Selection of harvesting technology for Botryococcus braunii as feedstock of bio-crude oil production

The continuous increase in energy consumption of fossil fuels has led to the urgency of research and development in the field of renewable energy for the future. Meanwhile, microalgae such as Botryococcus braunii are among the renewable energy alternatives and a third-generation source of bio-crude oil, producing more biomass compared to others. However, the challenges that are usually encountered in the selection of an effective approach for microalgae harvesting are the small size of cells (3-30 µm) and the similarity between their densities and growth media. Therefore, this research aims to determine the appropriate microalgae harvesting technology for bio-crude oil production using the Analytical Hierarchy Process (AHP). Several potential harvesting technologies that have been used include centrifugation, filtration, inorganic and organic flocculation, bioflocculation, electrocoagulation, and flocculation-sedimentation. The results showed that the parameters considered include energy need (0.339), cost (0.214), risk of contamination (0.098), efficiency (0.133), technology availability (0.066), microalgae strain flexibility (0.079), and production time (0.071). Subsequently, the pairwise comparison of seven alternatives and criteria for each harvesting technology are compared. Based on the results, flocculation-sedimentation with a weight of 0.202 is the best alternative that can be recommended as a microalgae harvesting technology.