Pilot plant system for biodiesel and pellet production from cardoon: technical and economic feasibility

Cardoon (Cynara cardunculus L.) is an important species as biomass and oilseed production. It is well adapted to grow with low input management in the Mediterranean environment. The study is related to use the biomass and grain production for energetic purpose. The research was carried out in a 3-years period from 2010 to 2012 in different internal areas of Sicily. The plant material for this research was collected in various experimental fields, for a total area of 10,000 m2. Biomass and grain processing was performed into two different pilot systems for biodiesel and pellet productions. In the three years, regards to the total biomass production, a total yield of 64 t ha-1 of pellets was obtained. While a 23.3% of oil was extracted from grains through cold pressing and transesterified with a production of 985 L of biodiesel. The total residual presscake was 3.03 t, and it has a composition of 21.3% of protein and 6.9% of oil, which represents the 5.3% of total seed oil content. This characteristic confirms the possibility to use cardoon residuals presscake as feed. Economic balance of the process was performed to determine the economic suitability. The results show that using biomass and grain for different energetic purposes, make cardoon a very competitive and sustainable energy crop in Mediterranean environment and it represents an economic valid alternative for farmers.