Life cycle assessment on microalgal biodiesel production using a hybrid cultivation system.
A life cycle assessment (LCA) was performed on a putative biodiesel production plant in which the freshwater alga Chlorella vulgaris, was grown using an existing system similar to a published commercial-scale hybrid cultivation. The hybrid system couples airlift tubular photobioreactors with raceway ponds in a two-stage process for high biomass growth and lipid accumulation. The results show that microalgal biodiesel production would have a significantly lower environmental impact than fossil-derived diesel. Based on the functional unit of 1 ton of biodiesel produced, the hybrid cultivation system and hypothetical downstream process (base case) would have 42% and 38% savings in global warming potential (GWP) and fossil-energy requirements (FER) when compared to fossil-derived diesel, respectively. Sensitivity analysis was performed to identify the most influential process parameters on the LCA results. The maximum reduction in GWP and FER was observed under mixotrophic growth conditions with savings of 76% and 75% when compared to conventional diesel, respectively.
Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom. Electronic address: voa22@cam.ac.uk.
Victoria O
VO
Adesanya
Department of Hydraulic, Maritime and Environmental Engineering, Universitat Politècnica de Catalunya, BarcelonaTech, E-08034 Barcelona, Spain.
Erasmo
E
Cadena
Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom.
Stuart A
SA
Scott
Department of Plant Sciences, University of Cambridge, Downing Site, Cambridge CB2 3EA, United Kingdom.
Alison G
AG
Smith
D056804:Biofuels; D018533:Biomass; D058086:Microalgae / Q000254:growth & development / Q000378:metabolism*; D058433:Photobioreactors
D056804:Biofuels
Biodiesel; Environmental impact; Hybrid cultivation system; Life cycle assessment; Microalgae