A new method of the multiple rate iso-temperature was used to define the most probable mechanism g(α) of a reaction; the iterative iso-conversional procedure has been employed to estimate apparent activation energy Ea, the pre-exponential factor A was obtained on the basis of Ea and g(α). In this new method, the thermal analysis kinetics triplet of dehydration of calcium oxalate monohydrate is determined,
which apparent activation energy Ea is 82.83 kJ mol-1, pre-exponential factor A is 1.142105-1.235105 s-1, the most probable mechanism belongs to phase boundary reaction Rn with integral form g(α)=1-(1-α)n and differential form f(α)=n(1-α)1-(1/n), where accommodation factor n=2.40-1.40.
Reliable kinetic information for thermal analysis kinetic triplets can be determined by the comparative method: (1) An iterative
procedure or the KAS method had been established to obtain the reliable value of activation energy Ea of a reaction. (2) A combined method including Coats-Redfern integral equation and Achar differential equation was put forward
to confirm the most probable mechanism of the reaction and calculate the pre-exponential factor A. By applying the comparative
method above, the thermal analysis kinetic triplets of the dehydration of CaC2O4H2O were determined, which apparent activation energy: 813 kJ mol-1, pre-exponential factor: 4.51106-1.78108 s-1, the most probable mechanism function: f(α)=1 or g(α)=α, which the kinetic equation of dehydration is dα/dt=Ae-Ea/RT.