Effect of calcium dispersion and graphitization during high-temperature pyrolysis of beech wood char on the gasification rate with CO2

This paper presents thermal deactivation of beech wood chars during secondary pyrolysis in a drop-tube reactor. Pyrolysis temperature was varied between 1000 °C and 1600 at constant residence time 200 ms. The effect conditions on initial conversion rate R0 gasification, graphitization the carbon matrix ash morphology investigated. Gasification experiments for determination were conducted thermogravimetric analyzer using pure CO2 750 isothermal conditions. A linear decrease observed 1400 °C. However, strong increase encountered. Micropore surface area showed no correlation with gasification CO2. Graphitization determined X-ray diffraction Raman spectroscopy suggesting growth aromatic clusters graphite-like structures increasing temperatures up to Furthermore, CaO dispersion analyzed quantitatively qualitatively temperature-programmed reaction 300 as well SEM/TEM. DCaO decreases steadily whereas can be °C, which is good accordance development function temperature. SEM/TEM images indicate formation thin layer that presumably responsible this When excluding catalytic activity via ratio DCaO?1, degree has negative influence char reactivity