Transformation analysis of thermochemical reactor based on thermophysical properties of graphite-MnCl2 complex

Abstract

Transformation of the graphite-MnCl2 complex/ammonia system was investigated in a thermochemical reactor through numerical simulation. Thermophysical properties such as effective thermal conductivity and gas permeability were measured for the reactive medium with a bulk density of 100-250 kg m(-3) and the values obtained were in the range of 14.0-25.6 W m(-1) K-1 and (8.0 x 10(-15))-10(-12) m(2) respectively. A model for the thermochemical reactor was developed on a macroscopic scale, and then the measured thermophysical properties were used in the model equations. The results of the simulation showed that, when the operating pressure was <1.0 bar and the bulk density of the reactive media was >200 kg m(-3), the rate of global conversion was significantly impeded by the mass-transfer limitation. The absence of a distinctive heat front in the reactor shows that heat transfer is not a limiting factor with the graphite-MnCl2 complex.