Biodiesel from Microorganisms: A Review

Biodiesel is a good substitute for fossil fuels because it is renewable, environmentally friendly, and biodegradable. Biodiesel is often classified into three generations, the third‐generation biodiesel, often manufactured using lipids from microorganisms, especially microalgae and yeast, which can produce biomass with lipid content up to 70% by weight (dry). After cultivation of microorganisms, lipids in cells need to be recovered. This Review attempts to illustrate the entire process of producing third‐generation biodiesel and suggests ways of promoting it. The Review defines biodiesel; touches upon different standards of biodiesel and performance of engines powered with biodiesel; summarizes the methods of cultivating microalgae and yeast, including reactors, parameters, media, and fermentation processes; and also introduces both traditional and modern methods of recovering lipids from biomass, suggesting ways of making the recovery more efficient and less expensive.