Oil extraction from algae: A comparative approach.

Area of Science:

• * Biotechnology and Bioengineering
• * Renewable Energy Sources
• * Algal Biomass Utilization

Background:

• * Microalgae, such as Chlorella vulgaris, are a promising source of lipids for biofuel production.
• * Efficient and scalable lipid extraction methods are crucial for the economic viability of algal biofuels.
• * Optimizing solvent systems and extraction techniques is key to maximizing lipid yield.

Purpose of the Study:

• * To compare the efficacy of soxhlet, Bligh & Dyer (B&D), and ultrasonic-assisted B&D methods for lipid extraction from Chlorella vulgaris.
• * To optimize solvent composition and ratios using response surface methodology (RSM) for enhanced lipid recovery.
• * To evaluate the suitability of the extracted lipids for biodiesel production.

Main Methods:

• * Lipid extraction was performed using soxhlet, B&D, and ultrasonic-assisted B&D techniques.
• * Solvent systems (e.g., hexane-methanol, chloroform-methanol, chloroform-methanol-water) and their proportions were systematically varied.
• * Response surface methodology (RSM) was employed to optimize solvent polarity and water content for maximum lipid yield.

Main Results:

• * The Bligh & Dyer method using chloroform-methanol-water (50%-35%-15%) achieved the highest lipid extraction yield of 24%.
• * Soxhlet extraction yielded a maximum of 19.87% lipid using chloroform-methanol (54%-46%).
• * Ultrasonication and osmotic shock enhanced lipid yield by approximately 3.52%, increasing the total yield to nearly 15% in some cases.

Conclusions:

• * The Bligh & Dyer method, particularly with a chloroform-methanol-water system, is highly effective for extracting lipids from Chlorella vulgaris.
• * Optimized extraction parameters significantly improve lipid yield, making it suitable for biodiesel applications.
• * The study demonstrates the potential of Chlorella vulgaris as a feedstock for sustainable biodiesel production.