Integrated Processing of Microalgae for Valuable Food Ingredients, Chemicals and Fuel Production

Lipid-based biofuel production by microalgae has captured interest of researchers due to microalgae’s high biomass yield and ability to synthesize and accumulate large quantities of lipid. However, high cost of algal cultivation and processing has limited the commercialization of algal fuel production. Developing a microalgae biorefinery strategy, i.e., using every components of algal biomass for fuels and chemicals production is a feasible approach for commercially utilization of the algal biomass.

This study reports a hybrid processing for treating the microalgae Schizochytrium limacinum. Crude glycerol, a major byproduct in biodiesel production plants, was used as substrate for producing high content of algal oil containing DHA (22:6, n-3), a high value omega-3 polyunsaturated fatty acid with beneficial effects on human health.  The residues after oil-extraction from S. limacinum were then catalytically pyrolyzed on a micro-furnace pyrolyzer with zeolite catalyst being used. Aromatics and ammonium was generated from this catalytic pyrolysis process. Among the aromatics, benzene, toluene and xylene, which are valuable basic petrochemicals,were the dominant ones. Most of the nitrogen in the residues was released in ammonium form, which may be in turn used as nutrient for algal culture. In summary, all the components in the biomass of the S. limacinum were utilized for producing chemicals, fuels and value-added products which can be future enhanced the economic for algal industry.