1. BioDiesel from Algae
Oil Extraction
By:
Kyle Fricker

2. Background Information
Acre-by-acre microalgae can produce 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)

3. Oil Extraction Techniques

4. 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

5. 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

6. 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

7. 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

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

10. 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

11. 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

12. Fossil Fuel is Fossil Thinking