abstract |
Process for hydrogenating toluenediamine (TDA) tar containing TDA and high boilers relative to TDA, including the step of contacting the toluenediamine tar with a heterogeneous hydrogenation catalyst comprising at least one metal selected from the group consisting of Ni, Co, Ru, Pd, Pt on at least one catalyst support selected from the group consisting of carbon, TiO2 and ZrO2, and with hydrogen under hydrogenating conditions. |