Kinetics of sodium sulfate reduction in the solid state by carbon monoxide

Abstract

The kinetics of Na 2SO 4 reduction in the solid state by CO is studied in a thermogravimetric system below 800°C. The reduction is autocatalytic and can be described by an initiation, acceleration and deceleration period. The initiation reaction is between CO and Na 2SO 4. Without CO 2 present, the deceleration period is described by solid-solid phase boundary reaction controlled kinetics. With CO 2, the kinetics are product layer diffusion controlled. The reduction rate is strongly retarded by CO 2. The reduction is catalyzed by TiO 2 and Fe 3O 4. In the presence TiO 2, the reduction kinetics are controlled by ash layer diffusion.