Microwave-Assisted Pretreatment Coupled with Maceration: An Innovative Pathway for Maximized Lipid Recovery from Chlorella vulgaris

Department of Chemical Engineering, Politeknik Negeri Bandung, Indonesia

^* Corresponding author: lidya.elizabeth@polban.ac.id

Abstract

Microalgae represent a promising renewable resource with significant potential for applications across various sectors, including biodiesel production, food, and pharmaceuticals. Chlorella vulgaris is recognized for its high lipid content, particularly rich in fatty acids. However, this species' rigid cell wall structure presents a considerable challenge for efficient lipid extraction. This work investigates the integration of microwave-assisted pretreatment and maceration for high-yield lipid recovery from Chlorella vulgaris. The experimental methodology was conducted in two stages. In the first stage, microalgae samples were subjected to microwave pretreatment at 360 watt microwave power and pretreatment duration between 0.75 and 8 minutes. In the second stage, the pretreated biomass underwent maceration at temperatures ranging from 30°C to 50°C, with extraction durations from 30 to 180 minutes. The results demonstrated that the optimal lipid yield of 75.96% (w/w dry weight) was obtained with an 8-minute microwave pretreatment followed by maceration at 30°C for 105 minutes. The integration of prolonged microwave pretreatment effectively disrupted the robust cell wall structure, facilitating solvent penetration during the maceration stage. Conducting the maceration process at low temperature minimized the lipid degradation risk, thus enhancing extraction efficiency.