Techno-economic and life-cycle assessment of an attached growth algal biorefinery.
This study examined the sustainability of generating renewable diesel via hydrothermal liquefaction (HTL) of biomass from a rotating algal biofilm reactor. Pilot-scale growth studies and laboratory-scale HTL experiments were used to validate an engineering system model. The engineering system model served as the foundation to evaluate the economic feasibility and environmental impact of the system at full scale. Techno-economic results indicate that biomass feedstock costs dominated the minimum fuel selling price (MFSP), with a base case of $104.31per gallon. Life-cycle assessment results show a base-case global warming potential (GWP) of 80gCO2-eMJ(-1) and net energy ratio (NER) of 1.65 based on a well-to-product system boundary. Optimization of the system reduces MFSP, GWP and NER to $11.90Gal(-1), -44gCO2-eMJ(-1), and 0.33, respectively. The systems-level impacts of integrating algae cultivation with wastewater treatment were found to significantly reduce environmental impact. Sensitivity analysis showed that algal productivity most significantly affected fuel selling price, emphasizing the importance of optimizing biomass productivity.
Biological Engineering, 4130 Old Main Hill, Utah State University, Logan, UT 84322, USA.
Jay
J
Barlow
Biological Engineering, 4130 Old Main Hill, Utah State University, Logan, UT 84322, USA.
Ronald C
RC
Sims
Mechanical & Aerospace Engineering, 4130 Old Main Hill, Logan, UT 84322-4130, USA. Electronic address: jason.quinn@colostate.edu.
Jason C
JC
Quinn
D018441:Biofilms / Q000254:growth & development; D056804:Biofuels; D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology / Q000191:economics; D003365:Costs and Cost Analysis; D008962:Models, Theoretical; D010865:Pilot Projects; D062065:Wastewater / Q000032:analysis
D056804:Biofuels; D062065:Wastewater
Algal biofilm; Greenhouse gas emissions; Hydrothermal liquefaction; Net energy ratio; Renewable fuel; Sustainability; Wastewater treatment