title: Pilot-scale data provide enhanced estimates of the life cycle energy and emissions profile of algae biofuels produced via hydrothermal liquefaction.
abstract: Life cycle assessment (LCA) has been used widely to estimate the environmental implications of deploying algae-to-energy systems even though no full-scale facilities have yet to be built. Here, data from a pilot-scale facility using hydrothermal liquefaction (HTL) is used to estimate the life cycle profiles at full scale. Three scenarios (lab-, pilot-, and full-scale) were defined to understand how development in the industry could impact its life cycle burdens. HTL-derived algae fuels were found to have lower greenhouse gas (GHG) emissions than petroleum fuels. Algae-derived gasoline had significantly lower GHG emissions than corn ethanol. Most algae-based fuels have an energy return on investment between 1 and 3, which is lower than petroleum biofuels. Sensitivity analyses reveal several areas in which improvements by algae bioenergy companies (e.g., biocrude yields, nutrient recycle) and by supporting industries (e.g., CO2 supply chains) could reduce the burdens of the industry.
authors.affiliation: Civil and Environmental Engineering, 351 McCormick Road, Thornton Hall, University of Virginia, Charlottesville, VA 22904, United States.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liu
authors.forename: Benjamin
authors.initials: B
authors.lastname: Saydah
authors.forename: Pragnya
authors.initials: P
authors.lastname: Eranki
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Colosi
authors.forename: B
authors.initials: B
authors.lastname: Greg Mitchell
authors.forename: James
authors.initials: J
authors.lastname: Rhodes
authors.forename: Andres F
authors.initials: AF
authors.lastname: Clarens
mesh_terms: D000397:Air Pollution / Q000032:analysis*; D056804:Biofuels / Q000032:analysis*; D001709:Biotechnology / Q000379:methods*; D056890:Eukaryota / Q000378:metabolism*; D005742:Gasoline / Q000032:analysis; D017752:Greenhouse Effect; D008962:Models, Theoretical; D010865:Pilot Projects; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D056804:Biofuels; D005742:Gasoline; D014867:Water
keywords: Algae; Biofuels; Energy return on investment; Hydrothermal liquefaction; Life cycle assessment