Intensifying extraction of biomolecules from macroalgae using vortex based hydrodynamic cavitation device

 Macroalgae have a tremendous potential to become an important renewable resource for valuable biomolecules  and chemicals. New and improved ways of cell disruption and of enhancing rate as well as yield of extraction of  valuable products from macroalgae are needed to fully realise this potential. In this work, hydrodynamic cavitation (HC) was used for intensifying rate and yield of extraction of phycoerythrin, proteins and carbohydrates  from marine macroalgae Palmaria palmata. We use vortex-based HC devices which do not use small restrictions  like orifice-based HC devices or moving parts like rotor–stator based HC devices. A bench scale setup with a  nominal slurry flow rate of 20 LPM was established. Dried and powdered macroalgae was used. Influence of key  operating parameters like pressure drop and number of passes on extraction performance (the rate and yield) was  measured. A simple, yet effective model was developed and used for interpreting and describing experimental  data. The results indicate that there exists an optimum pressure drop across the device at which extraction  performance is maximum. The extraction performance with HC was found to be significantly better than the  stirred vessels. HC has resulted in 2 to 20 times improvement in the rate of extraction of phycoerythrin (R-PE),  proteins and carbohydrates. Based on the results obtained in this work, pressure drop of 200 kPa and number of  passes through the HC devices of about 100 were found to be most effective for HC-assisted intensified extraction  from macroalgae. The presented results and model will be useful for harnessing vortex-based HC devices for  intensifying the extraction of valuable products from macroalgae.