BioDiesel from Algae Oil Extraction By: Kyle Fricker

Background Information Acre-by-acre microalgae can produce 30-100 times the oil yield of soybeans for biodiesel production Algae can grow on marginal land and in brackish water The biomass left-over from oil-pressing can either be fed to cattle as a protein supplement, or fermented into ethanol (and possibly recycled into the biodiesel refining process)

Oil Extraction Techniques

Sonication Idea: Send ultrasonic sound waves through algae/water solution, break algal cell walls, let oil collect at the top of the liquid and skim off Currently used in ponds to kill off troublesome algae Positive: environmentally benign, relatively low cost Negative: not effective yet, most internet sources claim using ultrasound along with other methods – microwaves, solvents, mechanical presses

Mechanical Press Mortar and pestle (not very economical) Screw Press – numerous online sources claim to use this method with average yields Must be sized quite small since algal cells are microscopic Dutch company, AlgeaLink, sells screw presses along with photo reactors for growing the algae. They allege to yielding 50% oil by mass, but the cheapest press costs € 7300 Most industrial processes mechanically press, then treat the sludge with a solvent to extract the oil that remains

Osmotic Shock Grow algae in high saline solution and harvest into a sludge After dumping the sludge into distilled water, the cells theoretically will burst with the mass exodus of salts Oil can then be skimmed off the surface I did not find any experimentation on this method, yet the theory makes sense and experimentation is relatively easy

Freezing & Deconstructive Decompression Is it possible to freeze and thaw a batch of algae to break the cell wall? When they are frozen, the cells will expand Once allowed to thaw, the change in size could rupture cell walls allowing for the lipids to be released Similarly, if algae were compressed and rapidly decompressed, would the force on the cells be too much to handle? Not much, if any, research has been done on these ideas – yet they are easy experiments to perform

Solvent Extraction Widely used, high yields Expensive; deal with nasty chemicals Usually used in conjunction with other extraction techniques

The Plan It seems the best yields and time consumption can be achieved by combining a few of the aforementioned I will be looking into sonication, freezing, deconstructive decompression, and possibly osmotic shock Results will be viewed under a light microscope

Algae-to-BioFuel This stuff is actually happening PetroSun has a commercial algae-to-biofuel plant in southern Texas that opened in April 2008. Here’s a picture of the facility taken from Google Earth

Fossil Fuel is Fossil Thinking