FREMGANGSM}TE TIL FREMSTILLING AV NITRILOTRIACETONITRIL

1334991 Nitrilotriacetonitrile KNAPSACK AG 4 May 1972 [29 May 1971] 20852/72 Addition to 1303788 Heading C2C Nitrilotriacetonitrile is produced as by the process of Specification 1,303,788, with the improvement comprising recovering the acid and the excess proportion of the ammonium salt introduced together with the starting solutions into the reaction by introducing the aqueous acid phase freed from nitrilotriacetonitrile, or the mother liquor, into an evaporator, evaporating therein between 50 and 75 weight per cent of the water contained in the mother liquor, treating the resulting liquid and acid evaporation residue with ammonia so as to establish a pH value of at most 6 therein, separating oily byproducts, which may be found to precipitate, therefrom, and returning the mother liquor saturated with the ammonium salt to the primary reaction zone.