Improvement in microalgae lipid extraction using a sonication-assisted method

Investigation of the effects of microalgal cell concentration and electroporation, microwave and ultrasonication on lipid extraction efficiency

“…The process involves the use of a solvent that matches the polarity of the target compound, non-polar lipids [5]. The solvent must also make contact with the lipids inside of the cell [6], which generally requires a second polar solvent to break the cell wall and membrane. Several studies [7e12] employed the Bligh and Dyer method [13], which uses chloroform, methanol, and water as co-solvents for extracting and purifying lipids.…”

Continuous and pulse sonication effects on transesterification of used vegetable oil

“…The cavitational energy is further converted into chemical, physical, and biological effects depending on the application and reaction environment. In biodiesel process applications, chemical, and physical (thermal) effects are evidenced by many researchers through a significant rise in the reaction temperature, reaction yields, intense mixing [8,[14][15][16][17][18] and in some applications through destruction of cell membranes for oil extraction such as in algae biodiesel production which can be considered a biological effect [19][20][21][22][23][24]. Lin et al [25] attributed three important phenomena to the effect of ultrasonic irradiation: (1) rapid movement of fluids caused by a variation of sonic pressure causes solvent compression and rarefaction; (2) cavitation; and (3) microstreaming where large amount of vibrational energy is confined in small volumes of reaction medium with less heating [25,26].…”

A review on the extraction of lipid from microalgae for biodiesel production

“…The non-polar solvents disrupt the hydrophobic interactions between non-polar and neutral lipids available in the algae biomass. The solvents used for extracting lipid from microalgae biomass are n-hexane, ethanol, 1-butanol, DBU (1,8-diazabicyclo- [5.4.0]-undec-7-ene), dimethyl ether, and mixtures of chloroform/methanol, n-hexane/ethanol, n-hexane isopropanol, n-hexane/2-propanol, methanol/1-ethyl-3-methyl imidazolium methyl sulfate, DBU/ethanol, DBU/octanol, methylene chloride/methanol, dichloroethane/methanol, dichloroethane/ethanol, and acetone/dichloromethane [18]. Among these, chloroform/methanol (1/2 v/v) is the most widely used organic solvent system extracting lipid from biomass and animal tissues, as the extraction time is reduced with increased yield.…”

“…The thick cell walls of microalgae blocks the release of intralipids present inside and the use of methods like solvent extraction and mechanical press, yields less lipid [18]. The principle behind ultrasound assisted extraction method is that the intense sonication of liquid generates sound waves that propagate into the liquid media and results in alternate high-pressure and low-pressure cycles.…”