Energy-saving production device for absolute ethyl alcohol

Abstract

The utility model relates to an energy-saving production device for absolute ethyl alcohol. The energy-saving production device comprises a dehydrating tower, a recovery tower, an oil-water separator, a raw material ethanol preheater, a dehydrating tower feeding preheater, a dehydrating tower reboiler and a dehydrating tower overhead condenser, raw material ethanol is preheated by a raw material ethanol preheater and a dehydrating tower feeding preheater and then enters a dehydrating tower, absolute ethanol extracted from a dehydrating tower kettle serves as a heat source of the dehydrating tower feeding preheater, and gas-phase azeotrope extracted from the top of the dehydrating tower is condensed by a dehydrating tower top condenser and then enters an oil-water separator; an oil phase of the oil-water separator flows back to the dehydrating tower, a water phase enters a recovery tower, wastewater is extracted from a tower kettle of the recovery tower, a high-heat gas phase extracted from the tower top of the recovery tower is sequentially used as a heat source of a dehydrating tower reboiler and a raw material ethanol preheater, a part of the condensed heat source returns to the recovery tower, and the other part of the condensed heat source enters a dehydrating tower feeding preheater. According to the utility model, absolute ethyl alcohol is obtained in a rectification mode by adopting a double-tower process, so that the energy consumption, the investment cost and the operation cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical distillation and separation, in particular to an energy-saving production device for anhydrous ethanol. Background Art

[0002] Ethanol is an important chemical raw material and organic solvent, which is widely used in fuel, medical, chemical, food and other fields. With the development of science and technology and the continuous expansion of application fields, the demand for anhydrous ethanol is increasing. Since water and ethanol can form low-boiling azeotropes, ordinary distillation can only obtain 95% ethanol, so ordinary distillation cannot obtain anhydrous ethanol with high purity. At present, the methods for preparing anhydrous ethanol include: azeotropic distillation, molecular sieve adsorption method, gas chromatography, reaction method, etc., but they all have some shortcomings, mainly high energy consumption, high production cost, low purity, etc. Utility Model Content

[0003] The utility model aims to solve the deficiencies of the prior art and provide an energy-saving production device for anhydrous ethanol.

[0004] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0005] An energy-saving production device for anhydrous ethanol, comprising a dehydration tower, a recovery tower, an oil-water separator, a raw ethanol preheater, a dehydration tower feed preheater, a dehydration tower reboiler, and a dehydration tower top condenser;

[0006] The upper end of the side wall of the dehydration tower is provided with a preheating raw material ethanol inlet and an oil phase reflux port, the top of the tower is provided with a gas phase azeotrope extraction port, and the bottom of the tower is provided with an anhydrous ethanol extraction port; the upper end of the side wall of the recovery tower is provided with a feed port and a reflux port, the top of the tower is provided with an ethanol / entrainer extraction port, and the bottom of the tower is provided with a wastewater port; the side wall of the oil-water separator is provided with an entrainer inlet and an oil phase extraction port, the top is provided with a gas phase azeotrope condensate inlet, and the bottom is provided with a water phase extraction port; the raw material ethanol preheater is provided with a raw material ethanol primary preheating inlet, a raw material ethanol primary preheating outlet, a primary cooling liquid phase inlet, and a secondary cooling liquid outlet; the dehydration tower feed preheater is provided with a raw material ethanol secondary preheating inlet, a raw material ethanol secondary preheating outlet, an anhydrous ethanol inlet, and an anhydrous ethanol outlet; the dehydration tower reboiler is circularly connected to the bottom of the dehydration tower, and the dehydration tower reboiler is provided with a high-temperature gas inlet and a primary cooling liquid phase outlet; the dehydration tower top condenser is provided with a gas phase azeotrope inlet, a gas phase azeotrope condensate outlet, a cooling water inlet, and a cooling water outlet;

[0007] The primary preheating outlet of the raw material ethanol preheater is connected to the secondary preheating inlet of the raw material ethanol of the dehydration tower feed preheater, the secondary preheating outlet of the raw material ethanol of the dehydration tower feed preheater is connected to the preheated raw material ethanol inlet of the dehydration tower, the gas phase azeotrope extraction outlet of the dehydration tower is connected to the gas phase azeotrope inlet of the dehydration tower top condenser, the gas phase azeotrope condensate outlet of the dehydration tower top condenser is connected to the gas phase azeotrope condensate inlet of the oil-water separator, the oil phase extraction outlet of the oil-water separator is connected to the oil phase extraction outlet of the dehydration tower The anhydrous ethanol extraction outlet of the dehydration tower is connected with the anhydrous ethanol inlet of the dehydration tower feed preheater, the water phase extraction outlet of the oil-water separator is connected with the feed inlet of the recovery tower, the ethanol / entrainer extraction outlet of the recovery tower is connected with the high-temperature gas inlet of the dehydration tower reboiler, the primary cooling liquid phase outlet of the dehydration tower reboiler is connected with the primary cooling liquid phase inlet of the raw material ethanol preheater, the recooling liquid outlet of the raw material ethanol preheater is connected with the reflux port of the recovery tower and the secondary preheating inlet of the raw material ethanol of the dehydration tower feed preheater.

[0008] The primary preheating inlet of the raw ethanol preheater is connected to the raw ethanol input pipeline.

[0009] The anhydrous ethanol outlet of the dehydration tower feed preheater is connected to the anhydrous ethanol output pipeline.

[0010] The wastewater outlet of the recovery tower is connected to the wastewater output pipeline.

[0011] The entrainer inlet of the oil-water separator is connected to the entrainer input pipeline.

[0012] The cooling water inlet of the dehydration tower top condenser is connected to the cooling water input pipeline, and the cooling water outlet of the dehydration tower top condenser is connected to the cooling water output pipeline.

[0013] A vertical upward partition is provided at the bottom of the oil-water separator, and the oil phase production outlet and the water phase production outlet are respectively located on both sides of the partition, and the oil phase production outlet is lower than the top of the partition.

[0014] The beneficial effects of the utility model are as follows: the utility model adopts a double-tower process to obtain anhydrous ethanol through distillation, thereby reducing energy consumption, investment costs and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] In the figure: 1-dehydration tower; 2-recovery tower; 3-oil-water separator; 4-raw ethanol preheater; 5-dehydration tower feed preheater; 6-dehydration tower reboiler; 7-dehydration tower top condenser;

[0017] 11-preheating raw material ethanol inlet; 12-oil phase reflux port; 13-gas phase azeotrope extraction port; 14-anhydrous ethanol extraction port;

[0018] 21-feed port; 22-reflux port; 23-ethanol / azeotroping agent extraction port; 24-wastewater port;

[0019] 31- azeotropic agent inlet; 32- oil phase production outlet; 33- gas phase azeotropic condensate inlet; 34- water phase production outlet; 35- partition;

[0020] 41-primary preheating inlet of raw ethanol; 42-primary preheating outlet of raw ethanol; 43-primary cooling liquid phase inlet; 44-recooling liquid phase outlet;

[0021] 51-secondary preheating inlet for raw ethanol; 52-secondary preheating outlet for raw ethanol; 53-anhydrous ethanol inlet; 54-anhydrous ethanol outlet;

[0022] 61-high temperature gas inlet; 62-primary cooling liquid phase outlet;

[0023] 71-gas phase azeotrope inlet; 72-gas phase azeotrope condensate outlet; 73-cooling water inlet; 74-cooling water outlet;

[0024] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0026] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0029] An energy-saving production device for anhydrous ethanol, such as Figure 1 As shown, it includes a dehydration tower 1, a recovery tower 2, an oil-water separator 3, a raw material ethanol preheater 4, a dehydration tower feed preheater 5, a dehydration tower reboiler 6, and a dehydration tower top condenser 7.

[0030] The dehydration tower 1 and the recovery tower 2 are both distillation towers.

[0031] Distillation is the most commonly used separation method in chemical production, but some systems such as ethanol-water form azeotropes during the distillation process, and it is difficult to separate them to obtain anhydrous ethanol using ordinary distillation. In this case, special distillation such as azeotropic distillation can be used. The so-called azeotropic distillation refers to adding a third component entrainer to the original mixture to form a new azeotrope with a lower boiling point with one or more components in the original mixture. During the distillation process, the entrainer is evaporated from the top of the tower in the form of an azeotrope, and the pure substance can be obtained in the bottom of the tower.

[0032] The upper end of the side wall of the dehydration tower 1 is provided with a preheated raw material ethanol inlet 11 and an oil phase reflux port 12, a gas phase azeotrope extraction port 13 is provided at the top of the tower, and an anhydrous ethanol extraction port 14 is provided at the bottom of the tower; the upper end of the side wall of the recovery tower 2 is provided with a feed port 21 and a reflux port 22, an ethanol / entrainer extraction port 23 is provided at the top of the tower, and a wastewater port 24 is provided at the bottom of the tower; the side wall of the oil-water separator 3 is provided with an entrainer inlet 31 and an oil phase extraction port 32, a gas phase azeotrope condensate inlet 33 is provided at the top, and a water phase extraction port 34 is provided at the bottom; the raw material ethanol preheater 4 is provided with a raw material ethanol primary preheating inlet 41 , a primary preheating outlet 42 for raw ethanol, a primary cooling liquid phase inlet 43, and a secondary cooling liquid phase outlet 44; the dehydration tower feed preheater 5 is provided with a secondary preheating inlet 51 for raw ethanol, a secondary preheating outlet 52 for raw ethanol, an anhydrous ethanol inlet 53, and an anhydrous ethanol outlet 54; the dehydration tower reboiler 6 is connected to the bottom of the dehydration tower 1 in a loop, and the dehydration tower reboiler 6 is provided with a high-temperature gas inlet 61 and a primary cooling liquid phase outlet 62; the dehydration tower top condenser 7 is provided with a gas phase azeotrope inlet 71, a gas phase azeotrope condensate outlet 72, a cooling water inlet 73, and a cooling water outlet 74;

[0033] The primary preheating outlet 42 of the raw ethanol preheater 4 is connected to the secondary preheating inlet 51 of the raw ethanol of the dehydration tower feed preheater 5, the secondary preheating outlet 52 of the raw ethanol of the dehydration tower feed preheater 5 is connected to the preheated raw ethanol inlet 11 of the dehydration tower 1, the gas phase azeotrope extraction outlet 13 of the dehydration tower 1 is connected to the gas phase azeotrope inlet 71 of the dehydration tower top condenser 7, the gas phase azeotrope condensate outlet 72 of the dehydration tower top condenser 7 is connected to the gas phase azeotrope condensate inlet 33 of the oil-water separator 3, and the oil phase extraction outlet 32 ​​of the oil-water separator 3 is connected to the oil phase reflux outlet 13 of the dehydration tower 1. The anhydrous ethanol production port 12 of the dehydration tower 1 is connected with the anhydrous ethanol inlet 53 of the dehydration tower feed preheater 5, the water phase production port 34 of the oil-water separator 3 is connected with the feed port 21 of the recovery tower 2, the ethanol / entrainer production port 23 of the recovery tower 2 is connected with the high-temperature gas inlet 61 of the dehydration tower reboiler 6, the primary cooling liquid phase outlet 62 of the dehydration tower reboiler 6 is connected with the primary cooling liquid phase inlet 43 of the raw material ethanol preheater 4, and the recooling liquid outlet 44 of the raw material ethanol preheater 4 is connected with the reflux port 22 of the recovery tower 2 and the raw material ethanol secondary preheating inlet 51 of the dehydration tower feed preheater 5.

[0034] The primary preheating inlet 41 of the raw ethanol preheater 4 is connected to the raw ethanol input pipeline, and the raw ethanol contains 95% ethanol and 5% water.

[0035] The anhydrous ethanol outlet 54 of the dehydration tower feed preheater 5 is connected to the anhydrous ethanol output pipeline.

[0036] The wastewater outlet 24 of the recovery tower 2 is connected to the wastewater output pipeline.

[0037] The entrainer inlet 31 of the oil-water separator 3 is connected to the entrainer input pipeline. The entrainer is cyclohexane, benzene or a mixture thereof in any proportion.

[0038] The cooling water inlet 73 of the dehydration tower top condenser 7 is connected to the cooling water input pipeline, and the cooling water outlet 74 of the dehydration tower top condenser 7 is connected to the cooling water output pipeline.

[0039] A vertical partition 35 is provided at the bottom of the oil-water separator 3 , and the oil phase production outlet 32 ​​and the water phase production outlet 34 are respectively located on both sides of the partition 35 , and the oil phase production outlet 32 ​​is lower than the top of the partition 35 .

[0040] The raw ethanol is preheated by the raw ethanol preheater 4 and the dehydration tower feed preheater 5, and then enters the dehydration tower 1 from the preheated raw ethanol inlet 11 at the top of the dehydration tower 1. The anhydrous ethanol extraction port 14 of the dehydration tower 1 is used as the heat source of the dehydration tower feed preheater 5. The gaseous azeotrope extraction port 13 at the top of the dehydration tower 1 is used to extract the gaseous azeotrope. After being condensed by the dehydration tower top condenser 7, the gaseous azeotrope condensate is introduced into the oil-water separator 3 from the gaseous azeotrope condensate inlet 33. The azeotropic agent is extracted from the azeotropic agent. The agent inlet 31 enters the oil-water separator 3, the upper oil phase of the oil-water separator 3 is refluxed to the dehydration tower 1, the water phase extracted from the water phase extraction outlet 34 at the bottom of the oil-water separator 3 enters the tower from the feed inlet 21 at the top of the recovery tower 2, the recovery tower 2 extracts waste water, and the high-temperature gas phase extracted from the top of the recovery tower 2 is successively used as the heat source of the dehydration tower reboiler 6 and the raw material ethanol preheater 4. After the heat source is condensed, a part of it returns to the recovery tower 2, and the other part is mixed with the raw material ethanol after the first-stage preheating and enters the dehydration tower feed preheater 5.

[0041] The raw ethanol is first heat-exchanged with the liquid phase extracted from the top of the recovery tower 2 after preliminary cooling in the raw ethanol preheater 4, and then heat-exchanged with the anhydrous ethanol extracted from the bottom of the dehydration tower 1 in the dehydration tower feed preheater 5.

[0042] The gas phase condensate at the top of the dehydration tower 1 is stratified in the oil-water separator 3 , and a partition 35 is provided in the oil-water separator 3 .

[0043] The upper oil phase outlet 32 ​​of the oil-water separator 3 is connected to the oil phase reflux port 12 of the dehydration tower 1 through a pipeline, and the lower water phase outlet 34 of the oil-water separator 3 is connected to the feed port 21 of the recovery tower 2 through a pipeline.

[0044] The high-temperature gas phase extracted from the top of the recovery tower 2 is used as the heat source of the dehydration tower reboiler 6 and the raw ethanol preheater 4 in turn.

[0045] The operating pressure of the dehydration tower 1 is normal pressure, and the operating temperature is 60-85°C.

[0046] The operating pressure of recovery tower 2 is 0-5MPaG, and the operating temperature is 60-150°C.

[0047] The utility model adopts a double-tower process, namely a dehydration tower 1 and a recovery tower 2, and uses cyclohexane and benzene or a mixture of cyclohexane and benzene in any proportion as an azeotropic agent to obtain anhydrous ethanol by distillation. The utility model reduces energy consumption, investment costs and operating costs.

[0048] Anhydrous ethanol is produced from the bottom of dehydration tower 1, and waste water is produced from the bottom of recovery tower 2. Anhydrous ethanol and water are discharged from the bottoms of the two towers respectively. The separation is relatively thorough. Anhydrous ethanol can meet the qualified requirements and the concentration can reach 99.9% or higher.

[0049] The azeotropic product after the gas phase condensation at the top of the dehydration tower 1 is refluxed through the dehydration tower 1 and recovered by the recovery tower 2, so that the entrainer is recycled, the waste of the entrainer is avoided, and the equipment investment and energy are saved.

[0050] The raw ethanol and anhydrous ethanol are heat exchanged in the dehydration tower feed preheater 5, which fully utilizes the heat and saves energy.

[0051] The gas phase temperature at the top of the recovery tower 2 is relatively high, and is successively used as the heat source for the dehydration tower reboiler 6 and the raw ethanol preheater 4, which can fully improve the energy utilization rate.

[0052] The oil-water separator 3 is provided with a partition 35, which increases the separation speed of the oil phase and the water phase, enhances the separation effect, and is beneficial to the stable operation of the device.

[0053] The utility model is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the utility model, or are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. An energy-saving production device for anhydrous ethanol, characterized in that: It includes a dehydration tower (1), a recovery tower (2), an oil-water separator (3), a raw material ethanol preheater (4), a dehydration tower feed preheater (5), a dehydration tower reboiler (6), and a dehydration tower top condenser (7); The upper end of the side wall of the dehydration tower (1) is provided with a preheated raw material ethanol inlet (11) and an oil phase reflux port (12), the top of the tower is provided with a gas phase azeotrope extraction port (13), and the bottom of the tower is provided with an anhydrous ethanol extraction port (14); the upper end of the side wall of the recovery tower (2) is provided with a feed port (21) and a reflux port (22), the top of the tower is provided with an ethanol / entrainer extraction port (23), and the bottom of the tower is provided with a wastewater port (24); the side wall of the oil-water separator (3) is provided with an azeotrope inlet (31) and an oil phase extraction port (32), the top is provided with a gas phase azeotrope condensate introduction port (33), and the bottom is provided with a water phase extraction port (34); the raw material ethanol preheater (4) is provided with a raw material ethanol primary preheating inlet (41), A primary preheating outlet (42) for raw ethanol, a primary cooling liquid phase inlet (43) and a secondary cooling liquid phase outlet (44) are provided on the dehydration tower feed preheater (5); a secondary preheating inlet (51) for raw ethanol, a secondary preheating outlet (52) for raw ethanol, an anhydrous ethanol inlet (53) and an anhydrous ethanol outlet (54) are provided on the dehydration tower feed preheater (5); a dehydration tower reboiler (6) is cyclically connected to the bottom of the dehydration tower (1), and a high-temperature gas inlet (61) and a primary cooling liquid phase outlet (62) are provided on the dehydration tower reboiler (6); a gas phase azeotrope inlet (71), a gas phase azeotrope condensate outlet (72), a cooling water inlet (73) and a cooling water outlet (74) are provided on the dehydration tower top condenser (7); The primary preheating outlet (42) of the raw material ethanol preheater (4) is connected to the secondary preheating inlet (51) of the raw material ethanol of the dehydration tower feed preheater (5); the secondary preheating outlet (52) of the raw material ethanol of the dehydration tower feed preheater (5) is connected to the preheated raw material ethanol inlet (11) of the dehydration tower (1); the gas phase azeotrope extraction outlet (13) of the dehydration tower (1) is connected to the gas phase azeotrope inlet (71) of the dehydration tower top condenser (7); the gas phase azeotrope condensate outlet (72) of the dehydration tower top condenser (7) is connected to the gas phase azeotrope condensate inlet (33) of the oil-water separator (3); the oil phase extraction outlet (32) of the oil-water separator (3) is connected to the oil phase reflux outlet (121) of the dehydration tower (1); ), the anhydrous ethanol extraction port (14) of the dehydration tower (1) is connected to the anhydrous ethanol inlet (53) of the dehydration tower feed preheater (5), the water phase extraction port (34) of the oil-water separator (3) is connected to the feed port (21) of the recovery tower (2), the ethanol / entrainer extraction port (23) of the recovery tower (2) is connected to the high-temperature gas inlet (61) of the dehydration tower reboiler (6), the primary cooling liquid phase outlet (62) of the dehydration tower reboiler (6) is connected to the primary cooling liquid phase inlet (43) of the raw material ethanol preheater (4), and the secondary cooling liquid outlet (44) of the raw material ethanol preheater (4) is connected to the reflux port (22) of the recovery tower (2) and the secondary preheating inlet (51) of the raw material ethanol of the dehydration tower feed preheater (5).

2. The energy-saving production device for anhydrous ethanol according to claim 1, characterized in that: The primary preheating inlet (41) of the raw ethanol preheater (4) is connected to the raw ethanol input pipeline.

3. The energy-saving production device for anhydrous ethanol according to claim 2, characterized in that: The anhydrous ethanol outlet (54) of the dehydration tower feed preheater (5) is connected to the anhydrous ethanol output pipeline.

4. The energy-saving production device for anhydrous ethanol according to claim 3, characterized in that: The wastewater outlet (24) of the recovery tower (2) is connected to the wastewater output pipeline.

5. The energy-saving production device for anhydrous ethanol according to claim 4, characterized in that: The entrainer inlet (31) of the oil-water separator (3) is connected to the entrainer input pipeline.

6. The energy-saving production device for anhydrous ethanol according to claim 5, characterized in that: The cooling water inlet (73) of the dehydration tower top condenser (7) is connected to the cooling water input pipeline, and the cooling water outlet (74) of the dehydration tower top condenser (7) is connected to the cooling water output pipeline.

7. The energy-saving production device for anhydrous ethanol according to claim 6, characterized in that: A vertical partition (35) is provided at the bottom of the oil-water separator (3). The oil phase production port (32) and the water phase production port (34) are respectively located on both sides of the partition (35). The oil phase production port (32) is lower than the top of the partition (35).

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