Abstract
Coal chars produced in the three pyrolysis conditions were gasified with pure CO_2 at a temperature of 1173K and with air at 773K. Pore structures of the gasified chars were investigated by gas-adsorption methods, and then pore surface area and pore size distributions were calculated. The increase of CO_2 surface area in an initial stage of gasification appeared greater for the higher rank coal than for the lower. A significant enlargement of pore radius was found for the char produced at higher temperature. For the lower rank coal chars, the gasification rates were well correlated with the surface areas in a range around 0.4nm of pore radius.
