This is a separation example of 2,6-Diethylnaphthalene (2,6-DEN), the raw material of PEN resin to which much attention is being paid due to it being a substitute material for PET Bottles.

Generally, 2,6-DEN is obtained by the ethylization of naphthalene, but since the product of this process included isomers of 2,6-DEN as well as alkylates, the technique of purifying and separating 2,6-DEN from its isomers and other impurities became important.

Since the economically feasible separation of distillation or crystallization has been difficult, an examination of an example of 2,6-DEN separation using the New JO Chromatographic Separation System is presented.

Test Equipment: Length of Column 1500 [mm] * 12 columns

Adsorption Material: K modificated Y form Zeolite

Desorbent: Ethylbenzene

Flow Rate of Feed: 0.06 [l/l-absorption material/h]

Flow Rate of Desorbent: 0.33 [l/l-absorption material/h]

Speed Inside Bed: 16 [m/hr]

Column Switching Speed: 25 [m/h]

Separation Results

As shown in the table, the separation of 2,6-Diethylnaphthalene with high recovery rates and over 70% purity was achieved.

Furthermore, by keeping the mixing rate of 2,7-DEN, which is hard to separate in the downstream distillation process for the separation of isomers, below 1%, production of high purity 2,6-DEN has been made possible.

The example showed that the isolation of a high purity isomer which previously had been difficult, was made possible through the use of the New JO Chromatographic Separation System.

Kohei Sato, et al.: Giji idousou housiki wo mochiita jiechirunafutaren iseitaino koudo bunri seisei (High Degree Diethylnaphthalene Isomer Separation and Purification Using Simulated Moving-bed System), Kagaku kougakkai dai 28 kai syuki taikai yousisyu, 59 (1995)