Online Raman Monitoring of the Algo-production in photobioreactor – ORAMA

Microalgae are interesting renewable energy source with attractive industrial properties. To be aware of the production progress, several approaches can be applied to measure their production. Nevertheless, the current analyzes are limited to a monoparametric approach that often destroys the cells and makes impossible the online control of the process hence the advantage of using non-invasive methods such as spectroscopic methods. The ORAMA project aims to explore the ability of the Raman spectroscopy to control the algal production process by interviewing the physiology of algal cell directly in-situ. This sensor could providing a reliable response in real time of the algal cells composition in order to improve the harvest time and to alert the operator in the case of unexpected problems with regard to maintain an optimal performance of his process. Microalgae are interesting source of raw materials with very interesting industrial properties (fuel production, biomass, high value molecules, etc.). Often, the monitoring of the production of these molecules is performed by monoparametric methods relatively simple which allow the evaluation of certain physical parameters (pH, T, turbidity, gas).To improve the understanding of the bioprocess, the characterization of the produced molecules is performed by high-performance analytical methods. Nevertheless, the analysis requires the destruction of the cells followed by extraction with organic solvents. These off-line techniques make it difficult to control rapidly the process, hence the advantage of using non-invasive methods such as Raman spectroscopy which would potentially allow in-situ study of cellular physiology. The ORAMA project proposes taking into account the entire measurement and value chain, ranging from the design of the measurement system to its test under industrial conditions and its commercialization. The developed sensor would provide a reliable and real-time response to algae composition, helping to better manage the crop and alert the operator to unexpected complications in the process. Several on-line analysis strategies are envisaged in our project to find the best results in terms of performance and practicality. The challenge is to adapt the analytical system to be able to evaluate directly the content of the algal cell by optimizing the technical parameters necessary for the direct monitoring in the very complex medium. Technological and scientific challenges are connected to the development of a robust database, the impact of the culture medium on the algae cell's own footprint, the low sensitivity of the measurement system and the fluctuation of signal due to the mobility of the studied cells. These locks are minimized by the design of optimized optical reader and suited statistical models. Other scientific questions such as the formation of biofilm on measuring surfaces and their impact on the production will be dealt in order to understand this complex problem common in bioprocesses. Our project offers a strong consideration of industrial constraint by combining both a pre-industrial platform and a companie (end user) to test the developed method. The final phase consists of validating the developed technology on closed raceways of an algal production platform. The prototype will be deployed in the installations of the end-user to validate its suitability with the fixed objectives (TRL 7-8). In parallel of technological developments and scientific research phases, a market research will be carried out to identify the sectors of potential application of the developed technology and to promote this new technology in other fields of bioprocess applied in the food or medical sectors.