Determination of Reaction Coefficient, Thermal Conductivity and Pore Diffusivity in Decomposition of Limestone of Different Origin

Abstract— This paper presents a method to evaluate the reaction rate coefficient, the pore diffusivity and the thermal conductivity of the lime layer in the decomposition of limestone of various origins with an analytical solution, based on the shrinking core model. Long cylindrical limestone samples with diameters greater than 20 mm were prepared and thermally decomposed in a chamber furnace at constant temperature and CO2 pressure. By weighting and simultaneous measuring of the internal temperature, the decomposition behavior of these samples was studied. The reaction rate coefficients obtained vary from 0.003 to 0.013 m/s. The thermal conductivity lies between 0.52 and 0.83 W/m/K and the effective thermal conductivity changes with a factor of 12. The evaluated values by other authors based on limestone powder lie within this range. Besides, numerical solutions have been employed to simulate the effects of the material property on the decomposition behavior.