Two Kansas State University Engineers have designed a new algae production system that could reduce the cost of biodiesel and help the U.S. Government to change from fossil fuel dependency to a renewable power source.The idea is to start mass production on ocean level, using very large supporting platforms. Just by comparison, soybeans produce around 50 gallons of oil an acre a year while algae can produce an average of 6,000 gallons. Algae production is not so cheap as current methods use ponds and bioreactor columns. As algae float around suspended in water, the harvesting methods are difficult, involving centrifuges and high electricity needs. With the actual production and harvesting methods, the cost of a biodiesel gallon goes up to $56.
The two engineers think that with the actual evolution of the technologies it will take us about 5 to 10 years until the target of $5 per gallon of biodiesel will be reached: “It will take that much time to really understand the fundamentals of large-scale algae production and to establish pilot projects.” The two scientists, Pei and Yuan, are well aware of the risks and do not recommend the large production of algae on land. They study the feasibility of large-scale algae production in the ocean and how to engineer the production system.
In order to make harvesting more simple, Pei and Yuan are working to identify oil-rich algae species that are inclined to settle down and grow on a solid surface: “We think there is tremendous potential for algae oil production if we grow it on big platforms and incorporate the ocean into the system. Half the cost of growing algae is in providing a steady supply of food and water, the growth medium. Ocean water offers those in abundance.”
After the first investigations, results seem to be positive. Two species of algae high in oil content and fast growing were analyzed and they attached very well to a stainless steel, thin film surface that was slightly dimpled. Also after the algae attach to the surface, they grow very well producing a green clump several millimeters thick: “Just like geckoes cannot walk on a perfectly smooth surface, our results indicate that the algae attach better on a slightly textured surface” said Yuan.
Considering these findings, the proposed ocean system could be a viable solution for mass production of algae. To also make the harvesting process very simple, the surface will roll up into the sunlight so algae can dry. A harvesting knife will cut the already dried algae and the surface will submerge once more offering support for the next generation of algae.
The designed system will not only help the US for which it was initially designed but the entire world. Its implementation will be the first step of reducing fossil fuel and finally eliminating their polluting usage.