Gasification kinetics of an Indonesian sub-bituminous coal-char with CO2 at elevated pressure

Gasification kinetics of an Indonesian sub-bituminous coal-char with CO2 at elevated pressure was investigated with a pressurised drop tube furnace re actor. The effects of gasification temperature (900-1400 degreesC), partial pressure of carbon dioxide (0.1-0.5 MPa), and total system pressure (0.5, 0.7, 1.0, 1.5 MPa) on gasification rate of the coal-char with CO2 were dete rmined. It was found that the gasification rate was dependent on the total system pressure with the same partial pressure and temperature. The nth-ord er rate equation (R = kP(gas)(n)) was modified to be R = kP(gas)(n),P-total (m) to describe the gasification rate where the total system pressure chang es. The gasification reaction rate of char-CO2 at high temperature and elev ated pressure may be expressed as dX/dt = (174.1)exp(-71.5/RT)(P-CO2)(0.40) (P-total)(0.65)(1 - X)(2/3). (C) 2001 Published by Elsevier Science Ltd.