The use of subcritical water in a continuous flow system was developed as a new method (Flash Hydrolysis) capable of transforming microalgae biomass into useful byproducts and biofuels intermediates. The new method allows us to work with very short residence times (6 to 12 seconds) making a more energy efficient process when compared to a batch process for hydrothermal liquefaction (HTL).Protein content in Scenedesmus spp. is more than 50% dw and Arginine can represent up to 30% (0.3 g Arginine/g protein) or more depending on the nitrogen source used in the growth media; when urea or ammonium salts are used the Arginine fraction is higher when compared to nitrate/nitrite salts. In the microalgae cell arginine plays an important role as an osmotic regulator, nitrogen storage for further lipid production (nitrogen deficiency conditions in the growth media) and as a structural component. This high protein content and the amino acid profile of microalgae Scenedesmus spp. makes it a potential source of good quality protein as well as for free amino acids production. In previous experiments it was observed that after flash hydrolysis liquefaction at 280�C about 60% of the microalgae nitrogen is extracted in the water phase. L-arginine was identified as free amino acid in the hydrolyzate, the remaining fraction of the proteinaceous material extracted is in the form of small water soluble peptides. In this study the experimental conditions (temperature and residence time) are optimized to maximize the L-arginine yield. The hydrolysis process and the reaction kinetics are described by a reaction model. The rate constants of the hydrolytic conversion were determined for the resulting products (L-arginine and peptides).

Kinetics of arginine and soluble peptides production from microalgae using flash hydrolysis

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.