Influences of solvents on the production of high purity 2,6-dimethylnaphthalene via catalytic isomerization and adsorptive separation

Abstract

Influences of seven solvents – benzene, toluene, ethylbenzene (EB), p-diethylbenzene (pDEB), o-xylene, m-xylene, and p-xylene – on the production of high purity 2,6-dimethylnaphthalene (DMN) via catalytic isomerization and adsorptive separation of the 2,6-triad DMNs were investigated. The solvents act as a reaction media for the isomerization and a desorbent for the adsorption. From the catalytic testing in a batch reactor over a H-beta catalyst and the adsorption using a pulse test technique over Na-faujasite adsorbents, the results indicate that the solvent characteristics, e.g. dipole moment, relative π-electron basicity, play very important roles on both processes. And, the best catalytic isomerization and adsorption system can be demonstrated if an appropriate solvent is used. Among the employed solvents, appropriate solvents for either the isomerization or adsorption were identified in this study. However, only toluene shows a possibility for being used to produce high purity 2,6-DMN via the combination of the isomerization and adsorption technique.