Photo‐catalytic reforming of aqueous phase derived from hydrothermal liquefaction of Nostoc ellipsosporum for bio‐hydrogen production

Abstract

In this study, green fuel (hydrogen energy) was produced from the aqueous phase obtained from the hydrothermally liquefied Nostoc ellipsosporum biomass via photo-catalytic reforming. Initially, algae were cultivated in municipal wastewater and fog medium (80:20) in photo bio-reactor for biomass production. Later the algae biomass was liquefied under varying temperature of 220 C to 320 C at 5Mpa for 60 min. From the results, it was seen that the maximum bio-oil yield was 31 wt% for biomass to solvent ratio of 0.05 g/mL at 300 C. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis of bio-oil showed the presence of hydrocarbons like octadecane, heptadecane, etc. Aqueous phase comprised of hydrogen generating low molecular weight compounds. Photo-catalytic reforming process with 0.1 g of TiO 2 catalyst at time of 2 h resulted in hydrogen yield of 27 wt%. Catalyst reusability study resulted in cumulative hydrogen yield of 76 wt% from five consecutive cycles.