4. Conclusions The gasification kinetics and influence factor of semi-char-CO2 gasification were investigated. The carbon conversion of semichar increases with the decrease of particle size. The gasification reactivities of semi-chars can be ranked as 400 C semichar > 300 C semi-char > 500 C semi-char > 600 C semi-char. The semi-char obtained in the H2 atmosphere has the best reactivity, while the semi-char obtained in the CO2 pyrolysis atmosphere has the worst reactivity. The volatile matter, FC and ash content are found to be important factors that affect the gasification reactivities of chars. The best model for describing the bio-char was RPM. Ac