Reviews in Chemical Engineering, vol.15, no.4, pp.245-264, 1999 (SCI-Expanded)
This study involves thermochemical decomposition of desulphogypsum (DG) in the presence of oil shale (OS) in a bench scale fluidized bed reactor (FBR). Experiments were carried out thermochemically under isothermal conditions in a batchwise manner at different added weight fractions of OS varying from 0.1 to 0.3 (w/w). The temperature range considered was in the range of 1173-1273 K. The gas phase obtained from thermochemical decomposition of the sample was monitored by gas analysers (MSI 5600/Germany and MIR 9000/France) and all process data was recorded on-line at regular intervals by a data acquisition system specifically developed for this purpose. Concentration-time data was evaluated for each run to obtain conversion-time curves. Overall reaction rate was found to be kinetics controlled in compliance with the Avrami equation which represented the observed data reasonably well. The rate constant was found to have an activation energy of 201 kJ/mol for the 0.30 weight fraction of OS in the feedstock. Increased operating temperature at a pre-set feed ratio of OS to DG increased SO2 and CO concentration. This indicated the possibility that the reducing atmosphere created by the presence of OS would be continuing at still higher temperatures.