Gasification kinetics of an Indonesian sub-bituminous coal-char with CO 2 at elevated pressure

Abstract

Gasification kinetics of an Indonesian sub-bituminous coal-char with CO 2 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 CO 2 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= kP gas n ) was modified to be R= kP gas n P total m to describe the gasification rate where the total system pressure changes. The gasification reaction rate of char–CO 2 at high temperature and elevated pressure may be expressed as dX/ dt=(174.1) exp(−71.5/ RT)(P CO 2 ) 0.40(P total ) 0.65(1−X) 2/3.