Clarification of low concentrated microalgae suspensions by decanter centrifuge

M.C. Quesada Salas, E. Clavijo Rivera*, G. Willig, F. Allais, AgroParisTech, France

Microalgae biorefineries require the development of efficient processes for an economic viable production of microalgae products. After culture, cells are harvested and disrupted to facilitate extraction and separation of high valuable compounds. In order to recover soluble compounds such as sugars and proteins, the liquid phase needs to be separated from cell fragments through a solid-liquid separation stage. Decanter centrifuge may be employed in microalgae biorefineries for both, harvesting and clarification of the liquid phase after cell disruption. Compared to other type of centrifuges, decanter centrifuges produce cakes with a higher level of dryness (up to 40% dw) and can be operated in a continuous mode. However the low concentration of microalgae cultures makes the solid-liquid separation process much more challenging.

This work aims to study the solid-liquid separation of microalgae suspensions by the use of a decanter centrifuge (Lemitech MD 80-Sn). Several suspensions of microalgae at 10 g/L dw were fed into the decanter using a peristaltic pump at flow rates ranging between 10 and 20 L/h. Centrifugal acceleration varied from 1000g to 4000g and differential speed (between the bowl and the scroll of the decanter) ranged from 5 to 200 rpm. The level of clarification of the supernatant and the dryness of the solid phase were evaluated by the measurement of total suspended solids (TSS) and dry matter of both phases for all studied conditions. Results showed...

Session: L10 - Centrifugal Sedimentation - Decanter Centrifuges
Day: 23 October 2019
Time: 16:45 - 18:00 h

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