Renewable power entrepreneurs are now looking to find the best bio-reactors with all the right stuff. What is the right stuff you ask? Well it needs to be a algae PBR that meets numerous challenges: be affordable, scalable, ability to manage variable climates at different customer locations.
Inexpensive to Implement
The first subject of concern is definitely the cost. As with all systems of a commercial size, cost is very important. The technological innovation at this time has many faces to include row crops, big open pond systems, raceway pond systems and PBR’s. The product you choose should have nutrients to nourish the algae, water and sunshine. Your carbon dioxide inputs can be active or ambient air. Cross contamination of the algal mass is a concern, but the intended use of the algae shall be the best guide.
Constant Harvesting
Harvesting the algae will always be a concern based on the system. It will take more effort to harvest algal biomass from an open pond system than it would from a continuous harvesting algal PBR. Continuous harvesters do just that, constantly harvest algal cake, you now will only need staff to move the algal biomass to the next stations for drying out and oil extraction.
Oil Removal
* There are 3 well-known methods to remove the oil from oilseeds, and these techniques apply equally well for algal biomass too:
1. Expeller/Press
2. Hexane chemical oil extraction
3. Supercritical Fluid extraction
* Expeller/Press
* Expression/Expeller press-When algal mass is dried out it keeps its oil content, which then can be “forced” out with an oil press. Many commercial manufacturers of vegetable oil use a combination of mechanical pressing and chemical solvents in extracting oil.
* While better processes are emerging, an easy process is to use a press to remove a large percentage (70-75%) of the oils from algae.
* Hexane Solvent Method
* Algae oil can be removed utilizing chemical substances. Benzene and ether have been used, but a popular chemical for solvent extraction is hexane, which can be relatively inexpensive.