In this work, we aim to evaluate the potential of hydrothermal carbonization (also known as wet pyrolysis) as a pretreatment, by evaluating the changes induced in the raw material (cellulose) under varying experimental conditions. Hydrocarbonization processes were performed under different temperature, time and biomass/water ratios following a response surface methodology. The hydrochars obtained were characterized in terms of proximate analysis, behavior towards pyrolysis and combustion, heating value and surface textural and chemical features. The presence of typical hydrocarbonization reactions (dehydration, hydrolysis, decarboxylation, decarbonylation, recondensation, etc.) was only possible if a limit temperature (200°C) was used. Under these conditions, proximate analyses changed, the surface chemistry was modified, and the formation of a second lignite-type solid fraction was observed.
Part of the book: Analytical Pyrolysis