The goal of this program was to develop the techniques to characterize coal and use this characterization to predict the coal's behavior in a gasifier. To accomplish this goal, detailed data on devolatilization product yields and compositons, were obtained with measured particle temperature for a variety of coals under a wide variety of conditions (temperatures: 20/sup 0/C to 1650/sup 0/C, pressures: vacuum to 200 psi, heating rates: 3/sup 0/C/min to 20,000/sup 0/C/sec). Several unique reactors were developed and employed to provide these conditions. New diagnostic techniques were developed for in-situ measurements and characterization of products including a new method employing Fourier Transform Infrared (FT-IR) spectroscopy for characterizing the temperature, composition, emissivity and size of particulates under reaction conditions. Separation of chemical kinetic rates and mass transfer rates for coal pyrolysis was accomplished by employing the new FT-IR particle temperature measurement technique. In addition, Field Ionization Mass Spectroscopy and FT-IR were used to determine molecular weight distribution and functional group compositions of tars. Theoretical models were developed and implemented as computer codes to describe the observations on coal pyrolysis. A previously developed Functional Group (FG) model was extended and improved. It has been successful in describing the primary pyrolysis products. A Depolymerization, Vaporization, Crosslinking (DVC) model developed for polymers used to simulate coal structure, under GRI sponsorship, was applied to interpret the results for coal. This model has been successful in predicting the observed trends for tar yield and molecular weight distribution. The program has succeeded in providing good predictive models for many of the primary events occurring during coal pyrolysis. 211 refs., 107 figs., 12 tabs.