A life cycle comparison of disposal and beneficial use of coal combustion products in Florida

Background, Goal, and Scope

Currently, only 40%, or 44.5 million metric tons, of coal combustion products (CCPs) generated in the United States each year by electric utilities are diverted from disposal in landfills or surface impoundments and recycled. Despite promising economic and environmental savings, there has been scant attention devoted to assessing life cycle impacts of CCP disposal and beneficial use. The objective of this paper is to present a life cycle inventory considering two cases of CCP management, including the stages of coal mining and preparation, coal combustion, CCP disposal, and CCP beneficial use. Six beneficial uses were considered: concrete production, structural fills, soil amendments, road construction, blasting grit and roofing granules, and wallboard.

Methods

Primary data for raw material inputs and emissions of all stages considered were obtained from surveys and site visits of coal-burning utilities in Florida conducted in 2002, and secondary data were obtained from various published sources and from databases available in SimaPro 5.1 (PRé Consultants, Amersfoort, The Netherlands).

Results

Results revealed that 50 percent of all CCPs produced, or 108 kg per 1,000 kg of coal combusted, are diverted for application in a beneficial use; however, the relative amounts sold by each utility is dependent on the process operating parameters, air emission control devices, and resulting quality of CCP. Diversion of 50% of all CCPs to beneficial use applications yields a decrease in the total raw materials requirements (with the exception of gravel and iron) and most emissions to air, water, and land, as compared to 100% disposal.

Discussion

The greatest reduction of raw materials was attributed to replacing Portland cement with fly ash, using bottom ash as an aggregate in concrete production and road construction in place of natural materials, and substituting FGD gypsum for natural gypsum in wallboard. The use of fly ash as cementitious material in concrete also promised significant reductions in emissions, particularly the carbon dioxide that would be generated from Portland cement production. Beneficial uses of fly ash and gypsum showed reductions of emissions to water (particularly total dissolved solids) and emissions of metals to land, although these reductions were small compared to simply diverting 50% of all CCPs from landfills or surface impoundments.

Conclusions

This life cycle inventory (LCI) provides the foundation for assessing the impacts of CCP disposal and beneficial use. Beneficial use of CCPs is shown here to yield reductions in raw material requirements and various emissions to all environmental compartments, with potential tangible savings to human health and the environment.

Recommendations and Perspectives

Extension of this life cycle inventory to include impact assessment and sensitivity analysis will enable a determination of whether the savings in emissions reported here actually result in significant improvements in environmental and human health impacts.

     

A review of indicators of climate change for use in Ireland

Impact indicators are systems/organisms, the vitality of which alters in response to changes in environmental condition. The indicators assessed in this review fall within the impact category of the driver-pressure-state-impact-response (DPSIR) framework. Instrumental records have shown unequivocal changes in climatic conditions over the past 30 years at a global level but impact indicators allow these changes to be monitored at a finer resolution. Our main aim was to review sets of indicators of climate change currently used in various countries and to make recommendations for their use in the Irish environment. We review a preliminary set of climate change impact indicators in five sectors: agriculture; plant and animal distribution patterns; phenology; palaeoecology and human health. Currently, the most effective impact indicators of climate change have proved to be phenological observations of tree developmental stages. The strongest factor limiting the use of indicators is the lack of long-term data sets from which a climatic signal can be extracted.     

A simple methodology for elaborating the life cycle inventory of agricultural products

Goal, Scope and Background  A methodological approach for representing agricultural products in terms of life cycle inventory is suggested in this paper. This approach was developed during the conduction of an LCA study for two perennial crops of important Brazilian exportation products: green coffee and orange juice, which included tillage cultivation by commercial farms, harvest, as well as product processing when pertinent. The published papers on agricultural products LCA usually discuss the final results in terms of LCIA, being not very clear what methodology or principles were applied on the LCI phase. The aim of this paper is to present a simple methodology that would be employed by different stakeholders as farmers, environment managers and decision makers for evaluating the environmental performance of their products. In recent years, many researchers have tried to make a worldwide effort in order to reach comparable results of LCA studies developed in different countries. So, the proposed methodology has also the aim of isolating the site-dependency of the results that are not strictly related to the agricultural production. The time coverage suggested is the period can be considered as an average for the specific tillage under evaluation, usually two crops, since there is a large variation on the inputs in every other crop, including the higher and subsequent lower productive periods. Method  The functional unit recommended is 1,000 kg of the specific product, being recommended to distinguish the energy used for the cultivation from that used by the processing stage. There are several specific considerations to transform the data collected through the questionnaires in an inventory data set of fertilizers (macro and micro nutrients), correctives, fillers and pesticides further detailed. Water used for chemicals preparation, in the cleaning and processing stages of the harvested crop is also considered. Land use refers to the area used land for cultivation divided by the medium life period of the tillage. The stoichiometric balance is performed based on the elementary composition of the products. An average carbohydrate formula is established for the products considering the relationship among the carbon, hydrogen and oxygen contents of them. The carbohydrate formula (output) is balanced with carbon dioxide and water (inputs) according to the basic principles of the photosynthesis reaction. The differences among the mineral composition of the products and the total content of these elements (N, P, K, Ca, Mg and micronutrients elements) for all the crop inputs (fertilizers, pesticides, correctives) are allocated as outputs of the system. The pesticides is counted in two forms: grouped in classes (herbicide, fungicide, acaricide, bactericide and inseticide) and specified by the chemical name of the active ingredient. Results and Discussion  A simplified inventory useful for different purposes is generated with the principles described in this paper. The exact fate of each pesticide, fertilizer or corrective or assumptions can be further associated to impact categories as nutriphication, human health, natural resources depletion, ecological toxicity, etc. In this approach the mass balance was focused in the grain or fruit growth and not in the plant or tree as a whole, considering basically the elementary composition of the product and the photosynthesis principle. Despite agricultural LCAs performed in different countries have been published, neither of them considers the carbon capture by the agricultural products during their growth. Conclusions  This method is based on well accepted universal principles of stoichiometry applied to the grain or fruit growth. Minimum estimations were introduced in this approach, which produces ‘clean inventories’, with comparable results between different studies. The generated inventory can be gradually improved as the understanding about each emission fate is known, producing a valid methodology for actual and future knowledge about the fate of tillage emissions. The inventory results of this method can be employed by different stakeholders as farmers, environment managers, decision makers and traders, with valuable environmental parameters for evaluating the environmental performance of their products and also for introducing improvements on their systems, without however to exhibit any particular data.     

Life cycle assessment of Australian automotive door skins

Background, aim, and scope  Policy initiatives, such as the EU End of Life Vehicle (ELV) Directive for only 5% landfilling by 2015, are increasing the pressure for higher material recyclability rates. This is stimulating research into material alternatives and end-of-life strategies for automotive components. This study presents a Life Cycle Assessment (LCA) on an Australian automotive component, namely an exterior door skin. The functional unit for this study is one door skin set (4 exterior skins). The material alternatives are steel, which is currently used by Australian manufacturers, aluminium and glass-fiber reinforced polypropylene composite. Only the inputs and outputs relative to the door skin production, use and end-of-life phases were considered within the system boundary. Landfill, energy recovery and mechanical recycling were the end-of-life phases considered. The aim of the study is to highlight the most environmentally attractive material and end-of-life option. Methods  The LCA was performed according to the ISO 14040 standard series. All information considered in this study (use of fossil and non fossil based energy resources, water, chemicals etc.) were taken up in in-depth data. The data for the production, use and end-of-life phases of the door skin set was based upon softwares such as SimaPro and GEMIS which helped in the development of the inventory for the different end-of-life scenarios. In other cases, the inventory was developed using derivations obtained from published journals. Some data was obtained from GM-Holden and the Co-operative research Centre for Advanced Automotive Technology (AutoCRC), in Australia. In cases where data from the Australian economy was unavailable, such as the data relating to energy recovery methods, a generic data set based on European recycling companies was employed. The characterization factors used for normalization of data were taken from (Saling et. al. Int J Life Cycle Assess 7(4):203–218 2002) which detailed the method of carrying out an LCA. Results  The production phase results in maximum raw material consumption for all materials, and it is higher for metals than for the composite. Energy consumption is greatest in the use phase, with maximum consumption for steel. Aluminium consumes most energy in the production phase. Global Warming Potential (GWP) also follows a trend similar to that of energy consumption. Photo Oxidants Creation Potential (POCP) is the highest for the landfill scenario for the composite, followed by steel and aluminium. Acidification Potential (AP) is the highest for all the end-of-life scenarios of the composite. Ozone Depletion Potential (ODP) is the highest for the metals. The net water emissions are also higher for composite in comparison to metals despite high pollution in the production phases of metallic door skins. Solid wastes are higher for the metallic door skins. Discussion  The composite door skin has the lowest energy consumption in the production phase, due to the low energy requirements during the manufacturing of E-glass and its fusion with polypropylene to form sheet molding compounds. In general, the air emissions during the use phase are strongly dependent on the mass of the skins, with higher emissions for the metals than for the composite. Material recovery through recycling is the highest in metals due to efficient separation techniques, while mechanical recycling is the most efficient for the composite. The heavy steel skins produce the maximum solid wastes primarily due to higher fuel consumption. Water pollution reduction benefit is highest in case of metals, again due to the high efficiency of magnetic separation technique in the case of steel and eddy current separation technique in the case of aluminium. Material recovery in these metals reduces the amount of water needed to produce a new door skin set (water employed mainly in the ingot casting stage). Moreover, the use of heavy metals, inorganic salts and other chemicals is minimized by efficient material recovery. Conclusions  The use of the studied type of steel for the door skins is a poor environmental option in every impact category. Aluminium and composite materials should be considered to develop a more sustainable and energy efficient automobile. In particular, this LCA study shows that glass-fiber composite skins with mechanical recycling or energy recovery method could be environmentally desirable, compared to aluminium and steel skins. However, the current limit on the efficiency of recycling is the prime barrier to increasing the sustainability of composite skins. Recommendations and perspectives  The study is successful in developing a detailed LCA for the three different types of door skin materials and their respective recycling or end-of-life scenarios. The results obtained could be used for future work on an eco-efficiency portfolio for the entire car. However, there is a need for a detailed assessment of toxicity and risk potentials arising from each of the four different types of door skin sets. This will require greater communication between academia and the automotive industry to improve the quality of the LCA data. Sensitivity analysis needs to be performed such as the assessment of the impact of varying substitution factors on the life cycle of a door skin. Incorporation of door skin sets made of new biomaterials need to be accounted for as another functional unit in future LCA studies. Discussion contributions to this article from the readership would the highly welcome. The authors     

Using monte carlo simulation in life cycle assessment for electric and internal combustion vehicles

1 Background

The U.S. Government has encouraged shifting from internal combustion engine vehicles (ICEVs) to alternatively fueled vehicles such as electric vehicles (EVs) for three primary reasons: reducing oil dependence, reducing greenhouse gas emissions, and reducing Clean Air Act criteria pollutant emissions. In comparing these vehicles, there is uncertainty and variability in emission factors and performance variables, which cause wide variation in reported outputs.

2 Objectives

A model was developed to demonstrate the use of Monte Carlo simulation to predict life cycle emissions and energy consumption differences between the ICEV versus the EV on a per kilometer (km) traveled basis. Three EV technologies are considered: lead-acid, nickel-cadmium, and nickel metal hydride batteries.

3 Methods

Variables were identified to build life cycle inventories between the EVs and ICEV. Distributions were selected for each of the variables and input to Monte Carlo Simulation soft-ware called Crystal Ball 2000®.

4 Results and Discussion

All three EV options reduce U.S. oil dependence by shifting to domestic coal. The life cycle energy consumption per kilometer (km) driven for the EVs is comparable to the ICEV; however, there is wide variation in predicted energy values. The model predicts that all three EV technologies will likely increase oxides of sulfur and nitrogen as well as particulate matter emissions on a per km driven basis. The model shows a high probability that volatile organic compounds and carbon monoxide emissions are reduced with the use of EVs. Lead emissions are also predicted to increase for lead-acid battery EVs. The EV will not reduce greenhouse gas emissions substantially and may even increase them based on the current U.S. reliance on coal for electricity generation. The EV may benefit public health by relocating air pollutants from urban centers, where traffic is concentrated, to rural areas where electricity generation and mining generally occur. The use of Monte Carlo simulation in life cycle analysis is demonstrated to be an effective tool to provide further insight on the likelihood of emission outputs and energy consumption.     

Land use and biodiversity indicators for life cycle impact assessment

Background  The primary purpose of environmental assessment is to protect biological systems. Data collected over the last several decades indicates that the greatest impacts on biological resources derive from physical changes in land use. However, to date there is no consensus on indicators of land use that could be applicable worldwide at all scales. This has hampered the assessment of land use in the context of LCA. Objectives  The Institute for Environmental Research and Education and its partner Defenders of Wildlife have begun an effort to develop the necessary consensus. Methods  In July 2000, they held a workshop attended by a diverse group of interested parties and experts to develop a preliminary list of life cycle indicators for land use impacts. Results  Their preliminary list of impact indicators includes: protection of priority habitats/species; soil characteristics: soil health; proximity to & protection of high priority vegetative communities; interface between water and terrestrial habitats/buffer zones; assimilative capacity of water and land; hydrological function; percent coverage of invasive species within protected areas; road density; percent native-dominated vegetation; restoration of native vegetation; adoption of Best Management Practices linked to biodiversity objectives; distribution (patchiness; evenness, etc.); and connectivity of native habitat. Conclusion  The list of indicators conforms well to other efforts in developing indicators. There appears to be convergence among experts in the field and in related fields on the appropriate things to measure. Future Prospects  These indicators are currently being tested in the United States. Further workshops and testing is planned towards developing internationally recognized indicators for land use.     

A survey of unresolved problems in life cycle assessment

Background, aims, and scope  Life cycle assessment (LCA) stands as the pre-eminent tool for estimating environmental effects caused by products and processes from ‘cradle to grave’ or ‘cradle to cradle.’ It exists in multiple forms, claims a growing list of practitioners, and remains a focus of continuing research. Despite its popularity and codification by organizations such as the International Organization for Standards and the Society of Environmental Toxicology and Chemistry, life cycle assessment is a tool in need of improvement. Multiple authors have written about its individual problems, but a unified treatment of the subject is lacking. The following literature survey gathers and explains issues, problems and problematic decisions currently limiting LCA’s goal and scope definition and life cycle inventory phases. Main features  The review identifies 15 major problem areas and organizes them by the LCA phases in which each appears. This part of the review focuses on the first 7 of these problems occurring during the goal and scope definition and life cycle inventory phases. It is meant as a concise summary for practitioners interested in methodological limitations which might degrade the accuracy of their assessments. For new researchers, it provides an overview of pertinent problem areas toward which they might wish to direct their research efforts. Results and discussion  Multiple problems occur in each of LCA’s four phases and reduce the accuracy of this tool. Considering problem severity and the adequacy of current solutions, six of the 15 discussed problems are of paramount importance. In LCA’s first two phases, functional unit definition, boundary selection, and allocation are critical problems requiring particular attention. Conclusions and recommendations  Problems encountered during goal and scope definition arise from decisions about inclusion and exclusion while those in inventory analysis involve flows and transformations. Foundational decisions about the basis of comparison (functional unit), bounds of the study, and physical relationships between included processes largely dictate the representativeness and, therefore, the value of an LCA. It is for this reason that problems in functional unit definition, boundary selection, and allocation are the most critical examined in the first part of this review.

A Carbon Footprint of Textile Recycling: A Case Study in Sweden

Global population growth and rising living standards are increasing apparel consumption. Consequently, consumption of resources and generation of textile waste are increasing. According to the Swedish Environmental Protection Agency, textile consumption increased by 40% between the years 2000 and 2009 in Sweden. Given that there is currently no textile recycling plant in Sweden, the aim of this article is to explore the potential environmental benefits of various textile recycling techniques and thereby direct textile waste management strategies toward more sustainable options. Three different recycling techniques for a model waste consisting of 50% cotton and 50% polyester were identified and a life cycle assessment (LCA) was made to assess the environmental performance of them. The recycling processes are: material reuse of textile waste of adequate quality; separation of cellulose from polyester using N‐methylmorpholine‐N‐oxide as a solvent; and chemical recycling of polyester. These are compared to incineration, representing conventional textile waste treatment in Sweden. The results show that incineration has the highest global warming potential and primary energy usage. The material reuse process exhibits the best performance of the studied systems, with savings of 8 tonnes of carbon dioxide equivalents (CO₂‐eq) and 164 gigajoules (GJ) of primary energy per tonne of textile waste. Sensitivity analyses showed that results are particularly sensitive to the considered yields of the processes and to the choice of replaced products. An integration of these recycling technologies for optimal usage of their different features for treatment of 1 tonne of textile waste shows that 10 tonnes CO₂‐eq and 169 GJ of primary energy could be saved.     

A review of methods for characterizing the environmental consequences of actions in life cycle assessment

Understanding the environmental consequences of actions is becoming increasingly important in the field of industrial ecology in general, and in life cycle assessment (LCA) more specifically. However, a consensus on how to operationalize this idea has not been reached. A variety of methods have been proposed and applied to case studies that cover various aspects of consequential life cycle assessment (CLCA). Previous reviews of the topic have focused on the broad agenda of CLCA and how different modeling frameworks fit into its goals. However, explicit examination of the spectrum of methods and their application to the different facets of CLCA are lacking. Here, we provide a detailed review of methods that have been used to construct models of the environmental consequences of actions in CLCA. First, we cover the following structural modeling approaches: (a) economic equilibrium models, (b) system dynamics models, (c) technology choice models, and (d) agent‐based models. We provide a detailed review of particular applications of each model in the CLCA domain. The advantages and disadvantages of each are discussed, and their relationships with CLCA are clarified. From this, we are able to map these models onto the established aspects of CLCA. We learn that structural models alone are not sufficient to quantify the uncertainty distributions of underlying parameters in CLCA, which are essential components of a robust analysis of consequences. To address this, we provide a brief introduction to a counterfactual‐based causal inference approach to parameter identification and uncertainty analysis that is emerging in the CLCA literature. We recommend that one potential research path forward is the establishment of feedback loops between empirical estimates and structural models.     

Integration of life cycle assessment in the environmental information system

Background, aim, and scope  As the sustainability improvement becomes an essential business task of industry, a number of companies are adopting IT-based environmental information systems (EIS). Life cycle assessment (LCA), a tool to improve environmental friendliness of a product, can also be systemized as a part of the EIS. This paper presents a case of an environmental information system which is integrated with online LCA tool to produce sets of hybrid life cycle inventory and examine its usefulness in the field application of the environmental management. Main features  Samsung SDI Ltd., the producer of display panels, has launched an EIS called Sustainability Management Initiative System (SMIS). The system comprised modules of functions such as environmental management system (EMS), green procurement (GP), customer relation (e-VOC), eco-design, and LCA. The LCA module adopted the hybrid LCA methodology in the sense that it combines process LCA for the site processes and input–output (IO) LCA for upstream processes to produce cradle-to-gate LCA results. LCA results from the module are compared with results of other LCA studies made by the application of different methodologies. The advantages and application of the LCA system are also discussed in light of the electronics industry. Results and discussion  LCA can play a vital role in sustainability management by finding environmental burden of products in their life cycle. It is especially true in the case of the electronics industry, since the electronic products have some critical public concerns in the use and end-of-life phase. SMIS shows a method for hybrid LCA through online data communication with EMS and GP module. The integration of IT-based hybrid LCA in environmental information system was set to begin in January 2006. The advantage of the comparing and regular monitoring of the LCA value is that it improves the system completeness and increases the reliability of LCA. By comparing the hybrid LCA and process LCA in the cradle-to-gate stage, the gap between both methods of the 42-in. standard definition plasma display panel (PDP) ranges from 1% (acidification impact category) to −282% (abiotic resource depletion impact category), with an average gap of 68.63%. The gaps of the impact categories of acidification (AP), eutrophication (EP), and global warming (GWP) are relatively low (less than 10%). In the result of the comparative analysis, the strength of correlation of three impact categories (AP, EP, GWP) shows that it is reliable to use the hybrid LCA when assessing the environmental impacts of the PDP module. Hybrid LCA has its own risk on data accuracy. However, the risk is affordable when it comes to the comparative LCA among different models of similar product line of a company. In the results of 2 years of monitoring of 42-in. Standard definition PDP, the hybrid LCA score has been decreased by 30%. The system also efficiently shortens man-days for LCA study per product. This fact can facilitate the eco-design of the products and can give quick response to the customer's inquiry on the product's eco-profile. Even though there is the necessity for improvement of process data currently available, the hybrid LCA provides insight into the assessments of the eco-efficiency of the manufacturing process and the environmental impacts of a product. Conclusions and recommendations  As the environmental concerns of the industries increase, the need for environmental data management also increases. LCA shall be a core part of the environmental information system by which the environmental performances of products can be controlled. Hybrid type of LCA is effective in controlling the usual eco-profile of the products in a company. For an industry, in particular electronics, which imports a broad band of raw material and parts, hybrid LCA is more practicable than the classic LCA. Continuous efforts are needed to align input data and keep conformity, which reduces data uncertainty of the system.     

Allocation of energy use in petroleum refineries to petroleum products

Aim, Scope, and Background  Studies to evaluate the energy and emission impacts of vehicle/fuel systems have to address allocation of the energy use and emissions associated with petroleum refineries to various petroleum products because refineries produce multiple products. The allocation is needed in evaluating energy and emission effects of individual transportation fuels. Allocation methods used so far for petroleum-based fuels (e.g., gasoline, diesel, and liquefied petroleum gas [LPG]) are based primarily on mass, energy content, or market value shares of individual fuels from a given refinery. The aggregate approach at the refinery level is unable to account for the energy use and emission differences associated with producing individual fuels at the next sub-level: individual refining processes within a refinery. The approach ignores the fact that different refinery products go through different processes within a refinery. Allocation at the subprocess level (i.e., the refining process level) instead of at the aggregate process level (i.e., the refinery level) is advocated by the International Standard Organization. In this study, we seek a means of allocating total refinery energy use among various refinery products at the level of individual refinery processes. Main Features  We present a petroleum refinery-process-based approach to allocating energy use in a petroleum refinery to petroleum refinery products according to mass, energy content, and market value share of final and intermediate petroleum products as they flow through refining processes within a refinery. The approach is based on energy and mass balance among refining processes within a petroleum refinery. By using published energy and mass balance data for a simplified U.S. refinery, we developed a methodology and used it to allocate total energy use within a refinery to various petroleum products. The approach accounts for energy use during individual refining processes by tracking product stream mass and energy use within a refinery. The energy use associated with an individual refining process is then distributed to product streams by using the mass, energy content, or market value share of each product stream as the weighting factors. Results  The results from this study reveal that product-specific energy use based on the refinery process-level allocation differs considerably from that based on the refinery-level allocation. We calculated well-to-pump total energy use and greenhouse gas (GHG) emissions for gasoline, diesel, LPG, and naphtha with the refinery process-based allocation approach. For gasoline, the efficiency estimated from the refinery-level allocation underestimates gasoline energy use, relative to the process-level based gasoline efficiency. For diesel fuel, the well-to-pump energy use for the process-level allocations with the mass- and energy-content-based weighting factors is smaller than that predicted with the refinery-level allocations. However, the process-level allocation with the market-value-based weighting factors has results very close to those obtained by using the refinery-level allocations. For LPG, the refinery-level allocation significantly overestimates LPG energy use. For naphtha, the refinery-level allocation overestimates naphtha energy use. The GHG emission patterns for each of the fuels are similar to those of energy use. Conclusions  We presented a refining-process-level-based method that can be used to allocate energy use of individual refining processes to refinery products. The process-level-based method captures process-dependent characteristics of fuel production within a petroleum refinery. The method starts with the mass and energy flow chart of a refinery, tracks energy use by individual refining processes, and distributes energy use of a given refining process to products from the process. In allocating energy use to refinery products, the allocation method could rely on product mass, product energy contents, or product market values as weighting factors. While the mass- and energy-content-based allocation methods provide an engineering perspective of energy allocation within a refinery, the market-value-based allocation method provides an economic perspective. The results from this study show that energy allocations at the aggregate refinery level and at the refining process level could make a difference in evaluating the energy use and emissions associated with individual petroleum products. Furthermore, for the refining-process-level allocation method, use of mass — energy content- or market value share-based weighting factors could lead to different results for diesel fuels, LPG, and naphtha. We suggest that, when possible, energy use allocations should be made at the lowest subprocess level — a confirmation of the recommendation by the International Standard Organization for life cycle analyses. Outlook  The allocation of energy use in petroleum refineries at the refining process level in this study follows the recommendation of ISO 14041 that allocations should be accomplished at the subprocess level when possible. We developed a method in this study that can be readily adapted for refineries in which process-level energy and mass balance data are available. The process-level allocation helps reveal some additional energy and emission burdens associated with certain refinery products that are otherwise overlooked with the refinery-level allocation. When possible, process-level allocation should be used in life-cycle analyses.     

Cradle-to-gate life cycle inventory and assessment of pharmaceutical compounds

Background, Goal and Scope  The research presented here represents one part of GlaxoSmithKline’s (GSK) efforts to identify and improve the life cycle impact profile of pharmaceutical products. The main goal of this work was to identify and analyze the cradle-to-gate environmental impacts in the synthesis of a typical Active Pharmaceutical Ingredient (API). A cradle-to-gate life cycle assessment of a commercial pharmaceutical product is presented as a case study. Methods  Life cycle inventory data were obtained using a modular gate-to-gate methodology developed in partnership with North Carolina State University (NCSU) while the impact assessment was performed utilizing GSK’s sustainability metrics methodology. Results and Discussion  Major contributors to the environmental footprint of a typical pharmaceutical product were identified. The results of this study indicate that solvent use accounts for a majority of the potential cradle-to-gate impacts associated with the manufacture of the commercial pharmaceutical product under study. If spent solvent is incinerated instead of recovered the life-cycle profile and impacts are considerably increased. Conclusions  This case study provided GSK with key insights into the life-cycle impacts of pharmaceutical products. It also helped to establish a well-documented approach to using life cycle within GSK and fostered the development of a practical methodology that is applicable to strategic decision making, internal business processes and other processes and tools.     

Integrating cost-benefits analysis and life cycle assessment of green roofs: a case study in Florida

Abstract

Multiple environmental benefits can be achieved by using a green roof instead of conventional roofs. To better understand the LCA and cost-effectiveness of a green roof, a case study was performed. Two energy models, one with conventional white roof and the other with green roof, were created using eQUEST software to compare the influence of green roof on building energy consumption. The results indicated that the application of a green roof reduced annual space heating and cooling electricity consumption by 9500 kWh (2.2 kWh per square meter). The LCA shows that by using an extensive green roof in lieu of a conventional white roof the LCA measures at the product, construction, and end-of-life stages increased due to the use of additional layers. However, these increases are offset by the reduction of LCA measures at the use stage such that the overall environmental impacts of green roof is less than that of conventional roof. To find out the cost-effectiveness of green roof, a 50-year cost-benefits analysis was conducted. The analysis showed that the net savings of the green roof is negative compared to the white roof it replaced due to its higher initial cost and follow on maintenance cost.     

环境足迹的核算与整合框架——基于生命周期评价的视角

环境足迹及其与生命周期评价(LCA)的关系是工业生态学关注的新热点。从探讨环境足迹与LCA的关系入手,以碳足迹、水足迹、土地足迹和材料足迹为例,分别对每一项足迹指标两个版本的核算方法进行了比较。根据清单加和过程的特点,将所有足迹指标划分为基于权重因子和基于特征因子两类,总结了两者的适用性和局限性。在此基础上提出了一个环境足迹核算与整合的统一框架。该框架基于LCA视角建立,但对系统边界和清单数据的要求相对灵活,因而也适用于生命周期不甚明确的情形。研究在一定程度上揭示了足迹指标的方法学实质,同时也为环境影响综合评估提供了一条规范化的途径。     

中国生命周期评价理论与实践研究进展及对策分析

主要分析了我国生命周期评价的理论与实践研究进展与数据库构建现状,针对当前我国生命周期评价理论与应用研究的关键薄弱环节即不确定性分析、本土化数据库构建、本土化生命周期环境影响评价模型构建,指出了利用泰勒系列展开模型进行符合我国产业链生产现状的精确、完整、具有代表性、具有时空动态特征的生命周期数据库构建的必要性;并指出需要根据我国国情(例如:环境、地理、人口、暴露等)来构建生命周期环境影响评价模型的紧迫性。     

Reduction and reallocation of water use of products in Beijing

The virtual water concept has received significant attention through manifesting the role of human activities such as consumption and international trade on water resources. However, few studies have focused on how the interactions of local supply chain exert impact on local water resources associated with virtual water flows. In this study, we introduce an indicator which is attached to the virtual water concept, termed the “internal water use of products” (IWUP), to examine the direct and indirect water use from local water supply for goods and services in Beijing for the years 1997, 2000, 2002, 2007, and 2010. This indicator links the pressure on local water resources to the final products with sectoral details, highlighting the importance of economic analysis in local water resource management. A structural decomposition analysis revealed that the increase in economic water productivity would have caused Beijing's IWUP to decrease by 196% from 1997 to 2010, if other determining factors remained constant. Such great efficiency improvements have allowed Beijing to fulfill its objectives of economic growth, whilst in the meantime reducing the water used in production. However, we also found that production structure adjustment would increase the IWUP, mainly due to a shift from agricultural and industrial sectors to service sectors.     

Beyond Global Warming Potential: A Comparative Application of Climate Impact Metrics for the Life Cycle Assessment of Coal and Natural Gas Based Electricity

In the ongoing debate about the climate benefits of fuel switching from coal to natural gas for power generation, the metrics used to model climate impacts may be important. In this article, we evaluate the life cycle greenhouse gas emissions of coal and natural gas used in new, advanced power plants using a broad set of available climate metrics in order to test for the robustness of results. Climate metrics included in the article are global warming potential, global temperature change potential, technology warming potential, and cumulative radiative forcing. We also used the Model for the Assessment of Greenhouse‐gas Induced Climate Change (MAGICC) climate‐change model to validate the results. We find that all climate metrics suggest a natural gas combined cycle plant offers life cycle climate benefits over 100 years compared to a pulverized coal plant, even if the life cycle methane leakage rate for natural gas reaches 5%. Over shorter time frames (i.e., 20 years), plants using natural gas with a 4% leakage rate have similar climate impacts as those using coal, but are no worse than coal. If carbon capture and sequestration becomes available for both types of power plants, natural gas still offers climate benefits over coal as long as the life cycle methane leakage rate remains below 2%. These results are consistent across climate metrics and the MAGICC model over a 100‐year time frame. Although it is not clear whether any of these metrics are better than the others, the choice of metric can inform decisions based on different societal values. For example, whereas annual temperature change reported may be a more relevant metric to evaluate the human health effects of increased heat, the cumulative temperature change may be more relevant to evaluate climate impacts, such as sea‐level rise, that will result from the cumulative warming.     

Use of Symbiosis Products from Integrated Pulp and Paper and Carbon Steel Mills: Legal Status and Environmental Burdens

This study assesses the policy/legal status of both multistream residues and potential secondary products (“symbiosis products”) and whether there could be environmental benefits associated with the utilization of residues from integrated pulp and paper and carbon steel mills as raw materials for such secondary products. Waste‐related European Union (EU) and Finnish policy and legal instruments were reviewed to identify potential constraints for, and suggested next steps in, the development of potential process industry residue‐based symbiosis products. The products were soil amendment pellets, low‐grade concrete, and mine filler. A global warming potential (GWP) assessment and an exergy analysis were applied to these potential symbiosis products. Some indicative GWP calculations of greenhouse gas emissions associating similar and/or analogous products based on virgin primary raw materials, more energy‐intensive processes, and the alternative treatment of these residues as wastes are also presented. This study addresses GWP, exergy, and legal aspects in a holistic manner to determine the potential environmental benefits of secondary products within the EU legal framework. The GWP assessment and exergy analysis indicate that the utilization of multistream residues causes very low environmental burdens in terms of GWP. The utilization option can have potential environmental benefits in terms of GWP through process replacement and avoided landfilling and waste treatment impacts, as well as potentially through emission reductions from product replacement if suitable and safe applications can be identified. Waste regulation does not define the legal requirements under which utilizing residues in such novel concepts as introduced in this study would be possible, nor how waste status could be removed and product‐based legislation be applied to the potential products instead.     

Drought-induced dynamics of carbon and water use efficiency of global grasslands from 2000 to 2011

Drought is frequently recorded as a result of climate warming and elevated concentration of greenhouse gases, which affect the carbon and water cycles in terrestrial ecosystems, particularly in arid and semi-arid regions. To identify the drought in grassland ecosystems and to determine how such drought affects grassland ecosystems in terms of carbon and water cycles across the globe, this study evaluated the drought conditions of global grassland ecosystems from 2000 to 2011 on the basis of the remotely sensed Drought Severity Index (DSI) data. The temporal dynamics of grassland carbon use efficiency (CUE) and water use efficiency (WUE), as well as their correlations with DSI, were also investigated at the global scale. Results showed that 57.04% of grassland ecosystems experienced a dry trend over this period. In general, most grassland ecosystems in the northern hemisphere (N.H.) were in near normal condition, whereas those in the southern hemisphere (S.H.) experienced a clear drying and wetting trend, with the year 2005 regarded as the turning point. Grassland CUE increased continually despite the varied drought conditions over this period. By contrast, WUE increased in the closed shrublands and woody savannas but decreased in all the other grassland types. The drought conditions affected the carbon and water use mainly by influencing the primary production and evapotranspiration of grass through photosynthesis and transpiration process. The CUE and WUE of savannas was most sensitive to droughts among all the grassland types. The areas of grassland DSI that showed significant correlations with CUE and WUE were 52.92% and 22.11% of the total grassland areas, respectively. Overall, droughts sufficiently explained the dynamics of grassland CUE, especially in the S.H. In comparison with grassland CUE, the grassland WUE was less sensitive to drought conditions at the global scale.