Heat effects of NTO synthesis in nitric acid solution

The heat effects in the case of manufacture process of nitration 1,2,4-triazol-5-one (TO) in nitric acid solution were distinguished and determined using the calorimeters of DSC200F3, C80 and E856; the influence of these heats on the total exothermic effect during manufacture process was examined. Five kinds of thermal effects were differentiated and measured: the heat of process of dosing TO (Δ H TO,dosing ), the heat of dissolution TO (Δ H TO,dissolution ), the heat of reaction (Δ H r ), the heat of crystallization of NTO (Δ H NTO,crystallization ) and the heat ( Δ H_HNO_3 ) caused by changes in concentration of nitric acid. The data on dissolution heats of TO and NTO in nitric acid with different concentrations in the 0–98.4