Continuous aqueous two-phase extraction of microalgal C-phycocyanin using a coiled flow inverter

In this study, the intensification of C-phycocyanin protein extraction from the green microalgae Spirulina maxima was successfully achieved using aqueous two-phase systems coupled to different continuous-operation extractors. Three systems with different total concentrations of Polyethylene glycol and potassium phosphate salt were tested in three different types of continuous systems: a conventional straight-tube extractor, a helical-coiled extractor, and a coiled flow inverter extractor. Results showed that the coiled flow inverter extractor achieves higher overall performance than the other continuous extractors at the same flow rate and same residence time for all the concentrations tested. Similarly, all the continuous-operation extractors showed higher extraction performance than a batch-operation extractor for similar times tested. It was observed that extraction performance in the coiled flow inverter increases as flow rate increases (coefficient of partition increases 1.74 fold by increasing the flow rate from 10 mL/min to 30 mL/min). The C-phycocyanin extraction in this continuous system was benefited from a decrease in the extraction time with high Dean numbers.