Practice Abstract - Research and innovation
Sustainable solutions for the industrial production of microalgae biomass: indirect hybrid solar dryer and off-the-grid tubular photobioreactor
Microalgae cultivation and drying costs are still high, mainly due to the considerable energy consumption. In an effort to reduce biomass costs and improve sustainability, ProFuture partner Necton implemented two innovations at industrial scale.
The first was an indirect hybrid solar dryer, an equipment never used before to dry single cell microalgae at industrial scale. This drying method was compared to the standard freeze drying via assessment of biomass quality parameters. No significant differences were found between the applied drying technologies for total proteins, carbohydrates, lipids, and fatty acid profiles. On the other hand, some pigments showed significant differences, displaying up to 44.5% lower contents in solar-dried samples. Finally, analyses of microbial safety and functional properties of the solar-dried biomass showed suitability for food and feed products.
The second innovation was an off-the-grid tubular photobioreactor (PBR). The 27 m3 flow-through glass PBR, is able to work only with photovoltaics energy, thus greatly reducing operation costs. The pumps work at the maximum speed when enough sun is available, but slow down when the photovoltaic production reduces, and turn off before sunset. This behaviour fits the mixing needs of the microalgae cultures, because it is during high sun incidence that the cultures need to have an efficient gas-exchange (CO2 injection and O2 removal), while during the night the mixing needs are expected to be much lower. To access the quality and behaviour of microalgae cultures in this PBR, one cultivation cycle of Nannochloropsis oceanica was followed. Growth, fluorimetry and microbiological analysis showed no detrimental effect of the off-the-grid regime. Nevertheless, the culture only lasted for 6 weeks, which can be considered short for N. oceanica. Further studies are needed to access the quality of the cultures under an off-the-grid regime.
Source Project
Ongoing | 2019-2023
ProFuture
Ongoing | 2019-2023
- Main funding source
- Horizon 2020 (EU Research and Innovation Programme)
- Geographical location
- Spain