Hydrothermal liquefaction of Fucus vesiculosus algae catalyzed by Hβ zeolite catalyst for Biocrude oil production

Abstract

Low lipid content brown algae (Fucus vesiculosus) are considered an efficient biocrude oil source for their higher productivity rate, adaptation, and ease of cultivation. The hydrothermal liquefaction process can directly utilize algal biomass in the wet state. Hβ zeolite catalyst activity was tested for the hydrothermal liquefaction process of F. vesiculosus algal biomass. Maximum biocrude oil yield (27.6%) from the F. vesiculosus algae feedstock was obtained using catalyst amount of 15 wt%, residence time of 20 min, and temperature of 300 °C. The higher heating value (HHV) of the biocrude oil product was found to be 38.47 kJ/kg. Chemical compounds in the biocrude oil and aqueous phase products were detected using Gas Chromatography-Mass Spectroscopy (GC–MS) showing the main compounds to be ketones, and nitrogen-containing and heterocyclic compounds in biocrude oil, while oxygenated compounds prevail in the aqueous phase. Low amounts of amines and amides due to low protein content and of esters and hydrocarbons because of low lipids content were found in the F. vesiculosus algae feedstock. Biocrude oil energy efficiency was 45.68% compared to the biochar energy efficiency of 16.54%.