The goal of this project was to obtain improved quantitative understanding of certain features of coal devolatilization of significant interest for coal gasification technology, for basic coal science, and for coal utilization in general. The work features systematic experimental and related mathematical modeling studies of reactions of newly formed coal pyrolysis tars within pyrolyzing coal particles and of how coal type affects the rapid devolatilization behavior of coal. Extensive new data bases were provided on these phenomena and mathematical models and/or correlations were developed for: (1) intra-particle transport and secondary reactions for coal pyrolysis tars; (2) effects of coal type and total pressure on total pyrolysis tar yield; (3) effects of heating rate on global coal devolatilization rates; and (4) effects of coal type on global rates of weight loss in rapid devolatilization.