Extraction of Bio-oils from Microalgae

TLDR: This review discusses existing extraction methodologies as they have and can be applied to microalgae and their potential as a unit operation that exists within the framework of an industrial‐scale microalgal cultivation process that extends from the production of biomass in photobioreactors to the fractionation of the recovered bio‐oil.

Abstract: A wide variety of terrestrial biomass feed stocks have been identified as suitable candidates for fractionation and conversion into biofuels. In particular, microalgae have been promoted as a future source of transportation fuels primarily because of their stated potential to produce up to 10 times more oil per acre than traditional biofuel crops. Their ability to grow relatively fast, be harvested on a daily basis, and grown in earthen ponds or closed photobioreactors that occupy marginal or poor crop lands using salt or brackish water, are often referenced. When these attractive traits are coupled with the potential to concomitantly harvest valuable co‐products such as biopolymers, proteins, and animal feeds, one can see why microalgae are often touted as biotechnology's “green gold”. The development of large‐scale microalgae farms, however, has been slowed by limitations in downstream processing technology. For example, traditional methods to dewater, extract, and recover bio‐oil from oil‐seeds possess...