DISTILLATION DEVICE

Abstract

The present application relates to a distillation device. By using the distillation device of the present application, energy loss occurring during a purification process of a mixture including an isomer, for example, a raw material including n-butyl aldehyde and iso-butyl aldehyde, can be minimized, and a high-purity product can be separated, thus increasing economic efficiency of a process.

Claims

1. A distillation device, comprising a first distillation unit that comprises a first condenser, a first reboiler and a first distillation column; a second distillation unit that comprises a second condenser, a second reboiler, and a second distillation column; and a heat exchanger, wherein a raw material comprising a compound represented by Formula 1 below and an isomer of the compound is introduced into a first supply port of the first distillation column and/or a second supply port of the second distillation column, the raw material introduced into the first supply port of the first distillation column is separately discharged into each of a first column top stream discharged from an upper section of the first distillation column; and first, second and third column bottom streams separately discharged from a lower section of the first distillation column, the first column top stream is introduced into the first condenser, and a portion or all of the first column top stream via the first condenser is refluxed in the upper section of the first distillation column, the first column bottom stream is introduced into the first reboiler, and the first column bottom stream via the first reboiler is refluxed in the lower section of the first distillation column, the stream introduced into the second supply port of the second distillation column is separately discharged to each of a second column top stream discharged from an upper section of the second distillation column; and fourth and fifth column bottom streams discharged from a lower section of the second distillation column, the fourth column bottom stream is introduced into the second reboiler, and the fourth column bottom stream via the second reboiler is refluxed in the lower section of the second distillation column, the third column bottom stream and the second column top stream are introduced into the heat exchanger and exchange heat therebetween, the third column bottom stream via the heat exchanger is refluxed in the lower section of the first distillation column, the second column top stream via the heat exchanger is introduced into the second condenser, and a portion or all of the second column top stream via the second condenser is refluxed in the upper section of the second distillation column, and Equations 1 and 2 are satisfied: ##STR00004## wherein R is a C.sub.1 to C.sub.12 alkyl group;
T.sub.t-2−T.sub.b-3≧8° C.  [Equation 1]
P.sub.2/P.sub.1≧20  [Equation 2] wherein T.sub.t-2 indicates a temperature of the second column top stream, and T.sub.b-3 indicates a temperature of the third column bottom stream, and P.sub.1 indicates a pressure of the upper section of the first distillation column (kg/cm.sup.2g), and P.sub.2 indicates a pressure of the upper section of the second distillation column (kg/cm.sup.2g).

2. The distillation device according to claim 1, wherein the raw material is introduced into each of the first supply port of the first distillation column and the second supply port of the second distillation column.

3. The distillation device according to claim 2, wherein the compound represented by Formula 1 is n-butyl aldehyde, and the isomer of the compound is iso-butyl aldehyde, wherein a content of the iso-butyl aldehyde in each of the first column top stream and the second column top stream is 90% or more, and a content of the n-butyl aldehyde in each of the second column bottom stream and the fifth column bottom stream is 90% or more.

4. The distillation device according to claim 2, wherein the distillation device satisfies Equation 3 below:
0.3≦F.sub.1/F.sub.2≦3.0,  [Equation 3] wherein F.sub.1 indicates a discharge rate of the raw material (ton/hr) introduced into the first supply port of the first distillation column, and F.sub.2 indicates a discharge rate of the raw material (ton/hr) introduced into the second supply port of the second distillation column.

5. The distillation device according to claim 1, wherein a pressure of the upper section of the first distillation column is 0.01 to 0.1 kg/cm.sup.2g.

6. The distillation device according to claim 1, wherein a pressure of the upper section of the second distillation column is 2.3 to 2.7 kg/cm.sup.2g.

7. The distillation device according to claim 1, wherein a temperature of the upper section of the first distillation column is 60 to 70° C.

8. The distillation device according to claim 1, wherein a temperature of the lower section of the first distillation column is 90 to 100° C.

9. The distillation device according to claim 1, wherein a temperature of the upper section of the second distillation column is 100 to 110° C.

10. The distillation device according to claim 1, wherein a temperature of the lower section of the second distillation column is 120 to 140° C.

11. The distillation device according to claim 1, wherein the raw material is supplied to the first supply port of the first distillation column, and the second column bottom stream of the first distillation column is supplied to the second supply port of the second distillation column.

12. The distillation device according to claim 11, wherein the compound represented by Formula 1 is n-butyl aldehyde, and the isomer of the compound is iso-butyl aldehyde, wherein a content of the iso-butyl aldehyde in the first column top stream is 90% or more, and a content of the n-butyl aldehyde in the second column top stream is 90% or more.

13. The distillation device according to claim 11, wherein a portion of the fifth column bottom stream discharged from the lower section of the second distillation column is introduced into the lower section of the first distillation column.

14. The distillation device according to claim 11, wherein a pressure of the upper section of the first distillation column is 0.01 to 0.1 kg/cm.sup.2g.

15. The distillation device according to claim 11, wherein a pressure of the upper section of the second distillation column is 1.0 to 2.0 kg/cm.sup.2g.

16. The distillation device according to claim 11, wherein a temperature of the upper section of the first distillation column is 60 to 70° C.

17. The distillation device according to claim 11, wherein a temperature of the lower section of the first distillation column is 90 to 100° C.

18. The distillation device according to claim 11, wherein a temperature of the upper section of the second distillation column is 100 to 110° C.

19. The distillation device according to claim 11, wherein a temperature of the lower section of the second distillation column is 120 to 140° C.

20. A method of preparing a compound represented by Formula 1, the method comprising: introducing a raw material comprising the compound represented by Formula 1 below and an isomer of the compound into each of a first supply port of a first distillation column and a second supply port of a second distillation column; discharging the raw material introduced into the first supply port to each of a first column top stream discharged from an upper section of the first distillation column; and first, second and third column bottom streams discharged from a lower section of the first distillation column; discharging the raw material introduced into the second supply port to each of a second column top stream discharged from an upper section of the second distillation column; and fourth and fifth column bottom streams discharged from a lower section of the second distillation column; heat-exchanging the second column top stream with the third column bottom stream; and separating the compound represented by Formula 1 from the lower section of the first distillation column, and the isomer of the compound represented by Formula 1 from the upper section of the first distillation column and the upper section of the second distillation column, wherein Equations 1 and 2 below are satisfied: ##STR00005## wherein R is a C.sub.1 to C.sub.12 alkyl group;
T.sub.t-2−T.sub.b-3≧8° C.  [Equation 1]
P.sub.2/P.sub.1≧20  [Equation 2] wherein T.sub.t-2 indicates a temperature of the second column top stream, and T.sub.b-3 indicates a temperature of the third column bottom stream, and P.sub.1 indicates a pressure of the upper section of the first distillation column (kg/cm.sup.2g), and P.sub.2 indicates a pressure of the upper section of the second distillation column (kg/cm.sup.2g).

21. A method of preparing a compound represented by Formula 1, the method comprising: introducing a raw material comprising the compound represented by Formula 1 below and an isomer of the compound into a first supply port of a first distillation column; discharging the introduced raw material to each of a first column top stream discharged from an upper section of the first distillation column; and first, second and third column bottom streams discharged from a lower section of the first distillation column; introducing the first column bottom stream into a second supply port of a second distillation column, discharging the stream introduced into the second supply port to each of a second column top stream discharged from an upper section of the second distillation column; and fourth and fifth column bottom streams discharged from a lower section of the second distillation column; heat-exchanging the second column top stream with the third column bottom stream; and separating the compound represented by Formula 1 from the upper section of the second distillation column, and the isomer of the compound represented by Formula 1 from the upper section of the first distillation column, wherein Equations 1 and 2 below are satisfied: ##STR00006## wherein R is a C.sub.1 to C.sub.12 alkyl group;
T.sub.t-2−T.sub.b-3≧8° C.  [Equation 1]
P.sub.2/P.sub.1≧20  [Equation 2] wherein T.sub.t-2 indicates a temperature of the second column top stream, and T.sub.b-3 indicates a temperature of the third column bottom stream, and P.sub.1 indicates a pressure of the upper section of the first distillation column (kg/cm.sup.2g), and P.sub.2 indicates a pressure of the upper section of the second distillation column (kg/cm.sup.2g).

Description

DESCRIPTION OF DRAWINGS

[0075] FIG. 1 exemplarily illustrates a distillation device according to an embodiment of the present application.

[0076] FIG. 2 exemplarily illustrates a distillation device according to another embodiment of the present application.

[0077] FIG. 3 exemplarily illustrates a general separation device used in a comparative example.

BEST MODE

[0078] Now, the present invention will be described in more detail with reference to examples according to the present invention and comparative examples not according to the present invention. These examples are provided for illustrative purposes only and should not be construed as limiting the scope and spirit of the present invention.

Example 1

[0079] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device illustrated in FIG. 1. In particular, a raw material including n-butyl aldehyde and iso-butyl aldehyde was introduced into each of a first distillation column with a theoretical plate number of 100 and a second distillation column with a theoretical plate number of 100. In this case, a ratio of the discharge rate of the raw material introduced into the first distillation column to the discharge rate of the raw material introduced into the second distillation column was controlled to 2:3.

[0080] A portion of a first column top stream discharged from an upper section of the first distillation column was refluxed in the upper section of the first distillation column via a first condenser. A portion of the remainder of the first column top stream was separated as a product including iso-butyl aldehyde and stored. A portion of a first column bottom stream discharged from a lower section of the first distillation column was refluxed in the lower section of the first distillation column via a first reboiler. A second column bottom stream discharged from the lower section of the first distillation column was separated as a product including n-butyl aldehyde and stored. A third column bottom stream discharged from the lower section of the first distillation column was introduced into a heat exchanger and heat-exchanged with a second column top stream of the second distillation column introduced into the heat exchanger, followed by being refluxed in the lower section of the first distillation column via the heat exchanger. In this case, operation pressure of the upper section of the first distillation column was adjusted to 0.02 Kg/cm.sup.2g and operation temperature thereof was adjusted to 65° C. Operation temperature of the lower section of the first distillation column was adjusted to 95° C.

[0081] Meanwhile, the second column top stream discharged from an upper section of the second distillation column was introduced into the heat exchanger and heat-exchanged with the third column bottom stream. Subsequently, a portion of the second column top stream having passed through the heat exchanger and a second condenser was refluxed in the upper section of the second distillation column, and a portion of the remainder of the second column top stream was separated as a product including iso-butyl aldehyde. A fourth column bottom stream discharged from a lower section of the second distillation column was refluxed in the lower section of the second distillation column via a second reboiler, and a fifth column bottom stream discharged from the lower section of the second distillation column was separated as a product including n-butyl aldehyde. In this case, operation pressure of the upper section of the second distillation column was adjusted to 2.5 Kg/cm.sup.2g, and operation temperature thereof was adjusted to 105° C. Operation temperature of the lower section of the second distillation column was adjusted to 129° C.

[0082] N-butyl aldehyde and iso-butyl aldehyde were separated by means of the distillation device of Example 1. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 1 below.

Example 2

[0083] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 1 below.

[0084] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 2. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 1 below.

Example 3

[0085] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 1 below.

[0086] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 3. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 1 below.

Example 4

[0087] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 2, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 1 below.

[0088] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 4. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 1 below.

Example 5

[0089] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 2, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 1 below.

[0090] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 5. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 1 below.

Comparative Example 1

[0091] As illustrated in FIG. 3, n-butyl aldehyde and iso-butyl aldehyde were separated by means of one distillation column. A portion of a stream with a low boiling point discharged from an upper section of the distillation column was refluxed in the distillation column via a condenser, and a portion of the remainder of the stream was produced as a product including iso-butyl aldehyde. A portion of a stream discharged from a lower section of the distillation column was refluxed in the distillation column via a reboiler, and a portion of the remainder of the stream was separated as a product including n-butyl aldehyde. In this case, operation pressure of the upper section of the distillation column was adjusted to 0.32 Kg/cm.sup.2g, and the operation temperature thereof was adjusted to 73° C. Operation temperature of the lower section of the distillation column was adjusted to 100° C.

[0092] N-butyl aldehyde and iso-butyl aldehyde were separated by means of the distillation device of Comparative Example 1. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 2 below.

Comparative Example 2

[0093] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 2 below.

[0094] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 2. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 2 below.

Comparative Example 3

[0095] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 2 below.

[0096] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 3. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 2 below.

Comparative Example 4

[0097] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 2 below.

[0098] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 4. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 2 below.

Comparative Example 5

[0099] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0100] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 5. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 3 below.

Comparative Example 6

[0101] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0102] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 6. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 3 below.

Comparative Example 7

[0103] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0104] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 7. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 3 below.

Comparative Example 8

[0105] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 1, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0106] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 8. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 3 below.

TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Discharge First 40 50 60 50 50 rate of raw distillation material (%) column Second 60 50 40 50 50 distillation column Pressure of First 0.02 0.02 0.02 0.07 0.1 upper section distillation (kg/cm.sup.2g) column Second 2.5 2.5 2.5 2.5 2.5 distillation column Column First 65/95 65/95 65/95 66/96 67/97 temperature distillation (°C.) (upper column section/lower Second 105/129 105/129 105/129 105/129 105/129 section) distillation column Energy First 4.69 5.49 6.59 5.65 5.87 (Gcal/hr) distillation column Second 7.99 7.7 7.15 7.7 7.7 distillation column Recovery 4.69 5.49 4.95 5.04 5.04 amount Total 7.99 7.7 8.79 8.31 8.53 Reduction 4.04 4.33 3.24 3.72 3.5 amount Energy reduction 33.6 36.0 26.9 30.9 29.1 rate (%) Product purity (n-BAL/iso- 99.7/99.0 99.7/99.0 99.7/99.0 99.7/99.0 99.7/99.0 BAL)

TABLE-US-00002 TABLE 2 Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Discharge rate First — 50 60 40 of raw distillation material (%) column Second 100    50 40 60 distillation column Pressure of First — 0.13 0.13 0.13 upper section distillation (kg/cm.sup.2g) column Second  0.32 2.2 2.2 2.2 distillation column Column First — 68/97 68/97 68/97 temperature distillation (° C.) (upper column section/lower Second  73/100 104/127 104/127 104/127 section) distillation column Energy First — 6.37 5.84 5.46 (Gcal/hr) distillation column Second 12.03 7.41 8.38 8.76 distillation column Recovery — 4.91 4.88 5.06 amount Total 12.03 8.87 9.34 9.16 Reduction — 3.16 2.69 2.87 amount Energy — 26.3 22.4 23.9 reduction rate (%) Product purity (n-BAL/iso-BAL) 99.7/99.0 99.7/99.0 99.7/99.0 99.7/99.0

TABLE-US-00003 TABLE 3 Comparative Comparative Comparative Comparative Example 5 Example 6 Example 7 Example 8 Discharge rate First 20 80 50 50 of raw distillation material (%) column Second 80 20 50 50 distillation column Pressure of First 0.02 0.02 0.17 0.1 upper section distillation (kg/cm.sup.2g) column Second 2.5 2.5 2.5 2.2 distillation column Column First 65/95 65/95 69/97 67/96 temperature distillation (° C.) (upper column section/lower Second 105/129 105/129 105/129 102/125 section) distillation column Energy First 2.20 8.79 7.07 7.02 (Gcal/hr) distillation column Second 14.31 3.58 7.70 7.65 distillation column Recovery 2.20 2.21 4.72 4.99 amount Total 14.20 10.16 10.05 9.31 Reduction −2.17 1.87 1.98 2.35 amount Energy — 15.5 16.5 19.5 reduction rate(%) Product purity (n-BAL/iso-BAL) 99.7/99.0 99.7/99.0 99.7/99.0 99.7/99.0

[0107] As shown in Tables 1 to 3, it can be confirmed that, when the isomer of n-butyl aldehyde is separated according to each of Examples 1 to 5, a total energy consumption amount is greatly decreased, compared to the comparative examples. Accordingly, it can be confirmed that, when the raw material was separated by means of the distillation device of each of Examples 1 to 5 of the present application, an energy reduction effect of up to 36.0% is achieved, compared to the case in which the distillation device of Comparative Example 1 is used.

[0108] In addition, it can be confirmed that, as shown in the examples and the comparative examples, n-butyl aldehyde and iso-butyl aldehyde may be separated in high purity and efficiency by controlling a temperature difference between the lower section of the first distillation column and the upper section of the second distillation column and the pressures of the upper sections of the first and second distillation columns within a specific range.

[0109] In addition, as shown in Comparative Examples 5 and 6, it can be confirmed that n-butyl aldehyde and iso-butyl aldehyde may be separated in high purity and efficiency by controlling a ratio of the discharge rate into each of the first and second distillation columns within a specific range.

Example 6

[0110] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device illustrated in FIG. 2. In particular, a raw material including n-butyl aldehyde and iso-butyl aldehyde was introduced into a first distillation column with a theoretical plate number of 100.

[0111] A portion of a first column top stream discharged from an upper section of the first distillation column was refluxed in the upper section of the first distillation column via a first condenser. A portion of the remainder of the first column top stream was separated as a product including iso-butyl aldehyde and stored. A portion of a first column bottom stream discharged from a lower section of the first distillation column was refluxed in the lower section of the first distillation column via a first reboiler. A second column bottom stream discharged from the lower section of the first distillation column was introduced into a second distillation column. A third column bottom stream discharged from the lower section of the first distillation column was introduced into a heat exchanger and heat-exchanged with a second column top stream of the second distillation column introduced into the heat exchanger, followed by being refluxed in the lower section of the first distillation column via the heat exchanger. In this case, operation pressure of the upper section of the first distillation column was adjusted to 0.07 Kg/cm.sup.2g and operation temperature thereof was adjusted to 65° C. Operation temperature of the lower section of the first distillation column was adjusted to 96° C.

[0112] Meanwhile, the second column top stream discharged from an upper section of the second distillation column was introduced into the heat exchanger and heat-exchanged with the third column bottom stream. Subsequently, a portion of the second column top stream having passed through the heat exchanger and a second condenser was refluxed in the upper section of the second distillation column, and a portion of the remainder of the second column top stream was separated as a product including n-butyl aldehyde. In this case, the purity of n-butyl aldehyde was 99.9%. A fourth column bottom stream discharged from a lower section of the second distillation column was refluxed in the lower section of the second distillation column via a second reboiler, and a fifth column bottom stream discharged from the lower section of the second distillation column was separated as a product including n-butyl aldehyde. In this case, operation pressure of the upper section of the second distillation column was adjusted to 1.4 Kg/cm.sup.2g, and operation temperature thereof was adjusted to 105° C. Operation temperature of the lower section of the second distillation column was adjusted to 120° C.

[0113] N-butyl aldehyde and iso-butyl aldehyde were separated by means of the distillation device of Example 6. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 4 below.

Example 7

[0114] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0115] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 7. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 4 below.

Example 8

[0116] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 3 below.

[0117] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Example 8. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 4 below.

Comparative Example 9

[0118] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 5 below.

[0119] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 9. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 5 below.

Comparative Example 10

[0120] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 5 below.

[0121] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 10. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 5 below.

Comparative Example 11

[0122] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 5 below.

[0123] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 11. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 5 below.

Comparative Example 12

[0124] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 6 below.

[0125] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 12. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 6 below.

Comparative Example 13

[0126] N-butyl aldehyde and iso-butyl aldehyde were separated in the same manner as in Example 6, except that the operation conditions of the first and second distillation columns were changed as disclosed in Table 6 below.

[0127] N-butyl aldehyde and iso-butyl aldehyde were separated by means of a distillation device of Comparative Example 13. With regard to this, used energy amount, recovery amount, reduction amount, reduction rate, and the purity of an n-butyl aldehyde/iso-butyl aldehyde product are summarized in Table 6 below.

TABLE-US-00004 TABLE 4 Example 6 Example 7 Example 8 Pressure of First 0.07 0.07 0.1 upper section distillation (kg/cm.sup.2g) column Second 1.4 1.8 2.1 distillation column Column First 66/96 66/96 67/97 temperature distillation (° C.) (upper column section/lower Second 105/120 110/124 114/128 section) distillation column Energy First 10.91 10.91 11.45 (Gcal/hr) distillation column Second 5.71 5.82 6.01 distillation column Recovery 4.59 4.72 4.80 amount Total 12.03 12.01 12.66 Reduction 2.34 2.36 1.71 amount Energy 16.3 16.4 11.9 reduction rate (%) Product purity (n-BAL/iso-BAL) 99.9/99.3 99.9/99.3 99.9/99.3

TABLE-US-00005 TABLE 5 Comparative Comparative Comparative Example 9 Example 10 Example 11 Pressure of First 0.34 0.18 0.052 upper section distillation (kg/cm.sup.2g) column Second 0.15 1.4 1.2 distillation column Column First 73/100 69/98 66/95 temperature distillation (° C.) (upper column section/lower Second 79/97 105/120 101/116 section) distillation column Energy First 12.07 11.79 10.91 (Gcal/hr) distillation column Second 2.3 5.67 5.65 distillation column Recovery — 3.94 3.43 amount Total 14.37 13.52 13.13 Reduction — 0.85 1.24 amount Energy — 5.9 8.6 reduction rate (%) Product purity (n-BAL/iso-BAL) 99.9/99.3 99.9/99.3 99.9/99.3

TABLE-US-00006 TABLE 6 Comparative Comparative Example 12 Example 13 Pressure of First 0.11 0.3 upper section distillation (kg/cm.sup.2g) column Second 1.35 1.6 distillation column Column temperature First 67/96 72/100 (° C.) (upper distillation section/lower column section) Second 104/167 108/170 distillation column Energy First 11.5 11.9 (Gcal/hr) distillation column Second 5.60 6.32 distillation column Recovery 4.38 3.88 amount Total 12.72 14.34 Reduction 1.65 0.03 amount Energy 11.5 0.2 reduction rate (%) Product purity (n-BAL/iso-BAL) 99.9/99.3 99.9/99.3

[0128] As shown in Tables 4 to 6, it can be confirmed that, when the isomer of n-butyl aldehyde is separated according to each of Examples 6 to 8, a total energy consumption amount is greatly decreased, compared to the comparative examples. Accordingly, it can be confirmed that, when the raw material was separated by means of the distillation device of each of Examples 6 to 8 of the present application, an energy reduction effect of up to 16.4% is achieved, compared to the case in which the distillation device of Comparative Example 5 is used.

[0129] In addition, it can be confirmed that, as shown in the examples and the comparative examples, n-butyl aldehyde may be separated in high purity and efficiency by controlling a temperature difference between the lower section of the first distillation column and the upper section of the second distillation column and the pressures of the upper sections of the first and second distillation columns, within a specific range.