The BioFence™ is a highly efficient and reliable method for producing high density monocultures of marine and freshwater algae. It typically operates at twicethe density of conventional cultures and is highly productive relative to conventional methods. The innovative manifold design dramatically reduces labour requirements and eliminates handling problems. The system can be operated for prolonged periods without culture crashing, which is facilitated by a patented tube self-cleaning mechanism. It is a closed, controlled system, where environmental parameters are automatically controlled. Importantly, the system is easily expanded to meet increased production requirements.
The BioFence™ works by recirculating algae, nutrients, water and carbon dioxide through transparent tubes to maximise the amount of light reaching the algal cells. The short light path maximises this process, thereby enhancing photosynthetic efficiency. A reservoir tank provides a dark phase for the complex protein building functions within the algal cells. The system is supplied by a semi-continuous stream of sterilised water, nutrients, and CO2; which are all supplied to the dark phase of the process. This function is fully automated and regulated via the process control system. Live algae are collected into a receiving tank via an overflow. The output volume is equal to the process input volume, typically 20 to 30% of the system’s volume per 24hrs. A centrifugal pump with recessed impeller and variable speed control circulates the algae and nutrients around the system. The combination of variable speed control ensures variable shear rate and optimal cell viability.
The BioFence™ system can offer the appropriate level of environmental control for any production process, and is proven to grow over 30 commercial species. The modular construction of the BioFence™ and configuration of arrays means that the system can be constructed to meet site specific requirements. Tube diameter and manifold sizes can be made to measure. Systems can be hybridised with open ponds or pre-existing primary production systems.