Innovative plants for distributed poly-generation by residual biomass

The valorization of residual biomass plays a decisive role in the actual implementation of the concept of “circular economy”, according to which each waste material must be reused at its highest level in order to reduce the impact of human activities on the biosphere. The Italian project “INNOVARE-Innovative plants for distributed poly-generation by residual biomass”, funded by the local Ministry of Economic Development (MISE), involves the synergic activities of research institutes and industrial companies to pursue the aim of improving micro-cogeneration technologies fueled by biomass, in order to provide effective solutions of short-range biomass-to-energy chains, characterized by high overall efficiency and flexibility. A place for operational demonstration is chosen in the Municipality of Laurino, in the Cilento National Park, located in the Campania region, in the South of Italy. Main problems today still hindering a sustainable use of energy systems powered by biomass in various contexts are related the resource availability over a continuous time scale and to the necessity of extending their operating range in the absence of faults, to assure reliability. Within the project INNOVARE, a micro combined heat and power (mCHP) unit produced and marketed by the Italian Company CMD, the CMD ECO20 system, made of a gasifier, a syngas cleaning system and a spark ignition (SI) internal combustion engine (ICE) working as a co-generator, is chosen as the case study to assess the whole study. The availability of local biomasses is established by studying the agro-industrial production and by identifying forest areas to be properly managed through an original approach using the satellite location system based on the microwave technology. Woodchip from wood maintenance and olive-pomace from oil mills are also identified as possible feedstock for the system. A detailed experimental characterization of the selected cogeneration system is performed in order to identify its main inefficiencies. Numerical models of each component, validated against experimental data, are developed and used to optimize the performance of the whole conversion process. An improvement of the 5.8% on the electrical power is reached by identifying the optimal spark timing strategy. The waste heat recovery loop is modified in order to have at disposal the excess heat when the request for thermal load gets lower than the production capacity of the plant, with an increase in reliability even in the absence of thermal users. The positive development of the planned activities will have important effects at European level, by contributing to the diffusion of renewables, especially in areas where their penetration has been limited by the use of systems powered by non-programmable sources, in line with the principal current priorities of the European 2030 Climate & Energy Framework