Life cycle assessment of microalgae-derived biodiesel

Abstract Purpose Microalgae-derived biofuels are considered a low-carbon alternative to fossil fuels. Nevertheless, as with all biofuels, there is still uncertainty around their sustainability. Most life cycle assessments (LCA) of microalgae so far used lab-based, scaled-up lab experimental data or from the scientific literature. This article, provides evidence and analysis, undertaking an LCA using real-world industrial facility that uses combination photobioreactor fermenter systems. Methods The current well-to-wheel study aimed compare environmental impacts biodiesel production—under different energy regimes—and petroleum-derived diesel. functional unit was “combustion 1 MJ (Lower Heating Value) algal in internal combustion engine (as B100)”. considers construction facility, well those operation facility. foreground LCI collected one-hectare production pilot ReCiPe, IPCC AR5 (GWP100 GWP20) Global Temperature Potential (GTP) were implemented assess impacts. Results discussion assessment shows when infrastructure included, microalgae-derived not yet favourable over fuels on GWP100, this becomes worse shorter timescales. In terms climate change (GWP100), whilst (LHV) fossil-derived diesel would emit 8.84 × 10 −2 kg CO 2 eq, solar photovoltaic powered 1.48 −1 eq. To be equal perform better, productivity system needs improved most effective solution. results also showed electricity major sources impacts, yeast within fermenter. Moreover, it takes 0.99 direct per biofuel produced, similar fuel industry for Conclusions Using operational models, does unless can increased. Productivity improvements, through improvements strains designs, should priority ensure become sustainable feedstock. Electricity use reduced well, again, cultivation designs. system, high addressed, either co-locating ensuring specific lower Extracting lipids will effectively waste some high-value products, expected mixture unextracted lipids, polysaccharides fibre, proteins minerals. It shown harmonisations needed future studies facilities conclusively decide if they better other such feed products.