top of each tower is utilized to reduce steam consumption.
This achievement reduced the steam consumption of the entire ethanol distillation process to below 1.6 tons/ton, saving the investment and operating energy consumption of one tower and improving heat utilization efficiency.
Smart Images
Figure CN224009054U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of coal ethanol refining technology, especially to a coal ethanol energy-saving rectification device. BACKGROUND
[0002] Ethanol is an important basic chemical raw material, which is widely used in food, chemical industry, medical and health care and fuel industries.
[0003] At present, the production of ethanol mainly has the grain fermentation route, the petroleum chemical route and the coal chemical route. In the objective environment of global population breaking through 8 billion, it is undoubtedly a waste of food to continue using the method of grain fermentation to produce ethanol. Combined with the basic national conditions of more coal and less oil in China, the process route of coal ethanol will occupy a larger market share in the future, especially through the acetic acid hydrogenation method to produce ethanol, the selectivity of ethanol is high, the moisture is less, and the cost is low.
[0004] The existing coal ethanol refining usually needs to carry out light removal, fat removal, methanol removal and other processes. From the initial raw material to the extracted ethanol product, 4-6 rectification towers are needed. Because the boiling points of ethanol and the components to be removed are close, the operation reflux ratio is high, so the energy consumption of ethanol rectification is always high. In order to reduce energy consumption, part of the device will heat couple 2-3 towers in the system to reduce operation energy consumption. But due to the limitation of the operation temperature difference between the towers, the heat of part of the flow is difficult to be utilized, so the energy-saving potential of the whole process is difficult to be fully tapped, and the optimal energy-saving effect cannot be achieved, so a coal ethanol energy-saving rectification device is proposed to solve the above problems. UTILITY MODEL CONTENTS
[0005] In order to make up for the above shortcomings, the utility model provides a coal ethanol energy-saving rectification device, which aims at improving the problems of high energy consumption in the coal ethanol rectification process and insufficient heat utilization in the system in the prior art.
[0006] In order to achieve the above purpose, the utility model provides the following technical scheme: a coal ethanol energy-saving rectification device, which comprises light removal tower, high-pressure deesterification tower, medium-pressure deesterification tower, ethanol refining tower and methanol deesterification tower connected in sequence, wherein the ethanol refining tower is a partition wall tower structure, which is used for simultaneously separating methanol, ethanol and heavy components.
[0007] Further, the tower top steam of the high-pressure deesterification tower is divided into multiple paths through a pipeline and connected to the light removal tower reboiler, the deesterification tower condensation reboiler and the ethanol refining tower reboiler two respectively, so as to realize multi-effect heat coupling.
[0008] Further, the tower top steam of the medium-pressure deesterification tower is connected to the ethanol refining tower reboiler one as a heat source after being pressurized and heated by the medium-pressure deesterification tower compressor.
[0009] Further, the overhead vapor of the methanol deesterification column is connected to the methanol deesterification column reboiler to realize heat pump rectification after being pressurized and heated by a methanol deesterification column compressor.
[0010] Further, the high-pressure deesterification column and the medium-pressure deesterification column are operated under pressure, and the ethanol refining column is operated under normal pressure.
[0011] Further, the column bottom outlet of the light-removing column is connected to the feed inlet of the high-pressure deesterification column, the column bottom outlet of the high-pressure deesterification column is connected to the feed inlet of the medium-pressure deesterification column, and the column bottom outlet of the medium-pressure deesterification column is connected to the feed side of the ethanol refining column.
[0012] Further, the overhead streams of the high-pressure deesterification column and the medium-pressure deesterification column are combined and sent to the methanol deesterification column to recover methanol.
[0013] Further, the side line outlet of the ethanol refining column is connected to an ethanol dehydration unit, the overhead product is methanol, and the column bottom product is heavy components.
[0014] The coal-to-ethanol energy-saving rectification device has the following beneficial effects:
[0015] 1. In the coal-to-ethanol energy-saving rectification device, the condensation heat of the overhead vapor of each column in the whole process is fully utilized, and only the high-pressure deesterification column needs to be heated by steam, and no additional steam is needed for the other columns.
[0016] 2. In the coal-to-ethanol energy-saving rectification device, a single dividing wall column is applied to the ethanol refining process, so that methanol, ethanol and heavy components can be obtained by using only one dividing wall column, and the investment and operating energy consumption of one column are saved.
[0017] 3. In the coal-to-ethanol energy-saving rectification device, the steam consumption for single-ton coal-to-ethanol rectification can be reduced to less than 1.6 tons. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The coal-to-ethanol energy-saving rectification device has the following beneficial effects:
[0019] LEGEND:
[0020] 1. Light-removing column; 2. Light-removing column reboiler; 3. High-pressure deesterification column; 4. Medium-pressure deesterification column; 5. Deesterification column condensation reboiler; 6. Medium-pressure deesterification column compressor; 7. Ethanol refining column; 8. Ethanol refining column reboiler 1; 9. Ethanol refining column reboiler 2; 10. Methanol deesterification column; 11. Methanol deesterification column compressor; 12. Methanol deesterification column reboiler. DETAILED DESCRIPTION
[0021] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.
[0022] With reference to Figure 1 The present application provides an embodiment: a coal-to-ethanol energy-saving rectification device, comprising a light-removing column 1, a high-pressure de-esterification column 3, a medium-pressure de-esterification column 4, an ethanol refining column 7 and a methanol de-esterification column 10 connected in sequence, wherein the ethanol refining column 7 is a divided wall column structure for simultaneously separating methanol, ethanol and heavy components; the overhead vapor of the high-pressure de-esterification column 3 is divided into multiple paths by a pipeline and connected to the light-removing column reboiler 2, the de-esterification column condensation reboiler 5 and the ethanol refining column reboiler two 9 respectively to realize multi-effect heat coupling; the overhead vapor of the medium-pressure de-esterification column 4 is connected to the ethanol refining column reboiler one 8 as a heat source after being pressurized and heated by the medium-pressure de-esterification column compressor 6; the overhead vapor of the methanol de-esterification column 10 is connected to the methanol de-esterification column reboiler 12 to realize heat pump rectification after being pressurized and heated by the methanol de-esterification column compressor 11; the high-pressure de-esterification column and the medium-pressure de-esterification column are operated under pressure, and the ethanol refining column is operated under normal pressure; the column kettle outlet of the light-removing column 1 is connected to the feed inlet of the high-pressure de-esterification column 3, the column kettle outlet of the high-pressure de-esterification column 3 is connected to the feed inlet of the medium-pressure de-esterification column 4, and the column kettle outlet of the medium-pressure de-esterification column 4 is connected to the feed side of the ethanol refining column 7; the overhead streams of the high-pressure de-esterification column 3 and the medium-pressure de-esterification column 4 are combined and sent to the methanol de-esterification column 10 for further separation; the side line outlet of the ethanol refining column 7 is connected to an ethanol dehydration unit, the overhead of the column is taken out as a methanol product, and the column kettle is taken out as a heavy component.
[0023] Specifically, the crude ethanol feed is first pumped to the light-removing column 1, which is operated at a pressure of 120-170 KPa. Unreacted dimethyl ether and other light components generated during the reaction are collected at the top of the light-removing column 1, and the remaining methanol, ethanol, esters and other heavy components are collected from the bottom of the column and sent to the high-pressure de-esterification column 3. The high-pressure de-esterification column 3 is operated at a pressure of 300-400 KPa. Steam is collected at the top of the column. The steam is divided into three parts. The first part is used to heat the reboiler 2 of the light-removing column, the second part is used to heat the condenser reboiler 5 of the de-esterification column, and the third part is used to heat the reboiler 9 of the ethanol refining column. The condensed liquid after heat exchange is partially returned to the high-pressure de-esterification column 3, and the remaining part is sent to the methanol de-esterification column 10 as feed. The crude ethanol feed from the bottom of the high-pressure de-esterification column 3 is sent to the medium-pressure de-esterification column 4, which is operated at a pressure of 120-170 KPa. Steam is collected at the top of the column. The steam is pressurized and heated by the medium-pressure de-esterification column compressor 6, and then used as a heat source to heat the reboiler 8 of the ethanol refining column. The condensed liquid after heat exchange is partially returned to the medium-pressure de-esterification column 4, and the remaining part is collected and sent to the methanol de-esterification column 10. The feed from the bottom of the medium-pressure de-esterification column 4 is sent to the ethanol refining column 7, which is operated at atmospheric pressure. Methanol product is collected at the top of the column, ethanol gas is collected from the side line of the outlet side and sent to the dehydration unit for dehydration, and heavy component impurities are collected from the bottom of the column. The overhead materials from the high-pressure de-esterification column 3 and the medium-pressure de-esterification column 4 are sent to the methanol de-esterification column 10. The methanol de-esterification column 10 uses heat pump rectification technology. The steam collected at the top of the column is pressurized and heated by the methanol de-esterification column compressor 11, and then used to heat the reboiler 12 of the methanol de-esterification column. Part of the condensed liquid after heating is returned to the methanol de-esterification column 10, and the other part is collected and sent to the ethyl acetate separation unit.
[0024] Working principle: when the device is needed, the crude ethanol raw material is first pumped to the light-removing column 1, the unreacted dimethyl ether and other light components generated in the reaction process are collected from the top of the light-removing column 1, and the remaining methanol, ethanol, esters and other heavy components are collected from the column bottom and sent to the high-pressure de-esterification column 3; the high-pressure de-esterification column 3 is operated under pressure, and the steam at the top is divided into three parts, the first part is used to heat the light-removing column reboiler 2, the second part is used to heat the de-esterification column condensation reboiler 5, and the third part is used to heat the ethanol refining column reboiler 2 9, the condensed liquid after heat exchange is partially returned to the high-pressure de-esterification column 3, and the remaining part is combined with the stream at the top of the medium-pressure de-esterification column 4 and sent to the methanol de-esterification column 10; the crude ethanol material at the column bottom of the high-pressure de-esterification column 3 is sent to the medium-pressure de-esterification column 4; the steam at the top of the medium-pressure de-esterification column 4 is collected and sent to the medium-pressure de-esterification column compressor 6 for pressure boosting to improve the steam temperature, so that it can be used as a heat source to heat the ethanol refining column reboiler 1 8; part of the condensed liquid after heating is returned to the medium-pressure de-esterification column 4, and the remaining part is collected and combined with the stream from the high-pressure de-esterification column 3 and sent to the methanol de-esterification column 10; the column material of the medium-pressure de-esterification column 4 is sent to the ethanol refining column 7, which is a divided wall column, the material enters from the feed side of the divided wall column, the methanol product is collected from the top of the divided wall column, the ethanol gas is collected from the side line of the discharge side and sent to the dehydration unit, and the heavy components are collected from the column bottom; the stream at the top of the high-pressure de-esterification column 3 and the medium-pressure de-esterification column 6 is sent to the methanol de-esterification column 10, the steam at the top of the methanol de-esterification column 10 is pressurized and heated by the methanol de-esterification column compressor 11, and the heated steam is used to heat the methanol de-esterification column reboiler 12 to avoid the use of steam in the methanol de-esterification column 10; part of the condensed liquid after heating is returned to the methanol de-esterification column 10, and the other part is collected as crude ester and sent to the ethyl acetate recovery unit. The methanol product is collected from the column bottom of the methanol de-esterification column 10.
[0025] Finally, it should be pointed out that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. An energy-saving distillation apparatus for coal-to-ethanol production, characterized in that, It includes a light component removal tower (1), a high-pressure deesterification tower (3), a medium-pressure deesterification tower (4), an ethanol purification tower (7), and a methanol deesterification tower (10) connected in sequence, wherein the ethanol purification tower (7) is a partitioned tower structure used to simultaneously separate methanol, ethanol, and heavy components.
2. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The top steam of the high-pressure deesterification tower (3) is divided into multiple streams through pipelines and connected to the reboiler (2) of the light-light removal tower, the condenser-reboiler (5) of the deesterification tower, and the second reboiler (9) of the ethanol refining tower, respectively, to achieve multi-effect thermal coupling.
3. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The top steam of the medium-pressure deesterification tower (4) is pressurized and heated by the medium-pressure deesterification tower compressor (6) and then connected to the reboiler (8) of the ethanol refining tower as a heat source.
4. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The top vapor of the methanol deesterification tower (10) is pressurized and heated by the methanol deesterification tower compressor (11) and then connected to the methanol deesterification tower reboiler (12) to achieve heat pump distillation.
5. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The high-pressure deesterification tower (3) and the medium-pressure deesterification tower (4) are operated under pressure, while the ethanol refining tower (7) is operated under atmospheric pressure.
6. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The bottom outlet of the light removal tower (1) is connected to the feed inlet of the high-pressure deesterification tower (3), the bottom outlet of the high-pressure deesterification tower (3) is connected to the feed inlet of the medium-pressure deesterification tower (4), and the bottom outlet of the medium-pressure deesterification tower (4) is connected to the feed side of the ethanol refining tower (7).
7. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The top streams from the high-pressure deesterification tower (3) and the medium-pressure deesterification tower (4) are combined and sent to the methanol deesterification tower (10) to recover methanol.
8. The energy-saving distillation apparatus for coal-to-ethanol according to claim 1, characterized in that: The side outlet of the ethanol refining tower (7) is connected to the ethanol dehydration unit, and methanol product is drawn from the top of the tower, while heavy components are drawn from the bottom of the tower.