The National Alliance for Advanced Biofuels and Bioproducts (NAABB) has selected three harvesting and one extraction technology for Phase II scale up development. The three harvesting technologies include an electrolytic flocculation system from Texas AgriLife Research (Texas A&M), new cross-flow membrane technologies from Pacific Northwest National Laboratory (PNNL), and the ultrasonic algal biofuel harvester from Los Alamos National Laboratory (LANL). The selected extraction technology is a specialized mesoporous nanomaterial technology for extraction of high value lipids, e.g., tocopherol, being developed by Iowa State University (ISU).

The electrolytic flocculation system utilizes technology developed for the wastewater treatment industry. It is therefore the most advanced of the selected technologies and has been demonstrated, by Texas AgriLife Research, for algal culture processing at scales of ~600 L/hr. The cross-flow membrane technologies utilize the well-known concept of cross-flow filtration to minimize surface fouling and cleaning issues.

The PNNL technology utilizes a new class of thin porous metal flat sheet membranes, recently invented, with uniform pores effective in capturing the small algae cells that are encountered in common biofuels systems, along with membrane materials and surfaces that are very promising in addressing common fouling problems caused by algae adhesion and/or bio-film growth.

The LANL technology is based on LANL’s R&D 100 Award-winning Ultrasonic Algal Biofuel Harvester. The ultrasonic harvester utilizes sound waves to concentrate and cause flocculation of the algae into a separate concentrated flowing stream.
The mesoporous nanoparticle technologies from ISU utilize nanomaterials with a selective binding agent that can efficiently bind specific molecules within the algal oils for extraction and has been demonstrated in the extraction of tocopherol from algal oil. All of these technologies have demonstrated high efficiency and energy minimization when compared to traditional technologies currently in the market.

The NAABB selected these four harvesting and extraction technologies for scale-up following a rigorous review. Five harvesting technologies and four extraction technologies being developed within the NAABB program were compared to each other and to market benchmarks for projected operational costs and energy consumption for this down select process.