Our next step is to run the soxhlet to separate the lipids out by using the hydrolical cycle. We have been experimenting with running the soxlet with wet algae and dry algae.

The wet algae has had mixed results. In trial #1 we got 7 times as many lipids, but the lipids seemed less thick than in the dry algae. The next time we used wet algae, the experiment didn't work as well because the algae did not go through the thimble.

Our Soxhlet is either a 24 or 48-hour process. We start setting up the contraption by putting an Erlenmeyer bulb flask above a heating mantle that's set to heat to a little over 69°C (hexane's boiling point).

Next, we put an extraction tube on the Erlenmeyer bulb flask with a thimble filled with algae. At times, the algae is completely crushed, chunks, or wet. Usually the algae weighs around 55 g and the thimble weighs around 11.3 g. We then pour around 250 ml of hexane into he extraction tube - enough to make the hexane tip over the side tube plus a little extra.

We put a condenser connected to water on the top of the tube. When the hexane tips, the liquid goes into the Erlenmeyer bulb flask and is evaporated back up into the extraction tube and into the condenser, where the hexane cools down and turns back into liquid. The hexane then mixes with the lipids in the algae because they are both fat-based, and then tips back into the Erlenmeyer bulb flask and the process repeats again.

Hopefully the lipids have a higher boiling point then the hexane, so they don't evaporate too. At the end of 24 or 48 hours, we have our algae, lipids, and hexane.

We then either put the thick algae into pans or centrifuge it to separate the algae further. If we don't put the algae into the soxhlet immediately, we put it in the fridge.

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