Hydrogenation of diethyl adipate in a catalytic fixed-bed reactor

The vapor phase hydrogenation of diethyl adipate (DEA) was investigated using a copper chromite catalyst in a fixed-bed reactor over the temperature range of 523 to 563 K. The various products obtained during the hydrogenation reaction were identified by gas chromatography/mass spectroscopy (GC/MS) and quantified by GC. Under the conditions of the present work, the major products identified were 1,6-hexanediol, oxepane, and omega-hydroxyethyl caproate. The combined effects of reaction temperature, hydrogen pressure, and contact time on both the conversion of DEA and the selectivity to the main reaction products and various byproducts were also studied. The intrinsic kinetics of this hydrogenation were also investigated, and a suitable reaction rate equation based on a single-site Langmuir-Hinshelwood mechanism was used to interpret the integral reactor performance data. The kinetic rate equation constants were determined by nonlinear parameter estimation using the integral reactor data as the basis. The predicted concentrations of various components agreed with the experimental data within +/-7% over a reasonable range of experimental reaction conditions.