• Energy Research
• engineering and technology close
• 12. Responsible consumption close
• BR close
• MX close
• CO close

Abstract This paper aims to investigate sustainable waste management solutions for the city of Rio de Janeiro in Brazil, based on a life cycle approach. The Life Cycle Assessment (LCA) was performed by using the LCA-IWM methodology. The model was adapted to the Brazilian solid waste context and to the local characteristics, including waste composition, electricity mix and regulations. The annual amount of waste generated was the functional unit adopted. Eight municipal solid waste management strategies were evaluated. Scenarios including mixed waste collection and source separated collection as well as materials recovery and energy from waste were investigated. Scenarios were ranked based on the LCA results. Sensitivity analysis was carried out by varying the electricity mix. The results indicate that the current situation of municipal solid waste (MSW) in Rio de Janeiro presents the worst performance in terms of aggregated environmental burdens, indicating the urgency for implement new strategies toward a more environmentally friendly and sustainable MSW management system. It is noted that the better LCA performances were obtained in scenarios with high separately collection rates. Among them, the scenario based on recyclables recovery and anaerobic digestion shows to be a promising strategy to improve environmental sustainability. Sensitivity analysis demonstrates that the ranking of scenarios was not affected by changes in the electricity mix. From the results, the investment in source separated waste collection and materials recovery is the most environmentally friendly MSW strategy for Rio de Janeiro. In addition, scenarios with an emphasis in materials recovery presented higher environmental benefits than the alternatives focused on energy generation.

This work evaluates, for the first time, the possibility of producing multifunctional alkali-activated composites combining ultra-low density, low thermal conductivity, high acoustic absorption, and good moisture buffering capacity. The composites were prepared using cork as a lightweight aggregate. This novel material might promote energy savings and tackle the CO2 emissions of the building sector, while simultaneously improve the comfort for inhabitants (e.g. humidity levels regulation and sound pollution reduction). The composites apparent density (as low as 168 kg/m3) and thermal conductivity (as low as 68 mW/m K) are amongst the lowest ever reported for alkali-activated materials (AAM) composites and foams, while their sound absorption ability is comparable to the best performing AAM foams reported to date, but in addition these eco-friendly composites also show good ability to passively adjust the humidity levels inside buildings. The multifunctional properties shown by the cork – AAM composites set them apart from other conventional building materials and might contribute to the global sustainability of the construction sector. Peer Reviewed

Plastic waste is an issue of global concern because of the environmental impact of its accumulation in waste management systems and ecosystems. Biodegradability was proposed as a solution to overcome this problem; however, most biodegradable plastics were designed to degrade under aerobic conditions, ideally fulfilled in a composting plant. These new plastics could arrive to anaerobic environments, purposely or frequently, because of their mismanagement at the end of their useful life. This review analyzes the behavior of biodegradable and conventional plastics under anaerobic conditions, specifically in anaerobic digestion systems and landfills. A review was performed in order to identify: (a) the environmental conditions found in anaerobic digestion processes and landfills, as well as the mechanisms for degradation in those environments; (b) the experimental methods used for the assessment of biodegradation in anaerobic conditions; and (c) the extent of the biodegradation process for different plastics. Results show a remarkable variability of the biodegradation rate depending on the type of plastic and experimental conditions, with clearly better performance in anaerobic digestion systems, where temperature, water content, and inoculum are strictly controlled. The majority of the studied plastics showed that thermophilic conditions increase degradation. It should not be assumed that plastics designed to be degraded aerobically will biodegrade under anaerobic conditions, and an exact match must be done between the specific plastics and the end of life options that they will face.

Abstract In order to improve the accuracy, validity, reliability and reproducibility of reported power conversion efficiencies for solar cells, the journal, Solar Energy Materials and Solar Cells (SOLMAT), wishes to define how power conversion efficiencies should be reported. This expands upon what is specified in our Guide for Authors. This editorial also serves as a guide on how efficiency data should be checked within the reporting laboratory before sending cells or materials for testing at an independent laboratory. The threshold where the accuracy of efficiency values is important to the journal is whenever power conversion efficiencies require external quantum efficiencies (EQE) values above 50% over a large range of wavelengths or when reported power conversion efficiencies exceed 2.5%. Extra care should be taken in submitted manuscripts to document the measurement's quality, relevance and independent verification.

AbstractBrazilian countryside has well‐defined dry seasons that are mainly characterized by low relative humidity. The warm, dry air provides a thermal cooling effect when it interacts with wet porous structures (psychrometric effect). Depending on temperature conditions and relative humidity, it is possible to achieve up to 18.0 K reduction in the temperature of the structure, caused by water evaporation. Thus, the objective of this study was to propose and numerically investigate a low cost and sustainable air conditioning system by combining the potential of warm, dry air and characteristics of the flow within cyclones covered with thin wet cotton fabric. A validated mathematical model was developed, and the numerical results indicate that the cyclonic‐psychrometric system can provide up to 7.0 K reduction in a 20.0 m2 room on a warm day (305.0 K) with low relative humidity (20.0%). Energy balances and technical estimates showed that the electric power consumed by the proposed system would represent only 19.8% of the power required by a conventional 18,000 Btu air conditioner to promote the same reduction of temperature. This energy‐saving would have a direct and positive impact on the budget of users, especially those with low income and that live in dry regions.

Les développements des systèmes de transport, les changements dans les tendances de consommation et des conditions telles que la COVID-19 ont augmenté à la fois la demande et la charge du transport de marchandises. Étant donné que diverses entreprises transportent des marchandises dans le monde entier pour évaluer la durabilité, la vitesse et la résilience des systèmes de transport de marchandises, des systèmes de mesure de la fluidité des données et du fret sont nécessaires. Dans cette étude, un modèle de prise de décision intégré est proposé pour donner la priorité aux alternatives de mesure de la fluidité du fret. Le modèle proposé est composé de deux étapes principales. Dans la première étape, la méthodologie logarithmique des poids additifs (LMAW) basée sur les normes de Dombi est utilisée pour trouver les poids des critères. Dans la deuxième phase, une évaluation étendue basée sur la méthode de la distance de la solution moyenne (EDAS) avec Dombi onction pour l'agrégation est présentée pour déterminer les résultats finaux de classement des alternatives. Trois alternatives de mesure de la fluidité du fret sont proposées, à savoir ne rien faire, intégrer les activités de fret dans Metaverse pour mesurer la fluidité et former une gouvernance mondiale des activités de fret pour mesurer la fluidité à partir des données disponibles. Treize critères, qui sont regroupés sous quatre aspects principaux à savoir la technologie, la gouvernance, l'efficacité et la durabilité environnementale, et une étude de cas au cours de laquelle un cadre de base est formé pour que les experts évaluent les alternatives compte tenu des critères utilisés dans le processus décisionnel multicritères. Les résultats de l'étude indiquent que l'intégration des activités de fret dans Metaverse pour mesurer la fluidité est l'alternative la plus avantageuse, alors que ne rien faire est la moins avantageuse. Los desarrollos en los sistemas de transporte, los cambios en las tendencias de consumismo y condiciones como el COVID-19 han aumentado tanto la demanda como la carga en el transporte de mercancías. Dado que varias empresas transportan mercancías en todo el mundo para evaluar la sostenibilidad, la velocidad y la resistencia de los sistemas de transporte de mercancías, se necesitan sistemas de medición de datos y fluidez de la carga. En este estudio, se propone un modelo integrado de toma de decisiones para priorizar las alternativas de medición de la fluidez de la carga. El modelo propuesto se compone de dos etapas principales. En la primera etapa, se utiliza la Metodología Logarítmica de Pesos Aditivos (LMAW) basada en normas Dombi para encontrar los pesos de los criterios. En la segunda fase, se presenta una Evaluación extendida basada en el método de Distancia de la Solución Media (EDAS) con Dombi unción para la agregación para determinar los resultados finales de clasificación de las alternativas. Se proponen tres alternativas de medición de la fluidez de la carga, a saber, no hacer nada, integrar las actividades de carga en Metaverse para medir la fluidez y formar una gobernanza global de las actividades de carga para medir la fluidez a través de los datos disponibles. Trece criterios, que se agrupan en cuatro aspectos principales: tecnología, gobernanza, eficiencia y sostenibilidad ambiental, y un estudio de caso en el que se forma un marco básico para que los expertos evalúen las alternativas considerando que los criterios se utilizan en el proceso de toma de decisiones multicriterio. Los resultados del estudio indican que integrar las actividades de carga en Metaverso para medir la fluidez es la alternativa más ventajosa, mientras que no hacer nada es la menos ventajosa. Developments in transportation systems, changes in consumerism trends, and conditions such as COVID-19 have increased both the demand and the load on freight transportation. Since various companies are transporting goods all over the world to evaluate the sustainability, speed, and resiliency of freight transportation systems, data and freight fluidity measurement systems are needed. In this study, an integrated decision-making model is proposed to advantage prioritize the freight fluidity measurement alternatives. The proposed model is composed of two main stages. In the first stage, the Dombi norms based Logarithmic Methodology of Additive Weights (LMAW) is used to find the weights of criteria. In the second phase, an extended Evaluation based on the Distance from Average Solution (EDAS) method with Dombi unction for aggregation is presented to determine the final ranking results of alternatives. Three freight fluidity measurement alternatives are proposed, namely doing nothing, integrating freight activities into Metaverse for measuring fluidity, and forming global governance of freight activities for measuring fluidity through available data. Thirteen criteria, which are grouped under four main aspects namely technology, governance, efficiency, and environmental sustainability, and a case study at which a ground framework is formed for the experts to evaluate the alternatives considering the criteria are used in the multi-criteria decision-making process. The results of the study indicate that integrating freight activities into Metaverse for measuring fluidity is the most advantageous alternative, whereas doing nothing is the least advantageous one. أدت التطورات في أنظمة النقل، والتغيرات في اتجاهات النزعة الاستهلاكية، وظروف مثل COVID -19 إلى زيادة الطلب والحمل على نقل البضائع. نظرًا لأن العديد من الشركات تنقل البضائع في جميع أنحاء العالم لتقييم استدامة وسرعة ومرونة أنظمة نقل البضائع، فهناك حاجة إلى أنظمة قياس سيولة البيانات والشحن. في هذه الدراسة، يُقترح نموذج متكامل لصنع القرار للاستفادة من إعطاء الأولوية لبدائل قياس سيولة الشحن. يتكون النموذج المقترح من مرحلتين رئيسيتين. في المرحلة الأولى، يتم استخدام منهجية لوغاريتمية الأوزان المضافة (LMAW) القائمة على معايير دومبي لإيجاد أوزان المعايير. في المرحلة الثانية، يتم تقديم تقييم موسع يعتمد على طريقة المسافة من الحل المتوسط (EDAS) مع Dombi unction للتجميع لتحديد نتائج الترتيب النهائي للبدائل. يتم اقتراح ثلاثة بدائل لقياس سيولة الشحن، وهي عدم القيام بأي شيء، ودمج أنشطة الشحن في ميتافيرس لقياس السيولة، وتشكيل حوكمة عالمية لأنشطة الشحن لقياس السيولة من خلال البيانات المتاحة. ثلاثة عشر معيارًا، تم تجميعها تحت أربعة جوانب رئيسية وهي التكنولوجيا والحوكمة والكفاءة والاستدامة البيئية، ودراسة حالة يتم فيها تشكيل إطار أرضي للخبراء لتقييم البدائل مع مراعاة استخدام المعايير في عملية صنع القرار متعددة المعايير. تشير نتائج الدراسة إلى أن دمج أنشطة الشحن في ميتافيرس لقياس السيولة هو البديل الأكثر فائدة، في حين أن عدم القيام بأي شيء هو البديل الأقل فائدة.

Brazil uses taxes, subsidies, and blending mandates as policy instruments to manage and stabilize its transportation fuel markets. The fuel sector has been very dynamic in recent years due to frequent policy adjustments and variable market conditions. In this paper, we use a price endogenous economic simulation model to analyze the impacts of such policy adjustments under various challenging conditions in the global ethanol and sugar markets. Our analysis specifically focuses on Brazilian producers' supply responses, consumers' driving demand and fuel choice, ethanol trade, land use, greenhouse gas emissions, and social welfare. The model results show that (i) under a low ethanol blending rate, conventional vehicles would be driven significantly less while flex-fuel and ethanol-dedicated vehicles would not be affected significantly; (ii) lowering the fuel taxes adversely affects the competitiveness of sugarcane ethanol against gasoline blends, thus lowering producers' surplus; and (iii) while a reduction in fuel taxes is advantageous in terms of overall social welfare, it has serious environmental impacts by increasing the GHG emissions from transportation fuels consumed in Brazil.

AbstractThe anaerobic digestion of industrial wastes produces a biogas that is an alternative to the use of fossil fuels for energy production. At the end of this process, the stabilized biomass presents high levels of nutrients, which can be used both as biofertilizers in agriculture and for the biodegradation of contaminants in the soil through improvement of the microbiota. Thus, this study aimed to evaluate biogas production by industrial wastes and to use the biofertilizer for the bioremediation of soils previously contaminated with gasoline. The biomass (420 mL) generated approximately 10 liters (L) of methane and 3 L of other gases. Anaerobic incubation reduced total and volatile solids, as well as biochemical oxygen demand, chemical oxygen demand, and the carbon and nitrogen contents of the biomass. The bioremediation experiment showed that 15 days after contamination with gasoline, the addition of the biofertilizer improved the degradation efficiency of monoaromatic hydrocarbons; however, the degradation of polyaromatic hydrocarbons was less time efficient. So, we conclude that the anaerobic incubation of industrial wastes generates a high amount of biogas, and that biofertilizer deposition into contaminated soil does not affect the efficiency of the degradation of aromatic hydrocarbons after 30 days. Novelty or significance: Anaerobic incubation of industrial wastes generates a high calorific value gas, which can be used as an alternative source of energy. And, the resulting biomass, called biofertilizer, can be used to remediate soils contaminated with hydrocarbons.

AbstractFly ash is currently a problem in different companies, mainly in thermoelectric plants, which must follow a production and consumption model that involves reusing, renewing, and recycling, thus contributing to the circular economy. This work aims to evaluate the reactivity and compressive strength of different types of ashes in concrete monoliths. For this purpose, sugarcane bagasse (SCBA), bituminous coal (BC), and untreated hazardous waste (RUD) were evaluated as replacements for cement. Monoliths and mortars have been manufactured in different mixtures, taken to a curing room, and their compressive strength and reactivity have been determined at different times (up to 28 days for the monoliths and up to 90 for the mortars), mainly in order to check the formation of calcium silicate hydrate (CSH) gels. In the monolith tests, the best performances have been with SCBA and BC, which have been used for the manufacture of the mortars. On day 56, the behavior of the replacement of 30% fly ash (15% BC:15% SCBA) presents a type H mortar behavior, with better results than the control. By day 90, all replacements had the same resistance as M mortars and even higher resistances than the control. This demonstrates the feasibility of its use in the production of Portland cement for the manufacture of low‐performance inputs. This implies the possible reduction of impacts, both in waste disposal sites and in emissions caused by the construction industry, thus contributing to the circular economy.

Various government agencies around the world have proposed vegetable oils and their conversion to biodiesel as a renewable alternative to fossil fuels. Due to its adaptability to marginal soils and environments, the cultivation of Jatropha curcas is frequently mentioned as the best option for producing biodiesel. In the present work the current situation of proven and potential reserves of fossil fuel, and the production and consumption model for the same are analyzed, in order to later review the sustainability of the production process which begins with the cultivation of J. curcas, and culminates with the consumption of biodiesel. A review of the following topics is proposed in order to improve the sustainability of the process: areas destined for cultivation, use of external (chemical) inputs in cultivation, processes for converting the vegetable oil to biodiesel, and, above all, the location for ultimate consumption of the biofuel.