| 초록 |
For the chemical-looping combustion (CLC), an alternative gas combustion by redox of metal oxide as oxygen carrier, NiO, Fe2O3, Mn2O3, and CuO for oxygen carriers supported on bentonite were selected as looping materials. The reactivities of oxygen carrier particles were characterized by the kinetic equations based on the solid-state reaction models, namely, diffusion-controlled, phase-boundary-controlled and Avrami-Erofe'ev phase change models, by Sharp and Hancock method. The properties of oxygen carrier particles before and after reaction were investigated by SEM, XRD and Ar-BET to prove reaction mechanisms of oxygen carriers. The surface area and pore volume are increased in the range of 0.06-1.07 m2/g and 0.2-1.0 mm3/g before and after reduction of each particle, respectively. The phase-boundary-controlled reaction model is found to be represented well for each reaction of most of oxygen carriers. The activation energies and pre-exponential factors were determined from Arrhenius plot, respectively. |
