Pilot-scale biofuel production from sunflower crops in central Italy

Abstract

A pilot-scale trial of oil and biodiesel production from high-oleic sunflower was performed in Tuscany (central Italy). An experimental investigation was carried out to evaluate the field performance and the product properties and yields of two high-oleic hybrids (PR64 H31 and PR65 H41). The processing facility, a pilot plant with a limited production capacity located in the proximity of the production field, included a platform for oil production and transesterification. The oil yields of the two high-oleic varieties were around 35% with respect to seed weight. The sunflower seed oils obtained fulfilled most of the quality requirements for the use of vegetable oils as engine fuels. The production of biodiesel was carried out in the transesterification unit. However, the production and the direct use of the sunflower seed oil seemed to be a more suitable option than its conversion to biodiesel, especially at a small scale like that considered in this study. The possible exploitation of seed pressing co-product (sunflower cake) as solid biofuel was assessed. The relatively high calorific value (21 MJ kg−1) and the low moisture content (<15%) made it an interesting option for thermal applications. Field and process data allowed the evaluation of key performance indicators for the production chain. Biofuel and bioenergy yields as high as 1850 and 3170 kg ha−1 and 68.7 and 59.6 GJ ha−1 were obtained for oil and cake, respectively. Based on these data, different scenarios of fuel and energy production in the rural context of Tuscany were hypothesized.