Ultrasound-Assisted Lipid Extraction from Chlorella sp.: Taguchi Design and Life Cycle Assessment

Area of Science:

• Biotechnology
• Chemical Engineering
• Renewable Energy

Background:

• Microalgae like Chlorella sp. are a sustainable source for biofuels.
• Traditional methods for extracting essential oils (EOs) from microalgae can be inefficient.
• Optimizing extraction parameters is crucial for maximizing yield and economic viability.

Purpose of the Study:

• To enhance essential oil (EO) extraction from Chlorella sp. using ultrasound-assisted extraction (UAE).
• To identify optimal extraction parameters via the Taguchi method.
• To evaluate the fatty acid profile and assess the environmental impact of the UAE process for biodiesel production.

Main Methods:

• Utilized the Taguchi method to optimize UAE parameters: ultrasonic amplitude, reaction duration, hexane/ethanol ratio, and temperature.
• Performed experimental validation of the optimized parameters.
• Conducted fatty acid profile analysis and life cycle assessment (LCA) using CML and TRACI methods.

Main Results:

• Optimal EO yield of 18.8% ± 0.2% achieved at 80% ultrasonic amplitude, 15 min, 3:1 hexane/ethanol ratio, and 40°C.
• Extracted EO rich in long-chain fatty acids (C14-C20), including Palmitic, Heptadecanoic, Oleic, and Linoleic acids.
• Identified lipid extraction as the primary contributor to global warming and ecotoxicity in the LCA.

Conclusions:

• UAE is an effective and efficient method for extracting EO from Chlorella sp.
• The extracted EO has potential for biodiesel production, though oxidative stability needs consideration.
• UAE presents a promising and ecologically sound alternative to conventional methods for microalgal biodiesel production.