The attention regarding bioenergy sources, such as biomass, as an alternative to fossil fuels has increased tremendously over the past few years consequently to the problems related to global warming. For the using of biomass as fuel is very important the basic knowledge of its physical-chemical properties for the using of the sustainable resource. The identification of biomasses in terms of both quantification and characterization of the chemical composition of biomass is a fundamental step for the use of this fuel for energy purposes. There are many differences between the various types of biomass; firstly, the moisture, the chemical composition and in particular that of the ashes, and the content of inorganic substances. The elements mainly present in biomass, in decreasing order of abundance are: carbon, oxygen, hydrogen, nitrogen, calcium, potassium, silicon, magnesium, aluminum, sulfur, iron, potassium, chloride, sodium and manganese. In addition, compared to coal, the chemical composition of biomass is significantly different, in particular the biomasses are highly enriched in hydrogen, manganese, potassium, phosphorus, chlorine, calcium, sodium and magnesium, as well as in terms of moisture and volatile substances compared to coal, while result with a lower ash content, iron, carbon, nitrogen, sulfur, and silicon. The purpose of this work is the quantification and characterization of different types of biomass found in the regions of the southern Italy with similar soil and same climatic conditions, at the end of their use in mixtures in an optical of build several ultrashort bioenergetical chains. Experimental results have shown that the heavy metal content is significantly lower in the fly ash than the bottom ash, and therefore, their mixture may be used as a soil improver to maintain the cycle of nutrients in soils. (C) 2014 Elsevier Ltd. All rights reserved.