Gasification Reaction with CO2 of Bituminous Char

The gasification characteristics of different coals and their chars with CO2 at high temperatures were investigated by TG-FTIR.The chars were prepared under low(LHR) and high heating rates(HHR) pyrolysis conditions.The gas products were analyzed on-line during the gasification of different coals and their chars.The pore structure characteristics and elemental components of resulting chars were studied.The results showed that gasification rate of coal chars increased with rising temperature and then decreased.The activation energies increased when the pyrolysis and gasification temperature increased.The characteristics of CH4 and CO releases from chars are similar to those from coals,but the concentration of CH4 released from coals was 2 magnitudes greater than that from chars,and the concentration of CH4 released from high chars was higher than that from low chars.The BET surface area of chars was small(less than 2 m2/g except for SF-SP1200),the gasification reactivity of HHR chars was better than those of LHR chars.