Microalgae

microalgues

The COLDEP system can significantly improve the performance of microalgae culture in raceways:

  • Water circulation at low energy cost
  • O2 stripping, thus removing the productivity inhibition normally induced
  • Harvesting microalgae without damaging their cell structure and concentrating up to 100x

 

Microalgae culture

A COLDEP system allows to :

  • Circulate water in a raceway with an energy cost of 5W/m3 of water displaced
  • Generate flows between 10 and 500 m3/h, enough for 100m2 basins and even more
  • Regulate O2 level in water at 6-7 mg/L when it rises up to 40mg/L without stripping
  • Recarbonate the medium by injecting CO2 and ensuring complete dissolution along the entire height of the column
  • Maintain the acidity of the medium (pH<7) throughout time when it often rises above 8 without regulation
 raceway 

 

recolte

Harvest and concentration

The improved performances of the flottation mecanism, due to the water height, allow to :

  • Harvest microalgae in concentrations from 2 to 5 g/L in culture ranging between 0.01 g/L and 0.2 g/L
  • Reach concentrations up to 20 g/L by self-flocculation (within minutes)
  • Achieve energy efficiency of 1kW.h/kg of dry matter extracted

It's an efficient way to pre-concentrate a culture of microalgae before a centrifugation step for example.

These results were obtained with diatom algae (navicula directa), with Nannochloropsis and with scenesdesmus. Furthermore, Dunaliella salina is collected at a concentration of 80g / L each day with a COLDEP system.