Although many new technologies have been developed to extract straight vegetable oil from algae, this section specifically describes the single-step extraction process developed by OriginOil, Inc.

The single-step extraction process begins with the mature algae entering the system as an algae and water suspension. Before entering the extraction tank, the stream is subjected to pulsed electromagnetic fields and pH modifi­cation in a process known as quantum fracturing. As the terminology implies, quantum fracturing creates a fluid-fracturing effect, thereby mechanically distressing algae cells [33]. The electromagnetic fields are generated using a low-voltage power input and the pH is modified using carbon dioxide, which helps optimize electromagnetic delivery and assists in cell degrada­tion. The electromagnetic field created causes algae cells to release internal lipids. After quantum fracturing, the processed culture passes into a grav­ity clarifier and a return culture stream recycles into the inlet stream. The gravity clarifier separates the processed culture into layers of oil, water, and biomass. The lipid layer exit stream produces SVO and the water layer exits via a recycle stream to the bioreactor. The biomass can then be harvested for a number of purposes including livestock feed, ethanol processing, and bio­mass gasification. A schematic of the OriginOil single-step extraction pro­cess [34] is shown in Figure 2.4.

This innovative method can extract approximately 97% of the lipid oil contained in algae cells. Typical extraction values for expeller press extrac­tion and supercritical fluid extraction are approximately 75% and 100%, respectively, meaning this method would be competitive with industrial significance. This process does not require heavy machinery, chemicals, or dewatering of the feedstock and is thus claimed to use much less energy than traditional extraction processes.

The OriginOil single-step extraction process is an enhancement to the traditional algae oil extraction methods. The unique quantum fractur­ing method of extraction utilized by the process reduces the cost of pro­cessing by eliminating the need for chemical input or energy-intensive machinery. As shown in the flowsheet, the OriginOil process uses a radi­cally different approach in oil extraction which is based on a sequence of oil extraction^solids separation^dewatering basically in a single integrated

step, whereas the conventional approach follows a sequential order of sol­ids separation^dewatering^oil extraction [33]. As the result of this novel process alignment, no initial dewatering is required, substantial energy sav­ings can be expected, and the capital expenditure becomes reduced. With the biodiesel and bio-oil industries’ growth, single-step extraction technology will prove to be an invaluable tool for keeping algae-derived fuels competi­tive with petroleum.