15% seems very low indeed !! I have used this method for years with much higher yields - also see page 196 of the same reference for recoveries of 92% - may depend on the matrix being extracted.

15% recovery by the Bligh & Dyer method is almost nothing! I would be very surprised at discovering that I have been working so many years on phospholipids with nothing!

I agree that recovery is more than 90% in my hands, and that a further homogenization/wash of the first pellet with H2O/CHCl3/CH3OH 1:1.25:2.5 yields even more.

Bligh-Dyer method is one of the most abused methods ever. I have seen a lot of solvent proportions!. The authors were very specific when they reported the method, and water seems to be crucial in the recovery. Obviously that matrix can also affect. Checking the original sources is a good idea for me when data seems to be contradictory or strange. 

In my experience, Folch and Blight-Dyer methods are the best to assure a good isolation of lipids, mainly phospholipids. Recently, some researchers have started to use modification with MTBE but I have not obtained good results with this solvent. 

For those still interested. The question refers to the following paper: Cooney, M., Young, G., & Nagle, N. (2009). Extraction of bio‐oils from microalgae. Separation & Purification Reviews, 38(4), 291-325.

A careful look at what is written learns that the 15% does not refer to the lipid recovery. But to the lipid content (in weight %) “the lipid content of the Chlorella prototheocoides was also determined by outside analysis (National Food Lab) to be 51% using an acid hydrolysis method certified by the Association of Analytical Communities (AOAC 922.06).” and “The lipid- containing chloroform phase was collected and the solvent evaporated to recover the extracted lipids. In our work a final lipid yield of only , 15% (wt %) was usually obtained, a value well below the 51% (w/w) reported by the National Food Lab analysis.”

It furthermore indicates that the maximum starting value was round 36% and a re-suspension step increase the yield to 22%. So purely based on this the lipid recovery is at least 22/36 = 61%. Not extremely good but certainly not as dramatic as 15%.

Anyway, it is obvious that lipid recovery efficiency depends on numerous factors and depends highly on which class of lipids is the main focus, see for example Jones, J., Manning, S., Montoya, M., Keller, K., & Poenie, M. (2012). Extraction of algal lipids and their analysis by HPLC and mass spectrometry. Journal of the American Oil Chemists' Society, 89, 1371-1381. https://repositories.lib.utexas.edu/server/api/core/bitstreams/fe0b216b-3325-4c1e-bccf-add5f18c84a1/content