Abstract
The growing world demand for energy and the need to limit the level of polluting emissions requires to push the exploitation of renewable energy sources, such as solar, wind and hydraulic energy and the use of alternative fuels that are more attractive from an environmental point of view and limit the production of pollutants such as Sulphur oxides, nitrogen oxides and carbon dioxide. A further contribution can be obtained with a better exploitation of the primary energy content of fuels. Adopting Combined Heat and Power (CHP) solutions makes it possible to generate both electrical and thermal power with a higher overall efficiency and a better use of the primary source. The use of small widespread generators instead of one large-scale power plants, allows to create a flexible network of energy sources where the use of the primary fuel is optimized according to the concept of Distributed Generation (DG). Micro Gas Turbines (MGT) offer many advantages compared to other CHP units. Natural Gas (NG) is normally used to power gas turbines because of its large availability, low cost and consistent composition. Using biofuels derived from agricultural, industrial municipal wastes and renewable sources represent a way to reduce the greenhouse gas emissions of the energy generation sector. This kind of fuels usually derive from a gasification or pyrolysis process or from anaerobic digestion; therefore, they present low Lower Heating Value (LHV) that usually requires a redesign of some of the components of the MGT and an evaluation of the variation of the operation points of the turbo compressor group. The aim of this Ph.D. thesis work is to demonstrate the viability of the operation of a MGT with low LHV fuels trying to overcome the present technical limitations and to ensure the highest possible fuel flexibility.