• Energy Research

In recent years, waste management systems have been evaluated using a life cycle assessment (LCA) approach. A main shortcoming of prior studies was the focus on a mixture of waste with different characteristics. The estimation of emissions and consumptions associated with each waste fraction in these studies presented allocation problems. Waste-to-energy (WTE) incineration is a clear example in which municipal solid waste (MSW), comprising many types of materials, is processed to produce several outputs. This paper investigates an approach to better understand incineration processes in Spain and Portugal by applying a multi-input/output allocation model. The application of this model enabled predictions of WTE inputs and outputs, including the consumption of ancillary materials and combustibles, air emissions, solid wastes, and the energy produced during the combustion of each waste fraction.

The big challenge of the next decades is meeting the global nutritional demand, while reducing the pressure on food resources and the GHG emissions. In this regard, the overall goal consists of redesigning the food systems and promoting sustainable dietary patterns is a crucial aspect. This article focuses on reviewing the state-of-the-art of the combined Life Cycle Assessment (LCA) and the Water-Energy-Food (WEF) Nexus approach in assessing the effects of diet transitions. Diet LCAs differ in methodology, design, and assessed environmental impacts. The WEF nexus, which aims at finding synergies and trade-offs between the water, energy, and food resources systems, has been applied to different contexts and levels. However, a limited number of nexus methods have been developed at the food and diet levels, and no commonly recognizable methodology for the nexus assessment has been achieved. An integrated LCA and WEF Nexus approach can be a decisive tool to improve the understanding of the interconnections in the nexus, as it enables the consideration of entire supply chains. This study is part of the Ceres-Procon Project: Food production and consumption strategies for climate change mitigation (CTM2016-76176-C2-2-R) (AEI/FEDER, UE), financed by the Spanish Ministry of Economy and Competitiveness, which aims to determine strategies to improve the sustainability of current food production and consumption.

This paper gives an overview of main food supply chain stakeholders and their role in achieving the UN Sustainable Development Goals (SDGs). As this supply chain is global, playing a significant role in feeding the world, a deeper analysis of 17 SDGs, their targets and indicators reveals numerous direct and indirect connections with various SDGs. To perform such an overview, the authors investigated the link between the main stakeholders of the chain (farmers, food processors, food traders and consumers) with UN SDGs. In parallel, the authors explored the roles of policymakers, inspection services, certification bodies and academia in supporting these SDGs. In spite of numerous papers, calculations and estimations, discussion and media coverage, the authors believe that only the tip of the iceberg has been revealed. Based on this overview, the authors emphasize SDG 2—Zero Hunger and SDG 12—Responsible Consumption and Production as the most dominant for the food supply chain. In parallel, the achievement of SDG 17—Partnerships for the Goals will enable deeper intertwining of the goals and all stakeholders in the food supply chain continuum. Additional efforts are needed to pave the way for fulfilling the targets of the UN SDGs and exceeding expectations of all stakeholders.

Annually, around 7.7 billion passengers travel by plane. The menus served during the flight are quite similar between different airlines and are composed of the food itself, packaging (paper envelopes, film, etc.) and tableware (mainly trays, plates, glasses, cups and cutlery). In 2016, 1522 tonnes of tourist class menus were served in Iberia aircrafts landing at Madrid Barajas airport in Spain. From this amount, 51% by weight was packaging and tableware, and the remaining 49% food. As changes in the food has little room for maneuver, since the same amount would be delivered regardless how it is served, this study focus on the possibilities of packaging and tableware to reduce GHG emissions. The assessment has been done using life cycle assessment methodology (LCA) in order to identify the hotspots along the whole life cycle of packaging and tableware items. The case study chosen was the catering service of Iberia, the national airline of Spain. The functional unit used was "the service of 1,000 tourist class menus on Iberia flights that landed in Madrid in 2016". The results show that the impacts of reusable and single use items take place at different stages of their life cycles. For reusable ones, 76% of the impact is produced during the flight phase, meanwhile, for single use ones, 53% of the impact comes from the production stage. Variables such as material, weight and the number of reuses can greatly influence greenhouse gas (GHG) emissions. From the results of the analysis some eco-design strategies has been proposed and analysed. The paper reveals that the lighter single-use packaging and tableware for airline catering are less harmful under a life cycle perspective become.

L'analyse du cycle de vie (ACV) est un outil puissant pour prendre des décisions éclairées en matière d'environnement parmi les alternatives de produits et de processus. Les résultats de l'ACV reflètent les contributions de l'étape du processus à plusieurs impacts environnementaux, qui devraient être mutuellement comparables pour aider au processus de prise de décision. Les indices environnementaux agrégés permettent de traduire cet ensemble de métriques en un score final, en définissant les poids attachés aux impacts. Les valeurs de pondération reflètent la pertinence correspondante attribuée à chaque impact environnemental. Les schémas de pesage actuels sont basés sur une pré-articulation des préférences, sans tenir compte des caractéristiques spécifiques du système à l'étude. Cet article présente une méthodologie qui combine la méthodologie de l'ACV et l'optimisation de la programmation linéaire pour déterminer les actions d'amélioration de l'environnement qui conduisent à une production plus durable. L'ACV a été appliquée en utilisant la méthodologie d'évaluation de la durabilité environnementale pour obtenir deux principaux indices : les ressources naturelles (NR) et les charges environnementales (EB). Les indices normalisés ont été optimisés pour déterminer l'articulation optimale des facteurs de pondération qui conduisent à un indice mondial de durabilité environnementale optimisé. La méthodologie proposée a été appliquée à un secteur alimentaire, en particulier à l'industrie de la conserve d'anchois dans la région de Cantabrie (nord de l'Espagne). En maximisant la fonction objective composée des variables NR et EB, il est possible de trouver l'articulation optimale des poids qui identifient les meilleures options environnementales durables. Cette étude prouve que l'ACV peut être appliquée en combinaison avec des outils de programmation linéaire dans le cadre du processus décisionnel dans le développement de processus et de produits plus durables. La evaluación del ciclo de vida (ACV) es una herramienta poderosa para respaldar las decisiones informadas sobre el medio ambiente entre las alternativas de productos y procesos. Los resultados del ACV reflejan las contribuciones de la etapa del proceso a varios impactos ambientales, que deben ser comparables entre sí para ayudar en el proceso de toma de decisiones. Los índices ambientales agregados permiten la traducción de este conjunto de métricas en una puntuación final, al definir los pesos adjuntos a los impactos. Los valores de ponderación reflejan la relevancia correspondiente asignada a cada impacto ambiental. Los esquemas de pesaje actuales se basan en la pre-articulación de preferencias, sin considerar las características específicas del sistema en estudio. Este trabajo presenta una metodología que combina la metodología ACV y la optimización de la programación lineal para determinar las acciones de mejora ambiental que conducen a una producción más sostenible. El ACV se aplicó utilizando la metodología de evaluación de la sostenibilidad ambiental para obtener dos índices principales: recursos naturales (NR) y cargas ambientales (EB). Los índices normalizados se optimizaron para determinar la articulación óptima de los factores de ponderación que conducen a un Índice de Sostenibilidad Ambiental global optimizado. La metodología propuesta se aplicó a un sector alimentario, en particular, a la industria conservera de anchoas en la región de Cantabria (norte de España). Al maximizar la función objetivo compuesta por variables NR y EB, es posible encontrar la articulación óptima de pesos que identifique las mejores opciones ambientales sostenibles. Este estudio demuestra que el ACV se puede aplicar en combinación con herramientas de programación lineal como parte del proceso de toma de decisiones en el desarrollo de procesos y productos más sostenibles. Life cycle assessment (LCA) is a powerful tool to support environmental informed decisions among product and process alternatives. LCA results reflect the process stage contributions to several environmental impacts, which should be made mutually comparable to help in the decision-making process. Aggregated environmental indexes enable the translation of this set of metrics into a one final score, by defining the attached weights to impacts. Weighting values reflect the corresponding relevance assigned to each environmental impact. Current weighing schemes are based on pre-articulation of preferences, without considering the specific features of the system under study. This paper presents a methodology that combines LCA methodology and linear programming optimisation to determine the environmental improvement actions that conduct to a more sustainable production. LCA was applied using the environmental sustainability assessment methodology to obtain two main indexes: natural resources (NR) and environmental burdens (EB). Normalised indexes were optimised to determine the optimal joint of weighting factors that lead to an optimised global Environmental Sustainability Index. The proposed methodology was applied to a food sector, in particular, to the anchovy canning industry in Cantabria Region (Northern Spain). By maximising the objective function composed of NR and EB variables, it is possible to find the optimal joint of weights that identify the best environmental sustainable options. This study proves that LCA can be applied in combination with linear programing tools as a part of the decision-making process in the development of more sustainable processes and products. تقييم دورة الحياة (LCA) هو أداة قوية لدعم القرارات البيئية المستنيرة بين بدائل المنتجات والعمليات. تعكس نتائج تحليل دورة الحياة مساهمات مرحلة العملية في العديد من الآثار البيئية، والتي يجب أن تكون قابلة للمقارنة المتبادلة للمساعدة في عملية صنع القرار. تتيح المؤشرات البيئية المجمعة ترجمة هذه المجموعة من المقاييس إلى درجة نهائية واحدة، من خلال تحديد الأوزان المرفقة للتأثيرات. تعكس قيم الترجيح الأهمية المقابلة المخصصة لكل تأثير بيئي. تستند مخططات الوزن الحالية إلى التفصيل المسبق للتفضيلات، دون مراعاة السمات المحددة للنظام قيد الدراسة. تقدم هذه الورقة منهجية تجمع بين منهجية تقييم دورة الحياة وتحسين البرمجة الخطية لتحديد إجراءات التحسين البيئي التي تؤدي إلى إنتاج أكثر استدامة. تم تطبيق تقييم دورة الحياة باستخدام منهجية تقييم الاستدامة البيئية للحصول على مؤشرين رئيسيين: الموارد الطبيعية (NR) والأعباء البيئية (EB). تم تحسين المؤشرات المعيارية لتحديد المفصل الأمثل لعوامل الترجيح التي تؤدي إلى تحسين مؤشر الاستدامة البيئية العالمي. تم تطبيق المنهجية المقترحة على قطاع الأغذية، على وجه الخصوص، على صناعة تعليب الأنشوجة في منطقة كانتابريا (شمال إسبانيا). من خلال تعظيم الوظيفة الموضوعية المكونة من متغيرات NR و EB، من الممكن العثور على المفصل الأمثل للأوزان التي تحدد أفضل الخيارات البيئية المستدامة. تثبت هذه الدراسة أنه يمكن تطبيق تحليل دورة الحياة جنبًا إلى جنب مع أدوات البرمجة الخطية كجزء من عملية صنع القرار في تطوير عمليات ومنتجات أكثر استدامة.

Dietary choices, a main driver of food production, play a significant role within the climate change arena. Consequently, there is a growing trend on publishing research assessing the environmental impacts of diets and dietary shifts, mainly following the life cycle assessment (LCA) methodology. However, several methodological issues still bring a challenge, especially in the definition of the function and the quantification of the functional unit (FU). The FU is the reference unit of an LCA study, and it is the basis for allowing comparison among different systems. This short communication defines the function of diets as the supply of the daily required amount of calories and nutrients, and it proposes a novel FU that accounts for the energy intake and the nutritional quality of the diet. In order to compare the performance of the proposed FU to the most commonly ones used for diet LCAs (mass-based and isocaloric), dietary scenarios within the Spanish context are assessed. On the one hand, using a mass-based FU, greenhouse gas (GHG) emissions are underestimated, since the nutrition properties of food are not considered, and, on the other hand, the isocaloric substitution does not allow comparison among diets with different levels of energy intake. In contrast, the proposed caloric- and nutrient-corrected FU allows to compare diets that differ in energy and nutritional quality in a fairer way. Finally, it is recommended to use this FU for future diet LCAs.

Waste collection presents a significant influence in the environmental sustainability of municipal solid waste (MSW) management. Conventional door-to-door collection consumes high amounts of fuel for waste transportation, thus generating significant direct greenhouse gas emissions (GHG). Pneumatic collection emerges as an alternative to conventional trucking system, comprised by an underground network of long distance pipelines that carries MSW fractions to a central collection plant where the waste is collected and compacted. Such systems represent a way of arranging waste collection in densely populated urban areas and have recently been used in the design of smart cities to control waste flows. While this technology apparently reduces direct air emissions, suffers from large energy demand derived from vacuum production for waste suction. This work compares both conventional door-to-door and pneumatic collection systems from a life cycle approach, obtaining that the latter accounts for 5 and 3 times more energy demand and CO2-eq. emissions than conventional collection, respectively. Results suggests that the electricity consumption and the origin of electricity have a significant influence on the results, since vacuum production is responsible for more than 99 % of the total impacts for pneumatic scenario, while diesel for trucking accounts to around 70 % of the conventional system impacts. Greener electricity mixes and less energy consuming materials are required in order to ensure the environmental sustainability of pneumatic systems. The authors are grateful for the funding of the Spanish Ministry of Economy and Competitiveness through the Ceres-Procom: Food production and consumption strategies for climate change mitigation (CTM2016-76176- C2-1-R) (AEI/FEDER, UE). The authors wish to extend their acknowledgment to all people involved in the LIFE FENIX Project, as well as the European LIFE Financing Programme. In addition, they want to acknowledge the support of The Circular Lab founded by Ecoembes.