Exploring microalgae species for integrated bioenergy Production: A Multi-Fuel cascade valorisation approach

Abstract

The present study aims to evaluate the cascade valorisation of microalgae for bioenergy production after defining the most promising species between Aurantiochytrium sp., Scenedesmus obliquus, Nannochloropsis oceanica, and Nannochloropsis sp.. For selection, biodiesel (after hexane lipid extraction coupled with cell-disruption methods) and bioethanol (after acid hydrolysis) were produced from raw biomass. Aurantiochytrium sp. achieved the highest oil and FAME contents (21 ± 1 wt% and 58.9 ± 0.6 wt%, respectively), as well as the highest bioethanol concentration (5.4 ± 0.3 g/L). The integrated production of biodiesel, bioethanol and biogas led to a decrease in bioethanol and biogas production efficiency compared to raw biomass (around 30 % and 60 %, respectively). However, it allows multiple product outputs, potentially improving economic and environmental outcomes. The current study highlights the potential of using microalgae species such as Aurantiochytrium sp. for bioenergy production, in a zero-waste approach.