Yields of gases, water, water-soluble organics, and water-insoluble char are reported for hydrothermal pretreatment of paper dunnage at several conditions. Chars are characterized in terms of chemical composition, slurry-forming properties, and pyrolysis properties. Pyrolysis yields, relative reactivities, and kinetic parameters for evolution of volatile organic components from isolated chars were determined by Pyromat micropyrolysis. For both the water-insoluble chars and solvent-extracted chars, pyrolysate yields decreased with increasing pyrolysis severity, and the temperature of maximum evolution rate for a constant heating rate (T-max) increased. The extracted residues have less low-temperature evolution and narrower evolution profiles overall. Kinetic analysis used the T-max shift (approximate) and discrete distribution methods. Except for one sample, all of the extracted chars have similar kinetic parameters, i.e., activation energies in the range of 54-56 kcal/mol and frequency factors in the range of 10(15) s(-1). The exception was from the most severe pretreatment conditions and exhibited much higher activation energies. FTIR analyses of the extracted chars and isolated extracts indicate the structures of the extracted chars are very similar, except for the most severe pretreatment sample. The results are used to assess the suitability and limitations of a parallel reaction model for pyrolysis of paper, especially for modelling hydrothermal pretreatment of gasifier slurry feeds.