Microalgae biofuel is an alternative fuel source made from the oils and carbohydrates found in algae. The process of making biofuel from algae is adapted from similar biodiesel production methods using processes, such as transesterification and fermentation, to create fuel from plants like corn and soybeans. The use of algae for the production of biodiesel and crude oil is often more cost-effective because the hydroponically grown algae produces more oil than similar quantities of plants which grow in soil.
The process of making microalgae biofuel is fairly simple. Algae is grown in open ponds, closed loop systems, or photobioreactors. This algae is harvested and dried for use in the microalgae biofuel making process. The oils are then extracted from the algae and converted into biodiesel or a form of crude oil with a green coloration through transesterification. The remaining material is used to create bio ethanol or biobutanol using a fermentation process.
Algae farming methods have been an area of major concern for biofuel producers. Algae grows quickly as compared with other fuel crops, with an average harvest cycle of one to ten days. While algae can be successfully grown and harvested from open ponds, these ponds are subject to contamination. Closed loop systems and photobioreactors are designed to prevent the possibility of outside contamination but offer their own disadvantages in the form of harvesting difficulties, operating cost, and initial investment.
Due to the demand for a steady supply of sterile carbon dioxide (CO2), many closed loop systems and photobioreactors are designed to have a symbiotic relationship with industrial smokestacks. In this design, the algae farming equipment reuses the factory's CO2 emissions to fuel the growth of algae for biofuel production. It should be noted that, while microalgae biofuel is considered to be a green alternative fuel, it merely produces a neutral CO2 emission because the CO2 captured during the growing stage is released when the biofuel is burned. The benefit of using biofuels lies in the fact that these CO2 neutral fuels can eliminate additional atmospheric CO2 caused by burning CO2 positive fossil fuels.
Using microalgae biofuel provides several distinct benefits to industries and consumers. By growing algae for biofuel production, industries can lessen their impact on the environment, often obtaining tax benefits and government subsidies which are passed on to the consumer as lower prices. In some cases, industries can use and generate microalgae biofuel in the same vicinity, thus supplying fuel to the factory while generating the CO2 needed for the algae growing process. The advantages of using biofuels can also be seen in the reduced dependence on fossil fuels and lowered fuel costs, particularly in the aviation and transportation industries.