Distillation method

Abstract

The present application relates to a distillation device. The distillation device of the present application can minimize energy loss occurring in a purification process of the olefin monomer, the solvent, and the raw material including, for example, 1-octene, iso-octene, and n-hexane, used in a polymerization process of the polyolefin elastomer, and can increase economic efficiency by isolating a high-purity product.

Claims

1. A distillation method, comprising: introducing a raw material comprising compounds represented by Formulas 1 and 2 below into a first supply port of a first distillation column, obtaining a first top stream at an upper section of the first distillation column, and separately obtaining first, second and third bottom streams at a bottom section of the first distillation column, introducing the first bottom stream into a second supply port of a second distillation column, obtaining a second top stream at an upper section of a second distillation column and obtaining fourth and fifth bottom streams at a bottom section of the second distillation column, heat-exchanging the second top stream with the third bottom stream; and isolating the compound represented by Formula 2 from the first top stream, and the compound represented by Formula 1 from the second top stream, wherein Equations 1 and 2 below are satisfied: ##STR00003## wherein R.sub.1 is a C.sub.4 to C.sub.12 alkyl group, and R.sub.2 to R.sub.4 are each independently hydrogen or a C.sub.4 to C.sub.12 alkyl group, R.sub.5 is a C.sub.1 to C.sub.4 alkyl group, and n is 1 to 4;
T.sub.t-2T.sub.b-38 C.,[Equation 1]
P.sub.2/P.sub.13.0,[Equation 2] wherein T.sub.t-2 indicates a temperature of the second top stream, and T.sub.b-3 indicates a temperature of the third bottom stream, and P.sub.1 indicates a pressure of the upper section of the first distillation column in kg/cm.sup.2 g, and P.sub.2 indicates a pressure of the upper section of the second distillation column in kg/cm.sup.2 g.

2. The method according to claim 1, wherein the compound represented by Formula 1 is at least one selected from the group consisting of 1-octene, iso-octene and a mixture thereof, and the compound represented by Formula 2 is n-hexane.

3. The method according to claim 2, wherein a content of n-hexane in the first top stream is 90% or more, and a content of 1-octene, iso-octene, or a mixture thereof in the second top stream is 90% or more.

4. The method according to claim 1, wherein the second top stream that is heat-exchanged with the third bottom stream is introduced into a second condenser, which is in fluid communication with the second distillation column, and a portion of the second top stream passing through the second condenser is introduced into the upper section of the second distillation column, and a remainder of the second top stream passing through the second condenser is introduced into a storage tank to store the compound represented by Formula 1 therein.

5. The method according to claim 1, wherein a pressure of the upper section of the first distillation column is 0.05 to 0.2 kg/cm.sup.2 g.

6. The method according to claim 1, wherein a pressure of the upper section of the second distillation column is 1.0 to 2.0 kg/cm.sup.2 g.

7. The method according to claim 1, wherein a temperature of the upper section of the first distillation column is 60 to 80 C.

8. The method according to claim 1, wherein a temperature of the lower section of the first distillation column is 120 to 145 C.

9. The method according to claim 1, wherein a temperature of the upper section of the second distillation column is 125 to 170 C.

10. The method according to claim 1, wherein a temperature of the lower section of the second distillation column is 130 to 180 C.

11. The method according to claim 1, wherein the compound represented by Formula 2 is a solvent used in polymerization of a polyolefin elastomer.

Description

DESCRIPTION OF DRAWINGS

(1) The FIGURE exemplarily illustrates a distillation device according to an embodiment of the present application.

MODES OF THE INVENTION

(2) Now, the present invention will be described in more detail with reference to examples according to the present invention and comparative examples. 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

(3) 1-Octene, iso-octene, and n-hexane were isolated by means of a distillation device illustrated in the FIGURE. In particular, a raw material including 1-octene, iso-octene, and n-hexane was introduced into a first supply port located at a 15th plate of a first distillation column with a theoretical plate number of 21.

(4) A portion of a first top stream discharged from an upper section of the first distillation column was refluxed into the upper section of the first distillation column via a first condenser. A portion of the remainder of the first top stream was isolated as a product including n-hexane and stored. A portion of a first bottom stream discharged from a lower section of the first distillation column was refluxed into the lower section of the first distillation column via a first reboiler. A second bottom stream discharged from the lower section of the first distillation column was introduced into a second supply port located at a 7.sup.th plate of a second distillation column with a theoretical plate number of 12. A third bottom stream discharged from the lower section of the first distillation column was introduced into a heat exchanger and heat-exchanged with a second top stream of the second distillation column introduced into the heat exchanger, and then was refluxed into 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 0.16 kg/cm.sup.2 g and an operation temperature thereof was adjusted to 75 C. An operation temperature of the lower section of the first distillation column was adjusted to 130 C.

(5) Meanwhile, the second top stream discharged from an upper section of the second distillation column was introduced into the heat exchanger and heat-exchanged with the third bottom stream. Subsequently, a portion of the second top stream having passed through the heat exchanger and the second condenser was refluxed into the upper section of the second distillation column, and a portion of the remainder of the second top stream was isolated as an octene-based product including 1-octene and iso-octene. In this case, the purity of each of the 1-octene and iso-octene was 94%. A fourth bottom stream discharged from a lower section of the second distillation column was refluxed into the lower section of the second distillation column via a second reboiler, and a fifth bottom stream discharged from the lower section of the second distillation column was isolated as a product for fuel including some octene-based materials and an ingredient with a high boiling point. In this case, operation pressure of the upper section of the second distillation column was adjusted to 1.4 kg/cm.sup.2 g, and an operation temperature thereof was adjusted to 155 C. An operation temperature of the lower section of the second distillation column was adjusted to 160 C.

(6) In isolating 1-octene, iso-octene, and n-hexane by means of the distillation device of Example 1, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 1 below.

Example 2

(7) 1-Octene, iso-octene, and n-hexane were isolated 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.

(8) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Example 2, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 1 below.

Example 3

(9) 1-Octene, iso-octene, and n-hexane were isolated 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.

(10) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Example 3, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 1 below.

Example 4

(11) 1-Octene, iso-octene, and n-hexane were isolated 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.

(12) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Example 4, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 1 below.

Comparative Example 1

(13) 1-Octene, iso-octene, and n-hexane were isolated 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.

(14) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Comparative Example 1, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 2 below.

Comparative Example 2

(15) 1-Octene, iso-octene, and n-hexane were isolated 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.

(16) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Comparative Example 2, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and n-hexane were as summarized in Table 2 below.

Comparative Example 3

(17) 1-Octene, iso-octene, and n-hexane were isolated 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.

(18) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Comparative Example 3, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 2 below.

Comparative Example 4

(19) 1-Octene, iso-octene, and n-hexane were isolated 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.

(20) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Comparative Example 4, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 3 below.

Comparative Example 5

(21) 1-Octene, iso-octene, and n-hexane were isolated 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.

(22) In isolating 1-octene, iso-octene, and n-hexane by means of a distillation device of Comparative Example 5, a used energy amount, a recovery amount, a reduction amount, a reduction rate, and the purities of a mixture of 1-octene and iso-octene, and an n-hexane product were as summarized in Table 3 below.

(23) TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Pressure of upper First distillation 0.16 0.13 0.15 0.05 section (kg/cm.sup.2g) column Second 1.4 1.1 1.2 1.2 distillation column Column First distillation 75/130 72/126 74/130 71/127 temperature ( C.) column (upper Second 155/160 149/155 151/157 151/157 section/lower distillation section) column Energy First distillation 0.7 0.83 0.88 0.74 (Gcal/hr) column Second 0.73 0.74 0.74 0.74 distillation column Recovery amount 0.7 0.63 0.62 0.67 Total 0.73 0.94 1.00 0.81 Reduction 0.59 0.38 0.32 0.51 amount Energy reduction 44.7 28.8 24.2 38.6 rate (%) Product purity 1-Octene + iso- 94 94 94 94 (%) octene n-Hexane 99.3 99.3 99.3 99.3

(24) TABLE-US-00002 TABLE 2 Comparative Comparative Comparative Example 1 Example 2 Example 3 Pressure of upper First distillation 0.3 0.75 0.75 section (kg/cm.sup.2g) column Second distillation 0.2 1.2 2.0 column Column First distillation 80/135 88/144 88/144 temperature ( C.) column (upper Second distillation 130/135 151/157 166/172 section/lower column section) Energy First distillation 0.73 1.73 1.73 (Gcal/hr) column Second distillation 0.59 0.74 0.96 column Recovery amount 0.45 0.45 Total 1.32 2.02 2.24 Reduction amount Energy reduction rate (%) Product purity 1-Octene + iso-octene 94 94 94 (%) n-Hexane 99.3 99.3 99.3

(25) TABLE-US-00003 TABLE 3 Comparative Comparative Example 4 Example 5 Pressure of upper First distillation 0.75 0.68 section (kg/cm.sup.2g) column Second distillation 1.23 1.15 column Column temperature First distillation 88/144 86/143 ( C.) (upper column section/lower Second distillation 152/160 151/159 section) column Energy (Gcal/hr) First distillation 1.73 1.58 column Second distillation 0.77 0.70 column Recovery amount 0.45 0.45 Total 2.05 1.83 Reduction amount Energy reduction rate (%) Product purity (%) 1-Octene + iso-octene 94 94 n-Hexane 99.3 99.3

(26) As shown in Tables 1 to 3, it can be confirmed that, when 1-octene, iso-octene, and n-hexane are isolated according to each of Examples 1 to 4, a total energy consumption amount is greatly decreased, compared to the comparative examples. Accordingly, when the raw material is isolated by means of the distillation device according to each of Examples 1 to 4 of the present application, energy reduction effect up to 44.7% can be achieved, compared to the cases in which the distillation devices according to the comparative examples are used.

(27) In addition, it can be confirmed that, as shown in the examples and the comparative examples, 1-octene, iso-octene, and n-hexane can be isolated with 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.