Chapter 17 Process integration opportunities applied to microalgae biofuels production

Third-generation biofuels derived from microalgae are considered a promising candidate to reduce greenhouse gas emissions, especially applicable for the transportation sector, as the high lipid and carbohydrate content of microalgae results in high yields of liquid fuels compatible with current engine technologies. Microalgae have a number of advantages over conventional biomass sources including rapid growth (full cycles within days compared to weeks), use of CO2 as a carbon source, and low nutrient requirements (can be from contaminated wastes, wastewater, or seawater). However, biofuels derived from microalgae have a few challenges due to the very high water content of the feedstock, thereby increasing drying and separation costs, and high contents of nitrogen and oxygen compounds, which result in lower quality and acidic fuels, requiring upgrading processes. To address these challenges, process intensification and integration should be focused towards maximizing nutrient recovery, minimizing the needs for bio-oil upgrading and drying of the microalgae after harvesting. This chapter will discuss current state-of-the-art technologies for biofuel production in the context of microalgae biofuel production, current challenges hindering commercialization, and how process intensification technologies can be used and integrated to make microalgae-derived biofuels more commercially viable.