Production of tetralin and tetralone

The hydrogenation of naphthalene to tetralin is analogous to the hydrogenation of benzene to produce cyclohexane. The reaction can be carried out in the liquid phase with nickel catalysts at 200 °C and 10 to 15 bar hydrogen pressure. The jFeedstock is desulfurized naphthalene, which can be obtained by treatment of crude naphthalene with sodium. 

World production of tetralin is around 25,000 tpa. In addition to the main application already described - the production of 1-tetralone (see Chapter 9.3.3.1), -tetralin is also used as a solvent. An earlier application as a hydrogen donor in coal hydrogenation is of no technical significance nowadays, but it is frequently carried out as a model reaction. 

The oxidation of tetralin leads to the hydroperoxide, which can be split into 1-tetralone and 1-tetralol. Dehydrogenation of tetralone and tetralol takes place in two stages, to avoid the possible dehydration of tetralol on the platinum catalyst. In the first stage, tetralol is dehydrogenated to tetralone in the gas phase in the presence of hydrogen at 200 to 325 °C and nickel or copper catalysts in the second stage, dehydrogenation on the platinum catalyst at 350 to 400 °C produces 1-naphthol. 

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