Multi-objective optimization of residential multifamily buildings to minimize cooling and heating simultaneously

Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminan

Public bus transportation system environmental impact projections regarding different policy scenario : A LCA study

Urban activities, such as transportation, are responsible for a large portion of energyrelated CO2 emissions. As the need for sustainable urban development increases, decision-makers embrace Life Cycle Assessment (LCA) as a reliable tool capable of generating scientifically based information on environmental impacts. However, there is still a lack of an analysis standard regarding the particularities of urban systems. Therefore, this research aims to define current and future environmental profiles, considering a case study of the public transport system in Porto Alegre, considering specificities of the urban context and different public policy scenarios through LCA. These results show that, although the transportation system management relies on the municipalities, the higher significance of environmental impacts depend on a national policy for using biodiesel in the diesel sold, which could lead to an increase of, for example, up to 9.4% of CO2 emissions from 2017 (baseline) to 2030. Finally, it is perceivable that to conduct a LCA to support decision-making in public urban services, a detailed approach is needed considering that technological variables interact with the territorial context and policy changes

Potential use of environmental product declaration to support green public procurement in civil construction

As compras públicas movimentam quantia considerável de recursos financeiros e têm o potencial de induzir práticas mais sustentáveis. Entretanto, permanecem barreiras para a sua efetiva implementação. O Programa das Nações Unidas para o Meio Ambiente aponta que um instrumento para auxiliar as compras públicas verdes (CPV) são fichas com informações ambientais, que facilitam a escolha e comparação entre alternativas e podem ser baseadas em técnicas de gestão ambiental como a avaliação do ciclo de vida (ACV) e/ou em declarações ambientais de produto (DAP). O objetivo deste artigo é explorar a abordagem do ciclo de vida nas CPV por meio da análise de DAP, e como suas informações podem integrar um instrumento para a construção civil. O trabalho conta com quatro etapas: análise do contexto; avaliação da estrutura das DAP; identificação das barreiras e oportunidades; investigação das DAP em CPV. Observa-se que o emprego das DAP nas fichas facilita o processo de elaboração e atualização delas, pois elas permitem a comparação entre produtos e a análise do equivalente ambiental, enquanto a ACV garante respaldo científico. Os resultados da revisão crítica mostram, ainda, que CPV são incipientes no contexto brasileiro, mas podem ser expandidas através do instrumento proposto no presente trabalho.Public Procurements move a considerable amount of financial resources and has the potential to induce more sustainable practices. However, there are barriers to the effective implementation of those practices. One of the tools recommended by the United Nations Environment Program (UNEP) to assist Green Public Procurement (GPP) are sheets with environmental information, as they help in the choice and comparison between alternatives and can be based on tools such as Life Cycle Assessment (LCA) and/or Environmental Product Declarations (EPD). The aim of this article is to explore the life cycle approach in GPP by analysing EPDs and how their information can feed the sheets for civil construction. This work was carried out in four steps: context analysis; evaluation of the structure of EPDs; identification of barriers and opportunities; investigation of EPDs in GPP. The study showed that the use of EPDs in the sheets helps the process of developing and updating them, as they allow comparisons to be made between products and the analysis of the environmental equivalent, while the LCA guarantees scientific support. The results of the critical review show the use GPP is still incipient in Brazil, but that it can be expanded through the tool proposed in this paper

Sensitivity Analysis of Life Cycle impacts distribution methods choice applied to silica fume production

The construction sector is known as an important consumer of natural resources. The use of by-products from different production chains in the sector is encouraged, promoting a reduction in the extraction of natural resources, reducing the need for residues disposal and enhancing circularity. Silica fume is a by-product from the smelting process in the silicon and ferrosilicon industry, commonly used as concrete supplementary cementitious material, which provides chemical and physical effects on concrete microstructure. When LCA evaluation is conducted, different impact distribution models may be applied to assess the potential impact of the by-productss. Although their benefits are recognized, some studies still report them as burden free, having no allocated impacts . Thereby, the aim of this paper is to evaluate the differences in silica fume life cycle impacts by analyzing three scenarios from cradle to gate, considering the modeling procedures described by ISO 14040, the Cut-off model from Ecoinvent version 3.3 and the impact assessment method CML v.4.4, according to the CEN EN 15804 recommended categories. Results enhance the understanding regarding model selection and demonstrate that the selection of the proper distribution model is key, considering that this may lead to important differences in the results

Comparison and analysis of product stage and service life uncertainties in life cycle assessment of building elements

Life cycle assessment (LCA) has the potential to inform building decisions from the planning process to conceptual design. As such, there is intrinsic uncertainty that needs to be explored further to allow for proper decisions to be made. These uncertainties may be related to parameter definition, such as life cycle inventory or model as service life definition. This paper aims to analyze the influence of two recognized sources of uncertainties in LCA of buildings: product stage uncertainties and uncertainties from SL during the use stage. The Monte Carlo simulation method is applied to conduct uncertainty analysis of the LCA results of four building elements, namely, external cement plaster, external clay brick wall, external painting and internal painting. The functional unit is 1 m2 of each building element. Three different building reference study periods are considered: 50, 120 and 500 years. A global warming potential impact category is chosen since it is one of the most significant indicators for climate change mitigation strategies. Results indicate that SL uncertainties are greater than product stage uncertainties for the four building elements analyzed. Furthermore, based on the findings from this study, distribution choice influences the uncertainty analysis results in Monte Carlo simulation. Standardizing modeling of SL in the LCA of buildings could guide building LCA practitioners and researchers and lead to more comparable results

Environmental assessment of urban public transport's shift from conventional to electric buses : a case study

The number of Life Cycle Assessment studies in urban public transportation focusing on modals that aim to reduce global warming impacts has been increasing significantly in the last few years. These studies suggest that the insertion of green modals on local public transportation systems could be a solution to reach sustainable development. However, the impact of this insertion in developing countries is not clear yet. Then, our main objective is to evaluate the environmental impact of an emerging city’s public transportation system, considering different public policies. Consequently, we conducted a Life Cycle Assessment study considering the transitions from Diesel to biodiesel buses and electric buses from 2020 to 2030. Three scenarios were performed, with the following criteria: battery changes, the increase of biodiesel percentage used in the fuel mix, and buses’ expected average lifespan transitioning to electric vehicles. The results show a decrease in impact by 2030 in analysed scenarios. They may support policymakers to decide whether to focus on a short-term or long-term transport policy to reduce the fleet’s sustainable impact. Particularly, electric buses have emerged as an option to reduce environmental impacts in the public transportation system in Porto Alegre, Brazil

Seleção dos agregados para produção de concreto de cimento branco

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Life Cycle Assessment applied to construction and demolition waste treatment : proposal of a Brazilian scenario

Important amounts of construction and demolition wastes (CDW) are currently generated in several countries. Considering the correct management of this kind of residue, and the search for its noblest use, several studies have focused on the environmental potential impacts from CDW management. Life Cycle Assessment (LCA) is often used to investigate the potential environmental impacts over the life cycle of a product, thus becoming an important tool to support decision-making. CDW recycling process produces coarse, fine and mix aggregate as outputs, characterizing a multifunctional process. But, how CDW’s LCA should be run, considering a circular and more sustainable built environment? Thus, the objective of this work is to explore the basic premises in proposing a product system for the CDW recycling process in Brazil. For this, data available in the literature on the recycling process in Brazil and in other countries support the definition of the product system. The complexity of this management option is explored, considering how the use of the recycled materials interfere in the scope, objective, unit function and other modelling choices, as well as reliability of CDW studies. Finally, the datasets provided by Ecoinvent are examined in order to promote debate on data adaptation, followed by remarks on the most appropriate choices on allocation in the CDW LCA. The cut-off system modelling associated with the new perspective on the avoided burden approach is concluded by the authors to be the most suitable for this waste recycling multifunctional processes. Understanding system models is key. When no inventory adaptation is intended, available inventory datasets are more advisable to be used when performing end of life scenarios only, once burdens differ according to countries management scenarios, as well as life cycle inventory approaches

Aplicação da Avaliação do Ciclo de Vida na análise de impactos ambientais de materiais de construção inovadores: estudo de caso da pegada de carbono de clínqueres alternativos

O setor da construção civil é reconhecido como um grande consumidor de recursos, e responsável por diversas emissões que causam impactos substanciais ao ambiente. Muitos destes impactos estão diretamente relacionados à produção de materiais de construção. Por isso, mundialmente cresce a tendência de se propor o uso de materiais de construção inovadores, que considerem a mitigação de seus impactos ambientais no processo produtivo. Para avaliar todos os impactos ambientais relacionados a estes materiais, é necessário que se avalie todas as fases de seu ciclo de vida. Para isso, propõe-se a aplicação da Avaliação do Ciclo de Vida (ACV), metodologia internacionalmente consagrada na avaliação ambiental de produtos, processos e serviços, sendo também normatizada para o cálculo de declarações ambientais de produtos da construção civil. Sabe-se que a produção cimento emite quantidade pronunciadas de gases do efeito estufa. Por isso, neste trabalho, a ACV é aplicada para o cálculo da pegada de carbono de clínqueres alternativos produzidos em laboratório. Os resultados obtidos demonstram uma redução em 22% da pegada de carbono do clínquer alternativo em relação ao clínquer Portland, indicando as etapas do processo produtivo que mais colaboram para estes valores. Ainda, evidencia-se a ampla aplicabilidade da ferramenta ACV ao setor da construção

Optimización multi-objectivo del entorno, forma y envolvente de vivienda social multifamiliar para alcanzar la menor demanda de energía con uso de algoritmo genético

La envolvente de los edificios tiene una gran influencia en su consumo energético. Diseñar arquitectónica y constructivamente la envolvente exterior de un edificio requiere la toma de decisiones de muchas variables, ya sean climáticas, paisajísticas, sociales, ambientales, etc. Los algoritmos genéticos, como en biología, facilitan el cruce de múltiples parámetros a su vez. Este aspecto facilita la maximización o minimización de uno o más objetivos específicos, y así encontrar la solución óptima para los fines especificados. Los algoritmos genéticos, aliados a los softwares de simulación de energía, hacen posible la asociación de muchas variables al mismo tiempo con pocos recursos, contribuyendo en la decisión final del proyecto, que podría ser extremadamente exhaustiva si se hace de forma prescriptiva o una simulación a la vez. En este sentido, este artículo busca establecer qué pautas de diseño de la envolvente de vivienda social multifamiliar en la zona climática 2 de Brasil son las más óptimas, con el análisis integrado de 14 variables constructivas, como el espesor del aislamiento de las paredes y cubierta, el espesor del vidrio, la absortancia térmica de los colores y la proporción de pared y ventana, con el uso del algoritmo genético Non-dominated Sorting Genetic Algorithm (NSGA-II), de acuerdo con los límites descritos en el Código Técnico Español (CTE), y en la NBR 15575, normativa brasileña, haciendo un análisis multi-objetivo para encontrar la mejor relación entre demanda de energía de calefacción y refrigeración.Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles::11.c - Proporcionar suport als països menys avançats, incloent una assistència financera i tècnica, perquè puguin construir edificis sostenibles i resilients utilitzant materials localsObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminan