Description
Emissions of CO2 have profound effects on the global climate, demonstrating the importance of carbon capturing and sequestering (CCS) to limit its release and other greenhouse gases (GHG) into the atmosphere. Current CCS methods are either relatively costly or use so much energy that the mitigation benefits become marginal. Microalgae have the ability to fix CO2 using solar energy with high efficiency and also to use other GHG as nutrients. However, a number of crucial research gaps remain that must be overcome to achieve full-scale operation including optimization of existing photobioreactors (PBR). The FLEXIPHO project aims to design a flexible PBR, optimize for microalgae culture, to capture GHG in areas of low solar irradiance. The outcome will be a new bioreactor sustainable and flexible and microalgae biomass (Nannochloropsis gaditana and Haematococcus pluvialis) convertible into useful industrial products (omega-3 fatty acid and astaxanthin, respectively), creating economical revenues and bringing added value to the CCS process. The partnership will result in a flow of technological knowledge and experiences, contributing to the results proposed.
Summary of project results
The FLEXIPHO project focused on the conceptual engineering design of a photobioreactor (PBR) that can be used in areas or periods of the year of low solar radiation that are not currently suitable for the cultivation of microalgae. This PBR is designed to minimize its contribution to the total cost of the production of microalgae valuable products. To achieve this, besides working in an innovative geometry of the facility, we have integrated a solar reflector to increase low-light radiation. The solar reflector is used to collect the fraction of sunlight not directly absorbed by the PBR and through reflective surfaces, directing it to the PBR and thus increasing the incident solar radiation. Also, a treatment and capture system of industrial gases is defined to lower the high production costs of microalgae biomass. In this way this waste stream is used as a source of CO2, that is critical for photosynthesis and thus for the growth of microalgae. Then, commercial CO2 costs are avoided. The system has been validated at laboratory scale demonstrating the improvement of microalgae subjected to low light irradiation, when using a light concentrator compared to a PBR control. The cultivation of the species Nannochloropsis gaditana has been used as a study model and it has been demonstrated that using a concentrator the accumulation of biomass and daily productivity are improved by more than 40%. It has been shown experimentally that CO2 is an important source of feed as long as the optimum pH range is controlled for each species and gas feed is adapted to this parameter
Summary of bilateral results