Thursday, October 15, 2009

Basic Science of Algae Oil

Part 1 of Algae Oil Analysis Report

Before beginning an analysis of algae oil, I believe it is important to understand at least some of the basic science. In this way, an investor has the means to better evalutae different cultivation and production methods of various species of algae. In addition, she can compare algae oil with other biofuels, in terms of yields and cost efficiencies.

One of the ironies of biofuels and fossil fuels is that both involve the production by living plants of biomass through the process of photosynthesis. (1) The difference, of course, is a few milllion years. Fossil fuels contain carbon that has been out of the carbon cycle for eons. When it combusts, the carbon is released as carbon dioxide (CO2), and thus upsets a delicate balance in our atmosphere. (2) Climate scientists attribute this "late" release as one of the major causes of global warming.

Since biofuels and fossil fuels are almost identical in chemical make-up, biofuels such as algae oil also release CO2 into the atmosphere when they combust. The difference is that since algae oil was recently living, the CO2 also was only recently taken out of the atmosphere during photosynthesis. In essence algae oil is CO2 neutral and does not add to CO2 to the environment. Of course, it also doesn't reduce the amount of CO2, as many wind power, geothermal and tidal power advocates are quick to point out. Nor, of course, do the aforementioned, although they are not part of the carbon cycle.

One of the distinct advantages of algae is that almost the entire organism can use sunlight during photosynthesis to produce biomass. (3) The amount of lipids, or oils, produced varies with each specie, with some approaching 50% lipid concentration. Algae produce lipids for energy storage in the form of triacylglycerides (TAGs). TAGs are converted into bio-diesel through a process called transesterifcation, in which the TAGS, in the presence of simple alcohols and a catalyst, produce the fuel. This bio-diesel fuel has most of physico-chemical properties of petroleum diesel fuel. (4)

To be competitive with fossil fuels, however, biofuels need to equal or surpass the costs of producing fossil fuels. Many feel that algae is the most promising prospect since it is able to produce more biomass per acre-year than any other plant under consideration. Algae also has the added advantage of not being a plant used in the production of food, such as the conversion to ethanol of corn, a feedstock for cattle. Despite this promising start, there are cultivation and production challenges that must be overcome. I will discuss these challenges in Part 2, but the difficulties center around finding an algae strain with "a high lipid content and fast growth rate that isn't too difficult to harvest, and a cost-effective cultivation system." (5)

(1) Biomass, Wikipedia.
(2) Biomass, Wikipedia.
(3) Algae fuel, Wikipedia.
(4) Algae FAQ, Sustainable Green Technologies, Inc.
(5) Algae fuel, Wikipedia.

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