JP5094148B2 - Method for producing allyl alcohol - Google Patents

Description

  The present invention relates to an azeotropic distillation method. More specifically, a part of the reaction raw material is supplied to the distillation step in a system having a distillation step for separating and purifying the reaction step and the reaction product, and the reaction raw material is an auxiliary for azeotropic distillation in the distillation step. The present invention relates to an azeotropic distillation method for improving separation performance of azeotropic distillation and reducing energy required for separation.

  An azeotropic phenomenon occurs in the combination of two or more components that give the maximum azeotropic point or the minimum azeotropic point. In “azeotropic distillation”, which is distillation using this azeotropic phenomenon, an azeotropic mixture is formed with one or more of these substances in a mixture of two or more substances that are difficult to separate by simple distillation or fractional distillation. When a substance to be distilled (generally called “auxiliary”) is added, the separation performance of distillation is improved. Examples of industrial fields to which azeotropic distillation is applied include a process for producing allyl alcohol by hydrolysis of allyl acetate (Patent Document 1, Patent Document 2) and a purification process for 2,3-dichloro-1-propanol (Patent Document). 3).

  Patent Document 1 discloses a method for recovering allyl acetate by an extraction operation from an azeotropic mixture of allyl acetate and water, which are one of the reaction raw material components of the hydrolysis reaction, and allyl alcohol which is a reaction product. Yes. However, in the said patent document, all the collect | recovered allyl acetate is supplied to the reaction process, and the effect at the time of supplying to a distillation column as an adjuvant is not described at all.

  Patent Document 2 discloses an azeotropic distillation method using allyl acetate, which is one of the reaction raw material components of the hydrolysis reaction, as an azeotropic aid for separation from water. However, as in Patent Document 1, this patent document does not describe any effect when allyl acetate is supplied to the distillation column as an auxiliary agent.

  On the other hand, Patent Document 3 discloses an azeotropic distillation method in which a by-product accompanying the reaction is concentrated and used as an auxiliary agent. However, since the auxiliary is not a reaction raw material, it is not recycled to the reaction process.

Hereinafter, detailed description will be given regarding each patent document.
FIG. 1 is a flowchart for explaining Patent Document 1. Referring to FIG. 1, in such a process, reaction raw material (103) obtained by mixing reaction raw material (101) mainly composed of allyl acetate and water and recovered allyl acetate (102) is subjected to a hydrolysis reactor ( 11). The reaction liquid (104) discharged from the hydrolysis reactor (11) is led to the first distillation column (12) and distilled, and a column bottom liquid (105) such as acetic acid containing water is extracted, and allyl acetate is extracted. It is circulated and supplied to the manufacturing process.

  An azeotropic distillation mixture (106) of allyl alcohol, allyl acetate, and water is distilled from the top of the first distillation column (12) and introduced into the decanter (13). In the decanter (13), the mixture (106) is separated into two layers, an oil layer (110) rich in allyl acetate and an aqueous layer (109) low in allyl acetate. The oil layer (110) is introduced into the extraction tower (14). In this extraction tower (14), allyl acetate is removed by an extraction operation using an extractant (112) mainly composed of water, and the bottom liquid (111) is composed mainly of allyl alcohol and water. In operation, hydrated allyl alcohol is purified. On the other hand, a liquid (113) containing allyl acetate substantially free of allyl alcohol and water is extracted from the top of the extraction tower (14) and sent to the reactor (11) as the circulating liquid (102). It is done.

  FIG. 2 is a flowchart for explaining Patent Document 2. The reaction raw material liquid (201) mainly composed of allyl acetate and water and the recovered liquid (202) containing the reaction raw material components of water and allyl acetate are combined and passed through the hydrolysis reactor (21) to thereby prepare allyl acetate. Allyl alcohol and acetic acid are obtained by hydrolysis reaction. The reaction product liquid (204) generated in the reactor (21) is composed of allyl acetate, allyl alcohol, water and acetic acid, and is supplied to the first distillation column (22). , An unreacted allyl acetate is recovered as an azeotrope of allyl acetate, water and allyl alcohol, and the distillate (208) is circulated to the hydrolysis reactor (21).

  On the other hand, the produced acetic acid, allyl alcohol and unreacted water, and a part of allyl acetate are extracted from the bottom of the first distillation column (22). The liquid (205) withdrawn from the bottom of the first distillation column (22) is supplied to the second distillation column (23), and allyl acetate in the liquid (205) is used as an azeotropic auxiliary agent. To obtain an azeotropic mixture (212) of allyl alcohol, water and allyl acetate, and a liquid (209) containing acetic acid, acetic acid and water as main components from the bottom of the column. The top fraction (212) of the second distillation column (23) is supplied to the third distillation column (24).

  Water, allyl acetate, and allyl alcohol are distilled from the top of the third distillation column (24). And after condensation, it is divided into two layers of an oil layer and an aqueous layer by a decanter (25). The oil layer is mainly composed of allyl acetate, and allyl alcohol is purified by refluxing the whole or a part of this organic phase to the column (24) as an azeotropic auxiliary. The aqueous layer contains a small amount of allyl alcohol and allyl acetate and is returned to the hydrolysis reactor (21) together with a portion of the oil layer.

  FIG. 3 is a flowchart for explaining Patent Document 3. An intermediate product 2,3-dichloro-1-propanol (hereinafter abbreviated as DCH) in the epichlorohydrin production process using allyl alcohol as a reaction raw material, and 1,2,3-trichloropropane (hereinafter referred to as a by-product) as a by-product. (Hereinafter abbreviated as TCP) and other liquid (301) containing a low boiling point component are supplied to the first distillation column (31), and TCP is used as an auxiliary agent from the top of the first distillation column (31). The liquid (307) to be supplied is supplied. The water in the liquid (301) distills to the top of the tower as a TCP-water azeotrope having a lower boiling point than the DCH-water azeotrope, because the TCP supplied from the top acts as an auxiliary agent. This is the top distillate (303) of the first distillation column (31). Therefore, since most of the water is distilled in the form of a TCP-water azeotrope, distillation of DCH to the top of the column is suppressed. The column bottom liquid (302) is supplied to a purification facility in a subsequent process. The column top distillate (303) is condensed and cooled, and separated into an aqueous layer (304) and an oil layer (305) by a decanter (32). The aqueous layer (304) is sent to a separate processing facility. The oil layer (305) is supplied to the second distillation column (33), and is supplied from the bottom of the column to the first distillation column (31) as a liquid (307) mainly composed of TCP. The column top distillate (306) is introduced into a separate processing facility.

  In recent years, there has been a strong demand to reduce the energy required for separation without substantially reducing the separation performance in azeotropic distillation from the viewpoint of reducing carbon dioxide emissions and saving fuel.

Japanese Patent Laid-Open No. 62-149637 JP-A-1-85940 Japanese Unexamined Patent Publication No. 7-25796

  An object of the present invention is to provide an azeotropic distillation method that makes it possible to reduce the energy required for separation without substantially reducing the separation performance in azeotropic distillation.

  As a result of diligent research, the present inventors have supplied a part of the reaction raw material components in the reaction process to the distillation process, and positively use them as an azeotropic auxiliary, rather, the distillation process of the reaction raw material in the reaction process. It has been found that the separation performance can be improved and energy can be reduced overall.

  The azeotropic distillation method of the present invention is based on the above knowledge. More specifically, the azeotropic distillation method includes at least a reaction step, a distillation step for separating and purifying reaction products, and a step of recovering a reaction raw material in a subsequent step of the distillation step. In the azeotropic distillation method, at least one of the reaction raw materials in the reaction step acts as an azeotropic distillation auxiliary in the distillation step; and a part of the reaction raw material acting as the auxiliary goes to the distillation step It is characterized by supplying.

  In the azeotropic distillation method of the present invention having the above-described configuration, a merit that separation performance of azeotropic distillation is improved is obtained by supplying a part of the reaction raw material to the distillation step as an azeotropic auxiliary. In this case, there may be a disadvantage associated with an increase in the circulation rate of the unreacted raw material. However, such a disadvantage is substantially due to a decrease in mixing of high-boiling components in the distillate, a reduction in drainage load, etc. It has been found by the inventors that this is not a problem.

  In the present invention, when the reaction raw material also acts as an azeotropic auxiliary, by supplying at least a part of the reaction raw material to the distillation step as an azeotropic auxiliary (without supplying it to the reaction system), the distillation step The separation performance is improved and the energy required in the distillation process can be reduced.

  The present invention includes, for example, the following aspects [1] to [5].

  [1] An azeotropic distillation method comprising at least a reaction step, a distillation step for separating and purifying reaction products, and a step of recovering a reaction raw material after the distillation step;

  At least one of the reaction raw materials in the reaction step acts as an azeotropic distillation aid in the distillation step; and supplies a part of the reaction raw material acting as the aid to the distillation step. A characteristic azeotropic distillation method.

  [2] A part of a liquid and / or gas recovered in a subsequent step of the distillation step and containing 80% by mass or more of a reaction raw material that acts as an unreacted auxiliary agent is supplied to the distillation step. The azeotropic distillation method according to [1].

  [3] The distillation step comprises a plurality of distillation columns, and a part of the liquid and / or gas containing 80% by mass or more of the reaction raw material acting as an unreacted auxiliary agent is supplied to the first distillation column. The azeotropic distillation method according to [2], which is characterized.

  [4] The azeotropic distillation method according to any one of [1] to [3], wherein the reaction raw material acting as an auxiliary is allyl acetate and the reaction product is allyl alcohol and acetic acid. .

  [5] A method for producing allyl alcohol, comprising the azeotropic distillation method described in [4] as a part of the process.

  As described above, according to the present invention, as a result of improving the separation performance of azeotropic distillation, it is possible to achieve reduction of energy consumption of the distillation step and reduction of high boiling point component concentration in the top fraction in the distillation step. .

  Hereinafter, the present invention will be described in more detail.

(Azeotropic distillation method)
The azeotropic distillation method of the present invention includes a reaction step, a distillation step for separating and purifying reaction products, and a step of recovering reaction raw materials in a subsequent step of the distillation step. The present invention is characterized in that a part of the reaction raw material is supplied to the distillation step in a system in which at least one of the reaction raw materials serves as an azeotropic distillation aid in the distillation step.

(Azeotropic)
An azeotropic phenomenon occurs in a combination (azeotropic mixture) of at least two components that gives a maximum azeotropic point or a minimum azeotropic point (collectively referred to as “azeotropic point”). The composition of the vapor is equal to the composition of the liquid. In the present invention, azeotropic distillation is carried out utilizing such an azeotropic phenomenon.

(Combination giving an azeotrope)
In the present invention, the combination of components giving an azeotrope is not particularly limited in the present invention as long as at least one of the reaction raw materials is a system that serves as an azeotropic distillation aid in the distillation step. For example, combinations of the components shown below can be preferably used.

(1) Water-allyl acetate-allyl alcohol

(Auxiliary)
When a substance that forms an azeotrope with one or more of these components is added to a mixture of two or more substances that are difficult to separate by simple distillation or fractional distillation, the separation performance of the distillation is improved. Such components are called “auxiliaries” (sometimes called azeotropic agents or entrainers). In the present invention, at least one of the reaction raw materials serves as an azeotropic distillation aid in the distillation step. The criteria for determining whether or not to become an auxiliary agent is determined by whether or not the azeotropic point approaches the highest or lowest azeotropic composition by adding any of the azeotropic components.

(One embodiment of the present invention)
FIG. 4 is a flowchart illustrating one embodiment of the present invention. In FIG. 4, the liquid (401) containing the reaction raw material is joined with the circulating liquid (402) made of the reaction raw material recovered from the reaction raw material recovery step (44) described later, and the reaction step (41) is obtained as the reaction raw material (403). To be supplied. The reaction product liquid (404) output from the reaction step (41) joins with the liquid (420) containing the reaction raw material that acts as an azeotropic auxiliary agent, and is supplied to the azeotropic distillation tower (42).

  The reaction product liquid (404) supplied to the azeotropic distillation tower (42) is subjected to a distillation operation to extract a bottom liquid (405) mainly containing high-boiling components from the tower bottom, and a co-polymer containing an auxiliary agent from the tower top. An overhead fraction (406) comprising a boiling mixture is withdrawn. A part of the column top fraction (406) is returned to the azeotropic distillation column (42) as reflux (407), and the remaining liquid (408) is supplied to the reaction raw material recovery step (44). The reaction raw material recovery step (44) is not limited to distillation and extraction as long as the reaction raw material can be recovered, but any separation operation can be used. What is necessary is just to determine an appropriate separation operation. The reaction raw material (410) recovered from the reaction raw material recovery step (44) is supplied to the reaction step (41) as (402).

  The addition position of the liquid (420) containing the reaction raw material is not limited to the position of the reaction product liquid (404), and may be added to the reflux (407), for example. The liquid (420) containing the reaction raw material may be at least a part of the circulating liquid (410) made of the recovered reaction raw material or a part of the reaction raw material component to be newly added.

  In the liquid (420) containing the reaction raw material, the concentration of the reaction raw material acting as an auxiliary agent is preferably 80% by mass or more, and more preferably 90% by mass or more. When the concentration is less than 80% by mass, the tendency to increase the supply amount of the reaction raw material (420) in order to obtain a suitable azeotropic composition increases, and as a result, the energy cost tends to increase due to an increase in the load on the reboiler. there is a possibility.

(Addition of azeotropic auxiliary)
Whether or not to add the liquid (420) to be supplied to the azeotropic distillation column (42) as an azeotropic auxiliary and the amount of addition may be determined based on the following criteria (I) to (II).

  (I) The merit by the efficiency improvement of an azeotropic distillation tower (42) exceeds the demerit in a reaction raw material collection | recovery process (44).

  The merit is an economic effect brought about by an improvement in the separation performance of the azeotropic distillation column (42). In general, in the distillation operation, the reflux operation is performed in order to reduce the high boiling point concentration in the top fraction of the column. Therefore, the reboiler (43) of the azeotropic distillation column (42) is required by the amount supplied to the distillation column as the reflux. Energy increases. However, since the composition of the top distillate (406) approaches the azeotropic composition having the lowest boiling point by the practice of the invention, the predetermined separation performance can be satisfied with less reflux, so that the azeotropic distillation tower (42) The reboiler (43) can reduce the required energy. Alternatively, since the amount of high-boiling components flowing out from the top of the column is reduced due to the decrease in the high-boiling point concentration, the processing cost in the subsequent process is reduced.

  On the other hand, the above demerit is economical because the amount of unreacted reaction raw material circulated increases by the amount used as an auxiliary agent and the processing amount in the reaction raw material recovery step (44) increases. It is disadvantageous to.

  (II) Observe other restrictions such as operating conditions. Since the operating conditions vary depending on the target compound and equipment to be produced, it is determined by restrictions on target values such as the flow rate and composition of either or both of the top and bottom extracted liquids.

  For example, in the specific example of Example 1 described later, the amount of heating steam used in the recovery process of the extractant used in the subsequent process (the same extraction process described in Patent Document 1) is 0.2 mass / hour. However, the flow rate of acetic acid in the wastewater decreased by 0.04 parts by mass per hour by greatly reducing the concentration of acetic acid (high boiling component) at the azeotropic tower / top. Therefore, in the case of the first embodiment, the following inequality is established.

Advantages of 0.04 parts by mass of acetic acid (wastewater treatment costs / acetic acid loss) per hour (approximately 10 million yen per year)> Disadvantages of increasing steam by 0.2 parts by mass per hour (approximately 2 million yen per year)

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1
As an example, the present invention was carried out in the allyl alcohol production process of Patent Document 1.
CH ₃ COOCH ₂ CH═CH ₂ + H ₂ O → CH ₂ = CHCH ₂ OH + CH ₃ COOH

Hereinafter, description will be made with reference to FIG. 5 which is a flowchart for explaining the first embodiment.
In FIG. 5, the reaction raw material (501) containing allyl acetate produced | generated through the allyl acetate synthetic | combination process is mixed with the reaction raw material allyl acetate (502) collect | recovered by the extraction tower (55) mentioned later, and a hydrolysis reactor (51 ).

  In the hydrolysis reaction (51), a strongly acidic ion exchange resin was used as a catalyst, and the reaction was performed under the temperature conditions of 0.6 MPa and 78 ° C. with a residence time of 50 minutes. A stream (505) obtained by mixing the reaction product liquid (504) and a part (520) of allyl acetate recovered by the extraction tower (55) is supplied to the distillation tower (52). The distillation column is operated under conditions of a pressure of 0.15 MPa, a column top temperature of about 90 ° C., and a column bottom temperature of about 115 ° C. The liquid (506) withdrawn from the bottom of the column is a liquid mainly composed of acetic acid and water, and is returned to the allyl acetate synthesis step for recycling. The distillate (507) from the top of the column is cooled to around 50 ° C. and supplied to the decanter (54). In the decanter (54), the oil layer having a high allyl acetate concentration and the water layer having a low allyl acetate concentration are separated into two layers. A part of the oil layer liquid is returned as reflux (509) to improve the separation performance of the azeotropic distillation column (52), and the remaining oil layer liquid (510) is supplied to the extraction column (55).

  On the other hand, the aqueous layer (508) is supplied to the allyl alcohol purification step together with the liquid (512) described later. In the extraction column (55), under the conditions of 0.110 MPa and 40 ° C., the countercurrent contact between the liquid (510) extracted from the top of the azeotropic distillation column (52) and the liquid (511) consisting essentially of water (510 mass) (Flow rate) :( 511 mass flow rate) = 1: 1.4 The allyl acetate (513) from which allyl alcohol has been removed is extracted from the top of the column, and allyl alcohol slightly containing allyl acetate is extracted from the bottom of the column. The aqueous solution (512) is withdrawn. (508) and (512) are mixed, and after allyl acetate is removed in the next distillation tower, an azeotropic composition of allyl alcohol and water is obtained from the top of the tower by distillation of the allyl alcohol aqueous solution. The recovered allyl acetate (513) (concentration 97.3%) is recycled as a reaction raw material (502) of the hydrolysis reactor (51) and an azeotropic distillation auxiliary (520).

  Here, the operating conditions of (51) and (54) are as described above, the bottom extraction of (52) (506) the flow rate is 62.9 parts by mass per hour, and the reflux from the oil layer of the decanter (54) (509) The test was conducted for 8 hours under an operating policy in which the flow rate was constant at 52.5 parts by mass per hour. Table 1 shows the average flow rate and composition of each flow. At this time, the top temperature of the distillation column (52) was 92.7 ° C., and the amount of steam used in the reboiler (53) was 38.3 parts by mass. Moreover, the production amount of allyl alcohol (transfer amount to the next step: (508) + (512)) was 12.4 parts by mass per hour.

  Table 1 shows the flow rate / composition data of each flow of Example 1 at this time.

(Example 2)
A flow (flow diagram) for explaining the second embodiment is shown in FIG. 6 (in the description of FIG. 6, the same portions as those in FIG. 5 are denoted by the same reference numerals and the description thereof is omitted).

  In FIG. 6, allyl acetate recovered from the extraction column as in the flow (521) is supplied to the reflux (509) of the azeotropic distillation column (52), and the sum of the flow rates of (509) and (521) is obtained in the first embodiment. The experiment was conducted under the same conditions as in Example 1 with respect to the operating conditions of (51) and (54) and the flow rate of the bottom extraction (506) of the azeotropic distillation column (52), except that the values were the same as those in Example 1. did. At this time, the top temperature of the distillation column (52) was 92.2 ° C., and the amount of steam used in the reboiler (53) was 37.3 parts by mass per hour. Moreover, the production amount of allyl alcohol (transfer amount to the next step: (508) + (512)) was 12.4 parts by mass per hour.

  Table 2 shows the flow rate / composition data of each flow of Example 2 at this time.

(Comparative Example 1)
A flow (flow diagram) for explaining the first comparative example is shown in FIG. 7 (in the explanation of FIG. 7, the same portions as those in FIG. 5 are denoted by the same reference numerals and the explanation thereof is omitted).

  In FIG. 7, under the condition that the reaction raw material is not added as an auxiliary agent (that is, the flow rate of the stream (520) in FIG. 5 is 0), reflux (509) is performed in order to suppress the acetic acid concentration in the column top fraction. The experiment was carried out under the same conditions as in Example 1 with respect to the operating conditions of (51) and (54) and the flow rate of (506) except that the flow rate was increased to 54.9 parts by mass per hour. At this time, the top temperature of the distillation column (52) was 93.2 ° C., and the amount of steam used in the reboiler (53) was 41.2 parts by mass. Moreover, the production amount of allyl alcohol (transfer amount to the next step: (508) + (512)) was 12.4 parts by mass per hour.

  Table 3 shows the flow rate / composition data of each flow in Comparative Example 1 at this time.

  As described above, in Examples 1 and 2 and Comparative Example 1, the amount of allyl alcohol produced is almost the same, but in Examples 1 and 2, it is possible to reduce the amount of steam used in the reboiler (53). It was.

(Example 3)
In the same manner as in Example 1, allyl acetate (concentration 97.3%) recovered from the extraction column as in the flow (520) was used as an azeotropic agent in the azeotropic distillation column (52) of the hydrolysis reactor (51). The operation of supplying to the outlet (504) was carried out for 223 days. The average production during the period was 100.0 parts by mass per hour.

  The top temperature of (52) was 91.4 ° C., the bottom temperature was 116.9 ° C., the pressure was 0.110 MPa, and the top pressure of (55) was 0.110 MPa. The average amount of steam used in (53) was 316 parts by mass per hour, and the average amount of steam used including the post-process was 356 parts by mass per hour. Of the acetic acid that flowed into (52), the recovery rate of acetic acid from the bottom of (52) tower was 99.9%.

Table 4 shows the flow rate / composition data of each flow during the operation.

(Comparative Example 2)
In the same manner as in Comparative Example 1, the operation for setting the flow rate of the flow (520) in FIG. 5 to 0 was performed for 167 days. The average production during the period was 108.8 parts by mass per hour.

  The top temperature of (52) was 92.0 ° C., the bottom temperature was 117.4 ° C., the pressure was 0.112 MPa, and the top pressure of (55) was 0.112 MPa. The average amount of steam used in (53) was 375 parts by mass per hour, and the average amount of steam used including the post-process was 464 parts by mass per hour. Of the acetic acid flowing into (52), the recovery rate of acetic acid from (52) the bottom of the column was 99.6%.

Table 5 shows the flow rate / composition data of each flow during operation.

FIG. 10 is a flowchart (or block diagram) for explaining a process flow of Patent Document 1. 10 is a flowchart for explaining a process flow of Patent Document 2. FIG. FIG. 10 is a flowchart for explaining a process flow of Patent Document 3. It is a flowchart for demonstrating the process flow of this invention. FIG. 5 is a flowchart for explaining a process flow of Examples 1 and 3. FIG. 6 is a flowchart for explaining a process flow of the second embodiment. It is a flowchart for demonstrating the process flow of the comparative examples 1 and 2. FIG.

Explanation of symbols

11 Hydrolysis reactor 12 Distillation tower 13 Decanter 14 Extraction tower

21 Hydrolysis reactor 22 First distillation column 23 Second distillation column 24 Third distillation column 25 Decanter

31 First distillation column 32 Decanter 33 Second distillation column

41 reaction process 42 azeotropic distillation tower 43 azeotropic distillation tower (42) reboiler 44 reaction raw material recovery process

51 Hydrolysis reactor 52 Azeotropic distillation tower 53 Azeotropic distillation tower (52) Reboiler 54 Decanter 55 Extraction tower

101 Hydrolysis reaction raw material liquid 102 Recovered reaction raw material liquid 103 Liquid supplied to hydrolysis reactor (11) 104 Reaction product liquid of hydrolysis reactor (11) 105 First distillation column (12) Column bottom extraction liquid 106 First distillation column (12) Top steam 107 First distillation column (12) Reflux liquid 108 Decanter (13) Oil layer extraction liquid 109 Decanter (13) Aqueous layer extraction liquid 110 Extraction tower (14) Extraction water 111 Extraction tower (14 ) Extraction liquid 112 Extraction tower (14) Extraction residual liquid

201 Hydrolysis reaction raw material liquid 202 Recovered reaction raw material liquid 203 Liquid supplied to hydrolysis reactor (21) 204 Reaction product liquid of hydrolysis reactor (21) 205 First distillation column (22) Column bottom extraction liquid 206 First distillation column (22) Top vapor 207 First distillation column (22) Refluxing liquid 208 First distillation column (22) Distillate 209 Second distillation column (23) Bottom extract liquid 210 Second distillation column (23 ) Column top vapor 211 Second distillation column (23) Reflux liquid 212 Second distillation column (23) Distillate 213 Third distillation column (24) Column bottom extraction liquid 214 Third distillation column (24) Column top vapor 215 Three distillation column (24) reflux liquid 216 decanter (25) water layer extraction liquid 217 decanter (26) oil layer extraction liquid

301 First Distillation Tower (31) Feed Liquid 302 First Distillation Tower (31) Bottom Extract Liquid 303 First Distillation Tower (31) Top Steam 304 Decanter (32) Water Layer Extraction Liquid 305 Decanter (32) Oil Layer Extraction Liquid 306 Second distillation column (33) distillate 307 Auxiliary liquid recovered from second distillation column (33)

401 reaction raw material liquid 402 recovered unreacted raw material liquid 403 liquid supplied to reaction step (41) 404 reaction product liquid in reaction step (41) 405 azeotropic distillation tower (42) bottom extract liquid 406 azeotropic distillation tower ( 42) Top vapor 407 Azeotropic distillation tower (42) Reflux liquid 408 Azeotropic distillation tower (42) Distillate 409 Residual liquid after recovering unreacted raw material from reaction raw material recovery step (44) 410 Reaction raw material recovery step Unreacted raw material liquid recovered from (44) 420 Reactive raw material liquid supplied to azeotropic distillation tower (42) as an auxiliary agent

501 Hydrolysis reaction raw material liquid 502 Recovered reaction raw material liquid 503 Liquid supplied to hydrolysis reactor (51) 504 Reaction product liquid of hydrolysis reactor (51) 505 Azeotropic distillation tower (52) Feed liquid 506 Azeotropic Distillation tower (52) Bottom extract liquid 507 Azeotropic distillation tower (52) Top vapor 508 Decanter (54) Water layer extraction liquid 509 Azeotropic distillation tower (52) Reflux liquid 510 Decanter (54) Oil layer extraction liquid 511 Extraction tower (55) Extraction water 512 Extraction tower (55) Extraction liquid 513 Extraction tower (55) Extraction residual liquid 514 Acetic acid recovered from high boiling waste liquid 515 Allyl acetate recovered from the next step 520 (51) reaction product liquid (504) Recovery reaction raw material liquid to be added 521 Recovery reaction raw material liquid to be added to reflux liquid (509) of azeotropic distillation column (52)

Claims (2)

A method for producing allyl alcohol comprising at least an allyl acetate hydrolysis reaction step, a distillation step for separating and purifying allyl acetate and allyl alcohol , and an extraction step for recovering allyl acetate from the liquid distilled from the top of the distillation step. Te, was recovered in the extraction step, a portion of the liquid and / or gas allyl acetate containing not less than 90 mass% as an azeotropic aid supplied to the distillation step, and carrying out azeotropic distillation allyl A method for producing alcohol . The distillation step comprises a plurality of distillation columns, and a part of the liquid and / or gas containing 90% by mass or more of allyl acetate as the azeotropic aid is supplied to the first distillation column. The manufacturing method of allyl alcohol as described in any one of.

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