CN112142562A - Method and device for reducing separation energy consumption of ethanol crude product prepared by acetic acid hydrogenation - Google Patents
Method and device for reducing separation energy consumption of ethanol crude product prepared by acetic acid hydrogenation Download PDFInfo
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Abstract
The invention relates to the field of product refining, and discloses a method and a device for reducing separation energy consumption of an ethanol crude product prepared by acetic acid hydrogenation. Preheating an ethanol crude product prepared by acetic acid hydrogenation, introducing the preheated ethanol crude product into an acetic acid separation tower, obtaining a first tower top product at the tower top, introducing the first tower top product into a crude separation tower, obtaining a second tower top product at the tower top, obtaining a second tower bottom product at the tower bottom, and introducing the second tower bottom product into an ethanol rectifying tower; (B) introducing the second tower top product into an ethylene glycol extraction tower for first extraction, obtaining a third tower top product at the tower top, and obtaining a third tower bottom product at the tower bottom; (C) introducing the bottom product of the third tower into an extractant recovery tower, obtaining a fourth tower top product at the tower top, introducing the fourth tower top product into an ethanol rectifying tower, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower; (D) and introducing the water and the third tower top product into a liquid-liquid separator for second extraction to obtain a water phase and an oil phase, and introducing the oil phase into an ethyl acetate rectifying tower. The method can reduce the energy consumption for separating the ethanol crude product prepared by acetic acid hydrogenation.
Description
Technical Field
The invention relates to the field of product refining of organic chemistry, in particular to a method and a device for reducing the separation energy consumption of an ethanol crude product prepared by acetic acid hydrogenation.
Background
Ethanol is an important commodity chemical that can be used as a motor fuel when added to gasoline. The ethanol production can adopt a fermentation method, but the cost and the energy consumption of the fermentation method are high. Therefore, a shift has been made to the coal-to-ethanol process. The coal-based ethanol mainly has three routes: (1) preparing ethanol by using synthesis gas in one step. The synthesis gas is produced by coal gasification, the synthesis gas is used for preparing low carbon alcohol by one step method, and the ethanol is separated from the mixed low carbon alcohol. (2) And (3) hydrogenation of acetic ester to prepare ethanol. Gasifying to produce synthetic gas, preparing methanol from the synthetic gas, preparing acetic acid from the methanol through carbonylation, preparing acetate through esterification of the acetic acid and ethanol, and obtaining ethanol through ester hydrogenation. (3) The acetic acid is directly hydrogenated to prepare the ethanol. Compared with the acetic ester hydrogenation route, the route for preparing the ethanol by directly hydrogenating the acetic acid has relatively simple process, and technically keys are an efficient acetic acid hydrogenation catalyst, a reactor for controlling a high exothermic reaction and product separation.
In addition, ethyl acetate is an important organic chemical raw material with wide application, has large production capacity, can be used for preparing phthalide amine, phthalide acetic acid, methyl heptenone and the like, and has wide application in the industries of spices, medicines, paint coatings, printing ink and foods. At present, the main production method in China is to react acetic acid with ethanol under the catalysis of concentrated sulfuric acid, and then the acetic acid is obtained through deacidification, dehydration and refining.
In the production of ethanol and ethyl acetate, the crude products contain acetic acid, ethanol, ethyl acetate and other main components, in addition, the byproducts are also complex, although the content of the byproducts is not large, the formation of various azeotropes brings certain difficulty to separation, and the energy consumption of simple azeotropic distillation is high, and the separation is also difficult.
Extractive distillation is a common method, but the energy consumption of different extracting agents is different during extractive distillation.
CN103265402A discloses a method for reducing energy consumption in a process of preparing ethanol by acetate hydrogenation. The binary azeotropic mixture generated by unreacted acetic ester and alcohol in the acetic ester hydrogenation reaction liquid is not subjected to subsequent rectification separation, but directly returned to a hydrogenation section for catalyst hydrogenation treatment, so that the acetic ester in the azeotrope is continuously subjected to catalytic hydrogenation to generate the ethanol. Although this method temporarily reduces the energy consumption for separation, the extent of the rehydrogenation reaction that can be achieved varies from catalyst to catalyst for different reaction processes, and the reaction still needs to be separated as the concentration of reactants decreases.
CN102399130A discloses a method for simplifying the rectification process of preparing ethanol by acetic acid hydrogenation, which comprises the following steps: 1) adding raw materials of ethanol and acetic acid from the tower kettle of the esterification tower, and reacting under the catalysis of sulfuric acid circulating in the tower kettle; 2) reacting and separating through an esterification tower to obtain a crude product of the hydrogenation raw material ethyl acetate for the reaction of a hydrogenation process, and recovering ester and alcohol in water generated by the esterification reaction through a wastewater recovery tower to return to the esterification tower for a new reaction; 3) carrying out hydrogenation reaction on the ethyl acetate crude product obtained in the step 2) through a catalyst, cooling the material at the outlet of a hydrogenation reactor, recycling the hydrogen and a small amount of organic components which are subjected to gas-liquid separation and are subjected to reaction to the inlet of the hydrogenation reactor for reuse, feeding the liquid-phase material from the middle part of a concentration tower in the ethyl acetate production flow, extracting unreacted ethyl acetate and a small amount of ethanol from the top of the tower after the liquid-phase material is subjected to extraction, rectification and separation through ethylene glycol, feeding the material at the bottom of the tower into a low ester recovery tower in the ethyl acetate production flow, removing water in the material through an ethylene glycol extraction and rectification method, and finally obtaining an anhydrous ethanol product at the top of the tower; 4) and 3) rectifying and separating the tower bottom material in the step 3) by a refining tower in the ethyl acetate production flow, and returning the ethylene glycol obtained from the tower bottom to the concentration tower and the low ester recovery tower for recycling. Although the absolute ethanol product is obtained in the step 3), the energy consumption of the method is large.
Therefore, aiming at the process for preparing ethanol by hydrogenating acetic acid, the obtained ethanol crude product has complex composition and has the problem of large separation energy consumption during separation.
Disclosure of Invention
The invention aims to solve the problem of large energy consumption for separating an ethanol crude product prepared by acetic acid hydrogenation in the prior art, and provides a method and a device for reducing the energy consumption for separating the ethanol crude product prepared by acetic acid hydrogenation.
In order to achieve the above object, the first aspect of the present invention provides a method for reducing energy consumption for separating ethanol crude product obtained by acetic acid hydrogenation, comprising:
(A) preheating an ethanol crude product obtained by acetic acid hydrogenation, introducing the ethanol crude product into an acetic acid separation tower, obtaining a first tower top product containing ethanol, ethyl acetate and water at the tower top, introducing the first tower top product into a crude separation tower, obtaining a second tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a second tower bottom product containing ethanol and water at the tower bottom; introducing the second tower bottom product into an ethanol rectifying tower;
(B) introducing ethylene glycol and the second tower top product into an ethylene glycol extraction tower for first extraction, obtaining a third tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a third tower bottom product containing ethylene glycol and ethanol at the tower bottom;
(C) introducing the third tower bottom product into an extractant recovery tower, and obtaining a fourth tower top product containing ethanol and water at the tower top; introducing the fourth tower top product into an ethanol rectifying tower, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower;
(D) and introducing water and the third tower top product into a liquid-liquid separator for second extraction to obtain a water phase and an oil phase, introducing the oil phase into an ethyl acetate rectifying tower, obtaining a product containing ethyl acetate at the tower bottom, and obtaining a light component at the tower top.
The invention provides a device for reducing the energy consumption of separation of ethanol crude products prepared by acetic acid hydrogenation, wherein the device comprises: an acetic acid separation tower, a crude separation tower, an ethylene glycol extraction tower, an extractant recovery tower, an ethanol rectifying tower, a liquid-liquid separator and an ethyl acetate rectifying tower, wherein,
the acetic acid separation tower is used for separating an ethanol crude product prepared by acetic acid hydrogenation, a first tower top product containing ethanol, ethyl acetate and water is obtained at the tower top, and the first tower top product is introduced into the crude separation tower;
the rough separation tower is used for separating the first tower top product, a second tower top product containing ethyl acetate, water and ethanol is obtained at the tower top, and a second tower bottom product containing ethanol and water is obtained at the tower bottom; introducing the second tower bottom product into an ethanol rectifying tower;
the ethylene glycol extraction tower is used for carrying out first extraction on the second tower top product through ethylene glycol, a third tower top product containing ethyl acetate, water and ethanol is obtained at the tower top, and a third tower bottom product containing ethylene glycol and ethanol is obtained at the tower bottom;
the extractant recovery tower is used for separating the third bottom product to obtain a fourth top product containing ethanol and water at the top of the tower;
the ethanol rectifying tower is used for carrying out ethanol separation on the second tower bottom product and the fourth tower top product to obtain a product containing ethanol;
the liquid-liquid separator is used for carrying out second extraction on the third tower top product through water to obtain a water phase and an oil phase;
and the ethyl acetate rectifying tower is used for separating the oil phase, obtaining a product containing ethyl acetate at the bottom of the tower and obtaining a light component at the top of the tower.
The method can reduce the using amount of the glycol extractant used in the glycol extraction tower by arranging the acetic acid separation tower, the crude separation tower and the extractant recovery tower, and a third tower top product containing ethyl acetate, water and ethanol, which is obtained from the tower top of the glycol extraction tower, is introduced into the liquid-liquid separator to be extracted with at least part of water at the tower bottom of the ethanol crude distillation tower, and residual ethanol is extracted by adopting a standing and layering mode, so that the using amount of water is reduced. The ethylene glycol extractant and the water extractant can respectively come from the extractant recovery tower and the ethanol rectification tower, so that the recycling is realized, and the effects of energy conservation and emission reduction are achieved. In addition, at least part of water at the bottom of the ethanol crude distillation tower exchanges heat with the heater, so that the heat supply of the heater is reduced, and part of energy consumption is reduced. The total load of the top and the bottom of the acetic acid separation tower, the crude separation tower, the glycol extraction tower, the extractant recovery tower, the ethanol rectification tower and the ethyl acetate rectification tower is calculated (the load heat of a heater is from the bottom material flow of the ethanol rectification tower, belongs to the comprehensive utilization of internal heat and can not be considered; the load of a cooler is smaller and can be ignored), and the heat load is obviously reduced, so that the method can effectively reduce the separation energy consumption of the ethanol crude product prepared by acetic acid hydrogenation.
Drawings
FIG. 1 is a schematic process flow diagram of the separation system for the crude ethanol product from acetic acid hydrogenation according to the present invention.
Description of the reference numerals
1. Acetic acid separation tower 2, rough separation tower
3. Ethylene glycol extraction tower 4 and extractant recovery tower
5. Ethanol rectifying tower 6 and liquid-liquid separator
7. Ethyl acetate rectifying tower 8, heater
9. Cooling device
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
In the present invention, the use of directional terms such as "top, bottom, side" and "lateral" generally refer to the top, bottom and side as illustrated in the accompanying drawings.
In the present invention, the terms "first", "second", "third" and "fourth" are used for distinguishing different devices and/or components without limiting the specific contents of the devices and/or components.
The invention provides a method for reducing the energy consumption of separation of an ethanol crude product prepared by acetic acid hydrogenation, wherein the process flow diagram is shown in figure 1, and the method comprises the following steps:
(A) preheating an ethanol crude product obtained by acetic acid hydrogenation, introducing the ethanol crude product into an acetic acid separation tower 1, obtaining a first tower top product containing ethanol, ethyl acetate and water at the tower top, introducing the first tower top product into a crude separation tower 2, obtaining a second tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a second tower bottom product containing ethanol and water at the tower bottom; introducing the second tower bottom product into an ethanol rectifying tower 5;
(B) introducing ethylene glycol and the second tower top product into an ethylene glycol extraction tower 3 for first extraction, obtaining a third tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a third tower bottom product containing ethylene glycol and ethanol at the tower bottom;
(C) introducing the third bottom product into an extractant recovery tower 4 to obtain a fourth top product containing ethanol and water at the top of the tower; introducing the fourth tower top product into an ethanol rectifying tower 5, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower 5;
(D) and introducing the water and the third tower top product into a liquid-liquid separator 6 for second extraction to obtain a water phase and an oil phase, introducing the oil phase into an ethyl acetate rectifying tower 7, obtaining a product containing ethyl acetate at the tower bottom, and obtaining a light component at the tower top.
According to the method, based on the total weight of the ethanol crude product obtained by hydrogenating acetic acid, the content of ethanol may be 45 to 70 wt%, the content of ethyl acetate may be 1 to 20 wt%, the content of acetic acid may be 5 to 20 wt%, the content of water may be 10 to 35 wt%, and the content of byproducts may be 0 to 10 wt%, wherein the byproducts may include but are not limited to: acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol, carbon monoxide hexanoate and carbon dioxide.
According to the method, the ethanol crude product obtained by acetic acid hydrogenation refers to the crude product obtained by the process of preparing ethanol by acetic acid hydrogenation.
According to the method, the first extraction is carried out in the ethylene glycol extraction tower 3 through ethylene glycol, and the weight ratio of the ethylene glycol to the second tower top product calculated by ethanol can be (0.2-0.3): 1, operating an initial stage, and introducing an additional glycol extractant; the ethylene glycol can be added ethylene glycol extractant and can also be a fourth bottom product obtained at the bottom of the extractant recovery tower 4 along with the operation of the device, and the fourth bottom product obtained at the bottom of the extractant recovery tower 4 is preferred in order to reduce the consumption of raw materials and the discharge of waste products.
According to the method of the invention, the second extraction is carried out in the liquid-liquid separator 6 by a water extraction agent, and the weight ratio of water to the third overhead product calculated by ethyl acetate can be (0.2-0.4): the water used may be fresh water or recycled water used in the method provided by the invention, such as the product at the bottom of the ethanol rectification tower 5, and at least part of the water obtained at the bottom of the ethanol rectification tower 5 is preferred in order to reduce the consumption of raw materials and the discharge of waste products.
In a preferred case, to reduce energy consumption, the method further comprises: and carrying out gas-liquid separation on an ethanol crude product prepared by acetic acid hydrogenation to obtain liquid-phase crude ethanol, and preheating the liquid-phase crude ethanol. After preheating, the mixture is introduced into an acetic acid separation tower 1.
In a preferred case, in order to reduce energy consumption and achieve full utilization of resources, the method further comprises: and introducing a fourth bottom product containing ethylene glycol obtained from the bottom of the extractant recovery tower 4 into the ethylene glycol extraction tower 3 for recycling.
In a preferred case, in order to reduce energy consumption and achieve full utilization of resources, the method further comprises: cooling at least part of water obtained at the bottom of the ethanol rectifying tower 5, and introducing the cooled water into a liquid-liquid separator 6, wherein the cooling temperature is preferably 20-40 ℃. The amount of water introduced is such as to satisfy the weight ratio of water to the third overhead product in terms of ethyl acetate, with the aim of maximizing the second extraction.
In a preferred case, in order to reduce energy consumption and achieve full utilization of resources, the method further comprises: the aqueous phase is passed to a crude separation column 2.
According to the method of the present invention, preferably, the operating conditions of the acetic acid separation column 1 include: the temperature at the top of the tower is 70-100 ℃, and preferably 79-89 ℃; the temperature of the tower bottom is 105-140 ℃, and preferably 119-129 ℃; the pressure at the top of the tower is 0.03-0.2 MPa, preferably 0.08-0.12 MPa; the pressure at the bottom of the tower is 0.09-0.3 MPa, preferably 0.13-0.17 MPa; the number of the tower plates is 10-40, and preferably 20-30; the reflux ratio is 2 to 7, preferably 2.5 to 5. The product containing unreacted acetic acid is obtained at the bottom of the acetic acid separation tower.
According to the method, the operation conditions of the rough separation tower 2 can include that the tower top temperature is 40-75 ℃, preferably 58-70 ℃; the temperature of the tower bottom is 76-100 ℃, and preferably 80-89 ℃; the pressure at the top of the tower is 0.02-0.12 MPa, preferably 0.06-0.1 MPa; the pressure at the bottom of the tower is 0.08-0.2 MPa, preferably 0.1-0.14 MPa; the number of the tower plates is 10-40, and preferably 20-30; the reflux ratio is 2 to 8, preferably 3 to 6. In the rough separation tower 2, ethanol and water with high content are separated, so that the using amount of the glycol extractant is reduced, the concentration of the recovered glycol is further reduced, and partial energy consumption is reduced.
According to the method of the present invention, preferably, the operating conditions of the ethylene glycol extraction column 3 may include: the temperature at the top of the tower is 20-60 ℃, and the preferable temperature is 28-49 ℃; the temperature of the tower bottom is 60-90 ℃, and preferably 63-76 ℃; the pressure at the top of the tower is 0.01-0.1 MPa, preferably 0.02-0.05 MPa; the pressure at the bottom of the tower is 0.02-0.1 MPa, preferably 0.04-0.07 MPa; the number of the tower plates is 30-80, preferably 50-63; the reflux ratio is 2 to 15, preferably 5 to 12. In the ethylene glycol extraction tower 3, the first extraction is carried out by contacting ethylene glycol with a first tower top product, and a product mainly comprising ethylene glycol and ethanol is obtained at the bottom of the tower.
According to the method of the present invention, preferably, the operating conditions of the extractant recovery column 4 may include: the temperature at the top of the tower is 60-100 ℃, and preferably 74-86 ℃; the temperature of the tower bottom is 160-240 ℃, and 193-206 ℃ is preferred; the pressure at the top of the tower is 0.02-0.15 MPa, preferably 0.06-0.1 MPa; the pressure at the bottom of the tower is 0.05-0.2 MPa, preferably 0.09-0.13 MPa; the number of the tower plates is 8-30, and preferably 12-20; the reflux ratio is 1 to 10, preferably 2 to 5. In the extractant recovery tower 4, ethanol and glycol are separated, a product mainly containing ethanol is obtained at the tower top, a product mainly containing glycol is obtained at the tower bottom and is used for recycling of the glycol extraction tower 3, and after the tower runs stably, the glycol can be recycled without supplementing additional fresh glycol, so that energy is saved, emission is reduced, and energy consumption is reduced.
According to the method of the present invention, preferably, the operating conditions of the ethanol rectification column 5 may include: the temperature at the top of the tower is 60-85 ℃, and preferably 73-80 ℃; the temperature of the tower bottom is 90-120 ℃, and preferably 94-103 ℃; the pressure at the top of the tower is 0.05-0.15 MPa, preferably 0.08-0.11 MPa; the pressure at the bottom of the tower is 0.08-0.2 MPa, preferably 0.1-0.14 MPa; the number of the tower plates is 20-50, preferably 33-40; the reflux ratio is 2 to 10, preferably 4 to 8. The ethanol rectifying tower 5 obtains a product with high purity and recovery rate and mainly comprising ethanol at the top, and obtains a product with mainly comprising water at the bottom, wherein part of water can be discharged out of the device, and the part of water is supplied to the liquid-liquid separator 6 for use as required, so that the discharge of waste water is reduced.
According to the method of the present invention, preferably, the operating conditions of the ethyl acetate rectification column 7 may include: the temperature at the top of the tower is 15-50 ℃, and the preferable temperature is 23-35 ℃; the temperature of the tower bottom is 60-90 ℃, and preferably 64-76 ℃; the pressure at the top of the tower is 0.05-0.15 MPa, preferably 0.06-0.09 MPa; the pressure at the bottom of the tower is 0.05-0.2 MPa, preferably 0.08-0.12 MPa; the number of the tower plates is 10-30, preferably 14-22; the reflux ratio is 2 to 10, preferably 3 to 9. The light component product mainly containing acetaldehyde is obtained at the top of the ethyl acetate rectifying tower 7, and the product mainly containing ethyl acetate is obtained at the bottom of the ethyl acetate rectifying tower.
According to the method of the present invention, preferably, the temperature of the preheating in the step (a) may be 30 to 50 ℃, preferably 40 to 45 ℃.
According to an embodiment of the invention, the method may comprise the steps of:
(A) carrying out gas-liquid separation on an ethanol crude product obtained by hydrogenating acetic acid to obtain liquid-phase crude ethanol, preheating the crude ethanol to 30-50 ℃, preferably 40-45 ℃, introducing the crude ethanol into an acetic acid separation tower 1, obtaining a first tower top product containing ethanol, ethyl acetate, water and byproducts from the tower top, and obtaining a product containing acetic acid and water from the tower bottom;
(B) introducing the first tower top product into a rough separation tower 2, obtaining a second tower top product containing ethyl acetate, water, ethanol and byproducts at the tower top, and obtaining a second tower bottom product containing water at the tower bottom; introducing the second tower bottom product into an ethanol rectifying tower 5;
(C) introducing the second tower top product into an ethylene glycol extraction tower 3, and extracting by using an ethylene glycol solvent to obtain a third tower top product containing ethyl acetate, water, ethanol and byproducts at the tower top and obtain a third tower bottom product containing ethylene glycol, ethanol, ethyl acetate and water at the tower bottom;
(D) pumping the third tower bottom product into an extractant recovery tower 4, obtaining a fourth tower top product containing ethanol and water at the tower top, obtaining a fourth tower bottom product containing glycol at the tower bottom, introducing the fourth tower bottom product into an ethylene glycol extraction tower 3, and completely circulating the fourth tower bottom product at the tower bottom of the extractant recovery tower 4 after the ethylene glycol extraction tower 3 operates stably without additionally adding supplemental ethylene glycol; introducing the fourth tower top product into an ethanol rectifying tower 5, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower 5;
(E) introducing the third tower top product into a liquid-liquid separator 6, cooling water obtained at the tower bottom of an ethanol rectifying tower 5 to 15-25 ℃, introducing the water into the liquid-liquid separator 6 from the top, standing and separating to obtain a water phase and an oil phase, introducing the water phase into a crude separation tower 2, introducing the oil phase into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the tower bottom; light components containing byproducts are obtained at the top of the tower.
In a second aspect, the present invention provides an apparatus for reducing energy consumption for separating ethanol crude product from acetic acid hydrogenation, as shown in fig. 1, the apparatus comprising: an acetic acid separation tower 1, a crude separation tower 2, an ethylene glycol extraction tower 3, an extractant recovery tower 4, an ethanol rectification tower 5, a liquid-liquid separator 6 and an ethyl acetate rectification tower 7, wherein,
the acetic acid separation tower 1 is used for separating an ethanol crude product obtained by acetic acid hydrogenation, a first tower top product containing ethanol, ethyl acetate and water is obtained at the tower top, and the first tower top product is introduced into the crude separation tower 2;
the rough separation tower 2 is used for separating the first tower top product, a second tower top product containing ethyl acetate, water and ethanol is obtained at the tower top, and a second tower bottom product containing ethanol and water is obtained at the tower bottom; introducing the second tower bottom product into an ethanol rectifying tower 5;
the ethylene glycol extraction tower 3 is used for carrying out first extraction on the second tower top product through ethylene glycol to obtain a third tower top product containing ethyl acetate, water and ethanol at the tower top and obtain a third tower bottom product containing ethylene glycol and ethanol at the tower bottom;
the extractant recovery tower 4 is used for separating the third bottom product to obtain a fourth top product containing ethanol and water at the top of the tower;
the ethanol rectifying tower 5 is used for carrying out ethanol separation on the second tower bottom product and the fourth tower top product to obtain a product containing ethanol;
the liquid-liquid separator 6 is used for carrying out second extraction on the third tower top product through water to obtain a water phase and an oil phase;
and the ethyl acetate rectifying tower 7 is used for separating the oil phase, obtaining a product containing ethyl acetate at the bottom of the tower, and obtaining a light component at the top of the tower.
In a preferable case, the device further comprises a gas-liquid separator for performing gas-liquid separation on the ethanol crude product obtained by the hydrogenation of the acetic acid to obtain liquid-phase crude ethanol. Preferably, the tower bottom outlet of the gas-liquid separator is communicated with the inlet of the acetic acid separation tower 1, and the tower bottom outlet of the acetic acid separation tower 1 is communicated with the inlet of the crude separation tower 2; preferably, the device also comprises a heater 8 for heating the liquid phase crude ethanol and then introducing the liquid phase crude ethanol into the acetic acid separation tower 1.
According to a preferred embodiment of the invention, the outlet at the bottom of the rough separation tower 2 is communicated with the inlet of the ethanol rectifying tower 5, and the outlet at the top of the tower is communicated with the inlet of the glycol extraction tower 3; an outlet at the top of the glycol extraction tower 3 is communicated with an inlet of a liquid-liquid separator 6, and an outlet at the bottom of the glycol extraction tower is communicated with an inlet of an extractant recovery tower 4; the outlet of the top of the extractant recovery tower 4 is communicated with the inlet of the ethanol rectifying tower 5, and the outlet of the bottom of the extractant recovery tower is communicated with the inlet of the glycol extraction tower 3; the outlet at the bottom of the ethanol rectifying tower 5 is communicated with the inlet of the liquid-liquid separator 6; the water phase outlet of the liquid-liquid separator 6 is communicated with the inlet of the crude separation tower 2, and the oil phase outlet is communicated with the inlet of the ethyl acetate rectifying tower 7.
Preferably, the device further comprises a cooler 9 for cooling at least part of water obtained at the bottom of the ethanol rectification tower 5 and then introducing the cooled water into the liquid-liquid separator 6, preferably from the top of the liquid-liquid separator 6.
The present invention will be described in detail below by way of examples.
The products at the top and bottom of the column were measured by gas chromatography (from Agilent, model GC-7890B);
ethanol recovery% — weight of ethanol in product/weight of ethanol in feed x 100%;
ethyl acetate recovery% (% ethyl acetate recovery) (% ethyl acetate weight in product/weight of ethyl acetate in feed x 100%);
the total load is the total load of the condenser plus the total load of the reboiler.
The crude ethanol products obtained by acetic acid hydrogenation used in the following examples and comparative examples were obtained from a 30-ten-thousand-ton/year acetic acid hydrogenation ethanol production plant, and specifically, the crude ethanol products obtained by acetic acid hydrogenation had the composition of the raw material shown in Table 1-1, wherein the specific composition of the by-product impurities in Table 1-1 is shown in Table 1-2.
TABLE 1-1
| Composition of | Acetic acid | Ethanol | Ethyl acetate | Water (W) | By-product impurities |
| Content by weight% | 7.55 | 58.37 | 6.48 | 26.63 | 0.97 |
Tables 1 to 2
| Composition of | Acetaldehyde | Formic acid | Positive propyleneAlcohol(s) | Acetone (II) | Ethane (III) | Carbon monoxide |
| Content by weight% | 0.69 | 0.07 | 0.07 | 0.033 | 0.0003 | 0.001 |
| Composition of | Carbon dioxide | Methanol | Propionic acid | Butyric acid | 1-Butanol | Isopropanol (I-propanol) |
| Content by weight% | 0.018 | 0.010 | 0.020 | 0.010 | 0.005 | 0.010 |
| Composition of | Valeric acid | 2-pentanone | Ether (A) | 2-Butanol | Hexanoic acid | Others |
| Content by weight% | 0.005 | 0.010 | 0.005 | 0.005 | 0.005 | 0.0027 |
Example 1
(A) As shown in fig. 1, the ethanol crude product obtained by hydrogenating acetic acid shown in tables 1 and 2 was subjected to gas-liquid separation to obtain liquid-phase crude ethanol, which was preheated to 42 ℃, and introduced into an acetic acid separation column 1 to obtain a first overhead product containing 63 wt% of ethanol, 7 wt% of ethyl acetate, 28 wt% of water and 2 wt% of by-products at the top of the column and a product containing 92 wt% of acetic acid, 6.6 wt% of water and 1.4 wt% of by-products at the bottom of the column; introducing the first overhead product into a crude separation tower 2, wherein a second overhead product containing 52.8 wt% of ethyl acetate, 4.5 wt% of water, 36.6 wt% of ethanol and 6.1 wt% of byproducts is obtained at the top of the tower, and a second bottom product containing 67.5 wt% of ethanol, 32 wt% of water and 0.5 wt% of byproducts is obtained at the bottom of the tower; introducing the second tower bottom product into an ethanol rectifying tower 5;
(B) introducing the second overhead product into an ethylene glycol extraction tower 3, and extracting the second overhead product by using 710kg/h of an added ethylene glycol solvent to obtain a third overhead product containing 78.1 wt% of ethyl acetate, 6.8 wt% of water, 3.7 wt% of ethanol and 11.4 wt% of byproducts at the tower top and a third bottom product containing 32.6 wt% of ethylene glycol, 44.4 wt% of ethanol and 23.0 wt% of water at the tower bottom;
(C) pumping the third bottom product into an extractant recovery tower 4, obtaining a fourth top product containing 65.9 wt% of ethanol and 34.1 wt% of water at the top of the tower, obtaining a fourth bottom product containing ethylene glycol at the bottom of the tower, introducing the fourth bottom product into an ethylene glycol extraction tower 3, and completely circulating the fourth bottom product at the bottom of the extractant recovery tower 4 after the ethylene glycol extraction tower 3 operates stably without adding supplemental ethylene glycol; introducing the fourth tower top product into an ethanol rectifying tower 5, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower 5, wherein the ethanol content is 92.4 wt%, the water content is 7.6 wt%, and the recovery rate of the ethanol is 96.8%;
(D) introducing the third tower top product into a liquid-liquid separator 6, cooling part of 1300kg/h water obtained at the tower bottom of an ethanol rectifying tower 5 to 25 ℃, introducing the water into the liquid-liquid separator 6 from the top, standing and separating to obtain a water phase and an oil phase, introducing the water phase into a crude separation tower 2, introducing the oil phase into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the tower bottom, wherein the ethyl acetate content is 91.5 wt%, the water content is 5.3%, the ethanol content is 2.8%, and the recovery rate of the ethyl acetate is 98.1%; light components containing byproducts mainly comprising acetaldehyde are obtained at the tower top;
wherein, in the steps (A) to (D), the byproduct is one or more of acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, carbon monoxide, carbon dioxide, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol and hexanoic acid;
wherein, the operation conditions of the acetic acid separation tower, the crude separation tower, the glycol extraction tower, the extractant recovery tower, the ethanol rectification tower and the ethyl acetate rectification tower are shown in table 2.
Table 2.
The total load of the top coolers of the acetic acid separation column, the crude separation column, the ethylene glycol extraction column, the extractant recovery column, the ethanol rectification column and the ethyl acetate rectification column, and the total load of the reboiler at the bottom of the column were calculated, and the results are shown in table 7.
Example 2
(A) As shown in fig. 1, the ethanol crude product obtained by hydrogenating acetic acid shown in table 1 and table 2 was subjected to gas-liquid separation to obtain liquid-phase crude ethanol, the crude ethanol was preheated to 40 ℃ and introduced into an acetic acid separation column 1, a first overhead product containing 63.4 wt% of ethanol, 7 wt% of ethyl acetate, 28.4 wt% of water, and 1.2 wt% of by-products was obtained at the top of the column, and a product containing 92.6 wt% of acetic acid, 5.8 wt% of water, and 1.6 wt% of by-products was obtained at the bottom of the column; introducing the first overhead product into a crude separation column 2, wherein a second overhead product containing 52.7 wt% of ethyl acetate, 4.4 wt% of water, 36.8 wt% of ethanol and 6.1 wt% of byproducts is obtained at the top of the column, and a second bottom product containing 67.4 wt% of ethanol, 32.1 wt% of water and 0.5 wt% of byproducts is obtained at the bottom of the column; introducing the second tower bottom product into an ethanol rectifying tower 5;
(B) introducing the second overhead product into an ethylene glycol extraction tower 3, and extracting by adding an ethylene glycol solvent at a rate of 80kg/h to obtain a third overhead product containing 76.4 wt% of ethyl acetate, 5 wt% of water, 7.4 wt% of ethanol and 11.2 wt% of byproducts at the tower top and a third bottom product containing 32.9 wt% of ethylene glycol, 42.9 wt% of ethanol, 1.5 wt% of ethyl acetate, 22.6 wt% of water and 0.1 wt% of byproducts at the tower bottom;
(C) pumping the third tower bottom product into an extractant recovery tower 4, obtaining a fourth tower top product containing 64 wt% of ethanol and 33.7 wt% of water at the tower top, obtaining a fourth tower bottom product containing glycol at the tower bottom, introducing the fourth tower bottom product into an ethylene glycol extraction tower 3, and completely circulating the fourth tower bottom product at the tower bottom of the extractant recovery tower 4 after the ethylene glycol extraction tower 3 operates stably without additionally adding supplemental glycol; introducing the fourth tower top product into an ethanol rectifying tower 5, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower 5, wherein the ethanol content is 92.6 wt%, the water content is 7 wt%, the byproduct content is 0.4 wt%, and the recovery rate of the ethanol is 96.15%;
(D) introducing the third tower top product into a liquid-liquid separator 6, cooling 1300kg/h of water obtained at the tower bottom of an ethanol rectifying tower 5 to 20 ℃, introducing the water into the liquid-liquid separator 6 from the top, standing and separating to obtain a water phase and an oil phase, introducing the water phase into a crude separation tower 2, introducing the oil phase into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the tower bottom, wherein the ethyl acetate content is 88 wt%, the water content is 5.9 wt%, the ethanol content is 5.9 wt%, and the ethyl acetate recovery rate is 93.6%; light components containing byproducts mainly comprising acetaldehyde are obtained at the tower top;
wherein, in the steps (A) to (D), the byproduct is one or more of acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, carbon monoxide, carbon dioxide, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol and hexanoic acid;
wherein, the operation conditions of the acetic acid separation tower, the crude separation tower, the glycol extraction tower, the extractant recovery tower, the ethanol rectification tower and the ethyl acetate rectification tower are shown in table 3.
Table 3.
The total load of the top coolers of the acetic acid separation column, the crude separation column, the ethylene glycol extraction column, the extractant recovery column, the ethanol rectification column and the ethyl acetate rectification column, and the total load of the reboiler at the bottom of the column were calculated, and the results are shown in table 7.
Example 3
(A) As shown in fig. 1, the ethanol crude product obtained by hydrogenating acetic acid shown in table 1 and table 2 was subjected to gas-liquid separation to obtain liquid-phase crude ethanol, the crude ethanol was preheated to 45 ℃ and introduced into an acetic acid separation column 1, a first overhead product containing 63.3 wt% of ethanol, 7 wt% of ethyl acetate, 28.5 wt% of water, and 1.2 wt% of by-products was obtained at the top of the column, and a product containing 93.5 wt% of acetic acid, 4.5 wt% of water, and 2 wt% of by-products was obtained at the bottom of the column; introducing the first overhead product into a crude separation column 2, wherein a second overhead product containing 52.8 wt% of ethyl acetate, 4.2 wt% of water, 36.9 wt% of ethanol and 6.1 wt% of byproducts is obtained at the top of the column, and a second bottom product containing 67.4 wt% of ethanol, 32.3 wt% of water and 0.3 wt% of byproducts is obtained at the bottom of the column; introducing the second tower bottom product into an ethanol rectifying tower 5;
(B) introducing the second overhead product into an ethylene glycol extraction tower 3, and extracting by adding an ethylene glycol solvent at a rate of 80kg/h to obtain a third overhead product containing 76.1 wt% of ethyl acetate, 7.5 wt% of water, 4.8 wt% of ethanol and 11.6 wt% of byproducts at the tower top and a third bottom product containing 32.2 wt% of ethylene glycol, 43.7 wt% of ethanol, 1.9 wt% of ethyl acetate, 22.1 wt% of water and 0.1 wt% of byproducts at the tower bottom;
(C) pumping the third bottom product into an extractant recovery tower 4, obtaining a fourth top product containing 64.5 weight percent of ethanol and 32.7 weight percent of water at the top of the tower, obtaining a fourth bottom product containing ethylene glycol at the bottom of the tower, introducing the fourth bottom product into an ethylene glycol extraction tower 3, and completely circulating the fourth bottom product at the bottom of the extractant recovery tower 4 after the ethylene glycol extraction tower 3 operates stably without adding supplemental ethylene glycol; introducing the fourth tower top product into an ethanol rectifying tower 5, and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower 5, wherein the ethanol content is 92.2 wt%, the water content is 7.5 wt%, the byproduct content is 0.3 wt%, and the recovery rate of the ethanol is 95.7%;
(D) introducing the third tower top product into a liquid-liquid separator 6, cooling 1300kg/h of water obtained at the tower bottom of an ethanol rectifying tower 5 to 20 ℃, introducing the water into the liquid-liquid separator 6 from the top, standing and separating to obtain a water phase and an oil phase, introducing the water phase into a crude separation tower 2, introducing the oil phase into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the tower bottom, wherein the content of the ethyl acetate is 90.7 wt%, the water content is 5.5 wt%, and the recovery rate of the ethyl acetate is 95.5%; light components containing byproducts mainly comprising acetaldehyde are obtained at the tower top;
wherein, in the steps (A) to (D), the byproduct is one or more of acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, carbon monoxide, carbon dioxide, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol and hexanoic acid;
wherein, the operation conditions of the acetic acid separation tower, the crude separation tower, the glycol extraction tower, the extractant recovery tower, the ethanol rectification tower and the ethyl acetate rectification tower are shown in table 4.
Table 4.
The total load of the top coolers of the acetic acid separation column, the crude separation column, the ethylene glycol extraction column, the extractant recovery column, the ethanol rectification column and the ethyl acetate rectification column, and the total load of the reboiler at the bottom of the column were calculated, and the results are shown in table 7.
Comparative example 1
(A) Carrying out gas-liquid separation on ethanol crude products obtained by hydrogenating acetic acid shown in tables 1 and 2 to obtain liquid-phase crude ethanol, introducing the crude ethanol into an acetic acid separation tower 1, obtaining a first tower top product containing 63 wt% of ethanol, 7 wt% of ethyl acetate, 28 wt% of water and 2 wt% of byproducts at the tower top, and obtaining a product containing 92 wt% of acetic acid, 6.6 wt% of water and 1.4 wt% of byproducts at the tower bottom;
(B) introducing the first overhead product into an ethylene glycol extraction tower 3, and extracting by adding an ethylene glycol solvent at a rate of 80kg/h to obtain a third overhead product containing 79.8 wt% of ethyl acetate, 3.5 wt% of water, 7.1 wt% of ethanol and 9.6 wt% of byproducts at the tower top and obtain an ethylene glycol extraction tower bottom product containing 16.4 wt% of ethylene glycol, 57.4 wt% of ethanol, 0.2 wt% of ethyl acetate and 25.6 wt% of water at the tower bottom;
(C) pumping the ethylene glycol tower bottom product into an ethanol rectifying tower 5 to obtain a fourth tower top product containing 94.4 wt% of ethanol and 5.1 wt% of water at the tower top, wherein the recovery rate of the ethanol is 96.8%; and a fourth tower bottom product containing glycol is obtained at the tower bottom and is introduced into an extracting agent recovery tower 4, a product containing glycol is obtained at the tower bottom of the extracting agent recovery tower, and the glycol can be recycled after being completely recovered.
(D) Introducing the ethylene glycol extraction tower top product into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the tower bottom, wherein the purity of the ethyl acetate is 91.3 wt%, the ethanol content is 6.1 wt%, and the recovery rate of the ethyl acetate is 71.8%; light components containing byproducts are obtained at the tower top;
wherein, in the steps (A) to (D), the byproduct is one or more of acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, carbon monoxide, carbon dioxide, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol and hexanoic acid;
wherein, the operation conditions of the acetic acid separation column, the ethylene glycol extraction column, the extractant recovery column, the ethanol rectification column and the ethyl acetate rectification column are shown in table 5.
Table 5.
The total load of the top coolers of the acetic acid separation column, the ethylene glycol extraction column, the extractant recovery column, the ethanol rectification column and the ethyl acetate rectification column, and the total load of the reboiler at the bottom of the column were calculated, and the results are shown in table 7.
Comparative example 2
(A) Carrying out gas-liquid separation on ethanol crude products obtained by hydrogenating acetic acid shown in tables 1 and 2 to obtain liquid-phase crude ethanol, introducing the crude ethanol into an acetic acid separation tower 1, obtaining a first tower top product containing 63 wt% of ethanol, 7 wt% of ethyl acetate, 28 wt% of water and 2 wt% of byproducts at the tower top, and obtaining a product containing 92 wt% of acetic acid, 6.6 wt% of water and 1.4 wt% of byproducts at the tower bottom;
(B) introducing the first tower top product into a crude separation tower, and obtaining a product containing 71.6 wt% of ethyl acetate, 5.8 wt% of ethanol and 7.8 wt% of water at the tower top; introducing the material at the top of the crude separation tower into a liquid-liquid separator 6, introducing 4000kg/h of water at 25 ℃ from the top of the liquid-liquid separator 6, standing and separating to obtain a water phase and an oil phase, introducing the oil phase into an ethyl acetate rectifying tower 7, and obtaining a product containing ethyl acetate at the bottom of the tower, wherein the purity of the ethyl acetate is 91.5 wt%, the water content is 5.4 wt%, and the recovery rate of the ethyl acetate is 88.9%; light components containing byproducts are obtained at the tower top;
roughly separating the tower bottom to obtain 63.8 wt% ethanol and 35.1 wt% water; and introducing the bottom product of the crude separation tower into an ethanol rectifying tower, and obtaining 92.4 wt% of ethanol and 6.5 wt% of water at the top of the ethanol rectifying tower, wherein the recovery rate of the ethanol is 96.7%.
Wherein, in the steps (A) to (B), the byproduct is one or more of acetaldehyde, acetic acid, n-propanol, acetone, methanol, isopropanol, ethane, carbon monoxide, carbon dioxide, propionic acid, butyric acid, 1-butanol, valeric acid, 2-pentanoic acid, diethyl ether, 2-butanol and hexanoic acid;
wherein, the operation conditions of the acetic acid separation tower, the crude separation tower, the glycol extraction tower, the extractant recovery tower, the ethanol rectification tower and the ethyl acetate rectification tower are shown in table 6.
Table 6.
The total load of the overhead coolers of the acetic acid separation column and the ethyl acetate rectification column, and the total load of the reboiler at the bottom of the column were calculated, and the results are shown in table 7.
TABLE 7
| Examples | Total load of condenser, MW | Total reboiler duty, MW | Total load, MW |
| Example 1 | 156.27 | 192.11 | 348.38 |
| Example 2 | 165.8 | 198.12 | 363.92 |
| Example 3 | 168.79 | 206.58 | 375.37 |
| Comparative example 1 | 193.59 | 230.8 | 424.39 |
| Comparative example 2 | 180.86 | 217.08 | 387.94 |
The results in table 7 show that the method and the device provided by the invention can effectively reduce the energy consumption for separating the ethanol crude product by acetic acid hydrogenation. For example, 30 ten thousand tons/year of crude ethanol products obtained by hydrogenating acetic acid shown in Table 1 are extracted by adding only glycol (comparative example 1) or only water (comparative example 2), the method of the invention obviously reduces the separation energy consumption, the total load of the top and the bottom of an acetic acid separation tower, a crude separation tower, a glycol extraction tower, an extractant recovery tower, an ethanol rectification tower and an ethyl acetate rectification tower is calculated (the load heat of a heater is from the material flow at the bottom of the ethanol rectification tower, which belongs to the comprehensive utilization of the internal heat and can not be considered; the load of a cooler is smaller, which can be ignored compared with a condenser at the top of the tower or a reboiler at the bottom of the tower), the total energy consumption is reduced by 18 percent to the maximum extent, specifically, the energy consumption of a condenser at the top of the tower is reduced by 19.3 percent to the maximum, the energy consumption of a reboiler at the bottom of the tower is, after the tower runs smoothly, the ethylene glycol can be completely recycled without adding (additionally adding) ethylene glycol. Moreover, the method and the device can obtain ethanol and ethyl acetate products with higher purity and recovery rate.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (11)
1. A method for reducing the separation energy consumption of an ethanol crude product prepared by acetic acid hydrogenation comprises the following steps:
(A) preheating an ethanol crude product obtained by acetic acid hydrogenation, introducing the ethanol crude product into an acetic acid separation tower (1), obtaining a first tower top product containing ethanol, ethyl acetate and water at the tower top, introducing the first tower top product into a crude separation tower (2), obtaining a second tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a second tower bottom product containing ethanol and water at the tower bottom; feeding the second bottom product into an ethanol rectifying tower (5);
(B) introducing ethylene glycol and the second tower top product into an ethylene glycol extraction tower (3) for first extraction, obtaining a third tower top product containing ethyl acetate, water and ethanol at the tower top, and obtaining a third tower bottom product containing ethylene glycol and ethanol at the tower bottom;
(C) introducing the third bottom product into an extractant recovery tower (4), and obtaining a fourth top product containing ethanol and water at the top of the tower; introducing the fourth tower top product into an ethanol rectifying tower (5), and obtaining a product containing ethanol at the tower top of the ethanol rectifying tower (5);
(D) and (3) introducing water and the third tower top product into a liquid-liquid separator (6) for second extraction to obtain a water phase and an oil phase, introducing the oil phase into an ethyl acetate rectifying tower (7), obtaining a product containing ethyl acetate at the tower bottom, and obtaining a light component at the tower top.
2. The process of claim 1, wherein the weight ratio of ethylene glycol to second overhead product, calculated as ethanol, is (0.2-0.3): 1; and/or the presence of a gas in the gas,
the weight ratio of the water to the third tower top product calculated by ethyl acetate is (0.2-0.4): 1.
3. the method of claim 1, wherein the method further comprises: and carrying out gas-liquid separation on an ethanol crude product prepared by acetic acid hydrogenation to obtain liquid-phase crude ethanol, and preheating the liquid-phase crude ethanol.
4. The method of claim 1, wherein the method further comprises: and (3) introducing a fourth bottom product containing ethylene glycol obtained from the bottom of the extractant recovery tower (4) into the ethylene glycol extraction tower (3) for recycling.
5. The method of claim 1, wherein the method further comprises: cooling at least part of water obtained at the bottom of the ethanol rectifying tower (5) and then introducing the cooled water into a liquid-liquid separator (6), wherein the cooling temperature is preferably 20-40 ℃.
6. The method of claim 1, wherein the method further comprises: the aqueous phase is passed to a crude separation column (2).
7. The process according to any one of claims 1 to 6, wherein the operating conditions of the acetic acid separation column (1) comprise: the temperature at the top of the tower is 70-100 ℃, and preferably 79-89 ℃; the temperature of the tower bottom is 105-140 ℃, and preferably 119-129 ℃; the pressure at the top of the tower is 0.03-0.2 MPa, preferably 0.08-0.12 MPa; the pressure at the bottom of the tower is 0.09-0.3 MPa, preferably 0.13-0.17 MPa; the number of the tower plates is 10-40, and preferably 20-30; the reflux ratio is 2-7, preferably 2.5-5; and/or the presence of a gas in the gas,
the operating conditions of the rough separation tower (2) comprise: the temperature at the top of the tower is 40-75 ℃, and preferably 58-70 ℃; the temperature of the tower bottom is 76-100 ℃, and preferably 80-89 ℃; the pressure at the top of the tower is 0.02-0.12 MPa, preferably 0.06-0.1 MPa; the pressure at the bottom of the tower is 0.08-0.2 MPa, preferably 0.1-0.14 MPa; the number of the tower plates is 10-40, and preferably 20-30; the reflux ratio is 2-8, preferably 3-6; and/or the presence of a gas in the gas,
the operating conditions of the ethylene glycol extraction column (3) include: the temperature at the top of the tower is 20-60 ℃, and the preferable temperature is 28-49 ℃; the temperature of the tower bottom is 60-90 ℃, and preferably 63-76 ℃; the pressure at the top of the tower is 0.01-0.1 MPa, preferably 0.02-0.05 MPa; the pressure at the bottom of the tower is 0.02-0.1 MPa, preferably 0.04-0.07 MPa; the number of the tower plates is 30-80, preferably 50-63; the reflux ratio is 2-15, preferably 5-12; and/or the presence of a gas in the gas,
the operating conditions of the extractant recovery column (4) comprise: the temperature at the top of the tower is 60-100 ℃, and preferably 74-86 ℃; the temperature of the tower bottom is 160-240 ℃, and 193-206 ℃ is preferred; the pressure at the top of the tower is 0.02-0.15 MPa, preferably 0.06-0.1 MPa; the pressure at the bottom of the tower is 0.05-0.2 MPa, preferably 0.09-0.13 MPa; the number of the tower plates is 8-30, and preferably 12-20; the reflux ratio is 1-10, preferably 2-5; and/or the presence of a gas in the gas,
the operating conditions of the ethanol rectification column (5) comprise: the temperature at the top of the tower is 60-85 ℃, and preferably 73-80 ℃; the temperature of the tower bottom is 90-120 ℃, and preferably 94-103 ℃; the pressure at the top of the tower is 0.05-0.15 MPa, preferably 0.08-0.11 MPa; the pressure at the bottom of the tower is 0.08-0.2 MPa, preferably 0.1-0.14 MPa; the number of the tower plates is 20-50, preferably 33-40; the reflux ratio is 2-10, preferably 4-8; and/or the presence of a gas in the gas,
the operating conditions of the ethyl acetate rectifying tower (7) comprise: the temperature at the top of the tower is 15-50 ℃, and the preferable temperature is 23-35 ℃; the temperature of the tower bottom is 60-90 ℃, and preferably 64-76 ℃; the pressure at the top of the tower is 0.05-0.15 MPa, preferably 0.06-0.09 MPa; the pressure at the bottom of the tower is 0.05-0.2 MPa, preferably 0.08-0.12 MPa; the number of the tower plates is 10-30, preferably 14-22; the reflux ratio is 2-10, preferably 3-9; and/or the presence of a gas in the gas,
the preheating temperature in the step (A) is 30-50 ℃, and preferably 40-45 ℃.
8. An apparatus for reducing energy consumption for separation of a crude ethanol product from acetic acid hydrogenation, wherein the apparatus comprises: an acetic acid separation tower (1), a crude separation tower (2), an ethylene glycol extraction tower (3), an extractant recovery tower (4), an ethanol rectification tower (5), a liquid-liquid separator (6) and an ethyl acetate rectification tower (7), wherein,
the acetic acid separation tower (1) is used for separating an ethanol crude product obtained by acetic acid hydrogenation, a first tower top product containing ethanol, ethyl acetate and water is obtained at the tower top, and the first tower top product is introduced into the crude separation tower (2);
the rough separation tower (2) is used for separating the first tower top product, a second tower top product containing ethyl acetate, water and ethanol is obtained at the tower top, and a second tower bottom product containing ethanol and water is obtained at the tower bottom; feeding the second bottom product into an ethanol rectifying tower (5);
the ethylene glycol extraction tower (3) is used for carrying out first extraction on the second tower top product through ethylene glycol, a third tower top product containing ethyl acetate, water and ethanol is obtained at the tower top, and a third tower bottom product containing ethylene glycol and ethanol is obtained at the tower bottom;
the extractant recovery tower (4) is used for separating the third bottom product to obtain a fourth top product containing ethanol and water at the top of the tower;
the ethanol rectifying tower (5) is used for carrying out ethanol separation on the second tower bottom product and the fourth tower top product to obtain a product containing ethanol;
a liquid-liquid separator (6) for performing a second extraction on the third overhead product with water to obtain a water phase and an oil phase;
and the ethyl acetate rectifying tower (7) is used for separating the oil phase, a product containing ethyl acetate is obtained at the bottom of the tower, and a light component is obtained at the top of the tower.
9. The device of claim 8, further comprising a gas-liquid separator for performing gas-liquid separation on the ethanol crude product obtained by hydrogenating acetic acid to obtain liquid-phase crude ethanol;
preferably, the tower bottom outlet of the gas-liquid separator is communicated with the inlet of the acetic acid separation tower (1), and the tower bottom outlet of the acetic acid separation tower (1) is communicated with the inlet of the crude separation tower (2);
preferably, the device also comprises a heater (8) for heating the liquid phase crude ethanol and then introducing the liquid phase crude ethanol into the acetic acid separation tower (1).
10. The device according to claim 8 or 9, wherein the bottom outlet of the crude separation column (2) is communicated with the inlet of the ethanol rectification column (5), and the top outlet is communicated with the inlet of the glycol extraction column (3); an outlet at the top of the ethylene glycol extraction tower (3) is communicated with an inlet of the liquid-liquid separator (6), and an outlet at the bottom of the ethylene glycol extraction tower is communicated with an inlet of the extractant recovery tower (4); an outlet at the top of the extractant recovery tower (4) is communicated with an inlet of the ethanol rectifying tower (5), and an outlet at the bottom of the extractant recovery tower is communicated with an inlet of the glycol extraction tower (3); the outlet at the bottom of the ethanol rectifying tower (5) is communicated with the inlet of the liquid-liquid separator (6); the water phase outlet of the liquid-liquid separator (6) is communicated with the inlet of the crude separation tower (2), and the oil phase outlet is communicated with the inlet of the ethyl acetate rectifying tower (7).
11. The apparatus according to claim 10, wherein the apparatus further comprises a cooler (9) for cooling at least a portion of the water obtained from the bottom of the ethanol distillation column (5) and passing the cooled portion to the liquid-liquid separator (6).
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102399130A (en) * | 2011-12-13 | 2012-04-04 | 西南化工研究设计院 | Method for simplifying rectification process for preparing ethanol through hydrogenation of acetic acid |
| WO2012149164A1 (en) * | 2011-04-26 | 2012-11-01 | Celanese International Corporation | Process for controlling a reboiler during alcohol recovery and reduced ester formation |
| WO2013070210A1 (en) * | 2011-11-09 | 2013-05-16 | Celanese International Corporation | Integrated carbonylation and hydrogenation process to obtain ethanol having flashing to recover acid production catalyst |
| CN103265402A (en) * | 2013-05-21 | 2013-08-28 | 江苏金聚合金材料有限公司 | Method for reducing energy consumption in technological process of preparing ethyl alcohol through acetic ester hydrogenation |
| CN105439819A (en) * | 2014-08-27 | 2016-03-30 | 中国石油化工股份有限公司 | A separating process for ethanol production by methyl acetate hydrogenation |
-
2019
- 2019-06-28 CN CN201910577542.8A patent/CN112142562B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012149164A1 (en) * | 2011-04-26 | 2012-11-01 | Celanese International Corporation | Process for controlling a reboiler during alcohol recovery and reduced ester formation |
| WO2013070210A1 (en) * | 2011-11-09 | 2013-05-16 | Celanese International Corporation | Integrated carbonylation and hydrogenation process to obtain ethanol having flashing to recover acid production catalyst |
| CN102399130A (en) * | 2011-12-13 | 2012-04-04 | 西南化工研究设计院 | Method for simplifying rectification process for preparing ethanol through hydrogenation of acetic acid |
| CN103265402A (en) * | 2013-05-21 | 2013-08-28 | 江苏金聚合金材料有限公司 | Method for reducing energy consumption in technological process of preparing ethyl alcohol through acetic ester hydrogenation |
| CN105439819A (en) * | 2014-08-27 | 2016-03-30 | 中国石油化工股份有限公司 | A separating process for ethanol production by methyl acetate hydrogenation |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113582887A (en) * | 2021-08-17 | 2021-11-02 | 辛集市北方化工有限公司 | Purification method and purification system of crude petroleum sodium sulfonate |
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