CH391L/S13/Algal Biofuels

Algal biofuels represent various methods to produce highly reduced hydrocarbons from carbon dioxide using solar energy as the power source and algae, typically microalgae, as the machinery. The primary driving point for photosynthesis powered biofuels is that they do not increase the net carbon content in the air; every molecule of CO₂ released during combustion came from one molecule of CO₂ fixed during photosynthesis. Since their energy source is sunlight, algal biofuels are considered renewable. Algae are top choices in biofuel engineering due to their far greater photosynthetic efficiency and low growth requirements. In addition, countries that lack reserves of fossil fuels may desire economic independence by reducing imports through domestic fuel product.

Cultivation

One of the most distinct advantages of microalgae over other photosynthetic organisms is their tolerance and/or preference for marginal water sources[1]. This means that algal biofuels won't have to compete for resrouces like fresh water and arable land with food crops, unlike biofuels derived from corn and soybeans[2]. Most commercially relevant algal species grow well on either seawater or wastewater, both of which are inexpensive alternatives to freshwater[3].

iGEM Connection

The University of Washington's 2011 iGem Team attempted to use Fatty Acid intermediates into alkanes [4]. They used Acy-ACP Reductase (AAR) to convert long Acyl-ACPs into aldehydes, and then used Aldehyde Decarbonylase (ADC) to convert them into alkanes.

References

2. DOE biofuel datasheet

3. Microalgal Reactors: A Review of Enclosed System Designs and Performances

4. UW Diesel Production

5. Biodiesel production—current state of the art and challenges

6. Commercial production of microalgae: ponds, tanks, tubes and fermenters