Catalytic pyrolysis of natural algae from water blooms over nickel phosphide for high quality bio-oil production

Abstract

A large abundance of environmentally harmful biomass waste is generated by water blooms. In order to provide an applicable solution for the relief of the environmental pressure, natural algae of Taihu Lake water blooms (CTL), mainly cyanobacteria, were catalytically pyrolyzed over silica-supported nickel phosphide to produce bio-oil. The properties of the bio-oil, such as chemical composition, elemental composition, and higher heating value (HHV), were examined. The composition of the gas product was also detected. The results suggest that catalytic pyrolysis could effectively convert the algae to a high quality bio-oil, in which the oxygen content was considerably reduced from 41.7 wt% in the algae to 8.0 wt% in the bio-oil. Long-chained alkanes became the primary component (59.4%). The HHV of the bio-oil obtained from catalytic pyrolysis was 37.2 MJ kg⁻¹. The results indicate that it is possible to achieve high-grade renewable transportation fuels via catalytic pyrolysis of environmentally harmful CTL, and nickel phosphide is an applicable and effective catalyst.