Search Results (115)

In recent decades, the rapid expansion of the food processing industry has led to significant losses and waste, with the fruit and vegetable sector among the most affected. According to the Food and Agriculture Organization of the United Nations (FAO), losses in this category can reach up to 60%. Vegetable waste includes edible parts discarded during processing, packaging, distribution, and consumption, often comprising by-products rich in bioactive compounds such as polyphenols, carotenoids, dietary fibers, vitamins, and enzymes. The underutilization of these resources constitutes both an economic drawback and an environmental and ethical concern. Current recovery practices, including their use in animal feed or bioenergy production, contribute to a circular economy but are often limited by high operational costs. In this context, fermentation has emerged as a promising, sustainable approach for converting vegetable by-products into value-added food ingredients. This process improves digestibility, reduces undesirable compounds, and introduces probiotics beneficial to human health. The present review examines how fermentation can improve the nutritional, sensory, and functional properties of plant-based foods. By presenting several case studies, it illustrates how fermentation can effectively valorize vegetable processing by-products, supporting the development of novel, health-promoting food products with improved technological qualities. Full article

Small-scale fisheries and aquaculture play a crucial role in securing food, income, and nutrition for millions, especially in the Global South. Rural small-scale aquaculture (SSA) is characterized by limited investment and technical training among farmers, diversification and dispersion of farms over large areas, reduced access to competitive markets for inputs and products, and family labor. Small-scale integrated circular aquaponic (ICAq) systems, in which systems’ component outputs are transformed into component inputs, have significant potential to increase circularity and promote economic development, especially in a rural context. We offer an integrated and comprehensive approach centered on aquaponics or aquaponic farming for small-scale aquaculture units. It aims to identify and describe a series of circular processes and causal links that can be implemented based on deep study in SSA and ICAq. Circular processes to treat by-products in ICAq include components like composting, vermicomposting, aerobic and anaerobic digestion, silage, and insect production. These processes can produce ICAq inputs such as seedling substrates, plant fertilizers, bioenergy, or feed ingredients. In addition, the plant component can supply therapeutic compounds. Further research on characterization of aquaponic components outputs and its quantifications, the impact of using circular inputs generated within the ICAq, and the technical feasibility and economic viability of circular processes in the context of SSA is needed. Full article

This study presents a social life cycle assessment (S-LCA) of the F-CUBED Production System (FPS), an innovative process that converts wet biogenic residues—specifically paper biosludge, virgin olive pomace, and fruit and vegetable residues—into intermediate bioenergy carriers via hydrothermal treatment (TORWASH^®), pelletization, and anaerobic digestion. The hydrothermal carbonization of these low-grade, moisture-rich biogenic residues enhances the flexibility and reliability of renewable energy systems while also offering the potential to reduce environmental burdens compared to conventional disposal methods. Through this S-LCA, the study aims to evaluate the cradle-to-gate socioeconomic impacts of the FPS in three European contexts—Sweden, Italy, and Spain—using the 2020 UNEP Guidelines and the Social Hotspots Database (SHDB) and applying quantitative modeling via SimaPro. The functional unit is defined as 1 kWh of electricity produced. The assessment combines SHDB-based modeling with primary data from stakeholder surveys conducted in the three countries. Impact categories are harmonized between SHDB and UNEP typologies, and the results are reported in medium-risk-hour equivalents (mrheq). The results show a heterogeneous social impact profile across case studies. In Sweden, the treatment of paper biosludge delivers substantial benefits with minimal risk. In Spain (orange peel), the introduction of the FPS demonstrated a strong social benefit, particularly in health and safety and labor rights, indicating high institutional performance and good integration with local industry. Conversely, in Italy (olive pomace), the FPS revealed significant social risks, especially in the biopellet production and electricity generation sectors, reflecting regional vulnerabilities in labor conditions and governance. This suggests that targeted mitigation strategies are recommended in contexts like Southern Italy. These findings highlight that the social sustainability of emerging bioenergy technologies is context-dependent and sensitive to sectoral and regional socioeconomic conditions. This S-LCA complements prior environmental assessments and emphasizes the importance of integrating social performance considerations in the deployment and scaling of innovative bioenergy systems. Full article

This study systematically compares the environmental and economic performance of three wastewater treatment systems: constructed wetlands (CWs), microbial fuel cells (MFCs), and their integration (CW–MFC). Lab-scale units of each system were constructed using a multi-media matrix (gravel, zeolite, and granular activated carbon), composite native wetland species (Juncus effusus, Iris sp., and Typha angustifolia), carbon-based electrodes (graphite), and standard inoculum for CW and CW–MFC. The MFC system employed carbon-based electrodes and proton-exchange membrane. The experimental design included a parallel operation of all systems treating domestic wastewater under identical hydraulic and organic loading rates. Environmental impacts were quantified across construction and operational phases using life cycle assessment (LCA) with GaBi software 9.2, employing TRACI 2021 and ReCiPe 2016 methods, while techno-economic analysis (TEA) evaluated capital and operational costs. The key results indicate that CW demonstrates the lowest global warming potential (142.26 kg CO₂-eq) due to its reliance on natural biological processes. The integrated CW–MFC system achieved enhanced pollutant removal (82.8%, 87.13%, 78.13%, and 90.3% for COD, NO₃, TN, and TP) and bioenergy generation of 2.68 kWh, balancing environmental benefits with superior treatment efficiency. In contrast, the stand-alone MFC shows higher environmental burdens, primarily due to energy-intensive material requirements and fabrication processes. TEA results highlight CW as the most cost-effective solution (USD 627/m³), with CW–MFC emerging as a competitive alternative when considering environmental benefits and operational efficiencies (USD 718/m³). This study highlights the potential of hybrid systems, such as CW–MFC, to advance sustainable wastewater treatment technologies by minimizing environmental impacts and enhancing resource recovery, supporting their broader adoption in future water management strategies. Future research should focus on optimizing materials and energy use to improve scalability and feasibility. Full article

Anaerobic digestion (AD) offers a sustainable solution by treating biodegradable waste while recovering bioenergy, enhancing the share of renewable energy. Thus, this study aims to investigate the AD for managing and valorizing residues from the potato chip industry: potato peel (PP), potato offcuts (OC), waste cooking oil (WCO), wastewater (WW), and sewage sludge (SS). In particular, the biochemical methane potential (BMP) of each residue, anaerobic co-digestion (AcoD), and greenhouse gas (GHG) emissions of an AD plant are assessed. WW, OC, and SS present a BMP of around 232–280 NmL_CH4/kg of volatile solids (VS). PP and WCO reach a BMP slightly lower than the former substrates (174–202 NmL_CH4/g_VS). AcoD results in methane yields between 150 and 250 NmL_CH4/g_VS. An up-scaled anaerobic digester is designed to manage 1.60 Mg/d of PP. A residence time of 12 days and a digester with 165 m³ is estimated, yielding 14 Nm³_CH4/Mg_VS/d. A simulated AD plant integrated with a combined heat and power unit results in a carbon footprint of 542 kg of CO₂-eq/Mg_db PP, primarily from biogenic GHG emissions. These findings highlight the potential of AD to generate renewable energy from potato industry residues while reducing fossil fuel-related GHG emissions and promoting resource circularity. Full article

The anthropogenic deployment of plastic waste, especially petroleum-based plastics with toxic hydrocarbons, presents a significant environmental and health threat in sub-Saharan Africa (SSA). Herein, the high demand and rapid plastic production, coupled with improper disposal and inadequate waste management, have led to widespread contamination of air, water, and soil. Conventionally, plastic waste management, such as incineration and recycling, provides limited long-term solutions to this growing crisis. This necessitates urgent, sustainable, and eco-friendly remediation techniques to mitigate its far-reaching environmental implications. This comprehensive review focused on sustainable and eco-friendly techniques by exploring strengths, weaknesses, opportunities, and threats (SWOT) analysis of plastic waste management. Bioremediation techniques were found as potential solutions for addressing plastic waste in SSA. This paper examines advancements in physiochemical methods, the challenges in managing various plastic types, and the role of enzymatic and microbial consortia in enhancing biodegradation. It also explores the potential of genomic technologies and engineered microbial systems to convert plastic waste into valuable products, including bioenergy via bio-upcycling. These bioremediation strategies align with the United Nations Sustainable Development Goals (UN SDGs), offering a promising path to reduce the environmental and health impacts of plastic pollution in the region. This paper also considers future directions of integrating AI-powered recycling systems to facilitate the development of a circular economy in SSA. Additionally, this paper provides progress and future perspectives on bioremediation as a sustainable solution for plastic waste management in SSA. Full article

The global transition to a digital era is crucial for society, as most daily activities are driven by digital technologies aimed at enhancing productivity and efficiency in the production of food, fibers, and bioenergy. However, the segregation of digital techniques and equipment in both rural and urban areas poses significant obstacles to technological efforts aimed at combating hunger, ensuring sustainable agriculture, and fostering innovations aligned with the United Nations Sustainable Development Goals (SDGs 02 and 09). Rural regions, which are often less connected to technological advancements, require digital transformation to shift from subsistence farming to market-integrated production. Recent efforts to expand digitalization in these areas have shown promising results. Digital agriculture encompasses terms such as artificial intelligence (AI), the Internet of Things (IoT), big data, and precision agriculture integrating information and communication with geospatial and satellite technologies to manage and visualize natural resources and agricultural production. This digitalization involves both internal and external property management through data analysis related to location, climate, phytosanitary status, and consumption. By utilizing sensors integrated into unmanned aerial vehicles (UAVs) and connected to mobile devices and machinery, farmers can monitor animals, soil, water, and plants, facilitating informed decision-making. An important limitation in studies on nutritional diagnostics is the lack of accuracy validation based on plant responses, particularly in terms of yield. This issue is observed even in conventional leaf tissue analysis methods. The absence of such validation raises concerns about the reliability of digital tools under real field conditions. To ensure the effectiveness of spectral reflectance-based diagnostics, it is essential to conduct additional studies in commercial fields across different regions. These studies are crucial to confirm the accuracy of these methods and to strengthen the development of digital and precision agriculture. Full article

The economic impact of obtaining biomass could become significant to U.S. rural economies via the establishment of a bioeconomy. In 2023, the Bioenergy Technologies Office (BETO) and Oak Ridge National Laboratory provided a road map to obtain over a billion tons of biomass for conversion to bioenergy and other products. Using information from this roadmap, this study estimates the potential positive and negative economic impacts that occur because of land use change, along with increased technological advances. This is achieved by using the input–output model, IMPLAN, and impacting 179 Bureau of Economic Analysis regions in the conterminous United States. Biomass included in the analysis comprises dedicated energy crops, crop residues, and forest residues. The analysis found that managing pastures more intensively could result in releasing land to produce dedicated energy crops on 30.8 million hectares, resulting in the production of 361 million metric tons of biomass. This, coupled with crop residues from barley, corn, oats, sorghum, and wheat (162 million metric tons), plus forest residues (41 million metric tons), provide 564 million dry metric tons of biomass. Assuming the price for biomass in 2023 dollars was USD 77 per dry metric-ton, this additional production results in an economic benefit for the nation of USD 619 billion, an increase from the Business As Is scenario (Baseline) of almost USD 100 billion per year, assuming a mature biomass industry. An additional 700,000 jobs are required to grow, harvest/collect, and transport the biomass material from the land. Full article

Bioenergy is one of the renewable energy sources with high expectations in terms of its potential for greenhouse gas (GHG) emissions mitigation, and thus has been included in most global warming limiting strategies and pathways. However, within this context, a state-of-the-art and comprehensive understanding of the environmental performance of currently available bioenergy technologies is still missing. Hence, we conduct this critical review on life cycle assessment (LCA) studies regarding a wide portfolio of bioenergy technologies to deal with this lack of knowledge. Our critical review of exhaustively searched literature identified commonly existing limitations and difficulties in the selected LCAs in terms of essential aspects of LCA, i.e., system boundaries, functional unit (FU), multifunctionality, and impact categories. Key findings of our review are as follows: inconsistency of system boundary definitions, incomparability of LCA results due to various FU definitions, incomprehensiveness of impact categories, as well as a lack of uncertainty and sensitivity analysis. Finally, in view of the above findings, we present a generic guideline for future studies with the purpose of overcoming the identified shortcomings. Full article

Fossil fuels drive global warming, necessitating renewable alternatives such as biomethane (or renewable natural gas). Biomethane, primarily produced through anaerobic digestion (AD), offers a cleaner energy solution but is limited by the slow AD process. Biomass gasification followed by syngas methanation has emerged as a faster alternative. This review examines advancements in these processes over the last decade (2015–2024), focusing on techno-economic and life cycle assessment (LCA) studies. Techno-economic analyses reveal that biomethane production costs are influenced by several factors, including process complexity, feedstock type and the scale of production. Smaller gasification units tend to exhibit higher capital costs (CAPEX) per MW capacity, while feedstock choice and process efficiency play significant roles in determining overall production costs. LCA studies highlight higher impacts for gasification and methanation due to energy demands and associated emissions. However, integrating renewable hydrogen production through electrolysis, along with innovations such as sorption-enhanced gasification (SEG), can enhance overall system efficiency and reduce environmental impacts. This review critically evaluates the technical and economic challenges, along with the opportunities for optimizing biomethane production, and discusses the potential for these technologies to contribute to sustainable bioenergy solutions in the transition to a low-carbon economy. Full article

Portugal exhibits a large deficit in cereals with an import/export ratio of about 18%. Alentejo is a southern vast plain region, which is the largest cereal producer in the country, with about 80% of the total cereal area. The region also shows a huge local energy deficit with a ratio of about 17% between spent and produced energy. In this context, this work used GIS modeling based on available digital geographical information on soil and topographic conditions in Alentejo for estimating optimal production areas of four main classes of cereal and legume classes, which were wheat, barley, oat/lupin, and triticale/broad bean. The estimated areas were validated by 199 sample points in the field and allowed to quantify a potential of bioenergy production from straw biomasses based on yields of biomass net calorific values of 18 MJkg⁻¹ and yields of 6, 9, 6, and 9 tons/ha for the four classes in the order indicated. The estimated areas allocated to the cereal and legume classes covered approximately four municipalities in the region. The total modeled area in Alentejo for the four cultivation classes was 44,980 ha. The results showed that even if 50% of the estimated total straw biomass produced was used for animal feed, the estimated bioenergy production of the remaining half biomass would be of about 2940 TJy⁻¹, or about 12.5% of the actual regional energy production, which is an energy amount able to supply 35 organic Rankine cycle (ORC) 2.5 MW cogeneration units and 347 boilers with 125 kW thermal power, delivering renewable electricity to the grid, and heating facilities as diverse as buildings, nursing homes, or horticultural greenhouses. More than 160 kton of CO₂ fossil emissions would also be avoided, delivering a contribution to mitigating effects of climate change. By contributing to the reduction of the large cereal dependence and the carbon emissions of the country, the proposed strategy would contribute to increasing the decentralized bioenergy production for applications in buildings and local facilities, significantly boosting the socio-economic dynamics of rural areas involved. Full article

A plethora of sustainability-related challenges plague the modern world, among which is residue management. The significant implications of waste management on local populations and the global climate system have propelled research efforts toward residue management. Improved understanding and predictions in biomass residue management can help identify opportunities to advance residue management to address these complex challenges. In recent years, sustainability science has gained momentum and is viewed as the most effective approach to addressing wicked problems. For instance, the release of greenhouse gases into the atmosphere is a major contributor to climate change. This review examines how a greater knowledge of human–environment interaction and the value of ecological services could facilitate the recycling of agricultural and forestry wastes for their uses in bioenergy production and soil protection. In addition, it highlights the connection between biomass residual management and the United Nations Sustainable Development Goals, thereby strengthening the circular and ecological economy. Additionally, this review also discusses how interdisciplinary and systems thinking can contribute to the advancement of biomass residue management. This review aims to explore how the principles of sustainability science and systems thinking can help enhance the reutilization of agricultural and forest residues through biomass residue management. It also aims to assess their potential in reducing environmental and social impacts. Full article

Poor access to electricity in rural communities has been linked to a poor educational system, as electricity is essential for supporting laboratories, technical practice, and long study hours for students. Therefore, this work presents the techno-economic analysis of a hybrid solar PV–agro-wastes (syngas) energy system for electricity, heat, and cooling generation to improve energy access in rural schools. The system is located in Ghana at Tuna (lat. 9°29′18.28″ N and long. 2°25′51.02″ W) and serves a secondary school for enhanced quality education. The system relies on agro-waste (gasifier-generator) and sunlight (solar PV), with a battery energy storage system, to meet the school’s energy demand. The study employs HOMER Pro Version 3.16.2 software to comprehensively analyze technical, economic, and environmental aspects. The system can generate 221,621 kWh of electricity (at a unit cost of electricity of 0.295 EUR/kWh) and 110,896 kWh of thermal energy yearly. The cost of electricity from the proposed system is cheaper than the cost of electricity from an equivalent diesel generator at 0.380 EUR/kWh. The thermal energy can meet the heating demand of the school in addition to powering a vapor absorption chiller. The system is environmentally friendly, with the capacity to sink 0.526 kg of CO₂ yearly. Government policies that moderate interest rates for bioenergy/solar PV systems and social solution on feedstock pricing will favor the economic sustainability of the proposed system. The system will address the energy access challenge (SDG 7), enhance the quality of education (SDG 4), and contribute to climate mitigation through carbon sequestration (SDG 13). Full article

Policy priorities for wood-based bioenergy in North America have undergone fluctuations over time, influenced significantly by the dynamic interplay of sociopolitical factors. Recent years, however, have seen a renewed public interest in wood-based bioenergy in the United States, Canada, and Mexico. This resurgence is driven by fluctuating energy prices and growing concerns about climate change. This review provides an overview of current energy production and consumption scenarios, and highlights critical issues related to the sustainability of bioenergy feedstocks and their economic potential across the three North American countries. Different cross-cutting issues related to public health, climate change, and social acceptance of wood-based bioenergy are thoroughly examined. Within this context, several challenges have been identified, including uncertainties in climate projections, inadequate tree inventories beyond forestlands, deforestation concerns, technological shifts in wood processing, fluctuations in bioenergy demand, and the imperative need for access to reliable markets. Addressing these challenges requires increased research and investment in wood-based energy to enhance energy security, reduce greenhouse gas emissions, and improve economic and social viability in bioenergy production. This proactive approach is vital for fostering a sustainable and resilient wood-based bioenergy sector in North America. Full article

The United Nations Agenda 2030 for Sustainable Development has induced the empirics to find the factors that can contribute to sustainable development. However, limited empirical evidence has estimated the impact of forest trade, bioenergy, and economic policy uncertainty on sustainable development. This study fills the gap by analyzing the impact of forest trade, bioenergy, and economic policy uncertainty on sustainable development in China and the USA using the ARDL and QARDL approaches. The findings of the ARDL model suggest that forest trade helps boost both short- and long-run sustainable development in China and the USA, while bioenergy fosters sustainable development in the short and long run only in China and in the USA, bioenergy improves sustainable development only in the long run. In contrast, economic policy uncertainty hurts sustainable development in the short and long run in China, while in the USA, only the long-run negative association between the two variables is observed. Thus, policymakers in China and the USA need to focus on enhancing trade in forest products, fostering bioenergy generation, and reducing uncertainties in economic policy to promote sustainable development. Full article