Lipid Extraction Methods from Wet Microalgal Biomass

Energy security has emerged as a significant worldwide concern, and numerous studies are being conducted to find environmentally friendly and economically feasible alternatives. The utilization of renewable energy is the only approach that seems to be able to fulfil future demands. Although there are many different renewable energy sources currently in use, microalgae (MA) appear to have a promising future as a source of carbon–neutral biofuels due to their special characteristics, such as their suitability for growing in open ponds needed for the production of a commodity product, high CO2-sequestering capability, and ability to grow in wastewater, seawater, or brackish water. They also have high lipid productivity. The cost-effective and reliable extraction of lipids is the main process bottleneck in the development of microalgal biofuels. This article’s goal is to provide a thorough analysis of the different microalgae lipid extraction techniques that have been developed to date, as well as to analyze their benefits and drawbacks. Apart from some of the most recent extraction methods, the article covers all aspects of lipid extraction techniques, including solvent extraction procedures, mechanical approaches, and solvent-free procedures. For this technique to be successfully implemented at the production scale, more studies in this field are necessary.