• Energy Research

In the transition from linear production systems, unsustainable from the point of view of resources, to a model that finds strength in environmental, social and economic sustainability, the circular economy paradigm is the foundation that facilitates the planetary agro-ecological transition. The European Union has taken a number of steps (including the Circular Economy Package of Directives) shaping circularity as a wide-ranging driver measure involving many sectors. The paper intends to provide a regulatory framework on the current general situation regarding circularity in European Union, in order to extrapolate and give evidence to the aspects that intersect the agri-food sector. This is not only because they are poorly addressed in the literature, but also because there is a lack of regulatory instruments on the circular economy specifically addressing this area of interest. For this purpose, the analysis focuses on waste and residue/scrap management issues, recognized by law as by-products and end-of-waste status, as they are covered by circular economy legislation and as they can be applied to the agri-food sector. The latter allow the implementation of circularity strategies in the agri-food sector and, given the numerousness of production chains and the peculiarities of each of them, various regeneration and/or reuse processes of specific resources may be depicted. The intent is to provide useful knowledge on how to implement sustainable waste management, also proposing a concrete case on a by-product of olive oil processing, through which it is possible to highlight how the correct application of regulations favors the adoption of circular economic and management models in the firms involved, as well as informing the relevant economic operators on the possible profiles of legal liability that may arise from insufficient knowledge. Furthermore, this paper delves into the European Green Deal’s Strategy as it enriches the circular economy paradigm with new facets. NextGenerationEU and the National Recovery and Resilience Plan financially support this strategy in the aftermath of the socioeconomic crisis from COVID-19 in the EU Member States. This is in order to achieve the objective of achieving the agro-ecological transition.

Abstract Straw can be valorised through a set of unconventional applications other than the traditional ones being mainly related to livestock breeding. It can be utilised in bioenergy field as renewable feedstock for anaerobic digestion and other biological processes, or as fuel for direct combustion. However, it can also find suitable application in buildings as a multiple-function material (i.e. enveloping and insulation) or for production of other building materials. This paper investigates an Expanded Clay Granulate (ECG) production system in Sicily where straw is used as fuel in the cooking/expansion process, and so contributes both fields: buildings and bioenergy. In this study, the authors carried out a comparative Life Cycle Assessment (LCA) according to the subject International Standards, to environmentally validate shifting from hard coal to Durum Wheat (DW) straw as fuel for cooking and expansion of input fresh clay in a rotary kiln line. Study development provided the definition of the system functional unit and boundaries: the former was represented by the production of thermal energy as required for the making of 1 m3 ECG, depending upon whether the kilning phase is fuelled with hard coal or DW straw. Whilst, the latter were designed to include all processes for which differences were recorded due to the change in the fuel utilised. The study documented that, despite the environmental impacts associated with DW straw production, the hard coal fuelled system is far more impacting than that providing straw utilisation, mainly because of the related huge emissions of carbon dioxide.

The reduction of carbon emissions is a worldwide global challenge and represents the objective of many scientists that are trying to modify the role of carbon, turning a problem into an opportunity. The potential of CO2 capture and storage by vegetal species is significant because of their capacity to absorb exceeding carbon emission. The purpose of the present paper is to draw a picture of the role of vegetal ecosystems on carbon fixation by identifying the most significant scientific contributions related to the absorption by vegetal species. In particular the aim of this paper is to examine different forms of CO2 sequestration made by plants and crops involved in reducing greenhouse gas (GHG) emission. Results highlight the important role played by agricultural soils, forests, perennial plants, and algae, looking at the overall reduction of carbon emissions. In addition, results show that some bioenergy crops allow substantial storage of carbon dioxide, providing a significant contribution to climate change mitigation.

Farming systems need to be planned to provide suitable levels of economic profitability and, at the same time, ensure an effective energy use, in order to perform environmentally friendly production strategies. The herein present work aims to assess the efficiency of energy use and economic impacts of the main farming methods (conventional, organic and integrated) of Clementine’s crops in Calabria (South Italy), through a combined use of Life Cycle Energy Assessment (LCEA) approach and economic analysis. For this purpose, data were collected from clementine producers by using face-to-face interviews. The results revealed that average energy consumption in the organic farming systems was 72,739 MJ, lower than conventional and integrated systems equal to 95,848 MJ and 94,060 MJ, respectively. This is mainly due to the ban of chemicals. Economic analysis showed that organic farms were more profitable compared with the other farming methods, because of the greater selling price and the EU economic support, reaching an average net profit of 4255 € ha−1 against 3134 € ha−1 of integrated farms and 2788 € ha−1 of conventional ones. The economic efficiency of energy from clementine production was 0.058 € MJ−1 in the organic farming, higher compared to the other two farming systems equal to 0.033 € MJ−1 on average.

Agro-industrial transformation chains generate huge amounts of by-products which can be used as biomass for anaerobic digestion (AD) process, by avoiding their disposal in landfill and therefore environmental issues. This study has investigated a biomass mix to increase biogas production optimizing AD process parameters with the aim of enhancing AD performance in terms of produced biogas quality. In detail, both Biochemical Methane Potential (BMP) and AD approaches were adopted for investigating the effect of mixing seven Mediterranean feedstocks (i.e., olive pomace, citrus pulp, poultry and cattle manure, whey, tomato peels, and cereal straw) on methane production for bioenergy generation. The BMP test demonstrated that the tested mix had potential to be used for biogas production with 60.9% of methane content in the produced biogas. In detail, the specific production was equal to 343.1 Nm3CH4/tVS, confirmed by the results obtained during the AD test, about 333 Nm3CH4/tVS. As result, the tested mix demonstrated good net energy outputs and provide a flexible and useful solution to generate bioenergy from by-products. These findings confirm the possibility of using these by-products as energy sources and initiating virtuous bioeconomy processes for the sustainable utilization of renewable natural resources, transforming waste-to-resources.

This research was carried out to evaluate a local biogas plant's solid fraction digestate spreading in a citrus orchard and vineyard. Three spreaders were tested: a broadcast manure spreader in the citrus orchard, and two cylindrical-shaped spreaders in the vineyard; the first one working in broadcast configuration, the second one in localised configuration. Experimental tests assessed effective work time, mean work speed, digestate flow rate and longitudinal and transverse spreading uniformity. In the citrus orchard, the digestate was mainly spread in the centre of the inter-row (around 66%), with low variability between inter-rows (coefficient of variation (CV) equal to 2.7%) and much higher variability within inter-rows (CV = 31.4%). The effective work time was about 28% of total field time and real work capacity was about 0.96 ha h-1. In the vineyard, broadcast spreading released more on the right compared to the left (ratio 1.74) due to distributor disc rotation, whereas localised spreading was more uniform. Overall, variability between inter-rows had CV = 15.1% and within inter-rows CV = 33.3%. Real work capacity was about 0.16 ha h-1 for broadcast spreading and 0.26 ha h-1 for localised spreading. A preliminary economic evaluation, based on sub-contractor tariffs, produced the mean tariff for transaction and spreading costs of digestate in farms near the biogas plant.

We conducted a non-hypothetical choice experiment through a second price sealed bid experimental auction (Vickrey auction) to estimate the willingness to pay (WTP) to buy a new functional snack made with white lupine and citrus fiber, which are ingredients with high fiber content. A sample of 289 consumers were surveyed in Bologna and Catania in July 2015. The results confirm that consumers are willing to pay to buy functional foods, especially those who are looking for innovative products that are not influenced by the opinions of others in the buying decision. In addition, WTP did not depend exclusively on the functional properties but also on other characteristics such as appearance and taste of the snack. Italian Review of Agricultural Economics, Vol 70 No 3 (2015)