this invention relates to an improvement in a process for hydrogenating a nitroaromatic composition namely dinitrotoluene by contacting the dinitrotoluene with hydrogen in a reactor employing a monolith catalyst system . broadly the improvement resides in the continuous , essentially solventless , adiabatic hydrogenation of dinitrotoluene to toluenediamine in a plug flow reactor system incorporating the monolith catalyst . the process generally comprises the steps : introducing a feedstock comprised of dinitrotoluene and reaction product components continuously into the reactor and said feedstock having less that 30 % by weight of a solvent , carrying out the hydrogenation of dinitrotoluene to toluenediamine under adiabatic conditions ; and , continuously removing hydrogenated reaction product from the reactor .