Morphology, physical and chemical properties of carbonaceous materials (CMs) synthesized by hydrothermal carbonization (HTC) of a technical lignin, HP-L-TM, derived from a bio-refinery waste-stream is reported. The technical lignin, HP-L-TM, was hydrothermally carbonized at four processing temperatures; 200, 250, 300 and 350 degrees C. The yield of derived CMs was highest at the lowest processing temperature (200 degrees C), and decreased with increasing temperature. L350, obtained at 350 degrees C was further chemically activated with KOH. SEM analysis showed that lignin exhibited agglomerated structures with some vesicles at elevated temperatures. Overall, major structural changes in the HP-L-TM lignin only occurred after 300 degrees C. Vibrational spectroscopy showed bands due to lignin functionalities disappeared at 350 degrees C. This was supported by deconvolution and peak analysis using NMR, which revealed the evolution of a more condensed structure characterized by aromatic C when temperature reached 350 degrees C. Unlike carbohydrates and other biomass types which can easily be hydrothermally carbonized at temperatures (160-220 degrees C), HP-L-TM lignin remains relatively unchanged up until 350 degrees C where significant aromatization occurs. 350 degrees C is therefore the desired temperature for the hydrothermal treatment of HP-L-TM lignin.