| Renewable Energy entrepreneurs are now looking | | | | the oil from oilseeds, and these methods apply |
| for the best bioreactors with the right stuff. What | | | | equally well for algae too: |
| is the right stuff you ask? Well it has to be a | | | | - 1. Expeller/Press |
| algae farm that meets a number of challenges: be | | | | 2. Hexane solvent oil extraction |
| affordable, scalable, able to handle variable | | | | 3. Supercritical Fluid extraction |
| temperatures at different client sites. | | | | - Expeller/Press |
| Low Cost of Implementation | | | | - Expression/Expeller press-When algae is dried it |
| The first area of concern is always the cost. As | | | | retains its oil content, which then can be "pressed" |
| with all systems of a commercial scale, cost is | | | | out with an oil press. Many commercial |
| king. The technology at this point has many faces | | | | manufacturers of vegetable oil use a combination |
| to include row crops, large open pond systems, | | | | of mechanical pressing and chemical solvents in |
| race way systems and photo-bioreactors. Thy | | | | extracting oil. |
| system you choose must have nutrients to feed | | | | - While more efficient processes are emerging, a |
| the algae, water and sunlight. Your carbon dioxide | | | | simple process is to use a press to extract a |
| inputs can be active or ambient air. Cross | | | | large percentage (70-75%) of the oils out |
| contamination of the algae is a concern, but | | | | of algae. |
| intended use of the algae will be your guide. | | | | - Hexane Solvent Method |
| Continuous Harvesting | | | | - Algal oil can be extracted using chemicals. |
| Harvesting the algae will always be a concern | | | | Benzene and ether have been used, but a popular |
| depending on the system. It will take more effort | | | | chemical for solvent extraction is hexane, which is |
| to harvest algae from an open pond system than | | | | relatively inexpensive. |
| it would from a continuous harvesting | | | | - Supercritical Fluid Method |
| photo-bioreactors. Continuous harvesters do just | | | | - Supercritical extraction involves, pressure and |
| that, always harvest algae cake, at this point you | | | | heat to burst algal cell walls. |
| will only need staff to move the algae cake to | | | | No matter what algae medium you chose just |
| the next stations for drying and oil extraction. | | | | make sure it meets your needs and production |
| Oil Extraction | | | | goals. |
| - There are three well-known methods to extract | | | | |