Sustainability Requirements Research Articles

Functional Alkali Metal-Based Ternary Chalcogenides: Design, Properties, and Opportunities.

The search for novel materials has recently brought research attention to alkali metal-based chalcogenides (ABZ) as a new class of semiconducting inorganic materials. Various theoretical and computational studies have highlighted many compositions of this class as ideal functional materials for application in energy conversion and storage devices. This Perspective discusses the expansive compositional landscape of ABZ compositions that inherently gives a wide spectrum of properties with great potential for application. In the present paper, we examine the technique of synthesizing this particular class of materials and explore their potential for compositional engineering in order to manipulate key functional properties. This study presents the notable findings that have been documented thus far in addition to outlining the potential avenues for implementation and the associated challenges they present. By fulfilling the sustainability requirements of being relativity earth-abundant, environmentally benign, and biocompatible, we anticipate a promising future for alkali metal chalcogenides. Through this Perspective, we aim to inspire continued research on this emerging class of materials, thereby enabling forthcoming breakthroughs in the realms of photovoltaics, thermoelectrics, and energy storage.

Evaluation and Prioritization of Power-Generating Systems Using a Life Cycle Assessment and a Multicriteria Decision-Making Approach

Millions of people in Asia and sub-Saharan Africa still lack access to power, which emphasizes the need for sustainable and clean energy solutions. This study attempts to address this issue by integrating a life cycle assessment (LCA) and a multicriteria decision-making (MCDM) analysis to determine the preferred energy technology for electrification. This research focuses on the environmental implications and long-term viability of various energy system options. The LCA evaluates midpoint characterization containing 18 environmental impact categories; the COPRAS and ARAS methods of MCDM analysis are then used to rank the energy alternatives based on their environmental performance. This study’s key finding is that the gas-powered power plant is the most preferred energy system alternative, while the geothermal power plant is the least preferred. This midpoint characterization study provides in-depth insights into how various stages contribute to major environmental impact categories like global warming, ozone depletion, and ecotoxicity. By considering environmental impacts and sustainability requirements, informed decisions may be made to encourage clean and cost-effective power generation, thereby contributing to climate change mitigation and supporting economic growth and human development. Future research may include analysis from cradle-to-grave compared to cradle-to-gate.

Nexus between technology enabled supply chain dynamic capabilities, integration, resilience, and sustainable performance: An empirical examination of healthcare organizations

Due to the twin impacts of the COVID-19 pandemic and sustainability requirements, many healthcare organizations face disruptions and uncertainties, which put patient safety at risk and decrease the overall quality of health services. Drawing on the dynamic capability view, this study aims at exploring the relationship among supply chain dynamic capabilities (SCDCs), supply chain integration (SCI), supply chain resilience (SCR), sustainable competitive advantage (SCA), and sustainable supply chain performance (SSCP). The study collected 325 usable responses from healthcare supply chain organizations in the developing country of Pakistan, including hospitals, pharmaceutical manufacturing firms, surgical and equipment manufacturing firms, etc. Structural equation modeling using Smart-PLS v.3.3.2 was adopted for the data analysis. The results indicate that SCDCs positively influence SCI, SCR, SCA, and SSCP. This study finds that SCA, SCI, and SCR mediate the relationship between SCDCs and SSCP. This study contributes by aligning the SC dynamic capabilities for supply chain visibilities (i.e., sensing, learning, and coordinating) in the healthcare context. It has examined the impacts of SCDC, SCI, and SCR collectively rather than addressing them piecemeal. Sensing, learning, and coordinating capabilities through frequent collaborative meetings offer healthcare firms SC integration, allowing them to respond to the changing environment quickly and resiliently, further improving their SCA and SSCP. Since disruptions are inevitable, healthcare organizations must turn uncertainties into opportunities and activate a dynamic and resilient strategy to absorb stress. SCA and SSCP improve when SCDCs/SCR and disruptions are properly balanced.

Generative AI for performance-based design of engineered cementitious composite

Engineered cementitious composite (ECC) has been intensively studied due to its excellent tensile performance. However, classical micro-mechanical design theory of ECC is qualitative and fails to give detailed ECC mixtures at specific tensile parameters. This study aims to develop a performance-based mixture design model to generate ECC mixtures using generative AI method. An experimental database consisting of 129 polyethylene fiber reinforced ECC (PE-ECC) records has been built. The database was used to train one invertible neural network model and two artificial neural network models. A series of PE-ECC mixtures were generated by the proposed model based on desired mechanical performance and sustainable requirements. Based on the experimental results, the developed model was proven to compose PE-ECC mixtures that satisfy the target requirements with a maximum deviation of less than 16%. The neural network-based model can be used in various application scenarios (e.g., low-cost ECC and low-carbon ECC), thus promoting the development of ECC materials in the area of research and engineering application.

Innovative and Sustainable Composite Material for the Seismic and Energetic Upgrade of Historic Masonry Buildings

Usually, energy and structural improvements for historic masonry buildings are addressed separately using distinct methods and protocols. This paper covers an integrated assessment of new composite materials to reduce the seismic vulnerability of historic masonry buildings while complying with sustainable conservation requirements, emissions’ reduction, and energy savings. Firstly, this study focused on selecting suitable thermal mortars that could serve as the base material for the innovative composite. Subsequently, the mechanical characteristics of these mortars were examined by subjecting them to compressive and three-point bending tests. Dynamic thermo-hygrometric simulations were conducted using commercially available software to check the energy performance of the composite material when used on walls of existing masonry buildings. The thermal mortar that exhibited the most favorable mechanical and thermal properties was subsequently reinforced with a basalt fabric. A composite sample was assembled and subjected to direct tensile testing to determine its stress–strain behavior.

Experimental Investigation of the Derivative Cutting When Machining AISI 1045 with Micro-Textured Cutting Tools

In the context of satisfying sustainability requirements nowadays, dry machining is one of the ideal strategies to eliminate the environmental and human health burdens of machining processes. In addition, micro-textured cutting tools are used to improve the performance of dry machining processes. Micro-textures reduce the chip-tool contact length and thus reduce friction and heat, which results in fewer cutting forces and temperature. However, the action of micro-cutting of the bottom side of the chip, which is known as derivative cutting, cuts down the gains of using textured tools, where derivative cutting leads to higher cutting forces, heat, and tool wear. This study aimed to investigate the effects of significant texture design parameters (i.e., micro-groove width) when cutting AISI 1045 steel using different machining parameters (i.e., 75 m/min and 150 m/min of cutting velocity, 0.05 and 0.10 mm/rev of feed). Three different textured cutting tool designs were prepared using the laser texturing technique and then utilized in machining experiments. In addition, the measured machining outputs were forces, power consumption, flank wear, and surface roughness. There were no marks for the derivative cutting when using the textured cutting tool with the narrowest micro-grooves according to the obtained microscopical images after the machining tests. In addition, the textured cutting tool, which included the narrowest micro-grooves, showed better performance compared to the non-textured cutting tool and the other textured tool designs in terms of cutting and feed forces, power consumption, flank tool wear, and surface roughness at the used cutting conditions. This confirmed that the careful optimal design of the micro-textured tools can reduce or eliminate the severity of the derivative cutting, and thus improve the overall machining performance.

Resilient and Sustainable Housing Models against Climate Change: A Review

Most of the world’s population resides in urban areas, and it is expected that this will continue to be the case in the future. These urban areas face enormous challenges such as climate change, economic instability and inequality. Housing is considered a basic unit comprising cities, and, as such, this study contextualized the concepts of urban resilience and sustainability against climate change such that housing models that respond to these concepts could be identified. As a result of an extensive literature review, three resilient housing models and four sustainable housing models are presented and discussed with a focus on the main characteristics necessary for meeting urban resilience and sustainability against climate change. When analyzing the housing models considered resilient, the need to establish housing on safe land stood out and concrete was a common building material among these housing models. In addition, the use of alternative sources of water and energy supply was prioritized. On the other hand, sustainable housing models were developed by local entities and certified by various initiatives. In addition, these models account for the climatic specifications of their location, energy and water efficiency, and quality of the indoor environment, and promote the use of local materials and resources. The use of durable materials was considered a requirement for both resilience and sustainability. The results of this study are a contribution to the process of strengthening housing against the challenge posed by climate change in a timely and adequate manner considering both urban resilience and sustainability aspects.

The effectiveness of performance-based contracting in the defence sector: A systematic literature review

Performance-based contracting in the defence sector, also known as performance-based logistics (PBL), is attracting growing interest from operations and supply management scholars. In the defence sector, PBL entails outsourcing weapon system-related maintenance and logistics activities in such a way that it incentivises suppliers to invest in equipment reliability and process improvements at a reasonable cost. Research has advanced our knowledge of how PBL contracts are designed and implemented, but we still have only limited understanding of PBL evaluation issues, specifically PBL effectiveness and its influencing factors. Focusing on the defence context, we address this knowledge gap through a systematic literature review and synthesis of 45 peer-reviewed articles. We identify 15 factors influencing PBL effectiveness, which are grouped into six categories: governance, supply chain management, defence buyer input, innovation, environmental factors, and resources and capabilities. We extend prior research by developing a classification framework of the factors influencing PBL effectiveness. Further, we leverage defence industry-specific characteristics to suggest avenues for impactful future research through a series of propositions, including the need to examine how political factors influence the effectiveness of performance-based contracting in the defence sector. We also suggest that environmental sustainability and resilience requirements should be included when evaluating the effectiveness of PBL contracts and defence contracting more generally.

Structural Performance of Demountable Hybrid Floor Systems Under Monotonic and Cyclic Loading

AbstractThe building sector is actively researching and reviewing technical solutions for de‐construction, driven by the increasing importance of sustainability requirements, as outlined in the EU Commission's ‘Green Deal,‘ which aims to achieve net‐zero greenhouse gas emissions by 2050. Two key research areas in efficient structural design strategies are the performance of hybrid structures, which combine mechanical properties and architectural appearance of different materials, and the techniques and mechanical properties of connections between structural components that enable deconstruction and reuse. However, there is a scarcity of studies and methods focused on demountable and hybrid structural systems, limiting the understanding of their overall structural performance at a real‐structure floor level. In this paper, a finite element model is presented to conduct a comparative study between the traditional floor system with welded stud connections and the demountable floor system with coupler‐embedded bolted connectors. The numerical results showed that the serviceability loading capacity of the demountable floor system was 8% lower, and the difference in ultimate resistance was further enlarged. Reusing a demountable floor system, analysed in the case study, had little effect on the ultimate resistance, but it is difficult to exclude local plastic deformation after the first life cycles.

Guest Editorial: Brownfield Optimization The Key To Unlocking Sustainable Oil and Gas?

The topic of sustainability within the oil and gas industry has dominated news agendas in recent years. As ‘Net Zero by 2050’ goals loom closer, the sector is under greater pressure than ever to decarbonize operations and source oil and gas via more sustainable methods. With the energy transition continuing at pace, the growth of renewable energy has been exponential. Energy sources such as nuclear and wind are set to account for a greater portion of the energy mix. Renewables expenditure is also expected to double over the next 10 years to more than $1,300 billion per year, and grid expenditure is likely to exceed $1,000 billion per year in 2030. However, oil and gas will undoubtedly play a crucial role in meeting global energy demand for the foreseeable future. A recent industry report highlighted that conventional hydrocarbons are set to comprise 49% of the energy mix in 2050, emphasizing the sustained requirement for traditional hydrocarbons. It is no secret the oil and gas sector is a high producer of carbon emissions, and according to the International Energy Agency, global production, transportation, and processing of oil and gas emitted the equivalent of 5.1 billion tons of CO2 in 2022. That’s almost 15% of total energy-related greenhouse gas emissions. So, how do we as an industry continue to extract this much needed energy source in a more-sustainable manner? Methods to curb this emission are already in practice, with operators utilizing new technology to reduce waste-gas production, return the gas to on-site product streams, and reinject methane into reservoirs. A notable example came from ExxonMobil in January of this year with the company announcing it had stopped routine flaring of natural gas from production in the top US shale basin, using compressors to push natural gas to a pipeline. It has also allocated $17 billion through 2027 to lower its greenhouse gas emissions globally. Electrification is also a hot topic, with operators investigating methodologies for how to reduce emissions from offshore assets. bp, Equinor, and Ithaca Energy recently signed a memorandum of understanding to explore electrification options for their offshore production facilities in the West of Shetland area in the North Sea. Electrification solutions could include power from shore, potentially from onshore wind, or from offshore wind. Full electrification would require in the region of 200 MW of power. If successful, the fields would become the first oil and gas developments on the UK Continental Shelf to be powered by electricity delivering a fully renewable solution. These latest industry moves are bold. They certainly show that much-needed action is now taking place and that industry is responding to social and environmental pressures to make changes.

The energy-food dilemma for utilizing biofuels in low-income communities amidst the Russian–Ukrainian conflict

The Russian–Ukraine war has had and will continue to impact global energy and food security; this will increase the pressure on low-income communities due to rising food costs, as some food was used for energy (i.e. cooking oil). In addition to that, rising energy demand, fuel price increases, the need for energy security, climate change, and means of lowering greenhouse gas emissions are significant considerations in all ethical discussions, particularly when considering the human right to food; there is a tension between the usage of land and availability of water and the human need for fuel, such as biofuel. Although biofuels have the potential to alleviate energy difficulties, producing and consuming such fuels raises social, economic, technological, environmental, and ethical concerns due to ethical aspects such as Rights, Duty, Virtue, Utilitarianism, and Sustainability. Furthermore, all participants bear an ethical responsibility to ensure that biofuels are produced and used appropriately, taking into account citizens’ rights to nourishment, well-being, and employment, the environmental sustainability of such fuels, as well as their capacity to reduce greenhouse gas emissions and the equitable distribution of such fuels’ costs and benefits. Using human food to produce biofuels has raised several issues since it may jeopardize the human right to enough sustenance for healthy living. In contrast, current biofuel production and use do not meet environmental sustainability requirements.

Development of an LCA-based tool to assess the environmental sustainability level of cosmetics products

PurposeThe depletion of natural resources and the downgrading of the environment, driven by globalization and consumerism phenomena, are worldwide pushing the interest in sustainable manufacturing paradigm and environment preservation. It is moreover clear to academia and practitioners that the cosmetics industry needs to update its current operations to face new sustainable requirements and norms due to its ever-growing size and massive consumption of natural resources. Different methodologies, metrics, and indicators have been and are being proposed for solving the complex issues of environmental sustainability evaluation of cosmetics processes and products.MethodsAmong these approaches and methods, product-related assessment tools (e.g., life cycle assessment) are usually more focused on the environmental dimension of sustainability, and they are always based on the life cycle of the product. The core of this paper is on the development of a novel tool to classify cosmetics products based on the results of LCA: the eco-friendliness assessment tool (EFAT). The methodology of the work is structured into 5 main phases: definition of the scientific background of the work, definition of the tool requirements, tool development, testing of the tool, analysis of the results. The eco-friendliness assessment tool proposed is structured into two main parts: (i) process flow 1: environmental impact score and (ii) process flow 2: supplier environmental sustainability assessment.ResultsThe tool has been tested on a cosmetics product manufactured in a cosmetics company located in Italy. The acquisition of raw material process and primary packaging process are the two most critical processes resulting from the impact analysis of LCA methodology. The application of the EFAT tool shows the two possible most sustainable improved scenarios are as follows: (i) exploiting transportation of the primary packaging by sea and (ii) adopting the European location of the primary packaging supplier. The results coming from the tool application allowed the definition of the company product eco-friendliness. The eco-friendliness is symbolized by an alphabetical letter and a color.ConclusionsThe paper proposes a practical tool to assess the environmental sustainability level of cosmetics products, with the intention to overcome two of the main literature gaps found in the state of the art: (i) absence of LCA methodology implementation in the cosmetics industry on makeup products, (ii) absence of tools that rely on the results of the LCA analysis of a cosmetic product for understanding its sustainability level of sustainability.

User Involvement on Air Quality in Incubation Rooms in Banten-Indonesia

Constructing middle-income housing in urban areas can be an effective means of optimizing the environment's carrying capacity and reducing land use. The air quality in Jakarta is an ongoing concern, and it can have significant health implications for those living in housing developments. In high-rise housing structures, air conditioning units are essential for regulating air circulation and minimizing indoor pollutants that can impact neighboring units' comfort levels. This research aims to evaluate the occupants' involvement in implementing indoor air quality (IAQ) sustainability practices in middle-income housing in Jakarta and how it impacts the community. The study identifies the occupants' characteristics, including managers and residents, explores their interactions in adopting healthy living habits, and analyzes their participatory roles in optimizing indoor air quality. The research uses the partial least squares method via SmartPLS for analysis. The findings indicate that both residents and managers must be involved in promoting healthy lifestyles and IAQ in middle-income housing units. As a result, the Jakarta local government should make community engagement programs a mandatory requirement for middle-income housing development regulations to support administrative, technical, and ecological requirements for health sustainability.

Assessing sustainability focus across global banks

Global banks play intermediary and even direct roles in achievement of the UN Sustainable Development Goals (SDGs). However, developmental progress is complex to measure due to siloed, varied and even non-transparent, ambiguous, non-standardized ways of calibration and reporting. This research explores public disclosures (sustainability, CSR, and annual reports, press releases, website, and others) of fifty banks across nine geo-segments over five calendar years (2018–2023). Inductive methods, co-word assessments, content analysis are deployed to develop qualitative commentaries indicating geo-specific performances of the banks. The research findings indicate goal-specific attribution and discovery of motives and initiatives. This validates how motives in embracing the SDGs vary and relate to achievement of – (A) core business objectives; (B) support and financing of other industries, organizations, and governments in sustainable initiatives; and (C) corporate citizenship, altruistic and ethical considerations. Methodological approaches to calibrate findings across seventeen SDGs help identify benchmark practices, understand complementary actions, and required focus for banks and other industries. This is relevant to geo-specific sustainability challenges, trade-offs, and requirements. The findings can guide public policies and regulations, empower banks and other institutions to accelerate awareness and evaluate effectiveness towards sustainable developments.

Production and utilization of the Chlorella vulgaris microalgae biochar as the fuel pellets combined with mixed biomass

The current study focuses on the capability of microalgae biochar as fuel pellets. Additionally, the study aims to investigate the treatment of synthetic saline wastewater through microalgae cultivation, which is an essential tool for meeting the sustainable environment requirements of nations. Microalgae have the tendency to absorb harmful pollutants from wastewater and use them as nutrients for their growth. In this study, Chlorella vulgaris was cultivated in sewage wastewater, and the cultivated samples were collected to produce biochar through a microwave-assisted pyrolysis process. Growing microalgae in wastewater reduces the concentration of ammonia and total phosphorus, and both toxic pollutants are completely absorbed after 60 days of cultivation. The cultivated microalgae underwent pyrolysis to produce biooil, synergetic gas, and biochar. The microwave-assisted pyrolysis process was used to produce the biochar, which was then mixed with agro-waste to form fuel pellets at an equal mass ratio. Three different samples at various concentrations of biochar were examined. Based on the findings, it is evident that the calorific value of the fuel pellets is enhanced upon the addition of biochar. Moreover, there is an increase in the burning time of the pellets made from microalgae-based biochar. Furthermore, microalgae cultivation in wastewater reduced ammonia and total phosphorus content, and the biochar produced from the harvested microalgae improved the ultimate stress, heating value, and bulk density of the pellets. The addition of biochar to the pellets reduced moisture content and increased combustion time, making it a highly justifiable option.

Comparing bio-binders, rubberised asphalts, and traditional pavement technologies

Nowadays pavement technologies must comply with sustainability requirements, including global warming, energy consumption, and quietness. On the one hand, global warming is the most important category of impacts analysed as it is primarily associated with climate change and with intrinsic effects on human health, weather, and natural habitats. The emission of greenhouse gases (GHGs), is essentially related to fuel combustion during construction and transportation operations, but also during the materials production processes. On the other hand, traffic noise is a major concern, being related to premature mortality and years lived with disability.The road industry is focused on developing solutions able to face these issues and in the last years, the use of crumb rubber from end-of-life tyres and the use of binders combined with renewable natural resources (bio-binders) have gained momentum. Despite this, many uncertainties arise when comparing different solutions and this calls for specific comparisons in terms of life cycle assessment (LCA).Based on the above, the objectives of the study described in this paper have been confined to i) comparing rubberized and bio-asphalts, and traditional pavement technologies from a broader perspective, including LCA-based criteria; ii) setting up a method to compare innovative (e.g. green) and traditional pavement technologies; iii) detecting, discussing, and promoting competitive equilibria among pavement technologies.Six different alternative solutions were studied including two reference scenarios (traditional dense-graded and porous asphalt concrete), a solution with the use of crumb rubber, and a solution with a bio-binder.

A methodological framework to create an urban greenway network promoting avian connectivity: A case study of Curitiba City

Integrating landscape models into urban planning can promote the use of green infrastructure tools in cities, which are essential for meeting future sustainability requirements. The city of Curitiba, the capital of Paraná State, Brazil, provides an opportunity to research methodologies related to habitat connectivity in urban areas. Our study aims to propose a network of greenways that connect the most ecologically relevant green areas. Our methodology integrates avian movement and environmental indicators to enhance urban ecology by leveraging the spatial characteristics of the landscape. In designing the path network, we adapted the parameters to fit the minimum cumulative resistance model, which was based on studies of birds in the urban environment and their dispersion behavior. Our findings indicated that impervious surfaces were the predominant land cover class in the city landscape, while larger forest fragments were primarily situated in the south and northwestern regions. By utilizing least-cost paths, we identified twenty-six priority areas that could be connected to form an ecological network spanning the landscape. Our analysis revealed that the path network was more densely distributed in peripheral areas, where the largest habitats were located, primarily within the city's green belt. Regarding land cover classes along the paths, we found that 39% consisted of forest, 25% of impervious surface, 19% of grass, 16% of bare soil, and 1% of water. Despite being highly urbanized, Curitiba possesses significant potential for restoring avian-related functional connectivity through the urban forest. To aid in the recovery and conservation of ecological corridors along the greenways, we developed a set of guidelines. The information gathered from this study may prove useful for future interventions in the city, and the proposed methodology could serve as a model for greenway planning in other urban areas.

Evaluation of Sustainable Slope Stability with Anti-Slide Piles Using an Integrated AHP-VIKOR Methodology

The sustainable design of major civil engineering projects, such as landslide management and slope stability, provides new opportunities for our society regarding the global energy crisis. These sources offer an effective solution to environmental issues and human energy needs. Slope stability, as a critical aspect of ensuring public safety and protection of infrastructure, often leads to disastrous consequences, highlighting the significance of designing effective and sustainable measures to mitigate the risks associated with landslides. Although anti-slide piles have become a widely used method to enhance slope stability, this paper investigates how the Analytic Hierarchy Process (AHP) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) methodologies can be combined to achieve a sustainable design for anti-slide piles, simultaneously considering environmental, economic, safety, and technical factors. Through the integration of AHP-VIKOR and a case study, this paper demonstrates an effective approach to prioritizing sustainability in the design process of anti-slide pile systems, evaluating five main criteria—slope stability, sustainability, anti-slide pile capacity, cost, and ease of construction—and five sub-criteria. The proposed methodology is validated through a case study, wherein various design alternatives for anti-slide piles are evaluated based on sustainable requirements. The results indicate that the slope stability criterion has the highest weight of 0.404, followed by anti-slide pile capacity (0.283), sustainability (0.129), and cost (0.146) criteria. The ease of construction has the lowest weight of 0.038. As a result of the evaluations, it has been seen that, if the sustainability criteria are included in the analyses, the anti-slide pile alternatives are determined in the range of ξ = 0.1–0.3 and s/D = 2.0–3.0, compared to the scenarios where only the economic and technical criteria are satisfied. A pile geometry of diameter, D = 1.00 m, is the most sustainable value within the selected pile spacing intervals, meeting the criteria of slope safety, pile capacity, cost, and ease of construction. This hybrid approach allows for a more balanced consideration of a multi-criteria decision, while considering the sustainability aspects of anti-slide pile selection.

An overview of the integrated biogas production through agro‐industrial and livestock residues in the Brazilian São Paulo state

AbstractRecently, new solutions have arisen to promote bioenergy expansion, some of which meet the requirements of reliability, sustainability, and governance. In Brazil, the Sao Paulo state (SPS) is characterized by strong agro‐industrial and livestock activities, which generates increasing residues in the last years with the potential to produce bioenergy and offer environmental and economic benefits. The Brazilian National Biofuel Policy (Renovabio) has been enhanced to seek sustainable development, encouraging new agribusiness research. Studies have shown that the sugarcane sector, a conventional ethanol and bioelectricity producer, has the greatest potential to produce biogas/biomethane, which can be maximized with the introduction of co‐substrates regionally generated from corn, soy, orange, coffee, poultry, and swine. This overview, based on the main SPS agro‐industrial and livestock residues, shows innovative alternatives for integrating anaerobic co‐digestion (co‐AD) processes through a regional strategy, by providing long‐term revenues and greenhouse gas mitigation, which would also spread the discussion for National and International prospects. This study discusses logistical, political, and financial aspects, revealing a promising business model supported by public policies. However, its feasibility requires a real economic assessment with the inclusion of decarbonization credits, and political subsidies for biomethane as a biofuel under the Renovabio, which will facilitate its insertion into the agro‐industry in the coming years.This article is categorized under: Policy and Economics > Energy Transitions Sustainable Energy > Bioenergy Climate and Environment > Circular Economy Policy and Economics > Regional and International Strategies

Optimization of Capital Structure for Urban Water PPP Projects Using Mezzanine Financing: Sustainable Perspective

An optimal capital structure can minimize financing cost and maximize project value. Most existing studies have focused on the equity-debt financing mode for public–private partnership (PPP) projects, neglecting the usage of mezzanine financing instruments. To bridge the gap, this study constructs a capital structure for urban water PPP projects that uses mezzanine financing called the Urban Water Project Mezzanine Financing (UWPMF) mode. Based on the requirements of sustainability, qualitative and quantitative methods are comprehensively adopted and validate the model using a PPP sewage treatment project in China. The contributions of the study are twofold. First, the introduction of a mezzanine financing tool in the context of a specific industry enriches theoretical research on PPP project financing. Second, sustainability data is included in the capital structure optimization for specific types of PPP projects, providing reference values for promoting the realization of the sustainability goals of PPP projects.