Integrated harvesting and biomass haulage of olive tree prunings. Evaluation of a two year harvesting campaign in central Greece and fuel characterization of the prunings collected

Abstract

The aim of the present paper is to evaluate the most intensive demonstration of harvesting of olive tree prunings (OTP) ever occurred in Greece. In Agios Konstantinos, an integrated shredder was used to harvest the local olive groves. The harvesting campaign was performed for two consecutive years. In total, for both years, the harvesting campaign lasted for 20 days where around 81 ha of olive groves were harvested, that amounted to 252 dry Mg of harvested prunings. The aim of the paper is to evaluate an agricultural residue mobilization value chain in terms of performance, economics and fuel analyses of the harvested OTP. Via detailed monitoring, the present paper compares the harvesting demonstration results for both years. In brief, the average material capacity increased from 2.2 dry Mg/h (first year) to 2.4 dry Mg/h (second year), whereas the corresponding harvesting and haulage costs of these harvesting campaigns were calculated at 62.3 €/Mg (dry basis) and 63.7 €/Mg (dry basis), with an estimated commercial operation cost at 46.0 €/Mg (dry basis). Finally, from 49 samples of OTP collected, the average moisture content was at 27.5% (as received), ash content at 4.5% (dry basis) and the average LHV at 12.2 MJ/kg (as received).