Eight types of biomass waste samples, microcrystalline cellulose, hemicellulose, and lignin were subjected to a degradative extraction method that treats carbonaceous resources in a non-hydrogen donor at around 350 degrees C. The treated products were separated at 350 degrees C to recover the extract and residue (the latter was termed Residue). The extract was further separated into two fractions: a fraction that precipitates as a solid (termed Deposit(s)) and the soluble fraction (termed Soluble(s)) at room temperature. The carbon-based yields of the three fractions obtained from the biomass wastes were 36.8-71.6% Solubles, 4.4-10.6% Deposits, and 15.1-27.5% Residues. The remaining carbon was converted to CO2, CO, and a small amount of hydrocarbons that could not be separated from the solvent. Most of the ash was concentrated in the Residues, whereas the Solubles were almost completely free from ash. Surprisingly, the chemical and physical properties of the Solubles produced from the eight biomass waste samples were highly similar. The Solubles from the various biomasses had elemental compositions in the range of C = 81.0-83.3 wt %, H = 6.1-7.3 wt %, and 0 = 7.3-11.1 wt %. The Solubles comprised uniform low-molecular-weight compounds with a peak molecular weight at around 300. The Solubles melted completely below 90 degrees C, and 60-70% of the Solubles were devolatilized below 400 degrees C. The Solubles, which constituted the largest yield fraction and have unique properties, have potential utility for various purposes.