ÖkoPro integrates algae and aquatic biomass production into agricultural processes (e.g. by surface water treatment for biogas plants).
ÖkoPro focuses on reusing residues from biogas plants (and other surface waters) and their subsequent use to further optimize agricultural production efficiency per area. The project thus adresses problematic residues of standard processes in biogas plants which are yet unsolved.
In the project, different promising microalgae systems are tested, process parameters are evaluated and targeted aquatic biomasses are analyzed with respect to important parameters. Possible and worthy of testing here are especially productions for petfood and cosmetics.
Decentrally occurring nutrients, CO2 and heat surpluses are reused directly and sensibly.
Constant quality control is ensured by a toxicologically constantly monitored (micro) algae production.
Biogas plants produce liquid streams from silage pits and other surface water (roofs, roads, etc.) that are sometimes highly contaminated. As part of the project, B.E.S. is developing a method for recycling low-contamination water (approx. 12,000-16,000 m³ per year) using algae biomass. The contamination of the water with particles can be estimated based on its conductivity and turbidity. Two pumps installed in a seepage water shaft are used to start one pump when conductivity/turbidity is high, and the water is fed to the adjacent biogas plant. This ensures that this wastewater stream is used to generate energy. The second pump, which is only activated when conductivity/turbidity falls below a certain level (to be defined during the course of the project after analysis), pumps the lightly contaminated water into the equalization tank that was built as part of the project. In addition, various condensate wastewater streams (condensate from gas pipes, condensate from seepage water stripping) are quantitatively fed into this water stream after analysis. To supplement the process described above, CO2 from the flue gas of the CHP plant will be fed into the reactor to optimize algae production. B.E.S. has set up all these infrastructures and implemented them in intelligent control systems.
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Microalgae are plant-like organisms and highly diverse in their properties. Unlike us, they are able to produce the so-called essential amino acids that non-photosynthetic organisms need to live. They are also full of unsaturated fatty acids that improve our vital functions. Microalgae can be cultivated in pure culture, i.e., as a monoculture, or as a mix, which greatly increases the culture's adaptability to fluctuating conditions. Depending on the starting medium and the type of biomass reuse, either a pure or a mixed culture may be appropriate. Both have been tested for ÖkoPro.
Microalgae are an attractive ingredient for animal feed due to their sustainability and excellent nutrient profile. Microganic trades in microalgae-based feed raw materials. As part of the ÖkoPro project, microalgae from regional cultivation in surface water from biogas plants were tested for their suitability as animal feed. The project is investigating whether these microalgae meet the usual safety requirements for animal feed. It is also examining the extent to which these microalgae may have special characteristics in terms of their ingredients and digestibility compared to other microalgae available on the market, and whether any advantages can then be specifically exploited in marketing as pet food.
Biogas is considered a building block of the energy transition, but it also presents challenges. Every year, tens of thousands of liters of nutrient-enriched surface water are generated at biogas plants, which may not simply be returned to the environment. The ÖkoPro project shows how this can become an opportunity for more sustainability: Microalgae are the key.
The aim was to use surface water and other material flows from biogas plants for the production of usable microalgae biomass, and at the same time to clean the water. A concept with double benefit: Environmental protection meets value creation.
On the grounds of a biogas plant near Bad Bentheim, a reactor-based algae system was set up. An intelligent control system separates weakly and heavily polluted surface water, and directs only suitable amounts into the new algae basin. In addition, CO₂ from the combined heat and power plant as well as excess heat are fed in to promote the growth of the microalgae.
The result: The algae remove nitrogen, phosphorus and CO₂ from the water, thereby improving water quality, and at the same time valuable biomass is created.
The possible uses are diverse:
Feed: Microalgae from the reactor were successfully tested for their usability as animal feed. Their ingredients, including essential amino acids and unsaturated fatty acids, make them particularly interesting for pet food products.
Cosmetics: The partner company oceanBASIS tested extracts from the algae for natural cosmetics, with antioxidant effects and positive effects on skin moisture and elasticity. The challenge: The biomass obtained in the project was not consistent enough to economically meet the strict EU cosmetics requirements.
Patches & care products: Based on the extracts, innovative cosmetic patches made from alginate were developed, which continuously release active ingredients through the skin, with prototypes that performed promisingly in dermatological testing.
ÖkoPro proves: Microalgae are more than dietary supplements. In combination with biogas plants, they can bind problematic material flows, relieve the environment, and at the same time produce products with real market potential. Especially decentralized agricultural businesses could thus take new paths to keep nutrients in circulation, actively use CO₂ and increase their efficiency.
Project coordination: Sascha Hermus, M. Sc. Biology
