Environmental life cycle analysis of a water pumping and desalination process powered by intermittent renewable energy sources

International audience

Production and consumption of goods entails generation of obvious and several unseen environmental externalities and burden. Life Cycle Assessment (LCA) essentially includes a detailed analysis of the life cycle of a product or a process in relation to externalities generated [Yuracko and Morris, 2001]. One of the first terms used for such an exercise was Life Cycle Analysis . Recently, two terms viz., Life Cycle Inventory (LCI) and Life Cycle Assessment (LCA) , apart from Life Cycle Inventoiy (LCI) have also been in use. This analysis is aimed at assessing burdens created by the product or process on the environment. LCA normally centres on 1) determination of associated flows of energy and materials; 2) relating environmental impacts and stresses to various stages of production process and consumption of the product; and 3) identification of appropriate interventions to improve environmentally significant attributes. Efforts are currently focused on defining boundaries of analysis and harmonization of approaches for carrying out LCAs [Graedel and Allenby, 1995]. Whichever name is used to describe it, LCA is considered as a useful tool to potentially assist regulators formulate environmental legislation, help manufacturers analyze their processes and improve their products. Like most tools, it must be used with certain clarity of purpose. Life Cycle Analysis and Assessment is being expanded lately to lend support to the development of eco-labelling schemes, which are operating or planned in a number of countries around the world.

Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristics of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statisticalmore » sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue. (See the editorial from this special supplemental issue [Lifset 2012], which introduces this supplemental issue and discusses the origins, funding, peer review, and other aspects.) The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less

Charting the Future of Life Cycle Sustainability Assessment: A Special Issue

Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices.

Much literature is available on fungal lipids and their capability as a renewable oil platform for alternate fuels, chemicals, and food products. Microbial oils will not displace all edible oils soon, given techno-economical hurdles in commercialization. However, continued research & development can flatten the curve of deforestation and land-use impacts associated with cultivating these crops. To better understand how oleaginous yeasts and fungi could alleviate the challenges related to the energy-environment-food nexus, it becomes critical to investigate their potential environmental impacts quantitively compared to other feedstocks. Life cycle analysis or assessment (LCA) is a standard tool used for this purpose. LCA studies are not being conducted on a broader scale for fungus-derived oils than their phototrophic algal counterparts. The different stages in the life cycle of fungal lipid production that can be analyzed for environmental implications include cultivation and fermentation, oil extraction; further downstream processing; and end-use. The LCA method for fungal lipid-derived biofuel production systems should cover the main sustainability concerns of biofuel production systems: energy efficiency, climate change, and land occupation. With the scope of microbial oil applications expanding beyond non-fuel encompassing food, supplements, and medicines, their subsequent environmental implications need to be investigated. Further work is required in this area. There are significant knowledge gaps in life cycle inventory and impact assessment information for non-fuel applications.

Wind Turbines and Adverse Health Effects: A Second Opinion.

In this study, the integration of factors related to life cycle analysis and assessment of building materials and components in the context of widely used methods applied for the evaluation of buildings’ environmental performance is examined. The reviewed assessment systems are BREEAM, LEED, CASBEE, DGNB, HQE and SBTool, with the analysis being focused on their versions referring to new office buildings. Issues related to the content and type of indicators and criteria used for the evaluation of factors referring to life cycle assessment, as well as to the way these rating elements are introduced into the structure and the evaluation process of the aforementioned methods, are examined. In this context, the relative standards and the appropriate –if any– databases and tools mentioned within each method are also demonstrated. The results of this work are systematically presented. The analysis is complemented by the examination of the inclusion of life cycle assessment-related factors in Level(s), a common European framework currently under trial. The present study aims at contributing to the identification of similarities and differences and at highlighting the current trends among widely used buildings’ environmental performance rating systems with regard to the approach they adopt considering building components’ life cycle assessment.

The transition to a low carbon economy provides potential opportunities for Indigenous communities living in remote areas of Australia. Recent studies and trial projects indicate a range of potential benefits from carbon management programs such as early season fire management, bio-sequestration, bioenergy production, and energy monitoring services. Remote Indigenous communities in Australia typically have few employment opportunities, and the health and socio-economic statistics of residents indicate several disadvantages compared to the average non-Indigenous Australian. Despite this many communities maintain a strong culture and a wealth of traditional knowledge, particularly in relation to natural resource management. These carbon management programs offer potential employment and business development prospects that utilise Indigenous knowledge and are in keeping with their caring for country preferences. There is little published information on the carbon profiles of these communities but they are expected to be highly carbon intensive due to their frequent reliance on diesel-powered electricity generators, fossil-fuelled vehicles that need to travel vast distances and housing that often requires energy-intensive thermal conditioning. Hence, efforts are also required to help reduce carbon emissions and associated costs, particularly rising electricity and fuel prices from direct use or those embedded in goods and services. To ascertain whether implementation of proposed carbon management programs can be combined to mitigate carbon emissions a method for estimating and comparing emission abatement across a range of scenarios is required. A carbon accounting model that quantifies the estimated carbon that can be mitigated from sources and sequestered in sinks for a given community has been developed. The model combines two methods of measurement: life cycle analysis and land use modelling techniques. LCA is an assessment of impacts throughout a product's life, or cradle to grave, including raw material acquisition, through production, use and disposal. The AS/NZS ISO standard 14040:1998 Environmental Management- Life cycle assessment - principles and framework outlines the requirements and process for undertaking a life cycle impact assessment. The life cycle analysis is applied in the model to estimate key emission sources for greenhouse gases broadly categorised as follows: materials used for construction and maintenance, construction processes including transport, operating energy supply and demand, transport during the occupancy phase, water systems, and solid waste. Because a full life cycle analysis can be a time and data intensive undertaking only significant items in the community are included and some emissions related to transport and waste are based on annual inventory methods only. Embedded within the life cycle analysis is the model to estimate carbon sinks. The carbon sinks are modelled using a method in accordance with IPCC guidelines for land use, land use change and forestry (LULUCF). This takes into account conversions for a variety of land use categories and, where significant, sub-categories of biomass, dead organic matter and soil. This allows sinks to be estimated within defined limits of uncertainty and a total sequestration quantity to be approximated. The combination of the two measurement methods provides an overall carbon cycle for a community and an estimate of the potential to provide climate change mitigation capacity including a quantitative basis for further economic analysis.

Sustainable Anesthesia

<div class="htmlview paragraph">Life Cycle Analysis (LCA) considers the key environmental impacts for the entire life cycle of alternative products or processes in order to select the best alternative. An ideal LCA would be an expensive and time consuming process because any product or process typically involves many interacting systems and a considerable amount of data must be analysed for each system. Practical LCA methods approximate the results of an ideal analysis by setting limited analysis boundaries and by accepting some uncertainty in the data values for the systems considered. However, there is no consensus in the LCA field on the correct method of selecting boundaries or on the treatment of data set uncertainty. This paper demonstrates a new method of selecting system boundaries for LCA studies and presents a brief discussion on applying Monte Carlo Analysis to treat the uncertainty questions in LCA. These techniques are demonstrated using an LCA which compares ethanol fuel produced from three different biological feedstocks. The methodology applied and the results presented by this work will be of primary interest to LCA practitioners, and the ethanol industry.</div> <div class="htmlview paragraph">Alternative automotive fuels are of significant interest to industries and governments worldwide as concern over the emissions of greenhouse gases rises. Combustion of transportation fuels is the single largest source of greenhouse gas emissions in Canada. Additional concerns of fuel production and use include emissions of ground level ozone precursors and acid forming emissions. Ethanol, used as a fuel additive or as neat fuel, is an alternative to conventional gasoline. However, as this work shows, the numerous feedstocks used in producing ethanol differ greatly with respect to their life cycle environmental performance. The paper compares the environmental effects of producing ethanol in Canada using three potential feedstocks: corn, wheat, and poplar trees. The results show corn ethanol to produce 700 kg CO<sub>2</sub> Equivalents per 1000 liters of ethanol produced, wheat ethanol to result in 760 kg of CO<sub>2</sub> Equiv., and ethanol from poplar trees through a strong acid process to emit 860 kg of CO<sub>2</sub>. The relative importance of production, transportation, processing and combustion is compared for each ethanol feedstock.</div>

Energy, emissions and environmental impact analysis of wind turbine using life cycle assessment technique

PurposeWastewater treatment plants (WWTPs) have long-time environmental impacts. The purpose of this paper is to assess the environmental footprint of two advanced wastewater treatment (WWT) technologies in a life cycle and sustainability perspective and identify the improvement alternatives.Design/methodology/approachIn this study life cycle-based environmental assessment of two advanced WWT technologies (moving bed biofilm reactor (MBBR) and sequencing batch reactor (SBR)) has been carried out to compare different technological options. Life cycle impacts were computed using GaBi software employing the CML 2 (2010) methodology. Primary data were collected and analysed through surveys and on-site visits to WWTPs. The present study attempts to achieve significantly transparent results using life cycle assessment (LCA) in limited availability of data.FindingsThe results of both direct measurements in the studied wastewater systems and the LCA support the fact that advanced treatment has the best environmental performance. The results show that the operation phase contributes to nearly 99 per cent for the impacts of the plant. The study identified emissions associated with electricity production required to operate the WWTPs, chemical usage, emissions to water from treated effluent and heavy metal emissions from waste sludge applied to land are the major contributors for overall environmental impacts. SBR is found to be the best option for WWT as compared to MBBR in the urban context. In order to improve the overall environmental performance, the wastewater recovery, that is, reusable water should be improved. Further, sludge utilisation for energy recovery should be considered. The results of the study show that the avoided impacts of energy recovery can be even greater than direct impacts of greenhouse gas emissions from the wastewater system. Therefore, measures which combine reusing wastewater with energy generation should be preferred. The study highlights the major shortcoming, i.e., the lack of national life cycle inventories and databases in India limiting the wide application of LCA in the context of environmental decision making.Research limitations/implicationsThe results of this study express only the environmental impacts of the operation phase of WWT system and sludge management options. Therefore, it is recommended that further LCAs studies should be carried out to investigate construction and demolition phase and also there is need to reconsider the toxicological- and pathogen-related impact categories. The results obtained through this type of LCA studies can be used in the decision-making framework for selection of appropriate WWT technology by considering LCA results as one of the attributes.Practical implicationsThe results of LCA modelling show that though the environmental impacts associated with advanced technologies are high, these technologies produce the good reusable quality of effluent. In areas where water is scarce, governments should promote reusing wastewater by providing additional treatment under safe conditions as much as possible with advanced WWT. The LCA model for WWT and management planning can be used for the environmental assessment of WWT technologies.Originality/valueThe current work provides a site-specific data on sustainable WWT and management. The study contributes to the development of the regional reference input data for LCA (inventory development) in the domain of wastewater management.

29 - The Life Cycle Assessment of Various Energy Technologies