Hydrothermal liquefaction and pyrolysis of Amphiroa fragilissima biomass: Comparative study on oxygen content and storage stability parameters of bio-oil

Abstract

Amphiroa fragilissima was converted to bio-oil through two pathways: hydrothermal liquefaction (HTL) and pyrolysis. Biomass (10 g) was processed separately through HTL (220–340 °C) and pyrolysis (340–520 °C) under nitrogen environment (5 MPa) for reaction time of 60 min. The bio-oils were analyzed through Gas Chromatography Mass Spectrophotometry (GCMS). The maximum bio-oil yield was HTL (28.9 wt%) and pyrolysis (33.5 wt%) at a temperature of 320 °C and 460 °C for time of 60 min. The storage stability of both bio-oils was evaluated with time (0–60 days), temperature (5, 15, 25 and 35 °C) and storage container (glass, stainless steel, fiber- reinforced fiber, plastic). Viscosity of HTL and pyrolysis bio-oils increased to 2.1 and 1.5 times at 35 °C. The HHV value increased by 1% and 1.5% for HTL and pyrolysis bio-oils stored in stainless steel container at 35 °C for time 60 days. This study targets industries since they store bio-fuels in large tanks for longer duration.