U.S. patent application number 10/428142 was filed with the patent office on 2003-10-02 for distillation apparatus and distillation method.
This patent application is currently assigned to SUMITOMO HEAVY INDUSTRIES, LTD.. Invention is credited to Harada, Yoichi, Tamura, Katsunori.
Application Number | 20030183501 10/428142 |
Document ID | / |
Family ID | 27481550 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030183501 |
Kind Code |
A1 |
Tamura, Katsunori ; et
al. |
October 2, 2003 |
Distillation apparatus and distillation method
Abstract
A distillation apparatus includes a column body; a partition for
dividing the interior of the column body; a first distillation
section composed of an enriching section and an exhaust section; a
second distillation section composed of an enriching section formed
above an upper end of the first distillation section, and an
exhaust section located adjacent to the enriching section of the
first distillation section; a third distillation section composed
of an enriching section located adjacent to the exhaust section of
the first distillation section, and an exhaust section formed below
a lower end of the first distillation section; a condenser; a
negative pressure generation system for generating a negative
pressure to thereby withdraw vent gas; a gas cooler for cooling the
vent gas; a first discharge system disposed at the side of the
column body and adapted to discharge liquid rich in a
medium-boiling-point component formed from a high-melting-point
material; and a second discharge system disposed at the bottom of
the column body and adapted to discharge liquid rich in a
high-boiling-point component formed from a high-melting-point
material. The first discharge system includes a first
solidification prevention system for preventing solidification of
the liquid rich in the medium-boiling-point component. The second
discharge system includes a second solidification prevention system
for preventing solidification of the liquid rich in the
high-boiling-point component.
Inventors: |
Tamura, Katsunori; (Saitama,
JP) ; Harada, Yoichi; (Tokyo, JP) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN, PLLC
SUITE 400
1050 CONNECTICUT AVENUE, N.W.
WASHINGTON
DC
20036-5339
US
|
Assignee: |
SUMITOMO HEAVY INDUSTRIES,
LTD.
|
Family ID: |
27481550 |
Appl. No.: |
10/428142 |
Filed: |
May 2, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10428142 |
May 2, 2003 |
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09813022 |
Mar 21, 2001 |
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6582564 |
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Current U.S.
Class: |
203/1 ; 159/47.1;
159/DIG.20; 196/111; 203/100; 203/48; 203/73; 203/74; 203/77;
203/78; 203/80; 203/99; 203/DIG.17 |
Current CPC
Class: |
B01D 3/14 20130101; B01D
3/141 20130101 |
Class at
Publication: |
203/1 ; 203/48;
203/73; 203/78; 203/80; 203/99; 203/DIG.017; 203/74; 203/77;
196/111; 159/47.1; 159/DIG.020; 203/100 |
International
Class: |
B01D 003/14 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 22, 2000 |
JP |
2000-250777 |
Aug 30, 2000 |
JP |
2000-260130 |
Aug 31, 2000 |
JP |
2000-262185 |
Sep 12, 2000 |
JP |
2000-275909 |
Claims
What is claimed is:
1. A distillation method employing a distillation apparatus
comprising a column body; a partition for dividing the interior of
the column body into a first chamber and a second chamber, which
are adjacent to each other; a first distillation section having a
first enriching section, to which a material liquid is fed through
a feed nozzle and which is formed above the feed nozzle, and a
first exhaust section formed under the feed nozzle; a second
distillation section having a second enriching section connected to
and formed above an upper end of the first distillation section,
and a second exhaust section formed below the upper end and located
adjacent to the first enriching section of the first distillation
section while being separated from the same by the partition; and a
third distillation section having a third enriching section
connected to and formed above a lower end of the first distillation
section, and located adjacent to the first exhaust section of the
first distillation section while being separated from the same by
the partition, and a third exhaust section formed below the lower
end; said distillation method comprising the steps of: (a) feeding
an adjusted material liquid comprising a material liquid and an
additive component to the first distillation section through the
feed nozzle; (b) condensing vapor rich in the additive component
into liquid rich in the additive component at the top of the column
body; (c) discharging the liquid rich in the additive component as
distillate; (d) discharging liquid rich in a low-boiling-point
component formed from a high-melting-point material at the side of
the column body; and (e) discharging liquid rich in a
high-boiling-point component at the bottom of the column body,
wherein (f) the boiling point of the additive component is lower
than that of the low-boiling-point component.
2. A distillation method employing a distillation apparatus
according to claim 1, wherein (a) a portion of the distillate is
refluxed into said column body; and (b) the remaining distillate is
added as an additive component to the material liquid.
3. A distillation method employing a distillation apparatus
according to claim 1, wherein (a) a portion of the distillate is
refluxed into said column body; (b) the remaining distillate is
discharged; and (c) an additive component is added for
replenishment in an amount corresponding to the amount of the
distillate to be discharged.
4. A distillation method employing a distillation apparatus
according to claim 1, wherein (a) all of the distillate is refluxed
into said column body; and (b) in order to start operation of said
distillation apparatus, an additive component is added in a
predetermined amount to the material liquid.
5. A distillation method employing a distillation apparatus
according to claim 1, wherein: (a) a negative pressure is generated
to thereby withdraw vent gas from said column body; and (b) the
vent gas is cooled.
6. A distillation method employing a distillation apparatus
according to claim 1, wherein solidification of the liquid rich in
the low-boiling-point component is prevented.
7. A distillation method employing a distillation apparatus
comprising a column body; a partition for dividing the interior of
the column body into a first chamber and a second chamber, which
are adjacent to each other; a first distillation section having a
first enriching section, to which a material liquid is fed through
a feed nozzle and which is formed above the feed nozzle, and a
first exhaust section formed under the feed nozzle; a second
distillation section having a second enriching section connected to
and formed above an upper end of the first distillation section,
and a second exhaust section formed below the upper end and located
adjacent to the first enriching section of the first distillation
section while being separated from the same by the partition; and a
third distillation section having a third enriching section
connected to and formed above a lower end of the first distillation
section, and located adjacent to the first exhaust section of the
first distillation section while being separated from the same by
the partition, and a third exhaust section formed below the lower
end; said distillation method comprising the steps of: (a) feeding
an adjusted material liquid comprising a material liquid and an
additive component to the first distillation section through the
feed nozzle; (b) condensing vapor rich in a low-boiling-point
component into liquid rich in the low-boiling-point component at
the top of the column body; (c) discharging the liquid rich in the
low-boiling-point component at the top of the column body; (d)
discharging liquid rich in a high-boiling-point component at the
side of the column body; (e) discharging liquid rich in the
additive component as a column-bottom liquid at the bottom of the
column body; and (f) evaporating the column-bottom liquid to
thereby obtain vapor rich in the additive component, wherein (g)
the boiling point of the additive component is higher than that of
the high-boiling-point component.
8. A distillation method employing a distillation apparatus
according to claim 7, wherein (a) a portion of the column-bottom
liquid is fed to said evaporator; and (b) the remaining
column-bottom liquid is added as an additive component to the
material liquid.
9. A distillation method employing a distillation apparatus
according to claim 7, wherein (a) most of the column-bottom liquid
is fed to said evaporator; (b) the remaining column-bottom liquid
is discharged; and (c) an additive component is added for
replenishment in an amount corresponding to the amount of the
column-bottom liquid to be discharged.
10. A distillation method employing a distillation apparatus
according to claim 7, wherein (a) all of the column-bottom liquid
is fed to said evaporator; and (b) in order to start operation of
said distillation apparatus, an additive component is added in a
predetermined amount to the material liquid.
11. A distillation apparatus according to any one of claims 7 to
10, wherein the liquid rich in the high-boiling-point component ia
cooled.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a distillation apparatus
and a distillation method.
[0003] 2. Description of the Related Art
[0004] Conventionally, various kinds of distillation apparatus have
been provided for separating, through distillation, a plurality of
components contained in a material liquid in order to obtain
predetermined components as products.
[0005] For example, in the case of a material liquid containing
three components A, B, and C, in which component A is lower in
boiling point than component B, and component B is lower in boiling
point than component C; i.e., component A is a low-boiling-point
component, component B is a medium-boiling-point component, and
component C is a high-boiling-point component, the following
distillation apparatus is used to separate components A to C of the
material liquid through distillation.
[0006] FIG. 1 conceptually shows a conventional distillation
apparatus.
[0007] In FIG. 1, reference numeral 201 denotes a first
distillation column; reference numeral 202 denotes a second
distillation column; reference numerals 203 and 205 denote
evaporators; and reference numerals 204 and 206 denote condensers.
The first distillation column 201 includes, from top to bottom, a
first section 211, a second section 212, a third section 213, a
fourth section 214, and a fifth section 215. An unillustrated
packing element is disposed in each of the second section 212 and
the fourth section 214, to thereby form an enriching section in the
second section 212 and an exhaust section in the fourth section
214. The second distillation column 202 includes, from top to
bottom, a first section 216, a second section 217, a third section
218, a fourth section 219, and a fifth section 220. An
unillustrated packing element is disposed in each of the second
section 217 and the fourth section 219, to thereby form an
enriching section in the second section 217 and an exhaust section
in the fourth section 219.
[0008] For example, when a material liquid M containing three
components A, B, and C is fed into the third section 213 of the
first distillation column 201, vapor rich in component A is
discharged from the top of the first distillation column 201 and
sent to the condenser 204, where the vapor is condensed into liquid
rich in component A. The liquid rich in component A is discharged
as distillate from the condenser 204. A portion of the distillate
is refluxed as a refluxed liquid into the first distillation column
201, whereas the remaining distillate is discharged to an external
destination.
[0009] Liquid rich in components B and C is discharged as a
column-bottom liquid from the bottom of the first distillation
column 201. A portion of the column-bottom liquid is sent to the
evaporator 203, where the column-bottom liquid is evaporated
through application of heat to become vapor rich in components B
and C. The vapor rich in components B and C is returned to the
first distillation column 201. The remaining column-bottom liquid
is fed into the third section 218 of the second distillation column
202.
[0010] When the column-bottom liquid is fed into the third section
218, vapor rich in component B is discharged from the top of the
second distillation column 202 and sent to the condenser 206, where
the vapor is condensed into liquid rich in component B. The liquid
rich in component B is discharged as distillate from the condenser
206. A portion of the distillate is refluxed into the second
distillation column 202, whereas the remaining distillate is
discharged to an external destination.
[0011] Liquid rich in component C is discharged as a column-bottom
liquid from the bottom of the second distillation column 202. A
portion of the column-bottom liquid is sent to the evaporator 205,
where the column-bottom liquid is evaporated through application of
heat to become vapor rich in component C. The vapor rich in
component C is returned to the second distillation column 202. The
remaining column-bottom liquid is discharged to an external
destination.
[0012] Next will he described a distillation apparatus to be
applied to the case where components B and C are high-melting-point
materials.
[0013] FIG. 2 conceptually shows a conventional distillation
apparatus to be applied to the case where a medium-boiling-point
component and a high-boiling-point component are formed from
respective high-melting-point materials.
[0014] In FIG. 2, symbol M denotes a material liquid containing
three components A to C; reference numeral 201 denotes a first
distillation column; reference numeral 202 denotes a second
distillation column; reference numerals 203 and 205 denote
evaporators; and reference numerals 204 and 206 denote
condensers.
[0015] When the condenser 206 employs ordinary cooling water as
cooling medium for cooling vapor rich in component B discharged
from the top of the second distillation column 202, and the melting
point of component B is higher than the temperature of cooling
water (for example, the melting point of component B is higher than
a cooling water temperature of 30.degree. C. to 35.degree. C.),
vapor rich in component B cannot be condensed before the
temperature of the vapor rises sufficiently high after operation of
the distillation apparatus is started. During that period of time,
the vapor solidifies within the condenser 206; thus, liquid rich in
component B cannot be obtained as distillate.
[0016] In order to prevent the above-mentioned solidification of
the vapor rich in component B within the condenser 206, a cooling
system 225 connected to the condenser 206 uses a cooling medium
heated to a temperature higher than the melting point of component
B, such as hot water, cooling oil, or steam, until a predetermined
period of time elapses after the operation of the distillation
apparatus is started. Distillate is discharged from the condenser
206 to a line L11; a portion of the distillate is refluxed into the
second distillation column 202 through a line L12; and the
remaining distillate is discharged through a line L13. In order to
prevent solidification of the distillate within the lines L11, L12,
and L13, the lines L11 to L13 assume a double-pipe structure.
[0017] Liquid rich in component C, which serves as a column-bottom
liquid, is discharged from the bottom of the second distillation
column 202 to a line L15; a portion of the column-bottom liquid is
sent to the evaporator 205 through a line L16; and the remaining
column-bottom liquid is discharged through a line L17. In order to
prevent solidification of the column-bottom liquid within the lines
L15 to L17 when the temperature of component C is higher than
ambient temperature, the lines L15 to L17 assume a double-pipe
structure. The double-pipe structure includes an inner pipe and an
outer pipe disposed concentrically. Steam serving as a heating
medium is caused to flow through the space between the inner and
outer pipes to thereby prevent solidification of the distillate or
the column-bottom liquid flowing through the inner pipe.
[0018] In order to reduce energy consumed for heating the
column-bottom liquids in the evaporators 203 and 205, preferably
the evaporators 203 and 205 are lowered in temperature. However,
when the evaporators 203 and 205 are lowered in temperature,
evaporation of the column-bottom liquids becomes difficult
accordingly. In order to cope with this problem, vacuum generators
227 and 228 are connected to the condensers 204 and 206,
respectively, so as to establish a negative pressure within the
first and second distillation columns 201 and 202. As a result, the
column-bottom liquids can be readily evaporated. Also, vent gas
generated within the first and second distillation columns 201 and
202 can be drawn out and released into the atmosphere.
[0019] However, when the condenser 206 and the vacuum generator 228
are directly connected, a portion of vapor rich in component B is
mixed with the vent gas and sent from the condenser 206 to the
vacuum generator 228. The vapor solidifies within the vacuum
generator 228, breaking the vacuum generator 228. In order to cope
with this problem, a vent gas treatment apparatus 230 is disposed
between the condenser 206 and the vacuum generator 228 so as to
remove the vapor rich in component B from the vent gas. The vent
gas treatment apparatus 230 includes condensers 231 and 232 for
separating the vent gas and the vapor from each other. Lines L21 to
L23 for connecting the condenser 206 and the condensers 231 and
232, lines L24 to L26 for connecting the condensers 231 and 232 and
the vacuum generator 228, and lines L27 to L29 for draining the
condensers 231 and 232 assume a steam trace pipe structure.
[0020] However, employment of the above-mentioned auxiliary
apparatus causes an increase in area occupied by the distillation
apparatus and an increase in cost.
[0021] FIG. 3 is a view for explaining a conventional cooling
system. Structural features similar to those in FIG. 2 are denoted
by common reference numerals, and repeated description thereof is
omitted.
[0022] Vapor rich in component B discharged from the second
distillation column 202 is sent, through a line L31, to the
condenser 206, where the vapor is condensed and discharged as a
distillate to a line L11. In order to prevent solidification of the
vapor within the condenser 206, hot water heated to a temperature
higher than the melting point of component B is fed as a cooling
medium to the condenser 206.
[0023] The cooling system 225 includes a hot water tank 235, a
cooler 236, a pump 237, and valves 238 and 239. Before operation of
the distillation apparatus is started, the valve 238 is opened so
as to feed cooling water to the hot water tank 235 through an
unillustrated line and a line L32 such that the hot water tank 235
stores cooling water by a volume required to start up the cooling
system 225; i.e., by a hold up volume. For a predetermined period
of time after operation of the distillation apparatus is started,
the valve 238 is held open to feed steam to the hot water tank 235
through the line L32.
[0024] Water contained in the hot water tank 235 is heated to a
temperature higher than the melting point of component B by means
of the steam. Thus-obtained hot water is sent to the cooler 236 via
a line L36, the pump 237, and a line L35. The cooler 236 cools hot
water to a predetermined temperature higher than the melting point
of component B by means of low-temperature water.
Thus-temperature-regulated hot water is fed to the condenser 206
through a line L34 and causes vapor rich in component B to be
condensed within the condenser 206. In this manner, solidification
of the vapor is prevented, and distillate having a temperature
higher than the melting point of component B can be obtained. Hot
water heated at the condenser 206 is sent to the hot water tank 235
through a line L33. The valve 238 is closed when the temperature of
hot water contained in the hot water tank 235 is equal to or higher
than a predetermined temperature; and the value 238 is opened when
the temperature of hot water contained in the hot water tank 235 is
lower than the predetermined temperature.
[0025] As mentioned above, the cooling system 225 requires the hot
water tank 235 and the cooler 236, among other auxiliary apparatus,
resulting in an increase in area occupied by the distillation
apparatus as well as an increase in cost.
[0026] FIG. 4 is a view for explaining another conventional cooling
system. Structural features similar to those in FIG. 3 are denoted
by common reference numerals, and repeated description thereof is
omitted.
[0027] In order to prevent solidification of vapor rich in
component B within the condenser 206, cooling oil heated to a
temperature higher than the melting point of component B is fed as
a cooling medium to the condenser 206.
[0028] A cooling system 241 includes an oil tank 242, a cooler 236,
a pump 237, and valves 238 and 239. Before operation of the
distillation apparatus is started, the valve 238 is opened so as to
feed cooling oil heated to a temperature higher than the melting
point of component B to the oil tank 242 through a line L32 such
that the oil tank 242 stores cooling oil by the hold up volume of
the cooling system 241. Cooling oil is sent from the oil tank 242
to the cooler 236 via a line L36, the pump 237, and a line L35. The
cooler 236 cools cooling oil to a predetermined temperature higher
than the melting point of component B by means of low-temperature
water. Thus-temperature-regulated cooling oil is fed to the
condenser 206 through a line L34 and causes vapor rich in component
B to be condensed within the condenser 206.
[0029] In the manner mentioned above, solidification of vapor rich
in component B is prevented, and distillate having a temperature
higher than the melting point of component B can be obtained.
Cooling oil heated at the condenser 206 is sent to the oil tank 242
through a line L33. The valve 238 is closed when the temperature of
cooling oil contained in the oil tank 242 is equal to or higher
than a predetermined temperature; and the value 238 is opened when
the temperature of cooling oil contained in the oil tank 242 is
lower than the predetermined temperature.
[0030] As mentioned above, the cooling system 241 requires the
cooler 236 and the oil tank 242, among other auxiliary apparatus,
resulting in an increase in area occupied by the distillation
apparatus as well as an increase in cost.
[0031] FIG. 5 is a view for explaining still another conventional
cooling system.
[0032] In FIG. 5, reference numeral 252 denotes a second
distillation column, and reference numeral 256 denotes a condenser
disposed within the distillation column 252. In order to prevent
solidification of vapor rich in component B within the condenser
256, hot water heated to a temperature higher than the melting
point of component B is fed as a cooling medium to the condenser
256.
[0033] A cooling system 261 includes a hot water tank 262 and
valves 263 to 266. For a predetermined period of time after
operation of the distillation apparatus is started, the valve 263
is held open to feed steam to the hot water tank 262 through a line
L41. In the hot water tank 262, steam and hot water are separated
from each other. Hot water heated to a temperature higher than the
melting point of component B is fed to the condenser 256 through a
line L42 and causes vapor rich in component B to be condensed
within the condenser 256. In this manner, solidification of the
vapor is prevented, and distillate having a temperature higher than
the melting point of component B can be obtained. Hot water
(purified water) heated in the condenser 256 becomes pressurized
hot water corresponding to the temperature of process steam within
the condenser 256. Pressurized hot water is sent to the hot water
tank 262 through a line L43. During the above-mentioned operation,
the valves 264 to 266 are held closed.
[0034] When the distillation apparatus enters steady-state
operation, pressurized hot water fed to the hot water tank 262 is
caused to separate into steam and hot water. Subsequently, the
valve 263 is closed, and the valves 264 to 266 are opened. As a
result, purified water is fed to the hot water tank 262 through a
line L44, and hot water contained in the hot water tank 262 is fed
to the condenser 256 through the line L42. Steam contained in the
hot water tank 262 is discharged through a line L45 and the valve
265. Hot water contained in the hot water tank 262 is periodically
blown out through a line L46 and the valve 266. Through practice of
hot-water blow, the interior of the cooling system 261 is
cleaned.
[0035] As mentioned above, the cooling system 261 requires the hot
water tank 262 and the valves 263 to 266, among other auxiliary
apparatus, resulting in an increase in area occupied by the
distillation apparatus as well as an increase in cost.
[0036] FIG. 6 is a view for explaining a conventional vent gas
treatment apparatus. Structural features similar to those in FIG. 2
are denoted by common reference numerals, and repeated description
thereof is omitted.
[0037] A vent gas treatment apparatus 230 employs
switching-condenser operation. The condenser 206 is accompanied by
two condensers 231 and 232, which are disposed in parallel. One of
the two condensers 231 and 232; for example, the condenser 231 is
operated, while the other condenser 232 is on standby. Coolant is
fed to the operating condenser 231 so as to cool vapor rich in
component B mixed with vent gas to a temperature lower than the
melting point of component B. The vapor is solidified to become a
solid substance rich in component B within the condenser 231.
[0038] Solidification mentioned above causes reduction in the heat
transfer area of the condenser 231. When the heat transfer area
becomes smaller than a predetermined limit, the condenser 231 is
brought on standby, and the condenser 232 is started. Compressed
air is fed to the condenser 231 to thereby blow out coolant
remaining in condenser tubes. Subsequently, steam is fed to the
condenser 231 to thereby melt the solid substance rich in component
B formed within the condenser 231 into liquid rich in component B.
The liquid is discharged through a line L28. Steam is condensed to
become condensate, which is discharged from the condenser 231.
After the liquid rich in component B is discharged from the
condenser 231, coolant is fed to the condenser 231 so as to precool
the same.
[0039] As mentioned above, the vent gas treatment apparatus 230
requires the condensers 231 and 232, among other auxiliary
apparatus, resulting in an increase in area occupied by the
distillation apparatus as well as an increase in cost.
[0040] FIG. 7 is a view for explaining another conventional vent
gas treatment apparatus.
[0041] The condenser 206 and a vent gas treatment apparatus 270 are
connected by means of a line L71. The vacuum generator 228 and the
vent gas treatment apparatus 270 are connected by means of a line
L74. The vent gas treatment apparatus 270 employs vent scrubber
operation. The vent gas treatment apparatus 270 includes a vent
scrubber 271; a pump 273; a heat exchanger 274; and valves 275 and
276. The vent scrubber 271 includes a still section 281 and a
packing column section 282.
[0042] Solution for adsorbing vent gas and vapor rich in component
B is circulated by means of the pump 273. Specifically, the
solution discharged from the still section 281 to a line L72 is
sent, through a line L73, to the heat exchanger 274 by means of the
pump 273. The solution discharged from the heat exchanger 274 is
fed to the packing column section 282 through a line L77. The
thus-fed solution is sprayed from the top of the packing column
section 282 and descends within the packing column section 282.
Vent gas is fed to the still section 281 through the line L71 and
ascends within the packing column section 282 to thereby be
adsorbed by the solution. The solution which has adsorbed vent gas
is discharged to the line L72 and is then sent to an unillustrated
treatment apparatus through a line L75 at predetermined timing. A
line L76 is used to replenish the vent gas treatment apparatus 270
with the solution. The solution has properties capable of
sufficiently adsorbing vapor rich in component B having high
melting point.
[0043] As mentioned above, the vent gas treatment apparatus 270
requires the vent scrubber 271 and the heat exchanger 274, among
other auxiliary apparatus, resulting in an increase in area
occupied by the distillation apparatus as well as an increase in
cost. Furthermore, the solution must has properties capable of
sufficiently adsorbing vapor rich in component B having high
melting point, thus boosting distillation cost.
[0044] A distillation apparatus embodied through modification of
the distillation apparatus of FIG. 1 has been provided. The
distillation apparatus is configured in the following manner. The
top of the first distillation column 201 is connected to the side
of the second distillation column 202. In the first distillation
column 201, component C is separated from components A and B. In
the second distillation column 202, component A and component B are
separated from each other to thereby collect component B as a
product.
[0045] FIG. 8 conceptually shows a conventional distillation
apparatus in which a medium-boiling-point component is collected at
the bottom of a second distillation column. Structural features
similar to those in FIG. 1 are denoted by common reference
numerals, and repeated description thereof is omitted.
[0046] For example, when a material liquid M containing three
components A, B, and C is fed into the third section 213 of the
first distillation column 201, vapor rich in components A and B is
discharged from the top of the first distillation column 201 and
sent to the condenser 204, where the vapor is condensed into liquid
rich in components A and B. The liquid rich in components A and B
is discharged as distillate from the condenser 204. A portion of
the distillate is refluxed into the first distillation column 201,
whereas the remaining distillate is fed into the third section 218
of the second distillation column 202.
[0047] Liquid rich in component C is discharged as a column-bottom
liquid from the bottom of the first distillation column 201. A
portion of the column-bottom liquid is sent to the evaporator 203,
where the column-bottom liquid is evaporated through application of
heat to become vapor rich in component C. The vapor rich in
component C is returned to the first distillation column 201. The
remaining column-bottom liquid is discharged to an external
destination.
[0048] When the distillate is fed into the third section 218, vapor
rich in component A is discharged from the top of the second
distillation column 202 and sent to the condenser 206, where the
vapor is condensed into liquid rich in component A. The liquid rich
in component A is discharged as distillate from the condenser 206.
A portion of the distillate is refluxed into the second
distillation column 202, whereas the remaining distillate is
discharged to an external destination.
[0049] Liquid rich in component B is discharged as a column-bottom
liquid from the bottom of the second distillation column 202. A
portion of the column-bottom liquid is sent to the evaporator 205,
where the column-bottom liquid is evaporated through application of
heat to become vapor rich in component B. The vapor rich in
component B is returned to the second distillation column 202. The
remaining column-bottom liquid is discharged to an external
destination.
[0050] When separation of component C is insufficient in the first
distillation column 201, component C gathers as an impurity in the
vicinity of the bottom of the second distillation column 202. When
components B and C are heated in the evaporators 203 and 205,
respectively, components B and C are decomposed to form modified
components B' and C' having a high boiling point. Thus, modified
components B' and C' also gather as impurities in the vicinity of
the bottom of the second distillation column 202. As a result,
component B collected as a product contains impurities, such as
component C and modified components B' and C'.
[0051] Component C and modified components B' and C' have large
molecular mass of carbon and thus affect hue and odor of the
product.
[0052] Since the product is collected at the bottom of the second
distillation column 202, the product is exposed to high temperature
induced by the evaporator 205 disposed at the column bottom. As a
result, component B, which is a product, is decomposed to form
modified component B' having a high boiling point, with a resultant
impairment in product quality.
[0053] In order to cope with the above problem, there is provided a
distillation apparatus which collects a product in the form of
vapor, not in the form of liquid.
[0054] FIG. 9 conceptually shows a conventional distillation
apparatus which collects a product in the form of vapor. Structural
features similar to those in FIG. 8 are denoted by common reference
numerals, and repeated description thereof is omitted.
[0055] A second distillation column 202 includes, from top to
bottom, a first section 216, a second section 217, a third section
218, a fourth section 219, a fifth section 331, a sixth section
332, and a seventh section 333. A packing element is disposed in
each of the second section 217 and the fourth section 219, to
thereby form an enriching section in the second section 217 and an
exhaust section in the fourth section 219. A demister is disposed
in the sixth section 332.
[0056] Vapor rich in component B is collected as a product from the
fifth section 331 and fed to a condenser 336 via a valve 335. In
the condenser 336, the vapor is condensed into liquid rich in
component B. The liquid rich in component B is discharged from the
condenser 336 as a column-bottom liquid. The liquid is fed to a
receiver 337 and accumulated therein. The liquid is then discharged
from the receiver 337.
[0057] In order to carry out distillation in a low-temperature
region for prevention of impairment in product quality and to
reduce energy consumed for heating a portion of a column-bottom
liquid in evaporators 203 and 205, a vacuum generator 338 is
disposed for use with the condensers 204 and 206, and a vacuum
generator 339 is disposed for use with the condenser 336. The
vacuum generators 338 and 339 generate a negative pressure within
the first and second distillation columns 201 and 202. Thus, the
column-bottom liquids can be readily evaporated. Also, vent gas
generated within the first and second distillation columns 201 and
202 can be drawn out and released into the atmosphere.
[0058] Even though impurities gather in the vicinity of the bottom
of the second distillation column 202, vapor rich in component B is
not collected from the bottom of the second distillation column
202, but is collected as a product from the fifth section 331.
Thus, the product does not contain impurities; therefore, the hue
and odor of the product are not affected. The product is collected
from the fifth section 331; i.e., the product is not exposed to
high temperature induced by the evaporator 205 disposed at the
column bottom, thereby enhancing product quality. Impurities
gathering in the vicinity of the bottom of the second distillation
column 202 are discharged through a line L240.
[0059] There has been provided a distillation apparatus in which a
product is collected in the form of liquid, and impurities are
removed from the product.
[0060] FIG. 10 conceptually shows a conventional distillation
apparatus in which impurities are removed from a product.
Structural features similar to those in FIGS. 8 and 9 are denoted
by common reference numerals, and repeated description thereof is
omitted.
[0061] Liquid rich in component B is collected from the fifth
section 220 as a column-bottom liquid and as a product and fed to a
receiver 342 via a valve 341. The receiver 342 and a heater 344 are
connected. The product fed to the receiver 342 is then fed to the
heater 344, where the product is evaporated to become vapor rich in
component B. In the heater 344, the vapor rich in component B is
separated from impurities, such as component C and modified
components B' and C'. The vapor rich in component B, which is free
of impurities, is returned to the receiver 342.
[0062] Subsequently, the vapor rich in component B is fed to a
condenser 343 for use with a product. In the condenser 343, the
vapor is condensed into liquid rich in component B. The liquid rich
in component B is discharged from the condenser 343. The liquid is
fed to a receiver 345 and accumulated therein. Then, the liquid is
discharged from the receiver 345 and sent to an external
destination via a valve 346. In the course of operation mentioned
above, impurities are accumulated within the receiver 342. Thus,
when the operation is performed for a predetermined period of time,
the impurities are removed through a line L248. Reference numeral
347 denotes a vacuum generator.
[0063] The above-mentioned conventional distillation apparatus
adapted to collect a product in the form of vapor requires the
valve 335, the condenser 336, and the receiver 337, among other
auxiliary apparatus. The above-mentioned conventional distillation
apparatus adapted to collect a product in the form of liquid and
adapted to remove impurities from the product requires the valves
341 and 346, the receivers 342 and 345, the condenser 343, and the
heater 344, among other auxiliary apparatus. Thus, the size and
cost of the distillation apparatus increase.
[0064] Also, the distillation apparatus require complicated
equipment for controlling and maintaining the same. In particular,
in the case of the distillation apparatus adapted to collect a
product in the form of vapor, the flow rate of vapor discharged
from the fifth section 331 must be regulated by means of the valve
335. However, since control of vapor is very complicated,
involvement of vapor control pushes up the cost of the distillation
apparatus.
SUMMARY OF THE INVENTION
[0065] An object of the present invention is to solve the
above-mentioned problems in the conventional distillation apparatus
and to provide a distillation apparatus which allows a reduction in
area occupied thereby and which can be manufactured and operated at
low cost, as well as to provide a distillation method employing the
distillation apparatus.
[0066] Another object of the present invention is to provide a
distillation apparatus enabling removal of impurities from a
product to thereby prevent adverse effect on hue and odor of the
product which would otherwise result from the impurities, as well
as to provide a distillation method employing the distillation
apparatus.
[0067] To achieve the above objects, the present invention provides
a distillation apparatus comprising a column body; a partition for
dividing the interior of the column body into a first chamber and a
second chamber, which are adjacent to each other; a first
distillation section having an enriching section, to which a
material liquid is fed through a feed nozzle and which is formed
above the feed nozzle, and an exhaust section formed under the feed
nozzle; a second distillation section having an enriching section
connected to and formed above an upper end of the first
distillation section, and an exhaust section formed below the upper
end and located adjacent to the enriching section of the first
distillation section while being separated from the same by the
partition; a third distillation section having an enriching section
connected to and formed above a lower end of the first distillation
section, and located adjacent to the exhaust section of the first
distillation section while being separated from the same by the
partition, and an exhaust section formed below the lower end; a
condenser connected to the top of the column body and adapted to
condense vapor rich in a low-boiling-point component discharged at
the top; negative-pressure generation means connected to the
condenser and adapted to generate a negative pressure to thereby
withdraw vent gas from the column body; a gas cooler for cooling
the vent gas disposed between the condenser and the
negative-pressure generation means; a first discharge system
disposed at the side of the column body and adapted to discharge
liquid rich in a medium-boiling-point component formed from a
high-melting-point material; and a second discharge system disposed
at the bottom of the column body and adapted to discharge liquid
rich in a high-boiling-point component formed from a
high-melting-point material.
[0068] The first discharge system has first solidification
prevention means for preventing solidification of the liquid rich
in the medium-boiling-point component. The second discharge system
has second solidification prevention means for preventing
solidification of the liquid rich in the high-boiling-point
component.
[0069] In this case, the vapor rich in the low-boiling-point
component is discharged at the top of the column body, and the
low-boiling-point component is formed from a low-melting-point
material. Thus, there is no need to employ various auxiliary
apparatus such as a hot water tank, a cooler, an oil tank, a
condenser, and a vent scrubber.
[0070] Thus, the distillation apparatus allows a reduction in area
occupied thereby and can be manufactured and operated at low
cost.
[0071] Preferably, the first and second solidification prevention
means each assume a double-pipe structure comprising an inner pipe
and an outer pipe disposed concentrically and in which a heating
medium is caused to flow through the space between the inner and
outer pipes to thereby prevent solidification of the liquid flowing
through the inner pipe.
[0072] Further preferably, the first and second solidification
prevention means are each steam tracing comprising a primary pipe
and a secondary pipe disposed in parallel and in which a heating
medium is caused to flow through the secondary pipe to thereby
prevent solidification of the liquid flowing through the primary
pipe.
[0073] The present invention provides another distillation
apparatus comprising a column body; a partition for dividing the
interior of the column body into a first chamber and a second
chamber, which are adjacent to each other; a first distillation
section having an enriching section, to which a material liquid
containing a low-boiling-point component, a medium-boiling-point
component, and a high-boiling-point component is fed through a feed
nozzle and which is formed above the feed nozzle, and an exhaust
section formed under the feed nozzle; a second distillation section
having an enriching section connected to and formed above an upper
end of the first distillation section, and an exhaust section
formed below the upper end and located adjacent to the enriching
section of the first distillation section while being separated
from the same by the partition; a third distillation section having
an enriching section connected to and formed above a lower end of
the first distillation section, and located adjacent to the exhaust
section of the first distillation section while being separated
from the same by the partition, and an exhaust section formed below
the lower end; a condenser connected to the top of the column body
and adapted to condense vapor rich in a low-boiling-point component
discharged at the top; a side cut nozzle disposed at the side of
the column body and adapted to discharge liquid rich in the
medium-boiling-point component as a product at the side; an
evaporator disposed at the bottom of the column body and adapted to
generate vapor through application of heat to liquid rich in a
high-boiling-point component discharged at the bottom; and a cooler
connected to the side cut nozzle and adapted to cool the
product.
[0074] In this case, the liquid rich in the medium-boiling point
component is enriched in the exhaust section of the second
distillation section and discharged as a product at the side of the
column body. The liquid rich in the high-boiling-point component is
enriched in the exhaust section of the first distillation section
and in the enriching section of the third distillation section. The
thus-enriched liquid rich in the high-boiling-point component is
further enriched in the exhaust section of the third distillation
section and is then discharged at the bottom of the column body. A
modified component formed through decomposition of the
medium-boiling-point component is collected in the vicinity of the
bottom of the column body and is then discharged at the column
bottom.
[0075] Accordingly, the medium-boiling-point component does not
contact the high-boiling-point component and the modified component
while these components are in the form of liquid. Thus, the
medium-boiling-point component collected as a product does not
contain the high-boiling-point component and the modified
component, which are impurities. As a result, the hue and odor of
the product are not affected.
[0076] Also, entry of impurities into a product can be prevented
without use of auxiliary apparatus such as a valve, a product
condenser, a receiver, and a heater, thereby reducing the size of
the distillation apparatus and the cost of manufacture and
operation of the distillation apparatus. Furthermore, there can be
simplified equipment for controlling the operation of the
distillation apparatus and maintaining the distillation apparatus.
Since a product can be collected in the form of liquid, flow rate
control of the product can be significantly simplified, thereby
reducing the cost of manufacture and operation of the distillation
apparatus.
[0077] Since a product is collected at the side of the column body,
the product is not exposed to high temperature induced by the
evaporator disposed at the bottom of the column body. Also, the
product does not require additional heating by a heater. Thus,
formation of a modified component within the product can be
prevented, thereby enhancing product quality.
[0078] The product collected at the side of the column body is
immediately cooled by the cooler, thereby preventing decomposition
of the medium-boiling-point component which would otherwise result
from heat held by the product itself. Formation of a modified
component within the product can be prevented more reliably.
[0079] The present invention provides a further distillation
apparatus comprising: a column body; a partition for dividing the
interior of the column body into a first chamber and a second
chamber, which are adjacent to each other; a first distillation
section having an enriching section, to which an adjusted material
liquid comprising a material liquid and an additive component is
fed through a feed nozzle and which is formed above the feed
nozzle, and an exhaust section formed under the feed nozzle; a
second distillation section having an enriching section connected
to and formed above an upper end of the first distillation section,
and an exhaust section formed below the upper end and located
adjacent to the enriching section of the first distillation section
while being separated from the same by the partition; a third
distillation section having an enriching section connected to and
formed above a lower end of the first distillation section, and
located adjacent to the exhaust section of the first distillation
section while being separated from the same by the partition, and
an exhaust section formed below the lower end; a condenser disposed
at the top of the column body and adapted to condense vapor rich in
the additive component into liquid rich in the additive component
and to discharge the liquid rich in the additive component as
distillate; a first discharge system disposed at the side of the
column body and adapted to discharge liquid rich in a
low-boiling-point component formed from a high-melting-point
material; and a second discharge system disposed at the bottom of
the column body and adapted to discharge liquid rich in a
high-boiling-point component.
[0080] The boiling point of the additive component is lower than
that of the low-boiling-point component.
[0081] In this case, the adjusted material liquid is obtained
through addition, to a material liquid, of an additive component
lower in boiling point than the low-boiling-point component. The
adjusted material liquid is fed to the first distillation section
through the feed nozzle. Thus, vapor rich in the additive component
is discharged from the top of the column body. There is no need to
collect the low-boiling-point component as a product at the top of
the column body. Vapor rich in the additive component is condensed
by means of the condenser; i.e., there is no need to condense vapor
rich in the low-boiling-point component by means of the
condenser.
[0082] Thus, there is no need to employ various auxiliary apparatus
such as a hot water tank, a cooler, an oil tank, a condenser, a
vent scrubber, and a heat exchanger, thereby reducing the size of
the distillation apparatus and the cost of manufacture and
operation of the distillation apparatus.
[0083] Preferably, a portion of the distillate is refluxed into the
column body, and the remaining distillate is added as an additive
component to the material liquid.
[0084] In this case, the additive component can be repeatedly used
through addition to the material liquid, thereby reducing the cost
of operation of the distillation apparatus.
[0085] Further preferably, a portion of the distillate is refluxed
into the column body; the remaining distillate is discharged; and
an additive component is added for replenishment in an amount
corresponding to the amount of the distillate to be discharged.
[0086] Still further preferably, all of the distillate is refluxed
into the column body; and in order to start operation of the
distillation apparatus, an additive component is added in a
predetermined amount to the material liquid.
[0087] Still further preferably, the distillation apparatus further
comprises negative-pressure generation means connected to the
condenser and adapted to generate a negative pressure to thereby
withdraw vent gas from the column body; and a gas cooler for
cooling the vent gas disposed between the condenser and the
negative-pressure generation means.
[0088] Still further preferably, the first discharge system has
solidification prevention means for preventing solidification of
the liquid rich in the low-boiling-point component.
[0089] The present invention provides a distillation method
applicable to a distillation apparatus comprising a column body; a
partition for dividing the interior of the column body into a first
chamber and a second chamber, which are adjacent to each other; a
first distillation section having an enriching section formed above
a feed nozzle, and an exhaust section formed under the feed nozzle;
a second distillation section having an enriching section connected
to and formed above an upper end of the first distillation section,
and an exhaust section formed below the upper end and located
adjacent to the enriching section of the first distillation section
while being separated from the same by the partition; and a third
distillation section having an enriching section connected to and
formed above a lower end of the first distillation section, and
located adjacent to the exhaust section of the first distillation
section while being separated from the same by the partition, and
an exhaust section formed below the lower end.
[0090] The distillation method comprises the steps of feeding an
adjusted material liquid comprising a material liquid and an
additive component to the first distillation section through the
feed nozzle; condensing vapor rich in the additive component into
liquid rich in the additive component at the top of the column
body; discharging the liquid rich in the additive component as
distillate; discharging liquid rich in a low-boiling-point
component formed from a high-melting-point material at the side of
the column body; and discharging liquid rich in a
high-boiling-point component at the bottom of the column body.
[0091] The boiling point of the additive component is lower than
that of the low-boiling-point component.
[0092] The present invention provides a further distillation
apparatus comprising a column body; a partition for dividing the
interior of the column body into a first chamber and a second
chamber, which are adjacent to each other; a first distillation
section having an enriching section, to which an adjusted material
liquid comprising a material liquid and an additive component is
fed through a feed nozzle and which is formed above the feed
nozzle, and an exhaust section formed under the feed nozzle; a
second distillation section having an enriching section connected
to and formed above an upper end of the first distillation section,
and an exhaust section formed below the upper end and located
adjacent to the enriching section of the first distillation section
while being separated from the same by the partition; a third
distillation section having an enriching section connected to and
formed above a lower end of the first distillation section, and
located adjacent to the exhaust section of the first distillation
section while being separated from the same by the partition, and
an exhaust section formed below the lower end; a condenser disposed
at the top of the column body and adapted to condense vapor rich in
a low-boiling-point component into liquid rich in the
low-boiling-point component and to discharge the liquid rich in the
low-boiling-point; a first discharge system disposed at the side of
the column body and adapted to discharge liquid rich in a
high-boiling-point component; a second discharge system disposed at
the bottom of the column body and adapted to discharge liquid rich
in the additive component as a column-bottom liquid; and an
evaporator for evaporating the column-bottom liquid to thereby
obtain vapor rich in the additive component.
[0093] The boiling point of the additive component is higher than
that of the high-boiling-point component.
[0094] In this case, since a modified component formed through
decomposition of the high-boiling point component gathers in the
vicinity of the bottom of the column body, the modified component
and the high-boiling-point component do not contact each other
while these components are in the form of liquid. Thus, the product
to be collected does not contain the modified component, which is
an impurity. As a result, the hue and odor of the product are not
affected.
[0095] Also, entry of impurities into a product can be prevented
without use of auxiliary apparatus such as a valve, a product
condenser, a receiver, and a heater, thereby reducing the size of
the distillation apparatus and the cost of manufacture and
operation of the distillation apparatus. Furthermore, there can be
simplified equipment for controlling the operation of the
distillation apparatus and maintaining the distillation apparatus.
Since a product can be collected in the form of liquid, flow rate
control of the product can be significantly simplified, thereby
reducing the cost of manufacture and operation of the distillation
apparatus.
[0096] Since a product is collected at the side of the column body
the product is not exposed to high temperature induced by the
evaporator disposed in the vicinity of the bottom of the column
body. Also, the product does not require additional heating by a
heater. Thus, formation of a modified component, which becomes an
impurity, within the product can be prevented, thereby enhancing
product quality.
[0097] Preferably, a portion of the column-bottom liquid is fed to
the evaporator; and the remaining column-bottom liquid is added as
an additive component to the material liquid.
[0098] In this case, the additive component can be repeatedly used
through addition to the material liquid, thereby reducing the cost
of operation of the distillation apparatus.
[0099] Further preferably, most of the column-bottom liquid is fed
to the evaporator; the remaining column-bottom liquid is
discharged; and an additive component is added for replenishment in
an amount corresponding to the amount of the column-bottom liquid
to be discharged.
[0100] Still further preferably, all of the column-bottom liquid is
fed to the evaporator; and in order to start operation of the
distillation apparatus, an additive component is added in a
predetermined amount to the material liquid.
[0101] Still further preferably, the first discharge system has
cooling means for cooling the liquid rich in the high-boiling-point
component.
[0102] In this case, the product collected at the side of the
column body is immediately cooled by the cooling means, thereby
preventing decomposition of the high-boiling-point component which
would otherwise result from heat held by the product itself.
Formation of a modified component within the product can be
prevented.
[0103] The present invention provides another distillation method
applicable to a distillation apparatus comprising a column body; a
partition for dividing the interior of the column body into a first
chamber and a second chamber, which are adjacent to each other; a
first distillation section having an enriching section formed above
a feed nozzle, and an exhaust section formed under the feed nozzle;
a second distillation section having an enriching section connected
to and formed above an upper end of the first distillation section,
and an exhaust section formed below the upper end and located
adjacent to the enriching section of the first distillation section
while being separated from the same by the partition; and a third
distillation section having an enriching section connected to and
formed above a lower end of the first distillation section, and
located adjacent to the exhaust section of the first distillation
section while being separated from the same by the partition, and
an exhaust section formed below the lower end.
[0104] The distillation method comprises the steps of feeding an
adjusted material liquid comprising a material liquid and an
additive component to the first distillation section through the
feed nozzle; condensing vapor rich in a low-boiling-point component
into liquid rich in the low-boiling-point component at the top of
the column body; discharging the liquid rich in the
low-boiling-point component at the top of the column body;
discharging liquid rich in a high-boiling-point component at the
side of the column body; discharging liquid rich in the additive
component as a column-bottom liquid at the bottom of the column
body; and evaporating the column-bottom liquid to thereby obtain
vapor rich in the additive component.
[0105] The boiling point of the additive component is higher than
that of the high-boiling-point component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0106] The structure and features of the distillation apparatus and
method according to the present invention will be readily
appreciated as the same becomes better understood by referring to
the drawings, in which:
[0107] FIG. 1 is a conceptual view of a conventional distillation
apparatus;
[0108] FIG. 2 is a conceptual view of a conventional distillation
apparatus to be applied to the case where a medium-boiling-point
component and a high-boiling-point component are formed from
respective high-melting-point materials;
[0109] FIG. 3 is a view for explaining a conventional cooling
system;
[0110] FIG. 4 is a view for explaining another conventional cooling
system;
[0111] FIG. 5 is a view for explaining still another conventional
cooling system;
[0112] FIG. 6 is a view for explaining a conventional vent gas
treatment apparatus;
[0113] FIG. 7 is a view for explaining another conventional vent
gas treatment apparatus;
[0114] FIG. 8 is a conceptual view of a conventional distillation
apparatus in which a medium-boiling-point component is collected at
the bottom of a second distillation column;
[0115] FIG. 9 is a conceptual view of a conventional distillation
apparatus which collects a product in the form of vapor;
[0116] FIG. 10 is a conceptual view of a conventional distillation
apparatus in which impurities are removed from a product;
[0117] FIG. 11 is a conceptual view of a distillation apparatus
according to a first embodiment of the present invention;
[0118] FIG. 12 is a conceptual view of a coupling-type distillation
column used in the distillation apparatus of the first
embodiment;
[0119] FIG. 13 is a conceptual view of a distillation apparatus
according to a second embodiment of the present invention;
[0120] FIG. 14 is a conceptual view of a distillation apparatus
according to a third embodiment of the present invention;
[0121] FIG. 15 is a conceptual view of a coupling-type distillation
column used in the distillation apparatus of the third
embodiment;
[0122] FIG. 16 is a conceptual view of a distillation apparatus
according to a fourth embodiment of the present invention;
[0123] FIG. 17 is a conceptual view of a distillation apparatus
according to a fifth embodiment of the present invention;
[0124] FIG. 18 is a conceptual view of a distillation apparatus
according to a sixth embodiment of the present invention;
[0125] FIG. 19 is a conceptual view of a coupling-type distillation
column used in the distillation apparatus of the sixth
embodiment;
[0126] FIG. 20 is a conceptual view of a distillation apparatus
according to a seventh embodiment of the present invention;
[0127] FIG. 21 is a conceptual view of a distillation apparatus
according to an eighth embodiment of the present invention;
[0128] FIG. 22 is a conceptual view of a main portion of a
distillation apparatus according to a ninth embodiment of the
present invention; and
[0129] FIG. 23 is a conceptual view of a main portion of a
distillation apparatus according to a tenth embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0130] Embodiments of the present invention will next be described
in detail with reference to the drawings.
[0131] FIG. 11 conceptually shows a distillation apparatus
according to a first embodiment of the present invention. FIG. 12
conceptually shows a coupling-type distillation column used in the
distillation apparatus of the first embodiment.
[0132] In the drawings, reference numeral 10 denotes a
coupling-type distillation column. The coupling-type distillation
column 10 includes a first section 11, a second section 12, a third
section 13, a fourth section 14, a fifth section 15, a sixth
section 16, a seventh section 17, an eighth section 18, and a ninth
section 19.
[0133] In a column body of the coupling-type distillation column
10, a partition 22 divides the fourth section 14 into a first
chamber 14A and a second chamber 14B; a partition 23 divides the
fifth section 15 into a first chamber 15A and a second chamber 15B;
and a partition 24 divides the sixth section 16 into a first
chamber 16A and a second chamber 16B. The first chambers 14A-16A
are adjacent to the second chambers 14B-16B, respectively. The
first chambers 14A-16A constitute a first distillation section 25;
the first section 11, the second section 12, the third section 13,
and the second chamber 14B constitute a second distillation section
26; and the second chambers 15B and 16B, the seventh section 17,
the eighth section 18, and the ninth section 19 constitute a third
distillation section 27.
[0134] Notably, the partitions 22-24 can be made heat insulating
through employment of a design such that the partitions 22-24 are
formed of an insulating material or a design such that the
interiors of the partitions 22-24 are made vacuum. In this case,
since there can be reduced heat transmission between the first
chamber 14A and the second chamber 14B, between the first chamber
15A and the second chamber 15B, and between the first chamber 16A
and the second chamber 16B, the efficiency of distillation can be
enhanced.
[0135] The fifth section 15 is disposed substantially at the
vertical center of the coupling-type distillation column 10. A feed
nozzle 41 is formed on the side of the coupling-type distillation
column 10 at a position corresponding to the first chamber 15A.
Similarly, a side cut nozzle 42 is formed on the side of the
coupling-type distillation column 10 at a position corresponding to
the second chamber 15B. The first section 11 is disposed at the top
of the coupling-type distillation column 10. A vapor outlet 43 and
a reflux liquid inlet 44, which are connected to a condenser 81,
are formed at the first section 11. The ninth section 19 is
disposed at the bottom of the coupling-type distillation column 10.
A column-bottom liquid outlet 45 and a vapor inlet 46, which are
connected to an evaporator 82, are formed at the ninth section
19.
[0136] In the thus-configured coupling-type distillation column 10,
a material liquid M containing three components A, B, and C is fed
to the feed nozzle 41 through a line L51. Component A is lower in
boiling point than component B, which in turn is lower in boiling
point than component C. Component A serves as a low-boiling-point
component; component B serves as a medium-boiling-point component;
and component C serves as a high-boiling-point component.
Components B and C are formed from respective high-melting-point
materials.
[0137] In the first distillation section 25, the first chamber 14A
disposed above the feed nozzle 41 forms an enriching section AR1,
and the first chamber 16A disposed below the feed nozzle 41 forms
an exhaust section AR2. In the second distillation section 26, the
second section 12 connected to and disposed above the upper end of
the first distillation section 25 forms an enriching section AR3,
and the second chamber 14B disposed below the upper end of the
first distillation section 25 while being adjacent to the enriching
section AR1 forms an exhaust section AR4. In the third distillation
section 27, the second chamber 16B connected to and disposed above
the lower end of the first distillation section 25 while being
adjacent to the exhaust section AR2 forms an enriching section AR5,
and the eighth section 18 disposed below the lower end of the first
distillation section 25 forms an exhaust section AR6.
[0138] As described above, the upper end of the first distillation
section 25 is connected to the substantial vertical center of the
second distillation section 26, and the lower end of the first
distillation section 25 is connected to the substantial vertical
center of the third distillation section 27.
[0139] In the exhaust section AR2, the material liquid M fed
through the feed nozzle 41 undergoes vapor-liquid separation such
that vapor rich in components A and B is generated at an upper
portion thereof, while fluid composed of vapor and liquid rich in
components B and C is increasingly generated along the descending
direction. The fluid is fed to the third distillation section 27
from the lower end of the first distillation section 25.
[0140] The fluid is heated in the third distillation section 27 to
thereby become vapor rich in components B and C. During ascending
in the exhaust section AR2, the vapor rich in components B and C
contacts the material liquid M. As a result, component A contained
in the material liquid M is prevented from descending and is thus
collected. Thus is prevented entry of component A into the third
distillation section 27.
[0141] The vapor rich in components A and B ascends in the
enriching section AR1 and is then fed to the second distillation
section 26 from the upper end of the first distillation section 25.
The vapor rich in components A and B is cooled in the second
distillation section 26 to thereby be condensed into liquid rich in
components A and B.
[0142] A portion of the liquid rich in components A and B is
refluxed to the enriching section AR1 and brought into contact with
the vapor rich in components A and B Which is ascending in the
enriching section AR1.
[0143] In this manner, the vapor rich in components A and B can be
fed to the second distillation section 26 from the upper end of the
first distillation section 25.
[0144] In the exhaust section AR6, liquid rich in components B and
C descends, during which vapor rich in component B is generated at
an upper portion thereof, and liquid rich in component C is
increasingly generated along the descending direction. The liquid
rich in component C is discharged as a column-bottom liquid to a
line L52 from the column-bottom liquid outlet 45.
[0145] A portion of the column-bottom liquid is sent to the
evaporator 82 through a line L53. In the evaporator 82, the liquid
is evaporated through application of heat to become vapor rich in
component C. The vapor rich in component C is fed to the vapor
inlet 46 through a line L54 to thereby be fed to the ninth section
19. During ascending in the ninth section 19 and the exhaust
section AR6, the vapor rich in component C contacts liquid rich in
components B and C; as a result, vapor rich in component B is
generated from the liquid rich in components B and C. The remaining
column-bottom liquid is fed to an unillustrated column-bottom
liquid accommodation section through the line L55.
[0146] Then, a portion of the vapor rich in component B ascends in
the enriching section AR5, during which the portion of the vapor
rich in component B contacts the liquid rich in component B from
the second distillation section 26 at the upper end of the third
distillation section 27 to thereby become liquid rich in component
B. The liquid rich in component B obtained at the upper end of the
third distillation section 27 is discharged as a side cut liquid
from the side cut nozzle 42 to a line L56. The discharged side cut
liquid is fed to an unillustrated side cut liquid accommodation
section. The line L56 serves as the first discharge system.
[0147] In the exhaust section AR4 of the second distillation
section 26, liquid rich in components A and B descends, during
which vapor rich in component A is generated at an upper portion
thereof, and liquid rich in component B is increasingly generated
along the descending direction. The liquid rich in component B
obtained at the lower end of the second distillation section 26 is
discharged as the side cut liquid from the side cut nozzle 42 to
the line L56.
[0148] The vapor rich in component A ascends in the enriching
section AR3 and is then discharged from the vapor outlet 43 to a
line L57. The discharged vapor rich in component A is sent to the
condenser 81, where the vapor is condensed into liquid rich in
component A, which is discharged as distillate to a line L58. In
order to enhance the efficiency of distillation for component A, a
portion of the distillate is sent to the reflux liquid inlet 44
through a line L59 and refluxed into the first section 11 through
the reflux liquid inlet 44. The refluxed distillate is brought into
contact with vapor rich in components A and B ascending in the
enriching section AR3. The remaining distillate is fed to an
unillustrated distillate accommodation section through a line
L60.
[0149] As described above, vapor rich in components A and B is
separated into vapor rich in component A and liquid rich in
component B by means of the second distillation section 26. The
vapor rich in component A is discharged from the top of the column
body and condensed into liquid rich in component A by means of the
condenser 31. The liquid rich in component B is discharged as a
side cut liquid from the side cut nozzle 42. Liquid rich in
components B and C is separated into liquid rich in component B and
liquid rich in component C by means of the third distillation
section 27. The liquid rich in component B is discharged as a side
cut liquid from the side cut nozzle 42. The liquid rich in
component C is discharged as a column-bottom liquid from the bottom
of the column body.
[0150] Since the melting points of components B and C are higher
than ambient temperature, the lines L52, L53, L55, and L56 assume a
double-pipe structure in order to prevent solidification of the
side cut liquid within the line L56 and solidification of the
column-bottom liquid within the lines L52, L53, and L55. The lines
L52, L53, and L55 constitute the second discharge system. The
double-pipe structure that the line L56 assumes serves as the first
solidification prevention means, and the double-pipe structure that
the lines L52, L53, and L55 assume serves as the second
solidification prevention means. The double-pipe structure is
composed of an inner pipe and an outer pipe disposed
concentrically. Steam serving as a heating medium is caused to flow
through the space between the inner and outer pipes to thereby
prevent solidification of the column-bottom liquid or the side cut
liquid flowing through the inner pipe. The present embodiment
employs the double-pipe structure as the first and second
solidification prevention means. However, steam tracing may be
employed in place of the double-pipe structure. Steam tracing is
composed of a primary pipe and a secondary pipe disposed in
parallel. Steam serving as a heating medium is caused to flow
through the secondary pipe to thereby prevent solidification of the
column-bottom liquid or the side cut liquid flowing through the
primary pipe.
[0151] Each of the enriching sections AR1, AR3, and AR5 and the
exhaust sections AR2, AR4, and AR6 is formed of a packing including
a single node. However, depending on relative volatility among
components to be obtained through distillation, each of the
enriching sections AR1, AR3, and AR5 and the exhaust sections AR2,
AR4, and AR6 may be formed of a packing including a plurality of
nodes corresponding to characteristics of a packing to be used, in
order to attain the number of theoretical stages required for
distillation. Also, a distributor may be disposed between the
nodes. Furthermore, the feed nozzle 41 and the side cut nozzle 42
are not necessarily disposed at the same level.
[0152] As described above, through use of the coupling-type
distillation column 10, the material liquid M can be separated into
components A-C without use of a plurality of distillation
columns.
[0153] Since there is no need to repeat heating and cooling in a
plurality of distillation columns, the number of instruments, such
as condensers, evaporators, and pumps, can be reduced. Accordingly,
an area to be occupied by the distillation apparatus can be
reduced, and the amount of consumption of utilities and consumed
energy can be reduced as well, thereby reducing the cost of the
distillation apparatus.
[0154] Preferably, the coupling-type distillation column 10 has a
total of about 30-100 theoretical stages, and about 5-30
theoretical stages are allocated to each of the fourth section 14
and the sixth section 16.
[0155] Meanwhile, the third section 13 includes a collector 54 and
a channel-type distributor 61. Liquid collected by the collector 54
is distributed to the first chamber 14A and the second chamber 14B
of the fourth section 14 in predetermined different portions by
means of the distributor 61.
[0156] The first chamber 15A of the fifth section 15 includes a
collector 62 disposed just above the feed nozzle 41 and a tubular
distributor 63 disposed just under the feed nozzle 41. Liquid
collected by the collector 62, together with the material liquid M
fed through the feed nozzle 41, is fed to the first chamber 16A of
the sixth section 16 by means of the distributor 63.
[0157] Meanwhile, the second chamber 15B of the fifth section 15
includes a chimney-hat-type collector 65 disposed just above the
side cut nozzle 42 and a tubular distributor 66 disposed just under
the side cut nozzle 42. Liquid collected by the collector 65 is
discharged as a side cut liquid from the side cut nozzle 42 and fed
to the second chamber 16B of the sixth section 16 by means of the
distributor 66.
[0158] Furthermore, the seventh section 17 includes a collector 67
and a tubular distributor 68. Liquid descending from the sixth
section 16 is collected by the collector 67 and is then fed to the
eighth section 18 by means of the distributor 68.
[0159] In the present embodiment, when vapor rich in component A
discharged from the top of the column body is condensed by means of
the condenser 81, ordinary cooling water is used as a cooling
medium for cooling the vapor. Since the melting point of component
A is lower than the temperature of cooling water (for example, the
melting point of component A is lower than a cooling water
temperature of 30.degree. C. to 35.degree. C.), the vapor rich in
component A can be sufficiently condensed without involvement of
solidification of the vapor within the condenser 81.
[0160] Accordingly, there is no need to use hot water, cooling oil,
or steam as the cooling medium. As a result, there is no need to
connect a cooling system to the condenser 81.
[0161] In order to reduce energy consumed for heating a
column-bottom liquid in the evaporator 82, preferably the
evaporator 82 is lowered in temperature. However, when the
evaporator 82 is lowered in temperature, evaporation of the
column-bottom liquid becomes difficult accordingly. In order to
cope with this problem, a vacuum generator 91 serving as the
negative-pressure generation means is connected to the condenser
81, so as to establish a negative pressure within the coupling-type
distillation column 10. As a result, the column-bottom liquid can
be readily evaporated. Also, vent gas generated within the
coupling-type distillation column 10 can be drawn out and released
into the atmosphere.
[0162] In this case, a gas cooler 92 is disposed between the
condenser 81 and the vacuum generator 91 in order to cool vent gas
withdrawn by means of the vacuum generator 91. A line L61 connects
the condenser 81 and the gas cooler 92, and a line L62 connects the
gas cooler 92 and the vacuum generator 91. When vent gas mixed with
vapor rich in component A is sent from the condenser 81 to the gas
cooler 92 and cooled in the gas cooler 92, the vapor becomes liquid
rich in component A to thereby be separated from the vent gas.
Thus, there is no need to dispose a vent gas treatment apparatus
between the condenser 81 and the vacuum generator 91. Notably, the
gas cooler 92 can use ordinary cooling water as a cooling medium.
The distillation apparatus of the present embodiment includes the
column body, the partitions 22-24, the first to third distillation
sections 25-27, the condenser 81, the evaporator 82, the vacuum
generator 91, the gas cooler 92, and the lines L52, L53, L55, and
L56.
[0163] As mentioned above, vapor rich in component A is discharged
from the top of the column body, and component A is formed from a
low-melting-point material. Thus, there is no need to employ
various auxiliary apparatus such as a hot water tank, a cooler, an
oil tank, a condenser, and a vent scrubber. Therefore, the
distillation apparatus allows a reduction in area occupied thereby
and can be manufactured and operated at low cost.
[0164] According to the present embodiment, the gas cooler 92 is
disposed between the condenser 81 and the vacuum generator 91.
However, a vent-scrubber-type vent gas treatment apparatus may be
disposed in place of the gas cooler 92. In this case, since
solution to be used is not required to have the capability of
sufficiently adsorbing vapor rich in component A, the cost of
operation of the distillation apparatus can be reduced.
[0165] According to the present embodiment, vapor rich in component
A is discharged from the vapor outlet 43 to the line L57 so as to
be sent to the condenser 81. However, a condenser may be disposed
in the first section of the column body to thereby connect the top
of the column body and the condenser.
[0166] Meanwhile, when component B collected as a product contains
component C and modified components B' and C', which are
impurities, the hue and odor of the product are affected, since
component C and modified components B' and C' each have a large
molecular mass of carbon. A second embodiment of the present
invention, which will be described below, is adapted to prevent
entry of impurities into a product. Structural features similar to
those of the first embodiment are denoted by common reference
numerals, and repeated description thereof is omitted.
[0167] FIG. 13 conceptually shows a distillation apparatus
according to the second embodiment.
[0168] In this case, a portion of vapor rich in component B ascends
in the enriching section AR5 and contacts liquid rich in component
B descending from the second distillation section 26 at the upper
end of the third distillation section 27 to thereby become liquid
rich in component B. In the exhaust section AR4 of the second
distillation section 26, liquid rich in components A and B
descends, during which vapor rich in component A is generated at an
upper portion thereof, and liquid rich in component B is
increasingly generated along the descending direction. The liquid
rich in component B is enriched in the second chamber 15B. The
enriched liquid is discharged as a side cut liquid or a product
from the side of the column body to the line L56 through the side
cut nozzle 42. The discharged side cut liquid is fed to a cooler
192, where the liquid is cooled. The cooled side cut liquid is
discharged to a line L63 and fed through the line L63 to an
unillustrated side cut liquid accommodation section.
[0169] In this case, the liquid rich in component B is enriched in
the second chamber 15B, and the enriched liquid is discharged as a
product from the side of the column body through the side cut
nozzle 42. Meanwhile, liquid rich in component C is enriched in the
first chamber 16A and the second chamber 16B and is further
enriched in the eighth section 18. Subsequently, the enriched
liquid is discharged from the bottom of the column body through the
column-bottom liquid outlet 45. Modified components B' and C'
formed through decomposition of components B and C are collected in
the vicinity of the bottom of the column body and discharged from
the column bottom through the column-bottom liquid outlet 45.
[0170] Thus, component B does not contact component C and modified
components B' and C' while these components are in the form of
liquid. Therefore, the product to be collected does not contain
component C and modified components B' and C', which are
impurities. As a result, the hue and odor of the product are not
affected.
[0171] Also, entry of impurities into the product can be prevented
without use of auxiliary apparatus such as a valve, a product
condenser, a receiver, and a heater, thereby reducing the size of
the distillation apparatus and the cost of manufacture and
operation of the distillation apparatus. Furthermore, there can be
simplified equipment for controlling the operation of the
distillation apparatus and maintaining the distillation apparatus.
Since the product can be collected in the form of liquid, flow rate
control of the product can be significantly simplified, thereby
reducing the cost of manufacture and operation of the distillation
apparatus.
[0172] Since the product is collected at the side of the column
body, the product is not exposed to high temperature induced by the
evaporator 82 disposed at the bottom of the column body. Also, the
product does not require additional heating by a heater. Thus,
formation of modified component B' within the product can be
prevented, thereby enhancing product quality.
[0173] The product collected at the side of the column body is
immediately cooled by means of the cooler 192, thereby preventing
decomposition of component B which would otherwise result from heat
held by the product itself. Thus, formation of modified component
B' within the product can be more reliably prevented.
[0174] Preferably, the coupling-type distillation column 10 has a
total of about 30-100 theoretical stages, and about 5-30
theoretical stages are allocated to each of the fourth section 14
and the sixth section 16.
[0175] In the present embodiment, each of the enriching sections
AR1, AR3, and AR5 and the exhaust sections AR2, AR4, and AR6 is
formed of a packing including a single node. However, depending on
relative volatility among components to be obtained through
distillation, each of the enriching sections AR1, AR3, and AR5 and
the exhaust sections AR2, AR4, and AR6 may be formed of a packing
including a plurality of nodes corresponding to characteristics of
a packing to be used, in order to attain the number of theoretical
stages required for distillation. Also, a distributor may be
disposed between the nodes. Furthermore, the feed nozzle 41 and the
side cut nozzle 42 are not necessarily disposed at the same
level.
[0176] Next will be described a third embodiment of the present
invention adapted to separate, through distillation, components A
and B from a material liquid M containing two components A and B.
Structural features similar to those of the first embodiment are
denoted by common reference numerals, and repeated description
thereof is omitted.
[0177] FIG. 14 conceptually shows a distillation apparatus
according to a third embodiment of the present invention. FIG. 15
conceptually shows a coupling-type distillation column used in the
distillation apparatus of the third embodiment.
[0178] In this case, components A and B are separated, through
distillation, from the material liquid M containing two components
A and B. Component X serving as an additive component and fed
through a line L70 is added to the material liquid M fed through
the line L51 to thereby form an adjusted material liquid MX
containing components A, B, and X. The adjusted material liquid MX
is fed to the feed nozzle 41 through the line L50. Component X is
lower in boiling point than component A, which in turn is lower in
boiling point than component B. Component X serves as an additive
component; component A serves as a low-boiling-point component; and
component B serves as a high-boiling-point component. Components A
and B are formed from respective high-melting-point materials.
Component X is formed from such a material that can be readily
separated from component A and is unlikely to be modified during
distillation.
[0179] The operation of the distillation apparatus will next be
described.
[0180] In the exhaust section AR2, the adjusted material liquid MX
fed through the feed nozzle 41 undergoes vapor-liquid separation
such that vapor rich in components X and A is generated at an upper
portion thereof, while fluid composed of vapor and liquid rich in
components A and B is increasingly generated along the descending
direction. The fluid is fed to the third distillation section 27
from the lower end of the first distillation section 25.
[0181] The fluid is heated in the third distillation section 27 to
thereby become vapor rich in components A and B. During ascending
in the exhaust section AR2, the vapor rich in components A and B
contacts the adjusted material liquid MX. As a result, component X
contained in the adjusted material liquid MX is prevented from
descending and is thus collected. Thus is prevented mixing of
component X into the fluid fed to the third distillation section
27.
[0182] The vapor rich in components X and A ascends in the
enriching section AR1 and is then fed to the second distillation
section 26 from the upper end of the first distillation section 25.
The vapor rich in components X and A is cooled in the second
distillation section 26 to thereby be condensed into liquid rich in
components X and A. A portion of the liquid rich in components X
and A is refluxed to the enriching section AR1 and brought into
contact with the vapor rich in components X and A which is
ascending in the enriching section AR1.
[0183] In this manner, the vapor rich in components X and A can be
fed to the second distillation section 26 from the upper end of the
first distillation section 25.
[0184] In the exhaust section AR6, liquid rich in components A and
B descends, during which vapor rich in component A is generated at
an upper portion thereof, and liquid rich in component B is
increasingly generated along the descending direction. The liquid
rich in component B is discharged as a column-bottom liquid to the
line L52 from the column-bottom liquid outlet 45.
[0185] A portion of the column-bottom liquid is sent to the
evaporator 82 through the line L53. In the evaporator 82, the
liquid is evaporated through application of heat to thereby become
vapor rich in component B. The vapor rich in component B is fed to
the vapor inlet 46 through the line L54 to thereby be fed to the
ninth section 19. During ascending in the ninth section 19 and the
exhaust section AR6, the vapor rich in component B contacts liquid
rich in components A and B; as a result, vapor rich in component A
is generated from the liquid rich in components A and B. The
remaining column-bottom liquid is fed to an unillustrated
column-bottom liquid accommodation section through the line
L55.
[0186] Then, a portion of the vapor rich in component A ascends in
the enriching section AR5, during which the portion of the vapor
rich in component A contacts the liquid rich in component A from
the second distillation section 26 at the upper end of the third
distillation section 27 to thereby become liquid rich in component
A. The liquid rich in component A obtained at the upper end of the
third distillation section 27 is discharged as a side cut liquid
from the side cut nozzle 42 to the line L56. The discharged side
cut liquid is fed to an unillustrated side cut liquid accommodation
section. As a result, component A can be collected as a product
from the side of the coupling-type distillation column 10. The line
L56 serves as the first discharge system.
[0187] In the exhaust section AR4 of the second distillation
section 26, liquid rich in components X and A descends, during
which vapor rich in component X is generated at an upper portion
thereof, and liquid rich in component A is increasingly generated
along the descending direction.
[0188] The vapor rich in component X ascends in the enriching
section AR3 and is then discharged from the vapor outlet 43 to the
line L57. The discharged vapor rich in component X is sent to the
condenser 81, where the vapor is condensed into liquid rich in
component X, which is discharged as distillate to the line L58. In
order to enhance the efficiency of distillation for component X, a
portion of the distillate is sent to the reflux liquid inlet 44
through the line L59 and refluxed into the first section 11 through
the reflux liquid inlet 44. The refluxed distillate is brought into
contact with vapor rich in components X and A ascending in the
enriching section AR3. The remaining distillate is added to the
material liquid M through the line L70.
[0189] As described above, vapor rich in components X and A is
separated into vapor rich in component X and liquid rich in
component A by means of the second distillation section 26. At the
top of the column body the vapor rich in component X is discharged
through the vapor outlet 43 and condensed into liquid rich in
component X by means of the condenser 81. The liquid rich in
component X is discharged as distillate from the condenser 81. At
the side of the column body the liquid rich in component A is
discharged as a side cut liquid through the side cut nozzle 42.
Liquid rich in components A and B is separated into liquid rich in
component A and liquid rich in component B by means of the third
distillation section 27. The liquid rich in component A is
discharged as a side cut liquid through the side cut nozzle 42. At
the bottom of the column body the liquid rich in component B is
discharged as a column-bottom liquid through the column-bottom
liquid outlet 45.
[0190] As described above, the adjusted material liquid MX can be
separated into components X, A, and B without use of a plurality of
distillation columns. Since there is no need to repeat heating and
cooling in a plurality of distillation columns, the number of
instruments, such as condensers, evaporators, and pumps, can be
reduced. Accordingly, an area to be occupied by the distillation
apparatus can be reduced, and the amount of consumption of
utilities and consumed energy can be reduced as well, thereby
reducing the cost of the distillation apparatus.
[0191] Since the melting points of components A and B are higher
than ambient temperature, the lines L52, L53, L55, and L56 assume a
double-pipe structure in order to prevent solidification of the
side cut liquid within the line L56 and solidification of the
column-bottom liquid within the lines L52, L53, and L55. The lines
L52, L53, and L55 constitute the second discharge system. The
double-pipe structure that the line L56 assumes serves as the first
solidification prevention means, and the double-pipe structure that
the lines L52, L53, and L55 assume serves as the second
solidification prevention means. The double-pipe structure is
composed of an inner pipe and an outer pipe disposed
concentrically. Steam serving as a heating medium is caused to flow
through the space between the inner and outer pipes to thereby
prevent solidification of the column-bottom liquid or the side cut
liquid flowing through the inner pipe. The present embodiment
employs the double-pipe structure as the first and second
solidification prevention means. However, steam tracing may be
employed in place of the double-pipe structure. Steam tracing is
composed of a primary pipe and a secondary pipe disposed in
parallel. Steam serving as a heating medium is caused to flow
through the secondary pipe to thereby prevent solidification of the
column-bottom liquid or the side cut liquid flowing through the
primary pipe.
[0192] Through addition of component X to the material liquid M,
vapor rich in component X is discharged from the top of the column
body. Thus, there is no need to collect component A as a product at
the top of the column body. Since the vapor rich in component X is
condensed by means of the condenser 81, there is no need to
condense vapor rich in component A by means of a condenser.
[0193] When the vapor rich in component X discharged from the top
of the column body is condensed by means of the condenser 81,
ordinary cooling water is used as a cooling medium for cooling the
vapor. Since the melting point of component X is lower than the
temperature of cooling water (for example, the melting point of
component X is lower than a cooling water temperature of 30.degree.
C. to 35.degree. C.), the vapor rich in component X can be
sufficiently condensed without involvement of solidification of the
vapor within the condenser 81.
[0194] Accordingly, there is no need to use hot water, cooling oil,
or steam as the cooling medium. As a result, there is no need to
connect a cooling system to the condenser 81.
[0195] In order to reduce energy consumed for heating a
column-bottom liquid in the evaporator 82, preferably the
evaporator 82 is lowered in temperature. However, when the
evaporator 82 is lowered in temperature, evaporation of the
column-bottom liquid becomes difficult accordingly. In order to
cope with this problem, an unillustrated vacuum generator serving
as the negative-pressure generation means is connected to the
condenser 81, so as to establish a negative pressure within the
coupling-type distillation column 10. As a result, the
column-bottom liquid can be readily evaporated. Also, vent gas
generated within the coupling-type distillation column 10 can be
drawn out and released into the atmosphere.
[0196] In this case, an unillustrated gas cooler is disposed
between the condenser 81 and the unillustrated vacuum generator in
order to cool vent gas withdrawn by means of the vacuum generator.
Thus, when vent gas mixed with vapor rich in component X is sent
from the condenser 81 to the gas cooler and cooled in the gas
cooler, the vapor becomes liquid rich in component X to thereby be
separated from the vent gas. Thus, there is no need to dispose a
vent gas treatment apparatus between the condenser 81 and the
vacuum generator. Notably, the gas cooler can use ordinary cooling
water as a cooling medium.
[0197] As mentioned above, vapor rich n component X is discharged
from the top of the column body, and component X is formed from a
low-melting-point material. Thus, there is no need to employ
various auxiliary apparatus such as a hot water tank, a cooler, an
oil tank, a condenser, a vent scrubber, and a heat exchanger.
Therefore, the distillation apparatus allows a reduction in area
occupied thereby and can be manufactured and operated at low
cost.
[0198] Also, a portion of the distillate is refluxed to the first
section 11 through the reflux liquid inlet 44, and the remaining
distillate is added to the material liquid M through the line L70.
Thus, component X can be repeatedly used through addition to the
material liquid M, thereby reducing the cost of operation of the
distillation apparatus.
[0199] Next, a fourth embodiment of the present invention will be
described. Structural features similar to those of the third
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0200] FIG. 16 conceptually shows a distillation apparatus
according to the fourth embodiment of the present invention.
[0201] In this case, vapor rich in component X is discharged from
the vapor outlet 43 to the line L57. The discharged vapor rich in
component X is sent to the condenser 81, where the vapor is
condensed into liquid rich in component X, which is discharged as
distillate to the line L58. In order to enhance the efficiency of
distillation for component X, most of the distillate is sent to the
reflux liquid inlet 44 through the line L59 and refluxed into the
first section 11 through the reflux liquid inlet 44. The refluxed
distillate is brought into contact with vapor rich in components X
and A ascending in the enriching section AR3. The remaining
distillate is discharged through a line L81 for makeup
replacement.
[0202] Through a line L82, component X is added to the material
liquid M in an amount corresponding to the amount of distillate
which has been discharged for makeup replacement.
[0203] Next, a fifth embodiment of the present invention will be
described. Structural features similar to those of the third
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0204] FIG. 17 conceptually shows a distillation apparatus
according to the fifth embodiment of the present invention.
[0205] In this case, vapor rich in component X is discharged from
the vapor outlet 43 to the line L57. The discharged vapor rich in
component X is sent to the condenser 81, where the vapor is
condensed into liquid rich in component, which is discharged as
distillate to a line L83. In order to enhance the efficiency of
distillation for component X, all of the distillate is sent to the
reflux liquid inlet 44 through the line L83 and refluxed into the
first section 11 through the reflux liquid inlet 44. The refluxed
distillate is brought into contact with vapor rich in components X
and A ascending in the enriching section AR3.
[0206] In order to start operation of the distillation apparatus,
component X is added in a predetermined amount to the material
liquid M through a line L84.
[0207] According to the third through fifth embodiments, an
unillustrated gas cooler is disposed between the condenser 31 and
the vacuum generator. However, a vent-scrubber-type vent gas
treatment apparatus may be disposed in place of the gas cooler. In
this case, since solution to be used is not required to have the
capability of sufficiently adsorbing vapor rich in component A,
which is formed from a high-melting-point material, the cost of
operation of the distillation apparatus can be reduced.
[0208] According to the third through fifth embodiments, vapor rich
in component X is discharged from the vapor outlet 43 to the line
L57, and the discharged vapor rich in component X is sent to the
condenser 81. However, a condenser may be disposed within the first
section of the column body to thereby connect the top of the column
body and the condenser.
[0209] Meanwhile, in obtainment of component B as a product from
the material liquid M containing components A and B, component B,
when heated by means of an evaporator, is decomposed into modified
component B', which is higher in boiling point than component B.
When component B collected as a product contains modified component
B', which is an impurity, the hue and odor of the product are
affected, since modified component B' has a large molecular mass of
carbon. A sixth embodiment of the present invention, which will be
described below, is adapted to prevent entry of impurities into a
product. Structural features similar to those of the third
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0210] FIG. 18 conceptually shows a distillation apparatus
according to the sixth embodiment of the present invention. FIG. 19
conceptually shows a coupling-type distillation column used in the
distillation apparatus of the sixth embodiment.
[0211] In this case, components A and B are separated, through
distillation, from the material liquid M containing two components
A and B. Component X serving as an additive component and fed
through a line L66 is added to the material liquid M fed through
the line L51 to thereby form an adjusted material liquid MX
containing components A, B, and X. The adjusted material liquid MX
is fed to the feed nozzle 41 through the line L50. Also, component
X serving as an initial charge or makeup is added to the material
liquid M through the line L82. Component A is lower in boiling
point than component B, which in turn is lower in boiling point
than component X. Component A serves as a low-boiling-point
component; component B serves as a high-boiling-point component;
and component X serves as an additive component. Component X is
formed from such a material that can be readily separated from
component B and is unlikely to be modified during distillation.
[0212] The operation of the distillation apparatus will next be
described.
[0213] In the exhaust section AR2, the adjusted material liquid MX
fed through the feed nozzle 41 undergoes vapor-liquid separation
such that vapor rich in components A and B is generated at an upper
portion thereof, while fluid composed of vapor and liquid rich in
components B and X is increasingly generated along the descending
direction. The fluid is fed to the third distillation section 27
from the lower end of the first distillation section 25.
[0214] The fluid is heated in the third distillation section 27 to
thereby become vapor rich in components B and X. During ascending
in the exhaust section AR2, the vapor rich in components B and X
contacts the adjusted material liquid MX. As a result, component A
contained in the adjusted material liquid MX is prevented from
descending and is thus collected. Thus is prevented mixing of
component A into the fluid fed to the third distillation section
27.
[0215] The vapor rich in components A and B ascends in the
enriching section AR1 and is then fed to the second distillation
section 26 from the upper end of the first distillation section 25.
The vapor rich in components A and B is cooled in the second
distillation section 26 to thereby be condensed into liquid rich in
components A and B. A portion of the liquid rich in components A
and B is refluxed to the enriching section AR1 and brought into
contact with the vapor rich in components A and B which is
ascending in the enriching section AR1.
[0216] In this manner, the vapor rich in components A and B can be
fed to the second distillation section 26 from the upper end of the
first distillation section 25.
[0217] In the exhaust section AR6, liquid rich in components B and
X descends, during which vapor rich in component B is generated at
an upper portion thereof, and liquid rich in component X is
increasingly generated along the descending direction. The liquid
rich in component X is discharged as a column-bottom liquid to the
line L52 from the column-bottom liquid outlet 45.
[0218] A portion of the column-bottom liquid is sent to the
evaporator 82 through the line L53. In the evaporator 32, the
liquid is evaporated through application of heat to thereby become
vapor rich in component X. The vapor rich in component X is fed to
the vapor inlet 46 through the line L54 to thereby be fed to the
ninth section 19. During ascending in the ninth section 19 and the
exhaust section AR6, the vapor rich in component X contacts liquid
rich in components B and X; as a result, vapor rich in component B
is generated from the liquid rich in components B and X. The
remaining column-bottom liquid is added as an additive component to
the material liquid M through the line L66.
[0219] Then, a portion of the vapor rich in component B ascends in
the enriching section AR5, during which the portion of the vapor
rich in component B contacts the liquid rich in component B from
the second distillation section 26 at the upper end of the third
distillation section 27 to thereby become liquid rich in component
B. The liquid rich in component B obtained at the upper end of the
third distillation section 27 is discharged as a side cut liquid
from the side cut nozzle 42 to the line L56. The discharged side
cut liquid is fed to an unillustrated side cut liquid accommodation
section via a cooler 83 serving as cooling means, a line L64, a
flow regulating valve 85, and a line L65. In this manner, component
B can be collected as a product from the side of the coupling-type
distillation column 10. A flow sensor 84 is disposed on the line
L64. On the basis of a flow rate detected by means of the flow
sensor 84, the flow regulating valve 85 is regulated. The lines
L56, L64, and L65, the cooler 83, the flow sensor 84, and the flow
regulating valve 85 constitute the first discharge system. The
lines L52, L53, and L76 constitute the second discharge system.
[0220] In the exhaust section AR4 of the second distillation
section 26, liquid rich in components A and B descends, during
which vapor rich in component A is generated at an upper portion
thereof, and liquid rich in component B is increasingly generated
along the descending direction.
[0221] The vapor rich in component A ascends in the enriching
section AR3 and is then discharged from the vapor outlet 43 to the
line L57. The discharged vapor rich in component A is sent to the
condenser 81, where the vapor is condensed into liquid rich in
component A, which is discharged as distillate to the line L58. In
order to enhance the efficiency of distillation for component A, a
portion of the distillate is sent to the reflux liquid inlet 44
through the line L59 and refluxed into the first section 11 through
the reflux liquid inlet 44. The refluxed distillate is brought into
contact with vapor rich in components A and B ascending in the
enriching section AR3. The remaining distillate is fed to an
unillustrated distillate accommodation section through the line
L60.
[0222] As described above, vapor rich in components A and B is
separated into vapor rich in component A and liquid rich in
component B by means of the second distillation section 26. The
vapor rich in component A is discharged through the vapor outlet 43
and condensed into liquid rich in component A by means of the
condenser 81. The liquid rich in component A is discharged as
distillate from the condenser 81. The liquid rich in component B is
discharged as a side cut liquid through the side cut nozzle 42.
Liquid rich in components B and X is separated into liquid rich in
component B and liquid rich in component X by means of the third
distillation section 27. The liquid rich in component B is
discharged as a side cut liquid through the side cut nozzle 42. The
liquid rich in component X is discharged as a column-bottom liquid
through the column-bottom liquid outlet 45.
[0223] As described above, the adjusted material liquid MX can be
separated into components A, B, and X without use of a plurality of
distillation columns. Since there is no need to repeat heating and
cooling in a plurality of distillation columns, the number of
instruments, such as condensers, evaporators, and pumps, can be
reduced. Accordingly, an area to be occupied by the distillation
apparatus can be reduced, and the amount of consumption of
utilities and consumed energy can be reduced as well, thereby
reducing the cost of the distillation apparatus.
[0224] According to the present embodiment, modified component B',
which is formed through decomposition of component B and is higher
in boiling point than component B, gathers in the vicinity of the
bottom of the column body and is then discharged to the line L52
through the column-bottom liquid outlet 45. Subsequently, modified
component B, together with a portion of component X, is discharged
to an external destination through the line L76. Thus is prevented
accumulation of modified component B' at the bottom of the column
body.
[0225] Thus, modified component B' and component B do not contact
each other while these components are in the form of liquid.
Therefore, the product to be collected does not contain modified
component B', which is an impurity. As a result, the hue and odor
of the product are not affected.
[0226] Also, impurities can be removed from the product without use
of auxiliary apparatus such as a valve, a product condenser, a
receiver, and a heater, thereby reducing the size of the
distillation apparatus and the cost of manufacture and operation of
the distillation apparatus. Furthermore, there can be simplified
equipment for controlling the operation of the distillation
apparatus and maintaining the distillation apparatus. Since the
product can be collected in the form of liquid, flow rate control
of the product can be significantly simplified, thereby reducing
the cost of manufacture and operation of the distillation
apparatus.
[0227] Since the product is collected at the side of the column
body, the product is not exposed to high temperature induced by the
evaporator 82 disposed at the bottom of the column body. Also, the
product does not require additional heating by a heater. Thus,
formation of modified component B', which is an impurity, can be
prevented, thereby enhancing product quality.
[0228] The product collected at the side of the column body is
immediately cooled by means of the cooler 83, thereby preventing
decomposition of component B which would otherwise result from heat
held by the product itself. Thus, formation of modified component
B' within the product can be prevented.
[0229] Also, a portion of the column-bottom liquid is fed to the
ninth section 19, and the remaining column-bottom liquid is added
to the material liquid M. Thus, component X can be repeatedly used
through addition to the material liquid M, thereby reducing the
cost of operation of the distillation apparatus.
[0230] In order to carry out distillation in a low-temperature
region for prevention of impairment in product quality and to
reduce energy consumed for heating a portion of a column-bottom
liquid in the evaporator 82, an unillustrated vacuum generator is
disposed for use with the condenser 81. The vacuum generator
generates a negative pressure within the coupling-type distillation
column 10. As a result, the column-bottom liquid can be readily
evaporated at low temperature. Also, vent gas generated within the
coupling-type distillation column 10 can be drawn out and released
into the atmosphere.
[0231] Nest, a seventh embodiment of the present invention will be
described. Structural features similar to those of the sixth
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0232] FIG. 20 conceptually shows a distillation apparatus
according to the seventh embodiment of the present invention.
[0233] In this case, liquid rich in component A is discharged as a
column-bottom liquid from the column-bottom liquid outlet 45 to the
line L52. In order to enhance the efficiency of distillation for
component X, most of the discharged column-bottom liquid rich in
component X is sent to the evaporator 82 through the line L53 and
evaporated. The thus-generated vapor is sent to the vapor inlet 46
through the line L54 and fed to the ninth section 19 through the
vapor inlet 46. The remaining column-bottom liquid, together with
modified component B', is discharged through a line L85 for makeup
replacement.
[0234] Through the line L82, component X is added to the material
liquid M in an amount corresponding to the amount of the
column-bottom liquid which has been discharged for makeup
replacement.
[0235] Next, an eighth embodiment of the present invention will be
described. Structural features similar to those of the sixth
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0236] FIG. 21 conceptually shows a distillation apparatus
according to the eighth embodiment of the present invention.
[0237] In this case, liquid rich in component X is discharged as a
column-bottom liquid to the line L52. In order to enhance the
efficiency of distillation for component X, all of the discharged
column-bottom liquid is sent to the evaporator 82 through the line
L52 and evaporated into vapor rich in component X. The
thus-generated vapor rich in component X is sent to the vapor inlet
46 through a line L86 and fed to the ninth section 19 through the
vapor inlet 46.
[0238] In order to start operation of the distillation apparatus,
component X is added in a predetermined amount to the material
liquid M through the line L84.
[0239] Next, a ninth embodiment of the present invention will be
described. Structural features similar to those of the sixth
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0240] FIG. 22 conceptually shows a main portion of a distillation
apparatus according to the ninth embodiment of the present
invention.
[0241] In this case, liquid rich in component B is discharged as a
side cut liquid to a line L91 through the side cut nozzle 42. The
side cut liquid is sent under pressure to the cooler 83 serving as
cooling means through a line L92 by means of a pump 86.
[0242] Next, a tenth embodiment of the present invention will be
described. Structural features similar to those of the sixth
embodiment are denoted by common reference numerals, and repeated
description thereof is omitted.
[0243] FIG. 23 conceptually shows a main portion of a distillation
apparatus according to the tenth embodiment of the present
invention.
[0244] In this case, liquid rich in component B is discharged as a
side cut liquid to a line L93 through the side cut nozzle 42. The
side cut liquid is fed to a receiver 87 serving as cooling means
and cooled therein. The receiver 87 includes a cooling coil 93,
through which cooling water flows.
[0245] The side cut liquid cooled in the receiver 87 is fed to a
pump 88 through a line L94. A portion of the side cut liquid
discharged from the pump 88 is sent under pressure to the flow
regulating valve 85 through lines L95 and L96. The remaining side
cut liquid discharged from the pump 88 is sent under pressure to a
side cut feed inlet 90 through the line L95, a line L98, a flow
regulating valve 89, and a line L99 and fed to the second chamber
15B through the side cut feed inlet 90.
[0246] According to the sixth through tenth embodiments, vapor rich
in component A is discharged to the line L57 through the vapor
outlet 43 and is then sent to the condenser 81. However, through
disposition of a condenser in the first section of the column body,
the condenser and the top of the column body can be directly
connected.
[0247] The distillation apparatus of the above-described
embodiments can separate, through distillation, organic compounds,
such as hydrocarbons, alcohols, ketones, esters, fatty acids,
phenols, nitrogen compounds, and perfumes. Hydrocarbons include
benzene, toluene, xylene, biphenyl, and naphthalene; alcohols
include methanol, ethanol, butanol, heptanol, and octanol; ketones
include acetone, methyl ethyl ketone, and methyl isobutyl ketone;
esters include ethyl acetate, butyl acetate, methyl acetate, and
butyl acrylate; fatty acids include acetic acid, and butyric acid;
phenols include phenol, cresol, and xylenol; nitrogen compounds
include dimethylamine, triethylamine, aniline, pyridine, picoline,
and quinoline; and perfumes include methyl anthranilate, methyl
benzoate, isoeugenol, ethyl caproate, eugenol, and geraniol.
[0248] The distillation apparatus of the above-described
embodiments are particularly suited to separate perfumes, fats and
oils, and fatty acids having a high boiling point and C8-C22 in the
number of carbons, under reduced pressure on the job-shop-type
production basis.
[0249] The present invention is not limited to the above-described
embodiments. Numerous modifications and variations of the present
invention are possible in light of the spirit of the present
invention, and they are not excluded from the scope of the present
invention.
* * * * *