Sample‐Controlled analysis under high pressure for accelerated process studies

Abstract

The potential of controlled rate thermal analysis (CRTA) for studying high‐pressure gas‐solid processes has been evaluated. CRTA is a type of smart temperature program based on a feedback system that uses any experimental signal related to the process evolution for commanding the temperature evolution. In this work, an instrument that uses the gravimetric signal for CRTA control has been designed and used for the study of two high‐pressure gas‐solid reactions: the highly exothermic thermal oxidation of TiC under high pressure of oxygen and the reduction in Fe2O3 under high pressure of hydrogen. Advantages of CRTA for discriminating overlapping processes and appraising kinetic reaction mechanisms are shown.

Development of a high-pressure thermobalance working under constant rate thermal analysis

“…[1][2][3][4][5] Nevertheless, the acceleration induced by the gas pressure might produce significant heat and mass transfer gradients and, therefore, the experimental results might not be representative of the process. [6][7][8][9] Additionally, if the amount of heat released or absorbed by a reaction is significant, it could cause significant self-heating of self-cooling of the sample, especially if the process takes place over a short period of time. Taking into consideration all these limitations, obtaining reliable experimental data for performing kinetic or thermodynamic analysis under high gas pressure is quite challenging for many processes.…”