Production.

Energy security and conservation of environment are two key factors, indispensable for the growth, progress and sustainability of the human race. The fossil fuels reserves are depleting at an alarming rate; however, their major role in green house gases emissions is becoming even more dangerous for the environmental and ecological balance. Driven by these facts, world over, the researchers are determined to find alternative renewable and potentially carbon neutral biofuels as alternative energy sources. The alternate energy sources like the first generation biofuels derived from food crops such as maize, sugarcane, rapeseed and sugar beet caused a great worry to world food markets and exaggerated the water shortages. Second generation biofuels obtained from lignocellulosic residues of agriculture and nonfood crops address some of the issues; but, there is concern over land use changes. As a consequence, third generation biofuels specifically derived from microalgae are considered to be commercially viable alternative energy sources, free from major disadvantages associated with first and second generation biofuels. Like plants microalgae are photosynthetic in nature, known to produce carbohydrates, proteins and lipids in large quantities in short durations of time. This review focuses on various technologies used for the production of biofuels from algae. The outcome of the study reveals that the microalgae-derived biofuels could gradually replace the petroleum diesel to meet the growing energy needs.