Distillation device

Abstract

The present application relates to a distillation device. When a feedstock containing acetone and methanol is separated using a distillation device according to the present application, a methanol removal distillation column may be located at a position for easily separating methanol to solve a problem due to accumulation of methanol in the process and to lower the methanol content in the acetone product, and thus the lifetime of catalysts can be extended, and moreover, methanol can be removed with good efficiency from a flow of the lower part of the distillation column obtaining the final acetone product by using only the conventional phase separator and one methanol removal distillation column further installed, so that the acetone product obtained from the upper part of the distillation column obtaining the acetone product can be obtained in high purity and the operating cost and the equipment cost of equipments can be greatly reduced.

Claims

1. A distillation device which comprises a first distillation unit comprising a first condenser, a first reboiler and a first distillation column; a phase separator; and a second distillation unit comprising a second condenser, a second reboiler and a second distillation column located between said first distillation column and said phase separator and fluidically connected to said first distillation column and said phase separator, wherein a feedstock comprising a first compound, a second compound being capable of forming an azeotrope with said first compound and water, flows into said first distillation column, and the feedstock introduced into said first distillation column is divided into a first top flow discharged from a top region of said first distillation column and a first bottom flow discharged from a bottom region of said first distillation column, respectively, and discharged, wherein said first top flow flows into said first condenser and some or all of the first top flow passing through said first condenser is refluxed to the top region of said first distillation column, and a portion of said first bottom flow flows into said first reboiler and a portion of said bottom flow passing through said first reboiler is refluxed to the bottom region of said first distillation column, wherein a remaining portion of said first bottom flow flows into said second distillation column, and the remaining portion of said first bottom flow introduced into said second distillation column is divided into a second top flow discharged from a top region of said second distillation column and a second bottom flow discharged from a bottom region of said second distillation column, respectively, and discharged, wherein said second top flow flows into said second condenser and some or all of the second top flow passing through said second condenser is refluxed to the top region of said second distillation column, and a portion of said second bottom flow flows into said second reboiler and a portion of said second bottom flow passing through said second reboiler is refluxed to the bottom region of said second distillation column, wherein a remaining portion of said second bottom flow flows into said phase separator, and the remaining portion of said second bottom flow introduced into said phase separator is divided into an organic substance-containing component and a water-containing component in said phase separator, and discharged, wherein said first top flow comprises the first compound and the second compound, and said first bottom flow comprises the first compound, the second compound, and a substance having a boiling point higher than that of said second compound, wherein said second top flow comprises the first compound and the second compound, and said second bottom flow comprises a substance having a boiling point higher than that of said second compound, wherein the content of said second compound in said first top flow is 0.002 to 0.1 parts by weight relative to 100 parts by weight of the total components contained in said first top flow, and wherein the first compound is acetone, wherein the second compound is methanol, wherein the distillation device further comprises a cooling device located between the second distillation column and the phase separator, wherein the remaining portion of the second bottom flow flows into said phase separator after being introduced into said cooling device and cooled, wherein a temperature of the top region of the second distillation column is 40 to 70 C. and a pressure of the top region of the second distillation column is from 0.6 to 0kgf/cm.sup.2g, and wherein a temperature of the bottom region of the second distillation column is 70 to 95 C. and a pressure of the bottom region of the second distillation column is 0.4 to 0kgf/cm.sup.2g.

2. The distillation device according to claim 1, wherein the content of said second compound in the second top flow is 0.01 to 0.5 parts by weight relative to 100 parts by weight of the total components contained in said second top flow.

3. The distillation device according to claim 1, wherein the temperature of the cooled second bottom flow introduced into the phase separator is 50 to 90 C.

4. The distillation device according to claim 1, wherein the organic substance-containing component comprises one or more selected from the group consisting of aliphatic aldehyde, alpha-methylstyrene, water and cumene.

5. The distillation device according to claim 1, wherein the water-containing component comprises the first compound, the second compound and water.

6. The distillation device according to claim 1, further comprising a reactor; a neutralizer; and a third distillation unit comprising a third condenser, a third reboiler and a third distillation column, wherein the water-containing component discharged from the phase separator and the feedstock containing the first compound and the second compound, discharged from said reactor, flow into the neutralizer, and the feedstock containing the first compound and the second compound discharged from the neutralizer flows into the third distillation column, wherein the feedstock introduced into said third distillation column is divided into a third top flow discharged from a top region of said third distillation column and a third bottom flow discharged from a bottom region of said third distillation column, respectively, and discharged, wherein said third top flow flows into said third condenser and a portion of the third top flow passing through said third condenser is refluxed to the top region of said third distillation column, and a portion of said third bottom flow flows into said third reboiler and a portion of said third bottom flow passing through said third reboiler is refluxed to the bottom region of said third distillation column, and wherein a remaining portion of said third top flow flows into the first distillation column, and a portion of the first top flow flows into said reactor.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a diagram schematically showing a distillation device according to one embodiment of the present application.

(2) FIG. 2 is a Txy diagram of a mixture of acetone and methanol under a pressure of 1 kgf/cm.sup.2g, and FIG. 3 is a Txy diagram of a mixture of acetone and methanol at a pressure of 10 kgf/cm.sup.2g.

(3) FIGS. 4 to 7 are Txy diagrams of a mixture of water and methanol under each pressure of 2 kgf/cm.sup.2g, 1 kgf/cm.sup.2g, 0 kgf/cm.sup.2g and 0.5 kgf/cm.sup.2g.

(4) FIG. 8 is a diagram schematically showing a distillation device according to another embodiment of the present application.

(5) FIG. 9 is a diagram schematically showing a distillation device according to another embodiment of the present application.

(6) FIG. 10 is a diagram schematically showing a distillation device according to another embodiment of the present application.

(7) 10: first distillation unit 100: first distillation column

(8) 110: first condenser 120: first reboiler

(9) 20: second distillation unit 200: second distillation column

(10) 210: second condenser 220: second reboiler

(11) 30: third distillation unit 300: second distillation column

(12) 310: third condenser 320: third reboiler

(13) 40: phase separator 50: reactor

(14) 60: neutralizer 70: cooling device

(15) F.sub.1: feedstock comprising a first compound, a second compound capable of forming an azeotrope with the first compound, and water

(16) F.sub.1top: first top flow F.sub.1btm: first bottom flow

(17) F.sub.2: flow introduced into the second distillation column

(18) F.sub.2top: second top flow F.sub.2btm: second bottom flow

(19) F.sub.3: feedstock comprising the first compound and the second compound discharged from the neutralizer

(20) F.sub.3top: third top flow F.sub.3btm: third bottom flow

(21) F.sub.org: organic substance-containing component F.sub.aqu: water-containing component

MODE FOR INVENTION

(22) Hereinafter, the present invention will be described in more detail through Examples complying with the present invention and Comparative Examples uncomplying with the present invention, but the scope of the present invention is not limited by the proposed examples.

EXAMPLE 1

(23) Acetone and methanol were separated using the distillation device of FIG. 8.

(24) Specifically, a feedstock containing 55% by weight of acetone, 22% by weight of cumene, 4% by weight of alpha-methylstyrene, 0.03% by weight of methanol, and 0.14% by weight of a high boiling point component was introduced into the first distillation column having a number of theoretical stages of 65 at a temperature of 88 C. and a flow rate of 43,000 kg/hr.

(25) The first top flow discharged from the top region of the first distillation column passed through the first condenser and a portion was refluxed to the top region of the first distillation column. The remaining portion of the first top flow was separated and stored as a product comprising 99.8% by weight of acetone and 0.02% by weight of methanol, and the first bottom flow discharged from the bottom region of the first distillation column passed through the first reboiler, and a portion was refluxed to the bottom region of the first distillation column and the remaining portion was introduced into the second distillation column. In this case, the operating pressure of the first distillation column top region was adjusted to 0.44 kgf/cm.sup.2g, the operating temperature was adjusted to 40 C., the operating pressure of the first distillation column bottom region was adjusted to 0.12 kgf/cm.sup.2g, and the operating temperature was adjusted to be 89 C.

(26) Furthermore, the second top flow discharged from the top region of the second distillation column passed through the second condenser, and a portion was refluxed to the top region of the second distillation column and the remaining portion was separated as a product comprising 54% by weight of acetone and 2% by weight of methanol. A portion of the second bottom flow discharged from the bottom region of the second distillation column was refluxed to the bottom region of the second distillation column through the second reboiler and the remaining portion was cooled through the cooling device and then introduced into the phase separator. In this case, the operating pressure of the top region of the second distillation column was adjusted to 5 kgf/cm.sup.2g, the operating temperature was adjusted to be 114.1 C., the operating pressure of the bottom region of the second distillation column was adjusted to 5.14 kgf/cm.sup.2g, and the operating temperature was adjusted to be 136.5 C. Also, the second bottom flow cooled through the cooling device was introduced into the phase separator at a temperature of 52 C.

(27) In the phase separator, an organic substance-containing component comprising 83% by weight of cumene and 17% by weight of alpha-methylstyrene and a water-containing component comprising 99% by weight of water, 0.0002% by weight of acetone and 0.0604% by weight of methanol were separated and discharged, and the water-containing component was introduced into the neutralizer and introduced into the third distillation column together with the reaction product of the cumene oxidation reactor introduced into the neutralizer.

(28) In addition, the third top flow discharged from the top region of the third distillation column passed through the third condenser, and a portion was refluxed to the top region of the third distillation column and introduced into the first distillation column A portion of the third bottom flow discharged from the bottom region of the third distillation column was refluxed to the bottom region of the third distillation column via the third reboiler and the remaining portion was separated as a product comprising pure phenol. In this case, the operating pressure of the third distillation column was adjusted to 0.38 kgf/cm.sup.2g, the operating temperature was adjusted to be 120 C., the operating pressure of the bottom of the third distillation column was adjusted to 0.82 kgf/cm.sup.2g, and the operating temperature was adjusted to be 204 C.

(29) Meanwhile, a portion of the first top flow of the first distillation column was circulated to the reactor.

(30) In the case of separating acetone and methanol using the distillation device of Example 1, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

EXAMPLE 2

(31) Acetone and methanol were separated by the same method as Example 1, except that the operating conditions of the second distillation column were changed as in Table 1 below.

(32) In the case of separating acetone and methanol using the distillation device of Example 2, the used amount of energy in first and second reboilers and the removal rate of methanol were shown in Table 1 below.

EXAMPLE 3

(33) Acetone and methanol were separated using the distillation device of FIG. 9.

(34) Specifically, a feedstock containing 55% by weight of acetone, 22% by weight of cumene, 4% by weight of alpha-methylstyrene, 0.03% by weight of methanol, and 0.14% by weight of a high boiling point component was introduced into the first distillation column having a number of theoretical stages of 65 at a temperature of 88 C. and a flow rate of 43,000 kg/hr.

(35) The first top flow discharged from the top region of the first distillation column passed through the first condenser and a portion was refluxed to the top region of the first distillation column. The remaining portion of the first top flow was separated and stored as a product comprising 99.8% by weight of acetone and 0.02% by weight of methanol, and the first bottom flow discharged from the bottom region of the first distillation column passed through the first reboiler, and a portion was refluxed to the bottom region of the first distillation column and the remaining portion was introduced into the phase separator. In this case, the operating pressure of the first distillation column top region was adjusted to 0.44 kgf/cm.sup.2g, the operating temperature was adjusted to 40 C., the operating pressure of the first distillation column bottom region was adjusted to 0.12 kgf/cm.sup.2g, and the operating temperature was adjusted to be 89 C.

(36) In the phase separator, an organic substance-containing component comprising 82% by weight of cumene and 17% by weight of alpha-methylstyrene and a water-containing component comprising 99% by weight of water, 0.2% by weight of acetone and 0.0643% by weight of methanol were separated and discharged, and the water-containing component was introduced into the second distillation column.

(37) Furthermore, the second top flow (F.sub.2top) discharged from the top region of the second distillation column passed through the second condenser, and a portion was refluxed to the top region of the second distillation column and the remaining portion was separated as a product comprising 50% by weight of acetone and 14% by weight of methanol. A portion of the second bottom flow discharged from the bottom region of the second distillation column was refluxed to the bottom region of the second distillation column through the second reboiler and the remaining portion was introduced into the neutralizer and introduced into the third distillation column together with the reaction product of the cumene oxidation reactor introduced into the neutralizer. In this case, the operating pressure of the top region of the second distillation column was adjusted to 0.4 kgf/cm.sup.2g, the operating temperature was adjusted to be 47.9 C., the operating pressure of the bottom region of the second distillation column was adjusted to 0.26 kgf/cm.sup.2g, and the operating temperature was adjusted to be 92.0 C.

(38) The third top flow discharged from the top region of the third distillation column passed through the third condenser, and a portion was refluxed to the top region of the third distillation column and introduced into the first distillation column. A portion of the third bottom flow discharged from the bottom region of the third distillation column was refluxed to the bottom region of the third distillation column via the third reboiler and the remaining portion was separated as a product comprising pure phenol. In this case, the operating pressure of the third distillation column was adjusted to 0.38 kgf/cm.sup.2g, the operating temperature was adjusted to be 120 C., the operating pressure of the bottom of the third distillation column was adjusted to 0.82 kgf/cm.sup.2g, and the operating temperature was adjusted to be 204 C.

(39) Meanwhile, a portion of the first top flow of the first distillation column was circulated to the reactor.

(40) In the case of separating acetone and methanol using the distillation device of Example 3, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

EXAMPLE 4

(41) Acetone and methanol were separated using the distillation device of FIG. 10.

(42) Specifically, a feedstock containing 55% by weight of acetone, 22% by weight of cumene, 4% by weight of alpha-methylstyrene, 0.03% by weight of methanol, and 0.14% by weight of a high boiling point component was introduced into the first distillation column having a number of theoretical stages of 65 at a temperature of 88 C. and a flow rate of 43,000 kg/hr.

(43) The first top flow discharged from the top region of the first distillation column passed through the first condenser and a portion was refluxed to the top region of the first distillation column. The remaining portion of the first top flow was separated and stored as a product comprising 99.8% by weight of acetone and 0.02% by weight of methanol, and the first bottom flow discharged from the bottom region of the first distillation column passed through the first reboiler, and a portion was refluxed to the bottom region of the first distillation column and the remaining portion was cooled through the cooling device and then introduced into the phase separator. In this case, the operating pressure of the first distillation column top region was adjusted to 0.44 kgf/cm.sup.2g, the operating temperature was adjusted to 40 C., the operating pressure of the first distillation column bottom region was adjusted to 0.12 kgf/cm.sup.2g, and the operating temperature was adjusted to be 89 C. Also, the first bottom flow cooled through the cooling device was introduced into the phase separator at a temperature of 52 C.

(44) In the phase separator, an organic substance-containing component comprising 82% by weight of cumene and 17% by weight of alpha-methylstyrene and a water-containing component comprising 99% by weight of water, 0.2% by weight of acetone and 0.0672% by weight of methanol were separated and discharged, and the water-containing component was introduced into the second distillation column.

(45) Furthermore, the second top flow (F.sub.2top) discharged from the top region of the second distillation column passed through the second condenser, and a portion was refluxed to the top region of the second distillation column and the remaining portion was separated as a product comprising 42% by weight of acetone and 11% by weight of methanol. A portion of the second bottom flow discharged from the bottom region of the second distillation column was refluxed to the bottom region of the second distillation column through the second reboiler and the remaining portion was introduced into the neutralizer and introduced into the third distillation column together with the reaction product of the cumene oxidation reactor introduced into the neutralizer. In this case, the operating pressure of the top region of the second distillation column was adjusted to 0.5 kgf/cm.sup.2g, the operating temperature was adjusted to be 45.7 C., the operating pressure of the bottom region of the second distillation column was adjusted to 0.36 kgf/cm.sup.2g, and the operating temperature was adjusted to be 88.3 C.

(46) The third top flow discharged from the top region of the third distillation column passed through the third condenser (310), and a portion was refluxed to the top region of the third distillation column and introduced into the first distillation column. A portion of the third bottom flow discharged from the bottom region of the third distillation column was refluxed to the bottom region of the third distillation column via the third reboiler and the remaining portion was separated as a product comprising pure phenol. In this case, the operating pressure of the third distillation column was adjusted to 0.38 kgf/cm.sup.2g, the operating temperature was adjusted to be 120 C., the operating pressure of the bottom of the third distillation column was adjusted to 0.82 kgf/cm.sup.2g, and the operating temperature was adjusted to be 204 C.

(47) Meanwhile, a portion of the first top flow of the first distillation column was circulated to the reactor.

(48) In the case of separating acetone and methanol using the distillation device of Example 4, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

COMPARATIVE EXAMPLE 1

(49) Acetone and methanol were separated by the same method as Example 1, except that the remaining portion of the first bottom flow discharged from the bottom region of the first distillation column was directly introduced into the phase separator without passing through the second distillation column.

(50) In the case of separating acetone and methanol using the distillation device of Comparative Example 1, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

COMPARATIVE EXAMPLE 2

(51) Acetone and methanol were separated by the same method as Example 3, except that the operating conditions of the second distillation column were changed as Table 1 below.

(52) In the case of separating acetone and methanol using the distillation device of Comparative Example 2, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

COMPARATIVE EXAMPLE 3

(53) Acetone and methanol were separated by the same method as Example 4, except that the operating conditions of the second distillation column were changed as Table 1 below.

(54) In the case of separating acetone and methanol using the distillation device of Comparative Example 3, the operating conditions of the second distillation column, the heat quantity used in the second reboiler, and the removal rate of methanol were shown in Table 1 below.

(55) TABLE-US-00001 TABLE 1 Example Comparative Example 1 2 3 4 1 2 3 Removal rate of methanol 11% 80% 75% 76% 60% 61% Heat quantity used in the second 1.00 1.00 1.00 1.00 1.00 1.00 reboiler (Gcal/hr) Top pressure of the second 5.0 0.3 0.4 0.5 5.0 1.0 distillation column (kgf/cm.sup.2g) Top temperature of the second 114.1 46.1 47.9 45.7 117.0 81.3 distillation column ( C.) Bottom pressure of the second 4.14 0.16 0.26 0.36 5.14 1.14 distillation column (kgf/cm.sup.2g) Bottom temperature of the second 136.5 72.2 92 88.3 159.2 122.2 distillation column ( C.)