(421k) Determining the Role of Algal Biopolymers In Hydrolysis of Triacylglycerides to Free Fatty Acids

Microalgae are a third generation of biofuels and an alternative to woody biomass in production of liquid transportation fuels.  The main carbon rich components of algal biomass include protein, carbohydrates, and lipids.  The balance of these components within a specific algal species is a affected by the environment in which it is cultivated.  Proteins in algae can provide energy storage, structural support, and maintain internal function.  Carbohydrates, such as starch, provide energy storage and cell structure.  Lipids are involved in structure of the algae cells, energy storage, and are used as signaling molecules.

High lipid content in algae used for fuel processing is attractive due to the high yields per acre compared to terrestrial crops. Triacylglycerides (lipids) can be converted to free fatty acids via hydrolysis in subcritical water.  Subcritical water is attractive due to the elimination of organic solvents and catalysts, which can be difficult to remove and expensive.  This eliminates energy intensive drying steps prior to hydrolysis, allowing for algae, as received, to be processed.  High temperature can denature and char protein components.  These proteins are a valuable byproduct of algae useful as a livestock feed or food supplement.  The effects of polysaccharides and other constituents at subcritical conditions are also of interest to determine the behavior of algal species during hydrolysis. 

The focus of this research is evaluating the effects of pre-processing algal samples for hydrolysis of triacylglycerides to free fatty acids.  Extraction of algal constituents prior to hydrolysis impacts charring at elevated temperatures, conserves  profitable by-products, and can ease downstream material handling.