Characterization of agricultural residues: Physical and chemical analysis for energy transformations

The use of agricultural residues for energy production determines economic and environmental benefits for the agricultural sector. Among the lignocellulosic biomasses, the residues of agricultural crops such as prunings of olive trees, vines and hazels could be play a key role for the italian agricultural sector. The aim of this work is to evaluate the physical and chemical characteristics of these residues in order to obtain information on the potential use in energy transformation processes such as combustion, pyrolysis and gasification. The analysis of biomass characterization includes the evaluation of moisture content, ash content, volatile matter, fixed carbon, total solid, lower and higher calorific value and elemental composition in terms of carbon, hydrogen, nitrogen and sulphur content. The results show that the moisture content is higher in vine and hazel prunings (18.50 % w/w and 11.80 % w/w) than in olive tree prunings (9.80 % w/w). The ash content is below 3 % w/w for all residues and carbon content ranges from 47 % w/w to 50 % w/w. These results show that the agricultural lignocellulosic residues could be used as resource for combustion processes for production of heat and power or in pyro-gasification processes for production of syngas and biochar that represents a good soil improver.