Abstract
In this study, a solvent extraction technique was investigated for the recovery of hydrocarbons from a concentrated slurry of Botryococcus braunii via thermal pretreatment. Efficient hydrocarbon recovery was achieved by preheating the slurry to temperatures below 100°C to achieve the separation of solids (solid-liquid separation), followed by the solvent extraction of hydrocarbons. This procedure did not require a highly energy consuming drying process. Parameters affecting the energy profit ratio and economy of hydrocarbon recovery, such as heating temperature, water content after solid-liquid separation, extraction time, and solvent-to-algae ratio, were examined with respect to hydrocarbon recovery efficiencies; it was found that heating the mixture to below 100 °C was sufficient for good hydrocarbon recoveries. It was also shown that solvent extraction carried out at room temperature required 2 h to reach saturation. At least 90% of the hydrocarbons could be recovered, even with low solvent-toalgae ratios, by adjusting the algae water content to around 85 wt%.
