15 14 Algae growth, day and night 3D printing with biomass Respiration under control Intelligent sensor technologies Quantum sensors for optimised resolution Soft sensors combine data Thanks to automation, the bacteria cultures can grow under ideal conditions around the clock. The continuous collection and monitoring of measurement data ensures the high quality not only of the algae growth itself, but also of the basic substances the algae produce when nutrients are added. The experts from Festo have been giving particular attention to the vegetable chlorella alga and the blue-green alga Synechocystis, a species of cyanobacteria. Chlo- rella is used as a food supplement and in the production of cosmetics; Synechocystis also produces colour pigments, omega-3 fatty acids and beads of PHB (polyhydroxybutyric acid) for bioplastics. The yield of these algae species in the automated PhotoBionicCell from Festo surpasses that of systems commonly used today, which are designed as open basins or foil bioreactors, by a factor of about ten. The PHB beads from the PhotoBionicCell can be processed into a filament for 3D printing by the addition of other substances. With this modern production technology, sustainable plastic components or packaging with complex shapes – and connecting elements for the photo-bioreactor from Festo – can be produced within a short time. The 3D-printed elements are recyclable and environmentally degradable in a closed cycle. Even the incineration of PHB-based plastic bottles does not release any more carbon dioxide than was previously bound from the ambient air. No fossil resources are required in the production of bioplastics. Photo-bioreactors throughout all continents are to produce biomass in large quantities in future, in exceptional quality. They should consume only a minimum of resources, while binding as much carbon dioxide as possible from the ambient air – a complex task, which requires many factors to be optimised at once. The experts are meeting this challenge with their many years of competence in control and regulation technology, with state-of- the-art components from microfluidics and LifeTech and, last but not least, with expertise in artificial intelligence. The PhotoBionicCell reactor system must be able to automatically provide for its bacterial cultures. A flawlessly functioning respiration cycle is essential, since algae are living organisms with a permanent metabolism. With a holistic gassing strategy, the development experts are ensuring that the carbon dioxide extracted from the air is evenly distributed within the circulating biofluid. An innovative, material- optimised ceramic element from Festo with minute pores already enables introduction of the gas in the form of fine bubbles. To be able to provide the best possible growth and living conditions for the microorganisms, sensors must provide the right information – constantly and, above all, in real time. Only then is it possible to react to process events immediately and to regulate accordingly. In combination with classic sensor technology, the innovative technologies employed in the PhotoBionicCell by the experts from Festo literally make for quantum leaps in automation. A new type of sensor based on quantum technology provides precise infor- mation about the growth of the bacteria culture. The algae are automatically and continuously introduced into it in microfluidic dilution. The quantum sensor is able to detect individual cells by means of a laser beam, so that the quantity of biomass in the PhotoBionicCell can be determined. It also examines the cells for their state of health. It provides four times as many measurement values as was possible with sensors previously used. The experts are expecting even more in the future: the new quantum sensors are opening up an unimaginable dimension of spatial resolution and sensitivity. Another option is to use the intelligent soft sensor from Festo instead of quantum technology. This is a kind of virtual sensor that is implemented in the programmable logic controller in the control cabinet. All the information from the bioreactor and its surroundings is brought together here, along with the data streams from the classic sensors – temperature, nutrient supply, carbon dioxide content, pressure, reactor filling level and pH value. Algorithms process the signals received and instantly compute the missing variables, such as the overall quantity of microalgae or the basic substances they produce. On this basis, the actuators come into operation and the entire system is thus controlled. The integration of soft sensors makes it possible to deduce difficult-to-measure conditions within the process on the basis of existing measurement signals. With automated and energy-optimised bioreactors such as the PhotoBionicCell from Festo, the efficiency of algae can be increased by a factor of ten. Algae are already efficient in nature and bind ten times more carbon dioxide than land plants in the production of biomass.
RkJQdWJsaXNoZXIy NzczNDE0