Evaluation of Posidonia oceanica waste as a biomass source for energy generation

Abstract

The use of Posidonia oceanica (PO) waste biomass for energy production is under consideration in several countries of the Mediterranean region. The aim of this paper is an evaluation of using PO waste as a biomass source for direct combustion in territorial contexts where the presence of large quantities of beached seagrass is a problem for the tourism-orientated economy such as Istrian peninsula in Croatia. The presence of large PO leaves deposits on the Istrian beaches is responsible for some negative inconveniences, such as the odor released during the natural degradation processes. Other problems are connected with the visible appearance of the beach and negative connotation of PO with pollution of the touristic area. This condition reduces the possibility of touristic competitiveness of the hotels, apartments, bars, and restaurants that are located along the seaside promenade or beaches covered with PO biomass. This paper shows data of PO waste properties as a resource for energy generation which can help to decrease costs of their collection and could improve the quality of life of residents and tourists in the nearby areas. From energy properties, the heating values of fresh and dried onshore biomass samples of PO biomass were within the range of main agricultural and forest biomass and it was around 9–11 MJ/kg; ash content is very high (16–36%) compared with other types of biomass. Due to the abovementioned data, PO waste carries some inherent limitations to its use as biomass in direct combustion and energy generation, primarily due to high ash content. Furthermore, PO waste can be recognized as a potential fuel for combustion or co-combustion due to its low sulphur (1.15–2.36%) and nitrogen (1.47–2.39%) content but the low carbon content (25–32%) is not a favorable characteristic. It can be concluded that PO waste is a potentially interesting source for energy production.