Extraction Solvents Composition Effect In Biodiesel Production From Microalgae Consortium Botryococcus Braunii And Dunaliella Sp.

Abstract

Indonesia has entered an energy emergency phase, proven that Indonesia is no longer a surplus oil producer due to the productivity of the wells decrease over the years and the pattern of people's consumption of fossil fuels has been exceeding the production capacity. Therefore, we need the right solution to overcome this problem, which is developing biodiesel as renewable energy based on microalgae oil. The microalgae used in this research is the consortium of microalgae Botryococcus braunii and Dunaliella sp. Microalgae were cultivated and harvested through the dewatering process with 1 g naoh/1 L water concentration. Water contents of cultivated Botryococcus braunii are 60.2505% while Dunaliella sp. Is 64.5002%. The oil from microalgae is obtained by extracted dry microalgae through the soxhlet extraction (leaching) method with mixed solvent n-hexane and ethanol as the co-solvent using a variety of solvent ratio 2:1 and 3:1. Pure microalgae consortium oil separated from the solvent using the distillation process then analyzed with GC-FID. The analysis result is trans-linoleic acid is the most dominant fatty acid contained in this oil. Transesterification process with cao (1.5% of oil weight) as a catalyst. The results obtained from this study are the oil yield 72% extracted with a solvent mixture of n-hexane and ethanol 2:1 and 60.4% for 3:1. The biodiesel synthesis resulted in the amount of yield obtained from the solvent ratio 2:1 extraction is 94.3%, while with solvent ratio 3:1 is 79.2%. The quality of both biodiesels has met the requirements of SNI 7182:2015 and ASTM D7467, except the density of biodiesel with extraction solvent composition 3:1 which is below the standard. Therefore, the best biodiesel quality is obtained from microalgae consortium’s oil with the composition of extraction solvent 2:1.