“…The breakage of the weaker chemical bonds generates small molecules removed as gases (CO x , SO x , NO x , CH x, H 2 ), pyrolysis liquids (sometimes used as precursors of biofuels) and a solid residue enriched in carbon (char), but still having a scarce porosity. The use of hydrothermal carbonization (HTC) processes allows to low the carbonization temperature by contacting raw feedstock with pressurized water, saving energy and increasing the char yield, although high pressure reactors are needed (Yao et al, 2023). After carbonization, physical or chemical activation processes develop the porosity of the char.…”