Estimation of mass transfer parameters during dehydroxylation in a large ceramic body by inverse methods

An inverse problem of the parameter estimation for the water transport during dehydroxylation in a large cylindrical ceramic body is solved. The transport is described by a standard type of non-stationary diffusion equation with a volumetric generation. The inverse problem is solved by the Levenberg-Marquardt method, with the estimated parameters being the water transfer diffusivity and water generation per unit volume. Their temperature dependencies are obtained within the dehydroxylation regime for 450 °C, 500 °C, 550 °C, and 600 °C, using experimental data from isothermal heating measurements. The activation energy of the diffusion process is estimated from the temperature dependence of the diffusivity, yielding 72.9 kJ mol−1.