Use of agricultural by-products in the development of an agro-energy chain: A case study from the Umbria region

Life cycle cost analysis of agri-food products: A systematic review

Because of the increasing challenges the global food system is facing on a social, economic and environmental level, and the need to meet the United Nations Sustainable Development Goals (SDGs) by 2030, agri-food systems are increasingly required to become more sustainable. Life cycle tools, such as a life cycle assessment (LCA) and life cycle cost analysis (LCC) to evaluate the environmental and economic performance respectively, play an important role in sustainability research. Contrary to LCA, the LCC methodology is not standardized for agri-food products. This study aims to obtain insights into the use of LCC in the agri-food sector using a systematic review approach. Data related to the methodology and findings of life cycle cost analyses of agri-food products were extracted from 92 articles, covering a wide range of products (crops: 59, food/drinks: 22, other: 11) and purposes. Currently, there is no consensus about LCC type definitions and the definition of different types of system boundaries amongst researchers. Furthermore, these and other methodological choices are often not reported in the analyzed studies. The data collection itself can also differ across studies, especially with regards to the inclusion of different cost categories. It is important to include each cost category since all categories have been identified as a costs hotspot in our list of studies (inputs: 84 %, labor: 62 %, machinery: 27 %, other: 39 %). Standardizing the LCC methodology is recommended to ensure comparability and enhance the scientific impact of studies. Integrating LCC results with findings from other life cycle tools, as done in 29 studies, can further support decision-making. The most common methods for integrating results are eco-efficiency analysis and multi-criteria decision analysis methods. In conclusion, it is clear that LCC is a very valuable tool, as a method on its own or complemented by other life cycle tools.

New methodology for assessing the environmental efficiency of transport: Application to the valorization of biomass from phytoremediation

It is known that any environmental remediation process must be approached as a system and that the transport of materials is key to determining its sustainability. The aim of this work is to establish how far it was possible to transport plant material from a phytoextraction process in such a way that the environmental gain of the remediation process is not compromised. In the absence of a general methodology to answer our question, a new methodology based on spatial analysis and the life cycle perspective is proposed to calculate, under different hypotheses and depending on the type of remediation, the maximum distance that a lorry can travel, taking as a limit the distance in which the environmental benefit would be equal to 0. The results obtained show that there are significant differences depending on the type of optimisation proposed for the transport route as well as the type of valorization of the plant material to be carried out. Thus, in the case of bioethanol, biomass could be transported up to 25 km. For biodiesel, it can be shipped over distances between 255 and 415 km and finally, if it is valorized by anaerobic co-digestion, biodigesters up to 267 km away could be sought for the most favourable case.

Life cycle assessment applied to waste management in Italy: A mini-review of characteristics and methodological perspectives for local assessment

Life cycle assessment (LCA) and related tools are commonly used to evaluate the potential environmental impacts of waste treatment scenarios. This manuscript presents a mini-review of studies published over the last 10 years in Italy and aims to investigate how life cycle thinking tools are applied to assess the environmental sustainability of local-level waste policies. Results reveal that different waste flows, technologies and policies have been investigated independently and in varying detail. Review suggests that boundary selection significantly affects LCA results; integration of different waste systems is therefore crucial to avoid spatial or temporal shifts of environmental impacts. Moreover, the description of methodological characteristics, limitations and transversal aspects of Italian waste management studies allows various stakeholders to assess the reliability of past and future research for waste policy planning and rebound effects prevention. This review also highlights the need to define minimum requirements of transparency and ease of reporting of the studies to private and public stakeholders. Finally, the paper investigates whether using both the organisational LCA and the life cycle sustainability approach for the overall waste management process may be useful to develop a standard method to address multi-functionalities and multiple sites.

Comparative secretome of white-rot fungi reveals co-regulated carbohydrate-active enzymes associated with selective ligninolysis of ramie stalks

In the present research, Phanerochaete chrysosporium and Irpex Lacteus simultaneously degraded lignin and cellulose in ramie stalks, whereas Pleurotus ostreatus and Pleurotus eryngii could depolymerize lignin but little cellulose. Comparative proteomic analysis of these four white-rot fungi was used to investigate the molecular mechanism of this selective ligninolysis. 292 proteins, including CAZymes, sugar transporters, cytochrome P450, proteases, phosphatases and proteins with other function, were successfully identified. A total of 58 CAZyme proteins were differentially expressed, and at the same time, oxidoreductases participated in lignin degradation were expressed at higher levels in P. eryngii and P. ostreatus. Enzyme activity results indicated that cellulase activities were higher in P. chrysosporium and I. lacteus, while the activities of lignin-degrading enzymes were higher in P. eryngii and P. ostreatus. In addition to the lignocellulosic degrading enzymes, several proteins including sugar transporters, cytochrome P450 monooxygenases, peptidases, proteinases, phosphatases and kinases were also found to be differentially expressed among these four species of white-rot fungi. In summary, the protein expression patterns of P. eryngii and P. ostreatus exhibit co-upregulated oxidoreductase potential and co-downregulated cellulolytic capability relative to those of P. chrysosporium and I. lacteus, providing a mechanism consistent with selective ligninolysis by P. eryngii and P. ostreatus.

The Opportunity of Valorizing Agricultural Waste, Through Its Conversion into Biostimulants, Biofertilizers, and Biopolymers

The problems arising from the limited availability of natural resources and the impact of certain anthropogenic activities on the environment must be addressed as soon as possible. To meet this challenge, it is necessary, among other things, to reconsider and redesign agricultural systems to find more sustainable and environmentally friendly solutions, paying specific attention to waste from agriculture. Indeed, the transition to a more sustainable and circular economy should also involve the effective valorization of agricultural waste, which should be seen as an excellent opportunity to obtain valuable materials. For the reasons mentioned above, this review reports and discusses updated studies dealing with the valorization of agricultural waste, through its conversion into materials to be applied to crops and soil. In particular, this review highlights the opportunity to obtain plant biostimulants, biofertilizers, and biopolymers from agricultural waste. This approach can decrease the impact of waste on the environment, allow the replacement and reduction in the use of synthetic compounds in agriculture, and facilitate the transition to a sustainable circular economy.

Life cycle energy and environmental impacts of a solid oxide fuel cell micro-CHP system for residential application

Fuel cells are considered one of the key technologies to reach the ambitious European goal of a low carbon economy, by reducing CO₂ emissions and limiting the production of other pollutants. The manuscript presents an assessment of the life cycle energy and environmental performances of a solid oxide fuel cell system for household applications using primary data from the manufacturing phase and experimental data for the start-up and operation phases. The Life Cycle Assessment methodology is applied, based on a functional unit of 1 MJ of exergy and includes the life cycle steps from the raw materials extraction to the maintenance. The results show a particular relevance of the operation stage on the impacts (about 98% of cumulative energy demand and more than 63% of about half of the examined environmental impacts), mainly due to the fuel supply and, focusing on climate change, to the CO₂ emissions during the conversion of chemical energy into electricity. Manufacturing step is the main responsible of the remaining half of the impacts, with a contribution higher than 38%, mainly imputable to the stacks production. For almost half of the examined impact, a contribution of 20-30% is caused by the maintenance step, with a relevant contribution of the stacks and DC/DC booster substitutions. The analysis highlights that eco-design solutions of the assessed system can be traced in the improvement of the energy system efficiency and reduction of emissions during the operation, and in the increase of the durability of the system components, thus reducing the number of their substitutions. The results of a sensitivity analysis on the selection of the functional unit also clarified the importance of the recovery of the thermal energy generated by the fuel cells, in order to avoid concurrent energy generation from conventional sources.

The Future Agricultural Biogas Plant in Germany: A Vision

After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.