An algocarburant is a fuel based on lipids extracted from microalgae. Algofuels are "third generation" biofuels potentially capable of replacing the controversial "first generation" biodiesels obtained from vegetable oil from terrestrial plants. Algae fuel, algae biofuel or algae oil is an alternative to liquid fossil fuels that use algae as a source of high energy oils. Like fossil fuel, algae-based fuel releases CO2 when burned, but unlike fossil fuel, algae-based fuel and other biofuels only release newly-captured CO2 into the atmosphere through photosynthesis. as the algae or plants grow. A seaweed matures and is transformed into biofuel in just over two days, while resources such as fossil fuels take millions of years to transform plant matter into oil.