FPA Photobioreactor

Functionality of the Subitec flat panel airlift-photobioreactor

The patented Subitec cultivation technology is based on a uniquely designed flat plate reactor. The unique reactor technology avoids disadvantages of photobioreactors with conventional design. The systematic technology advaces a range of benefits, whereas outstanding is the patented stream guidance induced by integrated static mixers marking the key for the success of the FPA-reactor.


  • Optimal light distribution to all cells by stream guidance induced by static mixers.
  • Complete intermixing and homogenization avoiding photo-oxidative stress and improving efficiency of cultivation, especially at high light intensity.
  • Photoinhibition constrains photosynthesis in other systems.
  • Minimal shear-stress on algae.
  • Simple temperature and pH control, efficient gas transfer.
  • Higher cell densities compared to other systems. 
  • Reduction of turbulence at low light intensities.
  • Pulse-aeration during nighttime to prevent cell sedimentation.
  • A photovoltaic plant can be integrated as an ideal sour-ce of energy supply for a microalgae production plant.
  • Flexible scalability of production capacities due to modular construction.

Light distribution is essential

The cross-section of every photobioreactor, regardless of its design, can be intersected into three zones of diverging light intensity. Directly at the surface light intensity is so high that photosynthesis can hardly take place (photoinhibition). This section is followed by a thin division of optimal light intensity. In the deepest zone, self-shading of the culture leads to light limitation.

The FPA reactor operates by following the principle of an airlift-loop-reactor and achieves an optimal light supply of all microalgal cells due to the small layer thickness and the stream guidance induced by static mixers. The key is the directed transport of cells enforced by the incorpor-ation of static mixers. Refracted rising gas bubbles transfer the culture medium into a stationary, circular flow. Herewith, all microalgal cells are transported from and away the illuminated reactor surface area in an inter-val of about 1 Hertz. By varying the distance between FPA-reactors at outdoor cultivations, average light intensity on the reactors may be altered.


                                                                                                                          Even light input into Subitec's FPA-reactor.


                                                                                                                          Large reactor surface with controlled light guidance.


                                                      Construction in two trans-parent plastic half-shells.