ANALYSIS OF MATERIAL COLLECTED ON PARTICLES EXPOSED TO VOLATILE MATTER OF BITUMINOUS COAL IN A FLUIDIZED-BED

The activity of fluidized bed particles towards the volatile matter of a bituminous coal was analysed by measurement of tar yield and the di rect measurement of CO2 concentration in the exhaust gas from the devo latilization of bituminous coal particles in a laboratory-scale fluidi zed bed reactor. In a third approach, thermogravimetric analysis (t.g. a.) of the fluidizing particles was performed, indicating that calcium -containing particles exhibited the largest weight loss. In a fourth a pproach, a mass spectrometer was connected to the t.g.a. instrument to identify the gases responsible for the weight loss. The results from the third and fourth approaches are presented in this paper. T.g.a. we ight loss profiles of calcium-containing solids under certain conditio ns were very complex. Mass spectrometric analysis of the effluent gase s from particles pre-exposed to the volatile matter of a bituminous co al in a fluidized bed showed that CaSO4 may decompose under reducing c onditions due to the presence of combustion intermediates such as CO a nd H-2, and the presence of oxygen may complete the sulfation reaction . (C) 1997 Elsevier Science Ltd.