A distributed micro-cogeneration system has been developed for continuous and programmable autonomous production of thermal (between 25 and 70 kWth) and electrical (between 5 and 10 kWel) energy starting from heterogeneous biomasses. A global thermal efficiency greater than 80%, the availability of electricity and thermal energy h24h 365g / year in every not-desert region of the world, even the most remote, ultra low levels of emissions of solid and gaseous pollutants and the possibility of feeding with different types of biomass , mainly of vegetable origin, are the benchmarks of expected performance.
It is based on an innovative coupling scheme between a fluidized bed combustor and a Stirling engine which sees the engine exchanger directly immersed in the bed. This determines an extremely efficient heat exchange and eliminates the problems of exchanger fouling that afflict all systems based on traditional boilers and exchangers immersed in the exhaust gas stream.
The micro-generators from traditional renewable sources (for example photovoltaic, wind, solar thermal and thermodynamic), do not provide energy in a continuous and programmable way unless coupling expensive and problematic storage systems (such as batteries and thermal storage) and are rarely co-generators. The proposed system possesses all these features. Fluidized bed combustors allow the use of self-produced residual biomass or available at zero km with simple pre-treatments and therefore, like other alternative sources, of very low or even negative cost (savings on disposal costs). Biomass can be stored for very long times in easy to build deposits. These features, together with the high strength, low noise and reduced maintenance of the Stirling engines, result in a competitive overall cost of operation. The markets having very high potential are in the residential, agro-industrial and service sectors and in the energy self-sufficiency of underdeveloped regions.