Processes and Technology

  • Harvesting refers to the separation of the biomass from the growing medium and concentration of the diluted algae suspension until a thick algae paste is obtained.
    This is a two-step process, which involves harvesting and dewatering. Harvesting microalgae is difficult, due to the small size of the algea. However, the triangular shape of the HAVPTM enables harvesting simply by using flocculation and gravitation. This dramatically simplifies harvesting of the microalgae, reducing costs and energy requirements.
    UniVerve developed a unique flocculent that doesn’t contain aluminum. The flocculent is used to sediment the biomass as preparation to easy harvesting with a simple pump, instead of using the traditional centrifuge, which is expensive and requires a lot of energy. This allows for lower energy consumption as well as the implementation of batch production instead of the traditional continuous production (less contamination risk and higher yield & oil content).

    In-situ flocculation. Side (left) and top (right) view of a flocculation process within a 3 m HAVP. 

    The biomass is concentrated at the bottom of the HAVPTM and pumped out.
    Then, the biomass is transferred into special geo-textile bags for dewatering.
    First the solid concentration is brought down to 10-15% and afterward to 25% and up.

                      Stage 1                                                        Stage 2

    UniVerve demonstration site's settlements tanks and the biomass dewatering work area.