Systems and methods for extracting lipids from and dehydrating wet algal biomass

1. A method comprising:

mixing algal biomass with an amphiphilic solvent;

separating the amphiphilic solvent from algal solids, or from any part of the algal biomass not dissolved in the amphiphilic solvent, to result in amphiphilic solvent, water and lipids;

evaporating most or substantially all of the amphiphilic solvent from the water and the lipids, to result in a mixture of the water and the lipids; and

separating the lipids from the mixture.

2. The method of claim 1 , wherein the amphiphilic solvent is selected from a group consisting of acetone, methanol, ethanol, isopropanol, butanone, dimethyl ether, and propionaldehyde.

3. A method comprising:

filtering a wet algal biomass through a membrane to increase a solid content of the wet algal biomass to between approximately 10% and 40% to result in a filtered algal biomass;

mixing the filtered algal biomass with an amphiphilic solvent to result in a mixture;

heating the mixture to result in a dehydrated, defatted algal biomass;

separating the amphiphilic solvent from the dehydrated, defatted algal biomass to result in amphiphilic solvent, water and lipids;

evaporating the amphiphilic solvent from the water and the lipids; and

separating the water from the lipids.

4. The method of claim 3 , wherein the wet algal biomass is filtered to increase the solid content to approximately 30%.

5. The method of claim 3 , wherein the amphiphilic solvent is selected from a group consisting of acetone, methanol, ethanol, isopropanol, butanone, dimethyl ether, and propionaldehyde.

6. The method of claim 3 , wherein the mixture is heated in a pressurized reactor.

7. The method of claim 6 , wherein the pressurized reactor is a batch or a continuous pressurized reactor.

8. The method of claim 3 , wherein the mixture is heated with microwaves, ultrasound, steam, or hot oil.

9. The method of claim 3 , wherein the amphiphilic solvent is separated from the dehydrated, defatted algal biomass via membrane filtration to result in amphiphilic solvent, water and lipids.

10. The method of claim 3 , wherein the amphiphilic solvent is separated from the dehydrated, defatted algal biomass via centrifugation to result in amphiphilic solvent, water and lipids.

11. The method of claim 3 , wherein the separating includes decanting the amphiphilic solvent from the dehydrated, defatted algal biomass to result in amphiphilic solvent, water and lipids.

12. The method of claim 3 , wherein the separating of the water from the lipids includes adding a nonpolar solvent.

13. The method of claim 12 , wherein the nonpolar solvent is propane, butane, pentane, hexane, butene, propene, naphtha or gasoline.

14. The method of claim 3 , wherein the separating of the water from the lipids includes decanting the lipids without a nonpolar solvent.

15. The method of claim 3 , wherein the separating of the water from the lipids includes adding a nonpolar solvent in a continuous liquid-liquid extractor.

16. The method of claim 15 , wherein the nonpolar solvent is evaporated from the lipids by distillation or flash evaporation.

17. The method of claim 3 , wherein the separating of the water from the lipids includes adding a nonpolar solvent in a batch vessel and decanting the batch vessel.

18. The method of claim 17 , wherein the nonpolar solvent is evaporated from the lipids by distillation or flash evaporation.

19. The method of claim 3 , wherein the wet algal biomass is centrifuged to increase the solid content to approximately 30%.

20. The method of claim 3 , wherein the evaporating the amphiphilic solvent from the water and the lipids is performed by flash evaporation, distillation or by pervaporation.