Economic and life cycle assessment of biomass liquefaction technology

Abstract

Microalgae are promising feedstock for biofuel production due to their high growth rate and lipid content, compared with other biomass. This study investigated the techno-economic and life cycle environmental impacts of a two-stage microalgae liquefaction plant with an annual design capacity of 0.5 million gallons of bio-crude oil. The total capital investment and annual operating cost were estimated as $113 million and $13 million respectively, with a minimum selling price of $49.80/gal ($44.30/gge) and the net greenhouse gas emission was evaluated as 15.55 kgCO2eq/gal (114.63 gCO2eq/MJ). The life cycle impacts of biochar/bio-oil production from pyrolysis technologies of woody biomass were also investigated to compare with algae liquefaction technology. The study suggests that bio crude oil production from algae is not economically competitive compared with fossil based crude oil. Further research is required to enhance algae productivity and bio crude oil yield.