After liquefaction, the rice husk was converted into a carbonaceous residue referred to as hydrochar. As shown in Table 2, the elemental composition of SR changed significantly as a result of carbonization. Due to the dehydration and decarboxylation reactions, the solid mass decreased and energy densification occurred. The energy densification factor defined as HHVSR/HHVfeedstock reached up to about 1.3. This carbonized SR (hydrochar) has enormous potential for environmental- and energy-related applications such as an adsorbent for harmful pollutants, feedstock for carbon
fuel cells, and a soil amendment (similar to char from pyrolysis/ gasification) [29].