Analysis of the Work Productivity and Costs of a Stationary Chipper Applied to the Harvesting of Olive Tree Pruning for Bio-Energy Production

Alessandro Suardi,Luigi Pari,Simone Bergonzoli,Vincenzo Alfano,Nadia Palmieri,Francesco Latterini

doi:10.3390/en13061359

Alessandro Suardi, Luigi Pari + Show 4 more

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https://doi.org/10.3390/en13061359

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Abstract

Pruning residues could represent an important biomass resources for energy production. Only in Italy it has been estimated that an annual quantity of biomass of over 2600 kt of dry matter could be obtained from olive residues. Several machines developed for pruning harvesting are available in the market, most of which are tractor-driven, while limited knowledge is available on performance, quality of work and costs of harvesting logistics based on stationary chippers. The aim of the present paper is to analyze machine performance of a forestry stationary chipper applied to pruning harvesting for what concerns work productivity, quality of the comminuted product and harvesting operating costs. This system is actually applied by Fiusis Company, an Italian enterprise which manages a biomass power plant exclusively powered by olive trees’ pruning residues, and it has never been analyzed in literature. The results obtained showed consistent work productivity, which resulted the highest ever found in olive pruning harvesting systems and equal to 5.23 ± 0.81 tdm·h−1. This high work productivity allowed also to obtain a little economic gain from a matter, which is actually considered a problem for olive groves’ owners and not a potential source of income. In particular, the use of a stationary chipper seemed very efficient in olive groves with a consistent amount of wooden residues to be processed and with big branches not harvestable by the most common towed pruning harvester. In addition, the stationary chipper has the advantage of avoiding the preliminary raking operation, which results in reduced costs for the farmer.

Highlights

Fruit orchards cover over 10 million hectares across the EU and are mostly located in Mediterranean areas [1]
This operation generates a substantial amount of residues, estimated in the range of 1-5 tons per hectare [2], and an estimated annual quantity of pruning biomass of over 2600 kt of dry matter from the only olive groves in Italy [3] that could represent an important source of biomass for energy production [4]
The harvesting system based on the stationary chipper showed a very high harvesting efficiency, because the tractor with fork accumulated the pruning biomass without pauses near the uploading equipment that fed the chipper continuously

Summary

Introduction

Fruit orchards cover over 10 million hectares across the EU and are mostly located in Mediterranean areas [1]. All orchards require regular pruning, which is performed at 1–3-year intervals This operation generates a substantial amount of residues, estimated in the range of 1-5 tons per hectare [2], and an estimated annual quantity of pruning biomass of over 2600 kt of dry matter from the only olive groves in Italy [3] that could represent an important source of biomass for energy production [4]. These residues are usually field-burnt or mulched [5,6,7]. Field burning causes uncontrolled greenhouse gases (GHG) emissions, and mulching, Energies 2020, 13, 1359; doi:10.3390/en13061359 www.mdpi.com/journal/energies

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