Usage of a switchable-polarity solvents (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and an alcohol has been proposed for extracting hydrocarbons from dried and water suspended microalgae like Botryococcus braunii.It seems the use of DBU/octanol method resulted in higher yield of hydrocarbons from both the freeze dried and wet  algal samples as  compared to n-hexane and chloroform/methanol.

1.Extraction of hydrocarbons from microalga Botryococcus

braunii with switchable solvents by Samorì, C., Torri, C., Samorì, G., Fabbri, D., Galletti, P., Guerrini, F., Pistocchi, R.,Tagliavini, E., 2010. . Bioresour. Technol. 101, 3274–3279

2. Extraction of oil from microalgae for biodiesel production: A review by 

Ronald Halim ⁎, Michael K. Danquah, Paul A. Webley biotechnology advances(30) 2013.

Wahlen et al., 2011 proposed a simultaneous extraction and transesterification. This is also known as direct transesterification or in-situ transesterification. Both thermochemical liquefaction and pyrolysis is considered   the most technically

feasible methods for conversion of algal biomass-to-biofuels, after the extraction of oils from algae. 

Hi! Scientists use the extraction of supercritical carbon dioxide to extract lipids from the biomass of microalgae.

There are many studies on the application of the method of Bligh and Dyer extraction of lipids for biomass. In most cases a mixture of solvents (polar solvent + nonpolar solvent ).

Interesting articles on this topic:

http://www.ncbi.nlm.nih.gov/pubmed/22272135

http://www.sciencedirect.com/science/article/pii/S1350417712001721

http://link.springer.com/article/10.1007%2Fs11746-011-1903-z#page-1

The methodology used is highly dependent upon what your scale is. Also, do you plan to filter or centrifuge the material to concentrate it, and do you plan to dry the material (and how).

In large scale production of some oils from algae, I have seen high shear mixers or ultrasonics used to rupture the cell membranes and then extraction with some non-polar solvent or solvent mixture. For the highest efficiency extraction, It would probably be best to completely dry the algae prior to extraction with a non-polar solvent, but this is not necessarily the optimal choice for large scale commercial extraction.