Removal of Phenol from Wastewaters by Catalytic Hydrogenation with Activated Carbon-Supported Catalyst

摘要

The hydrogenation of phenol in aqueous phase over commercial and prepared Pd/C catalysts has been studied in a continuous fixed bed reactor. Experiments were carried out using 0.5 g of catalyst, 1,000 ppm phenol solution and a hydrogen flow rate of 60 mL/min. The ranges studied for temperature and phenol solution flow rate were 130-170°C and 0.25-1.5 mL/min, respectively. Commercial Pd/C catalyst showed an optimal temperature for phenol conversion at 150°C at 9.0 bar. Phenol conversion, selectivity and yield towards cyclohexanol were enhanced at high space time. Pd/C catalysts were prepared with different load of Pd using PdCl2, PdNO3 and Pd(CH3COO)2 as precursors. For these catalysts, optimal calcination and reduction temperatures for cyclohexanol selectivity and yield were found at 250 and 150°C, respectively. The ecotoxicity of phenol solution and the resulting reaction products were measured, these last showing lower toxicity values.