Algae need carbon dioxide and nutrients as well as a lot of (solar) light to grow. They find ideal conditions in photobioreactors. After a construction period of only 11 months, algae manufacturer ecoduna AG started production in January in a giant greenhouse in Bruck an der Leitha in Austria. The large-scale plant of the former start-up consists of around 43,000 glass tubes arranged vertically on an area of around 10,000 square meters. “The largest photobioreactor plant for the cultivation of microalgae in Europe, with a volume of 780 cubic meters, got off to a good start despite initially low outside temperatures and limited light availability, six months after commissioning,” explains biologist Dr. Silvia Fluch, Chief Operating Officer at ecoduna.

The plant was already in full operation with 32 photobioreactors by mid-March; daily maximum harvests of 160 kilograms of dry biomass were achieved. The advantage of the closed systems and the high degree of automation is that undesirable contamination is largely ruled out. The early summer allowed for a relatively early switch to the summer algae Spirulina, whose production started in May. Dr. Fluch explains: “The simple switch to a new algae species and high productivity figures for the early summer months demonstrate the practicability of glass for the implementation of a large-scale plant. The extremely high outside temperatures in the summer posed a challenge for the algae cultures, which could however be mastered without any problems.”

On the one hand, the newly constructed plant proved that glass is a material excellently suited for use in photobioreactor construction due to its properties, such as mechanical stability and light transmission. On the other hand, the previously existing length restriction for horizontal tube systems does not apply to the vertical arrangement of the tubes. “With the new vertical design, the photobioreactor technology can be adapted to the respective local conditions. There is no longer any restriction on the length of a PBR,” explains the biologist.

There is great interest in the new PBR technology from the international trade public. The responsible persons at ecoduna were also able to experience this during the visit of a 50-member delegation during the European Algae Summit in Vienna. In expert circles, ecoduna technology is regarded as a valid alternative to other PBR systems with the advantage that glass is easier to clean and therefore the technology is more environmentally friendly than other systems in the long term. ecoduna cultivates algae strains such as Chlorella in the winter and Spirulina in the summer. Both serve the dietary supplement market, with Spirulina scoring points for its high micronutrient and antioxidant content. ecoduna was able to place the products well at the Vitafoods trade fair in Geneva, the largest trade fair for food supplements. In addition to the high quality of ecoduna biomass, Omega3 oil (EPA) was the focus of customer interest.

The annual production of one hectare will by no means suffice to meet the demand signaled to ecoduna by B2B customers. In order to take this into account, ecoduna is planning to expand its capacity by another two hectares. To implement this project, a capital increase in the form of a share issue will be launched in September 2018. At the same time, the subsidiary eparella GmbH has started to offer high-quality spirulina powder in vegan capsule casings for end consumers as well.

• More about photobioreactors
• Website ecoduna
• Which algae cultivation system is best for you?

• Ecoduna case story: Higher productivity

• More efficiency with high end glass PBRs

• Algae cultivation: Plastic tubes or tubular glass?