To obtain kinetic parameters on PAH formation relevant to solid fuels combustion, pyrolysis experiments have been conducted with catechol, a model fuel representing entities in coal and biomass. Catechol pyrolysis experiments were performed in a tubular-flow reactor at temperatures of 500-1000 degreesC and at a residence time of 0.4 s. PAH products were identified and quantified by high-pressure liquid chromatography with ultraviolet-visible diode-array detection and by gas chromatography with flame ionization and mass spectrometric detection, A pseudo-unimolecular reaction kinetic model was used to model the experimental yield/temperature data of 15 individual aromatics and of combinations of PAH grouped by structural class and ring-number. The modeling of the individual species' yields showed that the pseudo-unimolecular model agreed very well with the experimental data. E-a values ranged from 50 to 110 kcal mol(-1), generally increasing as the size of the aromatic product increased from one to five aromatic rings. The pseudo-unimolecular model also performed well in modeling the experimental yields of PAH grouped by structural class and ring number. The global kinetic analysis results for PAH grouped by ring number revealed that E-a values increased in the following order: 2-ring < 3-ring < 4-ring < 5-ring < 6-ring. Their yields followed the reverse order: 2-ring > 3-ring > 4-ring > 5-ring > 6-ring. These trends of increasing E-a and decreasing yield, as ring number is increased, are consistent with a mechanism for PAH growth involving successive ring buildup reactions.