Paper details

Title:

Optimization of the Algae Production in Innovative Ponds - The MAMBO Project

Author(s):

Prussi, M., Chiaramonti, D., Casini, D., Rodolfi, L., Bassi, N., Bacci, F., Bondioli, P., Della Bella, L., Rivolta, G., Chini Zittelli, G., Tredici, M.R.

Document(s):

Abstract:

Production of microalgae biomass as an alternative feedstock for biodiesel is a promising technology. The reduction in energy consumption of traditional algae cultivation systems is today one of the most important issues towards sustainable biofuel production. In the MAMBO project an innovative pond has been designed and realized to investigate the possibility of reducing energy consumption of the cultivation phase as well as the use of water. The aim of this project is in fact to demonstrate the possibility of using algae as an alternative and cost­effective feedstock for the biodiesel industry. The innovation is based on the reduction of the mean fluid velocity in the pond and the reduction of the water head, while maintaining sufficient turbulence and recirculation of the culture. The typical energy demand for mixing in a traditional raceway pond, operated at 20 cm depth and 20 cm/s speed, is estimated in 0.034 W/m2. The reduction in fluid velocity has a large impact on the energy demand of the cultivation phase (essential in view of biofuel production), nevertheless the major drawback is that it also reduces the effectiveness of mixing, which is a key factor to obtain high productivity per unit area. A reduced culture depth also offers the advantage of a lower amount of water needed per square meter of pond maintaining the same area for solar energy input and leads to higher algae concentration in the fluid medium. Injection and solubilisation of carbon dioxide in the fluid stream also deserve attention. Systems have been developed in the innovative pond to avoid or reduce uneconomical CO2 losses. The real flow field in both the traditional and the innovative ponds was evaluated by velocimetry measurement under actual operation conditions. The methodology adopted in this research work was based on a combination of numerical and experimental activities. A numerical tool was designed to estimate the effect of the reduction in fluid velocity and culture depth on energy consumption and mixing. The results obtained from numerical simulations were then used in designing the innovative pond and defining the main operational parameters and characteristics. Tests on the traditional raceway pond and on the innovative one were carried out during summer 2010 in Florence (Italy). The on­field collected data were elaborated linking microalgae productivity to solar input and energy consumption. The preliminary results obtained during the first year of experimentation showed that the innovative pond has a slightly lower productivity compared to the traditional pond, but needs significantly less energy and water. The solutions tested in this research is already interesting in all the country where water is a precious resource and land is often not yet profitably used.

Keywords:

algae, biodiesel, microalgae, vegetable oil

Topic:

Biomass Resources

Subtopic:

Microalgae production and conversion

Event:

19th European Biomass Conference and Exhibition

Session:

OB7.1

Pages:

90 - 93

ISBN-13:

978-88-89407-55-4

ISBN-10:

88-89407-55-7

Paper DOI:

10.5071/19thEUBCE2011-OB7.1

Price:

FREE