How do I extract vegetable oil from algae?

I've just seen the fantastic instructable on growing algae en-mass, and have a few ideas for it. However, does anyone know how to then extract the vegetable oil from the algae? Thanks :)

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alfalfa2008 years ago
OK, I am a chemistry teacher, so here is what you do, first, you dry the algae. once it's dry you soak it in alcohol, then you strain it so the solids are not in liquid anymore. now you have a colored liquid that is alcohol and what ever came from the algae, you gently warm the alcohol and when the alcohol evaporates what is left is oil and some impurities. any alcohol can be used since it will all evaporate away when you warm it up. doesn't even have to be pure alcohol since you can warm it to 100 degrees and boil off any water that is in the solution as well. that is the short version of how to do it. if you are serious about this then you will need a reflux and distilling set up. google it, it's complicated.
how about the amount of oil produced in algae ?
As a chemistry teacher you should know that the alcohol would boil at 78.4 Celsius, it's how distillation works...
and as someone who can read you should have noticed that I said that you can heat it to 100 degrees to get rid of the water if you are not using pure alcohol.
Sir, I need to know from which type of algea is used for edible oil............
The commercial extraction of oil from algae typically starts with simple pressure - the oil can be squeezed from the algae, as for any other vegetable oil.
ohowson (author)  Kiteman8 years ago
That could be worth a go. Any suggestions on what would be the best way to do that? drain-dry the algae, give it a squeeze in something resembling a caffetierre and then allow water/oil/contaminants to stand to separate them all? I don't currently have any use for the oil, but am thinking about buying an old diesel car and attempting to become self-sufficient.
Dry pressing with an expeller press is widely viewed as the most efficient method currently. A good survey of extraction methods is available from the good folks at oilgae.

Filter with a 400 mesh screen or similar silkscreen material.

Any number of online sites (including this one) that have plans for a press.

For smaller quantities and experiments you can try an arbor press

Here's a link for a simple two ton screw press that might produce some results for you.


And a lovely set of machine drawings for a more sophisticated press

PKTraceur8 years ago
I've tried extracts, and am in the process of making Vanilla extract, (as I LOVE to cook, :) ;) ) so basically, I just stuck three vanilla bean pods in a (pint? quart?) Of rum, and this is month two of fermentaion and extraction. Dont expect it to be fast...
sallost8 years ago
you could "break" the fibers by mixing the stuff and after that you could extract the fat by using a fat dissolving product like pure alcohol. Let the alcohol evaporate and you should have you oil. I'm not sure this would work but my chemistry book enplanes the process like above.