How are algal biofuels made?
Producing biofuel from algae isn't quite as simple as skimming the green stuff from the surface of a pond and pumping it into our cars. In fact there is no one single way to grow algae, which is one of its strengths as a biofuel feedstock.
Quick Links:
This diagram presents the general framework of biofuel production from algae:
1. Cultivation
The first step of the process involves algal cultivation. The algae must be grown in optimal conditions in order to utilise light energy to grow and mulitply in numbers. The two main methods of cultivation are:
-
Open ponds
-
Closed bioreactors
To learn more about these two systems, please follow the link to the next page:
After the cultivation, the algae must go through a series of downstream processess.
2. Harvesting
This involves seperating the algae from the growing medium. There are many different methods that can be used to do this but selection normally depends on the species of algae used.
To learn more about some of these methods and future developments in this area, please follow this link:
3. Extracting
The final part of the algal processing is extracting the oil from the harvested algae. This step of the process poses the greatest challenge facing the production of biofuels from algae as it requires large energy requirements, detracting from the overal sustainability of algal biofuels as well as providing huge financial costs. Current techniques revolve around mechanical and chemical methods of extraction, eaching having their drawbacks. Many systems use a combination of these methods. Breakthroughs in this area are likely to be the key to a cost efficient and sustainable algal biofuel.
The US based company Algenol, have claimed to simplify extraction processess by genetically engineering cyanobacteria species to produce ethanol directly. To learn more about this technique, follow the link:
As the industry continues to grow, so too does the technology involved in optimising productivity and minimising running costs. To discover more about improvements to current systems and future innovation, please follow the link below:
Future innovation