Ammonia Production via a Two-Step Al₂O₃/AlN Thermochemical Cycle. 2. Kinetic Analysis

Abstract

The production of ammonia via a two-step cyclic process is considered, consisting of an endothermic carbo-reduction of Al 2 O 3 in a N 2 atmosphere to form AlN, followed by exothermic steam-hydrolysis of AlN to produce NH 3 and to reform Al 2 O 3 . The chemical kinetics of both steps were experimentally investigated by thermogravimetry and gas chromatography, without added catalysts and under external supply of process heat. Rate laws and the corresponding Arrhenius kinetic parameters were determined by applying the unreacted core model for the AlN production and the shrinking core model for the AlN hydrolysis.