| 초록 |
Terephthalic acid (TPA) has become an important, fast-growing chemical. Nowadays, most of TPA used worldwide is produced by the catalytic oxidation of p-xylene that achieves 98% conversion of p-xylene and 95mol-% yield of TPA. This process, however, has some disadvantages. Recently, sub- or supercritical water process was developed to overcome these disadvantages for the production of TPA. In this study, partial oxidation of p-xylene to TPA was performed in the Hastelloy-C batch reactor without a catalyst in sub- or near-critical water. Hydrogen peroxide was used as oxidant for partial oxidation of p-xylene. The loaded amount of hydrogen peroxide was the most important parameter to control the proceeding limit of partial oxidation of p-xylene, while the temperature and pressure, determining the thermodynamic state of water, was the most important parameter for determining the reaction pathway and the reaction rate. We confirmed existence of 4-hydroxymethyl benzaldehyde as an intermediate and proposed new reaction pathway through p-cresol. Reaction pathway was verified and corrected for partial oxidation of p-xylene without a catalyst through HPLC analysis. |
