Distillation method
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.
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:
wherein R 1 is a C 4 to C 12 alkyl group, and R 2 to R 4 are each independently hydrogen or a C 4 to C 12 alkyl group,
R 5 is a C 1 to C 4 alkyl group, and n is 1 to 4;
T t-2 −T b-3 ≥8° C., [Equation 1]
P 2 /P 1 ≥3.0, [Equation 2]
wherein T t-2 indicates a temperature of the second top stream, and T b-3 indicates a temperature of the third bottom stream, and
P 1 indicates a pressure of the upper section of the first distillation column in kg/cm 2 g, and P 2 indicates a pressure of the upper section of the second distillation column in kg/cm 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 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 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.