A thermo-gravimetric analysis study on the chlorination reaction of ZIRLO cladding hulls

A thermo-gravimetric analysis system for hull chlorination reaction (TGA-HC) was employed to measure weight change of ZIRLO cladding hulls in-situ during the chlorination reaction. The total flow rate (Q) experiments suggested that the chlorination reaction of ZIRLO is within the gas phase transport limited region for Q of 120 and 240 mL/min conditions. The Sharp–Hancock plot was employed to determine the most suitable geometry function, and the volumetric contraction model was identified as the best model although it is valid only in a reaction progress range of (0–0.5). The effect of chlorine partial pressure (pCl2) on the reaction rate was investigated for pCl2 of 9.21, 16.9, and 23.4 kPa, and it was identified that the chlorination rate is proportional to chlorine partial pressure on the order of (0.873). An activation energy of 7.21 kJ/mol was achieved from reaction temperature experiments, but the value was not decisive because increasing reaction temperature also affected the gas phase transport rate. Thus, the final reaction equation rate was achieved as a function chlorine partial pressure as follows: dαdt=3×(0.00738×pCl20.873)×(1−α)2/3 [Display omitted] •Chlorination reaction kinetics of ZIRLO was studied using a TGA system.•A specially designed TGA system was introduced to employ intact cladding hulls.•The volumetric contraction model was identified as a geometry function.•A reaction rate equation was proposed as a function of chlorine partial pressure.