WO2006008996A1

WO2006008996A1 - Methods of distilling ethanol and distillation apparatus

Info

Publication number: WO2006008996A1
Application number: PCT/JP2005/012750
Authority: WO
Inventors: Shizuo Midori; Koji Hisamura; Yurie Ookuma; Ryoji Fujita; Syuroku Suzuki
Original assignee: Kyowa Hakko Chemical Co., Ltd.; Kyowa Hakko Kogyo Co., Ltd.
Priority date: 2004-07-23
Filing date: 2005-07-11
Publication date: 2006-01-26
Also published as: JP2006036659A

Abstract

Methods of ethanol distillation in which the energy to be consumed can be diminished, the distillation apparatus to be used can be miniaturized, and the cost of the distillation apparatus and the cost of ethanol distillation can be reduced. Purified ethanol can be obtained from crude ethanol. In one distillation method, distillation columns are employed which comprise a first column extending downward from the column top, a second column located adjacently to the first column through a partition, and a third column extending upward from the column bottom and connected to the first and second columns. Preferably, the disposition of these three distillation columns suffices, and the disposition of accessory devices and measures for the three series suffices. Thus, not only the energy to be consumed can be diminished, but the distillation apparatus can be miniaturized. The cost of the distillation apparatus and the cost of ethanol distillation can be reduced.

Description

Ethanol distillation method and distillation apparatus

Technical field

The present invention relates to an ethanol distillation method and distillation apparatus.

Background art

Conventionally, crude ethanol containing at least a trace amount of low-boiling components, methanol, fusel oil (generic name for propanol, butanol, amino alcohol, etc.) components by distillation, etc., refined ethanol for beverages or industrial use, That is, when obtaining purified ethanol, for example, a distillation apparatus in which six distillation columns are combined is used, and heating and cooling are repeated in each distillation column.

FIG. 1 is a diagram showing an example of a conventional distillation apparatus.

[0004] In the figure, 11 is a 50-stage extractive distillation tower, 12 is a 50-stage rectification tower, 13 is a 15-stage dehydration tower, 14 is a 49-stage purification tower, 15 is a 59-stage demethanol tower, 16 is a 55-stage vacuum distillation column. The extractive distillation column 11, the rectifying column 12, the dehydrating column 13, the purification column 14, the demethanol column 15 and the vacuum distillation column 16 are all distillation columns having a plate column force, and the number of plates is reduced by the actual number of plates. It is counted.

[0005] Crude ethanol M (95% by volume [vol%]) containing a small amount of low-boiling components, methanol, fusel oil components and the like is supplied to the upper 35 stages of the extractive distillation column 11. The hot water W, which is hot water, is supplied to the top of the extractive distillation column 11. The extractive distillation column 11 is heated by blowing steam S into the bottom of the column.

[0006] The vapor VI discharged from the top of the extractive distillation column 11 is condensed by the condensers Hl and H2 to become a distillate containing a small amount of a low boiling point component and a part of the fusel oil component. A part of the distillate is returned to the top of extractive distillation column 11 via storage tank R2, and the rest is discharged.

[0007] The bottoms from which the bottom force of the extractive distillation column 11 has also been discharged has an ethanol concentration of about 15 [vol%], and is supplied to the top of the destillation and purification column 13. The vapor discharged from the top of the destilling tower 13 has an ethanol concentration of about 50 vol%, and is supplied to the bottom of the rectifying tower 12 for the purification. The bottoms discharged from the bottom of the distillation column 12 is supplied to the top of the desulfurization tower 13.

[0008] Further, the hot water discharged from the bottom of the destilling tower 13 is circulated and supplied to the top of the extractive distillation tower 11 as split hot water W via the storage tank R1, and the excess hot water is Discharged. Dehydration The heating of the precision tower 13 is performed by blowing steam S into the bottom of the tower.

[0009] The vapor V2 from which the top force of the rectifying column 12 has also been discharged is condensed by the condensers H3 and H4 to become a distillate containing methanol, and a part of the distillate is a rectification column. It is refluxed to the top of 12 columns, and the remainder is fed to the demethanol tower 15.

[0010] The ethanol fraction from which trace amounts of low-boiling components, methanol, fusel oil components, and the like have been substantially removed is discharged as a side stream by the 48-stage force of the rectifying column 12. The fusel oil component is concentrated at the bottom of the rectifying column 12, extracted from the fourth stage, and supplied to the storage tank R4.

[0011] The ethanol fraction discharged from the rectification column 12 is supplied to the 33rd stage of the purification column 14 at an ethanol concentration of about 96 [vol%]. The vapor V3 discharged from the top of the purification tower 14 is condensed by the condensers H5 and H6 to become a distillate containing methanol, and a part of the distillate is at the top of the purification tower 14. The mixture is refluxed, and the remainder is supplied to the demethanol tower 15. Then, the bottoms from the bottom of the purification tower 14 are discharged as purified ethanol (alcohol) having an ethanol concentration of about 96 vol% and as a product.

[0012] A part of the bottoms is heated to become steam and is circulated to the purification tower 14 by reboilers Ml and M2. The purification tower 14 is heated by reboilers Ml and M2.

[0013] The distillate from the rectification tower 12 is in the 25th stage of the demethanol tower 15, the distillate in the purification tower 14 is in the 33rd stage in the demethanol tower 15, and the distillate in the vacuum distillation tower 16 is the storage tank. It is supplied to 25 stages of the demethanol tower 15 via R3. Further, the vapor V4 discharged from the top of the demethanol tower 15 is condensed by the condensers H7 and H8 to become a distillate containing methanol, and a part of the distillate is removed from the demethanol tower 15. Is returned to the top of the tower and the rest is discharged as methylon. The bottoms discharged from the bottom of the methanol removal tower 15 is supplied to the storage tank R2, and a part of the liquid discharged from the storage tank R2 is supplied to the top of the extractive distillation tower 11, Is supplied to storage tank R4. The demethanol tower 15 is heated by blowing steam S into the bottom of the tower.

[0014] The liquid in the storage tank R4 is supplied to the 23rd stage of the vacuum distillation column 16. The vacuum distillation tower 1 The vapor V5 discharged from the top of column 6 is condensed by condensers H9 and H10 to become a distillate, and a part of the distillate is refluxed to the top of the vacuum distillation column 16 and remains. Is supplied to storage tank R3. The fusel oil component in the vacuum distillation column 16 is concentrated and discharged as a side stream of 19 stages. Then, hot water is discharged from the bottom of the vacuum distillation column 16. Heating of the vacuum distillation column 16 is performed by a reboiler M3.

[0015] Thus, the process of the conventional ethanol distillation method for obtaining purified ethanol from crude ethanol M comprises 6 distillation columns. In the material balance of the entire process, crude ethanol M was extracted.

Steam S is supplied directly to the bottom of each of the extractive distillation column 11, the destillation and purification column 13, and the demethanol column 15. The hot water from the bottom of the desulfurization tower 13, the bottom power of the purification tower 14 and purified ethanol, the top power of the demethanol tower 15 and the methylon force, and the fusel oil component from the side of the vacuum distillation tower 16 are decompressed. tower underlying strength of the distillation column 16 also hot water is discharged (for example, see Patent documents 1 and 2.) ₀

Patent Document 1: Japanese Patent Laid-Open No. 10-57703

Patent Document 2: Japanese Patent Laid-Open No. 10-57704

Disclosure of the invention

Problems to be solved by the invention

However, in the conventional ethanol distillation method, the extractive distillation column 11, the rectifying column 12, the desulfurization column 13, the purification column 14, the demethanol column 15, and the vacuum distillation column 16 have six groups. This distillation column is installed and it is necessary to repeat heating and cooling in each distillation column. Therefore, it is necessary to install condensers H1 to H10, reboilers M1 to M3, pumps and other auxiliary equipment and instrumentation. It is necessary to arrange for the series. Therefore, the distillation apparatus becomes larger as the consumed energy increases, and the cost of the distillation apparatus and the cost for distilling ethanol increase.

[0017] The present invention solves the problems of the conventional ethanol distillation methods, can reduce the energy consumed, can reduce the size of the distillation apparatus, and can reduce the cost of the distillation apparatus, It is another object of the present invention to provide an ethanol distillation method and distillation apparatus that can reduce the cost for distilling ethanol. Means for solving the problem

[0018] Therefore, in the ethanol distillation method of the present invention, a crude ethanol having a refined ethanol power is also obtained. The crude ethanol includes methanol, propanol, isopropyl alcohol, water, fusel oil, aldehyde, acetone and the like, and the purity of ethanol is preferably 93% or less.

[0019] In one distillation method, a first column formed with a column top force directed downward, a second column formed adjacent to the first column via a medium cut, and a column A distillation column having a third column formed from the bottom to the top and communicating with the first and second columns is used.

In another ethanol distillation method of the present invention, the distillation column is a first distillation column. Then, in the first distillation column, crude ethanol is supplied to the middle part of the first column, the bottom water of the third column is refluxed to the top of the first column, and surplus Then, the steam discharged from the tops of the first and second columns is condensed into a distillate, and a part of each distillate is divided into the first and second distillates, respectively. Circulates to the second column, discharges the remainder of the distillate, discharges the ethanol fraction as an intermediate force side stream of the second column, and concentrates it as a lower force side stream of the second column. Drain the components and heat the third column by blowing steam into the bottom of the column, and if necessary, heat the first column by blowing steam at the bottom.

[0021] In still another ethanol distillation method of the present invention, a small amount of low-boiling components and fusel obtained from an ethanol fraction obtained as an intermediate force side stream of the second column of the first distillation column or in ethanol distillation. The oil component is removed and purified ethanol can be obtained from the ethanol fraction in which methanol remains.

[0022] Then, the first column formed with the tower bottom force also directed upward, and the first column through the partition.

A second distillation column having a second column formed adjacent to the column and a third column formed downward from the top of the column and communicating with the first and second columns is used. .

[0023] In still another ethanol distillation method of the present invention, in the second distillation column, the ethanol fraction is supplied to an intermediate portion of the first column, and the first distillation column No. 2 The distillate from this column and the distillate from the third distillation column are fed to the middle part of the second column, and the vapor discharged from the top of the column is condensed into a distillate. A part is refluxed as a reflux liquid to the third column, the remainder of the distillate is discharged, the reflux liquid is distributed to the first and second columns, and the bottom force of the first column is discharged. A portion of the resulting bottoms is vaporized and circulated to the first column, the remainder of the bottoms is discharged as purified ethanol, and the bottom of the second column is discharged. A portion of the liquid is circulated to the top of the first column of the first distillation column, and the remainder of the bottom is supplied to the middle portion of the third distillation column to heat the first column. Is performed by exchanging heat with the vapor discharged from the top column of the first column of the first distillation column by a reboiler, and a shortage of heat. Compensated by blowing steam through another reboiler, the heating of the second column is carried out by blowing steam into the bottom.

[0024] In still another ethanol distillation method of the present invention, in the third distillation column further comprising a concentrating unit and a recovery unit without partitioning, the distillation in the first column of the first distillation column is performed. A part of the effluent, a concentrated fusel oil component discharged as a side stream from the lower part of the second column of the first distillation column, and a bottom effluent of the second column of the second distillation column Is operated under reduced pressure to condense the vapor discharged from the top of the column into a distillate, and a part of the distillate is refluxed to the concentrating section as a reflux liquid, and the remainder of the distillate is returned to the 2 is fed to the middle part of the second column of the distillation column 2, and as a side stream from the middle part of the recovery part, the concentrated fusel oil component is discharged, and a portion of the hot water discharged from the bottom of the tower is recycled. The tower top force of the second column of the first distillation tower is heated by exchanging heat with the discharged steam, Was circulated through the collecting section Te, it discharges the remaining hot water.

[0025] In still another ethanol distillation method of the present invention, the first to third distillation columns are further operated in order.

[0026] In yet another ethanol distillation method of the present invention, crude ethanol-purified ethanol is obtained.

[0027] Then, ethanol is purified and methanol is separated by the first distillation column, purification column and demethanol tower, and the fusel oil component is concentrated and separated by the third distillation column.

[0028] In still another ethanol distillation method of the present invention, a general ethanol steam is further added. A small amount of low boiling point components and fusel oil components are removed by distillation, and ethanol fractions from which methanol remains remain are purified by ethanol purification, methanol separation and fusel oil component separation by second and third distillation columns. I do.

[0029] In still another ethanol distillation method of the present invention, each of the columns is filled with a regular packed product or an irregular packed product, or has a shelf structure.

[0030] In the ethanol distillation apparatus of the present invention, ethanol purified by crude ethanol power is obtained.

[0031] Then, the first column formed with the tower top force also directed downward, the second column formed adjacent to the first column via the partition, and upward from the tower bottom It has at least a distillation column provided with a third column that is formed and communicates with the first and second columns. The invention's effect

[0032] According to the present invention, ethanol can be obtained by a method for distilling ethanol, which is then purified by crude ethanol power.

[0033] In one distillation method, a first column formed with a column top force also directed downward, a second column formed adjacent to the first column via a medium cut, and a column A distillation column having a third column formed from the bottom to the top and communicating with the first and second columns is used.

[0034] In this case, it is preferable that only three distillation columns are provided, and it is only necessary to provide the auxiliary equipment and the instrument for three series. Therefore, the energy consumed can be reduced, the distillation apparatus can be reduced in size, and the cost of the distillation apparatus and the cost for distilling ethanol can be reduced.

Brief Description of Drawings

FIG. 1 is a view showing an example of a conventional distillation apparatus.

FIG. 2 is a diagram showing a distillation apparatus in the first embodiment of the present invention.

FIG. 3 is a conceptual diagram of the first distillation column in the first embodiment of the present invention.

FIG. 4 is a conceptual diagram of a second distillation column in the first embodiment of the present invention.

FIG. 5 is a diagram showing a distillation apparatus in a second embodiment of the present invention. FIG. 6 is a diagram showing a distillation apparatus in a third embodiment of the present invention.

FIG. 7 is a conceptual diagram of a pilot distillation experimental device.

FIG. 8 is a conceptual diagram when performing distillation calculation by simulation of the first distillation column. Explanation of symbols

[0036] 21-23 First to third distillation columns

26, 32 dividers

27, 33 1st column

28, 34 Second column

29, 35 3rd column

36 columns

111 extractive distillation tower

112 rectifying tower

114 purification tower

115 Demethanol tower

M Crude ethanol

M11, M12, M21 Reboiler

S steam

W

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each embodiment, the trace amount means a predetermined amount of preferably 200 [ppm] or less, more preferably 100 [ppm] or less. In each embodiment, examples of the low boiling point component include those having a boiling point of 60 or less, such as methanol, fusel oil, acetoaldehyde, acetone, and the like.

[0039] In the figure, 21 is a first distillation column for purifying ethanol, 22 is a second distillation column for purifying ethanol and separating methanol, and 23 is a third distillation column for concentrating and separating fusel oil components. The first to third distillation columns 21 to 23 are arranged in order and operated. Made.

[0040] The first distillation column 21 includes a partition 26 extending downward from the top of the column to a predetermined position in the column main body 25 as a can body, and is defined by the partition 26. Thus, the first and second columns 27 and 28 are formed in the respective chambers adjacent to each other. Then, a third column 29 is formed below the first and second columns 27 and 28 in communication with the first and second columns 27 and 28 so that the bottom force is also upward. The

Similarly, the second distillation column 22 is provided with a partition 32 in which the bottom force of the column body 31 extends upward to a predetermined location in the column main body 31 as a can body. Thus, the first and second columns 33 and 34 are formed in the respective chambers adjacent to each other by the chambers thus defined. Then, a third column 35 is formed above the first and second columns 33 and 34 so as to communicate with the first and second columns 33 and 34 and downward from the tower top.

[0042] In addition, 37 is a column body as a can of the third distillation column 23, and 36 is a column of the third distillation column 23.

[0043] In the first to third distillation columns 21 to 23, the first to third columns 27 to 29, 33 to 35, and the column 36 are all in a conventional distillation apparatus when packed with a packing. Theoretically calculated by multiplying the number of plates of the extractive distillation column 11 (see FIG. 1), the rectifying column 12, the destilling column 13, the purification column 14, the demethanol column 15 and the vacuum distillation column 16 by the stage efficiency. It shall have a height corresponding to the number of steps.

[0044] Further, in the first distillation column 21, the first column 27 includes three packed beds kl to k3 packed with a packing so that the column top force is also directed downward, and the second column 28 Is provided with three packed beds k4 to k6 filled with packings from the top to the bottom, and the third column 29 has one packed bed k7 packed with packings, In the distillation column 22, the first column 33 is provided with three packed beds kl l to kl3 packed with a packing so that a predetermined positional force in the column main body 31 is also directed toward the column bottom, and the second column 34 includes three packed beds kl4 to kl6 filled with packing from a predetermined position in the column main body 31 toward the bottom of the column, and the third column 35 includes one packed with packing. A packed bed kl7 is provided, and in the third distillation column 23, the column 36 includes three packed beds k21 to k23 packed with packings from the top to the bottom. [0045] In the first distillation column 21, the first concentrating section is packed by the packed bed kl, the first collecting section force is packed by the packed beds k2, k3, and the second concentrating section force is packed by the packed beds k4 to k6. Layer k7 constitutes the second recovery section. Further, in the second distillation column 22, the first concentrated partial force packed bed kl2, kl3 by the packed bed kl l, the first recovery partial force by the packed bed kl7, and the second concentrated partial packed bed kl4-kl6 by the packed bed kl7. Constitutes the second recovery unit. Further, in the third distillation column 23, the packed bed k21 constitutes a concentrating part, and the packed beds k22 and k23 constitute a recovery part.

Then, in the first distillation column 21, the first column 27 is passed through the crude ethanol M force line L 1 as a stock solution containing a trace amount of a low boiling point component, methanol, fusel oil component and the like. Is supplied to the top of the first column 27 via a split hot water W power line L3, which is hot water, between the packed beds kl and k2, which is the middle part of the first column 27. The amount of heat of the first column 27 is a force supplemented by the steam rising from the third column 29. Steam S is blown under the packed bed k3 of the first column 27 as necessary. The vapor VI I discharged from the top of the first column 27 to the line L4 at the top of the tower is condensed by the condensers HI 1 and H21 as the first and second condensing parts, and a very small amount of low A distillate containing a boiling point component and a part of the fusel oil component is supplied to the storage tank R12 via the line L32, and a part of the liquid discharged from the storage tank R12 is supplied to the line L2. Through the top of the first column 27 as reflux, and the remainder is discharged to the line L42 and supplied to the storage tank R14. The condenser HI 1 also serves as a reboiler Mil as a reboiling part connected to the second distillation column 22 in order to effectively use heat.

On the other hand, the liquid that also flows down the lower end force of the first and second columns 27 and 28 is supplied to the upper end of the third column 29. Further, the vapor rising in the third column is distributed and supplied to the first and second columns 27 and 28. The bottoms of the third column 29 having a lower end force discharged to the line L5 is supplied as hot water to the storage tank R11, and the hot water discharged from the storage tank R11 is supplied to the split hot water W via the line L3. As a result, the excess hot water is discharged to the line L6 and discharged outside the system. The third column 29 is heated by blowing steam S into the bottom of the column.

[0048] In addition, the vapor V12 discharged from the second column 28 to the line L7 is condensed by the condensers H12 and H22 as the third and fourth condensing parts, and is a distillate containing methanol. Liquid Thus, a part of the distillate is refluxed as a reflux liquid to the top of the second column 28 via line L8, and the rest is discharged to line L14. The condenser H12 also serves as a reboiler M12 as a reboiling part connected to the third distillation column 23 in order to effectively use heat. The ethanol fraction from which trace amounts of low-boiling components, methanol, fusel oil components, etc. are almost removed is discharged as a side stream from the packed bed k4, k5, which is the middle part of the second column 28, to the line L11. The fusel oil component is concentrated at the lower end of the second column 28, discharged to the lower end force line L12 of the second column 28, and supplied to the storage tank R14.

[0049] The ethanol fraction discharged from between the packed beds k4, k5 of the second column 28 is packed in the intermediate portion of the first column 33 of the second distillation column 22, kl1, kl2. Supplied in between.

[0050] In the second distillation column 22, the vapor rising in the second column 34 contains methanol and is supplied to the third column 35. The bottoms of the first column 33 are also discharged into the line L13, and a part of the bottoms is converted into steam by the reboiler Mil and the reboiler M21 as the reboiler. And recycled to the first column 33. The remainder of the bottoms is supplied as purified ethanol having an ethanol concentration of 95 [vol%] or more and as a product to a predetermined product container. The heating of the first column 33 is performed by exchanging heat with the vapor VI I from which the top power of the first column 27 of the first distillation column 21 is also discharged by the reboiler Mil. The lack of heat is compensated by blowing another steam S with the reboiler M21.

[0051] The distillate from the second column 28 is supplied between packed beds kl4 and kl5, which is an intermediate part of the second column 34, via a line L14, and is distilled from the third distillation column 23. The liquid is supplied between the packed beds kl4 and kl5 of the second column 34 via the line L15, the storage tank R13, and the line L16. Then, in the second distillation column 22, the vapor V13 discharged from the third column 35 to the line L17 is condensed by the condensers H13 and H23 as the fifth and sixth condensing units to form methanol. A part of the distillate is refluxed as a reflux liquid to the top of the third column 35 via the line L18, and the remainder is discharged to the line L19 as methylon.

[0052] In addition, the bottoms of the second column 34 having the bottom force discharged to the line L34 is supplied to the storage tank R12, and the distillate supplied via the line L32 in the storage tank R12. Join The Subsequently, a part of the liquid discharged from the storage tank R12 is supplied as a reflux liquid to the top of the first column 27 of the first distillation column 21 via the line L2, and the rest is stored via the line L42. Supplied to R14. The second column 34 is heated by blowing steam S into the bottom of the column.

[0053] Meanwhile, the liquid in the storage tank R14 is supplied via a line L20 between packed beds k21 and k22 which are intermediate parts of the column 36 of the third distillation column 23 operated under reduced pressure. Then, in the third distillation column 23, the vapor V14 discharged to the line L21 at the top of the column 36 is condensed and condensed by the condensers H14 and H24 as the seventh and eighth condensing parts. A part of the distillate is refluxed as a reflux liquid to the top of the column 36 via the line L22, and the remainder is discharged to the line L15 and supplied to the storage tank R13.

[0054] Then, the fusel oil component is concentrated in the column 36, and discharged to the line L24 as a side stream from between the packed beds k22 and k23, which is an intermediate part of the recovery part. The hot water that is the bottoms of the column 36 that has also been discharged to the line L25 is discharged to the line L26, and a part of the hot water is discharged from the first distillation column 21 in the reboiler M12. The top force of the column 28 of the second column is also heated by exchanging heat with the discharged steam V 12 and is circulated in the column 36 as steam.

[0055] By the way, according to the present embodiment, the ethanol distillation method for producing purified ethanol with crude ethanol strength is carried out by three first to third distillation columns 21-23. In the entire mass balance, crude ethanol M is fed to the first column 27 of the first distillation column 21 and steam S is directly fed to the bottom of the first column 27 and the bottom of the third column 29. To the bottom of the second column 34. Then, the bottom force of the third column 29 and the thermal hydraulic power The bottom force of the first column 33 and the purified ethanol power The methylon force from the top of the third column 35 The column side of the column 36 The fusel oil component force of the column 36 Hot water is also discharged from the bottom of the tower.

[0056] In this way, just by arranging the first to third distillation columns 21 to 23, the squeezing force is also attached to the condensers H11 to H14, H21 to H24, the reboilers Ml 1, M12, M21, etc. Since only three lines of equipment and instrumentation are required, energy consumed can be reduced, and the distillation apparatus can be downsized. Therefore, the area occupied by the distillation apparatus can be reduced. In addition, the cost of the distillation apparatus and the cost for distilling ethanol can be reduced. [0057] Next, the first distillation column 21 will be described in detail.

[0058] FIG. 3 is a conceptual diagram of the first distillation column in the first embodiment of the present invention.

[0059] In the figure, reference numeral 21 denotes a first distillation tower having an upper part having a divided structure and a lower part having an integral structure. The first distillation column 21 includes a column main body 25 having a hemispherical shape at the top and bottom and a cylindrical shape at the body, and the cross section surrounded by the column main body 25 is circular. In this space, a flat plate-like partition 26 is arranged with the tower top force also downward, and the first and second columns 27 and 28 are formed by the partition 26. Each of the first and second columns 27 and 28 has a semicircular cross section, is formed adjacent to each other, and extends downward from the tower top.

[0060] In addition, a third column 29 is formed upward from the tower bottom, and the third column 29 and the first and second columns 27, 28 are communicated with each other.

[0061] In the first column 27, downward from the top, the first section sl, the second section s2, the third section s3, the fourth section s4, the fifth section s5, and the sixth section s6 And 7th section s7 force The 2nd column 28 has the 8th section s8, 9th section s9, 10th section slO, 11th section si 1, 12th section sl2, 13th Section sl3 force In the third column 29, the lower end force of the seventh section s7 and thirteenth section si3 is also directed toward the bottom of the tower, so that each section of the fourteenth section sl4, fifteenth section sl5 and sixteenth section sl6 It is formed.

[0062] Also, the second section s2, the fourth section s4, the sixth section s6, the ninth section s9, the eleventh section si1, the thirteenth section sl3, and the fifteenth section sl5 are not shown. Filling elements consisting of regular fillers, irregular fillers and the like are filled, and the packed layers kl (FIG. 2) to k7 are formed. In the present embodiment, the middle cut 26 is arranged at the center of the tower body 25, but it is not always necessary to arrange it at the center. In addition, the second section s2, the fourth section s4, the sixth section s6, the ninth section s9, the first section 1 si1, the thirteenth section sl3, and the fifteenth section sl5 are formed by a shelf structure. I'll do it.

[0063] At the column side of the first distillation column 21, the feed nozzle 51 force faces the third section s3, and at the top of the first column 27, steams facing the first section si. Air outlet 52, reflux liquid inlet 53 and split hot water inlet 54 force At the tower side of the first column 27, the steam inlet 55 faces the seventh section s7, and the top of the second column 28 The steam outlet 56 and the reflux liquid inlet 57 facing the eighth section s8 are disposed on the column side of the second column 28 so that the liquid outlet 58 force faces the tenth section slO. On the column side of the column 29, the liquid outlet 59 faces the 14th section sl4, and at the bottom of the first distillation tower 21, the bottom outlet 61 and the steam inlet face the 16th section sl6. 62 is formed.

[0064] Furthermore, a perforated plate 63 that distributes the steam rising from the 14th section sl4 to the first column 27 side and the second column 28 side is disposed below the seventh section s7. Is done.

[0065] Then, the first concentrating part force is applied to the second section s2, the first recovery part is provided to the fourth section s4 and the sixth section s6, the ninth section s9, the eleventh section si 1 and the thirteenth section si. A second concentrating part is formed in 3 and a second collecting part is formed in the 15th section s15.

[0066] In the first column 27, when the total number of stages of the fourth section s4 and the sixth section s6 is too large, the fourth section s4 or the sixth section s6 can be removed. Also, in the second column 28, if the total number of the 11th section si 1 and the 13th section sl3 is too large, the 11th section si 1 or the 13th section sl3 can be removed.

[0067] In the first distillation column 21 having the above-described configuration, the crude ethanol M containing a small amount of a low boiling point component, methanol, fusel oil component, and the like passes through the first column via the line L1 and the feed nozzle 51. 27 is supplied to the third section s3 which is the middle part of 27, and the split hot water W is supplied to the first section si via the line L3 and the split hot water inlet 54. The steam containing ethanol and water rising in the second section s2 contains a small amount of low boiling point components and fusel oil components whose volatility increases due to the effect of the split hot water W.

[0068] The steam VI I discharged from the steam outlet 52 to the line L4 is supplied to the condenser HI 1 and is partially condensed, that is, partially condensed. The distillate, which is a liquid formed by partial condensation, is supplied to the storage tank R12 via the lines L31 and L32, and the uncondensed vapor VI I is supplied to the condenser H21 via the line L33. Condensed, that is, fully condensed. The distillate, which is a liquid formed by total condensation, enters storage tank R12 via line L32. Supplied. The bottoms discharged from the second column 34 to the line L34 are also supplied to the storage tank R12 and joined together. A part of the liquid discharged from the storage tank R12 is refluxed as a reflux liquid to the first section si via the line L2 and the reflux liquid inlet 53, and the rest is supplied to the storage tank R14 via the line L42.

[0069] The crude ethanol M supplied to the third section s3 descends the fourth section s4 to the sixth section s6 and exchanges heat with the rising steam to remove a small amount of low-boiling components. Supplied to 14 section sl4. Steam S is blown into the seventh section s7 at the bottom of the first column 27 via the line L40 and the steam inlet 55. Depending on the distillation conditions, the steam S need not be blown. The perforated plate 63 limits the flow rate of the steam flowing from the 14th section s14 to the 7th section s7.

[0070] In this case, the steam S blown into the seventh section s7 is partly supplied through the perforated plate 63 to the fourteenth section sl4, and the steam S is blown into the first column 27. Then, it enters the second column 28 with the methanol and fusel oil components in a vapor state, and is raised in the second column 28. Therefore, since the amount of heat in the first distillation column 21 can be reduced, the amount of energy consumed in the distillation apparatus can be reduced.

[0071] In the fifteenth section sl5, the liquid containing methanol and fusel oil components is blown down from the fourteenth section sl4 and into the sixteenth section sl6 through the line L3 5 and the steam inlet 62. It exchanges heat with steam S to become steam, and rises through the first 4th section s14. Then, the liquid from which ethanol has been removed in the 16th section sl6 is discharged from the bottom discharge outlet 61 to the line L5 as bottom discharge and supplied as hot water to the storage tank R11. Part of the hot water is circulated as split water W in the first section si via line L3, and excess hot water is discharged to line L6 and discharged outside the system.

[0072] The steam containing methanol and fusel oil components rising in the fifteenth section sl5 rises in order from the thirteenth section sl3 to the ninth section s9 and exchanges heat with the reflux liquid descending from the eighth section s8. In this case, methanol is contained in the ethanol fraction rising up the 8th section s8, and the vapor V12 discharged from the vapor outlet 56 to the line L7 at the top of the tower is supplied to the condenser H12 to be partially condensed. It is done. Formed by partial condensation A portion of the distillate, which is a fresh liquid, is returned to the eighth section s8 as a reflux liquid via lines L36 and L37 and a reflux liquid inlet 57. The uncondensed vapor is supplied to the condenser H22 via the line L38 and is fully condensed. A part of the distillate, which is a liquid formed by total condensation, is refluxed as reflux to the eighth section s8 via lines L39 and L37 and the reflux inlet 57, and the rest is discharged as lines L39 and L14. The

[0073] The reflux liquid refluxed to the eighth section s8 exchanges heat with the rising steam while descending in the second column 28, and methanol is removed in the ninth section s9, so that the tenth section. The ethanol fraction is discharged from slO through the liquid outlet 58 to the line LI 1 as a side stream. The remaining liquid in the 10th section slO descends by exchanging heat with the rising steam in the 11th section si1 to the 13th section sl3. The liquid reaching the lower part of the 13th section sl3 has a high fusel oil component concentration, and the concentrated fusel oil component is discharged from the 14th section sl4 as a side flow into the line L12 via the liquid outlet 59. After that, it is supplied to storage tank R14. In the storage tank R14, the liquid in the storage tank R12 also passes through the line L42.

The liquid in the storage tank R14 is supplied to the third distillation column 23 via the line L20.

[0074] Next, the second distillation column 22 will be described in detail.

FIG. 4 is a conceptual diagram of the second distillation column in the first embodiment of the present invention.

[0076] In the figure, reference numeral 22 denotes a second distillation column having an integral structure in the upper part and a divided structure in the lower part. The second distillation column 22 has a hemispherical shape at the top and bottom. The tower body 31 has a cylindrical shape with a cylindrical portion, and is a flat partition having a circular cross-section surrounded by the tower body 31 and a tower bottom force upward. The first and second columns 33 and 34 are formed by the partition 32. The first and second columns 33 and 34 both have a semicircular shape in cross section, are formed adjacent to each other, and extend upward toward the bottom force.

[0077] In addition, a third column 35 is formed downward from the top of the column, and the third column 35 and the first and second columns 33 and 34 are communicated with each other.

[0078] The third column 35 has a first section s21, a second section s22, and a third section s23 downward from the top of the tower, and the first column 33 has a third section s23. Under Towards the bottom of the tower, the 4th section s24, 5th section s25, 6th section s26, 7th section s27, 8th section s28, and 9th section s29 force From the lower end of the section s23 to the tower bottom, the sections of the 10th section s30, 11th section s31, 12th section s32, 13th section s33, 14th section s34 and 15th section s35 are formed in order.

[0079] Further, the second section s22, the fourth section s24, the sixth section s26, the eighth section s28, the tenth section s30, the twelfth section s32 and the fourteenth section s34 are not shown in the figure. Filler elements consisting of materials, irregular fillers, etc. are filled to form the packed layers kl7 (FIG. 2) and kl1 to kl6. In the present embodiment, the partition 32 is arranged at the center of the tower body 31, but it is not always necessary to arrange it at the center. Further, the second section s22, the fourth section s24, the sixth section s26, the eighth section s28, the tenth section s30, the twelfth section s32, and the fourteenth section s34 may be formed by a shelf structure.

[0080] At the tower side of the first column 33, the feed nozzle 71 faces the fifth section s25, and at the bottom of the first column 33, the feed nozzle 71 faces the ninth section s29. An outlet 72 and a steam inlet 73 are formed. Also, on the tower side of the second column 34, it faces the 11th section s31, feed nozzle 74, 75 force At the bottom of the second column 34, it faces the 15th section s35, and the can is taken out. A liquid outlet 76 and a steam inlet 77 are formed. A vapor outlet 78 and a reflux liquid inlet 79 are formed at the top of the third column 35 so as to face the first section s21.

[0081] The first concentrating force in the fourth section s24 is the first collecting portion in the sixth section s26 and the eighth section s28, and the second concentrating force is in the second section s22. Second recovery sections are formed in the sections s32 and 14th section s34, respectively.

[0082] In the first column 33, the sixth section s26 and the eighth section s28

If there are too many total stages, the sixth section s26 or the eighth section s28 can be removed. Also, in the second column 34, if the total number of stages of the twelfth section s32 and the fourteenth section s34 is too large, the twelfth section s32 or the fourteenth section s34 can be removed. [0083] In the second distillation column 22 having the above-described configuration, an intermediate partial force of the second column 28 of the first distillation column 21 is also obtained as a side stream through the ethanol fractional force line LI 1 and the feed nozzle 71. Supplied to the fifth section s25. Also, in place of the ethanol fraction, a general ethanol distillation may remove a small amount of low boiling point components and fusel oil components and supply the ethanol fraction in which methanol remains to the fifth section s25. it can. The liquid in the fifth section s25 is subjected to heat exchange with the steam rising from the bottom in the sixth section s26 to the eighth section s28, and methanol is removed.

[0084] A part of the bottoms discharged to the line L13 via the bottom outlet 72 of the ninth section s29 is supplied to the reboiler Mil, and is converted into steam by the reboiler Mil. And is circulated to the ninth section s29 via the line L51 and the steam inlet 73. In order to compensate for the amount of vapor rising up the first column 33, i.e., the shortage of vapor, a portion of the liquid in line L13 is fed to reboiler M21, where steam S Is heated to become steam and is circulated to the ninth section s29 via the line L51 and the steam inlet 73. The remainder of the bottoms is discharged to the line L52 as purified ethanol and as a product.

[0085] The steam rising from the fifth section s25 of the first column 33 toward the top of the column is the steam of an ethanol fraction containing methanol, and passes through the fourth section s24, the third section s23, and the second section s22. to go into. In the second section s22, the steam exchanges heat with the reflux liquid descending from the top of the column, and the concentration of methanol increases, and the steam is discharged from the first section s21 through the steam outlet 78 to the line L17, where the condenser is It is supplied to H13 and partially condensed by the condenser H13.

[0086] A part of the distillate, which is a liquid formed by partial condensation, is refluxed to the first section s21 via the lines L53, L18 and the return liquid inlet 79 as a reflux liquid. The uncondensed vapor is supplied to the condenser H23 via the line L54, and is totally condensed in the condenser H23. A part of the distillate, which is a liquid formed by total condensation, is returned to the first section s21 as the reflux liquid via lines L55, L56, L18 and the reflux liquid inlet 79, and the remainder is returned to line L19 as methylon. To be discharged.

[0087] The reflux liquid refluxed to the first section s21 is supplied to the second section s22 and the third section s23. After that, it flows into the 10th section s30. The eleventh section s31 is supplied through the distillate liquid power line L15, the storage tank R13, the line L16, and the feed nozzle 75 containing a small amount of low-boiling components in the third distillation column 23. The distillate containing methanol from the column 28 is also supplied via the line L 14 and the feed nozzle 74. These ethanol fractions containing a small amount of low-boiling components and methanol are heat-exchanged with the vapor rising in the second column 34 and discharged from the third column 35 to form a distillate. ) Is discharged out of the system.

[0088] The liquid descending from the 11th section s31 is supplied via the line L58 and the steam inlet 77 in the 15th section s35 at the bottom of the tower, and exchanges heat with steam rising from the 14th section s34 to the 12th section s32. As the trace amount of low-boiling-point components and methanol become vapor, it descends as an ethanol liquid richer in water, then from the 15th section s 35 at the bottom of the tower through the bottom outlet 76. Drained into line L34 as effluent, storage tank

Supplied to R12. The distillate supplied from the condenser H21 via the line L32 is also supplied to the storage tank R12.

[0089] The liquid discharged from the storage tank R12 is supplied to the storage tank R14 via the line L42, and is also refluxed as a reflux liquid to the top of the first column 27 via the line L2. The concentrated fusel oil component discharged from the 14th section sl4 of the third column 29 is also supplied to the storage tank R14 via the line L12. Then, the liquid discharged from the storage tank R14 is supplied via the line L20 to the third distillation column 23 operated under reduced pressure.

[0090] Next, a second embodiment of the present invention will be described. Note that those having the same structure as the first embodiment are given the same reference numerals, and the description thereof is omitted, and the effects of the same embodiment are used for the effects of the invention by having the same structure. The

FIG. 5 is a diagram showing a distillation apparatus in the second embodiment of the present invention.

[0092] In this case, the ethanol fraction discharged as a side stream from between the packed beds k4 and k5, which is the middle part of the second column 28 of the first distillation column 21, has an ethanol concentration of 95 vol% or more. In this state, it is supplied to the 33rd stage of the purification tower 114 via the line L11. The steam rising up the purification tower 114 contains methanol, and the steam discharged from the top of the purification tower 114 is condensed by the ninth and tenth condensations. Condensers H15 and H25 as a part are condensed into a distillate, and a part of the distillate is refluxed as a reflux liquid at the top of the purification tower 114, and the rest is supplied to the demethanol tower 115. . In addition, the bottoms from the bottom of the purification tower 114 are discharged as purified ethanol having an ethanol concentration of 95 [vol%] or more to the line L101 as a product. Then, the liquid at the bottom of the purification tower 114 is made a vapor by the reboiler M11 as a reboiling part and circulated to the purification tower 114. In the reboiler Ml 11, the amount of heat of the steam VI I discharged from the top of the first column 27 of the first distillation column 21 is used, and the insufficient amount of heat is used as another reboiling part. In reboiler Ml 12, it is supplemented by heating by blowing in steam S.

[0093] The distillate from the second column 28 passes through the line L14 to the 25th stage of the demethanol tower 115, and the distillate from the third distillation tower 23 passes through the line L15, the storage tank R13, and the line L16. Are supplied to 25 stages of the demethanol tower 115 respectively. The vapor discharged from the top of the demethanol tower 115 is condensed by the condensers H16 and H26 as the eleventh and twelfth condensing sections to form a distillate containing methanol. A part of the water is refluxed as a reflux liquid to the top of the demethanol tower 115 and the rest is discharged as methylon. The bottoms from the demethanol tower 115 are supplied to the storage tank R12, merged with the distillate from the first column 27, and a part of the liquid discharged from the storage tank R12 passes through the first line L2. Is supplied to the top of column 27, and the remainder is supplied to storage tank R14 via line L42. The demethanol tower 115 is heated by blowing steam S into the bottom of the tower.

[0094] In the present embodiment, the process of the ethanol distillation method for producing the crude ethanol M-purified ethanol is constituted by four distillation columns, and the mass balance of the entire process is that the crude ethanol M is the first column. The steam S is supplied directly to the bottom of the first column 27, the bottom of the third column 29, and the bottom of the demethanol tower 115. Then, the bottom force of the third column 29 and the hydrothermal power The bottom force of the purification tower 114 and the purified ethanol force The demethanol tower 115 the top force and the methylon force Column 36 The column side force and the fusel oil component force Column 3 6 tower Bottom power Hot water is discharged.

[0095] Next, a third embodiment of the present invention will be described. Note that those having the same structure as the first embodiment are given the same reference numerals, and the description thereof is omitted. The same structure

As for the effect of the invention by having the structure, the effect of the embodiment is cited.

FIG. 6 is a diagram showing a distillation apparatus according to the third embodiment of the present invention.

In the figure, 111 is an extractive distillation column, 112 is a rectifying column, and the rectifying column 112 is a plate column and has 65 plates.

[0098] Crude ethanol M containing a small amount of low-boiling components, methanol, fusel oil components and the like is supplied to the upper 35 stages of extractive distillation column 111 via line L1. Also, split water W, which is hot water, is supplied to the top of the extractive distillation column 111 via line L3. The extractive distillation column 111 is heated by blowing steam S into the bottom of the column. The vapor VI I discharged from the top of the extractive distillation column 111 is condensed by the condensers H31 and H35 as the 13th and 14th condensing parts, and contains a small amount of low boiling point components and fusel oil components. It becomes a distillate, and a part of the distillate is refluxed as a reflux liquid at the top of the extractive distillation column 111, and the rest is supplied to the storage tank R14. The condenser H31 also serves as the reboiler Mil of the second distillation column 22 in order to effectively use heat.

[0099] The bottoms of the extractive distillation column 111 is supplied to the lower 15 stages of the rectifying column 112. The effluent from the rectification column 112 is circulated to the top of the extractive distillation column 111 as split hot water W via the storage tank Rl 1 and the line L3, and surplus hot water is discharged to the line L6. Vapor V12 discharged from the top of the rectifying column 112 is condensed by condensers H32 and H36 as the 15th and 16th condensing parts into a distillate containing methanol, and a part of the distillate Is refluxed as a reflux liquid at the top of the rectifying column 112, and the rest is discharged to the line L14. The condenser H32 also serves as the reboiler M12 of the third distillation column 23 in order to effectively use heat.

[0100] The ethanol fraction from which a small amount of low-boiling components and fusel oil components have been substantially removed is also discharged to the line LI 1 as a side stream by the 63-stage force at the bottom of the upper filling section of the rectifying column 112. In addition, the fusel oil component is concentrated in the middle part of the rectifying column 112 and supplied from the 19th stage to the storage tank R14 via the line L12. The rectifying column 112 is heated by blowing steam S into the bottom of the column.

[0101] The ethanol fraction discharged from the rectification column 112 as a side stream of 63-stage force has an ethanol concentration of 95 vol% or more, and the packed bed kl l, kl2 of the first column 33 via line L11 Supply in between Is done. The vapor rising in the first column 33 contains methanol and is supplied to the third column 35. A part of the bottoms of the first column 33 is heated by the reboiler Mil, becomes steam, and is circulated to the first column 33. The remainder of the bottom is discharged as purified ethanol having an ethanol concentration of 95 vol% or more. In the reboiler Mil, the amount of heat of the steam VI I discharged from the top of the extractive distillation column 111 is used, and the insufficient amount of heat is saved by another reboiler M21.

[0102] The distillate from the rectification column 112 is supplied between the packed beds kl4 and kl5 in the upper part of the second column 34.

[0103] In the present embodiment, the process of the ethanol distillation method for producing crude ethanol M-purified ethanol is composed of four distillation columns, and the mass balance of the entire process is that the crude ethanol M is an extractive distillation column 111. Steam S is supplied to the bottom of each of the extractive distillation column 111, the rectifying column 112, and the second column 34. The hot water is supplied from the bottom of the rectifying column 112, the bottom force of the first column 33 and the purified ethanol power. The top force of the third column 35 is methylone, and the fusel oil component power is supplied from the column side of the column 36 to the column 36. Hot water is discharged even at the bottom of the tower

Next, an example using the first distillation column 21 of the present invention will be described. In this case, the experiment was conducted using a pilot distillation experimental device. In the pilot distillation experimental apparatus, the same parts as those of the first distillation column 21 will be described using the same reference numerals.

FIG. 7 is a conceptual diagram of a pilot distillation experimental apparatus.

[0106] 31; 3304 (thickness 8, schlOS) having an inner diameter of 158.4 [111111] is used as the tower body 25, and Sulzer metal gauze packing, Type is used as the packing element of each packed bed kl to k7. CY (Sumitomo Heavy Industries, Ltd.) was used. The height of one layer of each packing element is 950 [mm], which corresponds to about 9 theoretical plates. The partition 26 of the first and second columns 27 and 28 is arranged in the center. The abbreviations of chemical components used here are as follows.

[0107] EtOH: Ethanol

MeOH: Methanol i-PrOH: Isopropyl alcohol

n PrOH: n-propanol

i BuOH: Isobutyl alcohol

H O: Water

2

(Example 1)

The distillation was carried out in a stable continuous operation under normal pressure. The set flow rate at each location is as follows when expressed in [kgZ time].

Crude ethanol M 4. 35

Wariyu W 40. 0

Hot water supplied to the bottom of tower 0. 111

First column 27 distillate E1 0. 473

First column 27 reflux F1 17. 0

Second column 28 distillate E2 3.718

Second column 28 reflux solution F2 44.0

Second column 28 sidestream G2 0.270

The temperature at each point pl to pl2 in FIG.

Pi 89. 2

P2 87.7

P3 65.9

P4 86.9

P5 78. 5

p6 78. 2

P7 80. 1

P8 96.7

P9 102.0

plO 25. 5

pl l 21.2

pl2 84. 5 The composition of crude ethanol M, distillate El, E2, and sidestream G2 is expressed as follows in terms of weight [%].

[0110] [Table 1]

(Example 2)

[0111] Crude ethanol M 4. 40

Wariyu W 30. 0

Hot water supplied to the bottom of the tower 0. 198

First column 27 distillate E1 0. 471

First column 27 reflux solution F1 20. 0

Distillate from second column 28 E2 3. 829

Second column 28 reflux F2 49. 8

Second column 28 sidestream G2 0. 301

The temperature at each point pl to pl2 in FIG.

[0112] pi 87. 1

p2 86.5

p3 67. 0

p4 85. 8 p5 78. 6

p6 78. 3

p7 80. 1

p8 97.9

p9 102.0

plO 25. 3

pl l 18. 4

pl2 81.4

The composition of crude ethanol M, distillate El, E2, and sidestream G2 is expressed as follows in terms of weight [%].

[Table 2]

In Examples 1 and 2, the side stream G2 is discharged only at one location due to the structure of the pilot distillation experimental apparatus. However, in Examples 1 and 2, i PrOH and i-BuOH are almost removed from the side stream G2 from the power distillate El in which the amount of the split hot water W and the amounts of the reflux liquids Fl and F2 are changed. The n-PrOH is almost removed, and the distillate E2 of the second column 28 contains only trace amounts of components other than MeO H, and the purpose of distillation is achieved.

Next, the results of distillation calculation by simulation of the first distillation column 21 of the present invention will be shown. Actual results of plant operation and simulation-based distillation calculations have a large track record, such as “ASPENPLUS” (manufactured by “ASPENTEC”). A commercially available process simulator can be used.

FIG. 8 is a conceptual diagram in the case of performing distillation calculation by simulation of the first distillation column.

[0116] In this case, Sulzer metal gauze packing, Type BX (manufactured by Sumitomo Heavy Industries, Ltd.) was used as the packing element, and 96 [%] purified ethanol was produced by continuous distillation 60 [KLZ days]. did. The number of theoretical plates of the first column 27 is 40, and the crude ethanol M was supplied to the feed nozzle 51 12 steps below the top of the first column 27. The number of theoretical plates in the second column 28 is 40, and the ethanol fraction was discharged as a side stream G2 from the tower body 25 one stage below the top of the tower. In addition, the liquid containing the fusel oil component was discharged from the four-stage nozzle 92 and the second-stage nozzle 93 at the bottom of the second column 28 to the storage tank R14 (FIG. 6) as the side stream G12, G13. The number of theoretical plates in the third column 29 is 12. The tower diameter is 1.8m.

[0117] When the continuous distillation is performed under normal pressure, the set flow rate at each location in FIG. 8 is as follows when expressed in [kg Z time]. This flow rate is the same as that in the extractive distillation column 11, the rectifying column 12, and the dehydrating column 13 in FIG. 1 when 96% of purified ethanol in a conventional distillation apparatus is produced by continuous distillation 60 [KL / day]. Corresponds to the operation results.

[0118] Crude ethanol M 2, 192

Wariyu W 14, 930

First column 27 distillate E1 231

First column 27 reflux F1 3, 109

Second column 28 distillate E2 162

Second column 28 reflux F2 8, 798

Liquid flowing into storage tank R12 H 1, 343

Descent in tower ¾J 20, 234

Steam S 0 blown into the bottom of the first column 27 (conventional distillation apparatus 1, 400 in Fig. 1)

Steam S 5,400 blown into the bottom of the third column 29 (conventional distillation unit 4,000 in Fig. 1)

Sidestream of second column 28 G2 2, 412

Second column 28 佃 j-flow G12 183 Second column 28 佃 j-flow G 13 184

Bottomed liquid K 20, 693

Eliminating the supply of steam S at the bottom of the first column 27 and increasing the supply of steam S at the bottom of the third column 29 will have little effect on the distillation separation.

Yes

Yes.

The temperature of each part p21 to p34 is as follows when expressed in [denoted].

p27 64. 4

p33

p34 100. 5

For crude ethanol M, distillate El, E2, influent H, descending in the tower ¾ !, split hot water W, bottoms K, and side streams G2, G12, G13, each composition is expressed in weight [%]. It is as follows. The values in parentheses represent values in the conventional distillation apparatus in FIG.

[Table 3] Crude ethanol M Distillate E 1 Distillate E 2

EtOH 93. 8872

MeOH 0. 0036 0, 0000 (0. 0005) 0. 0090 (0. 0148) i-PrOH 0. 0005 0. 0039 (0. 0029) 0. 0003 (0. 0000) n-PrOH 0. 0187 0. 0022 (0. 0077) 0. 0000 (0. 0000)

H ₂ 0 6. 09

[0122] [Table 4]

o

[0123] [Table 5]

From the results of the distillation calculation by simulation, the impurity composition at each location is a value that approximates the performance of the conventional distillation equipment, and the side stream G2 of the second column 28, which is the purpose of distillation Makes a good yarn.

[0124] Next, the results of distillation calculation by simulation of the second distillation column 22 in the present invention will be shown. In the second distillation column 22 shown in FIG. 2, MELLAPAK 250Y (manufactured by Sumitomo Heavy Industries, Ltd.) is used as the packing element, and 96% of the purified ethanol is continuously distilled by 60 [KL / day. It was manufactured. The number of theoretical plates of the first column 33 was 40, and the side stream G2 of the second column 28 of FIG. The number of theoretical plates of the second column 34 is 40, and the upper force is also 15 lower, and the distillate E2 of the second column 28 in FIG. 8 of the first distillation column 21 and the third distillation column 23 of FIG. Distillate was supplied via storage tank R13. The column bottom force of the first column 33 also discharged purified ethanol, and the steam was returned to the column bottom by a reboiler Mil. The bottoms of the second column 34 was discharged into the storage tank R12 and steam S was blown into the bottom. The third column 35 has 10 theoretical plates. The tower diameter is 1.25m.

[0125] The flow rate set in each part of the second distillation column 22 shown in Fig. 2 when performing continuous distillation under normal pressure is expressed as [kgZ time] as follows. The flow rate corresponds to the operation results in the purification tower 14 and the demethanol tower 15 in Fig. 1 when 96 [%] purified ethanol in a conventional distillation apparatus is produced by continuous distillation 60 [KL / day]. is doing.

[0126] Sidestream of second column 28 G2 2, 412

Second column 28 distillate E2 162

Distillate from third distillation column 23 365

Equivalent calorific value of steam S supplied to reboiler M21 700

(1,000 in the purification tower 14 of the conventional distillation apparatus in Fig. 1)

Steam S 592 blown into the bottom of the second column 34

Methylon 16

Reflux to the top of the third column 35 5, 412

Liquid distribution to the top of the first column 33 4, 046

Purified ethanol 2, 250

Second column 34 bottoms 1, 265 The concentration of MeOH at each location is as follows when expressed in [ppm]. In addition, the value in a parenthesis represents the value in the conventional distillation apparatus.

[0127] Second column 28 sidestream G2 26 (32)

Distillate from second column 28 E2 91 (181)

Purified ethanol 1.4 (1. 1)

Methylon 4, 900 (5, 980)

Second column 34 bottoms 0.4 (1. 0)

From the results of the distillation calculation by simulation, the impurity composition at each location is a value that approximates the performance of the conventional distillation equipment, and the bottom power of the first column 33, which is the purpose of distillation, is the purified ethanol that is discharged. The methanol contained is sufficiently low.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified based on the gist of the present invention, and does not exclude the scope of the present invention.

Industrial applicability

The present invention can be applied to a distillation apparatus for obtaining purified ethanol for beverages or industrial use from crude ethanol.

Claims

The scope of the claims

[1] Crude ethanol power In the ethanol distillation method for obtaining purified ethanol, at least a first column formed downward from the top of the column, and the first column via a partition. A second column formed adjacent to the column and a distillation column including a third column formed upward from the column bottom and communicating with the first and second columns are used. How to distill ethanol.

[2] The distillation column is a first distillation column. In the first distillation column, crude ethanol is supplied to an intermediate portion of the first column, and hot water discharged from the bottom of the third column is discharged. While refluxing to the top of the first column, excess hot water is discharged, and each top power of the first and second columns is condensed to form a distillate. A part of the liquid is circulated through the first and second columns, respectively, the remainder of the distillate is discharged, and the ethanol fraction is discharged as a side stream from the middle part of the second column. The concentrated diesel oil component is discharged as a side flow of the lower part of the gas, and the third column is heated by blowing steam into the bottom of the column, and if necessary, the first column is heated. The method for distilling ethanol according to claim 1, which is carried out by blowing steam into the lowermost part.

[3] The ethanol fraction obtained by removing a small amount of low-boiling-point components and fusel oil components from ethanol fraction obtained as an intermediate force side stream of the second column of the first column of the first distillation column or in ethanol distillation, leaving methanol remaining. In the ethanol distillation method to obtain purified ethanol from the first column, the first column formed with the tower bottom force upward also, the second column formed adjacent to the first column through the partition. A method for distilling ethanol, comprising using a column and a second distillation column formed downward from the top of the column and provided with a third column communicating with the first and second columns.

[4] In the second distillation column, the ethanol fraction is supplied to an intermediate portion of the first column, and a distillate of the second column of the first distillation column and a fraction of the third distillation column are supplied. The effluent is supplied to the middle part of the second column, the vapor discharged from the top of the column is condensed into a distillate, and a part of the distillate is refluxed to the third column as a reflux liquid. The remainder of the distillate is discharged, the reflux liquid is distributed to the first and second columns, and the bottom of the first column is partly discharged into the first column. Circulate through the column, and the remainder of the bottoms is purified. A portion of the bottoms discharged from the bottom of the second column is circulated to the top of the first column of the first distillation column, and the remainder of the bottoms is recycled to the second column. 3 is fed to the middle part of the distillation column 3, and the heating of the first column is exchanged by the reboiler with the steam discharged from the top of the first column of the first distillation column. 4. The method for distilling ethanol according to claim 3, wherein the second column is heated by blowing steam into the column bottom, and the second column is heated by blowing steam with another reboiler.

[5] In a third distillation column having a concentrating unit and a recovery unit without partitioning, a part of the distillate from the first column of the first distillation column, the first distillation column of the first distillation column, The concentrated fusel oil component discharged from the lower part of the column 2 and the second column bottom of the second distillation column are operated under reduced pressure and discharged from the top of the column. The condensed vapor is condensed into a distillate, a part of the distillate is refluxed as a reflux liquid to the concentrating section, and the remainder of the distillate is passed through an intermediate part of the second column of the second distillation column. The concentrated fusel oil component is discharged as a side stream from the intermediate part of the recovery unit, and a part of the hot water from which the bottom force of the column is also discharged is recirculated by the reboiler. The tower top force of the second column is heated by exchanging heat with the discharged steam, is converted into steam, is circulated to the recovery section, and the remaining hot water is discharged. The method for distilling ethanol according to 1.

[6] The method for distilling ethanol according to claim 4, wherein the first to third distillation columns are sequentially arranged and operated.

[7] The ethanol distillation method according to [5], wherein the first to third distillation columns are sequentially arranged and operated.

[8] In the ethanol distillation method for obtaining ethanol with a crude ethanol power, the first distillation column, purification column and demethanol column were used for ethanol purification and methanol separation. A method for distilling ethanol, wherein the fusel oil component is concentrated and separated.

[9] Ethanol distillation removes traces of low-boiling components and fusel oil components, and purifies ethanol from the ethanol fraction in which methanol remains, using the second and third distillation columns. The method for distilling ethanol according to claim 3, wherein methanol is separated and fusel oil components are concentrated and separated.

[10] The method for distilling ethanol according to any one of [1] to [9], wherein each column is filled with a regular packing or an irregular packing, or has a shelf structure.

[11] In the ethanol distillation apparatus for obtaining purified ethanol, the crude ethanol power is formed by adjoining the first column through the partition, the first column formed downward from the top of the column. An ethanol distillation apparatus comprising at least a second column and a distillation column having a third column formed upward from the bottom of the column and communicating with the first and second columns.