Ethanol from Algae

Algae have a tendency to have a much different makeup than does most feedstocks used in ethanol, such as corn and sugar cane. Ethanol from algae is possible by converting the starch (the storage component) and Cellulose (the cell wall component). Put simply, lipids in algae oil can be made into bio-diesel, while the carbohydrates can be converted to ethanol.
Algae are the optimal source for second generation bioethanol due to the fact that they are high in carbohydrates/polysaccharides and thin cellulose walls
It’s not that it’s difficult to make ethanol from algae.

 Veridium Corp is a subsidiary of GreenShift. (Mar 2006)

The real problem is that there are so many more valuable products to produce from it, such as carrageenan, agar, and dozens of valuable compounds. In comparison, alcohol is a low-priced product.

Algae Species for Ethanol Production

Some prominent strains of algae that have a high carbohydrate content and hence are promising candidates for ethanol production.

• Sargassum
• Glacilaria
• Prymnesium parvum
• Euglena gracilis

Process behind Ethanol from Algae 

Fermentation process to produce ethanol include the following stages:

(a) Growing starch-accumulating, filament-forming, or colony-forming algae in an aqua culture environment;
(b) Harvesting the grown algae to form a biomass;
(c) Initiating decay of the biomass;
(d) Contacting the decaying biomass with a yeast capable of fermenting it to form a fermentation solution; and,
(e) Separating the resulting ethanol from the fermentation solution.
Initiating decay means that the biomass is treated in such a way that the cellular structure of the biomass begins to decay (e.g., cell wall rupture) and release the carbohydrates. Initiating decay can be accomplished mechanically, non-mechanically. The yeasts used are typically brewers' yeasts (Saccharomyces cerevisiae and Saccharomyces uvarum). Besides yeast, genetically altered bacteria know to those of skill in the art to be useful for fermentation can also be used.


Ethanol from De-oiled Algae
Overall, the algal biomass comprises three main components – Carbohydrates, Proteins and Lipids. Once the lipids have been extracted the left-over cake is primarily composed of carbohydrates and proteins. Carbohydrates in the left-over algae can be converted into sugars. Depending on the strain, the sugar can either be simple or complex. Thus, the left-over be used as feedstock for ethanol.
Algae cake that is left over after extraction of oil for bio-diesel can be converted into ethanol through fermentation of the extract. This gives rise to the interesting possibility of producing both biodiesel and ethanol from algae! Add to this the fact that fermentation of algae extract to ethanol releases CO2, which can again be fed to grow more algae. Such a closed loop presents an attractive potential on which some initial trials are on-going.

Adapted from  http://www.oilgae.com

Oilgae is the premier resource for the global algae energy industry. Started in 2006 with a dedicated focus on algae energy, Oilgae today serves as a crucial platform and opinion-leader for this industry.
The Oilgae team is frequently interviewed by leading world media and frequently presents at seminars and conferences. Some of the media that Oilgae has been mentioned in are: WorldChanging (Columbia University), BBC, Salon Magazine, Los Angeles Times, New York Times, Wired, India Times and more.
Oilgae today is so synonymous with algae energy that many people worldwide use Oilgae as the word to refer to oil from algae!