Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kg_{dry solids}⁻¹ (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

A big amount of agricultural residues are generated from crop production and partially remain in the field after harvest. Removing the excess of residues after crop harvesting can increase farmer income, providing feedstock that could be used for industrial and energy purposes. The costs for collection and transport of straw and stalks are site- and region-specific and depend on the availability of agricultural residue and on how much of the residue is removed from any specific field or location. If the biomass is baled then it is required to upload the bales on a trailer, transport and unload all the baled biomass to the storage center. On the other hand, if a self-loading wagon is used the loose biomass collected, it must be unloaded every time the wagon is completely full. The distance and the harvesting system used influence the costs and should be analytically studied to avoid turning a possible profit into a disadvantageous business. The research represents a real case study to evaluate, which is the maximum distance to the biomass logistic center from which it is more economically convenient to gather the wheat and corn residues in bales instead of using a self-loading wagon. The results show a lower harvesting unitary cost for the self-loading forage wagon respect to the baling system. Although the study showed delivery distances over 11.4 km for wheat straw and 16.0 km for maize stalks, the use of the self-loading forage wagon is no longer convenient, and baling is the preferred harvesting system.

One of the main questions facing precision agriculture is the evaluation of different algorithms for the delineation of homogeneous management zones. In the present study, a new approach based on the use of time series of satellite imagery, collected during two consecutive growing seasons, was proposed. Texture analysis performed using the Gray-Level Co-Occurrence Matrix (GLCM) was used to integrate and correct the sum of the vegetation indices maps (NDVI and MCARI2) and define the homogenous productivity zones on ten durum wheat fields in southern Italy. The homogenous zones identified through the method that integrates the GLCM indices with the spectral indices studied showed a greater accuracy (0.18–0.22 Mg ha⁻¹ for ∑NDVIs + GLCM and 0.05–0.49 Mg ha⁻¹ for ∑MCARI2s + GLCM) with respect to the methods that considered only the sum of the indices. Best results were also obtained with respect to the homogeneous zones derived by using yield maps of the previous year or vegetation indices acquired in a single day. Therefore, the survey methods based on the data collected over the entire study period provided the best results in terms of estimated yield; the addition of clustering analysis performed with the GLCM method allowed to further improve the accuracy of the estimate and better define homogeneous productivity zones of durum wheat fields.

The valorization of agricultural residues plays a fundamental role in renewable energy production. Particularly, the management of olive orchards in Lazio region generates a considerable amount of biomass that is currently unexploited, but it could represent a valid source of solid biofuel for energy production in the Lazio region (Italy). Using a Geographic Information System (GIS) approach entirely based on open source software, five suitable areas (A, B, C, D and E) have been selected as eligible for hosting and feeding a 1 MWe power plant. Harvesting and transportation costs were also calculated. The harvesting operation costs were EUR 96.79 Mg_fm⁻¹ in A, while they ranged from EUR 49.83 Mg_fm⁻¹ (E) up to EUR 56.51 Mg_fm⁻¹ (D) for the other sub-areas. Sub-area A showed also higher transport costs, EUR 21.55 Mg_fm⁻¹ while the same value ranged from EUR 14.75 Mg_fm⁻¹ (E) to EUR 16.59 Mg_fm⁻¹ (B) in the other sub-areas. However harvesting costs resulted higher than those reported in the literature, mainly due to the low pruning yield per surface unit, an aspect which is directly related to the olive grove’s management in the region where annual pruning is the usual practice. Future developments of the present study should encompass the social and environmental aspects of residual biomass supply chains herein proposed.

The growing demand in food and non-food industries for camelina oil is driving the interest of farmers and contractors in investing in such feedstock. Nonetheless, the cost, performance and critical aspects related to the harvesting stage are still not properly investigated. In the present study, an ad-hoc test was performed in Spain in order to fulfill this gap. The results support the hypothesis to harvest camelina seeds with the same combine harvester used for cereal harvesting without further investment. Theoretical field capacity (TFC), effective field capacity (EFC), material capacity (MC), and field efficiency (FE) were 4.34 ha h⁻¹, 4.22 ha h⁻¹, 4.66 Mg h⁻¹ FM, and 97.24%, respectively. The harvesting cost was estimated in 48.51 € ha⁻¹. Approximately, the seed loss of 0.057 ± 0.028 Mg ha⁻¹ FM was due to the impact of the combine harvester header and dehiscence of pods, whilst 0.036 ± 0.006 Mg ha⁻¹ FM of seeds were lost due to inefficiency of the threshing system of the combine harvester. Adjustment of the working speed of the combine and the rotation speed of the reel may help to reduce such loss.

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 t_dm·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.