Toluenediamine is produced and separated from by-products of the reaction
by: a) hydrogenating dinitrotoluene in the presence of a catalyst, b)
separating the catalyst, water and optionally solvent from the
hydrogenation reaction mixture to give crude toluenediamine, and c)
separating by distillation the crude toluenediamine in a separating wall
column into at least four product streams P1, P2, P3 and P4. The product
stream P1 is a stream containing low boilers. The product stream P2 is a
stream containing o-toluenediamine. The product stream P3 is a stream
containing m-toluenediamine. The product stream P4 is a stream containing
high boilers and m-toluenediamine.