Design and optimization of lipids extraction process based on supercritical CO2 using Dunaliella Tertiolecta microalga for biodiesel production

Extraction of oil with supercritical CO2 solution to produce biofuels from Dunaliella tertiolecta microalga was investigated. 8 treatments during two light periods of light and dark with different shocks of acidity, salinity and nutrients were studied individually and in pairs. As the amount of Dunaliella Tertiolecta microalga produced biomass increased (more than 2.5 g L-1 after 12 day), CO2 consumption rate increased (629.97 +/- 34.62 mgL(-1) d(-1)). A more diverse fatty acid content was observed in the present study in Dunaliella Tertiolecta microalga, include: palmitic acid (C16:0), stearic acid (C18:0), erucic acid (C22:1n9), nervonic acid (C24:1n9), docosahexaenoic acid (C22:6n3) and eicosadienoic acid (C20:3n3). The measured iodine value (IV) and saponification value (SV) showed no significant differences between the experimental samples (P < 0.05). The cetane number and degree of saturation in the biofuel produced by microalga were high, therefore, the biofuel was of high quality. The amount of oil extracted in the control and optimal treatments showed that increasing the pressure has a positive effect on the extraction and the best temperature was 40 degrees C with a pressure of 370 bar. (C) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

This study investigated the extraction of oil from Dunaliella tertiolecta microalga using supercritical CO2 solution to produce biofuels. The results showed that the biomass production of Dunaliella Tertiolecta microalga and the consumption rate of CO2 were positively correlated. The biofuel produced had a diverse fatty acid content and high quality. Increasing the pressure during the extraction process had a positive effect, and the optimal temperature for extraction was 40 degrees Celsius.