Hydrothermal Liquefaction of Palm Tree Waste Using CNT/Silica Nanocomposites: Effects of Process Conditions, Energy Recovery, and Compositional Analysis with Perspectives on SDG 7
J. Environ. Nanotechnol., Volume 14, No 4 (December 2025) pp. 219-229
Abstract
Palm trees are mainly cultivated in tropical and subtropical regions for fruit and date production, which in turn generates a substantial amount of agricultural residue. In this study, the sustainable processing of palm tree waste was explored via catalytic hydrothermal liquefaction (HTL) experiments. The HTL process was carried out with varying temperatures from 240 to 340 ºC, a reaction time of 60 min, a solvent-to-biomass ratio of 75 g/L to 200 g/L, and a catalyst load of 0.1 to 0.5 wt.% at a pressure of 20 bar. The recovered bio-oil was analyzed using proximate and ultimate analyses, GC–MS, and FTIR, while the biochar was characterized by SEM and FTIR. The maximum bio-oil yield of 28.9 wt.% was obtained at 300 ºC, a catalyst loading of 0.3 wt.%, and a biomass-to-solvent ratio of 175 g/L. The carbon content was 52.78 wt.% in the bio-oil and 78.49 wt.% in the biochar, with higher heating values (HHVs) of 30.86 MJ/kg and 25.58 MJ/kg, respectively. The bio-oil contained aliphatic and aromatic compounds, oxyacids, and hydrocarbons such as octadecane and hexadecane. The biochar exhibited high porosity and has the potential to serve as an effective adsorbent with broad environmental applicability. This study paves way for sustainable waste management, eco-friendly practices and green initiatives
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