Algae Biofuels

After the process of extracting the oil from algae, the resulting product can be converted to biodiesel. The biodiesel produced from algal oil has physical and chemical properties similar to diesel from petroleum, to biodiesel produced from crops of first generation and compares favorably with the International Biodiesel Standard for Vehicles (EN14214) (Brennan and Owende 2010).

Contrasting to other sources of feedstock to produce biofuels, algae-based bio­fuels present several advantages. These advantages comprise:

1. Capability of producing oil during all year long; therefore, the oil productivity of microalgae is greater compared to the most efficient crops;

2. Producing in blackish water and on not arable land (Searchinger et al. 2008); not affecting food supply or the use of soil for other purposes (Chisti 2007);

3. Possessing a fast-growing potential and several species has 20-50 % of oil con­tent by weight of dry biomass (Chisti 2007);

4. Regarding air quality, production of microalgae biomass can fix carbon dioxide (1 kg of algal biomass fixes roughly 183 kg of CO2) (Chisti 2007);

5. Nutrients for its cultivation (mainly nitrogen and phosphorous) can be obtained from sewage; therefore, there is a possibility to assist the municipal wastewater treatment (Cantrell et al. 2008);

6. Growing algae do not require the use of herbicides or pesticides (Rodolfi et al. 2008);

7. Algae can also produce valuable coproducts, such as proteins and biomass; after oil extraction, the coproducts can be used as animal feed, medicines, or fertilizers (Spolaore et al. 2006; Brennan and Owende 2010), or fermented to produce ethanol or methane (Hirano et al. 1997);

8. Biochemical composition of algal biomass can be modulated by different growth conditions, so the oil yield can be significantly improved (Qin 2005); and

9. Capability of performing the photobiological production of “biohydrogen” (Ghirardi et al. 2000; Ferreira et al. 2013).

The above combination of the potential for biofuel production, CO2 fixation, wastewater treatment, and the possibility of production of biohydrogen highlights the potential applications of the microalgae cultivation.

Compared to other biofuel technologies, the most favorable factors for the culti­vation of microalgae for the production of biofuels are they can be grown in brack­ish (salt) water, on non-fertile land, and the oil yield production is far superior.