CN114478193A - Separation method and separation device for preparing ethanol from dimethyl ether - Google Patents
Separation method and separation device for preparing ethanol from dimethyl ether Download PDFInfo
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Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
- C07C29/76—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
- C07C29/80—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment by distillation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
- C07C29/76—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
Abstract
The invention discloses a separation method and a separation device for preparing ethanol from dimethyl ether, wherein the separation method comprises the following steps: the separation method has the advantages that the product components are thoroughly separated, the separation method is recycled, and meanwhile, a process combining a bulkhead rectification technology and a double-effect rectification technology is adopted, so that the separation efficiency is improved to the maximum extent, and the operation energy consumption is saved to the maximum extent.
Description
Technical Field
The invention relates to the field of product separation in a process route for preparing ethanol from dimethyl ether in the technology of preparing ethanol from coal, in particular to a separation method and a separation device for preparing ethanol from dimethyl ether.
Background
Ethanol is an important bulk chemical product and is widely used in the industries of medicine, food, fuel, chemical industry and the like. Worldwide, the production process of ethanol comprises a biological fermentation method, a petrochemical method and a coal chemical method. One of the most promising uses of ethanol products is to blend with gasoline to produce ethanol gasoline, the fuel ethanol has high oxygen content and good anti-knock performance, and can be fully combusted to reduce pollutant emission. The ethanol production is vigorously developed, and the environmental protection pressure of over high external dependence of China on petroleum, haze treatment and the like can be effectively relieved.
In the production process of ethanol, the fermentation process route is widely applied internationally and in China, and large-scale ethanol production enterprises mostly adopt grain or economic crop fermentation processes. Corn is used as a raw material in the United states, sugarcane is used as a raw material in Brazil, and wheat and beet are used as main raw materials in European union countries. The rapid expansion of fuel ethanol production capacity will greatly increase the demand for the above-mentioned grain and economic crops. In recent years, global grain prices continue to rise greatly, which causes general attention of international society, and the question about grain safety is higher and higher.
Influenced by the 'grain crisis', the new corn fuel ethanol project is stopped to be approved in China at present. The cellulose fuel ethanol project fermented by cassava and corn straws has poor economic benefit due to high production cost and dependence on national subsidies and other factors. The petrochemical route uses ethylene as raw material to prepare fuel ethanol by ethylene hydration method. China depends on import of a large amount of petroleum, and the price of ethylene restricts the application and popularization of the method in China.
The coal chemical industry route ethanol preparation method is a method for preparing synthesis gas and methanol by taking coal as a raw material, and then preparing ethanol by a dimethyl ether method or an acetic acid method. The ethanol preparation by the acetic acid method is divided into direct acetic acid hydrogenation for preparing ethanol and acetic ester hydrogenation for preparing ethanol, the two methods both need an intermediate raw material of acetic acid, the economical efficiency of an ethanol product is greatly influenced by the acetic acid product, and meanwhile, the production cost is higher. The dimethyl ether method for preparing ethanol has no production link of acetic acid, methanol is subjected to dehydration reaction to synthesize dimethyl ether, dimethyl ether and carbon monoxide are subjected to dimethyl ether carbonylation reaction under the action of a catalyst to synthesize methyl acetate, the methyl acetate and hydrogen are subjected to hydrogenation reaction to generate crude ethanol, and the crude ethanol is separated and refined to obtain the product ethanol. The process can solve the problem of surplus methanol productivity in China, and the process route mainly adopts a molecular sieve catalyst or a copper-based catalyst, does not need a noble metal catalyst and has relatively low production cost; only trace amount of acetic acid is generated in the whole reaction process, and the corrosion degree to equipment is very low, so that no special requirement is made on equipment materials.
In recent years, the process for preparing ethanol by carbonylation and hydrogenation of dimethyl ether is continuously developed and industrially advanced in China, a demonstration project of preparing ethanol by carbonylation and hydrogenation of dimethyl ether with annual output of 10 million tons/year, which is jointly developed by a large-chain compound institute and a prolonged petroleum group, is adopted to open all processes in 2017, 1 month and 11 days, qualified absolute ethyl alcohol is produced, and long-time stable operation is realized.
In the process for preparing the ethanol by the carbonylation and hydrogenation of the dimethyl ether, the energy consumption of a separation working section of a reaction product is relatively high, and a high-efficiency and energy-saving separation process is researched according to the material characteristics of the process, so that the process has great significance for the ethanol production process.
The baffle plate rectifying technology belongs to the high-efficiency rectifying technology, a vertical baffle plate is arranged in a common rectifying tower, and the baffle plate can ensure that a single tower realizes the functions of two towers, avoid the back mixing of the concentration of intermediate components in the flow of the two towers and improve the thermodynamic efficiency, thereby greatly reducing the energy consumption. The double-effect rectification technology belongs to an efficient rectification energy-saving process, and a reboiler of a low-temperature tower is heated by using the condensation heat of tower top materials with high temperature in a device, so that the energy-saving effect is obvious. Under some specific conditions, the two energy-saving technologies are combined to achieve the best energy-saving effect.
Disclosure of Invention
In order to solve the problem of separation energy consumption in the process of preparing ethanol by carbonylation and hydrogenation of dimethyl ether in the prior art, the invention provides a high-efficiency and energy-saving separation method and a separation device for preparing ethanol by carbonylation and hydrogenation of dimethyl ether.
The specific technical scheme of the invention is as follows:
1. a separation method for preparing ethanol from dimethyl ether comprises the following steps:
the method comprises the following steps of enabling a reaction product of the dimethyl ether and the ethanol to enter a rectification separation system to obtain a hydrous ethanol product, wherein the rectification separation system comprises a degassing tower, a pre-separation tower, an ethanol tower and a methanol recovery tower, enabling the reaction product of the dimethyl ether and the ethanol to enter the degassing tower, collecting a light component material flow from the top of the degassing tower, and collecting a tower bottom material flow from the bottom of the tower;
the tower bottom material flow enters a pre-separation tower for separation, a methanol material flow containing methyl acetate and ethyl acetate is extracted from the tower top, and an ethanol material flow containing the rest methanol is extracted from the tower bottom;
separating the ethanol material flow containing the rest methanol in an ethanol tower, extracting a water-containing ethanol product from a side line of the tower, extracting a methanol material flow from the top of the tower, and extracting a heavy component material flow from the bottom of the tower;
and the methanol material flow containing methyl acetate and ethyl acetate extracted from the top of the pre-separation tower and the methanol material flow containing methanol extracted from the top of the ethanol tower enter a methanol recovery tower to be separated, the material flow containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product is extracted from the bottom of the tower.
2. The separation process according to item 1, wherein the rectification system further comprises an ethanol recovery tower, heavy component streams extracted from the bottom of the ethanol tower enter the ethanol recovery tower for separation, and ethanol streams are extracted from the top of the ethanol tower.
3. The separation process of claim 1 or 2, wherein the aqueous ethanol product is passed into a molecular sieve adsorption dehydration system to obtain an anhydrous ethanol product.
4. The separation process according to item 2 or 3, wherein the recovered ethanol stream withdrawn from the top of the ethanol recovery column is passed to an ethanol column for separation.
5. The separation process of any of claims 1-4, wherein the dimethyl ether to ethanol reaction product comprises methanol, ethanol, methyl acetate, ethyl acetate, propanol, butanol, and dimethyl ether.
6. The separation method according to item 5, wherein the methanol is 30-70% and the ethanol is 30-70% by mass of the reaction product of dimethyl ether-to-ethanol.
7. The separation process according to any one of claims 2 to 6, wherein the operating pressure of the degasser column is 1 to 1000kPa, the operating pressure of the preseparator column is 1 to 1000kPa, the operating pressure of the ethanol recovery column is 1 to 1000kPa, and the operating pressure of the methanol recovery column is 1 to 1000 kPa.
8. The separation process of any of claims 1-7, wherein the absolute ethanol product has a purity of 90-99.999%.
9. The separation process of any one of claims 1 to 8, wherein the methanol product has a purity of 85 to 99.999%.
10. The separation process according to any one of claims 1 to 9, wherein the overhead vapor of the pre-separation column is used as a reboiler heat source for the ethanol column and the methanol recovery column.
11. A separation device for preparing ethanol from dimethyl ether, wherein,
the separation device comprises a rectification separation system, and the rectification separation system comprises a degassing tower, a pre-separation tower, an ethanol tower and a methanol recovery tower;
the pipeline of the dimethyl ether-to-ethanol reaction product material flow is connected with a feed inlet of the degassing tower so as to be used for feeding the dimethyl ether-to-ethanol reaction product material flow into the degassing tower for separation, collecting a light component material flow from the top of the degassing tower and collecting a tower bottom material flow from the bottom of the degassing tower;
the pipeline of the tower bottom material flow is connected with the feed inlet of the pre-separation tower so as to be used for feeding the tower bottom material flow into the pre-separation tower for separation, a methanol material flow containing methyl acetate and ethyl acetate is extracted from the tower top of the pre-separation tower, and an ethanol material flow containing the rest methanol is extracted from the tower bottom;
a pipeline of the ethanol material flow containing the rest part of the methanol is connected with a feed inlet of the ethanol tower, an aqueous ethanol product is extracted from a tower side line of the ethanol tower, a methanol material flow is extracted from the top of the tower, and a heavy component material flow is extracted from the bottom of the tower;
a pipeline of the methanol material flow containing methyl acetate and ethyl acetate and a pipeline of the methanol material flow containing methanol are connected with a feed inlet of the methanol recovery tower so as to be used for separating the methanol material flow containing methyl acetate and ethyl acetate and the methanol material flow containing methanol into the methanol recovery tower, the material flow containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product is extracted from the bottom of the tower.
12. The separation device of item 11, wherein,
the rectification separation system also comprises an ethanol recovery tower, and a pipeline of the heavy component material flow is connected with a feed inlet of the ethanol recovery tower so as to be used for feeding the heavy component material flow into the ethanol recovery tower for separation and recovering the ethanol material flow from the top of the tower.
13. The separation device of item 11 or 12, wherein,
the separation device also comprises a molecular sieve adsorption and dehydration system, and the pipeline of the hydrous ethanol product is connected with the feed inlet of the molecular sieve adsorption and dehydration system so as to obtain the anhydrous ethanol product.
14. The separation device of claim 12 or 13, wherein the line for recovering the ethanol stream is connected to the feed port of the ethanol column for feeding the recovered ethanol stream to the ethanol column for separation.
15. The separation device according to any one of the items 11 to 14, wherein the ethanol tower is a clapboard rectifying tower, a vertical clapboard is arranged in the clapboard rectifying tower, the inside of the clapboard rectifying tower is divided into a1 st area for feeding, a 2 nd area for public rectification, a 3 rd area for discharging and a 4 th area for public stripping, preferably, a pipeline of an ethanol stream containing the rest part of methanol is connected with the 1 st area of the ethanol tower, a methanol-containing stream is extracted from the 2 nd area, a water-containing ethanol product is extracted from the 3 rd area, and a heavy component stream is extracted from the 4 th area, preferably, a pipeline for recovering the ethanol stream is connected with the 4 th area or the 1 st area of the ethanol tower.
16. The separation device according to any one of claims 11 to 15, wherein the top of the pre-separation tower is connected with reboilers of an ethanol tower and a methanol recovery tower through pipelines respectively, so that steam at the top of the pre-separation tower is used as a heat source of the reboilers of the ethanol tower and the methanol recovery tower.
ADVANTAGEOUS EFFECTS OF INVENTION
The invention provides an efficient and energy-saving separation process for preparing ethanol from dimethyl ether for the first time, so that an absolute ethanol product is obtained, and meanwhile, light components such as recycled methanol, a mixture of methyl acetate and ethyl acetate, dimethyl ether and the like are obtained. The product components are separated thoroughly, and the process combining the bulkhead rectification technology and the double-effect rectification technology is adopted while the product components are recycled, so that the separation efficiency is improved to the maximum degree, and the operation energy consumption is saved to the maximum degree.
Drawings
FIG. 1 is a schematic view of a separation apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic view of another separation apparatus according to an embodiment of the present invention
Figure 3 is a schematic diagram of an ethanol column bulkhead rectification column.
Wherein, T1-degasser, T2-preseparator; t3-ethanol column; t4-methanol recovery column; t5-ethanol recovery column; a1-molecular sieve adsorption dehydration system; E101-T1 condenser; E102-T1 reboiler; E202-T2 reboiler; E301-T3 condenser; E302-T3 reboiler; E401-T4 condenser; E402-T4 reboiler; E501-T5 condenser; e502-reboiler; s101-dimethyl ether-to-ethanol reaction product material flow; s102 — a light component stream; s103-bottom stream; s201-a methanol stream containing methyl acetate and ethyl acetate; s202-an ethanol stream containing the remaining portion of methanol; s301-a methanol-containing stream; s302-aqueous ethanol product; s303-a heavies stream; s401-a stream comprising methyl acetate and ethyl acetate; s402-methanol product; s501-recovering an ethanol stream; s502-heavy contaminant stream; s601-absolute ethanol product; s602-waste Water
Detailed Description
The present invention is described in detail in the following description of embodiments with reference to the figures, in which like numbers represent like features throughout the figures. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It should be noted that certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, various names may be used to refer to a component. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description which follows is a preferred embodiment of the invention, however, the description is given for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the present invention is defined by the appended claims.
The invention provides a separation method for preparing ethanol by methyl acetate hydrogenation, which comprises the following steps:
enabling a reaction product of preparing ethanol from dimethyl ether to enter a rectification separation system to obtain a water-containing ethanol product, wherein the rectification separation system comprises a degassing tower, a pre-separation tower, an ethanol tower and a methanol recovery tower, the reaction product of preparing ethanol from dimethyl ether enters the degassing tower, a light component material flow is extracted from the top of the tower, and a tower bottom material flow is extracted from the bottom of the tower;
the tower bottom material flow enters a pre-separation tower for separation, a methanol material flow containing methyl acetate and ethyl acetate is extracted from the tower top, and an ethanol material flow containing the rest methanol is extracted from the tower bottom;
separating the ethanol material flow containing the rest methanol in an ethanol tower, extracting a water-containing ethanol product from a side line of the tower, extracting a methanol material flow from the top of the tower, and extracting a heavy component material flow from the bottom of the tower;
and the methanol material flow containing methyl acetate and ethyl acetate extracted from the top of the pre-separation tower and the methanol material flow containing methanol extracted from the top of the ethanol tower enter a methanol recovery tower to be separated, the material flow containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product is extracted from the bottom of the tower.
The light component stream refers to a light component stream containing dimethyl ether or the like.
The bottom stream refers to the stream of the dimethyl ether-to-ethanol product except light components after being separated in the degassing tower.
The ethanol stream withdrawn from the bottom of the pre-separation column containing the remaining part of the methanol contains small amounts of methanol, ethanol and heavy alcohols.
The light component and the methanol stream containing methyl acetate and ethyl acetate can be returned to the upstream reaction system for continuous reaction.
In one embodiment, the rectification system further comprises an ethanol recovery tower, wherein a heavy component stream extracted from the bottom of the ethanol tower enters the ethanol recovery tower for separation, an ethanol stream is extracted from the top of the tower, and a heavy impurity stream is extracted from the bottom of the tower.
The invention can obtain purer ethanol product after separating the reaction product of preparing ethanol from dimethyl ether, and the obtained methanol product, the material flow containing methyl acetate and ethyl acetate and the heavy alcohol can be returned to the upstream reaction system for reaction, thus the components of the product are separated thoroughly.
In one embodiment, the anhydrous ethanol product is obtained after the aqueous ethanol product is fed into a molecular sieve adsorption dehydration system.
The molecular sieve adsorption dehydration system is a molecular sieve adsorption dehydration system commonly used by those skilled in the art, and those skilled in the art can select the molecular sieve adsorption dehydration system according to needs, for example, the molecular sieve adsorption dehydration system may be a liquid phase adsorption dehydration system or a gas phase adsorption dehydration system.
In one embodiment, the recovered ethanol stream withdrawn from the top of the ethanol recovery column is passed to an ethanol column for separation.
In one embodiment, the dimethyl ether to ethanol reaction product comprises methanol, ethanol, methyl acetate, ethyl acetate, propanol, butanol, and dimethyl ether.
In one embodiment, the methanol accounts for 30-70% and the ethanol accounts for 30-70% of the total weight of the reaction product of the dimethyl ether to ethanol, and the content of methyl acetate and ethyl acetate is preferably less than 10%. The water content is less than 5 percent, the content of heavy alcohols such as propanol and the like is less than 5 percent, and the content of light components such as dimethyl ether and the like is less than 5 percent.
For example, the methanol can be 30%, 40%, 50%, 60%, 70%, etc., based on the total weight of the dimethyl ether-to-ethanol reaction product; the ethanol may be 30%, 40%, 50%, 60%, 70%, etc.
In one embodiment, the degasser is operated at a pressure of 1 to 1000kPa with a reflux ratio of 1 to 50; the operation pressure of the pre-separation tower is 1-1000kPa, and the reflux ratio is 1-20; the operating pressure of the ethanol tower is 1-1000kPa, and the reflux ratio is 1-100; the operation pressure of the ethanol recovery tower is 1-1000kPa, and the reflux ratio is 1-20; the operating pressure of the methanol recovery tower is 1-1000kPa, and the reflux ratio is 1-10.
In one embodiment, the absolute ethanol product has a purity of 90 to 99.999%.
In one embodiment, the purity of the methanol product is from 85 to 99.999%.
In one embodiment, the overhead vapor of the pre-separation column is used as the reboiler heat source for the ethanol column and the methanol recovery column.
The invention can obtain the absolute ethyl alcohol product by using the separation method, the product is separated thoroughly, and the tower top steam of the pre-separation tower is used as a reboiler heat source of the ethyl alcohol tower and the methanol recovery tower, so that the operation energy consumption can be reduced to the maximum extent.
As shown in fig. 1, the invention provides a separation device for preparing ethanol from dimethyl ether, which comprises a rectification separation system (not shown in the figure), wherein the rectification separation system comprises a degasser T1, a pre-separation tower T2, an ethanol tower T3 and a methanol recovery tower T4;
a pipeline of the dimethyl ether-to-ethanol reaction product stream S101 is connected with a feed inlet of a degassing tower T1 for feeding the dimethyl ether-to-ethanol reaction product stream S101 into a degassing tower T1 for separation, a light component stream S102 is extracted from the top of the degassing tower T1, and a bottom stream S103 is extracted from the bottom of the degassing tower T1, preferably, the light component stream S102 refers to a stream of light components such as dimethyl ether, the bottom stream S103 refers to a stream obtained after removing the light components, and the light component stream S102 is returned to an upstream reaction system for continuous reaction;
the pipeline of the bottom material S103 is connected with the feed inlet of the pre-separation tower T2 so as to be used for feeding the bottom material S103 into the pre-separation tower T2 for separation, a methanol material stream S201 containing methyl acetate and ethyl acetate is extracted from the top of the pre-separation tower T2, and an ethanol material stream S202 containing the rest part of methanol is extracted from the bottom of the pre-separation tower T2; preferably, the ethanol stream S202 containing the remaining portion of methanol comprises ethanol, heavy alcohols and small amounts of methanol;
a pipeline of the ethanol stream S202 containing the rest part of the methanol is connected with the feed inlet of the ethanol tower T3 so as to feed the ethanol stream S202 containing the rest part of the methanol into the ethanol tower T3 for separation, an aqueous ethanol product S302 is extracted from the side line of the ethanol tower, a methanol stream S301 is extracted from the top of the tower, and a heavy component stream S303 is extracted from the bottom of the tower; preferably, the heavies stream S303 comprises residual aqueous ethanol and heavy alcohols;
a pipeline of the methanol material flow S201 containing methyl acetate and ethyl acetate and a pipeline of the methanol material flow S301 are connected with the feed inlet of the methanol recovery tower T4 so as to be used for feeding the methanol material flow S201 containing methyl acetate and ethyl acetate and the material flow S301 containing methanol into the methanol recovery tower T4 for separation, a material flow S401 containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product S402 is extracted from the bottom of the tower.
The purity of the obtained methanol product S402 is 85-99.999%.
In one embodiment, as shown in fig. 2, the rectification separation system further comprises an ethanol recovery column T5, and the pipeline of the heavy component stream S303 is connected with the feed inlet of the ethanol recovery column T5 for feeding the heavy component stream S303 to the ethanol recovery column T5 for separation, recovering an ethanol stream S501 from the top of the column, and recovering a heavy impurity stream S502 from the bottom of the column.
In one embodiment, as shown in fig. 1 and fig. 2, the separation device further comprises a molecular sieve adsorption dehydration system a1, and the pipeline of the aqueous ethanol product S302 is connected with the feed inlet of the molecular sieve adsorption dehydration system a1 for obtaining the anhydrous ethanol product S601 and the wastewater S602.
The purity of the separated ethanol product S601 is 90-99.999%.
By adopting the separation device, the ethanol and other components can be thoroughly separated, and a relatively pure ethanol product is obtained.
In one embodiment, the line for recovering the ethanol stream S501 is connected to the feed port of the ethanol column T3 for passing the recovered ethanol stream S501 to the ethanol column T3 for separation for recovering ethanol.
Preferably, the pipeline for recovering the ethanol stream S501 is connected with a feed inlet in the middle or lower part of the ethanol tower T3 for feeding the recovered ethanol stream S501 into the ethanol tower T3 for separation for recovering ethanol.
In one embodiment, the ethanol column T3 is a baffle distillation column, as shown in fig. 3, a vertical baffle is arranged in the baffle distillation column to divide the column into a1 st zone for feeding, a 2 nd zone for common distillation, a 3 rd zone for discharging and a 4 th zone for common distillation, preferably, a pipeline of an ethanol stream S202 containing the rest part of methanol is connected with the 1 st zone of the ethanol column T3, a methanol-containing stream S301 is extracted from the 2 nd zone, an aqueous ethanol product S302 is extracted from the 3 rd zone, a heavy component stream S303 is extracted from the 4 th zone, and preferably, a pipeline of an ethanol stream S501 is connected with the 4 th zone or the 1 st zone (not shown in fig. 2) of the ethanol column T3.
In one embodiment, the top of the pre-separation column T2 is connected by lines to reboilers E302 and E402 of ethanol column T3 and methanol recovery column T4, respectively, to use the vapor at the top of the pre-separation column T2 as the heat source for the reboilers of ethanol column T3 and methanol recovery column T4.
In one embodiment, the degasser is operated at a pressure of 1 to 1000kPa with a reflux ratio of 1 to 50; the operation pressure of the pre-separation tower is 1-1000kPa, and the reflux ratio is 1-20; the operating pressure of the ethanol tower is 1-1000kPa, and the reflux ratio is 1-100; the operation pressure of the ethanol recovery tower is 1-1000kPa, and the reflux ratio is 1-20; the operating pressure of the methanol recovery tower is 1-1000kPa, and the reflux ratio is 1-10.
The reboiler of the ethanol tower and the methanol recovery tower is heated by the steam at the top of the pre-separation tower, and the reboilers of the ethanol tower and the methanol recovery tower do not use external heat sources, so that the energy consumption of the heat sources is saved.
The invention adopts the process of combining the bulkhead rectification technology and the double-effect rectification technology, thereby not only improving the separation efficiency, but also saving the operation energy consumption to the greatest extent.
In one embodiment, a condenser E101 is arranged between the top of the degasser T1 and the light ends stream S102 and a reboiler E102 is arranged at the bottom.
In one embodiment, a condenser E501 is provided between the top of the ethanol recovery column T5 and the recovered ethanol stream S501, and a reboiler E502 is provided at the bottom.
In one embodiment, a reboiler E202 is provided at the bottom of the pre-separation column T2, a condenser E301 is provided between the top of the ethanol column T3 and the methanol-containing stream S301, and a condenser E401 is provided between the top of the methanol recovery column T4 and the stream S401 containing methyl acetate and ethyl acetate.
In one embodiment, the ethanol column T3 may be in the form of internals as a pure packed column, as a pure tray column, or as a combined packed and tray column.
Examples
The invention is described generally and/or specifically for the materials used in the tests and the test methods, in the following examples,% means wt%, i.e. percent by weight, unless otherwise specified. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially.
Example 1
The device shown in FIG. 1 is used for separation, the flow rate is 72t/h, wherein the dimethyl ether-to-ethanol reaction product material flow S101 comprises 41 wt% of methanol, 52 wt% of ethanol, 5 wt% of methyl acetate and ethyl acetate, 1 wt% of water, 0.5 wt% of heavy alcohols such as propanol and 0.5 wt% of light components such as dimethyl ether.
The separation device comprises a rectification separation system (not shown in the figure) and a molecular sieve adsorption dehydration system A1, wherein the rectification separation system comprises a degassing tower T1, a pre-separation tower T2, an ethanol tower T3 and a methanol recovery tower T4;
a pipeline of the dimethyl ether-to-ethanol reaction product stream S101 is connected with a feed inlet of a degassing tower T1 and is used for feeding the dimethyl ether-to-ethanol reaction product stream S101 into a degassing tower T1 for separation, a light component stream S102 is taken out of the top of the degassing tower T1, and a bottom stream S103 is taken out of the bottom of the degassing tower T1;
the pipeline of the bottom material S103 is connected with the feed inlet of the pre-separation tower T2 and is used for feeding the bottom material S103 into a pre-separation tower T2 for separation, a methanol material flow S201 containing methyl acetate and ethyl acetate is extracted from the top of the pre-separation tower T2, and an ethanol material flow S202 containing the rest methanol is extracted from the bottom of the pre-separation tower T2;
the ethanol tower T3 is a clapboard rectifying tower (packed tower), as shown in figure 3, a vertical clapboard is arranged in the clapboard rectifying tower to divide the interior of the tower into a1 st zone for feeding, a 2 nd zone for public rectification, a 3 rd zone for discharging and a 4 th zone for public stripping, a pipeline of an ethanol material flow S202 containing the rest part of methanol is connected with the 1 st zone of the ethanol tower T3, a methanol-containing material flow S301 is extracted from the 2 nd zone, a water-containing ethanol product S302 is extracted from the 3 rd zone, and a heavy component material flow S303 is extracted from the 4 th zone;
a pipeline of the methanol material flow S201 containing methyl acetate and ethyl acetate and a pipeline of the methanol material flow S301 are connected with the feed inlet of the methanol recovery tower T4 so as to be used for feeding the methanol material flow S201 containing methyl acetate and ethyl acetate and the material flow S301 containing methanol into a methanol recovery tower T4 for separation, a material flow S401 containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product S402 is extracted from the bottom of the tower;
the pipeline of the hydrous ethanol product S302 is connected with the feed inlet of a molecular sieve adsorption dehydration system A1 to obtain an anhydrous ethanol product S601 and wastewater S602, the molecular sieve dehydration system comprises evaporation, adsorption, desorption and condensation equipment, and a 3A molecular sieve is used;
the top of the pre-separation tower T2 is respectively connected with reboilers E302 and E402 of an ethanol tower T3 and a methanol recovery tower T4 through pipelines so as to use steam at the top of the pre-separation tower T2 as heat sources of reboilers of an ethanol tower T3 and a methanol recovery tower T4;
a condenser E101 is arranged between the top of the degassing tower T1 and the light component stream S102, and a reboiler E102 is arranged at the bottom of the degassing tower T1;
a reboiler E202 is arranged at the bottom of the pre-separation tower T2, a condenser E301 is arranged between the top of the ethanol tower T3 and the stream S301 containing methanol, and a condenser E401 is arranged between the top of the methanol recovery tower T4 and the stream S401 containing methyl acetate and ethyl acetate.
The separation method comprises the following steps:
(1) the dimethyl ether-to-ethanol reaction product stream S101 enters a degassing tower T1 for separation, the operating pressure of the degassing tower T1 is 300kPa, the reflux ratio is 3.55, a light component stream S102 is extracted from the top of the tower, a bottom stream S103 is extracted from the bottom of the tower, the light component stream S102 comprises light components such as dimethyl ether, and the light component stream S102 returns to an upstream reaction system for continuous reaction;
(2) the bottom material flow S103 enters a pre-separation tower T2 for separation, the operating pressure of the pre-separation tower T2 is 180kPa, the reflux ratio is 2.97, a methanol material flow S201 containing methyl acetate and ethyl acetate is extracted from the top of the tower, and an ethanol material flow S202 containing the rest part of methanol is extracted from the bottom of the tower;
(3) the ethanol material flow S202 containing the residual part of the methanol enters an ethanol tower T3 for separation, the operation pressure of the ethanol tower T3 is 40kPa, the reflux ratio is 13.31, a methanol material flow S301 is extracted from a zone 2, an aqueous ethanol product S302 is extracted from a zone 3, and a heavy component material flow S303 is extracted from a zone 4;
(4) a methanol material flow S201 containing methyl acetate and ethyl acetate and a methanol material flow S301 containing methanol enter a methanol recovery tower T4 for separation, the operating pressure of the methanol recovery tower T4 is 50kPa, the reflux ratio is 7.00, a material flow S401 containing methyl acetate and ethyl acetate is extracted from the top of the tower, a methanol product S402 is extracted from the bottom of the tower, and the material flow S401 containing methyl acetate and ethyl acetate returns to an upstream reaction system for continuous reaction;
(5) the hydrous ethanol product S302 enters a molecular sieve adsorption dehydration system A1 for dehydration to obtain an anhydrous ethanol product S601 and wastewater S602;
after the separation is carried out by using the separation method and the separation device, the purity of the obtained methanol product is 99.9 percent, the ethanol content in the methanol product is 80ppm, the methanol content in the aqueous ethanol product is 400ppm, the heavy alcohol content is 200ppm, the ethanol purity is 99.9 percent, and the dehydration effect of a molecular sieve adsorption dehydration system meets the GB/T678-2002-absolute ethanol standard.
The heat load, operating pressure and reflux ratio of each column are shown in Table 1.
TABLE 1 Heat load, operating pressure and reflux ratio for each column
| Tower name | Degassing tower | Pre-separation tower | Ethanol tower | Methanol recovery tower | |
| Tower heat load | MKCAL/HR | 2.86 | 28.30 | 19.46 | 8.86 |
| External heating load | 2.86 | 28.30 | 0 | 0 | |
| Reflux ratio | 3.55 | 2.97 | 13.31 | 7.00 | |
| Column operating pressure | KPA | 300 | 180 | 40 | 50 |
As can be seen from Table 1, the total heat load for external application was 31.16 MKCAL/HR.
Example 2
The separation was performed by using the apparatus shown in fig. 2, and the flow rate was the same as that of example 1, wherein the dimethyl ether-to-ethanol reaction product stream S101 comprises methanol, ethanol, methyl acetate, ethyl acetate, water, propanol, dimethyl ether, etc., wherein the methanol content was 51 wt%, the ethanol content was 42 wt%, the methyl acetate and ethyl acetate content was 5 wt%, the water content was 1 wt%, the propanol content was 0.5 wt%, and the dimethyl ether content was 0.5 wt%.
The separation device comprises a rectification separation system (not shown in the figure) and a molecular sieve adsorption dehydration system A1, wherein the rectification separation system comprises a degassing tower T1, a pre-separation tower T2, an ethanol tower T3, a methanol recovery tower T4 and an ethanol recovery tower T5;
a pipeline of the dimethyl ether-to-ethanol reaction product stream S101 is connected with a feed inlet of a degassing tower T1 and is used for feeding the dimethyl ether-to-ethanol reaction product stream S101 into a degassing tower T1 for separation, a light component stream S102 is taken out of the top of the degassing tower T1, and a bottom stream S103 is taken out of the bottom of the degassing tower T1;
the pipeline of the bottom material flow S103 is connected with the feed inlet of the pre-separation tower T2 and is used for feeding the bottom material flow S103 into a pre-separation tower T2 for separation, a methanol material flow S201 containing methyl acetate and ethyl acetate is extracted from the top of the pre-separation tower T2, and an ethanol material flow S202 containing the rest methanol is extracted from the bottom of the pre-separation tower T2;
the ethanol tower T3 is a clapboard rectifying tower (packed tower), as shown in figure 3, a vertical clapboard is arranged in the clapboard rectifying tower to divide the interior of the tower into a1 st zone for feeding, a 2 nd zone for public rectification, a 3 rd zone for discharging and a 4 th zone for public stripping, a pipeline of an ethanol material flow S202 containing the rest part of methanol is connected with the 1 st zone of the ethanol tower T3, a methanol-containing material flow S301 is extracted from the 2 nd zone, a water-containing ethanol product S302 is extracted from the 3 rd zone, and a heavy component material flow S303 is extracted from the 4 th zone;
a pipeline of the methanol material flow S201 containing methyl acetate and ethyl acetate and a pipeline of the methanol material flow S301 are connected with the feed inlet of the methanol recovery tower T4 so as to be used for feeding the methanol material flow S201 containing methyl acetate and ethyl acetate and the material flow S301 containing methanol into a methanol recovery tower T4 for separation, a material flow S401 containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product S402 is extracted from the bottom of the tower;
the pipeline of the hydrous ethanol product S302 is connected with the feed inlet of a molecular sieve adsorption dehydration system A1 to obtain an anhydrous ethanol product S601 and wastewater S602, the molecular sieve dehydration system comprises evaporation, adsorption, desorption and condensation equipment, and a 3A molecular sieve is used;
a pipeline of the heavy component stream S303 is connected with a feed inlet of an ethanol recovery tower T5 and is used for feeding the heavy component stream S303 into an ethanol recovery tower T5 for separation, recovering an ethanol stream S501 from the top of the tower and recovering a heavy impurity stream S502 from the bottom of the tower;
a pipeline of the recovered ethanol stream S501 is connected with a feed inlet at the middle lower part of the ethanol tower T3 so as to be used for separating the recovered ethanol stream S501 into the ethanol tower T3 for recovering ethanol;
the top of the pre-separation tower T2 is respectively connected with reboilers E302 and E402 of an ethanol tower T3 and a methanol recovery tower T4 through pipelines so as to use steam at the top of the pre-separation tower T2 as heat sources of reboilers of an ethanol tower T3 and a methanol recovery tower T4;
a condenser E101 is arranged between the top of the degassing tower T1 and the light component stream S102, and a reboiler E102 is arranged at the bottom of the degassing tower T1;
a reboiler E202 is arranged at the bottom of the pre-separation tower T2, a condenser E301 is arranged between the top of the ethanol tower T3 and the methanol-containing material flow S301, and a condenser E401 is arranged between the top of the methanol recovery tower T4 and the material flow S401 containing methyl acetate and ethyl acetate;
a condenser E501 is provided between the top of the ethanol recovery column T5 and the recovered ethanol stream S501, and a reboiler E502 is provided at the bottom.
The separation method comprises the following steps:
(1) the dimethyl ether-to-ethanol reaction product stream S101 enters a degassing tower T1 for separation, the operating pressure of the degassing tower T1 is 300kPa, the reflux ratio is 3.55, a light component stream S102 is extracted from the top of the tower, a bottom stream S103 is extracted from the bottom of the tower, the light component stream S102 comprises light components such as dimethyl ether and the like, and the light component stream S102 returns to an upstream reaction system for continuous reaction;
(2) the bottom material flow S103 enters a pre-separation tower T2 for separation, the operating pressure of the pre-separation tower T2 is 160kPa, the reflux ratio is 2.73, a methanol material flow S201 containing methyl acetate and ethyl acetate is extracted from the top of the tower, and an ethanol material flow S202 containing the rest part of methanol is extracted from the bottom of the tower;
(3) the ethanol material flow S202 containing the residual part of the methanol enters an ethanol tower T3 for separation, the operating pressure of the ethanol tower T3 is 110kPa, the reflux ratio is 10.61, a methanol material flow S301 is extracted from a zone 2, an aqueous ethanol product S302 is extracted from a zone 3, and a heavy component material flow S303 is extracted from a zone 4;
(4) a methanol material flow S201 containing methyl acetate and ethyl acetate and a methanol material flow S301 containing methanol enter a methanol recovery tower T4 for separation, the operating pressure of the methanol recovery tower T4 is 110kPa, the reflux ratio is 7.00, a material flow S401 containing methyl acetate and ethyl acetate is extracted from the top of the tower, a methanol product S402 is extracted from the bottom of the tower, and the material flow S401 containing methyl acetate and ethyl acetate returns to an upstream reaction system for continuous reaction;
(5) the hydrous ethanol product S302 enters a molecular sieve adsorption dehydration system A1 for dehydration to obtain an anhydrous ethanol product S601 and wastewater S602;
(6) the heavy component material flow S303 enters an ethanol recovery tower T5 for separation, the operation pressure of the ethanol recovery tower T5 is 200kPa, the reflux ratio is 2.00, an ethanol material flow S501 is recovered from the top of the tower, and a heavy impurity material flow S502 is recovered from the bottom of the tower; the recovered ethanol stream S501 is passed to ethanol column T3 for further separation.
After the separation is carried out by using the separation method and the separation device, the purity of the obtained methanol product is 99.9 percent, the ethanol content in the methanol product is 80ppm, the methanol content in the hydrous ethanol product is 400ppm, the heavy alcohol content is 200ppm, the ethanol purity is 99.9 percent, and the dehydration effect of a molecular sieve adsorption dehydration system meets the GB/T678-2002-absolute ethanol standard.
The heat duty, operating pressure and reflux ratio for each column are shown in table 2.
TABLE 2 Heat load, operating pressure and reflux ratio for each column
| Tower name | Degassing tower | Pre-separation tower | Ethanol tower | Ethanol recovery tower | Methanol recovery tower | |
| Tower heat load | MKCAL/HR | 2.78 | 32.37 | 20.16 | 0.59 | 12.69 |
| External heating load | 2.78 | 32.37 | 0 | 0.59 | 0 | |
| Reflux ratio | 3.55 | 2.73 | 10.61 | 2.00 | 7.00 | |
| Column operating pressure | KPA | 300 | 260 | 110 | 200 | 110 |
As can be seen from Table 2, the total heat load for external application was 35.74MKCAL/HR
In conclusion, the separation method provided by the invention has the advantages that the obtained ethanol product and the methanol product have higher purity and good separation effect, and the separation method adopts a mode of combining a partition wall fractionation technology and a double-effect distillation technology, so that the operation energy consumption is reduced to the greatest extent, and the purpose of saving energy is achieved.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (16)
1. The separation method for preparing ethanol from dimethyl ether is characterized by comprising the following steps:
the method comprises the following steps of enabling a reaction product of the dimethyl ether and the ethanol to enter a rectification separation system to obtain a hydrous ethanol product, wherein the rectification separation system comprises a degassing tower, a pre-separation tower, an ethanol tower and a methanol recovery tower, enabling the reaction product of the dimethyl ether and the ethanol to enter the degassing tower, collecting a light component material flow from the top of the degassing tower, and collecting a tower bottom material flow from the bottom of the tower;
the tower bottom material flow enters a pre-separation tower for separation, a methanol material flow containing methyl acetate and ethyl acetate is extracted from the tower top, and an ethanol material flow containing the rest methanol is extracted from the tower bottom;
separating the ethanol material flow containing the rest methanol in an ethanol tower, extracting a water-containing ethanol product from a side line of the tower, extracting a methanol material flow from the top of the tower, and extracting a heavy component material flow from the bottom of the tower;
and the methanol material flow containing methyl acetate and ethyl acetate extracted from the top of the pre-separation tower and the methanol material flow containing methanol extracted from the top of the ethanol tower enter a methanol recovery tower to be separated, the material flow containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product is extracted from the bottom of the tower.
2. The separation method according to claim 1, wherein the rectification system further comprises an ethanol recovery tower, heavy component streams extracted from the bottom of the ethanol tower enter the ethanol recovery tower for separation, and ethanol streams are extracted from the top of the ethanol recovery tower.
3. The separation method according to claim 1 or 2, wherein the anhydrous ethanol product is obtained after the hydrous ethanol product enters a molecular sieve adsorption dehydration system.
4. A separation process according to claim 2 or claim 3, wherein the recovered ethanol stream withdrawn from the top of the ethanol recovery column is passed to an ethanol column for separation.
5. The separation process of any one of claims 1-4, wherein the dimethyl ether to ethanol reaction product comprises methanol, ethanol, methyl acetate, ethyl acetate, propanol, butanol, and dimethyl ether.
6. The separation method according to claim 5, characterized in that the mass percentage of the methanol in the reaction product of preparing ethanol from dimethyl ether is 30-70%, and the mass percentage of the ethanol in the reaction product of preparing ethanol from dimethyl ether is 30-70%.
7. The separation process according to any one of claims 2 to 6, wherein the operating pressure of the degasser is 1 to 1000kPa, the operating pressure of the pre-separator is 1 to 1000kPa, the operating pressure of the ethanol column is 1 to 1000kPa, the operating pressure of the ethanol recovery column is 1 to 1000kPa, and the operating pressure of the methanol recovery column is 1 to 1000 kPa.
8. The separation process of any one of claims 1-7, wherein the absolute ethanol product has a purity of 90-99.999%.
9. The separation process of any one of claims 1 to 8, wherein the methanol product has a purity of 85 to 99.999%.
10. The separation process according to any one of claims 1 to 9, wherein the overhead vapor of the pre-separation column is used as a heat source for reboilers of the ethanol column and the methanol recovery column.
11. A separation device for preparing ethanol from dimethyl ether, which is characterized in that,
the separation device comprises a rectification separation system, and the rectification separation system comprises a degassing tower, a pre-separation tower, an ethanol tower and a methanol recovery tower;
the pipeline of the dimethyl ether-to-ethanol reaction product material flow is connected with a feed inlet of the degassing tower so as to be used for feeding the dimethyl ether-to-ethanol reaction product material flow into the degassing tower for separation, collecting a light component material flow from the top of the degassing tower and collecting a tower bottom material flow from the bottom of the degassing tower;
the pipeline of the tower bottom material flow is connected with the feed inlet of the pre-separation tower so as to be used for feeding the tower bottom material flow into the pre-separation tower for separation, a methanol material flow containing methyl acetate and ethyl acetate is extracted from the tower top of the pre-separation tower, and an ethanol material flow containing the rest methanol is extracted from the tower bottom;
a pipeline of the ethanol material flow containing the rest part of the methanol is connected with a feed inlet of the ethanol tower, an aqueous ethanol product is extracted from a tower side line of the ethanol tower, a methanol material flow is extracted from the top of the tower, and a heavy component material flow is extracted from the bottom of the tower;
a pipeline of the methanol material flow containing methyl acetate and ethyl acetate and a pipeline of the methanol material flow containing methanol are connected with a feed inlet of the methanol recovery tower so as to be used for separating the methanol material flow containing methyl acetate and ethyl acetate and the methanol material flow containing methanol into the methanol recovery tower, the material flow containing methyl acetate and ethyl acetate is extracted from the top of the tower, and a methanol product is extracted from the bottom of the tower.
12. The separation device of claim 11,
the rectification separation system also comprises an ethanol recovery tower, and a pipeline of the heavy component material flow is connected with a feed inlet of the ethanol recovery tower so as to be used for feeding the heavy component material flow into the ethanol recovery tower for separation and recovering the ethanol material flow from the top of the tower.
13. Separation device according to claim 11 or 12,
the separation device further comprises a molecular sieve adsorption dehydration system, and the pipeline of the hydrous ethanol product is connected with the feed inlet of the molecular sieve adsorption dehydration system so as to obtain the anhydrous ethanol product.
14. Separation unit according to claim 12 or 13, wherein the line for the recovered ethanol stream is connected to the feed of the ethanol column for feeding the recovered ethanol stream to the ethanol column for separation.
15. The separation device according to any one of claims 11 to 14, wherein the ethanol column is a baffle distillation column, a vertical baffle is arranged in the baffle distillation column, a pipeline for dividing the column into a1 st zone for feeding, a 2 nd zone for public distillation, a 3 rd zone for discharging and a 4 th zone for public distillation is preferably connected with the 1 st zone of the ethanol column, a methanol-containing stream is extracted from the 2 nd zone, a water-containing ethanol product is extracted from the 3 rd zone, a heavy component stream is extracted from the 4 th zone, and a pipeline for recovering an ethanol stream is preferably connected with the 4 th zone or the 1 st zone of the ethanol column.
16. The separation device according to any one of claims 11 to 15, wherein the top of the pre-separation tower is connected with reboilers of an ethanol tower and a methanol recovery tower through pipelines respectively, so that steam at the top of the pre-separation tower is used as a heat source for the reboilers of the ethanol tower and the methanol recovery tower.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104649862A (en) * | 2015-02-05 | 2015-05-27 | 天津大学 | Method and equipment for producing ethanol product by taking ethyl acetate as raw material |
| CN105037094A (en) * | 2015-08-05 | 2015-11-11 | 安徽皖维高新材料股份有限公司 | Energy coupling distillation method for preparing ethyl alcohol by means of acetic acid ester hydrogenation |
| CN105367385A (en) * | 2014-08-27 | 2016-03-02 | 中国石油化工股份有限公司 | Separation method of making ethyl alcohol and co-production of methyl alcohol by adding hydrogen to methyl acetate |
| 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 |
| CN105837404A (en) * | 2010-02-02 | 2016-08-10 | 国际人造丝公司 | Process for purifying ethanol |
| CN106187692A (en) * | 2015-04-29 | 2016-12-07 | 中国石油化工股份有限公司 | A kind of containing ethanol with the mixed solvent of ethyl acetate |
| CN111253213A (en) * | 2018-11-30 | 2020-06-09 | 惠生工程（中国）有限公司 | Process method and system for preparing ethanol by acetate hydrogenation |
| CN111377800A (en) * | 2020-03-16 | 2020-07-07 | 中国科学院过程工程研究所 | Separation device and separation method for coal-to-ethanol liquid-phase product |
| CN111423308A (en) * | 2019-01-10 | 2020-07-17 | 惠生工程（中国）有限公司 | Product separation system and separation method for preparing ethanol by methyl acetate hydrogenation |
| CN111659150A (en) * | 2020-06-18 | 2020-09-15 | 东华工程科技股份有限公司 | Device and method for refining low-carbon alcohol by using dividing wall tower |
| CN111675601A (en) * | 2020-05-09 | 2020-09-18 | 雅邦绿色过程与新材料研究院南京有限公司 | Novel process and device for separating and purifying industrial ethanol |
| CN212662737U (en) * | 2020-05-09 | 2021-03-09 | 雅邦绿色过程与新材料研究院南京有限公司 | Bulkhead rectifying device for efficiently purifying absolute ethyl alcohol |
-
2022
- 2022-01-06 CN CN202210013961.0A patent/CN114478193B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105837404A (en) * | 2010-02-02 | 2016-08-10 | 国际人造丝公司 | Process for purifying ethanol |
| CN105367385A (en) * | 2014-08-27 | 2016-03-02 | 中国石油化工股份有限公司 | Separation method of making ethyl alcohol and co-production of methyl alcohol by adding hydrogen to methyl acetate |
| 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 |
| CN104649862A (en) * | 2015-02-05 | 2015-05-27 | 天津大学 | Method and equipment for producing ethanol product by taking ethyl acetate as raw material |
| CN106187692A (en) * | 2015-04-29 | 2016-12-07 | 中国石油化工股份有限公司 | A kind of containing ethanol with the mixed solvent of ethyl acetate |
| CN105037094A (en) * | 2015-08-05 | 2015-11-11 | 安徽皖维高新材料股份有限公司 | Energy coupling distillation method for preparing ethyl alcohol by means of acetic acid ester hydrogenation |
| CN111253213A (en) * | 2018-11-30 | 2020-06-09 | 惠生工程（中国）有限公司 | Process method and system for preparing ethanol by acetate hydrogenation |
| CN111423308A (en) * | 2019-01-10 | 2020-07-17 | 惠生工程（中国）有限公司 | Product separation system and separation method for preparing ethanol by methyl acetate hydrogenation |
| CN111377800A (en) * | 2020-03-16 | 2020-07-07 | 中国科学院过程工程研究所 | Separation device and separation method for coal-to-ethanol liquid-phase product |
| CN111675601A (en) * | 2020-05-09 | 2020-09-18 | 雅邦绿色过程与新材料研究院南京有限公司 | Novel process and device for separating and purifying industrial ethanol |
| CN212662737U (en) * | 2020-05-09 | 2021-03-09 | 雅邦绿色过程与新材料研究院南京有限公司 | Bulkhead rectifying device for efficiently purifying absolute ethyl alcohol |
| CN111659150A (en) * | 2020-06-18 | 2020-09-15 | 东华工程科技股份有限公司 | Device and method for refining low-carbon alcohol by using dividing wall tower |
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