Extended kinetic approach to reversible thermal decomposition of solids: A universal description considering the effect of the gaseous product and the kinetic compensation effect

Water vapor effect on the physico-geometrical reaction pathway and kinetics of the multistep thermal dehydration of calcium chloride dihydrate

“…The logarithmic form of eqn (4) was used for the formal kinetic analysis comprising the isoconversional and isothermal analyses. 14 …”

“…Notably, these E a,1 values are significantly larger than that reported previously for the thermal dehydration of CC-DH to form CC-MH in a stream of dry N 2 , which stood at 72 kJ mol −1 . 31 Such an increase in the E a value, derived from the basic kinetic equation, with rising partial pressure of the gaseous product in the reaction atmosphere, is a common phenomenon in reversible thermal decomposition of solids, 11–21 often seen as a superficial variation caused by the simplified kinetic approach that neglects the effect of p (H 2 O). In the second reaction step, the average E a,2 value at p (H 2 O) = 0.8 kPa, that is, 333 kJ mol −1 , was more than four times larger than that reported previously for the thermal dehydration of CC-MH to form CC-AH in a stream of dry N 2 , that is, 82 kJ mol −1 .…”

“…Hence, a possible solution involves integrating an AF comprising both p (H 2 O) and P eq, i ( T ), denotes as h i ( p (H 2 O), P eq, i ( T )), into the basic kinetic equation. 11–21,55 …”

“…This challenge, also spanning over a century, 10 has recently been addressed by achieving a universal kinetic description of the reaction rate as a function of T , α , and the partial pressure of the gas. This was achieved by introducing an accommodation function (AF) based on the partial pressure of the gaseous product species and the equilibrium pressure of the reaction ( P eq ( T )), demonstrated in simple single-step reactions such as the thermal decomposition of metal carbonates 11–14 and hydroxides, 15–17 as well as thermal dehydration of inorganic hydrates. 18–21 Nevertheless, to enhance our comprehension of the thermal dehydration of inorganic hydrates and facilitate the design of thermochemical energy storage systems, more advanced kinetic modeling is necessary because many potential thermal dehydration reactions entail multistep processes and proceed through several intermediate hydrates.…”

Compensación cinética y termodinámica del pardeamiento no enzimático de zumos clarificados de limón

“…En La literatura reciente se pueden encontrar trabajos que aplican la compensación cinética en áreas no alimentarias. Así, Hotta & Koga (2024) lo aplican al estudio de la descomposición térmica reversible de CaCO3 en estado sólido, lo que les permite verificar que se cumple la compensación cinética y obtener los puntos isocinéticos. La pirolisis es una tecnología ampliamente utilizada para convertir la biomasa en biocombustibles en estado líquido o gaseoso (Jankovic et al, 2023;Wang et al, 2024), aunque en estos procesos se utilizan temperaturas sumamente superiores a las utilizadas en los procesos alimentarios convencionales.…”