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 reactor. The effects of gasification temperature (900–1400°C), 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 determined. It was found that the gasification rate was dependent on the total system pressure with the same partial pressure and temperature. The nth-order rate equation (R=kPgasn) was modified to be R=kPgasnPtotalm to describe the gasification rate where the total system pressure changes. The gasification reaction rate of char–CO2 at high temperature and elevated pressure may be expressed as dX/dt=(174.1) exp(−71.5/RT)(PCO2)0.40(Ptotal)0.65(1−X)2/3.