Algae can be grown two different ways, raceway ponds and photobioreactors (More in the technology section). Either way the growth process is similar.
Step 1: Provide light to the algae 12 hours a day. Keeping the algae in darkness for the other 12 hours provides the algae time to go through cellular respiration, a vital processing the health growth of the algae.
Step 2: Provide nutrients, such as nitrates and phosphates. Algae do not require phosphate and nitrates to grow, they just grow faster and healthier.
Step 3: Provide carbon dioxide to the algae via air pump. Ambient CO2 will work fine, however pure CO2 will help the growth process.
Step 4: Remove approximately half of the algae every 24 hours to prevent light starvation.
Currently there are two main steps to extract oil from algae:
Oil Press: An oil press is a device that exerts mass amounts of pressure used to extract the oil from oilseed crops such as soybean, palm and now algae. It does this by simple squeezing. This process usually extracts less than 70% of the oil from the crops. What’s left is algae cakes. That’s where solvents come into play.
Solvents: After the algae has been pressed into cakes, a solvent can be used to extract up to 90% of the remaining oil. A solvent is a liquid, capable of dissolving another substance. This is done by subjecting said cakes to a solution usually containing n-hexane, which is a potent solvent.