Combined Life Cycle Assessment Research Articles

BIM na avaliação do ciclo de vida de edificações: revisão da literatura e estudo comparativo

A necessidade da redução do consumo de energia elétrica e de emissão de GHGs (GreenHouse Gases) já é consensual. Sabe-se que edifícios consomem quantidades significativas de energia, além de emitirem grandes quantidades de GHGs. Devido a essa enorme influência sobre a sociedade, é fundamental para arquitetura e construção estar consciente do seu impacto, e desenvolver ferramentas eficazes que são capazes de medir a origem e a possível redução destes impactos, com o uso da avaliação do ciclo de vida de edificações (ACV) aliada ao Building Information Modeling (BIM). Este artigo fornece uma contribuição teórica no campo de integração de BIM e avaliação de ciclo de vida (ACV). A revisão de literatura evidencia que as publicações no tema BIM/ACV concentram-se no desenvolvimento e no melhoramento das ferramentas computacionais para auxiliar a ACV nas fases de projeto e de construção de edificações. São poucas as contribuições que tratam do processo de trabalho. Para contribuir no preenchimento desta lacuna de conhecimento, este artigo analisa o impacto potencial trazido pela adoção de BIM na ACV da perspectiva de processo, tecnologia associada e informação trocada. O método compõe-se de uma revisão sistemática de literatura (RSL), seguida da análise de fluxos de trabalho de avaliação tradicional de energia e emissão de GHGs incorporadas no ciclo de vida comparativamente ao fluxo de trabalho mediado por BIM. A RSL identificou lacunas e tendências de pesquisa, e embasou a elaboração de fluxos de trabalho analisados. Da análise comparativa depreendeu-se que a adoção de BIM no fluxo de trabalho de avaliação de energia incorporada e emissão de GHGs no ciclo de vida de edificações, tem impacto variado no processo de projeto e alto impacto na coleta de dados. A principal vantagem do uso de BIM na ACV é a sua capacidade de otimizar o processo, auxiliar a tomada de decisão durante toda a evolução do projeto e instigar a convergência para uma solução otimizada.

Selecting climate change mitigation strategies in urban areas through life cycle perspectives

Urban governments globally have generated climate change mitigation plans in recent decades. With greenhouse gases (GHG) being emitted from far-ranging anthropogenic sources, selecting mitigation alternatives from a portfolio of options can be highly challenging, particularly when capital budgets and life cycle costs are considered. This research combines life cycle assessment (LCA), life cycle cost accounting (LCCA), and mathematical formulation methods to select ideal alternatives for a case study city. We utilize LCA and LCCA to determine the environmental and economic costs associated with 15 different GHG emission abatement alternatives in four different infrastructure systems: lighting, transportation, buildings, and energy. These abatement alternatives are also assessed for high, medium, and low emission reduction scenarios. For this problem we propose two mathematical formulations to apply to the LCA and LCCA results. The first mathematical formulation is for a single-phase implementation of all selected solution design alternatives; the second mathematical formulation applies to the implementation of alternatives done in three phases. The modeling results reveal the selection differences that occur when capital budgets are varied for both single and multi-phase planning. This unique approach to urban GHG abatement planning can effectively aid policy makers in efficiently selecting best practices in climate change mitigation when balancing environmental and economic perspectives.

Environmental impact trade-offs in building envelope retrofit strategies

Purpose The use of high levels of thermal insulation is a common practice towards reducing the energy consumption of the existing building stock; however, the embodied burdens associated with the additional insulation material are usually not taken into account and questions regarding the risks of over-specifying the insulation levels have been emerging, particularly for mild climate regions. This article addresses the issue presenting an integrated approach that combines life cycle assessment and thermal dynamic simulation to assess alternative retrofit strategies for the roof and exterior walls of two dwellings (from the beginning of the twentieth century), in the historic city center of Coimbra, Portugal. A comprehensive analysis of alternative insulation thicknesses (no insulation, 40, 80, and 120 mm of expanded polystyrene) was made to identify optimal thickness levels minimizing life cycle (LC) environmental impacts for a single-family house and an apartment.

Sustainability assessment and prioritisation of e-waste management options in Brazil

Brazil has an increasing rate of e-waste generation, but there are currently few adequate management systems in operation, with the largest share of Waste Electrical and Electronic Equipment (WEEE) going to landfill sites or entering informal chains. The National Solid Waste Policy (2010) enforces the implementation of reverse logistics systems under the shared responsibility of consumers, companies and governments. The objective of this paper is to assess sustainability and prioritise system alternatives for potential implementation in the metropolitan region of Rio de Janeiro. Sustainability criteria and decision alternatives were defined by elicitation of stakeholders. The adopted multicriteria approach combines Life Cycle Assessment with qualitative evaluations by a small sample of regional experts with knowledge of the problem. The recommended system consists of a hybrid WEEE collection scheme with delivery points at shops, metro stations and neighbourhood centres; a pre-treatment phase with the involvement of private companies, cooperatives and social enterprises; and full recycling of all components in the country.

Dynamic Ecocentric Assessment Combining Emergy and Data Envelopment Analysis: Application to Wind Farms

Most of current life-cycle approaches show an anthropocentric standpoint for the evaluation of human-dominated activities. However, this perspective is insufficient when it comes to assessing the contribution of natural resources to production processes. In this respect, emergy analysis evaluates human-driven systems from a donor-side perspective, accounting for the environmental effort performed to make the resources available. This article presents a novel methodological framework, which combines emergy analysis and dynamic Data Envelopment Analysis (DEA) for the ecocentric assessment of multiple resembling entities over an extended period of time. The use of this approach is shown through a case study of wind energy farms. Furthermore, the results obtained are compared with those of previous studies from two different angles. On the one hand, a comparison with results from anthropocentric approaches (combined life cycle assessment and DEA) is drawn. On the other hand, results from similar ecocentric approaches, but without a dynamic model, are also subject to comparison. The combined use of emergy analysis and dynamic DEA is found to be a valid methodological framework for the computation of resource efficiency and the valuation of ecosystem services. It complements traditional anthropocentric assessments while appropriately including relevant time effects.

Integrating Hybrid Life Cycle Assessment with Multiobjective Optimization: A Modeling Framework.

By combining life cycle assessment (LCA) with multiobjective optimization (MOO), the life cycle optimization (LCO) framework holds the promise not only to evaluate the environmental impacts for a given product but also to compare different alternatives and identify both ecologically and economically better decisions. Despite the recent methodological developments in LCA, most LCO applications are developed upon process-based LCA, which results in system boundary truncation and underestimation of the true impact. In this study, we propose a comprehensive LCO framework that seamlessly integrates MOO with integrated hybrid LCA. It quantifies both direct and indirect environmental impacts and incorporates them into the decision making process in addition to the more traditional economic criteria. The proposed LCO framework is demonstrated through an application on sustainable design of a potential bioethanol supply chain in the UK. Results indicate that the proposed hybrid LCO framework identifies a considerable amount of indirect greenhouse gas emissions (up to 58.4%) that are essentially ignored in process-based LCO. Among the biomass feedstock options considered, using woody biomass for bioethanol production would be the most preferable choice from a climate perspective, while the mixed use of wheat and wheat straw as feedstocks would be the most cost-effective one.

Environmental impacts of genetic improvement of growth rate and feed conversion ratio in fish farming under rearing density and nitrogen output limitations

Today, fish farming faces an increasing demand in fish products, but also various environmental challenges. Genetic improvement in growth rate and feed conversion ratio is known to be an efficient way to increase production and increase efficiency in fish farming. The environmental consequences of genetic improvement in growth rate and feed conversion ratio, however, are unknown. In this study, we investigated the environmental consequences of genetic improvement in growth rate and feed conversion ratio in an African catfish farm, using Recirculating Aquaculture System (RAS). In RAS, total fish production of the farm is limited by rearing density or by the capacity to treat dissolved nitrogen. To evaluate the environmental consequences of genetic improvement in growth rate and feed conversion ratio, we combined life cycle assessment and bioeconomic modelling of genetic response to selection. We explored different impact categories, such as climate change, eutrophication, acidification and energy use, and we expressed impacts per ton of fish produced. Results show that the environmental impact of genetic improvement in growth rate and feed conversion ratio varies among impact categories and depends on the factor limiting production at farm level (i.e. rearing density or nitrogen treatment capacity). Genetic improvement of feed conversion ratio reduces environmental impacts in each scenario tested, while improving growth rate reduces environmental impacts only when rearing density limits farm production. Environmental responses to genetic selection were generally positive and show similar trends as previously determined economic responses to genetic improvement in growth rate and feed conversion ratio in RAS. These results suggest that genetic improvement of growth rate and feed conversion ratio for species kept in RAS will benefit both the environmental impacts and the economics of the production system.

Screening of socio-economic indicators for sustainability assessment: a combined life cycle assessment and data envelopment analysis approach

The combination of life cycle assessment (LCA) and data envelopment analysis (DEA) has recently been proposed to integrate operational, environmental and, to a lesser extent, socio-economic aspects when evaluating multiple similar entities known as decision-making units (DMUs). While labour has already been proven to be an appropriate parameter for implementation in LCA + DEA studies, this article aims to increase the current range of socio-economic indicators suitable for their integration into this novel framework. A sustainability-oriented LCA + DEA method is presented in this article. Furthermore, according to the singular features of the methodological approach, a set of four criteria is defined in order to test the suitability of 40 relevant socio-economic indicators for LCA + DEA implementation. These criteria include quantifiability, DMU specificity, data availability and data quality. Based on the degree of fulfilment of these criteria, the implementability of the indicators is classified as straightforward, likely, unlikely or excluded. According to the proposed criteria, 12 out of 40 socio-economic indicators are found to be suitable, i.e. their implementability in the LCA + DEA framework is considered either straightforward or likely. The difficulty in finding suitable LCA + DEA indicators is found to increase when considering stakeholders with a scope beyond the DMU level. Concerns about the suitability of socio-economic indicators for LCA + DEA as well as potentials and limitations of the approach as a sustainability assessment methodology are discussed. A significant improvement in the socio-economic dimension of LCA + DEA studies for sustainability assessment is achieved. The method proposed is concluded to be a feasible approach for the sustainability assessment of multiple entities, but still with further potentials to be explored.

Hybrid Input‐Output Life Cycle Assessment of First‐ and Second‐Generation Ethanol Production Technologies in Brazil

SummaryA hybrid approach combining life cycle assessment and input‐output analysis was used to demonstrate the economic and environmental benefits of current and future improvements in agricultural and industrial technologies for ethanol production in Brazilian biorefineries. In this article, three main scenarios were evaluated: first‐generation ethanol production with the average current technology; the improved current technology; and the integration of improved first‐ and second‐generation ethanol production. For the improved first‐generation scenario, a US$1 million increase in ethanol demand can give rise to US$2.5 million of total economic activity in the Brazilian economy when direct and indirect purchases of inputs are considered. This value is slightly higher than the economic activity (US$1.8 million) for an energy equivalent amount of gasoline. The integration of first‐ and second‐generation technologies significantly reduces the total greenhouse gas emissions of ethanol production: 14.6 versus 86.4 grams of carbon dioxide equivalent per megajoule (g CO2‐eq/MJ) for gasoline. Moreover, emissions of ethanol can be negative (–10.5 g CO2‐eq/MJ) when the system boundary is expanded to account for surplus bioelectricity by displacement of natural gas thermal electricity generation considering electricity produced in first‐generation optimized biorefineries.

Cost combined life cycle assessment of lignite-based electricity generation

Life cycle assessment and life cycle costing were carried out to identify the environmental and economic burdens of six lignite-based electricity generation scenarios. Coal-based electricity generation is used as control. Results showed that diesel consumption for road transport, energy (i.e., electricity and steam) consumption for lignite drying, and the use of coal/lignite had dominant contributions to overall environmental and economic burden. Direct heavy metal and dibenz(a,h)anthracene emissions form electricity generation represented an additional important role to the total environmental effect for all scenarios. Lignite drying with steam drum and steam fluid bed scenarios present higher economic benefits than the coal-based scenario, whereas their environmental burden is higher than that of the coal-based scenario. Results indicate that lignite drying with microwave, tube type, and rotary drum technologies are unsuitable for lignite utilization in terms of cost and environmental views.

Application of Life Cycle Assessment (LCA) and Design of Experiments (DOE) to the Monitoring and Control of a Grinding Process

The number of studies on green manufacturing has increased over the past years and particular focus has been placed on machining processes and the application of Life Cycle Assessment (LCA). This paper reports the results of the use of a modeling approach that combines Life Cycle Assessment (LCA) and Design of Experiments (DOE) to investigate a cylindrical plunge grinding for 21-2N steel. The effect of two process parameters on the LCA results of the grinding machining was studied through an analysis of variance (ANOVA). The parameters investigated were type of CBN grinding wheel (JB126 K150 VSS and 8B126 K150 VT2) and different levels of specific material removal rate (50, 100, 150 and 200mm3/mm.min).

Combined MFA and LCA approach to evaluate the metabolism of service polygons: A case study on a university campus

Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) are widely employed in the study of topics related to industrial ecology. However, unlike this study, they are normally used separately rather than jointly. Educational institutions are among the most deeply rooted services in society, producing knowledge, research and culture. This paper reports on a case study conducted in the region of Catalonia, Spain, to evaluate the metabolism of the Autonomous University of Barcelona (UAB) based on a combined MFA and LCA approach on two levels: macro-level analysis using MFA, and micro-level analysis using LCA. The MFA results indicated that energy consumption represents more than 50.00% of all inputs, and its associated indirect flows are highly relevant for UAB's overall metabolism, accounting for 69.30% of all energy inputs. As for the LCA results, the ReCiPe2008 method was adopted and 92.00% of all normalized impacts were related to the category of Climate Change Potential (CCP), also attributed mainly to energy consumption. Thus, both MFA and LCA methodologies indicated energy consumption is the main hotspot. The results of MFA indicators, energy and water flows were compared with earlier literature, revealing a clear tendency for industrial areas in Catalonia to show higher results than service polygons, as an effect of population density. Finally, the newly erected building of the Institute of Environmental Science and Technology and the Catalan Institute of Paleontology (ICTA-ICP) is described as an innovative alternative to promote environmental sustainability at universities that focus on energy and water conservation and CCP impacts reduction.

Impact of progressive sustainable target value assessment on building design decisions

The built environment creates significant environmental, economic, and social impacts. In the building construction industry, building designers, contractors, and owners have developed methods to consider costs, but currently have few methods to effectively assess and control a building's life cycle energy and environmental impacts during the design phase. Managing and reducing these environmental impacts during the course of design development requires iterative assessment and rapid information turnaround and decision-making. When left unconsidered, poor environmental design decisions leave potential design revisions and their value unrealized. This research combines life cycle assessment (LCA) and target value design (TVD) to rapidly produce more sustainable building designs in a methodology called sustainable target value (STV) design. The STV design process involves environmental design targets and an STV tool to quantify environmental design performance in an iterative design process. By establishing site-specific sustainability targets and iteratively using the STV tool to assess the impacts of design changes, this research demonstrates that building designs can be improved at the design stage to perform at higher environmental standards than if they are only assessed once design is complete.

Eco-efficiency analysis of Spanish WWTPs using the LCA + DEA method

Wastewater treatment plants (WWTPs) are regarded as units designed for the efficient removal of organic matter and nutrients from polluted wastewaters, avoiding their discharge into the environment. Despite these benefits, they have also been found to be highly energy intensive, with consequent increased emissions in terms of greenhouse gases and other environmental impacts. Therefore, it has become imperative to monitor thoroughly the overall functioning of WWTPs from an integrated perspective with the aim of understanding how these can improve their eco-efficiency. In this case study, a group of 113 WWTPs located in regions across Spain were analysed using the methodology that combines life cycle assessment (LCA) and data envelopment analysis (DEA). The aim of this work was to determine the operational efficiency of each unit in order to obtain environmental benchmarks for inefficient plants. Thereafter, the environmental gains linked with the inputs reduction proposed for the DEA model for each unit were computed in order to verify eco-efficiency criteria. The operational complexity of WWTPs resulted in several identified factors affecting their efficiency which are discussed in depth, including the size of the facility, the climatic influence, the influent load and the over- or underuse of the plant.

Combining Life Cycle Assessment with Data Science to Inform Portfolio‐Level Value‐Chain Engineering

SummaryLife cycle assessment (LCA)‐based analyses of company value chains can inspire profound modifications to products’ design, material procurement, manufacturing, energy/water use, distribution, use, and disposal. However, such modifications often create trade‐offs, improving some aspects while worsening others. How can firms decide whether or not to carry out such modifications? Or prioritize between different options to choose the one delivering the most competitive advantage? Typically, firms’ metrics fall into two groups: (1) product‐level metrics across the life cycle, including up‐ and downstream of facilities (e.g., product carbon footprints); and (2) facility‐level metrics (e.g., plants’ annual energy cost). Neither is sufficient for firm‐wide cost‐benefit analyses of modifications that affect multiple products and value‐chain stages. Whereas facility‐level metrics do not capture up‐ and downstream effects—where often most cost and environmental impacts originate—life cycle methodologies are currently not mature enough to be applied at the scale of entire product portfolios. We present a pilot system of key performance indicators (KPIs) that evaluate 3,337 products across 211 brands and five countries of PepsiCo, Inc. KPIs are firm‐wide, annual figures (environmental, operational, and financial) across the value chain (cradle to grave) and can be determined at any level (single product, brands, or regions). Uncertainty analysis is included. In addition to KPIs for base cases, the system characterizes KPI impacts for any considered modifications (what‐if scenarios). In a detailed case study, we present background about how and why PepsiCo used the system to evaluate all aspects of a strategic value‐chain modification. For 7 of the 211 brands, this resulted in avoiding an 8% increase in greenhouse gas emissions and a 7% to 10% increase in procurement costs. It also saved PepsiCo an estimated ∼200 years full‐time equivalent employee time (or alternatively ∼US$30 million in LCA consultant fees) had the LCAs of the 3,337 SKUs been carried out by traditional methods. This cost efficiency of the KPI system enables considering environmental impacts with more‐traditional business metrics side by side. As a result, environmental impacts can be considered on a routine basis as part of integrated strategy and business planning. We discuss implementation considerations of the KPI methodology and future improvements.

Combining life cycle assessment and qualitative risk assessment: The case study of alumina nanofluid production

In this paper the authors propose a framework for combining life cycle assessment (LCA) and Risk Assessment (RA) to support the sustainability assessment of emerging technologies. This proposal includes four steps of analysis: technological system definition; data collection; risk evaluation and impacts quantification; results interpretation. This scheme has been applied to a case study of nanofluid alumina production in two different pilot lines, “single-stage” and “two-stage”. The study has been developed in the NanoHex project (enhanced nano-fluid heat exchange). Goals of the study were analyzing the hotspots and highlighting possible trade-off between the results of LCA, which identifies the processes having the best environmental performance, and the results of RA, which identifies the scenarios having the highest risk for workers. Indeed, due to lack of data about exposure limits, exposure–dose relationships and toxicity of alumina nanopowders (NPs) and nanofluids (NF), the workplace exposure has been evaluated by means of qualitative risk assessment, using Stoffenmanager Nano. Though having different aims, LCA and RA have a complementary role in the description of impacts of products/substances/technologies. Their combined use can overcome limits of each of them and allows a wider vision of the problems to better support the decision making process.

Economic and environmental sustainability of forestry measures in Apulia Region Rural Development Plan: An application of life cycle approach

This article investigates the applicability of combined Life Cycle Assessment and market analysis, to support efficiency evaluation of rural development strategies developed by the Apulian Rural Development Plan 2007–2013 (BURP n 93 26/05/2010). Measure 122 “Improving the economic value of forest” had the aim to improve of forestry farms technological resources addressing them toward the biomass production. As an example pellet production from sawmill residues (PSR) and firewood productions have been compared both under environmental and economic performances. The functional unit (FU) is 1kWh of residential thermal energy. Environmental impacts of both fuels have been evaluated through the Life Cycle Assessment methodology, considering the most relevant impact categories: the damages on human health, the ecosystems qualities, the kg of CO2eq. produced (GWP100) and the balance between energy requests and consumed (Cumulative Energy Demand – CED). About the economic analysis, data on pellet and firewood local market prices have been collected and consumer's expenditure for FU calculated. Results supplied relevant suggestions to improve efficiency and farmer's subscription to Apulia Regional Development Plan forestry measures.

Using systems-based life cycle assessment to investigate the environmental and economic impacts and benefits of the livestock sector in the UK

The livestock industry is a significant component of the agricultural and rural sectors in the UK. Grassland for livestock accounts for almost half of the terrestrial surface of the UK and almost two-thirds of its managed agricultural land. It therefore accounts for a major proportion of rural employment and income and provides many landscape and biodiversity benefits. Taking an ecosystems-services-framework approach, an integrated livestock-ecosystems linear programming model was developed to assess economic and environmental impacts of the livestock sector. This combined life cycle assessment systems analysis with economic and valuation data and enabled plausible future scenarios to be assessed in terms of provisioning, regulating and cultural services. Analysis showed the main benefit coming from provisioning services and also the significant role the sector plays in providing cultural services, and the trade-offs between these and the cost of regulating services with respect to emissions to air and water.

Joint Life Cycle Assessment and Data Envelopment Analysis for the benchmarking of environmental impacts in rice paddy production

The combined implementation of Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) has been identified as a suitable tool for the evaluation of the environmental and economic performance of multiple similar entities. In this study, a total of 82 rice paddy fields for spring and summer growing seasons in north of Iran were assessed using a combined LCA and DEA methodology to estimate the technical efficiency of each farmer. Furthermore, the environmental consequences of operational inefficiencies were quantified and target performance values benchmarked for inefficient units so that eco-efficiency criteria were verified. Results showed average reduction levels of up to 20% and 25% per material input for spring and summer systems, leading to impact reductions which ranged from 8% to 11% for spring farms and 19% to 25% for summer farms depending on the chosen impact category. Additionally, the potential economic savings from efficient farming operations were also determined. The economic results indicate that an added annual gross margin of 0.045 $ per 1 kg rice paddy could be achieved if inefficient units converted to an efficient operation.

Using LCA‐based Decomposition Analysis to Study the Multidimensional Contribution of Technological Innovation to Environmental Pressures

SummaryThis article presents a general framework for macroenvironmental assessment, combining life cycle assessment (LCA) with the IPAT equation, and explores its combination with decomposition analysis to assess the multidimensional contribution of technological innovation to environmental pressures. This approach is illustrated with a case study in which carbon dioxide (CO2) and nitrogen oxides (NOx) air emissions from diesel passenger cars in Europe during the period 1990–2005 are first decomposed using index decomposition analysis into technology, consumption activity, and population growth effects. By a second decomposition, the contribution of a specific innovation (diesel engine) is calculated on the basis of the technology and consumption activity effects, through a technological comparison with a relevant alternative and the calculation of the rebound effect, respectively. The empirical analysis for diesel passenger cars highlights the discrepancies between the micro (LCA) and macro (IPAT‐LCA) analytical approaches. Thus, whereas diesel engines present a relatively less‐pollutant environmental product profile than their gasoline counterparts, total CO2 and NOx emissions would have increased partly as a consequence of their introduction, mainly driven by the increase in travel demand caused by the induced direct price rebound effect from fuel savings and fuel price differences. The counterintuitive result shows the need for such an analysis.