“Residual biomass for energy”

Every year within the European Union the quantity of biomass collected corresponds to 2.2 billion GJ, of which approximately 1.7 billion GJ is used to generate thermal energy, while 0.5 billion GJ to produce electricity. Biomass used for energy, often constituting a main production residue in agriculture, forestry, agro-industry, zootechnics, etc., could contribute to the solution to some of current society’s problems, such as the growing need of energy sources as an alternative to fossil fuels, climate change due mainly to the greenhouse effect and, moreover, the reduction of environmental impact deriving from disposal of such substances. It is by now common knowledge that agriculture no longer represents the solution to the future energy problems of mankind; it can, however, make a significant contribution during the transitional phase from current use of fossil sources to that of renewable energy, which will hopefully be free of energy and environmental difficulties. Indeed, agriculture can only play a complementary role, since its main function is to supply food sources which are indispensable to an ever growing population, more so in emerging countries. This is the topic of an increasing worldwide scientific debate involving the main international organisations who express grave concern and dissent over the designation of agricultural products for energy purposes. Such a choice has already determined the current price increase in some food raw materials. In this context also energy crops present a series of problems, such as the availability of land and water which would inevitably be subtracted from food crops for human consumption, the negative impact on crop biodiversity, etc. In Italy more than 17 million tons of biomass is available per year (90% of which from agricultural and forest residues), amounting to a gross production of electric and/or heat energy currently estimated at approximately 6,745 GWh (total energy production is about 301.226 GWh per year). The present study intends to analyse, in particular, the situation in Apulia region, a predominantly agricultural area of southern Italy, in order to estimate the amount of useable residual biomass, highlighting current limitations and prospects of use and recovery, while taking into account other probable uses, land availability and possible interaction with food production. Study of literature has indicated the scarce availability of data regarding the amount of single biomass residues from agricultural, forest and food processing activity. This is essentially due to the lack of detailed analysis on a national level and to the difficulty in carrying out a comparison of the data, often due to lack of homogeneity. Moreover, the aforementioned residues, though of a significant quantity, are not easy to measure due to their considerable pulverisation in the territory and the difficulty in quantifying that part used within the same farms. Key words: recovery of biomass residues, biomass resources, regional bioenergy potential.