In addition, the organic solvents normally selected in conventional methods are regarded as highly toxic and
environmentally unfriendly. These shortcomings hinder the
application of conventional methods in industrial lipid
extraction, despite the high extraction efficiency. Besides the
previously mentioned traditional methods, there have been
several new lipid extraction technologies in this field recently,
such as supercritical fluid extraction,2 ultrasound-assisted
extraction,8 simultaneous distillation and extraction process,9
and microwave-assisted extraction.10 These methods, which
require no energy to dry the biomass, can be directly applicable
to a wet feedstock. Unfortunately, high temperature, long
extraction time, or high pressure are still required in most cases.
Therefore, the technologies of lipid extraction are only limited
to laboratory scale