Small-scale biomass gasification CHP systems: Comparative performance assessment and monitoring experiences in South Tyrol (Italy)

During the last years, there was an increasing interest in small-scale biomass gasification system for combined heat and power (CHP) generation in South-Tyrol (Italy). The large number of plants based on various technologies and installed in a rather small area allowed carrying out a comparative study on a representative set of small-scale gasification-based commercial CHP unit. Each of the selected plants was monitored on-site for a time span of at least 5-6 h, measuring and quantifying mass and energy fluxes. The feedstock and the solid residue (char) have been characterized in terms of elemental composition, ash content and calorific value. The producer gas composition was measured, and tars collected in accordance with international sampling standard methodologies and analyzed. Moreover, environmental aspects have been taken into account, such as phytotoxicity levels in the char - the measurement of which has been performed by means of germination tests. This investigation resulted in a unique overview of the actual state-of-the-art of small-scale biomass gasification technology in Italy in terms of energy efficiency of the plants, effectiveness of the adopted solutions and characteristics of the products and by-products. (C) 2016 Elsevier Ltd. All rights reserved.