Extraction of Oil from Algae
Though the harvest of oil or other type of fuel quantities from algae are between 10 and 100 times more than comparable energy crops, and even though algae can flourish almost anywhere, ascertaining its superiority in this field over food crops, the energy sphere of algae is still in a nascent stage. Though algae make fine bioremediation components, with the extraordinary capacity to soak up enormous CO2 quantities, playing a vital function in sewage systems, not much is known of the potential and current status of oil extraction from algae, which also happens to be the single most important feedstock that can totally substitute the earth’s utilization of transportation energy.
As far as the measures are concerned, the concepts are not too complicated. From the medium of its growth, algae need to be taken out by way of a proper extraction process. Then, these algae, even in its undried, wet form, can be used to separate fuel. Now, the three popular procedures to separate oil from oilseeds hold good for oil extraction form algae as well.
In the press or expeller extraction method, the algae need to dried, and then pressed or squeezed out of its retaining oil component. Numerous business-level vegetable oil producers employ a mixture of motorized pressure and certain compound solvents for their oil extraction methods. Similarly such an easy procedure of employing a press to separate between 70 percent and 75 percent of oil from algae remains popular even in the face of current development of other more effectual methods.
In the hexane solvent extraction method, extraction of oil from algae can take place with the employment of chemicals. While ether and benzene are known to have been utilized in certain cases, hexane remains the most preferred for this purpose, mainly because of its low cost and high availability. This particular method of oil extraction can be used by itself, or employed along with the press or expeller measure. While maximum oil can be separated with the expeller extraction method, the residual pulp can be blended with cyclo-hexane to remove the oil content left over. This happens by filtering out, through distillation, the oil and cycle-hexane dissolve solution. The mixture of the two procedures, that is, utilization of both the cold expeller and hexane solvent, together usually results in separation of nearly 100 percent of the complete oil content of the algae.
In the supercritical fluid extraction process, nearly the entire quantity of algae oil can be harvested by itself, with the help of particular instruments for containment and pressure application. This procedure involves liquefying carbon dioxide with pressure application, and the subsequent heating of the same to the unique temperature, where the compound exhibits both qualities of oil and gas. This special fluid is then utilized as solvent for oil extraction from algae.
