THERMAL AND CHEMICAL BEHAVIOR OF SOLID PARTICLES DURING ENDOTHERMIC DECOMPOSITION UNDER THE EFFECT OF EXTERNAL HEAT-FLUX

The purpose of the present paper is an experimental and theoretical st udy of the behaviour of solid particles undergoing an endothermic reac tion under the effect of an external heat flux. It is shown that after a pure heating period, the reaction occurs under quasi isothermal con ditions as soon as the particles have reached a certain temperature T( R). T(R) is normally much lower than the external heat source temperat ure. The variations of T(R) and the effect of temperature stabilizatio n are studied as a function of solid properties, chemical reaction (ki netic and thermodynamic), and heat transfer conditions. Data obtained from measurements of the decarbonation reaction of NaHCO3 agree well w ith predictions of the theoretical study.