Assessment of the Performance and of the Profitability of CHP Energy Systems Fed by Vegetable Oils

In this paper, energy and economic analyses of vegetable oil fed energy systems are presented. The paper focuses on the process from oil to energy, while the economic costs of the transformation process of the biomass from field to oil is assumed embodied in the cost of the oils. Five different oils are considered (sunflower, rapeseed, soybean, palm and waste fried oil) as fuels for cogenerative Internal Combustion Engines, also running in combined cycle configuration. In particular, the considered combined cycle is composed of Internal Combustion Engines and Organic Rankine Cycle modules. Energy analyses allow the evaluation of the installed power, of the produced energies, and of the primary energy saving index for different yearly oil mass values. The results of the economic analyses as a function of yearly oil mass are also presented. The cost sources are highlighted in order to point out the major contributors. Moreover, analyses of the limit value of incentive and oil price, in order to guarantee plant profitability, are carried out.