Details of urea decomposition in the presence of transition metal ions

Literature on kinetics of urea decomposition in aqueous solutions was reviewed for 333-373 K range. After identifying possible reactions in the targeted pH range, kinetic simulations were performed. Significant accumulation of the cyanate intermediate was observed in the pH-digestion time-temperature range that was studied. Effects of hydrolysis of metal ions and complexes forming between cations and the decomposition products were considered by incorporation of the pertinent equilibria into the simulations. Predictions on the rate of retrieval of cations from the solutions were compared against the experimental data from chemical analyses and UV/VIS.