Evodos improves algae harvesting system
Evodos BV, an algae technology developer based in Netherlands, believes the company’s spiral plate centrifuge created for the harvesting of algae will give algae harvesting a positive energy balance. Tests show that the centrifugal system can run below 1 kWh per cubic meter, costing roughly €0.08 per kilo of dry material produced. Marco Brocken, CEO of Evodos, said that the results achieved by Evodos’ harvesting unit help to show that the industry can produce algae-based fuel at scale.
The core of the technology is based on improvements to the centrifugal system including separation efficiency that the company explains is related to the short distance a particle has to travel in the unit, the extended delay time that particle has to travel and the use of a Y-flow approach, which has no counter flows within the centrifuge. To separate the algal biomass in the unit from the water, the biomass is spun in the unit and the collected particles settle into a spiral rack, which forms a solid cake. When the solid cake becomes too thick, the ends of the spiral plates are removed and a sliding drum containing the spiral plates and the solid biomass is pulled upwards, out of the unit for the removal of the cake. Evodos believes its system performs well due to the fact that before discharging the cake, any free liquid is removed.
In addition, the company noted five areas where the system shows positive benefits for the user. The first relates to the maintenance required for the system. According to the company, “the root cause…for using only a minimum of energy” is based on the low requirement of 3.000G to separate the fines. “The low G-force leads to [fewer] vibrations,” which, the company said, “has a huge positive effect on maintenance costs.”
In addition to the low costs of maintaining the unit, the company also pointed out the low noise created by the system (due to less rotations per minute), the small number of infrastructure requirements needed for the system all with the ability of the machine to help with the sequestration of carbon dioxide (CO2) and fuel production. MBD Energy based in Australia has already started using the Evodos centrifugal harvesting system for its own algae-CO2 sequestration project. The technology can be used for wastewater treatment, manure treatment, flour and starch clarification and a number of other purposes.