Conceptual Framework for the Production of Bioethanol and Byproducts from Microalgae Biomass

Abstract

Biofuel production from biomass is a promising alternative to fossil fuels. Biodiesel and bioethanol can be produced from lipids and carbohydrates of microalgae biomass, respectively. In this paper, a processing pathway from conceptual design process is proposed for liquid biofuels, to extract value-added products such as pigments and proteins from microalgae (Chlorella vulgaris). The process diagram consists of six main stages: vinasse anaerobic digestion, algae culture, biomass recovery, both bioethanol and biodiesel production. Simulations in ASPEN PLUS® software were performed in order to evaluate the mass and energy balances; heat integration using the Pinch Method was applied in order to minimize utilities consumption. 30 Ton/ h of vinasse were considered for treatment. Acid hydrolysis of cellulose to glucose was considered with a 96% performance and bioethanol production was carried out through a simultaneous saccharification and fermentation process, with a yield of 92.3% on the stage, 112 kg/h of ethanol, 28.5 kg/h of biodiesel, 126.5 kg/h of protein and 3 kg/h of glycerol were obtained by the process simulation.