Bio-crude oils production from wheat stem under subcritical water conditions and batch adsorption of post-hydrothermal liquefaction aqueous phase onto activated hydrochars

Hydrothermal liquefaction (HTL) is known to be a promising technology produce crude bio-oils as intermediate drop-in transport fuels. However, the co-production of wastewater (HTL-AP) and hydrochar residues (HCs) limits economic viability technical scalability. Hence, objective this work study effect catalysts NaOH,KOH,Na2CO3,K2CO3,H3PO4,FeCl3andFe2O3 in HTL reaction medium on characteristics derived from wheat stem under subcritical conditions at 350 °C for 15 min. Likewise, mentioned chemical agents were used enhance structural, morphological, surface properties HCs uptake organic adsorbates nutrients HTL-AP. A yield 30.85 wt% bio-oil, having highest HHV 34.36 MJ/kg, lowest 22.03 are achieved Na2CO3-catalyzed HTL. In contrast, acidic Fe-based revealed lesser bio-oil because low pH, which promotes dehydration polymerization reactions. Reduced Na, K, Fe, S contents found H3PO4, FeCl3, Fe2O3-catalyzed biocrudes. This result supports hypothesis situ demetallation during due their adsorption onto mesoporous hydrochars with Dp = 13.77–33.58 nm. The removal efficiency levels COD, TOC, phenols, total N, P, dissolved K 66.67–92.77 %, 62.58–91.84 65.59–99.91 37.63–80.80 96.67–99.90 45.57–92.36 respectively after HTAL-AP treatement. results demonstrate new insights directions use activated low-cost adsorbent HTL-AP remediation purposes.