During the ninth quarter, work continued on the measurements of coal particle temperatures from FT-IR emission spectra. Attention has been focused on the departures from black-body behavior which have been observed for several cases. Additional data have been obtained confirming that the high temperature departures from black-body behavior appear to be caused by soot formation. The short residence time departures still are not definitely confirmed. There is a wide discrepancy in reported rates for pyrolysis. Much of the problem appears to be due to heat transfer limitations which have not been properly accounted for. To address this problem a new experiment has been designed for rapid heat transfer. The experiments performed with a new reactor have yielded the highest rates ever measured in the 700 to 900/sup 0/C range. The results suggest that lower rates measured at these temperatures and comparable or lower rates measured at high temperatures were heat transfer limited. An interesting area of progress has resulted from a combined effort on our METC program and our GRI program. This work is aimed at examining the mechanisms of tar formation. A careful analysis of coal Field Ionization Mass Spectra (FIMS), specifically the regular arrangement of peaks, is providing some interesting results on coal structure. In a continuation of this work, several materials and a coal which had been perdeutero-methylated have been analyzed by the FIMS technique. The material series shows very high molecular weight tars for the high hydrogen exinites and very low molecular weight tars for fusinites, with the vitrinites in the middle. This variation in molecular weight is similar to what is observed for rank variations. The perdeutero-methylated coals are also quite interesting. The results suggest substantial deuterium scrambling, more fluidity, and a shift of the spectral features by 17, consistent with 1 hydroxyl group per molecule. 8 refs., 25 figs.