Experimental plant for the cultivation of microalgae in photobioreactors for energy production

The continuous research of alternative and sustainable energy solutions with respect to fuels deriving from oil has led the current industrial and scientific system to analyze and develop approaches and technologies capable of enhancing materials of different nature for the production of biofuels. Algae are an alternative widely studied for this purpose, not only respect to the production of fossil fuels, but also respect to first-generation biofuels that use higher plants produced by normal cultivation methods. There are many plant solutions tested and disseminated internationally, operating in both outdoor and indoor environments. One of the most widespread criticisms is the inability to supply biodiesel quantities suitable for a production scale and with a positive economic and energy balance. This paper describes the results of a 4-years experimental research project oriented to the development of a low-scale demonstration plant of a complete advanced energy system based on the massive cultivation of microalgae and their treatment aimed at competitive production and sustainable bio-oil and biogas having requisites of suitability and compatibility with the relevant reference markets. The article intends to focus on a specific technological macro-component, completely studied and realized during the research project: the transparent, fully closed tubular photobioreactor (PBR) made of plastic material operating in continuous and in outdoor environments used for algal cultivation at low cost and high efficiency. The experimental plant was developed with the aim of providing a contribution to the main critical situations spread in this field, in particular: the need to reduce costs of the components of the plant and of the input resources necessary for the functioning of the system (energy, fertilizers, CO2, water, etc), as well as to maximize its modularity, reproducibility and exportability in other territorial contexts.