Patent ID: 8764946

Claim:
A dividing wall distillation column comprising a condenser, a reboiler and a main column having a dividing wall, wherein the main column is divided into a column-top zone, an upper feed zone, an upper outflow zone, a lower feed zone, a lower outflow zone and a column-bottom zone, a raw material flows in a middle inflow plate in which the upper feed zone and the lower feed zone come in contact with each other, a low boiling point component flows out from the column-top zone, a high boiling point component flows out from the column-bottom zone, and a middle boiling point component flows out through a middle outflow plate in which the upper outflow zone and the lower outflow zone come in contact with each other, wherein the raw material has a 2-ethyl hexanol content of 90% by weight or more, and the middle boiling point component is 2-ethyl hexanol, wherein the number of plates provided respectively in the column-top zone, the upper feed zone, the upper outflow zone, the lower feed zone, the lower outflow zone and the column-bottom zone is in a range of 80 to 145% of a theoretical plate number, as calculated from a distillation curve, wherein a length of the dividing wall is in a range of 30 to 85% of the total theoretical plate number in the column-top zone, the upper feed zone, the lower outflow zone and the column-bottom zone, as calculated from the distillation curve, wherein (i) when the pressure is at a pressure of 16.671 kPa: a temperature of the column-top zone is in a range of 75 to 85° C., a temperature of the column-bottom zone is in a range of 145 to 160° C., and a temperature of the middle outflow plate is in a range of 130 to 140° C., (ii) when the pressure is out of a pressure of 16.671 kPa: the temperature of the column-top zone is in a range of a lower temperature limit (T 1α ) to an upper temperature limit (T 2α ), which follows the following Equation 1, the temperature of the column-bottom zone is in a range of a lower temperature limit (T 1β ) to an upper temperature limit (T 2β ), which follows the following Equation 2, the temperature of the middle outflow plate is in a range of a lower temperature limit (T 1χ ) to an upper temperature limit (T 2χ ), which follows the following Equation 3, Lower limit: T 1α =114.5099 *P 0.2439 Upper limit: T 2α =123.4949 *P 0.2149 Equation 1 (wherein T 1α and T 2α represent temperatures (° C.); P represents a pressure (kPa), provided that 0.981≦P≦980.665 and P≠16.671) Lower limit: T 1β =192.1386 *P 0.1548 Upper limit: T 2β =206.5980 *P 0.1405 Equation 2 (wherein T 1β and T 2β represent temperatures (° C.); P represents a pressure (kPa), provided that 0.981≦P≦980.665 and P≠16.671) Lower limit: T 1χ =157.7845 *P 0.1034 Upper limit: T 2χ =167.6350 *P 0.096 Equation 3 (wherein T 1χ and T 2χ represent temperatures (° C.); P represents a pressure (kPa), provided that 0.981≦P≦980.665 and P≠16.671).