Biomass Thermal Treatment: Energy Recovery, Environmental Compatibility and Determination of External Costs

Abstract

Climate change is the primary worldwide issue of the twenty-first century, as it threatens not only natural ecosystems but many national economies as well. Since the major contributor to climate change is the emission of greenhouse gases, switching to renewable and clean sources of energy production would result in the most immediate benefit. And one of the main energy sources in this category is biomass. In this work some preliminary evaluations are reported concerning the environmental effects, as well as the related external costs, from both local and global points of view, of a proposed biomass plant to be constructed in Piedmont (northern Italy). The obtained results indicate that, from the local point of view, the environmental effectiveness of the plant is related to the percentage of the thermal energy that can be transferred from the district heating network to the local domestic boilers (with subsequent replacement of the related emissions). From a global point of view, and in particular concerning greenhouse gases (GHG), the carbon dioxide produced from biomass combustion would be balanced by the quantity that is absorbed by the plants during their lifetimes. Hence by operating a biomass plant capable of producing 20 thermal MW, we can remove carbon dioxide emissions equal to about 38.368 ton/year, and avoid external costs of 728.992 €/year, if at least 30% of the produced heat can be transferred to the district heating network.