During the fifteenth quarter, the particle-temperature and Functional Group Models were used to simulate results of pyrolysis of Illinois No. 6 coal in the heated tube reactor with good results. Pyrolysis studies were done with North Dakota lignite and Montana Rosebud coals at 30 K/min in a combined TGA/EGA instrument developed at AFR. We optimized the set of kinetic rates and coal composition parameters to fit both the low heating rate data from this system (0.5 K/s) and high heating data from the heated tube reactor (20,000 K/s), with reasonable success. The procedures for char reactivity, active site density, and surface area measurements were established and a set of chars was selected. Chars were analyzed for sulfur forms from pyrolysis of Kentucky No. 9 coal in the entrained flow reactor at 1100/sup 0/C and 1600/sup 0/C. A test plan was completed for pyrolysis experiments in the high pressure reactor. Data collection was begun with North Dakota lignite, which shows only modest pressure effects. Work proceeded on the application of the FT-IR emission/transmission spectroscopy in two areas: (1) the measurement of the spectral emittance for coal and char and (2) the measurement of temperature in the Entrained Flow Reactor (EFR). We have begun work on integrating a version of the hydrocarbon cracking model into the Functional Group (FG) Model for coal pyrolysis. This will allow us to make better predictions of olefin and acetylene yields and will add the ability to predict soot formation. We have also begun work in integrating the DRC (depolymerization, repolymerization, crosslinking) model into the FG model. This will allow prediction of the amount and molecular weight distribution of tar, along with pressure effects on tar yields. 13 refs., 21 figs.