The process of making oil from algae is quite simple. The algae are grown in ideal conditions, which maximizes their creation of triglycerides, also known as lipids. The lipids are the basic fats created by nearly all living things and the lipids from the algae are the source of biodiesel (Algal Biofuels II.). The oil is extracted form the algae by either chemically lysing the cells into a solvent, or by pressing the algae, which forces out the oil and sugars into a solvent. As shown in the diagram, the solvent separates the sugars from the oil and the pure oil can then be harvested and converted into biodiesel.
Vertical Growth/closed loop production Vertical growth/closed loop production is a much faster and more efficient alternative to open-pond systems. With vertical growing, algae are cultured in clear plastic bags, which allow them to be exposed to sunlight on two sides. The bags are stacked high and protected from the rain by a cover. The extra sun exposure and constant flow of nutrients increases the productivity of the algae, which therefore increases oil production. The bags also protect the algae from contamination (Newman). |
Closed-tank Bioreactor
Closed-tank bioreactor plants help increase oil rates even further. Instead of growing algae outside in the vertical growth process, indoor plants are built with large, round drums that grow algae under ideal conditions. The algae are manipulated into growing at maximum levels and producing as much oil as possible and can be harvested every day. This yields a very high output of oil for biodiesel. Closed bioreactor plants can also be placed near energy plants to capture carbon dioxide emitted from the plants that would otherwise pollute the air (Newman).
The picture above is a proposal for how some algal biodiesel farms would be built and work. Any algae farms requiring sunlight would be built on non-arable land so as not to decrease food or other crop production. This actually works better for sun-grown algae because the algae receives more sunlight in the desert. As aforementioned, farms or plants would be built next to power plants or other high carbon dioxide emitting buildings in order to use the carbon dioxide to feed the algae. Ideally, the oil would be converted into biodiesel onsite and immediately shipped to destinations around the country and possible around the world.
The picture above is an actual layout for an algae farm currently under construction on the Gulf coast of Mexico. With the two philosophies of algae growth (dark and light), sun-powered algae farms would be constructed in the desert, ideally near a body of water for shipping. Algae grown without sunlight would be grown near any power plant or other high carbon dioxide-emitting building.
